U.S. patent application number 16/315970 was filed with the patent office on 2019-07-25 for n-vinyl lactam-based crosslinked polymer, cosmetic, absorbent agent for ink and absorbent composite.
The applicant listed for this patent is NIPPON SHOKUBAI CO., LTD.. Invention is credited to Yui IKEMOTO, Kazuhiro OKAMURA.
Application Number | 20190224644 16/315970 |
Document ID | / |
Family ID | 60912823 |
Filed Date | 2019-07-25 |
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United States Patent
Application |
20190224644 |
Kind Code |
A1 |
IKEMOTO; Yui ; et
al. |
July 25, 2019 |
N-VINYL LACTAM-BASED CROSSLINKED POLYMER, COSMETIC, ABSORBENT AGENT
FOR INK AND ABSORBENT COMPOSITE
Abstract
The invention aims to provide an absorbent composite having an
excellent absorption capacity for various liquids. The invention
relates to an absorbent composite including: a nonionic crosslinked
polymer; and an absorbent base material, the absorbent composite
having a mass ratio of the nonionic crosslinked polymer to the
absorbent base material (nonionic crosslinked polymer/absorbent
base material) of 0.1 or more and less than 2.
Inventors: |
IKEMOTO; Yui; (Osaka,
JP) ; OKAMURA; Kazuhiro; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIPPON SHOKUBAI CO., LTD. |
Osaka-shi, Osaka |
|
JP |
|
|
Family ID: |
60912823 |
Appl. No.: |
16/315970 |
Filed: |
July 7, 2017 |
PCT Filed: |
July 7, 2017 |
PCT NO: |
PCT/JP2017/025037 |
371 Date: |
January 7, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 39/04 20130101;
A61Q 1/00 20130101; C08J 2423/12 20130101; B41J 2/16517 20130101;
B01J 20/3078 20130101; A61Q 19/00 20130101; C08J 2439/06 20130101;
A61L 2209/22 20130101; C08J 2339/06 20130101; A61K 8/0204 20130101;
A61K 8/817 20130101; B01J 20/267 20130101; A61Q 15/00 20130101;
A61K 8/027 20130101; C08F 226/10 20130101; C08J 5/24 20130101; A61K
2800/546 20130101; B01J 20/28033 20130101; C08F 220/286 20200201;
A61L 9/014 20130101; B01J 20/28023 20130101; A61K 2800/5422
20130101; B01J 20/3085 20130101; A61K 8/8182 20130101; B01J 20/3014
20130101; A61Q 5/00 20130101; C09D 11/106 20130101; A61K 8/81
20130101; B01J 20/3021 20130101; C08F 26/06 20130101; C08L 2203/02
20130101; A61L 2209/14 20130101; A61L 9/01 20130101; C08F 26/10
20130101; C08J 2323/12 20130101; C09D 11/03 20130101; C08F 226/10
20130101; C08F 226/06 20130101; C08F 226/10 20130101; C08F 216/125
20130101; C08F 220/286 20200201; C08F 220/20 20130101; C08F 222/102
20200201 |
International
Class: |
B01J 20/26 20060101
B01J020/26; A61Q 15/00 20060101 A61Q015/00; A61Q 19/00 20060101
A61Q019/00; A61K 8/81 20060101 A61K008/81; A61K 8/02 20060101
A61K008/02; C08F 26/10 20060101 C08F026/10; C08J 5/24 20060101
C08J005/24; B01J 20/28 20060101 B01J020/28; B01J 20/30 20060101
B01J020/30; A61L 9/014 20060101 A61L009/014; B41J 2/165 20060101
B41J002/165 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2016 |
JP |
2016-136038 |
Jul 26, 2016 |
JP |
2016-146535 |
Sep 9, 2016 |
JP |
2016-176596 |
Nov 25, 2016 |
JP |
2016-229398 |
Dec 28, 2016 |
JP |
2016-255516 |
Feb 27, 2017 |
JP |
2017-035357 |
Feb 27, 2017 |
JP |
2017-035358 |
Claims
1. An absorbent composite comprising: a nonionic crosslinked
polymer; and an absorbent base material, the absorbent composite
having a mass ratio of the nonionic crosslinked polymer to the
absorbent base material (nonionic crosslinked polymer/absorbent
base material) of 0.1 or more and less than 2.
2. The absorbent composite according to claim 1, wherein the
nonionic crosslinked polymer comprises a structural unit derived
from an amide monomer and/or a structural unit derived from a
(poly)alkylene glycol monomer.
3. The absorbent composite according to claim 1, wherein the
absorbent base material comprises a hydrophilic fiber.
4. The absorbent composite according to claim 3, wherein the
hydrophilic fiber is at least one selected from the group
consisting of cellulosic fibers, polyamide fibers, animal fibers,
and hydrophobic fibers having a hydrophilic surface layer.
5. The absorbent composite according to claim 1, wherein the
absorbent base material has a sheet shape or a bag shape.
6. A deodorant comprising the absorbent composite according to
claim 1.
7. A deodorizer comprising the deodorant according to claim 6.
8. A method of using the deodorant according to claim 6, the
deodorant being incorporated into a deodorizer.
9. A cosmetic comprising the absorbent composite according to claim
1.
10. A method of using the absorbent composite according to claim 1
as a cosmetic.
11. An ink absorber comprising the absorbent composite according to
claim 1.
12. An absorbent material comprising the ink absorber according to
claim 11.
13. An ink-absorbed body comprising the ink absorber according to
claim 11 and ink absorbed by the ink absorber.
14. A printer comprising the ink absorber according to claim
11.
15. A method of using the ink absorber according to claim 11, the
ink absorber being incorporated into a printer.
Description
TECHNICAL FIELD
[0001] The invention relates to a N-vinyl lactam-based crosslinked
polymer, a cosmetic, an absorbent composite, and an ink absorbing
agent. The invention specifically relates to a N-vinyl lactam-based
crosslinked polymer, a cosmetic, an absorbent composite, and an ink
absorbing agent useful for skin cosmetics, skin preparations for
external use, hair cosmetics, ink absorbing agents for use in
writing instruments and ink jet recording apparatuses, deodorants,
and fragrance agents, for example.
BACKGROUND ART
[0002] Polymers having a lactam structure, which have
hydrophilicity and are highly safe to the human body and the
environment, are used in various applications.
[0003] In particular, crosslinked polymers having a lactam
structure are useful in applications for absorption and retention
of liquid such as water, and are therefore widely used as
water-absorbent (liquid-absorbent) resins for disposable diapers,
for example. With regard to such liquid-absorbent resins, Patent
Literature Documents 1 to 4 disclose liquid-absorbent resins
prepared by copolymerizing a monomer component containing a cyclic
vinyl lactam with a crosslinking agent or production methods
thereof.
[0004] Further, crosslinked polymers having a lactam structure are
blended into various cosmetic products as a carrier for a
surfactant, a fragrance component, a deodorant component, or a
cosmetic component; a humectant; a thickening agent; or a
dispersant (see Patent Literature Documents 5 to 7).
[0005] Water-absorbent materials primarily containing a polyacrylic
acid (salt) have been conventionally developed and have been used
in various fields such as the hygiene field including the field of
hygiene articles (e.g., diapers, sanitary products), the medical
field, the civil engineering and construction field, the food
field, the industrial field, the field of soil modifiers, and the
agriculture/horticulture field.
[0006] For example, Patent Literature Documents 8 to 10 disclose an
absorbent composite or ink absorber which includes a base material
and a crosslinked body primarily containing a polyacrylic acid
(salt).
[0007] Further, writing utensils such as ball-point pens and
coating utensils are equipped with an ink absorber that absorbs an
excess ink or keeps the density of a reserved ink uniform (see
Patent Literature Documents 11 to 17).
CITATION LIST
Patent Literature
Patent Literature 1: JP H10-5582 A
Patent Literature 2: JP H10-101745 A
Patent Literature 3: JP 2001-226431 A
Patent Literature 4: JP 2012-072277 A
Patent Literature 5: JP 2007-45776 A
Patent Literature 6: JP 2012-520317 T
[0008] Patent Literature 7: U.S. Pat. No. 5,139,770
Patent Literature 8: JP 2008-86590 A
Patent Literature 9: JP 2009-274302 A
Patent Literature 10: JP 2000-135797 A
Patent Literature 11: JP 2005-219482 A
Patent Literature 12: JP 2001-301379 A
Patent Literature 13: JP H09-183231 A
Patent Literature 14: JP 2000-135797 A
Patent Literature 15: JP 2000-239342 A
Patent Literature 16: JP 2009-274302 A
Patent Literature 17: JP 2006-272734 A
SUMMARY OF INVENTION
Technical Problem
[0009] In order to use such N-vinyl lactam-based crosslinked
polymers as disclosed above in various applications, they need to
have, in addition to an excellent liquid absorption capacity,
sufficient gel-pulverizability. However, conventional N-vinyl
lactam-based crosslinked polymers are not enough to satisfy a
liquid absorption capacity and sufficient gel-pulverizability at
the same time. For cosmetic applications, crosslinked polymers need
to have not only excellent moisture retention properties, but also
excellent absorption capacity for ethanol usually contained in
cosmetics, excellent adhesiveness to the skin when applied to the
skin as a cosmetic, and a high concentration of an effective
component.
[0010] Although various cosmetics such as cosmetics containing a
moisturizer as an additive are disclosed, recent consumer demand
for safety has led to a need for development of cosmetics
containing an additive that is safer and contains particles having
better adhesiveness and better applicability to the skin.
[0011] The above-described various absorbent composites (ink
absorbers) have problems as follows. Conventional absorbent
composites primarily containing a polyacrylic acid (salt) are
capable of absorbing only water and a water-rich solution. For
example, conventional absorbent composites are capable of absorbing
an organic solvent as a water-rich aqueous solution. However, when
the water evaporates and the organic solvent component is
concentrated, the absorbent composite cannot hold the liquid any
longer, causing liquid leakage (discharge). In order to solve such
a problem, an absorbent composite having an excellent absorption
capacity for various liquids is required to be developed.
[0012] Further, although various ink absorbers and ink absorbing
agents have been developed as described above, the ink absorbers
and the ink absorbing agents disclosed in Patent Literature
Documents 11 to 16 are not satisfactory in terms of liquid
absorption capacity because they cannot absorb a sufficient amount
of ink or sufficient types of ink. In addition, the invention
disclosed in Patent Literature 17 only relates to easy absorption
(without foaming) of ink with an absorber by impregnating the
absorber with an emulsion or applying an emulsion to the surface of
the absorber, for example. An emulsion is not used for holding ink,
and the absorber itself has a low absorption capacity.
[0013] The invention has been made in view of the above-mentioned
state of the art and aims to provide a crosslinked polymer having
an excellent liquid absorption capacity and sufficient
gel-pulverizability.
[0014] The invention also aims to provide a crosslinked polymer
having excellent moisture retention properties, an excellent
ethanol absorption capacity, excellent adhesiveness to the skin
when applied to the skin as a cosmetic, and a high concentration of
an effective component.
[0015] The invention also aims to provide a cosmetic better than
conventional cosmetics, that is, a cosmetic containing an additive
that is safer for the human body and has better adhesiveness to the
skin, and a cosmetic containing an additive that is safer for the
human body and has better applicability to the skin.
[0016] The invention also aims to provide an absorbent composite
having an excellent absorption capacity for various liquids.
[0017] The invention also aims to provide an ink absorbing agent
having a better ink absorption capacity than conventional ink
absorbing agents.
Solution to Problem
[0018] The inventors variously studied a crosslinked polymer having
an excellent liquid absorption capacity and gel-pulverizability and
found that a N-vinyl lactam-based crosslinked polymer containing a
structural unit derived from a cyanuric acid structure-containing
crosslinkable monomer in a ratio within a specific range has an
excellent liquid absorption capacity and sufficient
gel-pulverizability. As a result, they arrived at an admirable
solution to the above-mentioned problems, completing a first aspect
of the invention.
[0019] The inventors also variously studied a crosslinked polymer
and found that a N-vinyl lactam-based crosslinked polymer having an
aspect ratio within a specific range and a specific water
absorption capacity has excellent moisture retention properties, an
excellent ethanol absorption capacity, excellent adhesiveness to
the skin when applied to the skin as a cosmetic, and a high
concentration of an effective component. As a result, they arrived
at an admirable solution to the above-mentioned problems,
completing a second aspect of the invention.
[0020] The inventors also variously studied a cosmetic and found
that a cyclic N-vinyl lactam-based crosslinked body having a
particle aspect ratio of 1.15 to 10 and including a structural unit
derived from a cyclic N-vinyl lactam is highly safe, and exerts
moisturizing, oil-absorbing, and thickening effects, and has
excellent adhesiveness to the skin. They also found that a cyclic
N-vinyl lactam-based crosslinked polymer including a structural
unit derived from a cyclic N-vinyl lactam is highly safe, exerts
moisturizing and oil-absorbing effects, and has good applicability
to the skin when it is used in the form of a 5 mass % aqueous
dispersion having a viscosity of 100 mPas or higher and lower than
10000 mPas. They found that such a crosslinked body and a
crosslinked polymer are suitable for cosmetic applications. As a
result, they arrived at an admirable solution to the
above-mentioned problems, completing a third aspect of the
invention.
[0021] The inventors also variously studied an absorbent composite
and found that an absorbent composite containing a nonionic
crosslinked polymer and an absorbent base material has excellent
absorption performance to various types of liquids when the
absorbent composite has a mass ratio between the nonionic
crosslinked polymer and the absorbent base material within a
specific range or a thickness within a specific range. As a result,
they arrived at an admirable solution to the above-mentioned
problems, completing a fourth aspect of the invention.
[0022] The inventors also variously studied an ink absorbing agent
and found that a N-vinyl lactam-based crosslinked polymer has an
excellent liquid absorption capacity in terms of both the amount
and types of ink and is suitable as an ink absorbing agent. As a
result, they arrived at an admirable solution to the
above-mentioned problems, completing a fifth aspect of the
invention.
[0023] That is, the first aspect of the invention relates to a
N-vinyl lactam-based crosslinked polymer including:
[0024] a structural unit derived from a N-vinyl lactam-based
monomer; and
[0025] a structural unit derived from a cyanuric acid
structure-containing crosslinkable monomer,
[0026] the N-vinyl lactam-based crosslinked polymer containing the
structural unit derived from a cyanuric acid structure-containing
crosslinkable monomer in a ratio of 0.12 to 0.48 mol % to 100 mol %
of all structural units.
[0027] The second aspect of the invention relates to a N-vinyl
lactam-based crosslinked polymer including a structural unit
derived from a N-vinyl lactam and a structural unit derived from a
crosslinking agent. The N-vinyl lactam-based crosslinked polymer
has an ethanol absorption capacity of 3 to 40 g per 1 g of the
N-vinyl lactam-based crosslinked polymer, contains particles having
an aspect ratio determined by the method described below of 1.15 to
10 in a proportion of 10% to 100% (by number) of the total number
of the N-vinyl lactam-based crosslinked polymer, and has a
proportion of an extractable of 35 mass % or less in 100 mass % of
the entire polymer.
<Method of Measuring Aspect Ratio>
[0028] The aspect ratio is determined as a value obtained by
measuring the major and minor axes of a primary particle of the
N-vinyl lactam-based cross-linked polymer with an optical or
electron microscope and dividing the major axis by the minor
axis.
[0029] A first embodiment of the third aspect of the invention
relates to a cosmetic that includes a cyclic N-vinyl lactam-based
crosslinked body including a structural unit derived from a cyclic
N-vinyl lactam. The cyclic N-vinyl lactam-based crosslinked body is
a cosmetic having a viscosity measured under the following
conditions of 100 mPas or higher and lower than 10000 mPas.
<Viscosity Measurement Conditions>
[0030] Sample: A 5 mass % aqueous dispersion of the cyclic N-vinyl
lactam-based crosslinked body after 16-hour stirring
[0031] Measuring equipment: The sample is measured using a B-type
viscometer at 25.degree. C.
[0032] Measurement conditions: Rotor No. 4, rotation speed: 30
rpm
[0033] A second embodiment of the third aspect of the invention
relates to a cosmetic that includes a cyclic N-vinyl lactam-based
crosslinked polymer including a structural unit derived from a
cyclic N-vinyl lactam. The cyclic N-vinyl lactam-based crosslinked
polymer in particulate form contains particles having an aspect
ratio determined by the method described below of 1.1 to 10 in a
proportion of 10% to 100% (by number) of the total number of the
cyclic N-vinyl lactam-based crosslinked polymer particles.
<Method of Measuring Aspect Ratio>
[0034] The aspect ratio is determined as a value obtained by
measuring the major and minor axes of a primary particle of the
cyclic N-vinyl lactam-based cross-linked polymer with an optical or
electron microscope and dividing the major axis by the minor
axis.
[0035] A first embodiment of the fourth aspect of the invention
relates to an absorbent composite including a nonionic crosslinked
polymer and an absorbent base material, the absorbent composite
having a mass ratio of the nonionic crosslinked polymer to the
absorbent base material (nonionic crosslinked polymer/absorbent
base material) of 0.1 or more and less than 2.
[0036] A second embodiment of the fourth aspect of the invention
relates to an absorbent composite including a nonionic crosslinked
polymer and an absorbent base material, the absorbent composite
having a mass ratio of the nonionic crosslinked polymer to the
absorbent base material (nonionic crosslinked polymer/absorbent
base material) of 2.5 or more and not more than 15.
[0037] The fifth aspect of the invention relates to an ink
absorbing agent containing a N-vinyl lactam-based crosslinked
polymer.
Advantageous Effects of Invention
[0038] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention having the above-described features has an
excellent liquid absorption capacity and sufficient
gel-pulverizability and is suitable for ink absorbing agents for
use in writing instruments and ink jet recording apparatuses,
deodorants, fragrance agents, and cosmetics, for example.
[0039] The N-vinyl lactam-based crosslinked polymer of the second
aspect of the invention having the above-described features has
excellent moisture retention properties, an excellent ethanol
absorption capacity, excellent adhesiveness to the skin when
applied to the skin as a cosmetic, and a high concentration of an
effective component. Such a N-vinyl lactam-based crosslinked
polymer is suitable for cosmetics, for example.
[0040] The cosmetic of the third aspect of the invention having the
above-described features contains an additive safer for the human
body than additives contained in conventional cosmetics. Such a
cosmetic is suitable for skin cosmetics, skin preparations for
external use, and hair cosmetics, for example.
[0041] The absorbent composite of the fourth aspect of the
invention having the above-described features has an excellent
absorption capacity for various liquids and is suitable for
absorbent materials for inks, for example.
[0042] The ink absorbing agent of the fifth aspect of the invention
having the above-described features has an excellent ink absorption
capacity and is suitable for ink jet recording apparatuses and
writing instruments, for example.
[0043] The following specifically describes the invention. The
matters referring to "the invention" herein are common to the first
to fifth aspects of the invention.
[0044] A combination of two or more of the preferred embodiments of
the invention described below is also a preferred embodiment of the
invention.
<First Aspect of the Invention: N-Vinyl Lactam-Based Crosslinked
Polymer>
[0045] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention (hereinafter, also referred to as
crosslinked polymer of the first aspect of the invention) includes
a structural unit derived from a N-vinyl lactam (N-vinyl
lactam-based monomer).
[0046] The "structural unit derived from a N-vinyl lactam"
indicates a structural unit having the same structure as the
structural unit formed by polymerizing a N-vinyl lactam (N-vinyl
lactam-based monomer). That is, the structural unit derived from a
N-vinyl lactam encompasses a structural unit formed by a method
other than polymerization of a N-vinyl lactam as long as it has the
same structure as the structural unit formed by polymerizing a
N-vinyl lactam. The crosslinked polymer of the first aspect of the
invention including a structural unit derived from a N-vinyl lactam
is capable of absorbing or retaining water or other solvents, and
thus can be used in various applications as described below.
[0047] The crosslinked polymer of the first aspect of the invention
is capable of absorbing solvents such as an oil, and is thus
suitable for applications of an ink absorbing agent for use in
writing instruments and ink jet recording apparatuses.
[0048] The crosslinked polymer of the first aspect of the invention
is also capable of absorbing odor components, and is thus suitable
for deodorant applications. The crosslinked polymer is also capable
of exerting fragrance effects by absorbing a fragrance component,
and is thus suitable for fragrance applications.
[0049] The crosslinked polymer of the first aspect of the invention
is capable of exerting a moisturizing effect by absorbing and
retaining liquids such as water. Further, the nonionic properties
of the N-vinyl lactam make the crosslinked polymer highly safe, and
such a crosslinked polymer is suitable for cosmetic applications.
The crosslinked polymer having a crosslinked structure swells into
a gel when the polymer absorbs water or other solvents. Therefore,
the polymer exerts a thickening effect and further enhances the
adhesiveness to the skin of a cosmetic containing the polymer.
[0050] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention includes a structural unit derived from a
cyanuric acid structure-containing crosslinkable monomer.
[0051] Herein, the cyanuric acid structure-containing crosslinkable
monomer means a crosslinkable monomer having a structure obtained
by removing at least two hydrogen atoms from a cyanuric acid
(hereinafter, also referred to as cyanuric acid-derived structure)
and at least two carbon-carbon double bonds. The at least two
carbon-carbon double bonds of the cyanuric acid
structure-containing crosslinkable monomer each react with a
carbon-carbon double bond of another molecule, so that a
crosslinked structure is formed.
[0052] Since the cyanuric acid structure-containing crosslinkable
monomer is highly reactive with a N-vinyl lactam, the presence of
the cyanuric acid structure-containing crosslinkable monomer can
reduce an extractable (uncrosslinked polymer soluble in water) in
the crosslinked polymer. As a result, the concentration of an
effective component in the crosslinked polymer increases, and a
better liquid absorption capacity is obtained.
[0053] The crosslinked polymer contains the structural unit derived
from a cyanuric acid structure-containing crosslinkable monomer in
a ratio of 0.12 to 0.48 mol % to 100 mol % of all structural units.
The crosslinked polymer having such a ratio of the structural unit
retains a high liquid absorption capacity and has suitable gel
strength and thus has more sufficient gel-pulverizability. Also,
the cyanuric acid structure-containing crosslinkable monomer has
less skin irritation and is highly safe. Thus, the N-vinyl
lactam-based crosslinked polymer of the first aspect of the
invention is suitable for cosmetic applications. The ratio of the
structural unit is preferably 0.12 to 0.47 mol %, more preferably
0.13 to 0.47 mol %, still more preferably 0.15 to 0.47 mol %,
particularly preferably 0.15 to 0.45 mol %, most preferably 0.16 to
0.45 mol %.
[0054] Here, the ratio of the structural unit derived from a
cyanuric acid structure-containing crosslinkable monomer may be
determined by the expression:
[Structural unit derived from cyanuric acid structure-containing
crosslinkable monomer (number of moles)]/[all structural units (sum
of structural unit derived from N-vinyl lactam and structural unit
derived from monomer (E)) (number of moles)].times.100 (mol %).
[0055] The cyanuric acid structure-containing crosslinkable monomer
may be any monomer having a cyanuric acid-derived structure and at
least two carbon-carbon double bonds and is preferably a monomer
represented by the following formula 1):
##STR00001##
wherein R.sup.1, R.sup.2, and R.sup.3 are the same as or different
from each other and each represent a hydrogen atom or an optionally
substituted C1-C10 alkyl group; m's are the same as or different
from each other and each represent an integer of 0 to 4.
[0056] The number of carbon atoms of the alkyl group for R.sup.1 to
R.sup.3 is preferably 1 to 6, more preferably 1 to 4. The alkyl
group is still more preferably a methyl group or an ethyl group,
particularly preferably a methyl group.
[0057] Examples of the substituent in R.sup.1 to R.sup.3 include,
but are not limited to, an ethylenically unsaturated hydrocarbon
group; a carboxyl group and a sulfonic acid group and esters and
salts thereof; and a reactive functional group condensable with a
crosslinking agent, such as an amino group or a hydroxy group.
[0058] R.sup.1 to R.sup.3 each preferably represent a hydrogen
atom.
[0059] Further, m is preferably 0, 1, or 2, more preferably 1.
[0060] The compound represented by the formula (1) is preferably
triallyl cyanurate.
[0061] The "N-vinyl lactam" may be any monomer having a N-vinyl
lactam structure, preferably a structure represented by the
following formula (2):
##STR00002##
wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same as or
different from each other and each represent a hydrogen atom or an
optionally substituted C1-C10 alkyl group; x represents an integer
of 0 to 4; and y represents an integer of 1 to 3.
[0062] The number of carbon atoms of the alkyl group for R.sup.1 to
R.sup.4 is preferably 1 to 6, more preferably 1 to 4. The alkyl
group is still more preferably a methyl group or an ethyl group,
particularly preferably a methyl group.
[0063] Examples of the substituent in R.sup.1 to R.sup.4 include,
but are not limited to, an ethylenically unsaturated hydrocarbon
group; a carboxyl group, a sulfonic acid group, and esters and
salts thereof; and a reactive functional group condensable with a
crosslinking agent, such as an amino group or a hydroxy group.
[0064] In cases where at least one of R.sup.1 to R.sup.4 in the
formula (2) is a C1-C10 alkyl group containing as a substituent a
reactive functional group condensable with a crosslinking agent, a
crosslinked structure can be formed by the following process (2) or
(3).
[0065] R.sup.1 to R.sup.3 each preferably represent a hydrogen
atom. R.sup.4 preferably represents a hydrogen atom or a methyl
group, more preferably a hydrogen atom.
[0066] Further, x is preferably an integer of 0 to 2, more
preferably an integer of 0 or 1, most preferably 0.
[0067] Further, y is preferably 1 or 2, more preferably 1.
[0068] Examples of the compound represented by the formula (2)
include N-vinylpyrrolidone, N-vinyl-5-methylpyrrolidone,
N-vinylpiperidone, N-vinylcaprolactam, and
1-(2-propenyl)-2-pyrrolidone. One or two or more of these may be
used. The N-vinyl lactam is preferably an unsaturated monomer
having a pyrrolidone ring, more preferably N-vinylpyrrolidone.
