U.S. patent application number 14/928230 was filed with the patent office on 2016-05-12 for ink, ink cartridge, inkjet recording device, and copolymer.
The applicant listed for this patent is Masayuki FUKUOKA, Shigeyuki HARADA, Keita KATOH, Yuusuke KOIZUKA, Kazukiyo NAGAI, Akiyoshi SABU, Tomoyuki SHIMADA, Yoshiki YANAGAWA. Invention is credited to Masayuki FUKUOKA, Shigeyuki HARADA, Keita KATOH, Yuusuke KOIZUKA, Kazukiyo NAGAI, Akiyoshi SABU, Tomoyuki SHIMADA, Yoshiki YANAGAWA.
Application Number | 20160130452 14/928230 |
Document ID | / |
Family ID | 55911723 |
Filed Date | 2016-05-12 |
United States Patent
Application |
20160130452 |
Kind Code |
A1 |
KATOH; Keita ; et
al. |
May 12, 2016 |
INK, INK CARTRIDGE, INKJET RECORDING DEVICE, AND COPOLYMER
Abstract
An ink includes water, a pigment, and a copolymer, wherein the
copolymer contains a structure unit represented by the following
Chemical formula 1, ##STR00001## where R.sub.1 represents a
hydrogen atom or a methyl group, M.sub.1.sup.+ and M.sub.2.sup.+
each, independently represent monovalent cations, n and m each,
independently represent 0 or integers of from 1 to 6 excluding a
case where both are 0 and a structure unit represented by the
following Chemical formula 2, ##STR00002## where R.sub.2 represents
a hydrogen atom or a methyl group, Y represents an alkylene group
having 2 to 18 carbon atoms.
Inventors: |
KATOH; Keita; (Kanagawa,
JP) ; HARADA; Shigeyuki; (Shizuoka, JP) ;
YANAGAWA; Yoshiki; (Shizuoka, JP) ; FUKUOKA;
Masayuki; (Shizuoka, JP) ; NAGAI; Kazukiyo;
(Shizuoka, JP) ; SHIMADA; Tomoyuki; (Shizuoka,
JP) ; SABU; Akiyoshi; (Shizuoka, JP) ;
KOIZUKA; Yuusuke; (Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KATOH; Keita
HARADA; Shigeyuki
YANAGAWA; Yoshiki
FUKUOKA; Masayuki
NAGAI; Kazukiyo
SHIMADA; Tomoyuki
SABU; Akiyoshi
KOIZUKA; Yuusuke |
Kanagawa
Shizuoka
Shizuoka
Shizuoka
Shizuoka
Shizuoka
Shizuoka
Shizuoka |
|
JP
JP
JP
JP
JP
JP
JP
JP |
|
|
Family ID: |
55911723 |
Appl. No.: |
14/928230 |
Filed: |
October 30, 2015 |
Current U.S.
Class: |
347/20 ; 347/86;
524/547; 526/278 |
Current CPC
Class: |
C09D 11/107 20130101;
C08F 220/343 20200201; C08F 220/343 20200201; C08F 220/34 20130101;
C09D 11/322 20130101; C09D 133/14 20130101; C08F 220/58 20130101;
C08F 230/02 20130101; C08F 230/02 20130101; C08F 220/58 20130101;
C09D 11/326 20130101 |
International
Class: |
C09D 11/30 20060101
C09D011/30; C09D 133/14 20060101 C09D133/14; C08F 222/10 20060101
C08F222/10 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2014 |
JP |
2014-229638 |
Claims
1. An ink comprising: water; a pigment; and a copolymer, wherein
the copolymer comprises a structure unit represented by the
following Chemical formula 1, ##STR00020## where R.sub.1 represents
a hydrogen atom or a methyl group, M.sub.1.sup.+ and M.sub.2.sup.+
each, independently represent monovalent cations, n and m each,
independently represent 0 or integers of from 1 to 6 excluding a
case where both are 0 and a structure unit represented by the
following Chemical formula 2, ##STR00021## where R.sub.2 represents
a hydrogen atom or a methyl group and Y represents an alkylene
group having 2 to 18 carbon atoms.
2. The ink according to claim 1, wherein a molar ratio of the
structure unit represented by the Chemical formula 1 to the
structure unit represented by the Chemical formula 2 is from 0.5 to
3.
3. The ink according to claim 1, wherein Y is an alkylene group
having 2 to 12 carbon atoms.
4. The ink according to claim 1, wherein the copolymer is
synthesized by copolymerizing a monomer represented by the
following Chemical formula 3 and a monomer represented by the
following Chemical formula 4, ##STR00022##
5. The ink according to claim 1, wherein the copolymer further
includes a structure unit represented by the following Chemical
formula 5, wherein R.sub.3 represents a hydrogen atom or a methyl
group, ##STR00023##
6. The ink according to claim 5, wherein a molar ratio of the
structure unit represented by the Chemical formula 5 to the
structure unit represented by the Chemical formula 2 is from 0.1 to
4.
7. The ink according to claim 1, further comprising at least one of
a water soluble organic solvent or a surfactant.
8. An ink cartridge comprising: a container to contain the ink of
claim 1.
9. An inkjet recording device comprising: a discharging device to
discharge the ink of claim 1.
10. A copolymer comprising: a structure unit represented by the
following Chemical formula 1 ##STR00024## where R.sub.1 represents
a hydrogen atom or a methyl group, M.sub.1.sup.+ and M.sub.2.sup.+
each, independently represent monovalent cations, n and m each,
independently represent 0 or integers of from 1 to 6 excluding a
case where both are 0 and a structure unit represented by the
following Chemical formula 2, ##STR00025## where R.sub.2 represents
a hydrogen atom or a methyl group and Y represents an alkylene
group having 2 to 18 carbon atoms.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is based on and claims priority
pursuant to 35 U.S.C. .sctn.119(a) to Japanese Patent Application
No. 2014-229638 filed on Nov. 12, 2014, in the Japan Patent Office,
the entire disclosures of which are hereby incorporated by
reference herein.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to ink, an ink cartridge, an
inkjet recording device, and a copolymer.
[0004] 2. Background Art
[0005] Inkjet recording methods are advantageous in comparison with
other recording methods in that the process is simple, full
colorization is easy, and high resolution images can be obtained by
a device having a simple configuration. For this reason, the inkjet
recording is widely diffusing from home use to office use,
commercial printing, and industrial printing.
[0006] For office use, typically plain paper is used as a recording
medium and high image density is demanded.
[0007] In addition, in the commercial printing and industrial
printing, other kinds of paper such as coated paper and art paper
are also used.
[0008] In such an inkjet recording method, mostly aqueous ink using
water soluble dye as a colorant is used. However, its water
resistance and light resistance are inferior, which accelerates
development of a pigment ink using a water insoluble pigment in
place of the water soluble dye.
[0009] In general, when images are printed on plain paper using
pigment ink, the pigment ink permeates into the paper, so that the
pigment density on the surface decreases, thereby lowering the
image density. If the pigment concentration in the pigment ink
increases, the image density increases. However, the pigment ink
becomes viscous, thereby degrading discharging stability of the
ink.
SUMMARY
[0010] According to the present disclosure, provided is an improved
ink that includes water, a pigment, and a copolymer, wherein the
copolymer contains a structure unit represented by the following
Chemical formula 1,
##STR00003##
[0011] where R.sub.1 represents a hydrogen atom or a methyl group,
M.sub.1.sup.+ and M.sub.2.sup.+ each, independently represent
monovalent cations, n and m each, independently represent 0 or
integers of from 1 to 6 excluding a case where both are 0 and a
structure unit represented by the following Chemical formula 2,
##STR00004##
[0012] where R.sub.2 represents a hydrogen atom or a methyl group
and Y represents an alkylene group having 2 to 18 carbon atoms.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] Various other objects, features and attendant advantages of
the present invention will be more fully appreciated as the same
become better understood from the detailed description when
considered in connection with the accompanying drawings, in which
like reference characters designate like corresponding parts
throughout and wherein
[0014] FIG. 1 is a diagram illustrating an example of the ink
cartridge;
[0015] FIG. 2 is a graph illustrating an IR spectrum of the
compound represented by Chemical formula 4-1;
[0016] FIG. 3 is a graph illustrating an IR spectrum of a precursor
of a copolymer 1-1 described later;
[0017] FIG. 4 is a graph illustrating an IR spectrum of a precursor
of a copolymer 1-10 described later;
[0018] FIG. 5 is a graph illustrating an IR spectrum of a precursor
of a copolymer 2-1 described later; and
[0019] FIG. 6 is a graph illustrating an IR spectrum of a precursor
of a copolymer 2-10 described later.
