U.S. patent application number 13/642773 was filed with the patent office on 2013-02-14 for resin composition whose lubricity under wet conditions is maintained.
This patent application is currently assigned to SUMITOMO SEIKA CHEMICALS CO., LTD.. The applicant listed for this patent is Yusuke Nishikawa, Tatsuo Ohtani, Hitoshi Ozawa. Invention is credited to Yusuke Nishikawa, Tatsuo Ohtani, Hitoshi Ozawa.
Application Number | 20130040868 13/642773 |
Document ID | / |
Family ID | 44834135 |
Filed Date | 2013-02-14 |
United States Patent
Application |
20130040868 |
Kind Code |
A1 |
Ozawa; Hitoshi ; et
al. |
February 14, 2013 |
RESIN COMPOSITION WHOSE LUBRICITY UNDER WET CONDITIONS IS
MAINTAINED
Abstract
Provided is a resin composition which has excellent lubricity
and a good touch feeling under wet conditions and suffers from
little deterioration in the lubricity or the good touch feeling
even if used repeatedly, and is excellent in flexibility. More
specifically, the resin composition contains 100 parts by mass of a
water-absorbing polymer and 60 to 500 parts by mass of a
thermoplastic resin that has a type D durometer hardness (HDD) of
10 to 60.
Inventors: |
Ozawa; Hitoshi; (Himeji-shi,
JP) ; Ohtani; Tatsuo; (Himeji-shi, JP) ;
Nishikawa; Yusuke; (Himeji-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ozawa; Hitoshi
Ohtani; Tatsuo
Nishikawa; Yusuke |
Himeji-shi
Himeji-shi
Himeji-shi |
|
JP
JP
JP |
|
|
Assignee: |
SUMITOMO SEIKA CHEMICALS CO.,
LTD.
Kako-gun, Hyogo
JP
|
Family ID: |
44834135 |
Appl. No.: |
13/642773 |
Filed: |
April 15, 2011 |
PCT Filed: |
April 15, 2011 |
PCT NO: |
PCT/JP2011/059418 |
371 Date: |
October 22, 2012 |
Current U.S.
Class: |
508/386 |
Current CPC
Class: |
C08L 75/08 20130101;
C08L 71/02 20130101; C08G 18/4833 20130101; C08L 75/08 20130101;
C08L 71/02 20130101; C08L 71/02 20130101; C08L 71/02 20130101; C08L
23/0853 20130101; C08L 33/064 20130101; C08L 31/04 20130101; C08L
33/08 20130101; C08L 2205/03 20130101; C08L 33/02 20130101 |
Class at
Publication: |
508/386 |
International
Class: |
C10M 149/12 20060101
C10M149/12 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 23, 2010 |
JP |
2010-100156 |
Claims
1. A resin composition comprising 100 parts by mass of a
water-absorbing modified polyalkylene oxide and 60 to 500 parts by
mass of a thermoplastic resin having a type D durometer hardness
(HDD) of 10 to 60.
2. The resin composition according to claim 1, wherein the
water-absorbing modified polyalkylene oxide is a modified
polyalkylene oxide obtained by reacting a polyalkylene oxide
compound, a diol compound and a diisocyanate compound.
3. The resin composition according to claim 1, wherein the
water-absorbing modified polyalkylene oxide has a water absorption
ability of 10 to 40 [g/g].
4. The resin composition according to claim 1, wherein the
water-absorbing modified polyalkylene oxide has a proportion of
water-soluble component of 5 to 30% by mass.
5. The resin composition according to claim 1, wherein the
thermoplastic resin is an ethylene/vinyl acetate copolymer, an
ethylene/acrylic acid copolymer, an ethylene/ethyl acrylate
copolymer or a combination thereof.
6. The resin composition according to claim 2, wherein the
water-absorbing modified polyalkylene oxide has a water absorption
ability of 10 to 40 [g/g].
7. The resin composition according to claim 2, wherein the
water-absorbing modified polyalkylene oxide has a proportion of
water-soluble component of 5 to 30% by mass.
8. The resin composition according to claim 3, wherein the
water-absorbing modified polyalkylene oxide has a proportion of
water-soluble component of 5 to 30% by mass.
9. The resin composition according to claim 2, wherein the
thermoplastic resin is an ethylene/vinyl acetate copolymer, an
ethylene/acrylic acid copolymer, an ethylene/ethyl acrylate
copolymer or a combination thereof.
10. The resin composition according to claim 3, wherein the
thermoplastic resin is an ethylene/vinyl acetate copolymer, an
ethylene/acrylic acid copolymer, an ethylene/ethyl acrylate
copolymer or a combination thereof.
11. The resin composition according to claim 4, wherein the
thermoplastic resin is an ethylene/vinyl acetate copolymer, an
ethylene/acrylic acid copolymer, an ethylene/ethyl acrylate
copolymer or a combination thereof.
Description
1. TECHNICAL FIELD
[0001] The present invention relates to a resin composition whose
lubricity under wet conditions is maintained. More particularly,
the present invention relates to a resin composition obtained by
mixing a water-absorbing modified polyalkylene oxide with a
thermoplastic resin.
2. BACKGROUND ART
[0002] There has heretofore been proposed a razor blade cartridge
in which a water-soluble resin such as a polyalkylene oxide is
attached, penetrated or dispersed in a part of a razor blade
cartridge made of plastic in order to reduce the resistance between
a part of a razor and the face or the like (Patent Document 1).
[0003] Moreover, some composites in which a water-absorbing resin
is swollen to release a variety of aids upon immersion in water,
due to mixing of a water-soluble resin and a water-absorbing resin,
have been used in a smoother for wet shaving (Patent Document
2).
[0004] In addition, as a polymer composite used for wet shaving
instruments and medical instruments, a polymer composite containing
a water-insoluble polymer, and a water-sensitive copolymer
polymerized from an alkylene oxide monomer and an epoxy-functional
monomer has been disclosed (Patent Document 3).
PRIOR ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: JP 54-94961 A [0006] Patent Document 2:
JP 9-502632 A [0007] Patent Document 3: JP 2004-509207 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0008] The razor blade cartridge described in Patent Document 1,
the composite described in Patent Document 2, and the polymer
composite described in Patent Document 3 give lubricity to a
surface of the composite or the like utilizing dissolution of a
water-soluble resin such as a polyalkylene oxide under wet
conditions.
[0009] However, the water-soluble resin has low compatibility with
a thermoplastic resin or the like and is merely scattered on a
surface of the composite or the like in a massive form. For this
reason, lubricity at the initial stage of use is excellent, but the
scattered water-soluble resin is dropped in a massive form by
repeated used, and the lubricity is lost in a short term.