[0069] The crosslinked polymer of the first aspect of the invention
may have a crosslinked structure other than, and in addition to,
the structural unit derived from a cyanuric acid
structure-containing crosslinkable monomer. The crosslinked
structure can be formed by any of the following processes (1) to
(5), for example.
[0070] (1) A monomer component containing a crosslinkable monomer
other than, and in addition to, the cyanuric acid
structure-containing crosslinkable monomer is polymerized to
produce a polymer having a crosslinked structure.
[0071] (2) A monomer component containing a reactive functional
group-containing monomer is polymerized to obtain a polymer, and
the polymer is reacted with a crosslinking agent having multiple
functional groups capable of reacting with the reactive functional
group to form a crosslinked structure.
[0072] (3) A monomer component containing a monomer 1 having a
reactive functional group and a monomer 2 having a reactive
functional group capable of reacting with the reactive functional
group of the monomer 1 is polymerized, and then the reactive
functional group of the monomer 1 is reacted with the reactive
functional group of the monomer 2 to form a crosslinked structure
(self-crosslinking).
[0073] (4) Radicals are produced in polymers, and a crosslinked
structure is formed between the polymers containing radicals
(self-crosslinking).
[0074] (5) Radicals are produced in a polymer, and the polymer
containing radicals is reacted with a crosslinkable monomer to form
a crosslinked structure.
[0075] The crosslinkable monomers in the processes (1) and (5) are
described below.
[0076] In the case of the crosslinked polymer of the first aspect
of the invention having a crosslinked structure formed by the
process (2) or (3), the crosslinked polymer of the first aspect of
the invention includes a structural unit derived from a reactive
functional group-containing monomer as the structural unit derived
from a N-vinyl lactam-based monomer or the structural unit derived
from a monomer (E) described below.
[0077] Examples the reactive functional groups in the processes (2)
and (3) include, but are not limited to, a carboxyl group, a
sulfonic acid group, and esters and salts thereof; an amino group;
and a hydroxy group.
[0078] In cases where the crosslinked structure is formed by the
process (3), examples of a combination of the reactive functional
groups reactive with each other include a combination of a carboxyl
group (or an ester or salt thereof) and a hydroxy group, a
combination of a sulfonic acid group (or an ester or salt thereof)
and a hydroxy group, a combination of a carboxyl group (or an ester
or salt thereof) and an amino group, a combination of a carboxyl
group (or an ester or salt thereof) and an oxazoline group, a
combination of a sulfonic acid group (or an ester or salt thereof)
and an amino group, a combination of an isocyanate group and a
hydroxy group, a combination of an isocyanate group and an amino
group, a combination of an oxazoline group and a hydroxy group, and
a combination of an oxazoline group and a mercapto group. In cases
where the crosslinked structure in the crosslinked polymer of the
first aspect of the invention is formed by the process (2),
examples of a combination of the reactive functional group of the
monomer and the functional groups of a crosslinking agent capable
of reacting with the reactive functional group are the same as the
aforementioned examples of the combination.
[0079] The crosslinking agent in the process (2) may be any one
that has multiple functional groups capable of reacting with the
reactive functional group. Examples thereof include
ethylenediamine, hexamethylenediamine, phenylenediamine, an
oxazoline group-containing polymer (EPOCROS, Nippon Shokubai Co.,
Ltd.), butanediol, tolylene diisocyanate, and hexamethylene
diisocyanate.
[0080] In cases where the crosslinked structure in the crosslinked
polymer of the invention is formed by the process (1) or (5), the
crosslinkable monomer is a compound having at least two
polymerizable ethylenically unsaturated hydrocarbon groups in one
molecule, preferably a compound having at least two radical
polymerizable ethylenically unsaturated hydrocarbon groups in one
molecule.
[0081] The N-vinyl lactam-based monomer and the crosslinkable
monomer both encompass a compound having a lactam structure and at
least two ethylenically unsaturated hydrocarbon groups.
[0082] Specific examples of the crosslinkable monomer other than
the cyanuric acid structure-containing crosslinkable monomer
include C1-C4 alkylene group-containing N,N'-alkylene
bis(meth)acrylamides such as N,N'-methylene bis(meth)acrylamide;
C1-C6 alkylene group-containing alkylene bis(N-vinylamides) such as
1,4-butylene bis(N-vinylamide); C1-C4 alkylene group-containing
(poly)alkylene glycol di(meth)acrylates such as (poly)ethylene
glycol di(meth)acrylate and (poly)propylene glycol
di(meth)acrylate; trimethylolpropane (di or tri)(meth)acrylates
optionally modified with a C1-C4 alkylene group-containing alkylene
oxide, such as trimethyrolpropane tri(meth)acrylate,
trimethylolpropane di(meth)acrylate, and ethylene oxide-modified
trimethyrolpropane tri(meth)acrylate; glycerol (di or
tri)(meth)acrylates such as glycerol tri(meth)acrylate and glycerol
acrylate methacrylate; pentaerythritol (di, tri, or
tetra)(meth)acrylates such as pentaerythritol tetra(meth)acrylate;
dipentaerythritol (di, tri, tetra, penta, or hexa)(meth)acrylates
such as dipentaerythritol hexa(meth)acrylate; pentaerythritol (di,
tri, or tetra)(meth)allyl ethers such as pentaerythritol
tri(meth)allyl ether; C9-C20 triallyl compounds such as triallyl
isocyanurate, triallyl phosphate, and triallylamine; C6-C20 diallyl
compounds such as diallyl carbonate and
1,3-bis(allyloxy)-2-propanol; C4-C20 (di or tri)vinyl compounds
such as divinyl ether, divinyl ketone, trivinylbenzene,
divinylethylene urea, divinyltoluene, and divinylxylene; C2-C20
diisocyanates such as tolylene diisocyanate and hexamethylene
diisocyanate; poly(meth)allyloxy alkanes,
N,N'-divinyl-2-imidazolidinone, N,N'-1,4-butylene
bis(N-divinylacetamide), and (di, tri, tetra, penta, hexa, hepta,
or octa)allyl sucrose. Each of these may be used alone, or two or
more of these may be used in combination.
[0083] Preferred among the crosslinkable monomers are the compounds
having at least two allyl groups because the use of such compounds
tends to reduce a residual N-vinyl lactam and an extractable
(uncrosslinked polymer fraction soluble in water). Specifically,
preferred are pentaerythritol (di, tri, or tetra)(meth)allyl
ethers, triallyl isocyanurate, triallyl phosphate, triallylamine,
diallyl carbonate, 1,3-bis(allyloxy)-2-propanol, divinylethylene
urea, 1,4-butylene bis(N-vinylamide), and (di, tri, tetra, penta,
hexa, hepta, or octa)allyl sucrose, for example.
[0084] More preferred are pentaerythritol (di, tri, or tetra)allyl
ethers and (di, tri, tetra, penta, hexa, hepta, or octa)allyl
sucrose. A N-vinyl lactam-based crosslinked polymer including a
structural unit derived from a pentaerythritol (di, tri, or
tetra)allyl ether or (di, tri, tetra, penta, hexa, hepta, or
octa)allyl sucrose is one preferred embodiment of the invention.
Such a crosslinked polymer is more suitable for cosmetic
applications because pentaerythritol (di, tri, or tetra)allyl
ethers and (di, tri, tetra, penta, hexa, hepta, or octa)allyl
sucrose are highly safe.
[0085] The polyalkylene glycol di(meth)acrylate preferably has 2 or
more and 50 or less, more preferably 2 or more and 20 or less,
still more preferably 2 or more and 10 or less oxyalkylene groups
in one molecule. In the polyalkylene glycol di(meth)acrylate, the
proportion of an oxyethylene group is preferably 50 to 100 mol %,
more preferably 80 to 100 mol % in 100 mol % of the oxyalkylene
groups.
[0086] In the case of the trimethylolpropane (di or
tri)(meth)acrylates modified with a C1-C4 alkylene group-containing
alkylene oxide, the average number of alkylene oxides added in one
molecule of each of the trimethylolpropane (di or
tri)(meth)acrylates is preferably the same as described above.
[0087] The structural unit derived from a crosslinkable monomer is
a structural unit having the same structure as the structural unit
in which at least one of the polymerizable carbon-carbon double
bond groups of the crosslinkable monomer is converted into a single
bond. That is, the structural unit derived from a crosslinkable
monomer encompasses a structural unit formed by polymerizing a
monomer other than the crosslinkable monomer to form a polymer and
post-crosslinking the polymer as long as the structural unit has
the same structure as the structural unit in which at least one of
the polymerizable carbon-carbon double bond groups of the
crosslinkable monomer is converted into a single bond.
[0088] The crosslinked polymer of the first aspect of the invention
may contain a structural unit (e) derived from a monomer (E) other
than the N-vinyl lactam-based monomer, the cyanuric acid
structure-containing crosslinkable monomer, the crosslinkable
monomer other than the cyanuric acid structure-containing
crosslinkable monomer, and the crosslinking agent. The monomer (E)
may be any compound that is copolymerizable with a N-vinyl
lactam-based monomer, is free from a lactam structure, and has one
ethylenically unsaturated hydrocarbon group. Examples of the
monomer (E) include (i) unsaturated monocarboxylic acids such as
acrylic acid and methacrylic acid and salts thereof; (ii)
unsaturated dicarboxylic acids such as fumaric acid, maleic acid,
methylene glutaric acid, and itaconic acid and salts thereof (which
may be either monovalent salts or divalent salts); (iii)
unsaturated sulfonic acids such as 3-allyloxy-2-hydroxypropane
sulfonic acid, (meth)allylsulfonic acid, and isoprene sulfonic acid
and salts thereof; (iv) hydroxyethyl (meth)acrylate, hydroxypropyl
(meth)acrylate, 3-(meth)allyloxy-1,2-dihydroxypropane; unsaturated
alcohols such as (meth)allyl alcohol and isoprenol; and alkylene
oxide adducts of these in which an alkylene oxide is added to a
hydroxy group of these; (v) (meth)acrylates such as methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and
cyclohexyl (meth)acrylate; (vi) N-substituted or unsubstituted
(meth)acrylamides such as (meth)acrylamide, N-monomethyl
(meth)acrylamide, N-monoethyl (meth)acrylamide, and N,N-dimethyl
(meth)acrylamide; (vii) vinyl aryl monomers such as styrene,
indene, and vinylaniline; (viii) alkenes such as ethylene,
propylene, butadiene, isobutylene, and octene; (ix) vinyl
carboxylates such as vinyl acetate and vinyl propionate; (x)
unsaturated amines such as N,N-dimethylaminoethyl (meth)acrylate,
N,N-dimethylaminoethyl (meth)acrylamide, vinylpyridine, and
vinylimidazole and salts and quaternized compounds thereof; (xi)
vinylamides such as vinylformamide, vinylacetamide, and
vinyloxazolidone; (xii) unsaturated anhydrides such as maleic
anhydride and itaconic anhydride; (xiii) vinyl ethylene carbonates
and derivatives thereof; (xiv) (meth)acrylic acid-2-sulfoethyl
ester and derivatives thereof; and (xv) vinyl ethers such as methyl
vinyl ether, ethyl vinyl ether, and butyl vinyl ether.
[0089] Preferred among these are the monomers listed as (i) to (x),
more preferred are the monomers listed as (i), (v), (vi), (vii),
(ix), and (x).
[0090] Each of these may be used alone, or two or more of these may
be used in combination.
[0091] Examples of the salts in (i) to (iii) and (x) include metal
salts, ammonium salts, and organic amine salts.
[0092] Examples of the alkylene oxide in (iv) include ethylene
oxide and propylene oxide. Preferred is a C1-C20 alkylene oxide,
and more preferred is a C1-C4 alkylene oxide. The number of moles
of alkylene oxide added in (iv) is preferably 0 to 50 mol, more
preferably 0 to 20 mol per 1 mol of each compound in (iv).
[0093] The monomer (E) is preferably a C2-C20 monomer, more
preferably a C2-C15 monomer, still more preferably a C2-C10
monomer. In cases where the monomer (E) is an alkylene oxide
adduct, the number of carbon atoms of the structural site other
than the alkylene oxide structural site preferably satisfies the
number of carbon atoms within these ranges.
[0094] In the N-vinyl lactam-based crosslinked polymer, the
proportion of the structural unit derived from a N-vinyl lactam is
preferably 30 to 100 mol %, more preferably 50 to 100 mol %, still
more preferably 70 to 100 mol %, further preferably 80 to 100 mol
%, particularly preferably 90 to 100 mol %, most preferably 100 mol
% in 100 mol % of all structural units (structural unit derived
from N-vinyl lactam and structural unit derived from monomer
(E)).
[0095] Here, all structural units do not include any structure
derived from a crosslinkable monomer.
[0096] In the N-vinyl lactam-based crosslinked polymer, the
proportion of the structural unit derived from a monomer (E) is
preferably 0 to 70 mol %, more preferably 0 to 50 mol %, still more
preferably 0 to 30 mol %, further preferably 0 to 20 mol %,
particularly preferably 0 to 10 mol %, most preferably 0 mol % in
100 mol % of all structural units.
[0097] The N-vinyl lactam-based crosslinked polymer may optionally
contain a structural unit derived from a crosslinkable monomer
other than the cyanuric acid structure-containing crosslinkable
monomer and/or a structural unit derived from a crosslinking agent.
The ratio of the structural unit derived from a crosslinkable
monomer and/or the structural unit derived from a crosslinking
agent to 100 mol % of all structural units is preferably 0 to 2 mol
%, more preferably 0 to 1 mol %, still more preferably 0 to 0.8 mol
%.
[0098] The crosslinked polymer of the first aspect of the invention
preferably has a water absorption capacity of 15 g or greater per 1
g of the N-vinyl lactam-based crosslinked polymer (15 times or
more). The water absorption capacity is more preferably 18 g or
greater, still more preferably 20 g or greater.
[0099] The crosslinked polymer of the first aspect of the invention
preferably has an oil absorption capacity of 3 g or greater, more
preferably 5 g or greater, still more preferably 10 g or greater,
further more preferably 15 g or greater, most preferably 20 g or
greater, per 1 g of the crosslinked polymer.
[0100] The water and oil absorption capacities are values
calculated from "(weight of crosslinked polymer+amount of solution
absorbed)/weight of crosslinked polymer". The liquid absorption
capacity of the crosslinked polymer may be determined by the method
described in the examples.
[0101] The crosslinked polymer of the first aspect of the invention
preferably has a proportion of an extractable of 18 mass % or less
in 100 mass % of the N-vinyl lactam-based crosslinked polymer.
[0102] The extractable means an uncrosslinked polymer fraction
soluble in water. The amount of the extractable is determined as
follows. The crosslinked polymer of the invention is stirred in
deionized water (conductivity: 10 pS/cm or lower) in an amount
about 100 times the amount of the crosslinked polymer for 16 hours
at room temperature (temperature: 23.+-.2.degree. C.) and
atmospheric pressure, the resulting mixture is filtered to obtain a
liquid, and the amount of the extractable in the liquid was
determined.
[0103] The N-vinyl lactam-based crosslinked polymer having a
proportion of an extractable of 18 mass % or less in 100 mass % of
the N-vinyl lactam-based crosslinked polymer has more sufficient
gel-pulverizability. In this case, kneaders are particularly
suitably used.
[0104] The N-vinyl lactam-based crosslinked polymer having a water
absorption capacity of 15 times or more and having a proportion of
an extractable of 18 mass % or less in 100 mass % of the N-vinyl
lactam-based crosslinked polymer is another aspect of the
invention. The proportion of an extractable is more preferably 17
mass % or less, still more preferably 16 mass % or less, further
more preferably 15 mass % or less.
[0105] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention preferably has an average particle size of
crosslinked polymer particles of 0.1 to 5000 .mu.m. The crosslinked
polymer particles having an average particle size of 0.1 to 5000
.mu.m tend to have a higher absorption speed for water, for
example. The crosslinked polymer particles having an average
particle size of 0.1 .mu.m or larger allow a more sufficient
reduction of an extractable in the crosslinked polymer. The
crosslinked polymer particles more preferably have an average
particle size of 0.5 to 3000 .mu.m, still more preferably 1 to 1000
.mu.m.
[0106] The average particle size of the crosslinked polymer is a
value measured using a dry particle size distribution analyzer
(Model: Mastersizer 3000, dry type, product of Malvern in Spectris
Co., Ltd.) or a particle size distribution analyzer using a laser
diffraction-scattering method that has the same principle as this
analyzer. In cases where the crosslinked polymer is in a
rectangular compact form, the average particle size is a value
measured with a ruler.
[0107] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention preferably contains particles having an
aspect ratio of 1.15 to 10 in a proportion of 10% to 100% (by
number) of the total number of the N-vinyl lactam-based crosslinked
polymer particles. The proportion of the particles having an aspect
ratio of 1.15 to 10 is preferably 30% to 100% (by number), still
more preferably 50% to 100% (by number), further preferably 70% to
100% (by number), particularly preferably 90% to 100% (by number),
most preferably 100% (by number).
[0108] The aspect ratio of the particles is preferably 1.15 to 7,
more preferably 1.15 to 5, still more preferably 1.2 to 5, further
preferably 1.2 to 3, further particularly preferably 1.25 to 3,
most preferably 1.25 to 2.5.
[0109] The aspect ratio is determined by measuring the major and
minor axes of primary particles of the cyclic N-vinyl lactam-based
cross-linked polymer with a (optical or electron) microscope and
dividing the major axis by the minor axis. In cases where the
N-vinyl lactam-based crosslinked body particles form an aggregate,
the aspect ratios of primary particles free from aggregation are
measured. In cases where the primary particles overlap each other,
the aspect ratios of particles free from overlapping are
measured.
[0110] The aspect ratio is calculated by analyzing image data of a
sample obtained from an optical or electron microscope using image
analyzing particle size distribution measurement software. The
aspect ratio may be measured with "image analyzing particle size
distribution measurement software Mac-view ver. 4 (Mountech Co.,
Ltd.)", a "particle image analysis system Morphologi G3 (product of
Malvern in Spectris Co., Ltd.)", or image analysis software or an
image analysis system which has the same principle as these.
[0111] The proportion of the particles having an aspect ratio of
1.15 to 10 can be determined by measuring the aspect ratios of
randomly selected 100 or more particles.
<Method of Producing N-Vinyl Lactam-Based Crosslinked Polymer of
the First Aspect of the Invention>
[0112] The N-vinyl lactam-based crosslinked polymer of the first
aspect of the invention may be produced by any method and is
preferably produced by polymerizing a monomer component containing
a N-vinyl lactam-based monomer and a cyanuric acid
structure-containing crosslinkable monomer. That is, a method of
producing a N-vinyl lactam-based crosslinked polymer including
polymerizing a monomer component containing a N-vinyl lactam-based
monomer and a cyanuric acid structure-containing crosslinkable
monomer is also one aspect of the invention.
[0113] Specific examples and preferred examples of the monomer
component are as described above.
[0114] The proportions of the N-vinyl lactam and the monomer (E) in
100 mol % of all monomer components (N-vinyl lactam and monomer
(E)) are the same as those of the respective structural units in
100 mol % of all structural units.
[0115] The purity of the cyclic N-vinyl lactam monomer used in the
polymerization is preferably 90% or higher, more preferably 95% or
higher, further more preferably 98% or higher, most preferably 99%
or higher.
[0116] The polymerization may be performed in the absence or
presence of a solvent. Various conventionally known methods are
available for the polymerization. Examples thereof include bulk
polymerization, solution polymerization, suspension polymerization,
inverse suspension polymerization, emulsion polymerization, inverse
emulsion polymerization, precipitation polymerization, cast
polymerization, thin-film polymerization, and spray
polymerization.
[0117] A preferred polymerization method is solution
polymerization. Solution polymerization allows prevention of uneven
crosslinking in the crosslinked polymer.
[0118] Here, stirring in the polymerization reaction may be
performed by any method. In cases where a gelled crosslinked
polymer is formed, the crosslinked polymer is preferably stirred
using a double-arm kneader as a stirring apparatus while it is
fragmented by a shear force applied by the double-arm kneader. The
polymerization may be performed in a batch wise or continuous
manner.
[0119] The polymerization of the monomer component containing a
N-vinyl lactam may be started by addition of a polymerization
initiator, UV irradiation, application of heat, or light
irradiation in the presence of a photo initiator.
[0120] In cases where the polymerization uses a solvent, examples
of the solvent include water and alcohols such as methyl alcohol,
ethyl alcohol, isopropyl alcohol, n-butyl alcohol, and diethylene
glycol. One or two or more selected from these may be used. In
terms of safety of the resulting composition, water is preferably
used as a solvent. In this case, replacement of the solvent can be
skipped, leading to an increase in productivity.
[0121] The polymerization preferably uses a polymerization
initiator to perform polymerization. Suitable examples of the
polymerization initiator include peroxides such as hydrogen
peroxide and t-butyl hydroperoxide; persulfates such as sodium
persulfate, potassium persulfate, and ammonium persulfate; azo
compounds such as dimethyl 2,2'-azobis(2-methylpropionate),
2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile),
2,2'-azobis(2-methylpropionamidine) dihydrochloride,
2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate,
2,2'-azobis[2-(2-imidazolin-2-yl)propane],
2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride,
2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate hydrate,
2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride,
2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] n-hydrate,
and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; organic
peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic
acid, di-t-butyl peroxide, and cumene hydroperoxide; and redox
initiators that generate radicals by combining an oxidizing agent
and a reducing agent, such as a combination of ascorbic acid and
hydrogen peroxide, a combination of sodium sulfoxylate and t-butyl
hydroperoxide, and a combination of a persulfate and a metal salt.
Preferred among these polymerization initiators are hydrogen
peroxide, persulfates, and azo compounds. The azo compounds are
most preferred. More preferred among these are
2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride,
2,2'-azobis[2-(2-imidazolin-2-yl)propane],
2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate hydrate,
2,2'-azobis(2-methylpropionamidine) dihydrochloride, and
2,2'-azobis(2-methylbutyronitrile). Each of these polymerization
initiators may be used alone or two or more of these may be used as
a mixture.
[0122] The polymerization initiator is preferably used in an amount
of 0.1 g or more and 10 g or less per 1 mol of the monomers (the
sum of the N-vinyl lactam, the cyanuric acid structure-containing
crosslinkable monomer, the above-described monomer (E), and the
crosslinkable monomer other than the cyanuric acid
structure-containing crosslinkable monomer). The use of 0.1 g or
more of the polymerization initiator allows a sufficient reduction
of the proportion of an unreacted monomer contained in the
resulting crosslinked polymer and allows a sufficient reduction of
the amount of unreacted monomer-derived by-products such as a
compound represented by the formula (3) below. The use of 10 g or
less of the initiator allows a sufficient reduction of the
proportion of impurities contained in the resulting crosslinked
polymer. Also, the use of such an amount of the initiator allows
prevention of discoloration of the resulting crosslinked
polymer.
[0123] That is, a method of producing a N-vinyl lactam-based
crosslinked polymer in which the polymerization uses a
polymerization initiator in an amount of 0.1 to 10 g per 1 mol of
the monomer component is also one aspect of the invention.
[0124] The amount of the polymerization initiator used is more
preferably 0.1 g or more and 7 g or less, still more preferably 0.1
g or more and 5 g or less.
[0125] In cases where the polymerization uses inverse suspension
polymerization, specific examples of a dispersant suitable for this
case include sorbitan fatty acid esters, sucrose fatty acid esters,
glycerol fatty acid esters, polyglycerol fatty acid esters,
cellulose esters such as ethyl cellulose and cellulose acetate,
cellulose ethers, and carboxyl group-containing polymers such as
.alpha.-olefin-maleic anhydride copolymers. Each of these
dispersants may be used alone, or two or more of these may be
appropriately mixed and used. Here, any hydrophobic organic solvent
may be used in inverse suspension polymerization.
[0126] The polymerization may be performed under any atmosphere and
is preferably performed under inert gas (e.g., nitrogen, argon)
atmosphere. The polymerization under inert gas atmosphere likely
provides the following effects: the grinding efficiency of the
resulting crosslinked polymer can be enhanced, the proportion of an
unreacted monomer contained in the resulting crosslinked polymer
can be reduced, and in the case of adding an organic acid to the
crosslinked polymer, the reaction time of the organic acid with the
crosslinked polymer can be shortened.
[0127] The polymerization may be performed at any temperature. The
polymerization temperature is preferably relatively low because a
crosslinked polymer with a great molecular weight can be obtained.
The polymerization temperature is more preferably 20.degree. C. to
100.degree. C. because the polymerization rate is increased. Here,
the reaction time to complete the polymerization reaction may
appropriately be set depending on factors such as the reaction
temperature, and the types (properties), combination, and amounts
of a monomer component, a polymerization initiator, and a
solvent.
[0128] A reaction vessel used for the polymerization may be made of
any material usable for the polymerization. A reaction vessel made
of stainless steel is preferred, for example. The use of such a
reaction vessel made of a heat conductive material sufficiently
proceeds the polymerization reaction, and can reduce the amount of
an unreacted monomer (e.g., unsaturated monomer having a lactam
structure) contained in the resulting crosslinked polymer.
[0129] Further, a reaction vessel made of a material that does not
elute iron, such as polypropylene, is preferably used. The use of
the reaction vessel made of such a material can reduce the iron
content of the resulting crosslinked polymer.
[0130] The crosslinked polymer of the invention may be produced by
a method including an optional step in addition to the
polymerization. The production method may optionally include, for
example, gel pulverization, drying, grinding, classification,
granulation, and/or post-crosslinking.
[0131] In cases where the crosslinked polymer is a gelled polymer
obtained by polymerization using a solvent, that is, a gelled
crosslinked polymer containing a solvent, the production method
preferably includes gel pulverization.
[0132] The gel pulverization may be performed by any method capable
of converting the gelled crosslinked polymer containing a solvent
into fine particles. For example, a pulverizing machine (e.g.,
kneader, meat chopper) may be used.
[0133] The crosslinked polymer is preferably produced by a method
including drying.