DETAILED DESCRIPTION
[0020] The ink of the present disclosure has excellent storage
stability, discharging stability, and image density on plain paper
so that occurrence of beading of images formed on coated paper is
inhibited by using the ink of the present disclosure.
[0021] Embodiments of the present disclosure are described with
reference to accompanying drawings.
[0022] The ink of the present disclosure includes a structure unit
represented by Chemical formula 1 and a structure unit represented
by Chemical formula 2.
##STR00005##
[0023] where R.sub.1 represents a hydrogen atom or a methyl group,
M.sub.1.sup.+ and M.sub.2.sup.+ each, independently represent
monovalent cations, n and m each, independently represent 0 or
integers of from 1 to 6 excluding a case where both are 0.
##STR00006##
[0024] where R.sub.2 represents a hydrogen atom or a methyl group,
Y represents an alkylene group having 2 to 18 carbon atoms.
[0025] The group represented by the following Chemical formula 1-1
in the Chemical formula 1 indicates hydrophilicity but becomes
hydrophobic in reaction with a multi-valent metal ion such as
calcium ion, magnesium ion, and aluminum ion.
##STR00007##
[0026] Therefore, if ink containing the copolymer having the
structure unit represented by the Chemical formula 1 as a binder
resin or a pigment dispersant is attached to a recording medium
containing salts (such as calcium carbonate) of the metal ions
mentioned above, the copolymer becomes hydrophobic in the reaction
with the multi-valent metal ions eluted from the recording medium.
As a result, the ink is thickened and the pigment agglomerates.
Consequently, permeation of the pigment into the recording medium
is inhibited. This makes it possible to improve the image density
on plain paper and also reduce occurrences of beading when forming
images on coated paper.
[0027] The number of the carbon atoms of Y in the Chemical formula
2 is preferably from 2 to 16 and more preferably from 2 to 12.
[0028] The naphthyl group in the Chemical formula 2 is strongly
adsorbed with a pigment due to .pi.-.pi. stacking with the pigment.
This contributes to improvement of storage stability, discharging
stability, the image density on plain paper and also reduction of
occurrences of beading when forming an image on coated paper. Since
the rate of the copolymer isolated in the ink decreases, increase
of the viscosity of the ink due to evaporation of water can be
inhibited, thereby improving discharging stability.
[0029] In addition, it is possible to increase storage stability of
the ink by using the copolymer including the structure unit
represented by the Chemical formula 2 when dispersing the pigment
in water.
[0030] The structure units represented by the Chemical formula 1
and Chemical formula 2 usually form the main chain of the copolymer
but part of the units may be a side chain of the copolymer. For
example, it is well known that it is difficult to completely
exclude additional radical polymerization reaction that produces
fork structures.
[0031] The molar ratio of the structure unit represented by the
Chemical formula 1 to the structure unit represented by the
Chemical formula 2 is 0.1 to 10, preferably from 0.3 to 5, and more
preferably from 0.5 to 3. When the molar ratio of the structure
unit represented by the Chemical formula 1 to the structure unit
represented by the Chemical formula 2 is not less than 0.5, the
image density is improved. When the molar ratio of the structure
unit represented by the Chemical formula 1 to the structure unit
represented by the Chemical formula 2 is not greater than 3,
storage stability is improved.
[0032] The content of the structure unit represented by Chemical
formula 1 in the copolymer is from 5 percent by mass to 83 percent
by mass, preferably from 13 percent by mass to 71 percent by mass,
and more preferably from 20 percent by mass to 60 percent by
mass.
[0033] The mono-valent cation in M.sub.1.sup.+ and M.sub.2.sup.+ is
not particularly limited. Specific examples thereof include, but
are not limited to, proton, sodium ion, potassium ion, lithium ion,
tetramethyl ammonium ion, tetraethyl ammonium ion, tetrapropyl
ammonium ion, tetrabutyl ammonium ion, tetrapentyl ammonium ion,
tetrahexyl ammonium ion, triethylmethyl ammonium ion,
tributylmethyl ammonium ion, trioctylmethyl ammonium ion,
2-hydroxyethyl trimethyl ammonium ion, tris(2-hydroxyethyl)methyl
ammonium ion, propyltrimethyl ammonium ion, hexyltrimethyl ammonium
ion, octyltrimethyl ammonium ion, nonyltrimethyl ammonium ion,
decyltrimethyl ammonium ion, dodecyltrimerthyl ammonium ion,
tetradecyltrimethyl ammonium ion, hexadecyl trimethyl ammonium ion,
octadecyl trimethyl ammonium ion, didodecyl dimethyl ammonium ion,
ditetradecyl dimethyl ammonium ion, dihexyadecyl dimethyl ammonium
ion, dioctadecyl dimethyl ammonium ion, ethylhexadecyl dimethyl
ammonium ion, ammonium ion, dimethyl ammonium ion, trimethyl
ammonium ion, monoethyl ammonium ion, diethyl ammonium ion,
triethyl ammonium ion, monoethanol ammonium ion, diethanol ammonium
ion, triethanol ammonium ion, methyl ethanol ammonium ion,
methyldiethanol ammonium ion, dimethylethanol ammonium ion,
monopropanol ammonium ion, dipropanol ammonium ion, tripropanol
ammonium ion, isopropanol ammonium ion, morpholinium ion, N-methyl
morpholinium ion, N-methyl-2-pyrolidonium ion, and 2-pyrolidonium
ion.
[0034] When M.sub.1.sup.+ and/or M.sub.2.sup.+ is a proton, the
proton is not necessary disassociated.
[0035] The copolymer can be synthesized by copolymerizing the
monomer represented by the Chemical formula 3, the monomer
represented by the Chemical formula 4, and other optional monomers
followed by optional neutralization by a base.
##STR00008##
[0036] The compound represented by the Chemical formula 3 is not
particularly limited. Specific examples thereof include, but are
not limited to, 2-methacryloyloxy ethyl acid phosphate represented
by the Chemical formula 3-1,2-acryloyloxy ethyl acid phosphate
represented by the Chemical formula 3-2, acid phosphoxy
polyoxyethyleneglycol methacrylate represented by the Chemical
formula 3-3, acid phosphoxy polyoxypropyleneglycol methacrylate
represented by the Chemical formula 3-4, and acid phosphoxy
polyoxypoly(oxyethylene oxypropylene)glycol methacrylate
represented by the Chemical formula 3-5.
##STR00009##
[0037] Examples of the commercial products of 2-methacryloyloxy
ethyl acid phosphate available on market are LIGHT ESTER P1-M
(manufactured by Kyoeisha Chemical Co., Ltd.) and Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.).
[0038] An example of the commercial product of 2-acryloyloxy ethyl
acid phosphate available on market is LIGHT ACRYLATE P-1A
(manufactured by Kyoeisha Chemical Co., Ltd.).
[0039] An example of the commercial product of acid phosphoxy
polyoxyethyleneglycol methacrylate available on market is
Phosmer.TM. PE (manufactured by Uni-Chemical Co., Ltd.).
[0040] An example of the commercial product of acid phosphoxy
polyoxypropyleneglycol methacrylate available on market is
Phosmer.TM. PP (manufactured by Uni-Chemical Co., Ltd.).
[0041] An example of the commercial products of acid phosphoxy
poly(oxyethylene oxypropylene)glycol methacrylate is a known
compound disclosed in JP-2003-506536-A.
[0042] The compound represented by the Chemical formula 4 is not
particularly limited. Specific examples thereof include, but are
not limited to, the compound represented by the Chemical formula
4-1, the compound represented by the Chemical formula 4-2, the
compound represented by the Chemical formula 4-3, and the compound
represented by the Chemical formula 4-4
##STR00010##
[0043] The compound represented by the Chemical formula 4 has a
molecular weight in the range of from 357 to 596.
[0044] The compound represented by the Chemical formula 4 can be
synthesized by the condensation reaction 1 illustrated below of
naphthalene carbonyl chloride (A-1) with an excessive amount of
alkane diol (A-2) under the presence of an acid acceptor such as
amine and pyridine to obtain naphthalene carboxylic acid
hydroxyalkylester (A-3) followed by reaction with 2-methacyloyloxy
ethylisocyanate (A-4).
##STR00011##
[0045] The copolymer preferably further contains the structure unit
represented by the Chemical formula 5,
##STR00012##
[0046] where R.sub.3 represents a hydrogen atom or a methyl group.
The monomer optionally contains the compound represented by
Chemical formula 6.