[0010] In addition, generally, in a water-soluble resin such as a
polyalkylene oxide, lubricity is improved as the molecular weight
increases, but cobwebbing under wet conditions becomes remarkable
and, further, the melt viscosity thereof becomes high. Therefore,
it is necessary to raise the temperature upon processing. For this
reason, the resin is often mixed with a hard resin such as a high
impact polystyrene or a polystyrene having a high processing
temperature, and the hardness of the resulting resin composition is
high. Therefore, there is a problem that, when the resin is mounted
on, for example, a razor requiring flexibility that is equipped
with a bendable blade in order to fit with the skin, the resin is
cracked upon bending.
[0011] On the other hand, when the water-soluble resin is mixed
with resins obtained by copolymerizing a rubber component having
flexibility, since these resins have to be processed at a low
temperature, there is a problem that the water-soluble resin such
as a polyalkylene oxide cannot be sufficiently molten and is
brought into a state where the water-soluble resin such as the
polyalkylene oxide is scattered in a composition, and not only
design characteristics and lubricity upon repeated use are
deteriorated, but also objective flexibility is suppressed.
[0012] An object of the present invention is to provide a resin
composition which has excellent lubricity and a good touch feeling
under wet conditions and suffers from little deterioration in the
lubricity or the good touch feeling even if used repeatedly, and is
excellent in flexibility.
Means for Solving the Problems
[0013] The present inventors studied earnestly in order to solve
the above-described problems and found that a resin composition
containing a water-absorbing modified polyalkylene oxide and a
thermoplastic resin having a type D durometer hardness (HDD) of 10
to 60 is excellent in lubricity, does not lose its lubricity even
if used repeatedly, and has flexibility. Thus, they have
accomplished the present invention.
[0014] That is, the present invention relates to a resin
composition which maintains excellent lubricity and a good touch
feeling even if used repeatedly, and has flexibility. More
particularly, the present invention relates to a resin composition
containing 100 parts by mass of a water-absorbing modified
polyalkylene oxide and 60 to 500 parts by mass of a thermoplastic
resin having a type D durometer harness (HDD) of 10 to 60.
Effects of the Invention
[0015] Since the resin composition of the present invention does
not lose lubricity and a good touch feeling even if used
repeatedly, and is also excellent in flexibility, it can be widely
used in wet shaving instruments represented by a razor, and medical
instruments such as a catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic view showing a method of obtaining a
mean coefficient of friction (MIU).
[0017] FIG. 2 is a schematic view showing a method of obtaining a
deviation in mean coefficient of friction (MMD).
MODE FOR CARRYING OUT THE INVENTION
[0018] The resin composition of the present invention is obtained
by mixing a water-absorbing modified polyalkylene oxide with a
thermoplastic resin having a type D durometer hardness (HDD) of 10
to 60.
[0019] The water-absorbing modified polyalkylene oxide used in the
resin composition of the present invention is, for example, a
modified polyalkylene oxide obtained by reacting a polyalkylene
oxide compound, a diol compound and a diisocyanate compound. Such a
modified polyalkylene oxide has thermoplasticity. For this reason,
the modified polyalkylene oxide has good compatibility with a
thermoplastic resin, and a resin composition having flexibility can
be obtained.
[0020] As the polyalkylene oxide compound, a polyalkylene oxide
compound having 90% by mass or more of ethylene oxide groups is
preferable, and a polyalkylene oxide compound having 95% by mass or
more of ethylene oxide groups is more preferable. When the amount
of ethylene oxide groups is less than 90% by mass, there is a
possibility that lubricity at the initial stage of the resulting
resin composition is deteriorated.
[0021] As the polyalkylene oxide compound, a polyalkylene oxide
compound having a number average molecular weight of 5,000 to
50,000 is preferable, and a polyalkylene oxide compound having a
number average molecular weight of 10,000 to 30,000 is more
preferable. When a polyalkylene oxide compound having a number
average molecular weight of less than 5,000 is used, there is a
possibility that lubricity at the initial stage of the resulting
resin composition is deteriorated. When a polyalkylene oxide
compound having a number average molecular weight of more than
50,000 is used, there is a possibility that the melt viscosity of
the resulting water-absorbing modified polyalkylene oxide is high,
compatibility with a thermoplastic resin is deteriorated, and it
becomes difficult to maintain lubricity upon repeated use.
[0022] Examples of the diol compound include ethylene glycol,
diethylene glycol, triethylene glycol, tetraethylene glycol,
propylene glycol, dipropylene glycol, trimethylene glycol,
1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol and 1,9-nonanediol. Among these diol compounds, from
the viewpoints that the resulting water-absorbing modified
polyalkylene oxide is excellent in the water absorption ability,
that elution of a water-soluble component is suppressed, and that
stability is excellent, ethylene glycol and 1,4-butanediol are
preferably used. These diol compounds may each be used alone, or
two or more kinds may be used in combination.
[0023] The proportion of use of the diol compound is preferably 0.8
to 2.5 mol, more preferably 1.0 to 2.0 mol based on 1 mol of the
polyalkylene oxide compound. When the proportion of use of the diol
compound is less than 0.8 mol, there is a possibility that
lubricity cannot be maintained when the resulting resin composition
is used repeatedly. On the other hand, when the proportion of use
of the diol compound is more than 2.5 mol, there is a possibility
that lubricity at the initial stage of the resulting resin
composition is deteriorated. The molar number of the polyalkylene
oxide compound can be obtained by dividing the mass thereof by the
number average molecular weight thereof.
[0024] The diisocyanate compound is not particularly limited as far
as it is a compound having two isocyanate groups (--NCO) in the
same molecule, and examples thereof include 4,4'-diphenylmethane
diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI),
dicyclohexylmethane-4,4'-diisocyanate (HMDI),
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),
1,8-dimethylbenzol-2,4-diisocyanate, and 2,4-tolylene diisocyanate
(TDI). Among these diisocyanate compounds, from the viewpoints of
compatibility with a thermoplastic resin, suppression of elution of
a water-soluble compound, and excellent stability,
dicyclohexylmethane-4,4'-diisocyanate (HMDI) and 1,6-hexamethylene
diisocyanate (HDI) are preferably used. These diisocyanate
compounds may each be used alone, or two or more kinds may be used
in combination.