[0134] In particular, in cases where the crosslinked polymer is a
gelled polymer obtained by polymerization using a solvent, that is,
a gelled crosslinked polymer containing a solvent, the production
method preferably includes drying of the gelled crosslinked polymer
or the particulate gelled crosslinked polymer obtained through the
gel pulverization. In the first aspect of the invention, drying
means an operation to increase the solid content and is usually
performed to increase the solid content of the entire crosslinked
polymer greater than that before drying. The solid content is
preferably increased to 95 mass % or more, more preferably to 96
mass % or more in 100 mass % of the entire crosslinked polymer. The
upper limit of the solid content is preferably about 99 mass %. The
drying and polymerization may be carried out at the same time, and
both drying during polymerization and drying after polymerization
may be performed in combination. More preferably, drying is
performed using a drying apparatus after polymerization. Here, the
solid content of the crosslinked polymer is determined by the
following method.
[0135] About 1 g of the crosslinked polymer is placed in a weighing
bottle (mass: W1 (g)) having an about 5-cm diameter bottom face
(mass: W2 (g)) and is dried by allowing it to stand in a constant
temperature dryer at a temperature of 150.degree. C. for one hour.
The mass (W3 (g)) of the sum of the weighing bottle and the dried
crosslinked polymer is measured, and the solid content is
determined from the following equation:
Solid content (mass %)=((W3 (g)-W1 (g))/W2 (g)).times.100.
[0136] The drying is carried out at a temperature within the range
of 80.degree. C. to 250.degree. C. preferably for 50% or more of
the entire period of the drying, more preferably substantially
throughout the drying. Within the above range, the physical
properties of the crosslinked polymer tend to enhance.
[0137] The drying temperature is defined by the temperature of a
heat medium. In the case of using, for example, microwave, that is,
in cases where the drying temperature cannot be defined by the
temperature of a heat medium, the drying temperature is defined by
a material temperature. The drying may be performed by any method
carried out at a temperature within the above range and may
suitably be performed by hot air drying, no-wind drying,
reduced-pressure drying, infrared drying, or microwave drying, for
example. Preferred among these is hot air drying. In the hot air
drying, the drying airflow is preferably within the range of 0.01
to 10 m/sec, more preferably within the range of 0.1 to 5 m/sec.
The drying temperature is more preferably within the range of
110.degree. C. to 220.degree. C., still more preferably within the
range of 120.degree. C. to 200.degree. C. The drying may be carried
out at a fixed temperature or at varying temperatures.
Substantially, the entire drying is preferably carried out within
the above temperature ranges.
[0138] The production method preferably includes grinding. The
grinding can provide a crosslinked polymer having a more suitable
average particle size and a more suitable aspect ratio.
[0139] In the case of the production method of the invention
including drying, the grinding may be performed before, during, or
after the drying, preferably after the drying. More preferably, the
grinding is performed after the gel pulverization and the
drying.
[0140] The grinding preferably uses a grinder. Examples of the
grinder to be used include, but are not limited to, a roll grinder
such as a roll mill, a hammer grinder such as a hammer mill, an
impact grinder, a cutter mill, a turbo grinder, a ball mill, a pin
mill, a flash mill, and a jet mill such as a fluidized-bed jet mill
or a target jet mill. A target jet mill is preferably used to grind
the polymer into particles having a smaller average particle size.
The particle size distribution is preferably controlled by using a
roll mill, a hammer grinder, an impact grinder, a pin mill, or a
jet mill. The particle size distribution is preferably controlled
by performing grinding two times or more continuously, more
preferably performing grinding three times or more
continuously.
[0141] The two or more grinding operations may use the same grinder
or different grinders. Different grinders may be used in
combination.
[0142] The grinding may be performed by any grinding method and may
be performed at room temperature or by freeze grinding. The N-vinyl
lactam-based crosslinked polymer, which is soft, is preferably
ground by freeze grinding. The use of a target jet mill is capable
of more finely grinding the polymer even at room temperature.
Thereby, the production cost can be more reduced than the
production cost in the case of freeze grinding. In addition,
classification described below can be omitted by using a target jet
mill. Thereby, the productivity can be more increased.
[0143] In order to obtain the crosslinked polymer of the invention
having an average particle size within a more suitable range and/or
a specific particle size distribution, for example, the production
method may include classification or granulation. The
classification may use a sieve with a specific mesh size. Any
classifier may be used for classification using a sieve. Examples
of the classifier include, but are not limited to, a vibration
sieve (e.g., unbalanced weight-driven type, resonant type,
vibrating motor type, electromagnetic type, and circular vibration
type), an in-plane motion sieve (e.g., horizontal motion type,
horizontal circle-linear motion type, and three-dimensional circle
motion type), a movable net sieve, a compulsory stirring sieve, a
net plane vibration sieve, a wind force sieve, and a sonic sieve.
Preferred are a vibration sieve and an in-plane motion sieve.
[0144] In cases where the crosslinked polymer has a crosslinked
structure formed by any of the processes (2) to (5), the method of
producing the crosslinked polymer includes post-crosslinking of
forming the crosslinked structure after the polymerization of a
monomer component.
[0145] Examples of the method of post-crosslinking (crosslinking
after polymerization) include (i) a method of applying UV, .gamma.
rays, or an electron beam to the polymer obtained in the
polymerization, (ii) a method of self-crosslinking the polymer
obtained in the polymerization in the presence of a reaction
accelerator such as a condensing agent, (iii) a method of
self-crosslinking the polymer obtained in the polymerization by
application of heat, (iv) a method of introducing a radical
generating agent into the polymer obtained in the polymerization
and self-crosslinking the polymer by application of heat, and (v) a
method of introducing a radical polymerizable crosslinking agent
(crosslinkable monomer) and a radical polymerization initiator into
the polymer obtained in the polymerization and applying heat and/or
light to the polymer.
[0146] In cases where the crosslinked polymer of the invention has
a crosslinked structure formed by the process (2), the crosslinking
agent is preferably used in such an amount that the ratio of the
functional group of the crosslinking agent to 100 mol % of the
reactive functional group (reactive functional group reactive with
the crosslinking agent) of the polymer is 30 to 100 mol %, more
preferably 50 to 100 mol %. The use of the crosslinking agent in
such a ratio allows sufficient formation of the crosslinked
structure and can reduce the amount of an unreacted crosslinking
agent remaining in the resulting crosslinked polymer.
[0147] Examples of the reaction accelerator used in the method (ii)
include acids such as sulfuric acid and phosphoric acid; bases such
as sodium hydroxide and potassium hydroxide; and condensing agents
such as N,N'-dicyclohexyl carbodiimide. One or two or more of these
may be used.
[0148] The radical generating agent used in the method (iv) may be
the same as the polymerization initiator used in the
above-described polymerization. Preferred among the polymerization
initiators are peroxides such as hydrogen peroxide, t-butyl
hydroperoxide, t-butyl peroxypivalate, octanoyl peroxide, succinic
peroxide, t-hexyl peroxy-2-ethylhexanoate, t-butyl
peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, and t-butyl
peroxy maleic acid.
[0149] In cases where the crosslinked polymer of the invention has
a crosslinked structure formed by the process (5), the amount of
the crosslinkable monomer used in the post-crosslinking is
preferably 0.1 to 50 mass %, more preferably 1 to 30 mass %
relative to 100 mass % of the polymer before the post-crosslinking.
The use of the crosslinkable monomer in such a ratio allows
sufficient formation of the crosslinked structure and can reduce
the amount of an unreacted crosslinkable monomer remaining in the
resulting crosslinked polymer.
[0150] The production of the crosslinked polymer preferably
includes adding an organic acid to the resulting crosslinked
polymer after the polymerization reaction. The addition of an
organic acid to the resulting crosslinked polymer can reduce the
amount of the N-vinyl lactam-based monomer remaining in the
crosslinked polymer.
[0151] Examples of the organic acid include, but are not limited
to, organic compounds having an acid group such as a carboxyl
group, a sulfonic group, a phosphonic group, a sulfuric group, or a
phosphoric group. Specific examples of such organic acids include
malonic acid, oxalic acid, succinic acid, aspartic acid, citric
acid, glutamic acid, fumaric acid, malic acid, maleic acid,
phthalic acid, trimellitic acid, pyromellitic acid, propionic acid,
heptanoic acid, octanoic acid, glycolic acid, salicylic acid,
lactic acid, L-ascorbic acid, benzoic acid, methanesulfonic acid,
benzenesulfonic acid, laurylbeneznesulfonic acid, p-toluenesulfonic
acid, benzenephosphonic acid, and laurylsulfonic acid.
[0152] The organic acid may be used in any amount, and the amount
thereof is preferably 0.01 to 5 mass % relative to 100 mass % of
the N-vinyl lactam-based monomer added in the reaction step. The
use of the organic acid in an amount within the above range can
reduce the amount of the N-vinyl lactam-based monomer remaining in
the resulting polymer and can reduce the amount of the organic acid
(salt). The amount of the organic acid is more preferably 0.05 to 3
mass %, still more preferably 0.1 to 1 mass %.
[0153] The organic acid (salt) indicates the organic acid and a
salt of the organic acid. The salt of the organic acid indicates a
neutralized product of the organic acid and a base to be added in
the neutralization described below.
[0154] In the case of adding the organic acid to the crosslinked
polymer, the organic acid and the crosslinked polymer may be
reacted with each other for any period of time. The reaction time
is preferably 10 minutes to 3 hours, more preferably 30 minutes to
2 hours.
[0155] The method of producing the crosslinked polymer preferably
includes aging of the crosslinked polymer after the polymerization
reaction. The aging can reduce the amount of the residual N-vinyl
lactam-based monomer and can reduce the amount of a by-product
derived from the residual N-vinyl lactam-based monomer, such as a
compound represented by the formula (3) described below. The
temperature of the aging is preferably, but is not limited to,
70.degree. C. to 150.degree. C. At the aging temperature within the
above range, the amount of the residual N-vinyl lactam-based
monomer can be more sufficiently reduced. The aging temperature is
more preferably 80.degree. C. to 100.degree. C.
[0156] The aging time in the aging is preferably, but is not
limited to, 10 minutes to 5 hours, more preferably 30 minutes to 3
hours.
[0157] In the case of the method of producing the crosslinked
polymer including adding an organic acid, the aging is preferably
performed before adding an organic acid.
[0158] The aging is preferably performed while the crosslinked
polymer is pulverized. In the case of the method including the
adding an organic acid, the pulverization allows the organic acid
to sufficiently permeate the pulverized crosslinked polymer. Thus,
the amount of the N-vinyl lactam-based monomer remaining in the
crosslinked polymer can be more sufficiently reduced. The
crosslinked polymer may be pulverized by a common method and may be
pulverized by a method using a screw extruder such as a kneader or
a meat chopper, or a gel grinder such as a cutter mill, for
example.
[0159] In the case of adding an organic acid, the method of
producing the crosslinked polymer preferably includes
neutralization after the adding an organic acid. The neutralization
may be performed by any method and is preferably performed by
adding a base after the reaction of the organic acid with the
polymer. Examples of the base include, but are not limited to,
ammonia; aliphatic amines such as monoethanolamine, diethanolamine,
and triethanolamine; aromatic amines such as aniline; and alkali
metal hydroxides such as sodium hydroxide and potassium hydroxide.
Each of these may be used alone, or two or more of these may be
used in combination. Preferred among these are ammonia, aliphatic
amines, and alkali metal hydroxides, and more preferred are
ammonia, monoethanolamine, diethanolamine, sodium hydroxide, and
potassium hydroxide.
[0160] The N-vinyl lactam-based crosslinked polymer-containing
composition of the invention contains the N-vinyl lactam-based
crosslinked polymer, and the composition may contain any amount of
the N-vinyl lactam-based crosslinked polymer. The amount of the
N-vinyl lactam-based crosslinked polymer is preferably 50 to 100
mass %, more preferably 60 to 100 mass %, still more preferably 70
to 100 mass % relative to 100 mass % of the composition.
[0161] The N-vinyl lactam-based crosslinked polymer-containing
composition may optionally contain a different component other than
the crosslinked polymer. Examples of the different component
include, but are not limited to, an extractable (uncrosslinked
polymer fraction soluble in water), polymerization initiator
residues, residual monomers, by-products in the polymerization, and
water. The composition may contain one or two or more of these.
[0162] The N-vinyl lactam-based crosslinked polymer-containing
composition may optionally contain as a by-product of the
polymerization a compound represented by the following formula
(3):
##STR00003##
wherein R.sup.4 represents a hydrogen atom or an optionally
substituted C1-C10 alkyl group; and y represents an integer of 1 to
3. The composition preferably has a proportion of the compound of 2
mass % or less in 100 mass % of the N-vinyl lactam-based
crosslinked polymer. At a proportion of the compound represented by
the formula (3) of 2 mass % or less, odor and/or discoloration of
the composition can be sufficiently prevented. Thus, the
composition is suitable for cosmetic applications.
[0163] That is, the N-vinyl lactam-based crosslinked
polymer-containing composition having a proportion of a compound
represented by the formula (3) of 2 mass % or less in 100 mass % of
the N-vinyl lactam-based crosslinked polymer is also one aspect of
the invention. The proportion of the compound represented by the
formula (3) is more preferably 1.5 mass % or less, still more
preferably 1 mass % or less.
[0164] The proportion of the compound represented by the formula
(3) in the composition is determined by the method described in the
examples.
[0165] R.sup.4 and y in the formula (3) are the same as R.sup.4 and
y in the formula (2).
[0166] The composition having a proportion of the residual monomer
such as the N-vinyl lactam-based monomer of preferably 200 ppm or
less in 100 mass % of the N-vinyl lactam-based crosslinked polymer.
The composition having a proportion of the residual monomer within
the above range is more highly safe as a cosmetic. The proportion
of the residual monomer is more preferably 100 ppm or less, still
more preferably 50 ppm or less.
[0167] The proportion of the residual monomer in the composition
may be determined by the method described in the examples.
[0168] The N-vinyl lactam-based crosslinked polymer and/or the
N-vinyl lactam-based crosslinked polymer-containing composition of
the invention can be used in applications such as an ink absorbing
agent for use in writing instruments and ink jet recording
apparatuses, deodorants, fragrance agents, and cosmetics.
[0169] An ink absorbing agent including the N-vinyl lactam-based
crosslinked polymer or the N-vinyl lactam-based crosslinked
polymer-containing composition of the invention is also one aspect
of the invention.
[0170] The invention also relates to an ink-containing composition
including the N-vinyl lactam-based crosslinked polymer of the
invention and ink absorbed by the polymer.
[0171] The invention also relates to an ink-containing composition
including the ink absorbing agent and ink absorbed by the
agent.
[0172] The invention also relates to an absorbent material
including the ink absorbing agent.
[0173] The invention also relates to a printer including the ink
absorbing agent.
[0174] The invention also relates to a method of using the ink
absorbing agent, the ink absorbing agent being incorporated into a
printer.
[0175] The printer may be any apparatus that prints using ink
mounted in the printer. Examples of the printer include an ink-jet
printer, an offset printer, and a gravure printer.
[0176] Examples of the components of the ink include, but are not
limited to, water, water-soluble organic solvents, dyes, pigments,
and other additives.
[0177] Examples of the water-soluble organic solvents include
glycerol and glycols such as ethylene glycol and diethylene
glycol.
[0178] Examples of the dyes include black azo compounds, copper
phthalocyanine compounds, and magenta dyes.
[0179] Examples of the pigments include inorganic pigments such as
carbon black and metal oxides and organic pigments such as azo
pigments and phthalocyanine pigments. The pigments may have any
particle size, and the particle size is preferably 0.01 to 0.50
.mu.m, more preferably 0.02 to 0.20 .mu.m.
[0180] The invention also relates to a deodorant containing the
N-vinyl lactam-based crosslinked polymer or N-vinyl lactam-based
crosslinked polymer-containing composition of the invention.
[0181] The deodorant may be effective against any odor component
and is effective against, for example, thiols such as methyl
mercaptan, amines such as ammonia, carboxylic acids such as acetic
acid, aldehydes such as nonenal, and diketones such as diacetyl.
That is, the N-vinyl lactam-based crosslinked polymer of the
invention can exhibit a deodorizing effect against various odor
components. The reason for this is considered as follows. The
crosslinked polymer of the invention is capable of absorbing odor
components at a N site or a carbonyl group of the N-vinyl
lactam-derived lactam ring, and the crosslinked polymer of the
invention has moisture absorbency and thus is capable of absorbing
water-soluble odor components through moisture absorbed thereby.
The crosslinked polymer of the invention exhibits a better
deodorizing effect against carboxylic acids such as acetic acid
among the above odor components.
[0182] The deodorant may be in any form, and may be in the form of
liquid, gel, paste, powder, or solid.
[0183] The invention also relates to a deodorizer including the
deodorant.
[0184] Examples of the deodorizer include, but are not limited to,
a deodorizer including the deodorant of the invention and a vent
and a deodorizer having a mechanism that draws the deodorant of the
invention and the air.
[0185] The invention also relates to a method of using the
deodorant, the deodorant being incorporated into a deodorizer.
[0186] For example, the deodorant is used in such a way that the
air to be deodorized is brought into contact with the deodorant of
the invention.
[0187] Examples of the method of bringing the deodorant into
contact with the air include: a method in which the air is brought
into contact with the deodorant of the invention by natural
convection flow using a deodorizer including the deodorant of the
invention and a vent; and a method in which the air is drawn and
supplied to the deodorant of the invention to be brought into
contact with the deodorant of the invention using a deodorizer or
the like including the deodorant of the invention and an air
suction system.
[0188] Examples of the air suction system of the deodorizer
include, but are not limited to, a fan and an air pump.
[0189] Examples of the deodorizer including the deodorant of the
invention and an air suction system include, but are not limited
to, an air purifier and an air conditioner. In cases where the
deodorant of the invention is used in an air purifier or an air
conditioner, for example, the deodorant is preferably used in a
filter or a rotating member such as a fan.
[0190] The invention also relates to a fragrance agent containing
the N-vinyl lactam-based crosslinked polymer of the invention and a
fragrance component. Preferred examples of the fragrance component
include, but are not limited to, components with volatility, such
as perfumes and essential oils.
[0191] A cosmetic containing the N-vinyl lactam-based crosslinked
polymer of the invention and/or the N-vinyl lactam-based
crosslinked polymer-containing composition of the invention is also
one aspect of the invention.
[0192] A method of using the N-vinyl lactam-based crosslinked
polymer of the invention and/or the N-vinyl lactam-based
crosslinked polymer-containing composition of the invention as a
cosmetic is also one aspect of the invention.
[0193] The cosmetic may optionally contain a different component
other than the N-vinyl lactam-based crosslinked polymer and/or the
N-vinyl lactam-based crosslinked polymer-containing composition.
Examples of the different component include, but are not limited
to, an oily base, a moisturizing agent, a touch improving agent, a
surfactant, a polymer, a thickening agent, a gelling agent, a
solvent, a propellant, an antioxidant, a reductant, an oxidant, a
preservative, an antibacterial agent, a chelating agent, a pH
adjusting agent, an acid, an alkali, a powder, an inorganic salt,
an ultraviolet absorbent, a whitening agent, vitamins and
derivatives thereof, an antiphlogistic agent, an antiinflammatory
agent, a drug for hair growth, a blood circulation accelerator, a
stimulant, hormone, an antiwrinkle agent, an antiaging agent, a
tightening agent, a cold sense agent, a warm sense agent, a wound
healing accelerator, an irritation alleviating agent, an analgesic,
a cell activator, plant extract, animal extract, microbial extract,
an antipruritic agent, a keratin releasing and dissolving agent, an
antiperspirant, a cooling agent, an astringent, enzyme, nucleic
acid, fragrances, a coloring matter, a colorant, a dye, a pigment,
and water.
[0194] For other specific examples of the different monomer, the
components disclosed in JP 2007-45776 A may also be used.
[0195] The cosmetic of the invention may be produced by any method.
The method preferably includes, for example, mixing the crosslinked
polymer with any of the above different components.
[0196] The mixing may be performed by any technique. For example,
preferably, the crosslinked polymer in the form of a dispersion in
a solvent such as water is mixed with the different component.
[0197] The dispersion of the crosslinked polymer is preferably
treated with a wet type super atomizer ("NanoVater", Yoshida Kikai
Co., Ltd.) or a stirring and mixing apparatus ("Damatori system",
Yoshida Kikai Co., Ltd.), or a wet type super atomizer or a
stirring and mixing apparatus having the same principles as those
before mixing with the different component. Such treatment allows
sufficient disintegration of gel aggregation in the cosmetic,
leading to enhancement of the viscosity stability of the
cosmetic.
[0198] Examples of the cosmetic of the invention include, but are
not limited to, skin cosmetics, skin preparations for external use,
and hair cosmetics. The crosslinked body in the cosmetic of the
invention exerts the effects as a moisturizer, a thickening agent,
an oil-absorbing agent, or other agents in such cosmetics. The
invention also relates to a moisturizer, a thickening agent, or an
oil-absorbing agent, each containing the cyclic N-vinyl
lactam-based crosslinked body in the invention.
[0199] Examples of the skin cosmetics include, but are not limited
to, basic cosmetics such as skin lotion, cream, milky lotion, and
serum; makeup cosmetics such as liquid foundation, base milky
lotion, cheek color, eye shadow, mascara, and lipstick; cleansing
cosmetics such as cleansing cream, cleansing foam, and liquid
cleansers; cosmetics (including quasi-drugs) such as sunscreen
cosmetics; and bath cosmetics such as bath agents. Examples of skin
preparations for external use include external preparations such as
liniments, lotions, and ointments. Examples of hair cosmetics
include, but are not limited to, shampoo, rinse, conditioner, wax,
spray, gel, and mist.
[0200] The invention also relates to a skin cosmetic, a skin
preparation for external use, or a hair cosmetic, each containing
the crosslinked polymer of the invention.
<Second Aspect of the Invention: N-Vinyl Lactam-Based
Crosslinked Polymer>
[0201] The following describes the technical features of the second
aspect of the invention different from those of the first aspect of
the invention.
[0202] The N-vinyl lactam-based crosslinked polymer of the second
aspect of the invention (hereinafter, also referred to as
crosslinked polymer of the second aspect of the invention) includes
a structural unit derived from a N-vinyl lactam.
[0203] The crosslinked polymer of the second aspect of the
invention including a structural unit derived from a N-vinyl lactam
is capable of absorbing, retaining, or slowly releasing water
and/or oil. Thus, the crosslinked polymer can exert a moisturizing
effect. In addition, the crosslinked polymer capable of absorbing
oil can also exert an effect as an oil-absorbing agent. Further,
the crosslinked polymer of the invention having a crosslinked
structure swells into a gel when the polymer absorbs water or other
solvents. Therefore, the polymer exerts a thickening effect and
further enhances the adhesiveness to the skin of a cosmetic
containing the polymer.
[0204] Since the N-vinyl lactam has nonionic properties, the
crosslinked polymer of the invention including a structural unit
derived from a N-vinyl lactam is highly safe and suitable for
cosmetic applications. Further, the crosslinked polymer of the
invention including a structural unit derived from a N-vinyl lactam
has an excellent deodorizing ability for odor components. The
excellent deodorizing ability herein means a high effect of
reducing at least one of the amount and the concentration of an
odor component.
[0205] The crosslinked polymer of the second aspect of the
invention has an ethanol absorption capacity of 3 to 40 g per 1 g
of the N-vinyl lactam-based crosslinked polymer. Thus, the
crosslinked polymer is suitable for cosmetic applications. The
ethanol absorption capacity is preferably 5 g or greater, more
preferably 8 g or greater, still more preferably 10 g or greater,
still further more preferably 12 g or greater, particularly
preferably 15 g or greater, most preferably 20 g or greater.
Meanwhile, the upper limit of the ethanol absorption capacity is
preferably high, but is more preferably 35 g or less, still more
preferably 30 g or less.
[0206] The crosslinked polymer of the second aspect of the
invention has a water absorption capacity of 3 to 40 g per 1 g of
the N-vinyl lactam-based crosslinked polymer. The water absorption
capacity is preferably 5 g or greater, more preferably 8 g or
greater, still more preferably 10 g or greater, still further more
preferably 12 g or greater, particularly preferably 15 g or
greater, most preferably 20 g or greater. Meanwhile, the upper
limit of the water absorption capacity is preferably high, but is
more preferably 35 g or less, still more preferably 30 g or
less.
[0207] The crosslinked polymer of the second aspect of the
invention preferably has an oil absorption capacity of 3 g or
greater, more preferably 5 g or greater, more preferably 8 g or
greater, still more preferably 10 g or greater, still further more
preferably 12 g or greater, particularly preferably 15 g or
greater, most preferably 20 g or greater, per 1 g of the
crosslinked polymer. Meanwhile, the upper limit of the oil
absorption capacity is preferably high, but is more preferably 60 g
or less, still more preferably 50 g or less, most preferably 40 g
or less.
[0208] The ethanol, water, and oil absorption capacities are values
calculated from "(weight of crosslinked polymer+amount of solution
absorbed)/weight of crosslinked polymer". The liquid absorption
capacity of the crosslinked polymer may be determined by the method
described in the examples.
[0209] For cosmetic product applications, the N-vinyl lactam-based
crosslinked polymer of the second aspect of the invention
preferably has an average particle size of crosslinked polymer
particles of 0.1 to 100 .mu.m, more preferably 0.1 to 80 .mu.m,
still more preferably 1 to 40 .mu.m. The crosslinked polymer
particles having an average particle size of 1 to 40 .mu.m are
preferred because such polymer particles are capable of
sufficiently suppressing grainy texture on the skin to which they
are applied as a cosmetic, leading to good touch. Further, the
absorption speed for, for example, water tends to be enhanced. The
crosslinked polymer particles more preferably have an average
particle size of 1 to 30 .mu.m, still further more preferably 1 to
20 .mu.m, particularly preferably 1 to 10 .mu.m.