##STR00013##
[0047] The structure unit represented by the Chemical formula 5 has
a high level of affinity with a water soluble organic solvent for
use in ink. Accordingly, dispersion of a pigment or a resin is
stable even when water in the ink evaporates so that the ratio of
the water soluble organic solvent in the ink increases. As a
consequence, discharging stability is further improved.
[0048] The molar ratio of the structure unit represented by the
Chemical formula 5 to the structure unit represented by the
Chemical formula 2 is in the range of from 0.1 to 6 and preferably
from 0.1 to 4. When the molar ratio of the structure unit
represented by the Chemical formula 5 to the structure unit
represented by the Chemical formula 2 is not less than 0.1,
discharging stability of ink is further enhanced. When the molar
ratio is not greater than 6, storage stability of the ink is
furthermore improved.
[0049] The structure unit represented by the Chemical formula 5
usually forms the main chain of the copolymer but part of the units
may be a side chain of the copolymer.
[0050] The compound represented by the Chemical formula 6 is not
particularly limited. Specific examples thereof include, but are
not limited to, diacetone acrylamide and diacetone
methacrylamide.
[0051] The viscosity of a 10 percent by mass aqueous solution of
the copolymer is in the range of from 1.0 mPas to 35.0 mPas and
preferably from 1.5 mPas to 25.0 mPas at 25 degrees C. When the
viscosity of the 10 percent by mass aqueous solution of the
copolymer is 1.0 mPas or higher at 25 degrees C., reactivity of the
metal ion eluted from plain paper and the copolymer ameliorates, so
that the image density on plain paper can be furthermore improved.
To the contrary, when the viscosity of the 10 percent by mass
aqueous solution of the copolymer is 35.0 mPas or less at 25
degrees C., the dispersion stability of the pigment is improved, so
that the storage stability of the ink is furthermore improved.
[0052] The copolymer furthermore optionally contains a structure
unit other than the structure units represented by the Chemical
formula 1, the Chemical formula 2, and the Chemical formula 5. In
this case, the monomer furthermore includes a polymerizable
hydrophobic monomer, a polymerizable hydrophilic monomer,
polymerizable surfactant, etc.
[0053] The polymerizable hydrophobic monomer is not particularly
limited. Specific examples thereof include, but are not limited to,
unsaturated ethylene monomers having aromatic ring such as styrene,
.alpha.-methyl styrene, 4-t-butyl styrene, and 4-chloromethyl
styrene; (meth)acrlic acid alkyl such as methyl(meth)acrylate,
ethyl(meth)acrylate, n-butyl(meth)acrylate, dimethyl maleate,
dimethyl itaconate, dimethyl fumarate, lauryl(meth)acrylate (C12),
tridecyl(meth)acrylate (C13), tetradecyl(meth)acrylate (C14),
pentadecyl(meth)acrylate (C15), hexadecyl(meth)acrylate (C16),
heptadecyl(meth)acrylate (C17), nonadecyl(meth)acrylate (C19),
eicosyl(meth)acrylate (C20), heneicosyl(meth)acrylate (C21), and
docosyl(meth)acrylate (C22); and unsaturated ethylene monomers
having an alkyl group such as 1-heptene, 3,3-dimethyl-1-pentene,
4,4-dimethyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1-hexene,
5-methyl-1-hexene, 1-octene, 3,3-dimethyl-1-hexene,
3,4-diemthyl-1-hexene, 4,4-diemthyl-1-hexene, 1-nonene,
3,5,5-trimethyl-1-hexene, 1-decene, 1-undecene, 1-dodecene,
1-tridecene, 1-tetracene, 1-pentadecene, 1-hexadecene,
1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicocene, and
1-dococene.
[0054] These may be used alone or in combination of two or more
thereof.
[0055] The polymerizable hydrophilic monomer is not particularly
limited. Specific examples thereof include, but are not limited to,
anionic unsaturated ethylene monomers of unsaturated ethylene
monomers such as maleic acid or salts thereof, monomethyl maleate,
itaconic acid, monomethyl itaconate, fumaric acid, 4-styrene
sulfonic acid, 2-acrylic amide-2-methyl propane sulfonic acid, or
anionic unsaturated ethylene monomers having phosphoric acid,
phosphonic acid, alendronic acid, or etidronic acid; and nonionic
unsaturated ethylene monomers such as 2-hydroxyethyl(meth)acrylic
acid, diethylene glycol mono(meth)acrylate, triethylene glycol
mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate,
polyethylene glycol mono(meth)acrylate, (meth)acrylamide,
N-methylol(meth)acrylamide, N-vinyl formamide, N-vinylacetoamide,
N-vinylpyrolidone, acrylamide, N,N-dimethyl acrylamide, N-t-butyl
acrylamide, N-octyl acrylamide, and N-t-octyl acrylamide.
[0056] These may be used alone or in combination of two or more
thereof.
[0057] The ratio of the total content of the polymerizable
hydrophobic monomer and the polymerizable hydrophilic monomer to
the total content of the compound having the structure units
represented by the Chemical formula 1 and the Chemical formula 2 is
in the range of from 0.05 to 1.
[0058] The polymerizable surfactant is an anionic or nonionic
surfactant having at least one radically-polymerizable unsaturated
double bond.
[0059] The polymerizable anionic surfactant is not particularly
limited. Specific examples thereof include, but are not limited to,
a compound having a sulfuric acid salt group such as ammonium
sulfate group (--SO.sub.3--NH.sub.4.sup.+) and an allyl group
(--CH.sub.2--CH.dbd.CH.sub.2), a compound having a sulfuric acid
salt group such as ammonium sulfate group
(--SO.sub.3--NH.sub.4.sup.+) and a methacyloyl group
[--CO--C(CH.sub.3).dbd.CH.sub.2], and a compound having a sulfuric
acid salt group such as ammonium sulfate group
(--SO.sub.3--NH.sub.4.sup.+) and a 1-propenyl group
(--CH.dbd.CH.sub.2CH.sub.3).
[0060] Examples of the polymerizable anionic surfactant available
on market are, ELEMINOL JS-20 and RS-300 (both manufactured by
Sanyo Chemical Industries, Ltd.) and Aqualon KH-10, Aqualon
KH-1025, Aqualon KH-05, Aqualon HS-10, Aqualon HS-1025, Aqualon
BC-0515, Aqualon BC-10, Aqualon BC-1025, Aqualon BC-20, and Aqualon
BC-2020 (all manufactured by DKS Co. Ltd.).
[0061] The polymerizable nonionic surfactant is not particularly
limited. A specific example thereof is a compound having 1-propenyl
group (--CH.dbd.CH.sub.2CH.sub.3) and a polyoxyethylene group
[--(C.sub.2H.sub.4O).sub.n--H].
[0062] Examples of the polymerizable nonionic surfactant available
on market are, Aqualon RN-20, Aqualon RN-2025, Aqualon RN-30, and
Aqualon RN-50 (all manufactured by DKS Co. Ltd.) and LATEMUL
PD-104, LATEMUL PD-420, LATEMUL PD-430, and LATEMUL PD-450 (all
manufactured by Kao Corporation).
[0063] These surfactants can be used alone or in combination.
[0064] The ratio of the total content of the polymerizable
surfactant to the total content of the compound having the
structure units represented by the Chemical formula 1 and the
Chemical formula 2 is in the range of from 0.001 to 0.1.
[0065] It is preferable to synthesize the copolymer by
copolymerizing the monomers under the presence of a radical
polymerization initiator.
[0066] The radical initiator is not particularly limited. Specific
examples thereof include, but are not limited to, peroxy ketal,
hydroperoxide, dialkyl peroxide, diacylperoxide, peroxydicarbonate,
peroxyester, cyano-based azobisisobutylonitrile,
azobis(2-methylbutylonitrike), azobis(2,2'-isovaleronitrile), and
non-cyano-based dimethyl-2,2' azobis isobutylate. Of these, organic
peroxides and azo-based compounds are preferable and azo compounds
are particularly preferable in terms that they are easy to control
the molecular weight and dissolved at lower temperatures.
[0067] The mass ratio of the radical polymerization initiator to
the monomers is from 0.01 to 0.1.
[0068] To control the molecular weight of the copolymer, a chain
transfer agent is optionally added at the copolymerization of the
monomers.
[0069] The chain transfer agent is not particularly limited.
Specific examples thereof include, but are not limited to, mercapto
acetate, mercapto propionate, 2-propane thiol, 2-meracapto ethanol,
thiophenol, dodecyl mercaptane, 1-dodecane thiol, and
thioglycerol.
[0070] In addition, the reaction temperature is from 50 degrees C.
to 150 degrees C., and preferably from 60 degrees C. to 100 degrees
C.