[0025] The proportion of use of each of the polyalkylene oxide
compound, the diol compound and the diisocyanate compound is
determined so that the ratio of the molar number of isocyanate
groups of the diisocyanate compound relative to the total molar
number of terminal hydroxyl groups of the polyalkylene oxide
compound and hydroxyl groups of the diol compound [R value=(--NCO
group/--OH group)] is preferably in the range of 0.7 to 1.2, more
preferably in the range of 0.8 to 1.05. When the R value is less
than 0.7, there is a possibility that the resulting water-absorbing
modified polyalkylene oxide is water-soluble, and lubricity cannot
be maintained when the resulting resin composition is used
repeatedly. On the other hand, when the R value is more than 1.2,
there is a possibility that the melt viscosity of the resulting
water-absorbing modified polyalkylene oxide becomes high, and
compatibility with a thermoplastic resin is deteriorated. The molar
number of the polyalkylene oxide compound can be obtained by
dividing the mass thereof by the number average molecular weight
thereof.
[0026] Examples of a method of reacting the polyalkylene oxide
compound, the diol compound and the diisocyanate compound include:
a method of dissolving or dispersing the compounds in a reaction
solvent such as toluene, xylene, or dimethylformamide to react; and
a method of uniformly mixing these compounds in a powder state or a
solid state, and heating the mixture to a predetermined temperature
to react. From the viewpoint of industrial implementation, a method
of continuously feeding raw materials in a molten state, and mixing
the raw materials in a multi-screw extruder to react is preferable.
The temperature of the reaction is preferably 70 to 210.degree.
C.
[0027] When the water-absorbing modified polyalkylene oxide is
produced, from the viewpoint of promoting a reaction, a small
amount of triethylamine, triethanolamine, dibutyltin dilaurate,
dioctyltin dilaurate, tin 2-ethylhexanoate, triethylenediamine or
the like can also be added to a reaction system.
[0028] Thus, by reacting the polyalkylene oxide compound, the diol
compound and the diisocyanate compound, a water-absorbing modified
polyalkylene oxide can be obtained.
[0029] The melt viscosity of the water-absorbing modified
polyalkylene oxide used in the resin composition of the present
invention, when measured using a flow tester (condition:
170.degree. C., 5.0 MPa, a die having a diameter of 1 mm and a
length of 1 mm is used), is preferably 100 to 800 [Pas], more
preferably 200 to 600 [Pas]. When the melt viscosity is less than
100 [Pas], there is a possibility that lubricity at the initial
stage of the resulting resin composition is deteriorated. When the
melt viscosity is more than 800 [Pas], there is a possibility that
compatibility with a thermoplastic resin is deteriorated.
[0030] The water absorption ability of the water-absorbing modified
polyalkylene oxide used in the resin composition of the present
invention is preferably 10 to 40 [g/g], more preferably 15 to 35
[g/g]. When the water absorption ability of the water-absorbing
modified polyalkylene oxide is less than 10 [g/g], there is a
possibility that lubricity at the initial stage of the resulting
resin composition is deteriorated. When the water absorption
ability of the water-absorbing modified polyalkylene oxide is more
than 40 [g/g], there is a possibility that lubricity cannot be
maintained when the resulting resin composition is used repeatedly.
In the present invention, the water absorption ability is a value
measured by a method described later.
[0031] The ratio of water-soluble component of the water-absorbing
modified polyalkylene oxide used in the present invention, from the
viewpoint of improving the lubricity of the resulting resin
composition, is preferably 5 to 30% by mass, more preferably 10 to
20% by mass. When the water-soluble component of the
water-absorbing modified polyalkylene oxide is less than 5% by
mass, there is a possibility that lubricity at the initial stage is
deteriorated. When the water-soluble component of the
water-absorbing modified polyalkylene oxide is more than 30%, there
is a possibility that lubricity cannot be maintained when the
resulting resin composition is used repeatedly. The ratio of
water-soluble component in the present invention is a value
measured by a method described later.
[0032] The thermoplastic resin used in the resin composition of the
present invention has a type D durometer hardness (HDD) of 10 to
60, preferably 20 to 50. When the HDD is less than 10, a force
returning to the original shape (restoring force) is reduced when a
force is applied to the resulting resin composition. When the HDD
is more than 60, if the resulting resin composition is bent, the
bent part is whitened and does not return to the original shape,
and lubricity cannot be maintained when the resin composition is
used repeatedly.
[0033] Examples of the thermoplastic resin having an HDD of 10 to
60 include an ethylene/methacrylic acid copolymer, an
ethylene/vinyl acetate copolymer, an ethylene/acrylic acid
copolymer, an ethylene/ethyl acrylate copolymer, and an
acrylonitrile/butadiene/styrene copolymer (ABS). Among these
thermoplastic resins, from the viewpoint that the resin has good
compatibility with the water-absorbing modified polyalkylene oxide,
an ethylene/vinyl acetate copolymer, an ethylene/acrylic acid
copolymer, and an ethylene/ethyl acrylate copolymer are preferably
used. These thermoplastic resins may each be used alone, or two or
more kinds may be used in combination.
[0034] The proportion of use of the thermoplastic resin having an
HDD of 10 to 60 is 60 to 500 parts by mass, preferably 100 to 300
parts by mass relative to 100 parts by mass of the water-absorbing
modified polyalkylene oxide. When the proportion of use of the
thermoplastic resin is less than 60 parts by mass, there is a
problem that, when the resulting resin composition is contacted
with water, the swelling ratio in water is high, the dimension is
greatly changed by dilation and, for example, the resin is dropped
from a razor blade cartridge. On the other hand, when the
proportion of use of the thermoplastic resin is more than 500 parts
by mass, lubricity at the initial stage of the resulting resin
composition is deteriorated.
[0035] Examples of a method for producing the resin composition of
the present invention include 1) a method of mixing the
water-absorbing modified polyalkylene oxide with the thermoplastic
resin having an HDD of 10 to 60 using a mixing machine such as a
Henschel mixer or a blender, or supplying a predetermined amount of
each of them to a kneader, a roll, an extruder or the like with a
metering feeder, and melt-mixing them, and 2) a method of reacting
the polyalkylene oxide, the diol compound and the diisocyanate
compound in the thermoplastic resin having an HDD of 10 to 60,
which has been molten in advance.
[0036] As an instrument in which the melting, the melt-mixing, or
the reaction is performed, from the viewpoint that mixability of
the components is excellent, a twin-screw extruder is preferably
used.
[0037] After the melt-mixing or the reaction, the melt may be
molded into a desired shape such as a pellet, a sheet (in the
present description, the sheet refers to a sheet having a thickness
of 0.2 mm or more), a film (in the present description, the film
refers to a film having a thickness of less than 0.2 mm), a bar, or
a fiber by performing injection molding, extrusion molding or
inflation molding.