[0210] The average particle size of the crosslinked polymer may be
measured using a dry particle size distribution analyzer (Model:
Mastersizer 3000, dry type, product of Malvern in Spectris Co.,
Ltd.) or a particle size distribution analyzer using a laser
diffraction-scattering method that has the same principle as
this.
[0211] The N-vinyl lactam-based crosslinked polymer of the
invention contains particles having an aspect ratio determined by
the method described above of 1.15 to 10 in a proportion of 10% to
100% (by number) of the total number of the N-vinyl lactam-based
crosslinked polymer. Particles having such a shape have a larger
contact area with the skin than spherical particles and are thus
excellent in adhesiveness to the skin and easy to stay on the
surface of the skin.
[0212] The measurement method and measurement apparatus for the
aspect ratio are the same as those described for the first aspect
of the invention.
[0213] The proportion of the particles having an aspect ratio of
1.15 to 10 is preferably 30% to 100% (by number), more preferably
50% to 100% (by number), further preferably 70% to 100% (by
number), particularly preferably 90% to 100% (by number), most
preferably 100% (by number).
[0214] The aspect ratio of the particles is preferably 1.15 to 7,
more preferably 1.15 to 5, still more preferably 1.2 to 5,
particularly preferably 1.2 to 3, further particularly preferably
1.25 to 3, most preferably 1.25 to 2.5.
[0215] The average aspect ratio of randomly selected 100 or more
particles of the cyclic N-vinyl lactam-based crosslinked body is
preferably 1.15 to 5, more preferably 1.15 to 3, still more
preferably 1.2 to 3, particularly preferably 1.2 to 2.5, most
preferably 1.2 to 2.
[0216] The crosslinked structure of the crosslinked polymer of the
second aspect of the invention may include a crosslinked structure
other than the structural unit derived from a crosslinkable
monomer. The crosslinked structure can be formed by any of the
following processes (6) to (10), for example.
[0217] (6) A monomer component containing a crosslinkable monomer
is polymerized to produce a polymer having a crosslinked
structure.
[0218] (7) A monomer component containing a reactive functional
group-containing monomer is polymerized to obtain a polymer, and
the polymer is reacted with a crosslinking agent having multiple
functional groups capable of reacting with the reactive functional
group to form a crosslinked structure.
[0219] (8) A monomer component containing a monomer 1 having a
reactive functional group and a monomer 2 having a reactive
functional group capable of reacting with the reactive functional
group of the monomer 1 is polymerized, and then the reactive
functional group of the monomer 1 is reacted with the reactive
functional group of the monomer 2 to form a crosslinked structure
(self-crosslinking).
[0220] (9) Radicals are produced in polymers, and a crosslinked
structure is formed between the polymers containing radicals
(self-crosslinking).
[0221] (10) Radicals are produced in a polymer, and the polymer
containing radicals is reacted with a crosslinkable monomer to form
a crosslinked structure.
[0222] Specific examples of the crosslinkable monomer are the same
as those described for the first aspect of the invention.
[0223] The crosslinked structure of the crosslinked polymer of the
second aspect of the invention may be formed by any of the
processes (6) to (10). The crosslinked structure formed by the
process (6) is preferred.
[0224] Preferred among the crosslinkable monomers in the processes
(6) and (10) are compounds having at least two allyl groups because
the use of such compounds tends to reduce a residual N-vinyl lactam
and an extractable (uncrosslinked polymer fraction soluble in
water). Specifically, preferred are cyanuric acid
structure-containing crosslinkable monomers such as triallyl
cyanurate; pentaerythritol (di, tri, or tetra)(meth)allyl ethers,
triallyl isocyanurate, triallyl phosphate, triallylamine, diallyl
carbonate, 1,3-bis(allyloxy)-2-propanol, divinylethylene urea,
1,4-butylene bis(N-vinylamide), and (di, tri, tetra, penta, hexa,
hepta, or octa)allyl sucrose.
[0225] More preferred are triallyl cyanurate, pentaerythritol (di,
tri, or tetra)allyl ethers and (di, tri, tetra, penta, hexa, hepta,
or octa)allyl sucrose. A N-vinyl lactam-based crosslinked polymer
including a structural unit derived from triallyl cyanurate, a
pentaerythritol (di, tri, or tetra)allyl ether, or (di, tri, tetra,
penta, hexa, hepta, or octa)allyl sucrose is one preferred
embodiment of the invention. Such a crosslinked polymer is more
suitable for cosmetic applications because pentaerythritol (di,
tri, or tetra)allyl ethers and (di, tri, tetra, penta, hexa, hepta,
or octa)allyl sucrose are highly safe.
[0226] The N-vinyl lactam-based crosslinked polymer includes: a
structural unit derived from a N-vinyl lactam-based monomer; and a
structural unit derived from a crosslinkable monomer and/or a
structural unit derived from a crosslinking agent. The ratio of the
structural unit derived from a crosslinkable monomer and/or the
structural unit derived from a crosslinking agent is preferably
0.01 to 2 mol % to 100 mol % of all structural units. The
crosslinked polymer containing the structural unit derived from a
crosslinkable monomer and/or the structural unit derived from a
crosslinking agent in a ratio of 0.01 to 2 mol % has a gel strength
within a more suitable range. Thus, the crosslinked polymer has
more sufficient gel-pulverizability into particles having a smaller
average particle size. Further, the absorbent or retention capacity
for solvents such as water of the crosslinked polymer of the
invention can be controlled by controlling the ratio of the
structural unit derived from a crosslinkable monomer and/or the
structural unit derived from a crosslinking agent.
[0227] The ratio is more preferably 0.05 to 1.5 mol %, still more
preferably 0.06 to 1.4 mol %, further preferably 0.08 to 1.2 mol %,
further more preferably 0.1 to 1 mol %.
[0228] In the case of the crosslinked polymer including a
structural unit derived from a cyanuric acid structure-containing
crosslinkable monomer, the ratio of the structural unit is
preferably 0.05 to 1.5 mol %, still more preferably 0.06 to 1.4 mol
%, further preferably 0.08 to 1.2 mol %, further more preferably
0.1 to 1 mol %, still further more preferably 0.12 to 0.8 mol %,
particularly preferably 0.12 to 0.6 mol %, most preferably 0.12 to
0.48 mol %.
[0229] In the case of the N-vinyl lactam-based crosslinked polymer
including a structural unit derived from a crosslinkable monomer,
the ratio of the structural unit is preferably 0.01 to 2 mol %,
more preferably 0.1 to 1 mol % to 100 mol % of all structural
units.
[0230] The N-vinyl lactam-based crosslinked polymer of the second
aspect of the invention has a proportion of an extractable of 35
mass % or less in 100 mass % of the N-vinyl lactam-based
crosslinked polymer. The use of such a polymer in intended
applications increases the concentration of an effective component
therein. Such a crosslinked polymer used as a cosmetic has
excellent moisturizing and oil-absorbing effects, and sufficiently
allows prevention of an increase in viscosity of the cosmetic.
[0231] The proportion of the extractable is more preferably 30 mass
% or less, still more preferably 25 mass % or less.
[0232] The proportion of the extractable in the composition may be
determined by the method described in the examples.
[0233] The N-vinyl lactam-based crosslinked polymer preferably has
a viscosity of 100 mPas or higher and lower than 10000 mPas in the
form of a 5 mass % aqueous dispersion of the crosslinked polymer.
The crosslinked polymer with such a viscosity can have favorable
applicability to the skin as a cosmetic.
[0234] That is, it is also a preferred embodiment of the invention
that the N-vinyl lactam-based crosslinked polymer has a viscosity
measured under the following conditions of 100 mPas or higher and
lower than 10000 mPas.
<Viscosity Measurement Conditions>
[0235] Sample: A 5 mass % aqueous dispersion of the N-vinyl
lactam-based crosslinked polymer after 16-hour stirring
[0236] Measuring equipment: The sample is measured using a B-type
viscometer at 25.degree. C.
[0237] Measurement conditions: Rotor No. 4, rotation speed: 30
rpm
[0238] The viscosity is preferably 500 mPas or higher and lower
than 10000 mPas, more preferably 1000 mPas or higher and lower than
10000 mPas, still more preferably 3000 mPas or higher and 9000 mPas
or lower, particularly preferably 5000 mPas or higher and 9000 mPas
or lower, particularly further preferably 7000 mPas or higher and
9000 mPas or lower.
[0239] The viscosity can be determined by the following method.
<Measurement of Viscosity>
[0240] A 50-mL glass screw tube is charged with 2.5 g of a
particulate crosslinked polymer and 47.5 g of deionized water
(conductivity: 10 .mu.S/cm or lower), which are precisely weighed.
A stirrer bar is placed in the tube, and the tube is sealed. These
operations are performed in a room at a temperature of
23.+-.2.degree. C., a relative humidity of 50.+-.5%, and
atmospheric pressure. Thereafter, the contents are stirred using a
magnetic stirrer for 16 hours at room temperature (temperature:
23.+-.2.degree. C.) and atmospheric pressure to prepare a 5 mass %
aqueous dispersion of the cyclic N-vinyl lactam-based crosslinked
body. Subsequently, the temperature of the aqueous solution is set
at 25.degree. C., and the viscosity is measured using a B-type
viscometer (BM type, Toki Sangyo Co., Ltd.) (Rotor No. 4, rotation
speed: 30 rpm).
<Method of Producing N-Vinyl Lactam-Based Crosslinked Polymer of
the Second Aspect of the Invention>
[0241] The N-vinyl lactam-based crosslinked polymer of the second
aspect of the invention may be produced by any method and is
preferably produced by polymerizing a monomer component containing
a N-vinyl lactam-based monomer and forming a crosslinked structure.
That is, a method of producing a N-vinyl lactam-based crosslinked
polymer including polymerizing a monomer component containing a
N-vinyl lactam-based monomer and forming a crosslinked structure is
also one aspect of the invention.
[0242] Specific examples and preferred examples of the monomer
component are as described above. The proportion of the N-vinyl
lactam, the proportion of the monomer (E), and the ratio of the
crosslinkable monomer to 100 mol % of all monomer components
(N-vinyl lactam and monomer (E)) are the same as the proportion of
the structural unit derived from a N-vinyl lactam, the proportion
of the structural unit derived from a monomer (E), and the ratio of
the structural unit derived from a crosslinkable monomer to 100 mol
% of all structural units.
[0243] When the crosslinked structure is formed using the
crosslinkable monomer, the polymerization and the formation of the
crosslinked structure are performed at the same time. Such an
embodiment is also a preferred embodiment of the invention.
[0244] The polymerization reaction in the polymerization may be
performed at any pH and is preferably performed at a pH of 5 to 10.
The polymerization reaction at a pH within the range of 5 to 10
allows prevention of the hydrolysis of the N-vinyl lactam-based
monomer and can reduce the amount of a by-product derived from a
residual N-vinyl lactam-based monomer, such as a compound
represented by the formula (3) described above. The pH during the
polymerization reaction is more preferably 7 to 9. The pH may be
controlled by any method. Preferably, the pH of the solution of the
monomer component to be used is controlled using an acid or a base
before addition to a reaction vessel.
[0245] In cases where the crosslinked polymer of the invention has
a crosslinked structure formed by any of the processes (7) to (10),
the method of producing the crosslinked polymer includes
post-crosslinking of forming the crosslinked structure after the
polymerizing a monomer component.
[0246] The post-crosslinking may use a polymer produced from a
monomer component or a commercially available polymer.
[0247] The N-vinyl lactam-based crosslinked polymer-containing
composition of the second aspect of the invention contains the
N-vinyl lactam-based crosslinked polymer, and the amount of the
N-vinyl lactam-based crosslinked polymer in the composition and a
different component other than the crosslinked polymer are the same
as those for the N-vinyl lactam-based crosslinked
polymer-containing composition of the first aspect of the
invention.
[0248] The N-vinyl lactam-based crosslinked polymer-containing
composition preferably has a proportion of an extractable of 35
mass % or less in 100 mass % of the N-vinyl lactam-based
crosslinked polymer. With a proportion of an extractable within the
above preferred range, the concentration of an effective component
in the composition can more increase, and the composition can have
better moisturizing and oil-absorbing effects when it is used as a
cosmetic and more sufficiently allows prevention of an increase in
viscosity of a cosmetic.
[0249] That is, the N-vinyl lactam-based crosslinked
polymer-containing composition having a proportion of an
extractable of 35 mass % or less in 100 mass % of the N-vinyl
lactam-based crosslinked polymer is also one aspect of the
invention. The proportion of the extractable is more preferably 30%
or less, still more preferably 25% or less.
[0250] The proportion of the extractable in the composition may be
determined by the method described in the examples.
[0251] The N-vinyl lactam-based crosslinked polymer of the
invention also has an excellent deodorizing ability for odor
components, and thus is suitable for deodorant applications. That
is, the N-vinyl lactam-based crosslinked polymer can be suitably
used as a deodorant, and a deodorant containing the N-vinyl
lactam-based crosslinked polymer of the invention is also one
aspect of the invention.
<Third Aspect of the Invention: Cosmetic>
[0252] The following describes the technical features of the third
aspect of the invention different from those of the first and
second aspects of the invention.
[0253] The matters referring to "the third aspect of the invention"
herein are common to the first and second embodiments of the third
aspect of the invention.
[0254] The cosmetic of the third aspect of the invention contains a
cyclic N-vinyl lactam-based crosslinked polymer (hereinafter, also
referred to as crosslinked polymer in the third aspect of the
invention) including a structural unit derived from a cyclic
N-vinyl lactam.
[0255] Ionic polymers often have skin irritation and corrosiveness
and are poor in safety. On the other hand, a cyclic N-vinyl lactam
has nonionic properties and the crosslinked polymer in the third
aspect of the invention including a structural unit derived from a
cyclic N-vinyl lactam is safer than conventional additives and
suitable for cosmetic applications.
[0256] Further, the crosslinked polymer in the third aspect of the
invention including a structural unit derived from a cyclic N-vinyl
lactam is capable of absorbing, retaining, or releasing water
and/or oil. Thus, the crosslinked polymer can exert a moisturizing
effect. In addition, the crosslinked polymer capable of absorbing
oil can also exert an effect as an oil-absorbing agent. Further,
the crosslinked polymer in the invention having a crosslinked
structure swells into a gel when the polymer absorbs water or other
solvents. Therefore, the polymer exerts a thickening effect and
further enhances the adhesiveness to the skin of a cosmetic
containing the polymer.
[0257] The cyclic N-vinyl lactam-based crosslinked body in the
first embodiment of the third aspect of the invention, that is, the
cyclic N-vinyl lactam-based crosslinked polymer preferably has a
viscosity of 100 mPas or higher and lower than 10000 mPas
determined under the above conditions. The crosslinked polymer with
such a viscosity can have favorable applicability to the skin as a
cosmetic.
[0258] The viscosity is preferably 500 mPas or higher and lower
than 10000 mPas, more preferably 1000 mPas or higher and lower than
10000 mPas, still more preferably 3000 mPas or higher and 9000 mPas
or lower, particularly preferably 5000 mPas or higher and 9000 mPas
or lower, particularly further preferably 7000 mPas or higher and
9000 mPas or lower.
[0259] The cyclic N-vinyl lactam-based crosslinked polymer in the
second embodiment of the third aspect of the invention in
particulate form contains particles having an aspect ratio
determined by the method described above of 1.15 to 10 in a
proportion of 10% to 100% (by number) of the total number of the
cyclic N-vinyl lactam-based crosslinked polymer particles. The
particles having such a shape have a larger contact area with the
skin than spherical particles. Such particles are easily caught on
the surface of the skin and excellent in adhesiveness to the skin.
In cases where the cyclic N-vinyl lactam-based crosslinked polymer
particles form an aggregate, the aspect ratios of only primary
particles free from aggregation are measured. In cases where the
primary particles overlap each other, the aspect ratios of only
particles free from overlapping are measured.
[0260] The aspect ratio is calculated by analyzing image data of a
sample obtained from an optical or electron microscope using image
analyzing particle size distribution measurement software. "Image
analyzing particle size distribution measurement software Mac-view
ver. 4 (Mountech Co., Ltd.)", a "particle image analysis system
Morphologi G3 (product of Malvern in Spectris Co., Ltd.)", or image
analysis software or an image analysis system which has the same
principle as these may be available for the measurement.
[0261] The proportion of the particles having an aspect ratio of
1.15 to 10 may be determined by measuring the aspect ratios of
randomly selected 100 or more particles.
[0262] The proportion of the particles having an aspect ratio of
1.15 to 10 is preferably 30% to 100% (by number), more preferably
50% to 100% (by number), still more preferably 70% to 100% (by
number), particularly preferably 90% to 100% (by number), most
preferably 100% (by number).
[0263] The aspect ratio of the particle is preferably 1.15 to 7,
more preferably 1.15 to 5, still more preferably 1.2 to 5,
particularly preferably 1.2 to 3, further particularly preferably
1.25 to 3, most preferably 1.25 to 2.5.
[0264] The average aspect ratio of randomly selected 100 or more
particles of the cyclic N-vinyl lactam-based crosslinked polymer is
preferably 1.15 to 5, more preferably 1.15 to 3, still more
preferably 1.2 to 3, particularly preferably 1.2 to 2.5, most
preferably 1.2 to 2.
[0265] It is also a preferred embodiment of the invention that the
cyclic N-vinyl lactam-based crosslinked polymer in the first
embodiment of the third aspect of the invention includes particles
having an aspect ratio determined by the method described above of
1.15 to 10 in a proportion of 10% to 100% (by number) of the total
number of the cyclic N-vinyl lactam-based crosslinked polymer
particles.
[0266] It is also a preferred embodiment of the invention that the
cyclic N-vinyl lactam-based crosslinked polymer of the second
aspect of the invention has a viscosity determined under the
above-described conditions of 100 mPas or higher and lower than
10000 mPas.
[0267] The crosslinked polymer in the third aspect of the invention
may have any shape and is preferably in particulate form. That is,
it is a preferred embodiment of the invention that the cosmetic of
the invention contains a particulate cyclic N-vinyl lactam-based
crosslinked polymer.
[0268] The crosslinked structure of the crosslinked polymer in the
third aspect of the invention may be formed by the processes (1) to
(5) and/or the processes (6) to (10) described for the first and
second aspects of the invention, for example. The crosslinked
structure may be formed by the processes (1) to (5) and/or the
processes (6) to (10). The crosslinked structure formed by the
process(es) (1) and/or (6) is preferred.
[0269] Preferred among the crosslinkable monomers in the processes
(1), (5), (6), and (10) are compounds having at least two allyl
groups because the use of such compounds tends to reduce a residual
N-vinyl lactam and an extractable (uncrosslinked polymer fraction
soluble in water). Specifically, preferred are cyanuric acid
structure-containing crosslinkable monomers such as triallyl
cyanurate, triallyl isocyanurate, triallyl phosphate,
triallylamine, diallyl carbonate, 1,3-bis(allyloxy)-2-propanol,
pentaerythritol (di, tri, or tetra)(meth)allyl ethers, and (di,
tri, tetra, penta, hexa, hepta, or octa)allyl sucrose. More
preferred are triallyl cyanurate, pentaerythritol (di, tri, or
tetra)(meth)allyl ethers, and (di, tri, tetra, penta, hexa, hepta,
or octa)allyl sucrose.
[0270] The cyclic N-vinyl lactam-based crosslinked polymer
preferably contains a structural unit derived from a crosslinkable
monomer in a ratio of preferably 0.0001 to 10 mol %, more
preferably 0.01 to 1 mol % to 100 mol % of all structural
units.
[0271] The absorbent or retention capacity for solvents such as
water of the crosslinked body in the invention can be controlled by
controlling the amount of the crosslinkable monomer to be used.
[0272] The cyclic N-vinyl lactam-based crosslinked polymer in the
third aspect of the invention may have any average particle size.
The average particle size is preferably 0.1 to 100 .mu.m, more
preferably 0.1 to 80 .mu.m, still more preferably 0.1 to 50 .mu.m,
particularly preferably 1 to 40 .mu.m. The polymer having an
average particle size within the above ranges tends to have a
higher absorption speed for, for example, water in the invention.
Further, a cosmetic product containing such a polymer has favorable
touch.
[0273] The average particle size of the crosslinked body is a value
measured using a dry particle size distribution analyzer (Microtrac
MT3000II series, MicrotracBEL Corp.) or a particle size
distribution analyzer using a laser diffraction-scattering method
that has the same principle as this.
[0274] The crosslinked polymer in the third aspect of the invention
preferably has a water absorption capacity of 3 times or more, more
preferably 5 times or more, still more preferably 10 times or more,
particularly preferably 15 times, most preferably 20 times or
more.
[0275] The crosslinked polymer in the third aspect of the invention
preferably has an oil absorption capacity of 3 times or more, more
preferably 5 times or more, still more preferably 10 times or more,
particularly preferably 15 times or more, most preferably 20 times
or more.
[0276] The water and oil absorption capacities are values
calculated from "(weight of crosslinked polymer+amount of absorbed
solution)/weight of crosslinked polymer". The liquid absorption
capacity of the crosslinked polymer may be determined by the method
described in the examples.
<Method of Producing Cyclic N-Vinyl Lactam-Based Crosslinked
Polymer in the Third Aspect of the Invention>
[0277] The cyclic N-vinyl lactam-based crosslinked polymer
contained in the cosmetic of the invention may be produced by any
method and may be produced by polymerizing a monomer component.
Specific examples and preferred examples of the monomer component,
the crosslinking agent component, the proportion of the monomer
component, and the ratio of the crosslinking agent component are
the same as those described for the first and second aspects of the
invention.
[0278] When the crosslinked structure is formed using the
crosslinkable monomer, the polymerization and the formation of the
crosslinked structure are performed at the same time. Such an
embodiment is also a preferred embodiment of the invention.
[0279] In cases where the polymerization uses a polymerization
initiator, the preferred range of the amount of the polymerization
initiator to be used is the same as that in the second aspect of
the invention.
[0280] In cases where the production method includes grinding, the
grinding preferably uses a grinder.
[0281] Further, a jet mill is preferably used to grind the
crosslinked body into particles having an average particle size of
100 .mu.m or smaller.
[0282] The cosmetic of the invention may contain any amount of the
cyclic N-vinyl lactam-based crosslinked polymer, and the proportion
of the polymer in 100 mass % of the cosmetic is preferably 0.01 to
50 mass %, more preferably 0.05 to 30 mass %, still more preferably
0.1 to 20 mass %.
[0283] The cosmetic of the invention may contain a cyclic N-vinyl
lactam-based polymer free from a crosslinked structure (an
extractable). The proportion of the extractable in 100 mass % of
the cyclic N-vinyl lactam-based crosslinked polymer is preferably
35 mass % or less. With a proportion of an extractable within the
above preferred range, the concentration of an effective component
in the cosmetic of the invention increases, the cosmetic has better
moisturizing and oil-absorbing effects, and an increase in
viscosity of the cosmetic is sufficiently prevented. The proportion
of the extractable is more preferably 30 mass % or less, still more
preferably 25 mass % or less, most preferably 20 mass % or
less.
[0284] The proportion of the extractable in the cosmetic may be
determined by the method described in the examples.
[0285] In the cosmetic of the invention, the proportion of the
residual monomer such as the N-vinyl lactam-based monomer is
preferably 200 ppm or less in 100 mass % of the cyclic N-vinyl
lactam-based crosslinked polymer. The cosmetic of the invention
having a proportion of the residual monomer within the above range
is more highly safe. The proportion of the residual monomer is more
preferably 100 ppm or less, still more preferably 50 ppm or less,
most preferably 0 ppm.
[0286] The proportion of the residual monomer in the cosmetic may
be determined by the method described in the examples.
[0287] The cosmetic of the invention may contain a different
component other than the cyclic N-vinyl lactam-based crosslinked
body. The different component is the same as described above.
<Fourth Aspect of the Invention: Absorbent Composite>
[0288] The following describes the technical features of the fourth
aspect of the invention different from those of the first to third
aspects of the invention.
[0289] The matters referring to "the fourth aspect of the
invention" herein are common to the first and second embodiments of
the fourth aspect of the invention.
[0290] The absorbent composite of the fourth aspect of the
invention includes a nonionic crosslinked polymer and an absorbent
base material. Such a composite is suitable for applications
requiring a formed body, such as ink absorbent applications for
printers, for example.
[0291] A nonionic crosslinked polymer has a lower liquid absorption
speed than a conventional crosslinked body primarily containing a
polyacrylic acid (salt). Such a disadvantage is reduced in a
nonionic crosslinked polymer in the form of a composite with an
absorbent base material. Specifically, when the absorbent composite
absorbs liquid, the absorbent base material first absorbs liquid,
and the nonionic crosslinked polymer then absorbs the diffused
liquid. Such a composite, that is, the absorbent composite of the
fourth aspect of the invention is capable of absorbing liquid
faster than a nonionic crosslinked polymer alone.
[0292] Further, the absorbent composite of the fourth aspect of the
invention has excellent liquid absorbency, and thus is suitable for
cosmetic applications such as moisturizers.
[0293] The absorbent composite of the first embodiment of the
fourth aspect of the invention has a mass ratio of the nonionic
crosslinked polymer to the absorbent base material (nonionic
crosslinked polymer/absorbent base material) of 0.1 or more and
less than 2.
[0294] When the mass ratio of the nonionic crosslinked polymer to
the absorbent base material is 0.1 or more, the nonionic
crosslinked polymer is capable of further sufficiently receiving
liquid absorbed by the absorbent base material, leading to
sufficient prevention of leakage of liquid from the absorbent base
material. This mass ratio is more preferably 0.2 or more, still
more preferably 0.3 or more, still further more preferably 0.4 or
more, particularly preferably 0.5 or more, most preferably 0.7 or
more. The upper limit of the mass ratio is more preferably 1.9 or
less, still more preferably 1.8 or less, still further more
preferably 1.7 or less, particularly preferably 1.5 or less, most
preferably 1.3 or less.