[0071] The monomer copolmerization time is from 3 hours to 48
hours.
[0072] The pigment is not particularly limited. Inorganic pigments
and organic pigments for black or color are suitable.
[0073] These can be used alone or in combination. These may be used
alone or in combination of two or more thereof.
[0074] Specific examples of the inorganic pigments include, but are
not limited to, titanium oxide, iron oxide, calcium oxide, barium
sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome
yellow, and carbon black.
[0075] It is suitable to use carbon black having a primary particle
diameter of from 15 nm to 40 nm, a specific surface area of from 50
m.sup.2/g to 300 m.sup.2/g according to Brunauer, Emmett, and
Teller (BET) method, a dibutylphthalate (DPB) absorption oil amount
of from 40 ml/100 g to 150 ml/100 g, a volatile content of from 0.5
percent to 10 percent, and pH of from 2 to 9.
[0076] The method of manufacturing carbon black is not particularly
limited. Specific examples thereof include, but are not limited to,
a contact method, a furnace method, a thermal method, a channel
method.
[0077] Specific examples of the organic pigments include, but are
not limited to, azo pigments (azo lakes, insoluble azo pigments,
condensed azo pigments, chelate azo pigments, etc.), polycyclic
pigments (phthalocyanine pigments, perylene pigments, perinone
pigments, anthraquinone pigments, quinacridone pigments, dioxazine
pigments, indigo pigments, thioindigo pigments, isoindolinone
pigments, and quinofuranone pigments, etc.), dye chelates (basic
dye type chelates, acid dye type chelates), nitro pigments, nitroso
pigments, and aniline black can be used.
[0078] Specific examples of the pigments for black color include,
but are not limited to, carbon black (C.I. Pigment Black 7) such as
furnace black, lamp black, acetylene black, and channel black,
metals such as copper and iron (C.I. Pigment Black 11), and metal
oxides such as titanium oxides, and organic pigments such as
aniline black (C.I. Pigment Black 1).
[0079] Specific examples of the pigments for yellow include, but
are not limited to, C.I. Pigment Yellow 1, C.I. Pigment Yellow 2,
C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I. Pigment Yellow
13, C.I. Pigment Yellow 14, C.I. Pigment Yellow 16, C.I. Pigment
Yellow 17, C.I. Pigment Yellow 73, C.I. Pigment Yellow 74, C.I.
Pigment Yellow 75, C.I. Pigment Yellow 83, C.I. Pigment Yellow 93,
C.I. Pigment Yellow 95, C.I. Pigment Yellow 97, C.I. Pigment Yellow
98, C.I. Pigment Yellow 114, C.I. Pigment Yellow 120, C.I. Pigment
Yellow 128, C.I. Pigment Yellow 129, C.I. Pigment Yellow 138, C.I.
Pigment Yellow 150, C.I. Pigment Yellow 151, C.I. Pigment Yellow
154, C.I. Pigment Yellow 155, C.I. Pigment Yellow 174, and C.I.
Pigment Yellow 180.
[0080] Specific examples of pigments for magenta include, but are
not limited to, C.I. Pigment Red 5, C.I. Pigment Red 7, C.I.
Pigment Red 12, C.I. Pigment Red 48 (Ca), C.I. Pigment Red 48 (Mn),
C.I. Pigment Red 57 (Ca), C.I. Pigment Red 57:1, C.I. Pigment Red
112, C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red
146, C.I. Pigment Red 168, C.I. Pigment Red 176, C.I. Pigment Red
184, C.I. Pigment Red 185, C.I. Pigment Red 202, and C.I. Pigment
Violet 19.
[0081] Specific examples of the pigments for cyan include, but are
not limited to, C.I. Pigment Blue 1, C.I. Pigment Blue 2, C.I.
Pigment Blue 3, C.I. Pigment Blue 15, C.I. Pigment Blue 15:3, C.I.
Pigment Blue 15:4, C.I. Pigment Blue 15:34, C.I. Pigment Blue 16,
C.I. Pigment Blue 22, C.I. Pigment Blue 60, C.I. Pigment Blue 63,
C.I. Pigment Blue 66, C.I. Pigment Pat Blue 4, and C.I. Pigment Pat
Blue 60.
[0082] By using C.I. Pigment Yellow 74 as yellow pigment, C.I.
Pigment Red 122 and C.I. Pigment Violet 19 as magenta pigment, and
C.I. Pigment Blue 15:3 as cyan pigment, it is possible to obtain an
ink having an excellent color tone and lightfastness.
[0083] In terms of coloring of images, self-dispersible pigments
are also usable.
[0084] The self-dispersible pigment is preferably anionic.
[0085] The anionic self-dispersion pigment is formed by introducing
an anionic functional group into the surface of a pigment directly
or via another atomic group.
[0086] The anionic functional group means more than a half of
protons are dissociated at pH 7.0.
[0087] The anionic functional group is not particularly limited.
Specific examples thereof include, but are not limited to, a
carboxyl group, a sulfo group, and a phosphonic acid group. Of
these, to improve the optical density of obtained images, a
carboxyl group or a phosphonic acid group is preferable.
[0088] The pigment into which an anionic group is introduced is not
particularly limited. Conventional pigments are suitable.
[0089] The method of introducing the anionic functional group into
the surface of a pigment. For example, oxidation treatment of
carbon black is suitable.
[0090] Carbon black can be oxidized by known methods using
hypochlorite, ozone water, hydrogen peroxide, chlorite, nitric
acid, etc., or other known methods using a diazonium salt, etc.
[0091] Specific examples of commercial products of the pigments
having a surface into which an anioninc group is introduced
include, but are not limited to, CW-1, CW-2, and CW-3 (all
manufactured by Orient Chemical Industries Co., Ltd.), and
CAB-O-JET200, CAB-O-JET300, and CAB-O-JET400 (all manufactured by
Cabot Corporation).
[0092] The content of the pigment in the ink is from 0.5 percent by
mass to 20 percent by mass and preferably from 1 percent by mass to
10 percent by mass.
[0093] In addition, it is preferable to furthermore contain a water
soluble organic solvent. Such a water soluble organic solvent makes
it possible to improve permeability of ink to plain paper and
coated paper and furthermore reduce the occurrence of beading. In
addition, it is also possible to inhibit drying of ink due to
moisturizing effect.
[0094] The water soluble organic solvent is not particularly
limited. Specific examples thereof include, but are not limited to,
polyhydric alcohols such as ethylene glycol, diethylene glycol,
triethylene glycol, tetraethylene glycol, polyethylene glycol,
propylene glycol, dipropylene glycol, tripropylene glycol,
polypropylene glycol, 1,3-butanediol, 3-methyl-1,3-butanediol,
trimethylolethane, trimethylolpropane, 1,5-pentanediol,
1,6-hexanediol, hexylene glycol, glycerin, 1,2,3-butanetriol,
1,2,4-butanetriol, 1,2,6-hexanetriol, isopropylidene glycerol, and
petriol; polyhydric alcohol alkyl ethers such as ethylene glycol
monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol
monomethyl ether, diethylene glycol monoethyl ether, diethylene
glycol monobutyl ether, tetraethylene glycol monomethyl ether, and
propylene glycol monoethyl ether; polyhydric alcohol aryl ethers
such as ethylene glycol monophenyl ether and ethylene glycol
monobenzyl ether; nitrogen-containing heterocyclic compounds such
as 2-pyrrolidone, N-methyl-2-pyrrolidone,
N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone,
.epsilon.-caprolactam, and .gamma.-butyrolactone; amides such as
formamide, N-methylformamide, N,N-dimethylformamide,
3-methoxy-N,N-dimethyl propionamide, and 3-buthoxy-N,N-dimethyl
propionamide; amines such as monoethanolamine, diethanolamine,
triethanolamine, monoethylamine, diethylamine, and triethylamine;
sulfur-containing compounds such as dimethyl sulfoxide, sulfolane,
and thiodiethanol; 3-ethyl-3-hydroxymethyloxetane, propylene
carbonate, and ethylene carbonate. Of these, in terms of prevention
of curling of plain paper, preferred are
3-ethyl-3-hydroxymethyloxetane, isopropylidene glycerol,
N,N-dimethyl-.beta.-methoxy propionamide, and
N,N-dimethyl-.beta.-buthoxy propionamide. Of these, diethylene
glycol, triethylene glycol, 1,3-butanediol,
2,2,4-trimethyl-1,3-pentanediol, and glycerin are excellent to
prevent discharge failure ascribable to evaporation of water.