[0038] When the resin composition of the present invention is
produced, from the viewpoint of preventing degradation of the
components or the resulting resin composition, a stabilizer; from
the viewpoint of improving weather resistance of the resulting
resin composition, a UV absorber; from the viewpoint of coloring
the resulting resin composition, a pigment, a coloring material
etc.; from the viewpoint of imparting foamability to the resulting
resin composition, a soap material; and the like may be added.
[0039] From the viewpoint that processing at a low temperature is
easy, the resin composition of the present invention can be mixed
with a drug which is easily thermally degraded such as ascorbic
acid, sodium ascorbate, or ethylascorbic acid. The resin
composition with such a drug added thereto can effectively release
the drug when contacted with water. The amount of addition of the
drug is preferably 0.05 to 5.0 parts by mass, more preferably 0.1
to 3.5 parts by mass based on 100 parts by mass of the resin
composition. When the amount of addition of the drug is less than
0.05 parts by mass, the amount of drug to be released from the
resulting resin composition is small, and there is a possibility
that the effect of the drug is not exerted. When the amount of
addition of the drug is more than 5.0 parts by mass, there is a
possibility that a surface of the resin composition is roughened to
be brought into an irregular state, and not only smoothness is
reduced but also control of the release amount of the drug becomes
impossible.
[0040] The present invention will be described in more detail by
way of examples and comparative examples, but the present invention
is not limited thereto.
[Evaluation Methods]
[0041] The water absorption ability and the ratio of water-soluble
component of the modified polyalkylene oxide and the cross-linked
polyacrylate described in production examples, the melt viscosity
of the modified polyalkylene oxide, the type D durometer hardness
(HDD) of the thermoplastic resin used in examples, as well as the
bending test, swelling ratio, slimy feeling and friction physical
properties of the resin composition obtained in examples and
comparative examples were measured and evaluated according to the
following methods.
(1) Water Absorption Ability
[0042] The water absorption ability of the modified polyalkylene
oxide and the cross-linked polyacrylate were measured by the
following method.
[0043] About 1 [g] of the modified polyalkylene oxide or the
cross-linked polyacrylate was weighed (A [g]), and immersed in 100
[mL] of ion exchange water measured in a 200 mL beaker at room
temperature (22.degree. C.) for 24 hours to gel. Thereafter, the
gel was filtered with a wire gauze of 200 meshes (pore size: 75
.mu.m), the mass thereof (B [g]) was measured, and the water
absorption ability was calculated by the following equation.
Water absorption ability[g/g]=B/A
(2) Ratio of Water-Soluble Component
[0044] A gel obtained by the measurement of (1) Water absorption
ability was dried in a hot air dryer set at 105.degree. C. to a
constant weight [C (g)], and the ratio of water-soluble component
was calculated by the following equation, provided that A is the
same as A in the measurement of (1) Water absorption ability.
Ratio of water-soluble component[mass %]=(A-C)/A.times.100
(3) Melt Viscosity
[0045] 1.5 g of the modified polyalkylene oxide or the like was
measured using a flow tester (Model: CFT-500C, manufactured by
Shimadzu Corporation) under the following conditions.
[0046] Load: 5.0 MPa
[0047] Measurement temperature: 170.degree. C.
[0048] Die diameter: 1 mm
[0049] Die length: 1 mm
(4) Type D Durometer Hardness (HDD)
[0050] The type D durometer hardness (HDD) means the "hardness"
measured in "type D durometer hardness" in accordance with "Method
of testing durometer hardness of plastic" described in Japanese
Industrial Standard: JIS K 7215 (1986).
[0051] Specifically, after confirming that the flatness and
parallelism of a sheet surface or a film surface of a molded resin
composition were good, a plurality of sheets or films were piled so
that the whole thickness (T) became 6 mm or more, and this was used
as a measurement sample. After confirming that adherability between
a plurality of sheets or films was good, the HDD of the resulting
measurement sample was measured on a durometer holder.
(5) Bending Test
[0052] Sheets or films of resin compositions obtained in examples
and comparative examples were each cut into 2 cm (width: W).times.5
cm (length: L), and these were used as measurement samples.
[0053] Each measurement sample was bent at 90 degrees at a part 1
cm from an end (short side of 2 cm in width) of the measurement
sample (the rest: 4 cm), and the bent part was evaluated in
accordance with the following criteria. In addition, separately,
using the same measurement samples and changing the bending angle
to 180 degrees, the same evaluation was performed.
[0054] Evaluation Criteria
[0055] A: A bent part is not whitened and returns to the original
sheet shape or film shape (presence of a restoring force).
[0056] B: A bent part is whitened but returns to the original sheet
shape or film shape (presence of restoring force).
[0057] C: There is whitening at a bent part, and the bent part does
not return to the original sheet shape or film shape (absence of
restoring force).
(6) Swelling Ratio
(a) Swelling Ratio of Sheet
[0058] Sheets of resin compositions obtained in examples and
comparative examples were each cut into 2 cm (W).times.5 cm (L),
and these were used as measurement samples.
[0059] The mass (E [g]) of each measurement sample was measured,
and the sample was immersed in 100 [mL] of ion exchange water
measured in a 200 mL beaker at room temperature (22.degree. C.) for
24 hours to swell. Thereafter, the measurement sample was taken
out, water on the sample surface was wiped using a paper towel, and
the mass (F [g]) thereof was measured. When the swelling ratio is
less than 300%, it can be judged that the change in dimension due
to swelling is small. When a gel-like water-absorbing resin was
desorbed from a swollen resin composition, this was evaluated as
"gel desorption".
Swelling ratio[%]=(F-E)/E.times.100
(b) Swelling Ratio of Film
[0060] Separately, films of resin compositions obtained in examples
and comparative examples were each cut into 2 cm (W).times.5 cm
(L), and these were used as measurement samples.
[0061] The mass (E [g]) of each measurement sample was measured,
and the sample was immersed in 100 [mL] of ion exchange water
measured in a 200 mL beaker at room temperature (22.degree. C.) for
1 minute to swell. The measurement sample was taken out, water on
the sample surface was wiped using a paper towel, and the mass (F
[g]) thereof was measured. When the swelling ratio is less than
200%, it can be judged that the change in dimension due to swelling
is small. When a gel-like water-absorbing resin was desorbed from a
swollen resin composition, this was evaluated as "gel
desorption".