[0295] The absorbent composite of the second embodiment of the
fourth aspect of the invention has a mass ratio of the nonionic
crosslinked polymer to the absorbent base material (nonionic
crosslinked polymer/absorbent base material) of 2.5 or more and 15
or less. When the mass ratio of the nonionic crosslinked polymer to
the absorbent base material is 2.5 or more, the nonionic
crosslinked polymer is capable of further sufficiently receiving
liquid absorbed by the absorbent base material, leading to
sufficient prevention of leakage of liquid from the absorbent base
material.
[0296] I order to achieve the above mass ratio of the nonionic
crosslinked polymer to the absorbent base material, a space is
preferably secured previously for the nonionic crosslinked polymer
to swell by liquid absorption. In addition, the absorbent base
material can be prevented from being broken by the internal
pressure and the amount of liquid absorbed by the absorbent
composite per volume thereof can be further increased by
controlling the amount of the nonionic crosslinked polymer in
consideration of swelling of the nonionic crosslinked polymer.
[0297] The mass ratio of the nonionic crosslinked polymer to the
absorbent base material (nonionic crosslinked polymer/absorbent
base material) in the second embodiment of the fourth aspect of the
invention is 15 or less. When the mass ratio is 15 or less, the
amount of the absorbent base material is further enough relative to
the nonionic crosslinked polymer, and the absorption speed of the
absorbent composite is further enhanced.
[0298] In the case of the absorbent composite having a planar shape
such as a sheet shape, the absorbent composite preferably has a
mass ratio of the nonionic crosslinked polymer to the absorbent
base material of 2.5 to 5, more preferably 3 to 5.
[0299] In the case of the absorbent composite having a flat bag
shape, the absorbent composite preferably has a mass ratio of the
nonionic crosslinked polymer to the absorbent base material of 2.5
to 7, more preferably 3 to 5.
[0300] In the case of the absorbent composite having a
three-dimensional bag shape such as a pyramid shape, the absorbent
composite preferably has a mass ratio of the nonionic crosslinked
polymer to the absorbent base material of 3 to 15, more preferably
4 or more, still more preferably 5 or more, particularly preferably
6 or more. The upper limit of the mass ratio is more preferably 13
or less, still more preferably 11 or less.
[0301] The absorbent composite preferably has a water absorption
capacity of 3 to 30 g per 1 g of the absorbent composite. The water
absorption capacity is preferably 5 g or greater, more preferably
10 g or greater, still more preferably 15 g or greater,
particularly preferably 20 g or greater.
[0302] The absorbent composite preferably has an ethanol absorption
capacity of 3 to 30 g per 1 g of the absorbent composite. Thus, the
absorbent composite is suitable for cosmetic applications. The
ethanol absorption capacity is preferably 5 g or greater, more
preferably 10 g or greater, still more preferably 15 g or greater,
particularly preferably 20 g or greater.
<Nonionic Crosslinked Polymer>
[0303] The absorbent composite of the fourth aspect of the
invention contains a nonionic crosslinked polymer (hereinafter,
also merely referred to as crosslinked polymer).
[0304] The absorbent composite of the fourth aspect of the
invention containing a nonionic crosslinked polymer is capable of
absorbing a highly concentrated organic solvent, for example. In
addition, the nonionic properties of the crosslinked polymer make
the composite highly safe.
[0305] The nonionic crosslinked polymer has a structural unit (a)
derived from a nonionic monomer (A).
[0306] The nonionic monomer (A) may be any nonionic monomer.
Examples thereof include amide monomers; unsaturated alcohols;
(poly)alkylene glycol monomers; (meth)acrylates; aromatic vinyl
monomers; alkenes; vinyl ethers; vinyl carboxylates; and vinyl
ethylene carbonates and derivatives thereof.
[0307] The nonionic crosslinked polymer preferably includes a
structural unit derived from an amide monomer and/or a structural
unit derived from a (poly)alkylene glycol monomer.
[0308] The amide monomers may be any of those having an amide
structure and an ethylenically unsaturated hydrocarbon group.
Examples thereof include monomers having a lactam structure
(hereinafter, also referred to as lactam-based monomers (N-vinyl
lactam-based monomers)); N-substituted or unsubstituted
(meth)acrylamides such as (meth)acrylamide, N-monomethyl
(meth)acrylamide, N-monoethyl (meth)acrylamide, N,N-dimethyl
(meth)acrylamide, and N-isopropylacrylamide; vinylacetamides such
as N-vinylacetamide and N-vinyl-N-methylacetamide; N-substituted or
unsubstituted vinylformamides such as N-vinylformamide and
N-vinyl-N-methylformamide; and vinyloxazolidones.
[0309] Example of the unsaturated alcohols include hydroxyethyl
(meth)acrylate, hydroxypropyl (meth)acrylate,
3-(meth)allyloxy-1,2-dihydroxypropane, (meth)allyl alcohol, and
isoprenol.
[0310] The (poly)alkylene glycol monomers may be any of those
having a (poly)alkylene glycol chain and an ethylenically
unsaturated hydrocarbon group. Examples thereof include: alkylene
oxide adducts in which an alkylene oxide is added to a hydroxy
group of the above-described unsaturated alcohols; and esters of a
(poly)alkylene glycol and an unsaturated carboxylic acid such as
(meth)acrylic acid.
[0311] The (poly)alkylene glycol monomers preferably have a
structure represented by the following formula (4):
##STR00004##
wherein R.sup.5 to R.sup.7 are the same as or different from each
other and each represent a hydrogen atom or a methyl group;
R.sup.8Os are the same as or different from each other and each
represent a C2-C18 oxyalkylene group; R.sup.9 represents a hydrogen
atom or a C1-C30 hydrocarbon group; p represents 0 to 5, q
represents 0 or 1; n represents the average number of moles of
oxyalkylene group added and represents 1 to 300.
[0312] R.sup.5 to R.sup.7 in the formula (4) are the same as or
different from each other and each represent a hydrogen atom or a
methyl group. Preferably, at least one of R.sup.5 and R.sup.6 is a
hydrogen atom.
[0313] The oxyalkylene group represented by --(R.sup.8O)-- in the
formula (4) is a C2-C18 oxyalkylene group. In cases where two or
more types of oxyalkylene groups are present, they may be added in
any form such as random addition, block addition, or alternating
addition.
[0314] The oxyalkylene group represented by --(R.sup.8O)-- is
preferably a C2-C8 oxyalkylene group, more preferably a C2-C4
oxyalkylene group.
[0315] Such an oxyalkylene group is an alkylene oxide adduct.
Examples of the alkylene oxide include ethylene oxide, propylene
oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene
oxide, and styrene oxide. Preferred are ethylene oxide, propylene
oxide, and butylene oxide, and more preferred are ethylene oxide
and propylene oxide.
[0316] In cases where the oxyalkylene group represented by
--(R.sup.8O)-- in the formula (4) includes an oxyethylene group to
which an ethylene oxide is added, the oxyethylene group is
preferably present in a proportion of 50 to 100 mol % in 100 mol %
of all oxyalkylene groups. At such a proportion of the oxyethylene
group, an increase in air entrainment is prevented, the air content
can be easily controlled, and a reduction of strength or a
reduction of freeze-thaw resistance can be prevented. The
proportion of the oxyethylene group is more preferably 60 to 100
mol %, still more preferably 70 to 100 mol %, particularly
preferably 80 to 100 mol %, most preferably 90 to 100 mol %.
[0317] R.sup.9 in the formula (4) represents a hydrogen atom or a
C1-C30 hydrocarbon group. R.sup.9 is preferably a C1-C20
hydrocarbon group or a hydrogen atom, more preferably a hydrogen
atom or a C1-C18 hydrocarbon group, still more preferably a
hydrogen atom or a C1-C12 hydrocarbon group, particularly
preferably a hydrogen atom or a C1-C8 hydrocarbon group, most
preferably a hydrogen atom or a C1-C3 hydrocarbon group.
[0318] Examples of the hydrocarbon group include linear or branched
alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl,
isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl,
hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, isooctyl,
2,3,5-trimethylhexyl, 4-ethyl-5-methyloctyl, 2-ethylhexyl,
tetradecyl, octadecyl, and icosyl groups; cyclic alkyl groups such
as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,
and cyclooctyl; aryl groups such as phenyl, benzyl, phenethyl, o-,
m- or p-tolyl, 2,3- or 2,4-xylyl, mesityl, naphthyl, anthryl,
phenanthryl, biphenylyl, benzhydryl, trityl, and pyrenyl groups.
Preferred among these are linear, branched, and cyclic alkyl
groups.
[0319] In the formula (4), p represents 0 to 5 and q represents 0
or 1. A preferred combination of p and q is a combination in which
p is 1 or 2 and q is 0 or a combination in which p is 0 and q is
1.
[0320] In the formula (4), n represents the average number of moles
of oxyalkylene group added and represents 1 to 300. The average
number of moles of oxyalkylene group added is preferably 1 to 150,
more preferably 1 to 100, still more preferably 1 to 80,
particularly preferably 1 to 50, most preferably 1 to 30.
[0321] The (meth)acrylates may be any ester of (meth)acrylic acid
and a C1-C20 alcohol. Examples thereof include methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and
cyclohexyl (meth)acrylate.
[0322] Examples of the aromatic vinyl monomers include styrene,
.alpha.-methylstyrene, vinyl toluene, indene, vinyl naphthalene,
and phenyl maleimide.
[0323] Examples of the alkenes include ethylene, propylene,
butadiene, isobutylene, and octene.
[0324] Examples of the vinyl ethers include methyl vinyl ether,
ethyl vinyl ether, and butyl vinyl ether.
[0325] Examples of the vinyl carboxylates include vinyl acetate and
vinyl propionate.
[0326] Preferred among the above-described nonionic monomers (A)
are amide monomers and (poly)alkylene glycol monomers.
[0327] That is, the nonionic crosslinked polymer in the fourth
aspect of the invention preferably includes a structural unit
derived from an amide monomer and/or a structural unit derived from
a (poly)alkylene glycol monomer, more preferably includes a
structural unit derived from an amide monomer.
[0328] The crosslinked structure of the nonionic crosslinked
polymer in the fourth aspect of the invention can be formed by the
processes (1) to (5) and/or the processes (6) to (10) described for
the first and second aspects of the invention, for example. The
crosslinked structure may be formed by any of the processes (1) to
(5) and/or the processes (6) to (10) and is preferably formed by
the process(es) (1) and/or (6).
[0329] The crosslinkable monomers in the processes (1), (5), (6),
and (10) are preferably the crosslinkable monomers described for
the third aspect of the invention.
[0330] The nonionic crosslinked polymer may include a structural
unit (e) derived from a monomer (E) other than, and in addition to,
the nonionic monomer (A) and the crosslinkable monomer. The
nonionic crosslinked polymer may contain a structural unit derived
from an ionic monomer as the monomer (E) as long as the nonionic
crosslinked polymer has nonionic properties.
[0331] Examples of the monomer (E) include (i) unsaturated
monocarboxylic acids such as acrylic acid and methacrylic acid and
salts thereof; (ii) unsaturated dicarboxylic acids such as fumaric
acid, maleic acid, methylene glutaric acid, and itaconic acid and
salts thereof (which may be either monovalent salts or divalent
salts); (iii) unsaturated sulfonic acids such as
3-allyloxy-2-hydroxypropane sulfonic acid, (meth)allylsulfonic
acid, isoprenesulfonic acid, (meth)acrylic acid-2-sulfoethyl ester,
and derivatives thereof and salts of the unsaturated sulfonic
acids; (iv) unsaturated amines such as N,N-dimethylaminoethyl
(meth)acrylate, N,N-dimethylaminoethyl (meth)acrylamide,
vinylpyridine, and vinylimidazole and salts and quaternary
compounds thereof; and (v) unsaturated anhydrides such as maleic
anhydride and itaconic anhydride.
[0332] Each of these may be used alone, or two or more of these may
be used in combination.
[0333] Examples of the salts in (i) to (iii) include metal salts,
ammonium salts, and organic amine salts. Examples of the salts in
(iv) include hydrochlorides and sulfates.
[0334] In the nonionic crosslinked polymer, the proportion of the
structural unit (a) derived from a nonionic monomer (A) is
preferably 30 to 100 mol % in 100 mol % of all structural units
(structural unit (a) derived from a nonionic monomer (A) and
structural unit derived from a monomer (E)). The proportion is more
preferably 50 to 100 mol %, still more preferably 70 to 100 mol %,
further preferably 80 to 100 mol %, particularly preferably 90 to
100 mol %, most preferably 100 mol %. Here, all structural units do
not include the structure derived from the crosslinkable
monomer.
[0335] In the nonionic crosslinked polymer having a unit derived
from an amide monomer and/or a unit derived from a (poly)alkylene
glycol monomer, the proportion of the structural unit derived from
an amide monomer and/or the structural unit derived from a
(poly)alkylene glycol monomer is preferably 30 to 100 mol %, more
preferably 50 to 100 mol %, still more preferably 70 to 100 mol %,
further preferably 80 to 100 mol %, particularly preferably 90 to
100 mol %, most preferably 100 mol % in 100 mol % of all structural
units.
[0336] In the nonionic crosslinked polymer, the proportion of the
structural unit (e) derived from a monomer (E) is preferably 0 to
70 mol %, more preferably 0 to 50 mol %, still more preferably 0 to
30 mol %, further preferably 0 to 20 mol %, particularly preferably
0 to 10 mol %, most preferably 0 mol % to 100 mol % of all
structural units.
[0337] In the nonionic crosslinked polymer, the ratio of the
structural unit derived from a crosslinkable monomer and/or the
structural unit derived from a crosslinking agent is preferably
0.01 to 2 mol %, more preferably 0.01 to 1 mol %, still more
preferably 0.05 to 1 mol %, most preferably 0.1 to 1 mol % to 100
mol % of all structural units.
[0338] The absorbent or retention capacity for solutions such as
ink of the nonionic crosslinked polymer in the fourth aspect of the
invention can be controlled by controlling the amount(s) of the
crosslinkable monomer and/or the crosslinking agent to be used.
Further, the nonionic crosslinked polymer containing the structural
unit derived from a crosslinkable monomer and/or the structural
unit derived from a crosslinking agent in a ratio of 0.01 mol % or
more is easily pulverized during its production.
[0339] The nonionic crosslinked polymer in the fourth aspect of the
invention may have any average particle size. The average particle
size is preferably 0.1 .mu.m or larger and 2000 .mu.m or smaller,
more preferably 0.1 .mu.m or larger and 1000 .mu.m or smaller,
still more preferably 1 .mu.m or larger and 1000 .mu.m or smaller,
further preferably 3 .mu.m or larger and 1000 .mu.m or smaller,
further more preferably 5 .mu.m or larger and 1000 .mu.m or
smaller, particularly preferably 10 .mu.m or larger and 1000 .mu.m
or smaller, most preferably 50 .mu.m or larger and 850 .mu.m or
smaller. The nonionic crosslinked polymer in the fourth aspect of
the invention having an average particle size within the above
preferred ranges tends to have an enhanced absorption capacity for
liquid such as water and an absorption speed within a suitable
range. The nonionic crosslinked polymer having an average particle
size of 0.1 .mu.m or larger can be sufficiently prevented from
being a clump when the nonionic crosslinked polymer absorbs liquid
such as water. In addition, when the polymer is formed on a
sheet-like absorbent base material to prepare a sheet-like
absorbent base material, falling of powder from the sheet-like
absorbent base material can be sufficiently prevented. The nonionic
crosslinked polymer having an average particle size of 2000 .mu.m
or smaller is capable of sufficiently preventing formation of a gap
between particles and a gap between particles and the absorbent
base material when the polymer is formed on a sheet-like absorbent
base material. Preferably, the nonionic crosslinked polymer has an
average particle size of 300 .mu.m or smaller and contains fine
powder with a size smaller than 100 .mu.m. In this case, the
crosslinked polymer is more likely to stick to the sheet.
[0340] In order to produce a bag-like absorbent composite, the
crosslinked polymer preferably has an average particle size of 100
to 500 .mu.m. The crosslinked polymer having an average particle
size of 100 .mu.m or larger can be sufficiently prevented from
leaking from a mesh of the bag-like absorbent base material. The
crosslinked polymer having an average particle size of 500 .mu.m or
smaller tends to have a higher absorption speed.
[0341] The average particle size of the nonionic crosslinked
polymer may be determined by the method described in the
examples.
<Method of Producing Nonionic Crosslinked Polymer>
[0342] The nonionic crosslinked polymer may be produced by any
method and may be produced by polymerizing a monomer component.
Specific examples and preferred examples of the monomer component,
the monomer component, the crosslinking agent component, and the
proportion of the monomer component, and the ratio of the
crosslinking agent are the same as those described for the first
and second aspects of the invention. Here, the term "all monomers"
in the preferred proportion or ratio to 100 mol % of all monomer
components described for the first and second aspects of the
invention is replaced with "all monomers (nonionic monomer and
monomer (E))".
[0343] In cases where the polymerization uses a polymerization
initiator, the amount of the polymerization initiator is preferably
0.1 g or greater and 10 g or less, more preferably 0.1 g or greater
and 7 g or less, still more preferably 0.1 g or greater and 5 g or
less per 1 mol of the monomers used (the total amount of the
nonionic monomer (A), the above-described monomer (E), and the
crosslinkable monomer used).
[0344] The use of 0.1 g or greater of the initiator allows a
sufficient reduction of the proportion of an unreacted monomer
contained in the resulting crosslinked polymer. The use of 10 g or
less of the initiator allows a sufficient reduction of the
proportion of impurities contained in the resulting crosslinked
polymer. Also, the use of such a proportion of the initiator allows
prevention of discoloration of the resulting crosslinked
polymer.
[0345] In cases where the production method includes grinding, the
particle size distribution is more preferably controlled using a
roll mill, a hammer grinder, an impact grinder, a pin mill, or a
jet mill.
[0346] A jet mill is preferably used to grind the nonionic
crosslinked polymer into particles having an average particle size
of 100 .mu.m or smaller.
[0347] In the case of the nonionic crosslinked polymer in the
invention having a crosslinked structure formed by the process(es)
(5) and/or (10), the amount of the crosslinkable monomer used in
the post-crosslinking is preferably 0.1 to 50 mass %, more
preferably 1 to 30 mass % relative to 100 mass % of the polymer
before the post-crosslinking. The use of the crosslinkable monomer
in such a ratio allows sufficient formation of the crosslinked
structure. Thus, the crosslinked polymer is capable of more
sufficiently absorbing a pigment contained in ink, and the amount
of an unreacted crosslinkable monomer remaining in the resulting
crosslinked polymer can be reduced.
[0348] In cases where the production method includes aging, the
aging is preferably performed while the nonionic crosslinked
polymer is pulverized. In the production method including adding an
organic acid, the pulverization allows the organic acid to
sufficiently permeate the pulverized crosslinked polymer. Thus, the
amount of the N-vinyl lactam-based monomer remaining in the
resulting polymer can be more sufficiently reduced. The polymer may
be pulverized by a common method. For example, the pulverization is
performed by a method using a screw extruder such as a kneader or a
meat chopper, or a gel grinder such as a cutter mill.
[0349] When the method of producing the nonionic crosslinked
polymer includes addition of an organic acid and the
below-described bag-like absorbent composite is produced as the
absorbent composite of the invention, the method preferably
includes neutralization after the addition of an organic acid.
[0350] When the nonionic crosslinked polymer is swollen by water
and bonded to a base material to produce the sheet-like absorbent
composite described below, the method preferably includes no
neutralization because the crosslinked polymer is less likely to
stick to the sheet in the presence of an organic acid salt.
Further, the production of such a sheet-like absorbent composite
needs neither the addition nor the neutralization of the organic
acid.
<Absorbent Composite>
[0351] The absorbent composite of the invention may have any shape.
Examples of the shape include a planar shape such as a sheet shape
or a flake shape, and a three-dimensional shape such as a rod shape
(cylindrical or quadrangular prism), a spherical shape, a pyramidal
shape (a triangular pyramid or a quadrangular pyramid), a conical
shape, or a massive shape.
[0352] The term "sheet" herein means a shape having a planar spread
generally recognized as a sheet. The shape preferably satisfies
that [a.sup.(1/2)]/b is 5 or more, where "a" represents the area of
the surface having the largest area in the shape and "b" represents
the length in the direction perpendicular to the surface (the
thickness of the shape). When the thickness of the shape is not
uniform, the maximum value of the thickness is defined as "b".
[0353] The absorbent composite of the invention preferably has a
sheet shape or a pyramidal shape.
[0354] In the case of the absorbent composite having a planar shape
such as a sheet shape, the absorbent base material and the nonionic
crosslinked polymer have a large area to be in contact with liquid
to be absorbed. Thus, the absorbent base material instantaneously
absorbs the liquid, and the nonionic crosslinked polymer strongly
receives the liquid from the absorbent base material and holds it.
Thus, the liquid absorption speed of the entire sheet is further
enhanced, and the liquid is sufficiently diffused throughout the
sheet.
[0355] In addition, in the case of the absorbent composite having a
sheet shape, the thickness of the absorbent composite containing
liquid absorbed is less changed. Thus, such an absorbent composite
is suitable for applications in which the thickness is
specified.
[0356] In the case of the absorbent composite having a
three-dimensional shape such as a conical shape or a pyramidal
shape, the composite is preferably a packaged body in which the
nonionic crosslinked polymer is packaged with a sheet-like
absorbent base material or packed and sealed in a bag-like
absorbent base material. The absorbent composite having such a
shape easily secures a space for the nonionic crosslinked polymer
to swell by liquid absorption. Thus, the absorbent base material
can be prevented from being broken by the internal pressure and the
liquid absorption amount per volume of the absorbent composite can
be increased by controlling the amount of the nonionic crosslinked
polymer in consideration of the swelling of the nonionic
crosslinked polymer.
[0357] The volume of the nonionic crosslinked polymer after
swelling depends on its swelling ratio. Thus, the amount of the
nonionic crosslinked polymer in the packaged body depends on the
types of the crosslinked polymer and the liquid to be absorbed. The
volume of the nonionic crosslinked polymer before liquid absorption
is preferably 2% to 35%, more preferably 3% to 20% of the volume of
the nonionic crosslinked polymer after swelling in the packaged
body taken as 100%.
[0358] In the absorbent composite of the invention, the nonionic
crosslinked polymer is preferably supported on an absorbent base
material.
[0359] The nonionic crosslinked polymer may be supported on an
absorbent base material by any method. Examples thereof include a
method of immersing an absorbent base material in a solution
containing the nonionic crosslinked polymer, a method of supporting
the nonionic crosslinked polymer on an absorbent base material
using a bonding agent, a method of mixing an absorbent base
material with the nonionic crosslinked polymer, a method of
bringing the nonionic crosslinked polymer into close contact with a
base material, and a method of packaging the nonionic crosslinked
polymer with a sheet-like absorbent base material or packed and
sealed in a bag-like absorbent base material (e.g., a method of
forming a packaged body). Here, the packaged body means a form in
which powder (nonionic crosslinked polymer) is packaged with an
absorbent base material so as not to leak therefrom.
[0360] In the method of immersing the absorbent base material in a
solution containing the nonionic crosslinked polymer, the solution
may contain a different component other than the nonionic
crosslinked polymer. Examples of the different component include a
polymer prepared by polymerizing a monomer such as (meth)acrylic
acid or (meth)acrylate and a solvent such as water or methanol.
[0361] In the method of supporting the nonionic crosslinked polymer
on an absorbent base material using a bonding agent, the bonding
agent may contain any component. Examples of the bonding agent
component include synthetic rubber such as styrene-butadiene rubber
or chloroprene rubber; an organic solvent such as n-pentane,
acetone, or toluene; gas such as LPG or dimethyl ether; and
adhesive resin (binder) such as polyvinylpyrrolidone.
[0362] Specific examples of the method of supporting the nonionic
crosslinked polymer on an absorbent base material using a bonding
agent include, but are not limited to, spraying on the surface of a
base material surface a dispersion in which the bonding agent and
the nonionic crosslinked polymer are dispersed in a dispersion
medium such as an organic solvent or water; applying the dispersion
with a brush or a roller; and impregnating an absorbent base
material with the dispersion. Alternatively, a method may be used
in which a solution or dispersion containing a bonding agent is
sprayed on or applied to an absorbent base material surface, the
nonionic crosslinked polymer is then uniformly sprinkled on the
surface, and the solution or dispersion is again sprayed thereon or
applied thereto. The dispersion or the like applied to the base
material may be dried as needed. Thus, the nonionic crosslinked
polymer is bonded to the absorbent base material surface (outer
surface and/or inner surface) via the bonding agent. That is, a
layer of the nonionic crosslinked polymer is formed. In the case of
forming a resin layer containing the nonionic crosslinked polymer
on an absorbent base material surface, the above method does not
need dispersing the nonionic crosslinked polymer and/or sprinkling
the nonionic crosslinked polymer.
[0363] The absorbent base material may be mixed with the nonionic
crosslinked polymer by any method. Examples of the method include
mixing ground wood pulp with the nonionic crosslinked polymer,
kneading a mixture containing the nonionic crosslinked polymer and
elastomer such as chloroprene rubber and rolling the kneaded
mixture, binding the nonionic crosslinked polymer with, for
example, an adhesive resin, and dispersing the nonionic crosslinked
polymer during the formation of a nonwoven fabric.
[0364] The nonionic crosslinked polymer may be bonded to the
absorbent base material by any method. Examples of the method
include a method including allowing the nonionic crosslinked
polymer and/or the absorbent base material absorb water, bringing
the crosslinked polymer into contact with the absorbent base
material, and dehydrating and drying them; and a method of thermal
fusion bonding or pressure bonding absorbent base materials with a
thermoplastic resin or adhesive such as polypropylene or
polyethylene and the nonionic crosslinked polymer held therebetween
using a thermal roll.
[0365] In the case of the absorbent composite having a planar shape
such as a sheet shape, it may be formed of one absorbent layer
including an absorbent base material and the nonionic crosslinked
polymer or may be formed of two or more layers stacked to each
other.
[0366] For example, the absorbent composite may have a structure in
which a nonionic crosslinked polymer-supported sheet and a sheet
not supporting the polymer are alternately stacked or a structure
in which multiple sheets supporting the nonionic crosslinked
polymer are arranged in amounts in ascending order, sheets
supporting a smaller amount of the nonionic crosslinked polymer are
arranged in the upper portion.