[0095] The water soluble organic solvent can be used alone or in
combination. These may be used alone or in combination of two or
more thereof.
[0096] Specific examples of the water soluble organic solvents
having good permeation property and relatively low level of
wettability include, but are not limited to, 2-ethyl-1,3-hexanediol
and 2,2,4-trimethyl-1,3-pentanediol.
[0097] Specific examples of the other water soluble organic
solvents include, but are not limited to, aliphatic diols such as
2-ethyl-2-methyl-1,3-propane diol, 2,2-diethyl-1,3-propane diol,
2-methyl-2-propyl-1,3-propane diol, 3,3-dimethyl-1,2-butane diol,
2,4-dimethyl-2,4-pentane diol, 2,5-dimethyl-2,5-hexane diol, and
5-hexene-1,2-diol.
[0098] Specific examples of other water-soluble organic solvents
that can be used in combination with the above-mentioned water
soluble organic solvent include, but are not limited to, alkyl or
aryl ethers of polyhydric alcohols such as diethylene glycol
monobutyl ether, propyleneglycol monobutyl ether, ethylene glycol
monophenyl ether, diethylene glycol monophenyl ether, ethylene
glycol monoallyl ether, and tetraethylene glycol chlorophenyl
ether; and lower alcohols such as ethanol.
[0099] The ink preferably contains a surfactant. Such a surfactant
improves permeability of the ink into plain paper or coated paper
and furthermore reduces the occurrence of beading.
[0100] The surfactant is not particularly limited. Specific
examples thereof include, but are not limited to,
fluorine-containing surfactants, silicone-based surfactants,
anionic surfactants, nonionic surfactants, and ampholytic
surfactants.
[0101] Of these, fluorine-containing surfactants and silicone-based
surfactants are preferable because it can lower the surface tension
of the ink to 30 mN/m or less.
[0102] These surfactants can be used alone or in combination.
[0103] As the fluorine-containing surfactants, for example, a
fluorine-containing nonionic surfactant, a fluorine-containing
anionic surfactant, a fluorine-containing oligomer type
surfactant.
[0104] The number of carbon atoms substituted with fluorine atoms
of a fluorine-containing surfactant is from 2 to 16 and preferably
from 4 to 16.
[0105] Specific examples of the fluorine-containing nonionic
surfactants include, but are not limited to, a perfluoroalkyl
phosphoric acid ester, an adduct of perfluoroalkyl ethylene oxide,
and a polyoxyalkylene ether polymer compound having a
perfluoroalkylether group in its side chain. Of these, the
polyoxyalkylene ether polymer compounds having a
perfluoroalkylether group in its side chain is preferable because
of its low foaming property.
[0106] Specific examples of the fluorine-containing anionic
surfactants include, but are not limited to, a perfluoroalkyl
sulfonic acid compound, a perfluoroalkyl carboxylic acid compound,
a perfluoroalkyl phosphoric acid ester compound, and a
polyoxyalkylene ether polymer compound having a perfluoroalkyl
ether group in its side chain.
[0107] Specific examples of the perfluoroalkyl sulfonic acid
compounds include, but are not limited to, a perfluoroalkyl
sulfonic acid and a salt of perfluoroalkyl sulfonic acid.
[0108] Specific examples of the perfluoroalkyl carboxylic acid
compounds include, but are not limited to, a perfluoroalkyl
carboxylic acid and a salt of perfluoroalkyl carboxylic acid.
[0109] Specific examples of the perfluoroalkyl phosphoric acid
ester compounds include, but are not limited to, a perfluoroalkyl
phosphoric acid ester and a salt of perfluoroalkyl phosphoric acid
esters.
[0110] Specific examples of the polyoxyalkylene ether polymer
compounds having a perfluoroalkyl ether group in its side chain
include, but are not limited to, a polyoxyalkylene ether polymer
having a perfluoroalkyl ether group in its side chain, a sulfuric
acid ester salt of polyoxyalkylene ether polymer having a
perfluoroalkyl ether group in its side chain, and a salt of
polyoxyalkylene ether polymers having a perfluoroalkyl ether group
in its side chain.
[0111] Specific examples of counter ions of fluorine-containing
anionic surfactants include, but are not limited to, Li.sup.+,
Na.sup.+, K.sup.+, NH.sub.4+, .sup.+NH.sub.3(CH.sub.2CH.sub.2OH),
.sup.+NH.sub.2(CH.sub.2CH.sub.2OH).sub.2, and
.sup.+NH(CH.sub.2CH.sub.2OH).sub.3.
[0112] Specific examples of the fluorine-containing surfactants
available on market include, but are not limited to, SURFLON S-111,
SURFLON S-112, SURFLON S-121, SURFLON S-131, SURFLON S-132, SURFLON
S-141, and SURFLON S-145 (all manufactured by ASAHI GLASS CO.,
LTD.); FLUORAD FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C,
FC-430, and FC-431 (all manufactured by SUMITOMO 3M); MEGAFACE
F-470, F-1405, and F-474 (all manufactured by DIC CORPORATION);
ZONYL TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300 UR (all
manufactured by E. I. du Pont de Nemours and Company); Ftergent
FT-110, FT-250, FT-251, FT-400S, FT-150, and FT-400SW (all
manufactured by NEOS COMPANY LIMITED); and POLYFOX PF-136A,
PF-156A, PF-151N, PF-154, and PF-159 (manufactured by OMNOVA
SOLUTIONS INC.).
[0113] The silicone-based surfactants are not particularly limited.
Specific examples thereof include, but are not limited to, side
chain-modified polydimethyl siloxane, both end-modified
polydimethyl siloxane, one end-modified polydimethyl siloxane, and
side chain both end-modified polydimethyl siloxane. Of these, it is
preferable to use a polyether-modified silicone-based surfactant
having a polyoxyethylene group or polyoxyethylene polyoxypropylene
group as the modification group.
[0114] Specific examples of the anionic surfactants include, but
are not limited to, a polyoxyethylene alkylether acetate, a
dodecylbenzene sulfonate, a laurate, and a polyoxyethylene
alkylether sulfate.
[0115] Specific examples of the nonionic surfactants include, but
are not limited to, a polyoxyethylene alkylether, a
polyoxypropylene alkylether, a polyoxyethylene alkylester, a
polyoxy ethylene sorbitan aliphatic ester, a polyoxyethylene
alkylphenylether, a polyoxyethylene alkylamine, and a
polyoxyethylenealkyl amide.
[0116] In addition to the components mentioned above, pH
regulators, preservatives and fungicides, corrosion inhibitors,
anti-oxidants, ultraviolet absorbents, oxygen absorbents, light
stabilizing agents, etc., can be added to the ink.
[0117] The pH regulator is not particularly limited that can adjust
pH to from 8.5 to 11. Specific examples thereof include, but are
not limited to, alcohol amines, hydroxides of alkali metal,
hydroxides of ammonium, hydroxides of phosphonium, and carbonates
of alkali metal.
[0118] Specific examples of the alcohol amines include, but are not
limited to, diethanol amine, triethanol amine, and
2-amino-2-ethyl-1,3-propane diol.
[0119] Specific examples of the hydroxides of alkali metal include,
but are not limited to, lithium hydroxide, sodium hydroxide, and
potassium hydroxide.
[0120] Specific examples of the hydroxides of ammonium include, but
are not limited to, ammonium hydroxide and hydroxides of quaternary
ammonium.
[0121] A specific example of the hydroxides of phosphonium is a
hydroxide of quaternary phosphonium.
[0122] Specific examples of the carbonates of alkali metal include,
but are not limited to, lithium carbonate, sodium carbonate, and
potassium carbonate.
[0123] The preservatives and fungicides are not particularly
limited. Specific examples thereof include, but are not limited,
dehydrosodium acetate, sodium sorbinate, 2-pyridine thiol-1-oxide
sodium, sodium benzoate, and pentachlorophenol sodium.
[0124] The corrosion inhibitors are not particularly limited.
Specific examples thereof include, but are not limited to, acid
sulfite, thiosodium sulfate, ammonium thiodiglycolate, diisopropyl
ammonium nitrite, pentaerythritol tetranitrate, and dicyclohexyl
ammonium nitrite.
[0125] The anti-oxidants are not particularly limited. Specific
examples thereof include, but are not limited to, phenol-based
anti-oxidants (including hindered phenol-based anti-oxidants),
amine-based anti-oxidants, sulfur-based anti-oxidants, and
phosphorus-based anti-oxidants.
[0126] The ultraviolet absorbers are not particularly limited.