Swelling ratio[%]=(F-E)/E.times.100
(7) Slimy Feeling
[0062] Sheets or films of the resin compositions obtained in
examples and comparative examples were each cut into 2 cm
(W).times.5 cm (L), and these were used as measurement samples.
[0063] Each measurement sample obtained in an example or the like
was immersed in 100 mL of ion exchange water measured in a 200 mL
beaker for 1 minute, water on a sample surface was wiped with a
paper towel, and a surface of the measurement sample was rubbed
with a hand, followed by evaluation according to the following
evaluation criteria.
[0064] Evaluation Criteria
[0065] A: No slimy feeling was felt.
[0066] B: No cobwebbing occurred but slimy feeling was felt.
[0067] C: Slimy feeling was felt and cobwebbing occurred.
(8) Friction Physical Property
[0068] Sheets or films of the resin compositions obtained in
examples and comparative examples were each cut into 2 cm
(W).times.5 cm (L), and these were used as measurement samples.
[0069] After 30 seconds from dropping 0.2 mL of ion exchange water
onto a coating surface of each of the measurement sample, the
coefficient of friction .mu. was monitored using a friction tester
(Model: KES-SE, manufactured by KATO TECH CO., LTD.) under the
following test conditions.
[0070] Sensor: silicone
[0071] Load: 50 [g]
[0072] Speed: 5 [mm/sec]
(i) Mean Coefficient of Friction (MIU)
[0073] The mean coefficient of friction has correlation with ease
of slipping or resistance to slipping when rubbing the surface. The
larger the value is, the more difficult the surface is to slip.
[0074] A schematic view of obtaining a mean coefficient of friction
(MIU) from the monitored result of the coefficient of friction .mu.
is shown in FIG. 1.
[0075] As shown in FIG. 1, a surface of a measurement sample is
scanned to monitor the coefficient of friction .mu. of a surface.
Then, the coefficient of friction .mu. is integrated at a monitored
width of 20 mm (shadow area of FIG. 1). By dividing the integrated
value by the monitored width (20 mm), the mean coefficient of
friction (MIU) is obtained.
[0076] When the value of MIU is 0.3 or less, it can be said that
the slipping property is good.
(ii) Deviation in Mean Coefficient of Friction (MMD)
[0077] The deviation in mean coefficient of friction has
correlation with smoothness and roughness when rubbing the surface.
The larger this value is, the rougher the surface is.
[0078] A schematic view of obtaining a deviation in mean
coefficient of friction (MMD) from the monitored result of the
coefficient of friction is shown in FIG. 2
[0079] As shown in FIG. 2, an absolute value of a difference
between the mean coefficient of friction (MIU) and the coefficient
of friction .mu. is integrated at a monitored width of 20 mm
(shadow area of FIG. 2). A deviation in mean coefficient of
friction (MMD) is obtained by dividing the integrated value by the
monitored width (20 mm).
[0080] When the value of MMD is 0.015 or less, it can be said that
the smoothness of the surface is good.
(iii) Repetition Test
[0081] After first monitoring, water on a surface was wiped with a
paper towel, and a sheet or a film was placed in an oven set at
50.degree. C. to dry. Then, second monitoring was performed under
the same conditions as described above. Similarly, the monitoring
was repeated up to 6 times, and the coefficient of friction .mu.
was monitored.
(9) Drug Release Amount
[0082] A sheet or a film of the resulting resin composition was cut
into a rectangular shape of 2 cm (W).times.5 cm (L).times.0.1 cm
(T) (mass: 1.0 g), and immersed in 10 g of water for a
predetermined time (10, 20, 30, and 60 minutes).
[0083] The water (4.5 mL) after the sheet or the film was taken out
was placed in quartz glass having a thickness of 1 cm and the
absorbance at a wavelengths of 289 nm was measured using an
ultraviolet-visible spectrophotometer (Model: UV-3150, manufactured
by Shimadzu Corporation). Using the resulting absorbance, the
amount of extracted ascorbic acid was calculated from a calibration
curve of ascorbic acid which had been measured in advance under the
same conditions.
Production Example 1
Method for Producing Water-Absorbing Modified Polyalkylene
Oxide
[0084] A storage tank A equipped with a stirrer and held at
80.degree. C. was charged with 100 parts by mass of a fully
dehydrated polyethylene oxide having a number average molecular
weight of 20,000, 0.90 parts by mass of 1,4-butanediol and 0.1
parts by mass of dioctyltin dilaurate, followed by stirring under a
nitrogen gas atmosphere to obtain a uniform mixture. Separately, a
storage tank B held at 30.degree. C. was charged with
dicycrohexylmethane-4,4'-diisocyanate and the tank was stored under
a nitrogen gas atmosphere.
[0085] Using a metering pump, the mixture of the storage tank A was
continuously supplied at a rate of 500 [g/min] and
dicyclohexylmetahane-4,4'-disisocyanate of the storage tank B was
continuously supplied at a rate of 19.4 [g/min] to a twin-screw
extruder set at 110 to 140.degree. C. (R value=1.00), the materials
were mixed in the extruder to perform a reaction, a strand was
discharged through an opening of the extruder, and pelletized with
a pelletizer to obtain a water-absorbing modified polyalkylene
oxide.
[0086] The resulting water-absorbing modified polyalkylene oxide
had a water absorption ability of 25 [g/g], a proportion of
water-soluble component of 15.5 [mass %], and a melt viscosity of
320 [Pas].
Production Example 2
Method for Producing Water-Absorbing Modified Polyalkylene
Oxide
[0087] An ethylene oxide/propylene oxide (mass ratio: 90/10)
copolymer having a number average molecular weight of 15,000 was
supplied at a rate of 250 [g/min] and ethylene glycol heated to
40.degree. C. was supplied at a rate of 2.1 [g/min] to a 40
mm-diameter single-screw extruder (L/D=40, preset temperature:
90.degree. C.), respectively, which were then melt-mixed.
[0088] The mixture obtained from a discharging opening (the mixture
was discharged in a uniform, molten state, and it was confirmed by
LC analysis that the materials were mixed in a charged ratio) was
continuously supplied to a hopper port (preset temperature:
80.degree. C.) of a 30 mm-diameter twin-screw extruder (L/D=41.5).
At the same time, dioctyltin dilaurate was supplied to the hopper
port of the twin-screw extruder at a rate of 0.5 [g/min].