[0367] Alternatively, the absorbent composite may have a multilayer
structure in which two or more nonwoven fabrics different in
material (e.g., PP (polypropylene), PE (polyethylene), cellulose,
polyamide, nylon, and polyester) each having the nonionic
crosslinked polymer fixed thereon are stacked.
[0368] In the case of the absorbent composite having a planar shape
such as a sheet shape, the absorbent composite preferably has a
thickness of 0.01 to 50 mm, more preferably 0.01 to 30 mm, still
more preferably 0.01 to 20 mm, particularly preferably 0.05 to 10
mm, most preferably 0.1 to 5 mm.
[0369] The absorbent composite preferably has a weight per unit
area of 0.1 to 3000 g/m.sup.2, more preferably 0.5 to 2500
g/m.sup.2, still more preferably 1 to 1500 g/m.sup.2.
<Absorbent Base Material>
[0370] The absorbent base material may be any material that
supports the nonionic crosslinked polymer. Examples thereof include
paper, fabric, wood, elastomer, resin foam, and porous base
materials.
[0371] The paper is one defined in JIS P 0001, and the fabric is a
collective term of sheet-like fiber products defined in JIS L
0206.
[0372] The paper is preferably an adhesive paper such as a heat
sealable paper.
[0373] The basis weight of the paper is preferably, but not limited
to, 15 to 100 g/m.sup.2.
[0374] Examples of the fabric include woven fabric, knitted fabric,
braided fabric, lace, mesh, and nonwoven fabric. Preferred are
woven fabric, knitted fabric, and nonwoven fabric, and more
preferred is nonwoven fabric.
[0375] Examples of the resin foam and porous base materials
include, but are not limited to, polyurethane foam, polystyrene
foam, and inorganic porous bodies.
[0376] Examples of a fiber material forming the absorbent base
material include, but are not limited to, hydrophobic fibers such
as polyester and polypropylene; cellulosic fibers; polyamide
fibers; hydrophilic fibers such as animal fibers (e.g., silk and
wool); and hydrophobic fibers having a hydrophilic surface
layer.
[0377] The hydrophilic fiber indicates a fiber having an official
moisture regain of 3% or higher.
[0378] The official moisture regain of the fiber may be measured
according to the method described in JIS L 0105.
[0379] The absorbent base material preferably contains a
hydrophilic fiber. The hydrophilic fiber is preferably at least one
selected from the group consisting of cellulose fibers, polyamide
fibers, animal fibers, and hydrophobic fibers having a hydrophilic
surface layer.
[0380] In cases where hydrophilic fiber, which has high diffusivity
of liquid, is contained as the absorbent base material, the
nonionic crosslinked polymer further rapidly receives liquid
absorbed by the absorbent base material. Thus, the absorption speed
of the entire absorbent composite is enhanced.
[0381] The absorbent base material more preferably contains a
cellulose fiber.
[0382] Examples of the cellulose fiber include natural fibers such
as cotton and hemp; recycled fibers such as rayon, cupra, lyocell,
and polynosic fibers; semisynthetic fibers such as acetate and
triacetate; and pulp.
[0383] The absorbent base material may have any shape capable of
forming a composite with the nonionic crosslinked polymer. The
absorbent base material preferably has a sheet shape or a bag
shape.
[0384] The absorbent composite of the invention is capable of
absorbing water, a water-soluble organic solvent, or ink, for
example.
[0385] Examples of the water-soluble organic solvent include
alcohols and glycols such as glycerol, ethylene glycol, diethylene
glycol, triethylene glycol, propylene glycol, and dipropylene
glycol; amide solvents such as N,N-dimethylformamide and
N,N-dimethylacetamide; pyrrolidones such as 2-pyrrolidone and
N-methyl-2-pyrrolidone; 2-oxazolidone;
1,3-dimethyl-2-imidazolidinone; 1,1,3,3-tetramethyl urea; dimethyl
sulfoxide; and sulfolanes.
[0386] The water-soluble organic solvent is preferably glycerol, a
glycol, an alcohol, or a pyrrolidone.
[0387] The ink may contain the same component as the ink component
for the first aspect of the invention.
[0388] The invention also relates to an ink absorber including the
absorbent composite of the invention.
[0389] The invention also relates to an absorbent material
including the ink absorber.
[0390] The invention also relates to an ink-absorbed body including
the ink absorber and ink absorbed by the ink absorber.
[0391] The invention also relates to a printer including the ink
absorber.
[0392] The invention also relates to a method of using the ink
absorber, the ink absorber being incorporated into a printer.
[0393] Here, the ink absorber means one before absorbing ink, and
the ink-absorbed body means one containing ink absorbed.
[0394] The invention also relates to a cosmetic containing the
absorbent composite of the invention.
[0395] The invention also relates to a method of using the
absorbent composite of the invention as a cosmetic.
[0396] The invention also relates to a deodorant containing the
absorbent composite of the invention.
[0397] The invention also relates to a deodorizer including the
deodorant.
[0398] The invention also relates to a method of using the
deodorant, the deodorant being incorporated into a deodorizer.
<Fifth Aspect of the Invention: Ink Absorbing Agent>
[0399] The following describes the technical features of the fifth
aspect of the invention different from those of the first to fourth
aspects of the invention.
[0400] The ink absorbing agent of the fifth aspect of the invention
contains a N-vinyl lactam-based crosslinked polymer (cyclic N-vinyl
lactam-based crosslinked polymer) (hereinafter, also referred to as
crosslinked polymer of the invention) including a structural unit
derived from a N-vinyl lactam.
[0401] The ink absorbing agent of the fifth aspect of the invention
that contains the crosslinked polymer of the invention including a
structural unit derived from a cyclic N-vinyl lactam is capable of
sufficiently absorbing ink, leading to a sufficient reduction of
residual ink liquid.
[0402] Conventional ink absorbing agents such as polyacrylic
acid-based liquid absorbent resins and polyethylene oxide
crosslinked polymers are capable of absorbing an organic solvent as
a water-rich aqueous solution. However, when the water evaporates
and the organic solvent component in the solution absorbed by the
ink absorbing agents is concentrated, the polymer cannot hold the
liquid any longer, causing liquid leakage (discharge).
[0403] On the other hand, the ink absorbing agent of the invention
is capable of absorbing a highly concentrated organic solvent and
is also capable of retaining the organic solvent absorbed, leading
to sufficient prevention of leakage of liquid.
[0404] The crosslinked structure of the crosslinked polymer in the
invention may be formed by the processes (1) to (5) and/or the
processes (6) to (10) described for the first and second aspects of
the invention. The preferred embodiments of the crosslinked
structure formed by the processes (1) to (5) and/or the processes
(6) to (10) are the same as those for the first and second aspects
of the invention, for example. Specific examples of the
crosslinkable monomer are the same as those described for the first
and second aspects of the invention. The crosslinked structure may
be formed by the processes (1) to (5) and/or the processes (6) to
(10) and is preferably formed by the process(es) (1) and/or
(6).
[0405] The crosslinkable monomers in the processes (1), (5), (6),
and (10) are preferably the crosslinkable monomers described for
the first and second aspects of the invention.
[0406] In the N-vinyl lactam-based crosslinked polymer, the ratio
of the structural unit derived from a crosslinkable monomer and/or
the structural unit derived from a crosslinking agent is preferably
0.01 to 2 mol %, more preferably 0.01 to 1 mol %, still more
preferably 0.05 to 1 mol %, most preferably 0.1 to 1 mol % relative
to 100 mol % of all the structural units.
[0407] The absorbent or retention capacity for ink of the
crosslinked polymer in the invention can be controlled by
controlling the amount(s) of the crosslinkable monomer and/or
crosslinking agent to be used. Further, the crosslinked polymer
containing the structural unit derived from a crosslinkable monomer
and/or the structural unit derived from a crosslinking agent in a
ratio of 0.01 mol % or more is easily pulverized during its
production.
[0408] The crosslinked polymer of the invention may have any
average particle size. The average particle size is preferably 0.1
.mu.m or larger and 2000 .mu.m or smaller, more preferably 0.1
.mu.m or larger and 1000 .mu.m or smaller, further preferably 1
.mu.m or larger and 1000 .mu.m or smaller, further more preferably
3 .mu.m or larger and 1000 .mu.m or smaller, still more preferably
5 .mu.m or larger and 1000 .mu.m or smaller, particularly
preferably 10 .mu.m or larger and 1000 .mu.m or smaller, most
preferably 50 .mu.m or larger and 850 .mu.m or smaller. The
crosslinked polymer having an average particle size within the
above preferred ranges tends to have an enhanced absorption
capacity for liquid such as water and an absorption speed within a
suitable range. The crosslinked polymer having an average particle
size of 0.1 .mu.m or larger can be sufficiently prevented from
being a clump when the crosslinked polymer absorbs liquid such as
water. In addition, when the polymer is formed into an ink
absorbent sheet, falling of powder from the sheet base material can
be sufficiently prevented.
[0409] The average particle size of the crosslinked polymer may be
determined by the method described in the examples.
[0410] The crosslinked polymer in the invention has an excellent
ink absorption capacity. For example, the crosslinked polymer
preferably has an ink absorption capacity of 5 times or more, more
preferably 10 times or more, still more preferably 15 times or
more, further more preferably 20 times or more, measured using a
pigment ink BK (BCI-350 (PGBK), Canon Inc.).
[0411] The crosslinked polymer in the invention also has an
excellent organic solvent absorption capacity. For example, the
crosslinked polymer preferably has an ethylene glycol absorption
capacity of 5 times or more, more preferably 10 times or more,
still more preferably 15 times or more.
[0412] The ink and organic solvent absorption capacities of the
crosslinked polymer may be determined by the method described in
the examples.
[0413] The crosslinked polymer in the invention may take any period
of time to absorb deionized water (conductivity: 10 .mu.S/cm or
lower) in an amount of 15 times the weight of the polymer itself
(liquid absorption capacity: 15 times), and preferably takes 0.1 to
1500 minutes, more preferably 0.3 to 600 minutes, further more
preferably 0.5 to 300 minutes, most preferably 1 to 60 minutes.
[0414] Further, the crosslinked polymer in the invention may take
any period of time to absorb propylene glycol in an amount of 4
times the weight of the polymer itself (liquid absorption capacity:
4 times), and preferably takes 0.1 to 1500 minutes, more preferably
0.3 to 600 minutes, further more preferably 0.5 to 300 minutes,
most preferably 1 to 60 minutes. Here, the propylene glycol
absorption speed was measured according to the method described in
the examples.
<Method of Producing Cyclic N-Vinyl Lactam-Based Crosslinked
Polymer in the Fifth Aspect of the Invention>
[0415] The cyclic N-vinyl lactam-based crosslinked polymer
contained in the ink absorbing agent of the invention may be
produced by any method, and may be produced by polymerizing a
monomer component. Specific examples and preferred examples of the
monomer component are the same as those described above. The
proportion of the cyclic N-vinyl lactam, the proportion of the
monomer (E), and the ratio of the crosslinkable monomer to 100 mol
% of all monomer components (cyclic N-vinyl lactam and monomer (E))
are the same as the proportion of the structural unit derived from
a cyclic N-vinyl lactam, the proportion of the structural unit
derived from a monomer (E), and the ratio of the structural unit
derived from a crosslinkable monomer to 100 mol % of all structural
units, respectively, as described above.
[0416] In cases where the polymerization uses a polymerization
initiator, the preferred range of the amount of the polymerization
initiator to be used is the same as that in the first aspect of the
invention.
[0417] In cases where the production method includes grinding, a
hammer grinder, an impact grinder, a pin mill, or a jet mill is
preferably used to control the particle size distribution.
[0418] Further, a jet mill is preferably used to grind the
crosslinked polymer into particles having an average particle size
of 100 .mu.m or smaller.
[0419] The invention also relates to an absorbent material
including the ink absorbing agent of the invention.
[0420] The absorbent material may have any shape suitable for use.
Examples thereof include a sheet shape, a rod shape (cylindrical or
quadrangular prism), a spherical shape, a pyramidal shape, a
conical shape, a flake shape, and a massive shape. Preferred are a
sheet shape and a rod shape.
[0421] When the ink absorbing agent of the invention is used in an
ink jet recording apparatus, for example, the absorbent material
including the ink absorbing agent is capable of sufficiently
preventing leakage of powder of the ink absorbing agent in the
recording apparatus. This allows sufficient prevention of failure
such as clogging of an ink jet nozzle, for example.
[0422] The absorbent material preferably includes a base material
and an ink absorbing agent. More preferably, the ink absorbing
agent is supported on the base material.
[0423] The base material of the absorbent material may be any
material commonly used. Since the ink absorbing agent of the
invention has an excellent ink retention capacity, the absorbent
material has an excellent ink retention capacity regardless of the
ink retention capacity of the base material itself. Thus, leakage
of liquid can be sufficiently prevented even when the absorbent
material is inclined.
[0424] Examples of the base material include those described for
the fourth aspect of the invention.
[0425] The absorbent agent may include a different ink absorbing
agent other than the ink absorbing agent of the invention. The
different ink absorbing agent may be any agent capable of absorbing
ink. Examples thereof include acid group-containing superabsorbent
resins, inorganic absorbent powders (e.g., powdered zeolite,
powdered clays), and powders having a structure similar to an
organic dye or an organic pigment (e.g., phthalocyanine structure,
porphyrin structure). A mixture of at least one of these ink
absorbing agents and the ink absorbing agent of the invention may
be supported on a base material.
[0426] The ink absorbing agent of the invention may be supported on
a base material by any method. Examples of the method include a
method of immersing a base material in a resin solution containing
the ink absorbing agent, a method of supporting the ink absorbing
agent on a base material using a bonding agent, a method of mixing
a base material with the ink absorbing agent, a method of thermal
fusion bonding or pressure bonding the ink absorbing agent to a
base material, a method of packaging the ink absorbing agent with a
base material and sealing it (e.g., a method of forming a packaged
body). Here, the packaged body means a form in which powder (ink
absorbing agent) is packaged with a base material so as not to leak
therefrom.
[0427] In the method of immersing the base material in a resin
solution containing the ink absorbing agent, the resin solution may
contain a different component other than the ink absorbing agent.
Examples of the different component include polymers prepared by
polymerizing a monomer such as (meth)acrylic acid or
(meth)acrylate; and solvents such as methanol.
[0428] The bonding agent component in the method of supporting the
ink absorbing agent on a base material using a bonding agent, the
method of supporting the ink absorbing agent on a base material
using a bonding agent, and the method of mixing a base material
with the ink absorbing agent are the same as those described for
the fourth aspect of the invention.
[0429] The ink absorbing agent may be thermally fusion bonded to a
base material by any method. An example of the method is one in
which a thermoplastic resin or adhesive such as polypropylene or
polyethylene and the ink absorbing agent are held between base
materials, and they are thermally fusion bonded or pressure bonded
using a thermal roll.
[0430] The ink absorbing agent may be packaged with and sealed in a
base material by any method. The ink absorbing agent is preferably
distributed in partitioned small sections in order to prevent
uneven distribution of the ink absorbing agent when the absorbent
material is inclined.
[0431] In the absorbent material, the ratio of the ink absorbing
agent of the invention to 100 mass % of the base material is
preferably 10 to 20000 mass %, more preferably 20 to 10000 mass %,
still more preferably 30 to 500 mass %, further more preferably 30
to 200 mass %, particularly preferably 30 to 180 mass %.
[0432] The absorbent material is preferably in the form of a sheet
or a packaged body.
[0433] The term "sheet" herein means a shape having a planar spread
generally recognized as a sheet. The shape preferably satisfies
that [a.sup.(1/2)]/b is 5 or more, where "a" represents the area of
the surface having the largest area in the shape and "b" represents
the length in the direction perpendicular to the surface (the
thickness of the shape). When the thickness of the shape is not
uniform, the maximum value of the thickness is defined as "b".
[0434] In cases where the ink absorbing agent is supported on a
sheet-like base material, the base material and the ink absorbing
agent have a large area to be in contact with ink. Thus, the base
material instantaneously absorbs the ink, and the ink absorbing
agent strongly receives the ink from the base material and holds
it. Thus, the ink absorption speed of the entire sheet is further
enhanced, and the ink is sufficiently diffused throughout the
sheet.
[0435] The absorbent material in the form of a packaged body means
a form in which powder (ink absorbing agent) is packaged with a
planar or three-dimensional bag-like base material so as not to
leak therefrom. The material of the base material and the
embodiment of the packaging method are not limited as long as they
hold 80% by weight or more of the ink absorbing agent without
leakage. The amount of the ink absorbing agent to be packaged is
preferably such that the volume of the ink absorbing agent
containing ink absorbed is equal to or less than the volume of the
packaged body.
[0436] Examples of the base material of the absorbent material in
the form of a packaged body include those described above.
Preferred among these is a fiber material. The size of mesh (mesh
size) of the fiber material is preferably not greater than the
particle size corresponding to R=80% in the average particle size
measurement described in the examples of the ink absorbing agent of
the invention. The fiber material having such a mesh size is
capable of sufficiently preventing leakage of the ink absorbing
agent.
[0437] The absorbent sheet may be formed of one absorbent layer
including a base material and the ink absorbing agent or may be
formed of two or more absorbent layers stacked to each other.
[0438] For example, the absorbent sheet may have a structure in
which an ink absorbing agent-supported sheet and a sheet not
supporting the ink absorbing agent are alternately stacked or a
structure in which multiple sheets supporting the ink absorbing
agent are arranged in amounts in ascending order, sheets supporting
a smaller amount of the nonionic crosslinked polymer are arranged
in the upper portion, for example.
[0439] Alternatively, the absorbent sheet may have a multilayer
structure in which two or more nonwoven fabrics different in
material (e.g., PP (polypropylene), PE (polyethylene), cellulose,
polyamide, nylon, and polyester) each having the nonionic
crosslinked polymer fixed thereon are stacked.
[0440] The absorbent sheet preferably has a thickness of 0.01 to 50
mm, more preferably 0.01 to 30 mm, still more preferably 0.01 to 20
mm, particularly preferably 0.05 to 10 mm, most preferably 0.1 to 5
mm.
[0441] The absorbent sheet preferably has a weight per unit area of
0.1 to 3000 g/m.sup.2, more preferably 0.5 to 2500 g/m.sup.2, still
more preferably 1 to 1500 g/m.sup.2.
[0442] The invention also relates to an ink-containing composition
including the ink absorbing agent of the invention and ink absorbed
by the agent.
[0443] Examples of the ink component include, but are not limited
to, water, water-soluble organic solvents, dyes, pigments, and
other additives.
EXAMPLE
[0444] The invention is described in more detail below with
reference to, but not limited to, examples. Unless otherwise
specified, "part(s)" means "part(s) by weight" and "%" means "% by
mass".
<Evaluation of Liquid Absorption Capacities of Absorbent
Composite for Solvent (Including Deionized Water) and
Solution>
[0445] An absorbent composite was weighed in a room at a
temperature of 23.+-.2.degree. C., a relative humidity of 50.+-.5%,
and atmospheric pressure (W4 (g)) and put into a container and
immersed in a solution (in the case of deionized water, it has a
conductivity of 10 .mu.S/cm or lower) at room temperature
(temperature: 23.+-.2.degree. C.) and atmospheric pressure for 24
hours. In the case of using liquid that is slowly absorbed, such as
oil, the absorbent composite was immersed therein at 40.degree. C.
for 24 hours and then cooled for 10 minutes. Subsequently, the
absorbent composite was taken out by pinching the end of the tea
bag with tweezers, placed one face down on KIMTOWEL (Nippon Paper
Crecia Co., Ltd.), and allowed to stand for five seconds. Then, the
absorbent composite was placed the other face down on KIMTOWEL and
allowed to stand for five seconds so that the liquid was removed.
Then, the mass of the absorbent composite (W5 (g)) was weighed. The
liquid absorption rate was determined according to the following
equation as the liquid absorption capacity.
Liquid absorption rate (g/g)=W5 (g)/W4 (g)
[0446] The nonionic crosslinked polymer in the absorbent composite
was evaluated in the following way.
<Evaluation of Liquid Absorption Capacities of Polymer for
Solvent (Including Deionized Water) and Solution>
[0447] About 0.1 g of a crosslinked polymer was precisely weighed
(mass: W7 (g)) and put into a 4 cm.times.5 cm nonwoven fabric tea
bag, and the tea bag was heat-sealed. These operations were
performed in a room at a temperature of 23.+-.2.degree. C., a
relative humidity of 50.+-.5%, and atmospheric pressure. The tea
bag was placed in a 50-mL (specified volume) glass screw tube and
immersed in a solvent or a solution (in the case of deionized
water, it has a conductivity of 10 .mu.S/cm or lower) for 24 hours
at room temperature (temperature: 23.+-.2.degree. C.) and
atmospheric pressure. In the case of using liquid that is slowly
absorbed, such as oil, the tea bag was immersed therein at
40.degree. C. for 24 hours and then cooled for 10 minutes.
Subsequently, the tea bag was taken out by pinching the end of the
tea bag with tweezers, placed one face down on KIMTOWEL (Nippon
Paper Crecia Co., Ltd.), and allowed to stand for five seconds.
Subsequently, the tea bag was placed the other face down on
KIMTOWEL and allowed to stand for five seconds so that the liquid
was removed. Then, the mass of the tea bag (W8 (g)) was measured.
Separately, the same operations were performed without a
crosslinked polymer. Then, the mass of the tea bag (W6 (g)) was
measured as a blank. The liquid absorption rate was determined
according to the following equation as the liquid absorption
capacity.
Liquid absorption rate (g/g)(W8 (g)-W6 (g))/W7 (g)
<Testing for Deodorizing Properties of Diacetyl>
[0448] A glass lidded Petri dish (inner diameter: 27 mm) was
prepared, and 0.50 g of the crosslinked polymer was put therein.
Separately, an empty Petri dish was prepared as a blank.
[0449] These Petri dishes were covered and completely enclosed in
sampling bags with a stopcock (Tedlar bag, GL Sciences Inc.,
volume: 3 L, shape: AAK) by heat-sealing. The sampling bags were
evacuated, and 2 L of nitrogen gas was introduced into each bag,
followed by introducing 5 mL of diacetyl-containing nitrogen gas
thereinto using a gas-tight syringe. The Petri dishes with a lid
removed were allowed to stand for two hours in the respective bags.
Then, a 100-mL portion of the gas was drawn three times from each
bag with a gas sampler (Model: GV-100S, Gastec Corporation), and
the reduction rates of diacetyl concentrations were compared using
a gas detector tube (No. 92 for acetaldehyde, Gastec Corporation).
The measured values were converted to diacetyl concentrations using
a conversion scale described in the manual of the detector
tube.
[0450] The reduction rates of diacetyl were calculated using the
following equation.
Reduction rate (%)=(gas concentration of blank-gas concentration of
sample)/(gas concentration of blank).times.100
<Testing for Deodorizing Properties for Acetic Acid>
[0451] A glass lidded Petri dish (inner diameter: 27 mm) was
prepared, and 0.50 g of the crosslinked polymer was put therein.
Separately, an empty Petri dish was prepared as a blank.
[0452] These Petri dishes were covered and completely enclosed in
sampling bags with a stopcock (Tedlar bag, GL Sciences Inc.,
volume: 3 L, shape: AAK) by heat-sealing. The sampling bags were
evacuated, and 2 L of nitrogen gas was introduced into each bag.
Thereafter, 5 mL of acetic acid-containing air was introduced into
each bag using a gas-tight syringe. The Petri dishes with a lid
removed were allowed to stand for two hours in the respective bags.
Then, a 100-mL portion of the gas was drawn once from each bag with
a gas sampler (Model: GV-100S, Gastec Corporation), and the
concentrations of acetic acid were measured using a gas detector
tube (No. 81 for acetic acid, Gastec Corporation). The reduction
rates were calculated based on the actual value measured with the
detector tube.
[0453] The reduction rates of acetic acid were calculated using the
following equation.
Reduction rate (%)=(gas concentration of blank-gas concentration of
sample)/(gas concentration of blank).times.100
<Measurement of Aspect Ratio>
[0454] The aspect ratio was determined by measuring the major and
minor axes of a cyclic N-vinyl lactam-based crosslinked polymer
particle with an optical microscope and dividing the major axis by
the minor axis. The aspect ratio was calculated by analyzing image
data of a sample obtained from an optical microscope using
"particle image analysis system, Morphologi G3 (product of Malvern
in Spectris Co., Ltd.)". The aspect ratios of any 100 or more
particles were measured, and the average value of the aspect ratios
was determined. Further, in the particles sorted in ascending order
of the aspect ratio, the aspect ratio of the particle at 10% by
number of all particles, the aspect ratio of the particle at 50% by
number of all particles, and the aspect ratio of the particle at
90% by number of all particles were calculated.
[0455] In addition to the above described system, the aspect ratio
may be measured by analyzing image data of a sample obtained from
an optical or electron microscope using "image analyzing particle
size distribution measurement software, Mac-view, ver. 4 (Mountech
Co., Ltd.)".
<Quantification of Residual Monomer (N-Vinyl Lactam-Based
Monomer) and by-Product (Compound Represented by the Formula
(3))>
[0456] A 110-mL screw tube was charged with about 1 g of a
particulate crosslinked polymer (mass: W9 (g)) and about 100 g of
deionized water (mass: W10 (g)) (conductivity: 10 .mu.S/cm or
lower), which were precisely weighed. A stirrer bar was placed in
the tube, and the tube was sealed. These operations were performed
in a room at a temperature of 23.+-.2.degree. C., a relative
humidity of 50.+-.5%, and atmospheric pressure. Thereafter, the
contents were stirred using a magnetic stirrer at room temperature
(temperature: 23.+-.2.degree. C.) and atmospheric pressure for 16
hours or longer (rotation speed: 600 rpm). These operations
extracted the residual monomer of the particulate crosslinked
polymer (N-vinyl lactam-based monomer) and a by-product (compound
represented by the formula (3)). The resulting extract solution was
quantitatively analyzed by liquid chromatography under the
following conditions.