Specific examples thereof include, but are not limited to,
benzophenone-based ultraviolet absorbents, benzotriazole-based
ultraviolet absorbents, salicylate-based ultraviolet absorbents,
cyanoacrylate-based ultraviolet absorbents, and nickel complex
salt-based ultraviolet absorbents.
[0127] The ink can be manufactured by dissolving or dispersing a
composition containing a pigment and a copolymer in a solvent
containing water followed by stirring and mixing.
[0128] The copolymer may be used as a pigment dispersion resin
during preparation of a pigment dispersion.
[0129] When dissolving or dispersing a composition in a solvent, it
is possible to use a sand mill, a homogenizer, a ball mill, a paint
shaker, and an ultrasonic dispersion device.
[0130] A stirrer using a stirring blade, a magnetic stirrer, a high
performance disperser etc., can be used to stir or mix a liquid in
which a composition is dissolved or dispersed in a solvent.
[0131] During manufacturing of the ink, it is preferable to filter
coarse particles with a filter, a centrifuge, etc. followed by
degassing.
[0132] The viscosity of the ink at 25 degrees C. is 3 mPas to 20
mPas. When the viscosity of the ink at 25 degrees C. is 3 mPaS or
greater, the image density and text quality are improved. When the
viscosity of the ink at 25 degrees C. is 20 mPaS or less,
dischargeability of the ink is improved.
[0133] The viscosity of the ink at 25 degrees C. can be measured
by, for example, a viscometer (RE-80L, manufactured by TOKI SANGYO
CO., LTD.).
[0134] The surface tension of the ink at 25 degrees C. is 40 mN/m
or less.
[0135] The ink can be contained in a container, which can be used
as an ink cartridge.
[0136] The container is not particularly limited. For example, an
ink bag made of aluminum laminate film, a resin film, etc. is
suitable.
[0137] FIG. 1 is a diagram illustrating an example of the ink
cartridge.
[0138] In an ink cartridge 200, an ink bag 241 is filled with ink
through an ink inlet 242. Subsequent to degassing of the air
remaining in the ink bag 241, the ink inlet 242 is closed by
fusion. The ink bag 241 is disposed in a plastic cartridge housing
244.
[0139] The ink cartridge 200 is detachably attachable to a known
inkjet recording device. The ink is supplied into the inkjet
recording device by inserting the needle of the inkjet recording
device into an outlet 243 made of rubber.
[0140] The ink can be applied to writing materials such as a felt
pen, a ball-point pen, and a plotter pen. This makes it possible to
improve color density on plain paper, in particular white plain
paper.
[0141] Having generally described preferred embodiments of this
invention, further understanding can be obtained by reference to
certain specific examples which are provided herein for the purpose
of illustration only and are not intended to be limiting. In the
descriptions in the following examples, the numbers represent
weight ratios in parts, unless otherwise specified.
EXAMPLES
[0142] The present disclosure is described with reference to
Examples but not limited thereto.
Synthesis of Compound Represented by Chemical Formula 4-1
[0143] 62.0 g (525 mmol) of 1,6-hexanediol (manufactured by Tokyo
Chemical Industry Co., Ltd.) was dissolved in 700 mL of methylene
chloride (dichloromethane) and 20.7 g (262 mmol) of pyridine was
further added. To this solution, a solution in which 50.0 g (262
mmol) of 2-naphthalene carbonyl chloride (manufacture by Tokyo
Chemical Industry Co., Ltd.) was dissolved in 100 ml of
dichloromethane was dripped in two hours followed by stirring at
room temperature for six hours. Subsequent to rinsing with water,
an organic phase was isolated. Next, after drying the organic phase
with magnesium sulfide, the solvent was removed. The resultant was
furthermore refined by silica gel column chromatography with a
solvent mixture of a dichloromethane and methanol with a volume
ratio of 98:2 serving as an eluent to obtain 52.5 g of 2-naphthoic
acid-2-hydroxyethyl ester.
[0144] Next, 42.1 g (155 mmol) of 2-naphthoic acid-2-hydroxyethyl
ester was dissolved in 80 mL of dried methylethylketone followed by
heating to 60 degrees C. To this solution, a solution in which 24.0
g (155 mmol) of 2-methacryloyloxy ethylisocyanate (Karenz MOI,
manufactured by SHOWA DENKO K.K.) was dissolved in 20 mL of dried
methylketone was dripped in one hour while being stirred followed
by stirring at 70 degrees C. for 12 hours. Subsequent to cooling
down to room temperature, the solvent was distilled away. The
resultant was refined by silica gel column chromatography with a
solvent mixture of a methylene chloride and methanol with a volume
ratio of 99:1 serving as an eluent to obtain 57.0 g of the compound
represented by the Chemical formula 4-1.
##STR00014##
[0145] FIG. 2 is a graph illustrating an IR spectrum of the
compound represented by the Chemical formula 4-1.
Synthesis of Compound Represented by Chemical Formula 4-2
[0146] A compound represented by the Chemical formula 4-2 was
obtained in the same manner as the compound represented by the
Chemical formula 4-1 except that 525 mmol of ethylene glycol
(manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) was used
instead of 525 mmol of 1,6-hexanediol.
##STR00015##
Synthesis of Compound Represented by Chemical Formula 4-3
[0147] The compound represented by the Chemical formula 4-3 was
obtained in the same manner as the compound represented by the
Chemical formula 4-1 except that 525 mmol of 1,12-dodecane diol
(manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) was used
instead of 525 mmol of 1,6-hexanediol.
##STR00016##
Synthesis of Compound Represented by Chemical Formula 4-4
[0148] The compound represented by the Chemical formula 4-4 was
obtained in the same manner as the compound represented by the
Chemical formula 4-1 except that 525 mmol of 1,16-hexadecane diol
(manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) was used
instead of 525 mmol of 1,6-hexanediol.
##STR00017##
Synthesis of Copolymer 1-1
[0149] 2.22 g (purity: 89.2 percent, 9.42 mmol) of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.) and 4.02 g (9.40 mmol) of
the compound represented by the Chemical formula 4-1 were dissolved
in 30 g of dried 1-methoxy-2-propanol to obtain a monomer solution.
Next, all the amount of the monomer solution was divided into 10
percent by mass of the solution and 90 percent by mass of the
solution. The 10 percent by mass solution was heated to 90 degrees
C. in an argon atmosphere to obtain a solution A, which was charged
in a flask. 0.240 g (1.46 mmol) of 2,2'-azoisobutylonitrile
(manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved
in the 90 percent by mass to obtain a solution B. The solution B
was dripped to the solution A in the flask in 1.5 hours to
synthesize a copolymer while being stirred. Furthermore, subsequent
to four-hour stirring at 75 degrees C., the resultant was cooled
down to room temperature. Next, the resultant was put in hexane
followed by filtration.
[0150] In addition, the filtered matter was dissolved in
tetrahydrofuran followed by drying with a reduced pressure to
obtain 6.12 g of a precursor of the copolymer 1-1.
[0151] FIG. 3 is a graph illustrating an IR spectrum of the
precursor of the copolymer 1-1.
[0152] 5.00 g of the obtained precursor of the copolymer 1-1 was
dissolved in an aqueous solution of tetraethyl ammonium hydroxide
in such a manner that the concentration of the copolymer 1-1 was 10
percent by mass and the pH thereof was 8.0 to prepare a 10 percent
by mass aqueous solution of the copolymer 1-1. The 10 percent by
mass aqueous solution of the copolymer 1-1 had a viscosity of 2.0
mPas.
[0153] Viscosity of 10 Percent by Mass Aqueous Solution of
Copolymer
[0154] The viscosity of 10% by mass aqueous solution of the
copolymers was measured at 25 degrees C. by using a viscometer
(TV-22 type, Cone plate type, manufactured by TOKI SANGYO CO.,
LTD.). To be specific, 1.1 mL of the 10 percent by mass aqueous
solution of copolymer was placed in the sample cup of the
viscometer. The cup was mounted onto the viscometer and thereafter
left still for one minute. Thereafter, the viscosity value was read
one minute after the rotor of the viscometer was rotated.
Synthesis of Copolymer 1-2
[0155] 10 percent by mass aqueous solution of the copolymer 1-2 was
obtained in the same manner as the copolymer 1-1 except that 9.40
mmol of the compound represented by the Chemical formula 4-2 was
used instead of 9.40 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 1-2 had a viscosity of 1.8 mPas.
Synthesis of Copolymer 1-3
[0156] 10 percent by mass aqueous solution of the copolymer 1-3 was
obtained in the same manner as the copolymer 1-1 except that 9.40
mmol of the compound represented by the Chemical formula 4-3 was
used instead of 9.40 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 1-3 had a viscosity of 1.7 mPas.