[0089] Separately, dicyclohexylmethane-4,4'-diisocyanate adjusted
to 30.degree. C. was supplied to a screw barrel section situated on
a downstream side of the hopper port of the twin-screw extruder at
a rate of 12.4 [g/min] (R value=0.95) and a reaction was carried
out continuously under a nitrogen atmosphere (preset temperature:
180.degree. C.). A strand obtained from an opening of the
twin-screw extruder was cooled, and then pelletized with a
pelletizer to obtain a water-absorbing modified polyalkylene
oxide.
[0090] The resulting water-absorbing modified polyalkylene oxide
had a water absorption ability of 20 [g/g], a proportion of
water-soluble component of 11.3 [mass %], and a melt viscosity of
150 [Pas].
Production Example 3
Method for Producing Water-Soluble Modified Polyalkylene Oxide
[0091] A polyethylene oxide having a number average molecular
weight of 20,000 was supplied to a 40 mm-diameter single-screw
extruder (L/D=40, preset temperature: 90.degree. C.) at a rate of
250 [g/min] and molten.
[0092] The melt obtained from a discharge port was continuously
supplied to a hopper port (preset temperature: 80.degree. C.) of a
30 mm-diameter twin-screw extruder (L/D=41.5). At the same time,
dioctyltin dilaurate was supplied to the hopper port of the
twin-screw extruder at a rate of 0.25 [g/min].
[0093] Separately, dicyclohexylmethane-4,4'-diisocyanate adjusted
to 30.degree. C. was supplied to a screw barrel section situated on
a downstream side of the hopper port of the twin-screw extruder at
a rate of 3.27 [g/min] (R value=1.00) and a reaction was carried
out continuously under a nitrogen atmosphere (preset temperature:
180.degree. C.). A strand obtained from an opening of the
twin-screw extruder was cooled, and then pelletized with a
pelletizer to obtain a water-soluble modified polyalkylene
oxide.
[0094] The resulting water-absorbing modified polyalkylene oxide
had a proportion of water-soluble component of 100 [mass %] and a
melt viscosity of 220 [Pas]. Since the resulting modified
polyalkylene oxide was water-soluble, the water absorption ability
could not be measured.
Production Example 4
Method for Producing Cross-Linked Polyacrylate
[0095] To a 1 L four-necked cylindrical round-bottom flask equipped
with a stirrer, a reflux condenser and a nitrogen gas inlet tube
was added 550 mL of n-heptane. In this was added and dispersed 1.38
g of hexaglyceryl monobeherate (surfactant: NONION GV-106
manufactured by NOF Corporation) having an HLB of 13.1, and the
temperature was raised to 50.degree. C. to dissolve the surfactant,
followed by cooling to 30.degree. C.
[0096] Meanwhile, a 500 mL Erlenmeyer flask was separately
prepared, and 92 g of a 80 mass % aqueous acrylic acid solution was
added thereto. To this was added dropwise 152.6 g of a 20.1 mass %
aqueous sodium hydroxide solution while cooling from the outside to
perform neutralization of 75 mol %, thereafter, 0.11 g of potassium
persulfate and 0.019 g of ethylene glycol diglycidyl ether as a
crosslinking agent were further added and dissolved. Thereby, an
aqueous solution of partially neutralized acrylic acid was
obtained.
[0097] Then, the whole of the aqueous solution of partially
neutralized acrylic acid was added and dispersed in the four-necked
cylindrical round bottom flask, the system was replaced with
nitrogen, the temperature was raised, and a polymerization reaction
was performed over 3 hours while the temperature of the bath was
retained at 70.degree. C.
[0098] After completion of the polymerization reaction, a slurry
containing the resulting cross-linked polyacrylate was dried at
120.degree. C. for 2 hours to obtain 191.2 g of a cross-linked
polyacrylate.
[0099] The resulting cross-linked polyacrylate had a water
absorption ability of 550 [g/g] and a proportion of water-soluble
component of 0.06 [%]. The melt viscosity of the resulting
cross-linked polyacrylate could not be measured.
Example 1
[0100] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1 and 15 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, melt index (MI)=6, HDD=35] were supplied to a 28
mm-diameter twin-screw extruder (L/D=40) set at 130.degree. C. to
obtain a resin composition. The compositional ratio of the resin
composition is shown in Table 1.
[0101] The resulting resin composition was molded into a 6 cm
(W).times.9 cm (L).times.0.15 cm (T) sheet of the resin composition
using an injection-molding machine (Model: TI80G2, manufactured by
Toyo Machinery and Metal Co., Ltd.) set at 130 to 150.degree.
C.
[0102] The resulting sheet of the resin composition was cut into a
predetermined size and the above-described various measurements and
evaluations were performed. The results are shown in Table 2.
Example 2
[0103] 7 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1 and 14 [kg/hr] of an
ethylene/acrylic acid copolymer [abbreviation: EAA, manufactured by
Dow Chemical: Primacor 5980, acrylic acid content=20%, MI=300,
HDD=40] were supplied to a 28 mm-diameter twin-screw extruder
(L/D=40) set at 140.degree. C. to obtain a resin composition. The
compositional ratio of the resin composition is shown in Table
1.
[0104] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 130.degree.
C.
[0105] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Example 3
[0106] 10 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Product Example 2 and 10 [kg/hr] of an
ethylene/acrylic acid copolymer [abbreviation: EAA, manufactured by
Dow Chemical: Primacor 3460, acrylic acid content=9.7%, MI=20,
HDD=42] were supplied to a 28 mm-diameter twin-screw extruder
(L/D=40) set at 130.degree. C. to obtain a resin composition. The
compositional ratio of the resin composition is shown in Table
1.
[0107] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 130.degree.
C.
[0108] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Example 4
[0109] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Product Example 1, 12 [kg/hr] of an ethylene/vinyl
acetate copolymer [abbreviation: EVA, manufactured by Sumitomo
Chemical Co., Ltd.: Evatate D2010, vinyl acetate content=25%, MI=3,
HDD=28], and 3 [kg/hr] of an ethylene/acrylic acid copolymer
[abbreviation: EAA, manufactured by Dow Chemical: Primacor 3460,
acrylic acid content=9.7%, MI=20, HDD=42] were supplied to a 28
mm-diameter twin-screw extruder (L/D=40) set at 140.degree. C.,
respectively, to obtain a resin composition. The compositional
ratio of the resin composition is shown in Table 1.
[0110] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (Gonno Hydraulic Press, 40 t press,
pressure: 50 [kg/cm.sup.2]) set at 130.degree. C.