Apparatus: "NANOSPACE SI-2", Shiseido Company, Limited
Column: "CAPCELLPAK C18 UG120" (20.degree. C.), Shiseido Company,
Limited
[0457] Eluent: Methanol for LC (Wako Pure Chemical Industries,
Ltd.)/super pure water=1/24 (mass ratio) supplemented with 0.04
mass % of sodium 1-heptanesulfonate Flow rate: 100 .mu.L/min
Content (ppm)=measured value (ppm).times.(W9 (g)+W10 (g))/W9
(g)
<Measurement of Extractable>
[0458] A 110-mL glass screw tube was charged with about 1 g of a
particulate crosslinked polymer (mass: W11 (g)) and about 100 g of
deionized water (mass: W12 (g)) (conductivity: 10 .mu.S/cm or
lower), which were precisely weighed. A stirrer bar was placed in
the tube, and the tube was sealed. These operations were performed
in a room at a temperature of 23.+-.2.degree. C., a relative
humidity of 50.+-.5%, and atmospheric pressure. Thereafter, the
contents were stirred using a magnetic stirrer at room temperature
(temperature: 23.+-.2.degree. C.) and atmospheric pressure for 16
hours or longer (rotation speed: 600 rpm). The resulting mixture
was filtered through a qualitative filter paper (Model: No. 2,
Advantec). Thus, an extract solution of an extractable was
obtained.
[0459] Next, about 10 g of the extract solution (mass: W14 (g)) was
put into an aluminum cup (mass: W13 (g)) having an about 5 cm
diameter bottom face. The solution was allowed to stand in a dryer
having a constant temperature of 120.degree. C. for two hours, and
thereby dried. After the drying, the sum of the mass (W15 (g)) of
the aluminum cup and the mass of the extractable was measured, and
the amount of the extractable was determined using the following
equation.
Amount of extractable (mass %)=((W15 (g)-W13 (g))/(W14
(g).times.W11 (g)/W12 (g))).times.100
<Measurement of Average Particle Size>
[0460] The 50% cumulative value was determined as an average
particle size using a dry particle size distribution analyzer
(Model: Mastersizer 3000, dry system, product of Malvern in
Spectris Co., Ltd.). The following describes the measurement
conditions.
<Measurement Conditions>
[0461] Dry laser diffraction scattering method Dispersion pressure:
1 bar Particle refractive index: 1.52 Particle absorptivity: 0.01
Particle shape: Non-spherical Medium name: Air Measurement range:
0.1 to 3500 .mu.m
<Measurement of Viscosity>
[0462] A 50-mL glass screw tube was charged with 2.5 g of a
particulate crosslinked polymer and 47.5 g of deionized water
(conductivity: 10 .mu.S/cm or lower), which were precisely weighed.
A stirrer bar was placed in the tube, and the tube was sealed.
These operations were performed in a room at a temperature of
23.+-.2.degree. C., a relative humidity of 50.+-.5%, and
atmospheric pressure. Thereafter, the contents were stirred using a
magnetic stirrer at room temperature (temperature: 23.+-.2.degree.
C.) and atmospheric pressure for 16 hours to prepare a 5 mass %
aqueous dispersion of the cyclic N-vinyl lactam-based crosslinked
polymer. Subsequently, the temperature of the aqueous solution was
set at 25.degree. C., and the viscosity was measured using a B-type
viscometer (BM type, Toki Sangyo Co., Ltd.) (Rotor No. 4, rotation
speed: 30 rpm).
Production Example 1
[0463] A desktop kneader (Model: PNV-1H, Chuorika Co., Ltd.) was
charged with 130.0 parts of N-vinylpyrrolidone (hereinafter, also
referred to as VP, Nippon Shokubai Co., Ltd.), 0.52 parts (0.18 mol
% relative to VP) of triallyl cyanurate (hereinafter, also referred
to as CTA) as a crosslinking agent, and 304.6 parts of deionized
water. Subsequently, the kneader was purged with nitrogen at 100
mL/min for 30 minutes. Then, nitrogen was introduced at 30 mL/min,
and the temperature was increased to 56.degree. C. After the
temperature of the liquid was stabilized at 56.degree. C., 1.96
parts (0.25 g per 1 mol of the sum of VP and CTA used) of a 15 mass
% aqueous solution of 2,2'-azobis[2-(2-imidazolin-2-yl) propane]
dihydrochloride (hereinafter, also referred to as "VA-044") as an
initiator was added to start polymerization. A gel formed by the
polymerization reaction was aged at 90.degree. C. for 60 minutes
while it was pulverized with the rotating blade of the kneader to
complete the polymerization. Subsequently, 65.0 parts of a 1 mass %
aqueous solution of malonic acid was added over three minutes,
followed by stirring at 90.degree. C. for 60 minutes. In addition,
32.5 parts of a 2 mass % aqueous solution of diethanolamine was
added over three minutes, followed by stirring for 30 minutes. The
resulting gel was dried at 120.degree. C. for two hours (precision
constant temperature oven, Model: DF42, Yamato Scientific Co.,
Ltd., maximum opening degree, two stainless steel vats each having
external dimensions of 232.times.297.times.50 H (mm) were used) to
obtain a dried VP crosslinked polymer. Then, the crosslinked
polymer was ground using a grinder and classified using JIS
standard 250 .mu.m-mesh and 500 .mu.m-mesh sieves. The powder that
passed through the 500 .mu.m-mesh sieve and left on the 250
.mu.m-mesh sieve was obtained as a particulate VP crosslinked
polymer (VP crosslinked polymer (1) of the invention). The average
particle size of the VP crosslinked polymer (1) was 448 .mu.m
determined by the above-described method. The absorption capacities
measured by the above-described method were as follows: the
deionized water absorption capacity was 22 times, the ethanol
absorption capacity was 21 times, the linoleic acid absorption
capacity was 31 times, the ethylene glycol absorption capacity was
22 times, the propylene glycol absorption capacity was 25 times,
the pigment BK ink absorption capacity was 22 times, the dye BK ink
absorption capacity was 21 times, the dye ink C absorption capacity
was 23 times, the dye Y absorption capacity was 20 times, and the
dye M absorption capacity was 23 times. Only the linoleic acid was
measured at 40.degree. C., and the solutions other than the
linoleic acid were measured at room temperature. BCI-351 (dyes BK,
C, M, and Y) and BCI-350 (PGBK (pigment BK)) (Canon Inc.) were used
as ink.
Production Example 2
[0464] The same steps as in Production Example 1 were performed
from the start to aging at 90.degree. C. for 60 minutes to complete
the polymerization. The resulting gel was dried at 120.degree. C.
for two hours (precision constant temperature oven, Model: DF42,
Yamato Scientific Co., Ltd., maximum opening degree, two stainless
steel vats each having external dimensions of
232.times.297.times.50 H (mm) were used) to obtain a dried VP
crosslinked polymer. Then, the crosslinked polymer was ground using
a grinder and classified using a JIS standard 250 .mu.m-mesh sieve.
The powder that passed through the 250 .mu.m-mesh sieve was
obtained as a particulate VP crosslinked polymer (VP crosslinked
polymer (2) of the invention). The average particle size of the VP
crosslinked polymer (2) was 121 .mu.m determined by the
above-described method.
Production Example 3
[0465] The same steps as in Production Example 1 were performed
from the start to aging at 90.degree. C. for 60 minutes to complete
the polymerization. Subsequently, 65.0 parts of a 1 mass % aqueous
solution of malonic acid was added over three minutes, followed by
stirring at 90.degree. C. for 60 minutes. The resulting gel was
dried at 120.degree. C. for two hours (precision constant
temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum
opening degree, two stainless steel vats each having external
dimensions of 232.times.297.times.50 H (mm) were used) to obtain a
dried VP crosslinked polymer. Then, the crosslinked polymer was
ground using a grinder and classified using a JIS standard 250
.mu.m-mesh sieve. The powder that passed through the 250 .mu.m-mesh
sieve was obtained as a particulate VP crosslinked polymer (VP
crosslinked polymer (3) of the invention). The average particle
size of the VP crosslinked polymer (3) was 110 .mu.m determined by
the above-described method.
Production Example 4
[0466] A desktop kneader (Model: PNV-5H, Chuorika Co., Ltd.) was
charged with 1000.0 parts of VP, 15.0 parts (0.65 mol % relative to
VP) of pentaerythritol triallyl ether (trade name: neoallyl P-30M,
Daiso Co., Ltd., the pH was adjusted to 6 or higher using
diethanolamine) as a crosslinkable monomer, and 2368.33 parts of
deionized water. The kneader was purged with nitrogen at 400 mL/min
for 40 minutes. Then, nitrogen was introduced at 30 mL/min, and the
temperature was increased to 56.degree. C. After the temperature of
the liquid was stabilized at 56.degree. C., 47.37 parts (0.78 g per
1 mol of the sum of VP and pentaerythritol triallyl ether used) of
a 15 mass % aqueous solution of 2,2'-azobis
(2-methylpropionamidine) dihydrochloride (hereinafter, also
referred to as "V-50") as an initiator was added to start
polymerization. A gel formed by the polymerization reaction was
aged at 90.degree. C. for 60 minutes while it was pulverized with
the rotating blade of the kneader to complete the polymerization.
Subsequently, 500.0 parts of a 1.4 mass % aqueous solution of
malonic acid was added over three minutes, followed by stirring at
90.degree. C. for 60 minutes. In addition, 250.0 parts of a 2.8
mass % aqueous solution of diethanolamine was added over three
minutes, followed by stirring for 30 minutes. The resulting gel was
dried at 120.degree. C. for three hours (precision constant
temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum
opening degree, two stainless steel vats each having external
dimensions of 232.times.297.times.50 H (mm) were used, eight
stainless steel vats each having external dimensions of
206.times.267.times.40 H (mm) were used) to obtain a dried VP
crosslinked polymer. Then, the crosslinked polymer was ground using
a grinder and classified using JIS standard 250 .mu.m-mesh and 500
.mu.m-mesh sieves. The powder that passed through the 500
.mu.m-mesh sieve and left on the 250 .mu.m-mesh sieve was obtained
as a particulate VP crosslinked polymer (VP crosslinked polymer (4)
of the invention). The average particle size of the VP crosslinked
polymer (4) was 393 .mu.m determined by the above-described method.
The absorption capacities measured by the above-described method
were as follows: the deionized water absorption capacity was 22
times, the ethanol absorption capacity was 19 times, the linoleic
acid absorption capacity was 31 times, the ethylene glycol
absorption capacity was 22 times, and the propylene glycol
absorption capacity was 25 times. Only the linoleic acid was
measured at 40.degree. C., and the solutions other than the
linoleic acid were measured at room temperature.
Production Example 5
[0467] The same steps as in Production Example 4 were performed
from the start to aging at 90.degree. C. for 60 minutes to complete
the polymerization. The resulting gel was dried at 120.degree. C.
for two hours (precision constant temperature oven, Model: DF42,
Yamato Scientific Co., Ltd., maximum opening degree, two stainless
steel vats each having external dimensions of
232.times.297.times.50 H (mm) were used, eight stainless steel vats
each having external dimensions of 206.times.267.times.40 H (mm)
were used) to obtain a dried VP crosslinked polymer. Then, the
crosslinked polymer was ground using a grinder and classified using
a JIS standard 250 .mu.m-mesh sieve. The powder that passed through
the 250 .mu.m-mesh sieve was obtained as a particulate VP
crosslinked polymer (VP crosslinked polymer (5) of the invention).
The average particle size of the VP crosslinked polymer (5) was 93
.mu.m determined by the above-described method.
Production Example 6
[0468] The same steps as in Production Example 4 were performed
from the start to aging at 90.degree. C. for 60 minutes to complete
the polymerization. Subsequently, 500.0 parts of a 1.4 mass %
aqueous solution of malonic acid was added over three minutes,
followed by stirring at 90.degree. C. for 60 minutes. The resulting
gel was dried at 120.degree. C. for two hours (precision constant
temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum
opening degree, two stainless steel vats each having external
dimensions of 232.times.297.times.50 H (mm) were used, eight
stainless steel vats each having external dimensions of
206.times.267.times.40 H (mm) were used) to obtain a dried VP
crosslinked polymer. Then, the crosslinked polymer was ground using
a grinder and classified using a JIS standard 250 .mu.m-mesh sieve.
The powder that passed through the 250 .mu.m-mesh sieve was
obtained as a particulate VP crosslinked polymer (VP crosslinked
polymer (6) of the invention). The average particle size of the VP
crosslinked polymer (6) was 87 .mu.m determined by the
above-described method.
Production Example 7
[0469] A 250-mL PP container was charged with 27 g of
methoxypolyethylene glycol acrylate (NK ester AM-90G, Shin-Nakamura
Chemical Co., Ltd., number of moles of EO added: 9 mol,
hereinafter, also referred to as AM-90G), 3 g of 2-hydroxyethyl
acrylate containing 0.2 mass % of ethylene glycol diacrylate
(Nippon Shokubai Co., Ltd.) (hereinafter, also referred to as HEA)
as an impurity, and 70 g of pure water. Subsequently, stirring of
the contents was started with a magnetic stirrer, and the container
was purged with nitrogen at 100 mL/min for 30 minutes. The
temperature was then increased to 40.degree. C. under stirring.
After the temperature of the liquid was stabilized at 40.degree.
C., 0.1 g of a 20 mass % aqueous solution of V-50 as an initiator
was added to start polymerization. A gel formed by the
polymerization reaction was aged at 90.degree. C. for 30 minutes to
complete the polymerization. The gel was pulverized using a desktop
kneader (Model: PNV-1H, Chuorika Co., Ltd.) and then dried at
120.degree. C. for two hours (precision constant temperature oven,
Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree,
one stainless steel vat having external dimensions of
206.times.267.times.40 H (mm) was used) to obtain a PEG
acrylate/HEA crosslinked polymer (polyethylene oxide crosslinked
polymer (7)). The deionized water absorption capacity was 15 times
and the ethanol absorption capacity was 6 times, which were
determined by the above-described method at room temperature.
Comparative Production Example 1
[0470] A 250-mL polypropylene container was charged with 30.0 parts
of acrylic acid (Nippon Shokubai Co., Ltd., 80 mass % aqueous
solution) (hereinafter, also referred to as AA), 12.14 parts of
sodium hydroxide (48 mass % aqueous solution), 0.021 parts (0.01
mol % relative to AA) of polyethylene glycol dimethacrylate (NK
ester A-400, Shin-Nakamura Chemical Co., Ltd., number of moles of
EO added: 9 mol) (hereinafter, also referred to as A-400) as a
crosslinkable monomer, and 42.2 parts of deionized water (AA and
sodium hydroxide were mixed before addition of A-400 and deionized
water). Subsequently, stirring of the contents was started with a
magnetic stirrer, and the container was purged with nitrogen at 100
mL/min for 30 minutes. Then, nitrogen was introduced at 30 mL/min,
and 0.33 parts (0.12 g per 1 mol of the sum of AA and A-400 used)
of a 15 mass % aqueous solution of sodium persulfate as an
initiator and 0.04 parts of a 0.5 mass % aqueous solution of
L-ascorbic acid was added to start polymerization under stirring. A
gel formed by the polymerization reaction was aged at 90.degree. C.
for 30 minutes to complete the polymerization. The gel was
pulverized using a desktop kneader (Model: PNV-1H, Chuorika Co.,
Ltd.) and then dried at 120.degree. C. for two hours (precision
constant temperature oven, Model: DF42, Yamato Scientific Co.,
Ltd., maximum opening degree, one stainless steel vat having
external dimensions of 206.times.267.times.40 H (mm) was used) to
obtain a dried AA-based crosslinked polymer (comparative
crosslinked polymer (1)). The crosslinked polymer was ground using
a grinder. Thus, a particulate comparative crosslinked polymer (1)
was obtained. The average particle size of the comparative
crosslinked polymer (1) was 52.1 .mu.m, determined by the
above-described method. The absorption capacities measured by the
above-described method were as follows: the ethanol absorption
capacity was 1 time, the linoleic acid absorption capacity was 1
time, the ethylene glycol absorption capacity was 1 time, the
propylene glycol absorption capacity was 1 time, the pigment BK ink
absorption capacity was 20 times, the dye BK ink absorption
capacity was 16 times, the dye ink C absorption capacity was 25
times, the dye Y absorption capacity was 22 times, and the dye M
absorption capacity was 22 times. Only the linoleic acid was
measured at 40.degree. C., and the solutions other than the
linoleic acid were measured at room temperature. BCI-351 (dyes BK,
C, M, and Y) and BCI-350 (PGBK (pigment BK)) (Canon Inc.) were used
as ink.
Example 1
[0471] A sheet-like absorbent composite (1) was prepared in the
following way as Example 1 using the VP crosslinked polymer (5)
obtained in Production Example 5.
[0472] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The VP crosslinked polymer (5)
in an amount of 0.05 g was uniformly diffused on one of the two
non-woven fabrics (non-woven fabric A). Separately, water was
diffused on the other non-woven fabric (non-woven fabric B). The
non-woven fabric B was placed on the non-woven fabric A on which
the VP crosslinked polymer (5) was diffused, and they were
press-bonded. Thereafter, the resulting specimen was dried with a
dryer at 150.degree. C. for 60 minutes to obtain a sheet-like
absorbent composite (1). The amount of the VP crosslinked polymer
(5) deposited on the non-woven fabric was 6 g/m.sup.2, and the
ratio of VP crosslinked polymer/non-woven fabric base material
(mass ratio) was 0.1.
Example 2
[0473] A sheet-like absorbent composite (2) was prepared in the
following way as Example 2 using the VP crosslinked polymer (6)
obtained in Production Example 6.
[0474] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The VP crosslinked polymer (6)
in an amount of 0.3 g was uniformly diffused on one of the two
non-woven fabrics (non-woven fabric A). Separately, water was
diffused on the other non-woven fabric (non-woven fabric B). The
non-woven fabric B was placed on the non-woven fabric A on which
the VP crosslinked polymer (6) was diffused, and they were
press-bonded. Thereafter, the resulting specimen was dried with a
dryer at 150.degree. C. for 30 minutes to obtain a sheet-like
absorbent composite (2). In the absorbent composite (2), a resin
layer was formed between the two non-woven fabrics. The amount of
the VP crosslinked polymer (6) deposited on the non-woven fabric
was 54 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven
fabric base material (mass ratio) was 0.4.
Example 3
[0475] A sheet-like absorbent composite (3) was prepared in the
following way as Example 3 using the VP crosslinked polymer (3)
obtained in Production Example 3.
[0476] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The VP crosslinked polymer (3)
in an amount of 0.5 g was uniformly diffused on one of the two
non-woven fabrics (non-woven fabric A). Subsequently, water was
diffused with an atomizer on the VP crosslinked polymer. The other
non-woven fabric (non-woven fabric B) was placed on the resulting
non-woven fabric A, and they were press-bonded. Thereafter, the
resulting specimen was press-bonded and dried with an iron to
obtain a sheet-like absorbent composite (3). In the absorbent
composite (3), a resin layer was formed between the two non-woven
fabrics. The amount of the VP crosslinked polymer (3) deposited on
the non-woven fabric was 90 g/m.sup.2, and the ratio of VP
crosslinked polymer/non-woven fabric base material (mass ratio) was
0.7.
Example 4
[0477] A sheet-like absorbent composite (4) was prepared in the
following way as Example 4 using the VP crosslinked polymer (2)
obtained in Production Example 2.
[0478] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. A VP crosslinked polymer gel
swollen with water (gel prepared by adding 2.7 g of ion-exchange
water to 0.3 g of the VP crosslinked polymer (2)) was uniformly
applied to one of the two non-woven fabrics (non-woven fabric A).
Similarly to this, a VP crosslinked polymer gel swollen with water
was applied to the other non-woven fabric (non-woven fabric B).
Subsequently, the non-woven fabric A and the non-woven fabric B
were stacked so that the gel-side faces thereof faced each other,
and they were press-bonded. Thereafter, the resulting specimen was
dried with a dryer at 150.degree. C. for 60 minutes to obtain a
sheet-like absorbent composite (4). In the absorbent composite (4),
a resin layer was formed between the two non-woven fabrics. The
amount of the VP crosslinked polymer (2) deposited on the non-woven
fabric was 110 g/m.sup.2, and the ratio of VP crosslinked
polymer/non-woven fabric base material (mass ratio) was 0.9.
Example 5
[0479] A sheet-like absorbent composite (5) was prepared in the
following way as Example 5 using the VP crosslinked polymer (2)
obtained in Production Example 2.
[0480] Two pulp non-woven fabrics (Lylex paper waste, material:
pulp) each with a size of 100 mm.times.50 mm were prepared. The VP
crosslinked polymer (2) in an amount of 0.5 g was uniformly
diffused on one of the two non-woven fabrics (non-woven fabric A).
Separately, water was diffused on the other non-woven fabric
(non-woven fabric B). The non-woven fabric B was placed on the
non-woven fabric A on which the VP crosslinked polymer (2) was
diffused, and they were press-bonded. Thereafter, the resulting
specimen was dried with a dryer at 150.degree. C. for 60 minutes to
obtain a sheet-like absorbent composite (5). In the absorbent
composite (5), a resin layer was formed between the two non-woven
fabrics. The amount of the VP crosslinked polymer (2) deposited on
the non-woven fabric was 100 g/m.sup.2, and the ratio of VP
crosslinked polymer/non-woven fabric base material (mass ratio) was
1.1.
Example 6
[0481] A sheet-like absorbent composite (6) was prepared in the
following way as Example 6 using the VP crosslinked polymer (3)
obtained in Production Example 3.
[0482] Two polyester non-woven fabrics each with a size of 100
mm.times.50 mm were prepared. The VP crosslinked polymer (3) in an
amount of 0.5 g was uniformly diffused on one of the two non-woven
fabrics (non-woven fabric A). Separately, water was diffused on the
other non-woven fabric (non-woven fabric B). The non-woven fabric B
was placed on the non-woven fabric A on which the VP crosslinked
polymer (3) was diffused, and they were press-bonded. Thereafter,
the resulting specimen was dried with a dryer at 150.degree. C. for
60 minutes to obtain a sheet-like absorbent composite (6). In the
absorbent composite (6), a resin layer was formed between the two
non-woven fabrics. The amount of the VP crosslinked polymer (3)
deposited on the non-woven fabric was 78 g/m.sup.2, and the ratio
of VP crosslinked polymer/non-woven fabric base material (mass
ratio) was 0.6.
Example 7
[0483] A sheet-like absorbent composite (7) was prepared in the
following way as Example 7 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0484] A synthetic rubber bonding agent (trade name: "3M Spray
Adhesive 99", Sumitomo 3M Limited.) was used. The bonding agent
contained as components 10% by weight of synthetic rubber such as
styrene-butadiene rubber, 40% by weight of an organic solvent such
as n-pentane, acetone, or toluene, and 50% by weight of gas (for
spray use) such as LPG or dimethyl ether.
[0485] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The bonding agent was
uniformly spray-diffused on one surface of one of the two non-woven
fabrics (non-woven fabric A) so that 0.17 g of the synthetic rubber
(solid content) was deposited, followed by uniform diffusion of 0.5
g of the VP crosslinked polymer (1) thereon. Separately, the
bonding agent was uniformly spray-diffused on the other non-woven
fabric (non-woven fabric B) so that 0.17 g of the synthetic rubber
was deposited. The non-woven fabric B was placed on the non-woven
fabric A, and they were press-bonded. Thereafter, the resulting
specimen was dried with a dryer at 100.degree. C. for 10 minutes to
obtain a sheet-like absorbent composite (7). In the absorbent
composite (7), a resin layer was formed between the two non-woven
fabrics. The amount of the VP crosslinked polymer (1) deposited on
the non-woven fabric was 100 g/m.sup.2, and the ratio of VP
crosslinked polymer/non-woven fabric base material (mass ratio) was
0.8.
Example 8
[0486] A sheet-like absorbent composite (8) was prepared in the
following way as Example 8 using the VP crosslinked polymer (3)
obtained in Production Example 3.
[0487] Four pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The VP crosslinked polymer (3)
in an amount of 0.4 g (1.6 g in total) was uniformly sprayed on
each of the four non-woven fabrics (non-woven fabrics A to D).
Subsequently, water was sprayed with an atomizer on the VP
crosslinked polymer. The fabrics were stacked so that the
crosslinked polymer-side faces thereof faced each other, and they
were press-bonded (the non-woven fabrics A and B were press-bonded
and the non-woven fabric C and D were press-bonded). Thereafter,
similarly, 0.4 g (0.8 g in total) of the VP crosslinked polymer (3)
was uniformly sprayed on each of the two specimens, i.e. the
specimen of the non-woven fabrics A and B bonded to each other and
the specimen of the non-woven fabrics C and D bonded to each other.
Subsequently, water was sprayed with an atomizer on the VP
crosslinked polymer. The resulting two specimens were stacked to
each other so that the crosslinked polymer-side faces thereof faced
each other, and they were press-bonded (press-bonded to prepare a
specimen of the non-woven fabrics A, B, C, and D arranged in the
stated order). Thereafter, the resulting specimen was dried with a
dryer at 150.degree. C. for 60 minutes to obtain a sheet-like
absorbent composite (8). The absorbent composite (8) had a
multilayer structure in which resin layers were formed between the
four non-woven fabrics. The amount of the VP crosslinked polymer
(3) deposited on the non-woven fabric was 428 g/m.sup.2, and the
ratio of VP crosslinked polymer/non-woven fabric base material
(mass ratio) was 1.7.
Comparative Example 1
[0488] A sheet-like absorbent composite was prepared in the
following way as Comparative Example 1 using the comparative
crosslinked polymer (1) obtained in Comparative Production Example
1.
[0489] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven
fabric roll waste, material: pulp-polypropylene) each with a size
of 100 mm.times.50 mm were prepared. The comparative crosslinked
polymer (1) in an amount of 0.5 g (particles having a particle size
of 250 .mu.m or smaller obtained by classification) was uniformly
diffused on one of the two non-woven fabrics (non-woven fabric A).