Synthesis of Copolymer 1-4
[0157] 10 percent by mass aqueous solution of the copolymer 1-4 was
obtained in the same manner as the copolymer 1-1 except that 9.40
mmol of the compound represented by the Chemical formula 4-4 was
used instead of 9.40 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 1-4 had a viscosity of 2.1 mPas.
Synthesis of Copolymer 1-5
[0158] 10 percent by mass aqueous solution of the copolymer 1-5 was
obtained in the same manner as the copolymer 1-1 except that 9.42
mmol of LIGHT ACRYLATE P-1A (manufactured by Kyoeisha Chemical Co.,
Ltd.) was used instead of 9.42 mmol of Phosmer.TM. M (manufactured
by Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution
of the copolymer 1-5 had a viscosity of 1.9 mPas.
Synthesis of Copolymer 1-6
[0159] 10 percent by mass aqueous solution of the copolymer 1-6 was
obtained in the same manner as the copolymer 1-1 except that 9.42
mmol of Phosmer.TM. PE (manufactured by Uni-Chemical Co., Ltd.) was
used instead of 9.42 mmol of Phosmer.TM. M (manufactured by
Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution of
the copolymer 1-6 had a viscosity of 2.0 mPas.
Synthesis of Copolymer 1-7
[0160] 10 percent by mass aqueous solution of the copolymer 1-7 was
obtained in the same manner as the copolymer 1-1 except that 9.42
mmol of Phosmer.TM. PP (manufactured by Uni-Chemical Co., Ltd.) was
used instead of 9.42 mmol of Phosmer.TM. M (manufactured by
Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution of
the copolymer 1-7 had a viscosity of 1.8 mPas.
Synthesis of Copolymer 1-8
[0161] 10 percent by mass aqueous solution of the copolymer 1-8 was
obtained in the same manner as the copolymer 1-1 except that 9.42
mmol of acid phophoxypoly(oxyethylene oxypropylene)glycol
methacrylate was used instead of 9.42 mmol of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.). The 10 percent by mass
aqueous solution of the copolymer 1-8 had a viscosity of 2.2
mPas.
Synthesis of Copolymer 1-9
[0162] 10 percent by mass aqueous solution of the copolymer 1-9 was
obtained in the same manner as the copolymer 1-1 except that the
amount of Phosmer.TM. M (manufactured by Uni-Chemical Co., Ltd.)
was changed to 4.71 mmol. The 10 percent by mass aqueous solution
of the copolymer 1-9 had a viscosity of 2.6 mPas.
Synthesis of Copolymer 1-10
[0163] 10 percent by mass aqueous solution of the copolymer 1-10
was obtained in the same manner as the copolymer 1-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) was changed to 28.26 mmol. The 10 percent by mass aqueous
solution of the copolymer 1-10 had a viscosity of 1.6 mPas.
[0164] FIG. 4 is a graph illustrating an IR spectrum of the
precursor of the copolymer 1-10.
Synthesis of Copolymer 1-11
[0165] 10 percent by mass aqueous solution of the copolymer 1-11
was obtained in the same manner as the copolymer 1-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) was changed to 37.68 mmol. The 10 percent by mass aqueous
solution of the copolymer 1-11 had a viscosity of 1.5 mPas.
Synthesis of Copolymer 1-12
[0166] 10 percent by mass aqueous solution of the copolymer 1-12
was obtained in the same manner as the copolymer 1-1 except that an
aqueous solution of sodium hydroxide was used instead of the
aqueous solution of tetraethyl ammonium hydroxide. The 10 percent
by mass aqueous solution of the copolymer 1-12 had a viscosity of
1.4 mPas.
Synthesis of Copolymer 1-13
[0167] 10 percent by mass aqueous solution of the copolymer 1-13
was obtained in the same manner as the copolymer 1-1 except that
94.2 mmol of LIGHT ACRYLATE P-1A (manufactured by Kyoeisha Chemical
Co., Ltd.) and an aqueous solution of sodium hydroxide were
respectively used instead of 9.42 mmol of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.) and an aqueous solution of
tetraethyl ammonium hydroxide. The 10 percent by mass aqueous
solution of the copolymer 1-13 had a viscosity of 17.8 mPas.
Synthesis of Copolymer 1-14
[0168] 59.8 g (140 mmol) of the compound represented by the
Chemical formula 4-1 was dissolved in 6.60 g (purity 89.2 percent,
28.0 mmol) of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.). Next, 100 g of deionized water, 3.0 g of radical
polimerizable anionic surfactant (Aqualon KH-10, manufactured by
DKS Co. Ltd.), and 1.0 g of ammonium persulfate were added to the
solution followed by dispersion by a HOMO MIXER to obtain a
pre-emulsion. Thereafter, 2.0 g of Aqualon KH-10 (manufactured by
DKS Co. Ltd.) was added to 100 g of deionized water, which was
thereafter heated to 80 degrees C. in argon atmosphere. Thereafter,
10 percent by mass of the pre-emulsion was added to conduct
polymerization for 30 minutes. Next, 90 percent by mass of the
pre-emulsion was dripped to the resultant in two hours while being
stirred followed by polymerization for two hours at 80 degrees C.
Subsequent to cooling down to room temperature, the resultant was
distilled away. Next, the filtered matter was neutralized with an
aqueous solution of tetraethyl ammonium hydroxide to obtain 30
percent by mass aqueous solution of the copolymer 1-14. The 30
percent by mass aqueous solution of the copolymer 1-14 was diluted
with water. The 10 percent by mass aqueous solution of the
copolymer 1-14 had a viscosity of 28.5 mPas.
Synthesis of Copolymer 1-15
[0169] 64.1 g (150 mmol) of the compound represented by the
Chemical formula 4-1 was dissolved in 11.76 g (60.0 mmol) of LIGHT
ACRYLATE P-1A (manufactured by Kyoeisha Chemical Co., Ltd.). Next,
130 g of deionized water, 4.0 g of radical poi imerizable anionic
surfactant (Aqualon KH-10, manufactured by DKS Co. Ltd.), and 1.3 g
of ammonium persulfate were added to the solution followed by
dispersion by a HOMO MIXER to obtain a pre-emulsion. 30 percent by
mass aqueous solution of Copolymer 1-15 was obtained in the same
manner as the copolymer 1-14 except that the thus-obtained
pre-emulsion was used. The 30 percent by mass aqueous solution of
the copolymer 1-15 was diluted with water. The 10 percent by mass
aqueous solution of the copolymer 1-15 had a viscosity of 29.4
mPas.
[0170] In Table 1, the ingredients of the copolymers 1-1 to 1-15
are shown.
TABLE-US-00001 TABLE 1 Molar ratio Copoly- Chemical Chemical
Chemical Chemical mer 1 formula 1 formula 2 formula 3 formula 4
M.sub.1.sup.+ M.sub.2.sup.+ 1-1 1 1 Chemical Chemical TEA formula
3-1 formula 4-1 1-2 1 1 Chemical Chemical TEA formula 3-1 formula
4-2 1-3 1 1 Chemical Chemical TEA formula 3-1 formula 4-3 1-4 1 1
Chemical Chemical TEA formula 3-1 formula 4-4 1-5 1 1 Chemical
Chemical TEA formula 3-2 formula 4-1 1-6 1 1 Chemical Chemical TEA
formula 3-3 formula 4-1 1-7 1 1 Chemical Chemical TEA formula 3-4
formula 4-1 1-8 1 1 Chemical Chemical TEA formula 3-5 formula 4-1
1-9 0.5 1 Chemical Chemical TEA formula 3-1 formula 4-1 1-10 3 1
Chemical Chemical TEA formula 3-1 formula 4-1 1-11 4 1 Chemical
Chemical TEA formula 3-1 formula 4-1 1-12 1 1 Chemical Chemical
Na.sup.+ formula 3-1 formula 4-1 1-13 10 1 Chemical Chemical
Na.sup.+ formula 3-2 formula 4-4 1-14 0.2 1 Chemical Chemical TEA
formula 3-1 formula 4-1 1-15 0.4 1 Chemical Chemical TEA formula
3-2 formula 4-1
[0171] TEA represents tetraethylammonium ion.