[0111] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Example 5
[0112] 5 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 2 and 8 [kg/hr] of an
ethylene/ethyl acrylate copolymer [abbreviation: EEA, manufactured
by Nippon Unicar Company Limited: NUC-6170, ethyl acrylate
content=18%, MI=6, HDD=31] were supplied to a 28 mm-diameter
twin-screw extruder (L/D=40) set at 150.degree. C. to obtain a
resin composition. The compositional ratio of the resin composition
is shown in Table 1.
[0113] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (Gonno Hydraulic Manufacturing Co.,
Ltd, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 150.degree.
C.
[0114] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Example 6
[0115] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1, 15 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, melt index (MI)=6, HDD 35], and 42 [g/hr] of ascorbic
acid were supplied to a 28 mm-diameter twin-screw extruder (L/D=40)
set at 130.degree. C. to obtain a resin composition.
[0116] The resulting resin composition was processed into an
inflation film having a width of 160 mm and a thickness of 80 .mu.m
using an extruder (SYH25-25 manufactured by Silicone Machinery,
L/D=25) set at 130 to 150.degree. C. and an inflation molding
machine (SF-300 manufactured by Silicone Machinery).
[0117] The resulting inflation film was cut into a predetermined
size, and the above-described various measurements and evaluations
were performed. The results are shown in Table 2.
Example 7
[0118] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1, 15 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, melt index (MI)=6, HDD=35] and 42 [g/hr]
(corresponding to 0.2 parts by mass based on 100 parts by mass of a
resin composition) of ascorbic acid were supplied to a 28
mm-diameter twin-screw extruder (L/D=40) set at 130.degree. C. to
obtain a resin composition. The compositional ratio of the resin
composition is shown in Table 1.
[0119] The resulting resin composition was molded into a 6 cm
(W).times.9 cm (L).times.0.15 cm (T) sheet of the resin composition
using an injection molding machine (Model: TI80G2, manufactured by
Toyo Machinery and Metal Co., Ltd.) set at 130 to 150.degree.
C.
[0120] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Tables 2
and 3.
Comparative Example 1
[0121] 15 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1 and 3 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, MI=6, HDD=35] were supplied to a 28 mm-diameter
twin-screw extruder (L/D=40) set at 120.degree. C. to obtain a
resin composition. The compositional ratio of the resin composition
is shown in Table 1.
[0122] The resulting resin composition was molded into a 6 cm
(W).times.9 cm (L).times.0.15 cm (T) sheet of the resin composition
using an injection molding machine (Model: TI80G2, manufactured by
Toyo Machinery and Metal Co., Ltd.) set at 130 to 150.degree.
C.
[0123] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 2
[0124] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1 and 15 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by DuPont-Mitsui Polychemical Co., Ltd.: Evaflex EV45LX, vinyl
acetate content=46%, MI=2.5, HDD=8] were supplied to a 28
mm-diameter twin-screw extruder (L/D=40) set at 140.degree. C. to
obtain a resin composition. The compositional ratio of the resin
composition is shown in Table 1.
[0125] The resulting resin composition was molded into a 6 cm
(W).times.9 cm (L).times.0.15 cm (T) sheet of the resin composition
using an injection molding machine (Model: TI80G2, manufactured by
Toyo Machinery and Metal Co., Ltd.) set at 130 to 150.degree.
C.
[0126] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 3
[0127] 6 [kg/hr] of a water-soluble polyethylene oxide (Model:
PEO8Z, manufactured by Sumitomo Seika Chemicals Co., Ltd.,
viscosity average molecular weight: 2,000,000) and 15 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, MI=6, HDD=35] were supplied to a 28 mm-diameter
twin-screw extruder (L/D=40) set at 220.degree. C. to obtain a
resin composition. The compositional ratio of the resin composition
is shown in Table 1.
[0128] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 130.degree.
C.
[0129] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 4
[0130] 6 [kg/hr] of a water-soluble modified polyalkylene oxide
obtained as in Production Example 3 and 12 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, MI=6, HDD=35] were supplied to a 28 mm-diameter
twin-screw extruder (L/D=40) set at 130.degree. C. to obtain a
resin composition. The compositional ratio of the resin composition
is shown in Table 1.
[0131] The resulting resin composition was molded into a 6 cm
(W).times.9 cm (L).times.0.15 cm (T) sheet of the resin composition
using an injection molding machine (Model: TI80G2, manufactured by
Toyo Machinery and Metal Co., Ltd.) set at 130 to 150.degree.
C.
[0132] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 5
[0133] 2 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 2 and 18 [kg/hr] of an
ethylene/acrylic acid copolymer [abbreviation: EAA, manufactured by
Dow Chemical: Primacor 3460, acrylic acid content=9.7%, MI=20,
HDD=42] were supplied to a 28 mm-diameter twin-screw extruder
(L/D=40) set at 130.degree. C. to obtain a resin composition. The
compositional ratio of the resin composition is shown in Table
1.
[0134] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 130.degree.
C.
[0135] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 6
[0136] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1 and 15 [kg/hr] of a high impact
polystyrene [abbreviation: HIPS, manufactured by BASF: 476L,
HDD=72] were supplied to a 28 mm-diameter twin-screw extruder
(L/D=40) set at 220.degree. C. to obtain a resin composition. The
compositional ratio of the resin composition is shown in Table
1.
[0137] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 220.degree.
C.
[0138] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 7
[0139] 6 [kg/hr] of a cross-linked polyacrylate obtained in
Production Example 4 and 15 [kg/hr] of an ethylene/vinyl acetate
copolymer [abbreviation: EVA: manufactured by Sumitomo Chemical
Co., Ltd.: Evatate D3010, vinyl acetate content=10%, MI=6, HDD=35]
were supplied to a 28 mm-diameter twin-screw extruder (L/D=40) set
at 120.degree. C. to obtain a resin composition. The compositional
ratio of the resin composition is shown in Table 1.
[0140] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.10 cm (T) sheet of the resin
composition using a hot press (manufactured by Gonno Hydraulic
Press, 40 t press, pressure: 50 [kg/cm.sup.2]) set at 130.degree.
C.
[0141] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Table
2.
Comparative Example 8
[0142] 15 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtain as in Production Example 1 and 3 [kg/hr] of an
ethylene/vinyl acetate copolymer [abbreviation: EVA, manufactured
by Sumitomo Chemical Co., Ltd.: Evatate D3010, vinyl acetate
content=10%, MI=6, HDD=35] were supplied to a 28 mm-diameter
twin-screw extruder (L/D=40) set at 120.degree. C. to obtain a
resin composition. The compositional ratio of the resin composition
is shown in Table 1.