Separately, water was diffused on the other non-woven fabric
(non-woven fabric B). The non-woven fabric B was placed on the
non-woven fabric A on which the comparative crosslinked polymer (1)
was diffused, and they were press-bonded. Thereafter, the resulting
specimen was dried with a dryer at 150.degree. C. for 60 minutes to
obtain a sheet-like absorbent composite. In the absorbent
composite, a resin layer was formed between the two non-woven
fabrics. The amount of the VP crosslinked polymer (1) deposited on
the non-woven fabric was 78 g/m.sup.2, and the ratio of VP
crosslinked polymer/non-woven fabric base material (mass ratio) was
0.6.
Example 9
[0490] A bag-like absorbent composite (9) was prepared in the
following way as Example 9 using the VP crosslinked polymer (4)
obtained in Production Example 4.
[0491] A bag-like product with a size of 40 mm.times.50 mm was
formed using one-side heat sealable paper (Heat-Ron GSP, Nippon
Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was
placed in the bag. The last one side was heat-sealed. Thus, a
bag-like absorbent composite (9) was obtained. The absorbent
composite (9) hardly scattered the VP crosslinked polymer (4)
powder, and the amount thereof was only less than 10%. The ratio of
VP crosslinked polymer/base material (mass ratio) was 2.5.
Example 10
[0492] A bag-like absorbent composite (10) was prepared in the
following way as Example 10 using the VP crosslinked polymer (4)
obtained in Production Example 4.
[0493] A bag-like product with a size of 40 mm.times.50 mm was
formed using one-side heat sealable paper (Heat Pac MW, Nippon
Paper Papylia Co., Ltd., basis weight: 50.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was
placed in the bag. The last one side was heat-sealed. Thus, a
bag-like absorbent composite (10) was obtained. The absorbent
composite (10) hardly scattered the VP crosslinked polymer (4)
powder, and the amount thereof was only less than 10%. The ratio of
VP crosslinked polymer/base material (mass ratio) was 1.0.
Example 11
[0494] A bag-like absorbent composite (11) was prepared in the
following way as Example 11 using the VP crosslinked polymer (4)
obtained in Production Example 4.
[0495] A bag-like product with a size of 40 mm.times.50 mm was
formed using non-woven fabric (ESCOTT, Unitika Ltd., material:
cotton, PET, PP) by heat-sealing (sealing by thermal compression
bonding) the three sides thereof. Then, 0.2 g of the VP crosslinked
polymer (4) was placed in the bag. The last one side was
heat-sealed. Thus, a bag-like absorbent composite (11) was
obtained. The absorbent composite (11) hardly scattered the VP
crosslinked polymer (4) powder, and the amount thereof was only
less than 10%. The ratio of VP crosslinked polymer/base material
(mass ratio) was 1.0.
Example 12
[0496] A bag-like absorbent composite (12) was prepared in the
following way as Example 12 using the VP crosslinked polymer (4)
obtained in Production Example 4.
[0497] A bag-like product with a size of 40 mm.times.50 mm was
formed using non-woven fabric (Daiwabo Polytec Co, Ltd., material:
rayon) by heat-sealing (sealing by thermal compression bonding) the
three sides thereof. Then, 0.2 g of the VP crosslinked polymer (4)
was placed in the bag. The last one side was heat-sealed. Thus, a
bag-like absorbent composite (12) was obtained. The absorbent
composite (12) hardly scattered the VP crosslinked polymer (4)
powder, and the amount thereof was only less than 10%. The ratio of
VP crosslinked polymer/base material (mass ratio) was 1.4.
Example 13
[0498] A bag-like absorbent composite (13) was prepared in the
following way as Example 13 using the VP crosslinked polymer (4)
obtained in Production Example 4.
[0499] A bag-like product with a size of 50 mm.times.80 mm was
formed using one-side heat sealable paper (Heat-Ron GSP, Nippon
Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 0.8 g of the VP crosslinked polymer (4) was
placed in the bag. The last one side was heat-sealed. Thus, a
bag-like absorbent composite (13) was obtained. The absorbent
composite (13) hardly scattered the VP crosslinked polymer (4)
powder, and the amount thereof was only less than 10%. The ratio of
VP crosslinked polymer/base material (mass ratio) was 4.8.
Example 14
[0500] A bag-like absorbent composite (14) was prepared in the
following way as Example 14 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0501] A product partitioned to have two pockets was formed using
one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia
Co., Ltd., basis weight: 20.0 g/m.sup.2), and 0.3 g (0.6 g in
total) of the VP crosslinked polymer (1) was placed in each pocket.
The pockets were hermetically sealed with a heat sealer. Thus, a
bag-like absorbent composite (14) with a size of 80 mm.times.50 mm
partitioned into two sections was obtained (the two sections each
had a size of 40 mm.times.50 mm). The absorbent composite (14)
hardly scattered the VP crosslinked polymer (1) powder, and the
amount thereof was only less than 10%. The ratio of VP crosslinked
polymer/base material (mass ratio) was 3.5.
Example 15
[0502] A bag-like absorbent composite (15) was prepared in the
following way as Example 15 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0503] A product partitioned to have two pockets was formed using
one-side heat sealable paper (Heat Pac MW, Nippon Paper Papylia
Co., Ltd., basis weight: 50.0 g/m.sup.2), and 0.3 g (0.6 g in
total) of the VP crosslinked polymer (1) was placed in each pocket.
The pockets were hermetically sealed with a heat sealer. Thus, a
bag-like absorbent composite (15) with a size of 80 mm.times.50 mm
partitioned into two sections was obtained (the two sections each
had a size of 40 mm.times.50 mm). The absorbent composite (15)
hardly scattered the VP crosslinked polymer (1) powder, and the
amount thereof was only less than 10%. The ratio of VP crosslinked
polymer/base material (mass ratio) was 1.5.
Example 16
[0504] A bag-like absorbent composite (16) was prepared in the
following way as Example 16 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0505] A product partitioned to have two pockets was formed using
one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia
Co., Ltd., basis weight: 20.0 g/m.sup.2), and 0.15 g (0.6 g in
total) of the VP crosslinked polymer (1) was placed in each pocket.
The pockets were hermetically sealed with a heat sealer. Thus, a
bag-like absorbent composite (16) with a size of 80 mm.times.50 mm
partitioned into four sections was obtained (the four sections each
had a size of 40 mm.times.25 mm). The absorbent composite (16)
hardly scattered the VP crosslinked polymer (1) powder, and the
amount thereof was only less than 10%. The ratio of VP crosslinked
polymer/base material (mass ratio) was 3.6.
Example 17
[0506] A bag-like absorbent composite (17) was prepared in the
following way as Example 17 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0507] A bag-like product with a size of 44 mm.times.52 mm was
formed using one-side heat sealable paper (Heat-Ron GSP, Nippon
Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 0.75 g of the VP crosslinked polymer (1) was
placed in the bag. The last one side was heat-sealed. Thus, a
tetrahedral (triangular pyramid) bag-like absorbent composite (17)
was obtained. The absorbent composite (17) hardly scattered the VP
crosslinked polymer (1) powder, and the amount thereof was only
less than 10%. The ratio of VP crosslinked polymer/base material
(mass ratio) was 7.9.
Example 18
[0508] A bag-like absorbent composite (18) was prepared in the
following way as Example 18 using the VP crosslinked polymer (1)
obtained in Production Example 1.
[0509] A bag-like product with a size of 44 mm.times.52 mm was
formed using a one-side heat sealable paper (Heat-Ron GSP, Nippon
Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 0.9 g of the VP crosslinked polymer (1) was
placed in the bag. The last one side was heat-sealed. Thus, a
tetrahedral (triangular pyramid) bag-like absorbent composite (18)
was obtained. The absorbent composite hardly scattered the VP
crosslinked polymer (1) powder, and the amount thereof was only
less than 10%. The ratio of VP crosslinked polymer/base material
(mass ratio) was 9.2.
Example 19
[0510] A bag-like absorbent composite (19) was prepared in the
following way as Example 19 using the polyethylene oxide
crosslinked polymer (7) obtained in Production Example 7.
[0511] A bag-like product with a size of 44 mm.times.52 mm was
formed using one-side heat sealable paper (Heat-Ron GSP, Nippon
Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by
heat-sealing (sealing by thermal compression bonding) the three
sides thereof. Then, 1.2 g of the polyethylene oxide crosslinked
polymer (7) was placed in the bag. The last one side was
heat-sealed. Thus, a tetrahedral (triangular pyramid) bag-like
absorbent composite (19) was obtained. The absorbent composite (19)
hardly scattered the polyethylene oxide crosslinked polymer (7),
and the amount thereof was only less than 10%. The ratio of
polyethylene oxide crosslinked polymer/base material (mass ratio)
was 12.2.
<Absorption Capacities of Sheet-Like Absorbent Composite for
Deionized Water, Ethanol, and Ethylene Glycol>
[0512] The following describes the evaluation method of the
deionized water absorption capacities of the sheet-like absorbent
composites obtained in Examples 1 to 8 and Comparative Example 1.
The ethanol and ethylene glycol absorption capacities were
determined according to the evaluation of liquid absorption
capacities of absorbent composite for solvent (including deionized
water) and solution at room temperature.
(Evaluation Method)
[0513] The sheet-like absorbent composite was cut into half to
prepare a 50 mm.times.50 mm piece, and the mass (W16 (g)) of the
piece was precisely measured. The absorbent composite was placed in
a Petri dish, and deionized water (conductivity: 10 .mu.S/cm or
less) was thinly applied thereto (the upper portion of the
absorbent composite was exposed to the air). The absorbent
composite was allowed to stand at room temperature (temperature:
23.+-.2.degree. C.) and atmospheric pressure. After two hours, the
absorbent composite was taken out by pinching the end thereof with
tweezers, placed one face down on KIMTOWEL (Nippon Paper Crecia
Co., Ltd.), and allowed to stand for five seconds. Then, the
absorbent composite was placed the other face down on KIMTOWEL and
allowed to stand for five seconds so that the liquid was removed.
Then, the mass of the absorbent composite (W17 (g)) was weighed.
The liquid absorption rate was determined according to the
following equation as the liquid absorption capacity.
Liquid absorption rate (g/g)=W17 (g)/W16 (g)
[0514] Table 1 shows the results. The following results demonstrate
that the sheet-like absorbent composite of the invention tends to
have a low deionized water absorption capacity when it has a low
mass ratio of crosslinked polymer/base material. In addition,
comparison between Examples 3 and 7 demonstrates that a better
liquid absorption capacity is obtained when no hydrophobic
synthetic rubber bonding agent is used. The sheet-like absorbent
composite having a multilayer structure obtained in Example 8 had a
thickness of 6 mm after it was swollen with water. The absorbent
composite obtained in Comparative Example 1 had a thickness of 10
mm or more after it was swollen with water, and peeling of the
water-swollen crosslinked body from the sheet was observed.
TABLE-US-00001 TABLE 1 Absorbent composite Example Example Example
Example Example Example Example Example Comparative 1 2 3 4 5 6 7 8
Example 1 Crosslinked polymer/ 0.1 0.4 0.7 0.9 1.1 0.6 0.8 1.7 0.6
Base material (mass ratio) Ion-exchange water 5.4 5.3 7.6 6.4 7.8
11.1 5.6 6.5 >100 absorption capapcity Ethanol absorption 5 5 7
6 7 11 5 6 2 capapcity Ethylene glycol 5 5 8 7 8 12 6 6 2
absorption capapcity
<Deionized Water, Ethanol, and Ethylene Glycol Absorption
Capacities of Bag-Like Absorbent Composite>
[0515] The deionized water, ethanol, and ethylene glycol absorption
capacities of the bag-like absorbent composites obtained in
Examples 9 to 19 were determined according to the evaluation of
liquid absorption capacities of absorbent composite for solvent
(including deionized water) and solution at room temperature. Table
2 shows the results.
TABLE-US-00002 TABLE 2 Absorbent composite Example Example Example
Example Example Example Example Example Example Example Example 9
10 11 12 13 14 15 16 17 18 19 Crosslinked polymer/ 2.5 1.0 1.0 1.4
4.8 3.5 1.5 3.6 7.9 9.2 12.2 Base material (mass ratio) Deionized
water 17.2 12.6 14.6 16.9 21.2 19.7 15.2 18.8 24.0 21.4 15.0
absorption capapcity Ethanol absorption 16 11 14 16 21 19 14 18 23
21 14 capapcity Ethylene glycol 18 12 15 17 21 20 16 19 24 21 15
absorption capapcity
<Propylene Glycol and Ink Absorption Capacities of Sheet-Like
Absorbent Composite>
[0516] The propylene glycol and ink absorption capacities of the
sheet-like absorbent composites obtained in Examples 1 to 8 and
Comparative Example 1 were evaluated. The following describes the
evaluation.
(Evaluation Method)
[0517] The sheet-like absorbent composite was cut into half to
prepare a 50 mm.times.50 mm piece, and the piece was placed in a
Petri dish. A solution (BCI-351 (dye BK), BCI-350 (PGBK (pigment
BK)), Canon Inc., or propylene glycol) in an amount four times the
weight of the absorbent composite was added to the Petri dish, and
the Petri dish was covered with a lid. The absorbent composite was
allowed to stand at room temperature (temperature: 23.+-.2.degree.
C.) and atmospheric pressure for two hours. Thereafter, the inside
of the Petri dish was observed to evaluate the presence or absence
of residual liquid (fluid liquid). Table 3 shows the results. In
Table 3, good means the absence of residual liquid, and bad means
the presence of residual liquid. For ink (dye, pigment), the lid
was removed from the Petri dish, water in the ink was evaporated
with a dryer at 50.degree. C., and the occurrence of discharge of
liquid from the liquid absorbent gel was evaluated. Table 3 shows
the results. In Table 3, good means the non-occurrence of discharge
of liquid, and bad means the occurrence of discharge of liquid.
[0518] The following results demonstrate that the sheet-like
absorbent composite of the invention is capable of absorbing and
retaining glycol and ink.
TABLE-US-00003 TABLE 3 Absorbent composite Example Example Example
Example Example Example Example Example Comparative 1 2 3 4 5 6 7 8
Example 1 Propylene glycol Good Good Good Good Good Good Good Good
Bad absorbency Ink (dye) absorbency Good Good Good Good Good Good
Good Good Good Discharge of ink Good Good Good Good Good Good Good
Good Bad (dye) liquid Ink (pigment) Good Good Good Good Good Good
Good Good Good absorbency Discharge of ink Good Good Good Good Good
Good Good Good Good (pigment) liquid
<Propylene Glycol and Ink Absorption Capacities of Bag-Like
Absorbent Composite>
[0519] The propylene glycol and ink absorption capacities of the
bag-like absorbent composites obtained in Examples 9 to 19 were
evaluated. The following describes the evaluation.
(Evaluation Method)
[0520] The bag-like absorbent composite was placed in a Petri dish.
A solution (BCI-351 (dye BK), BCI-350 (PGBK (pigment BK)), Canon
Inc., or propylene glycol) in an amount nine times the weight of
the absorbent composite was added to the Petri dish, and the Petri
dish was covered with a lid. The absorbent composite was allowed to
stand at room temperature (temperature: 23.+-.2.degree. C.) and
atmospheric pressure for eight hours. Thereafter, the inside of the
Petri dish was observed to evaluate the presence or absence of
residual liquid (fluid liquid). Table 4 shows the results. In Table
4, good means the absence of residual liquid, and bad means the
presence of residual liquid. For ink (dye, pigment), the lid was
removed from the Petri dish, water in the ink was evaporated with a
dryer at 50.degree. C., and the occurrence of discharge of liquid
from the liquid absorbent gel was evaluated. Table 4 shows the
results. In Table 4, good means the non-occurrence of discharge of
liquid, and bad means the occurrence of discharge of liquid.
[0521] The following results demonstrate that the bag-like
absorbent composite of the invention is capable of absorbing and
retaining glycol or ink.
TABLE-US-00004 TABLE 4 Absorbent composite Example Example Example
Example Example Example Example Example Example Example Example 9
10 11 12 13 14 15 16 17 18 19 Propylene glycol Good Good Good Good
Good Good Good Good Good Good Good absorbency Ink (dye) absorbency
Good Good Good Good Good Good Good Good Good Good Good Discharge of
ink Good Good Good Good Good Good Good Good Good Good Good (dye)
liquid Ink (pigment) Good Good Good Good Good Good Good Good Good
Good Good absorbency Discharge of ink Good Good Good Good Good Good
Good Good Good Good Good (pigment) liquid
<Evaluation of Water Diffusivity>
[0522] The water diffusivities of the sheet-like absorbent
composites (3), (5), and (6) obtained in Examples 3, 5, and 6 were
evaluated by the method described below. Separately, the same
evaluation was performed on an absorbent base material alone
(pulp-polypropylene non-woven fabric, pulp non-woven fabric, or
polyester non-woven fabric, each with a size of 100 mm.times.20
mm).
(Evaluation Method)
[0523] Each of the sheet-like absorbent composites with a size of
100 mm.times.50 mm was cut into a size of 100 mm.times.20 mm. The
absorbent composites and the non-woven fabrics were hung so that
the 100-mm length side was perpendicular to the ground. The
absorbent composites were immersed in colored water so that the
length of 5 mm from the lower edge thereof was immersed therein,
and allowed to stand at room temperature (temperature:
23.+-.2.degree. C.) and atmospheric pressure for 24 hours.
Thereafter, the length of the portion colored with the colored
water of each composite was measured.
[0524] Table 5 shows the results. Here, the upper limit of the
length was 100 mm (10 cm). The following results demonstrate that a
pulp-polypropylene non-woven fabric and a pulp non-woven fabric
have a higher water diffusivity as an absorbent base material, and
the absorbent composites (3) and (5) of the invention including
such absorbent base materials with a high diffusivity have a higher
diffusivity than the absorbent composite (6) including a polyester
non-woven fabric.
TABLE-US-00005 TABLE 5 Length of colored portion (cm) Absorbent
Absorbent Absorbent composite (3) composite (5) composite (6) in
Example 3 in Example 5 in Example 6 Base material alone 10 6 1
Absorbent composite 10 10 4
<Evaluation of Liquid Absorption Speed>
[0525] The absorbent composites (3) and (14) obtained in Examples 3
and 14 and the absorbent composite obtained in Comparative Example
1 were subjected to the following evaluation. The same evaluation
was performed on the crosslinked polymer alone (the VP crosslinked
polymers (3) and (1) obtained in Production Examples 3 and 1 and
the comparative crosslinked polymer (1)).
(Evaluation Method)
[0526] Each of the absorbent composites was placed in a Petri dish
(diameter: 100 mm). Propylene glycol in an amount four times the
weight of the absorbent composite was poured over the absorbent
composite, and the period of time required for disappearance of the
residual liquid (liquid absorption speed) was evaluated. For the
absorbent composite obtained in Comparative Example 1, which did
not absorb propylene glycol, water in an amount 20 times the weight
of the absorbent composite was used instead of propylene glycol,
and the period of time required for disappearance of the residual
liquid (liquid absorption speed) was evaluated. The same evaluation
was performed on the crosslinked polymer alone. Here, the
crosslinked polymer was uniformly dispersed in the Petri dish.
Table 6 shows the results.
[0527] The absorbent composites obtained in Examples 3 and 14 had a
higher liquid absorption speed than the crosslinked polymer alone.
In contrast, no difference was observed in liquid absorption speed
between the comparative absorbent composite including the
comparative crosslinked polymer (1) and the crosslinked polymer
alone. These results demonstrate that the combination of the
nonionic crosslinked polymer of the invention and the absorbent
base material results in a particular synergistic effect that is
not obtained from a prior art crosslinked polymer containing
polyacrylic acid (salt) as a main component.
TABLE-US-00006 TABLE 6 Period of time required for disappearance of
residual liquid (seconds) Absorbent Absorbent Absorbent composite
(1) composite (3) composite (14) of Comparative of Example 3 of
Example 14 Example 1 Crosslinked polymer 124 231 <10 alone
Absorbent composite <10 19 <10
Example 20
[0528] A sheet-like absorbent composite (20) was prepared in the
following way as Example 20 using the VP crosslinked polymer (2)
obtained in Production Example 2.
[0529] First, 50 parts by weight of the VP crosslinked polymer (2)
and 50 parts by weight of wood-pulverized pulp were mixed together
in a dry manner with a mixer. Next, the resultant mixture was
air-laid into a web (sheet-like fiber) with a size of 120
mm.times.400 mm on a wire screen of 400 mesh (mesh size: 38 .mu.m)
with a batch type air laying device. In addition, the web was
pressed for five seconds under a pressure of 196.14 kPa. Thus, a
sheet with a weight of about 0.047 g/m.sup.2 was obtained.
Subsequently, the sheet was cut into a facial mask shape and placed
between two heat-sealable nylon nonwoven fabrics with a facial mask
shape. The edges of the nonwoven fabrics were bonded by thermal
fusion to obtain a sheet-like absorbent composite (20). The ratio
of VP crosslinked polymer/non-woven fabric base material (mass
ratio) was 0.1.
[0530] The sheet-like absorbent composite (20) and a similarly
formed facial mask free from the VP crosslinked polymer were
immersed in a skin lotion shown in Table 7. They were applied to
the face, and the effects thereof were examined. The result was
that the sheet-like absorbent composite containing the VP
crosslinked polymer was capable of retaining a moisturizing effect
longer.
TABLE-US-00007 TABLE 7 Component Amount (weight %) Sorbitol 3.00
1,3-Butylene glycol 1.00 Glycerol 2.00 Citric acid 0.01 Citric acid
Na 0.10 Arginine 0.10 Glycyrrhizin acid 2K 0.05 Ethanol 7.00
Antiseptic agent Appropriate quantity Perfume Trace Purified water
Added up to 100 in total
Example 21
[0531] The same steps as in Example 20 were performed from the
start to pressing of the web for five seconds under a pressure of
196.14 kPa to obtain a sheet. Subsequently, a liquid impermeable
polypropylene sheet as a so-called back sheet (liquid impermeable
sheet), the above sheet (cut into a size of 10.times.8 cm), and a
cotton non-woven fabric as a front sheet (liquid permeable sheet)
were bonded to each other in the stated order with a double-stick
tape. Thus, a sheet-like absorbent composite (21) was obtained. The
ratio of VP crosslinked polymer/non-woven fabric base material
(mass ratio) was 0.1.
[0532] The liquid permeable sheet-side face of each of the
sheet-like absorbent composite (21) and a similarly formed sheet
free from the VP crosslinked polymer was applied to an underarm,
and the effects thereof were examined. The result was that the
sheet-like absorbent composite containing the VP crosslinked
polymer was capable of absorbing sebum and perspiration and had a
higher ability to deodorize perspiration odor and body odor.
Example 22
[0533] The same steps as in Example 20 were performed from the
start to pressing of the web for five seconds under a pressure of
196.14 kPa to obtain a sheet. Subsequently, the resultant sheet was
placed between two pulp-polypropylene non-woven fabrics, and they
were bonded to each other with a double-stick tape. Thus, a
sheet-like absorbent composite (22) was obtained. The ratio of VP
crosslinked polymer/non-woven fabric base material (mass ratio) was
0.2.
[0534] The sheet-like absorbent composite (22) had an excellent
deodorizing ability and an excellent ability to wipe off dirt (such
as oil component, sebum, and perspiration).
Example 23
[0535] A deodorant was prepared using the sheet-like absorbent
composite (8) in the following way.
[0536] The sheet-like absorbent composite (8) was immersed in a
commercially available fragrant liquid for one hour or more. Then,
the sheet-like absorbent composite (8) was hung so that the long
side thereof was perpendicular to the ground, immersed in the
fragrant liquid so that the length of 1 cm from the lower edge
thereof was immersed therein, and allowed to stand in a room. The
result was that the sheet-like absorbent composite exerted
fragrance for a long time and had excellent deodorant
properties.
Comparative Example 2
[0537] Comparative Example 2 was performed as follows. The liquid
absorption capacity of a non-woven fabric (non-woven fabric filter
paper T-811, Advantec Toyo Kaisha, Ltd., thickness: 1.15 mm, mass:
110 g/m.sup.2, material: polyester) for an ink mixture was measured
according to the following measurement method. As the result of the
measurement, the liquid absorption capacity was 6 (g/g). Further,
leakage of the liquid by application of pressure was observed.
[0538] The results confirm that the non-woven fabric has a low ink
absorption capacity and causes leakage of the liquid by application
of pressure, and thus the non-woven fabric seems not to strongly
retain the liquid. This clearly demonstrates that the VP
crosslinked polymer of the invention greatly contributes to the
liquid absorption capacity (e.g. Example 6) of the absorbent sheet
including the ink absorbing agent of the invention and a polyester
non-woven fabric as a base material.
(Evaluation Method)
[0539] First, 3 g of an ink mixture (a solution prepared by mixing
the same amounts of BCI-351 (BK, C, M, and Y) and BCI-350 (PGBK))
was placed in a 50-mL (specified volume) glass screw tube at room
temperature. A non-woven fabric with a size of 4 cm.times.5 cm was
prepared, and the mass thereof was precisely weighed (mass: W18
(g)). The non-woven fabric was put into the screw tube containing
the ink mixture. These operations were performed in a room at a
temperature of 23.+-.2.degree. C., a relative humidity of 50.+-.5%,
and atmospheric pressure. The non-woven fabric was allowed to stand
at room temperature (temperature: 23.+-.2.degree. C.) and
atmospheric pressure. After 24 hours, the non-woven fabric was
taken out by pinching the end thereof with tweezers, placed one
face down on KIMTOWEL (Nippon Paper Crecia Co., Ltd.), and allowed
to stand for five seconds. Then, the non-woven fabric was placed
the other face down on KIMTOWEL and allowed to stand for five
seconds so that the liquid was removed. Then, the mass of the
non-woven fabric (W19 (g)) was weighed. The liquid absorption rate
was determined according to the following equation as the liquid
absorption capacity for various ink liquid mixtures.
Liquid absorption rate (g/g)=W19 (g)/W18 (g)
* * * * *