[0143] The resulting resin composition was processed into an
inflation film having a width of 160 mm and a thickness of 80 .mu.m
using an extruder (SYH25-25, L/D=25, manufactured by Silicone
Machinery) set at 130 to 150.degree. C. and an inflation molding
machine (SF-300 manufactured by Silicone Machinery).
[0144] The resulting inflation film was cut into a predetermined
size, and the above-described various measurements and evaluations
were performed. The results are shown in Table 2.
Comparative Example 9
[0145] 6 [kg/hr] of a water-absorbing modified polyalkylene oxide
obtained as in Production Example 1, 15 [kg/hr] of a high impact
polystyrene [abbreviation: HIPS, manufactured by BASF: 476L,
HDD=72] and 42 [g/hr] (corresponding to 0.2 parts by mass based on
100 parts by mass of a resin composition) of ascorbic acid were
supplied to a 28 mm-diameter twin-screw extruder (L/D=40) set at
220.degree. C. to obtain a resin composition. The compositional
ratio of the resin composition is shown in Table 1.
[0146] The resulting resin composition was molded into a 10 cm
(W).times.10 cm (L).times.0.1 cm (T) sheet of the resin composition
using a hot press (manufactured by Gonno Hydraulic Press, 40 t
press, pressure: 50 [kg/cm.sup.2]) set at 220.degree. C.
[0147] The resulting sheet of the resin composition was cut into a
predetermined size, and the above-described various measurements
and evaluations were performed. The results are shown in Tables 2
and 3.
TABLE-US-00001 TABLE 1 Modified polyalkylene oxide Different resin
Thermoplastic resin Supply amount Supply amount Supply amount Kind
[kg/hr] Kind [kg/hr] Kind HDD [kg/hr] [Parts by mass]*.sup.)
Thickness Example 1 Production 6 -- -- EVA 35 15 250 0.15 cm
Example 1 Example 2 Production 7 -- -- EAA 40 14 200 0.10 cm
Example 1 Example 3 Production 10 -- -- EAA 42 10 100 0.10 cm
Example 2 Example 4 Production 6 -- -- EVA 28 12 250 0.10 cm
Example 1 EAA 42 3 Example 5 Production 5 -- -- EEA 31 8 160 0.10
cm Example 2 Example 6 Production 6 -- -- EVA 35 15 250 80 .mu.m
Example 1 Example 7 Production 6 -- -- EVA 35 15 250 0.10 cm
Example 1 Comparative Production 15 -- -- EVA 35 3 20 0.15 cm
Example 1 Example 1 Comparative Production 6 EVA 8 15 250 0.15 cm
Example 2 Example 1 Comparative -- -- PEO8Z 6 EVA 35 15 250 0.10 cm
Example 3 Comparative Production 6 -- -- EVA 35 12 200 0.15 cm
Example 4 Example 3 Comparative Production 2 -- -- EAA 42 18 900
0.10 cm Example 5 Example 2 Comparative Production 6 -- -- HIPS 72
15 250 0.10 cm Example 6 Example 1 Comparative -- -- Production 6
EVA 35 15 250 0.10 cm Example 7 Example 4 Comparative Production 15
-- -- EVA 35 3 20 80 .mu.m Example 8 Example 1 Comparative
Production 6 -- -- HIPS 72 15 250 0.10 cm Example 9 Example 1
*.sup.)Parts by mass of a thermoplastic resin, letting a
water-absorbing modified polyalkylene oxide or a different resin to
be 100 parts by mass
TABLE-US-00002 TABLE 2 Friction physical property Mean coefficient
Deviation in mean Swelling of friction coefficient of Bending test
ratio (MIU) friction (MMD) 90 degrees 180 degrees [%] Slimy feeling
First time 6.sup.th time First time 6.sup.th time Example 1 A A 180
A 0.18 0.22 0.009 0.014 Example 2 A A 220 A 0.16 0.18 0.011 0.015
Example 3 A A 250 A 0.11 0.16 0.009 0.013 Example 4 A A 190 A 0.09
0.21 0.009 0.012 Example 5 A A 280 A 0.14 0.17 0.010 0.014 Example
6 A A 150 A 0.18 0.22 0.009 0.014 Example 7 A A 180 A 0.18 0.22
0.009 0.014 Comparative B C 560 A 0.15 0.35 0.014 0.017 Example 1
Comparative C C 250 B 0.21 0.31 0.013 0.016 Example 2 Comparative B
C 190 C 0.75 0.81 0.069 0.089 Example 3 Comparative A A 250 B 0.38
0.82 0.076 0.097 Example 4 Comparative A A 50 A 0.41 0.74 0.087
0.088 Example 5 Comparative C C 190 A 0.28 0.59 0.009 0.001 Example
6 Comparative A A Gel A 0.67 0.77 0.098 0.115 Example 7 desorption
Comparative B C 150 A 0.15 0.35 0.014 0.017 Example 8 Comparative C
C 190 A 0.28 0.59 0.087 0.088 Example 9
[0148] As is apparent from the results shown in Table 2, the resin
composition of the present invention containing 100 parts by mass
of a water-absorbing modified polyalkylene oxide and 60 to 500
parts by mass of a thermoplastic resin having a type D durometer
hardness (HDD) of 10 to 60 has small change in dimension due to
swelling, maintains its lubricity even if used repeatedly, has no
slimy feeling, and has flexibility.
TABLE-US-00003 TABLE 3 Immersion time Drug release amount [min]
[mg] [mass %]*.sup.) Example 7 10 0.6 30 20 0.7 35 30 0.8 40 60 1.1
55 Comparative 10 0 0 Example 9 20 0 0 30 0 0 60 0 0 *.sup.)Amount
(mass %) of release of 2 mg (amount contained in 1 g of sheet of
resin composition) of ascorbic acid in water
[0149] As is apparent from the results shown in Table 3, it can be
understood that the resin composition of the present invention
containing 100 parts by mass of a water-absorbing modified
polyalkylene oxide, 60 to 500 parts by mass of a thermoplastic
resin having a type D durometer hardness (HDD) of 10 to 60, and
ascorbic acid (drug) can efficiently release ascorbic acid into
water without degradation by heat.
[0150] On the other hand, it can be understood that the resin
composition of Comparative Example 8 cannot release the added
ascorbic acid in water because of degradation by heat, since it
necessitates a high temperature in the production stage.
INDUSTRIAL APPLICABILITY
[0151] Since the resin composition of the present invention
maintains its lubricity even if used repeatedly, has no slimy
feeling, and has flexibility, it can be optimally used widely in
the field requiring lubricity under wet conditions, for example, a
wet shaving instrument represented by a razor, and medical
instruments such as a catheter.
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