Preparation of Pigment Dispersion 1-1
[0172] 16.0 parts of carbon black (NIPEX 150, manufactured by
Degussa AG) and 44.0 parts of deionized water were added to 40.0
parts of the 10 percent by mass aqueous solution of the copolymer
1-1 followed by stirring for 12 hours. Next, using a disk type bead
mill (KDL type, manufactured by Shinmaru Enterprises Corporation),
the resultant was subject to circulation dispersion at a peripheral
speed of 10 m/s for one hour. The used media were zirconia balls
having a diameter of 0.1 mm. Furthermore, subsequent to filtration
by a membrane filter having an opening diameter of 1.2 .mu.m,
deionized water was added in such a manner that the concentration
of the pigment was 16 percent by mass to obtain a pigment
dispersion 1-1.
Preparation of Pigment Dispersions 1-2 to 1-13
[0173] Pigment dispersions 1-2 to 1-13 were obtained in the same
manner as in the pigment dispersion 1-1 except that each of 10
percent by mass aqueous solutions of the copolymers 1-2 to 1-13 was
used instead of 10 percent by mass aqueous solution the copolymer
1-1.
Preparation of Pigment Dispersion 1-14
[0174] The pigment dispersion 1-14 was obtained in the same manner
as the pigment dispersion 1-1 except that 20.0 parts of cyan
pigment (CHROMOFINR BLUE, Pigment blue 15:3, manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and 40.0 parts
of deionized water were used instead of 16.0 parts of carbon black
(NIPEX 1500, manufactured by Degussa AG) and 44.0 parts of
deionized water) and the concentration of the pigment was 20
percent by mass.
Preparation of Pigment Dispersion 1-15
[0175] The pigment dispersion 1-15 was obtained in the same manner
as the pigment dispersion 1-1 except that 20.0 parts of magenta
pigment (TONER MAGENTA E0002, Pigment red 122, manufactured by
Clariant K.K.) was used instead of 16.0 parts of carbon black
(NIPEX 1500, manufactured by Degussa AG) and 44.0 parts of
deionized water) and the concentration of the pigment was 20
percent by mass.
Preparation of Pigment Dispersion 1-16
[0176] The pigment dispersion 1-16 was obtained in the same manner
as the pigment dispersion 1-1 except that 20.0 parts of yellow
pigment (FAST YELLOW, Pigment yellow 531, manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used
instead of 16.0 parts of carbon black (NIPEX 1500, manufactured by
Degussa AG) and 44.0 parts of deionized water) and the
concentration of the pigment was 20 percent by mass.
Preparation of Pigment Dispersion 1-17
[0177] 50 g of dried carbon black, 100 mL of deionized water, and
15.5 g (50 mmol) of the compound represented by the following
Chemical formula I were mixed. The mixture was heated to 60 degrees
C. while being stirred at 300 rpm.
##STR00018##
[0178] Thereafter, 50 mmol of 20 percent aqueous solution of sodium
nitrite was added in 15 minutes. Thereafter, the resultant was
stirred at 60 degrees C. for three hours. Furthermore, subsequent
to dilution with 75 mL of deionized water, the resultant was
filtrated. Furthermore, deionized water was added in such a manner
that the concentration of the pigment was 20 percent by mass to
obtain a pigment dispersion 1-17 having a treated surface.
Preparation of Pigment Dispersion 1-18
[0179] Thereafter, 4.50 g of p-amino benzoate was added to 150 g of
deionized water heated to 60 degrees C. followed by mixing at 8,000
rpm for 10 minutes.
[0180] Next, after a solution in which 1.8 g of sodium nitrite was
dissolved in 15.0 g of deionized water and 20.0 g of copper
phthalocyanine pigment (Pigment Blue 15:4, manufactured by Sun
Chemical Corporation) were sequentially added to the mixture
followed by mixing at 8,500 rpm for one hour. Furthermore, a
solution in which 4.5 g of p-amino benzoic acid was dissolved in
15.0 g of deionized water was added to the mixture followed by
mixing at 65 degrees C. at 8,500 rpm for three hours. The
thus-obtained mixture was filtered by a mesh of 200 nm. Subsequent
to rinsing with water, the resultant was dispersed in water. Coarse
particles were removed by centrifugal and deionized water was added
in such a manner that the concentration of the pigment was 20.0
percent by mass to obtain a pigment dispersion 1-18 having a
surface treated with p-amino benzoic acid.
Preparation of Pigment Dispersion 1-19
[0181] The pigment dispersion 1-19 having a surface treated with
sulfanilic acid was obtained in the same manner as the pigment
dispersion 1-18 except that sulfanilic acid and a magenta pigment
(Pigment red 122, manufactured by Sun Chemical) were used instead
of p-amino benzoic acid and copper phthalocyanine pigment (Pigment
blue 15:4, manufactured by Sun Chemical).
[0182] The ingredients of the pigment dispersions are shown in
Table 2.
TABLE-US-00002 TABLE 2 Pigment dispersion 1 Copolymer 1 Pigment
Storage stability 1-1 1-1 Black A 1-2 1-2 Black A 1-3 1-3 Black B
1-4 1-4 Black B 1-5 1-5 Black A 1-6 1-6 Black A 1-7 1-7 Black A 1-8
1-8 Black A 1-9 1-9 Black A 1-10 1-10 Black A 1-11 1-11 Black B
1-12 1-12 Black B 1-13 1-13 Black B 1-14 1-1 Cyan A 1-15 1-1
Magenta A 1-16 1-1 Yellow A 1-17 -- Black -- 1-18 -- Cyan -- 1-19
-- Magenta --
[0183] Storage stability of the pigment dispersions was
evaluated.
[0184] Storage Stability of Pigment Dispersion
[0185] A glass container was filled with the pigment dispersion and
stored at 70 degrees C. for two weeks. The viscosity change rate
was obtained from the following relation:
|(Viscosity of pigment dispersion after storage)-(Viscosity of
pigment dispersion before storage)|/(Viscosity of pigment
dispersion before storage).times.100, to evaluate the storage
stability. The viscosity of the pigment dispersion at 25 degrees C.
was measured at 50 rpm by using a viscometer (RE80L, manufactured
by TOKI SANGYO CO., LTD.). The change rate of the viscosity was
rated as follows: A: Less than 5% B 5% to less than 8% C: 8% to
less than 10% D: 10% to less than 30% E: 30% or greater
[0186] As seen in Table 2, it is confirmed that the pigment
dispersions 1-1 to 1-16 have excellent storage stability.
Example 1-1
[0187] 45.0 parts of pigment dispersion 1-1, 10.0 parts of
1,3-butanediol, 10.0 parts of glycerin, 10.0 parts of
3-methoxy-N,N-diemthyl propionamide, 1.0 part of
fluorine-containing surfactant (ZONYL.TM. FS-300, solid portion: 40
percent by mass, manufactured by E. I. du Pont de Nemours and
Company), and 24.0 parts of deionized water were mixed followed by
stirring for one hour and filtration by a membrane filter having an
opening diameter of 1.2 micro meter to obtain an ink.
Examples 1-2 to 1-13
[0188] Inks were obtained in the same manner as in Example 1-1
except that each of the pigment dispersions 1-2 to 1-13 was used
instead of the pigment dispersion 1-1.
Example 1-14
[0189] Ink was obtained in the same manner as in Example 1-1 except
that 30.0 parts of the pigment dispersion 1-14 was used instead of
45.0 parts of the pigment dispersion 1-1 and the contents of
1,3-butanediol and 3-methoxy-N,N-dimethyl propionamide were
respectively changed to 15.0 parts and 20.0 parts.
Example 1-15
[0190] Ink was obtained in the same manner as in Example 1-1 except
that 30.0 parts of the pigment dispersion 1-15 was used instead of
45.0 parts of the pigment dispersion 1-1 and the contents of
deionized water was changed to 9.0 parts.
Example 1-16
[0191] Ink was obtained in the same manner as in Example 1-15
except that the pigment dispersion 1-16 was used instead of the
pigment dispersion 1-15.
Preparation of Medium Dispersion A
[0192] 2.0 parts of 2-ethyl-1,3-hexanediol, 10.0 parts of glycerol,
15.0 parts of 3-methoxy-N,N-dimethyl propaneamide, 15.0 parts of
3-buthoxy-N,N-dimethyl propaneamide, 0.05 parts of
2-(cyclohexylamino)ethane sulfonic acid, 0.5 parts of
2,4,7,9-tetramethyl-4,7-decane diol, 0.25 parts of ZONYL FS-300
(manufactured by E. I. du Pont de Nemours and Company), 0.01 parts
of diethanolamine, and 12.93 parts of deionized water were mixed
followed by stirring for 30 minutes to obtain a medium dispersion
A.
Example 1-17
[0193] 37.5 parts of the pigment dispersion 1-17 was added to the
medium dispersion A followed by stirring for 30 minutes.
Thereafter, 6.67 parts of 30 percent by mass aqueous solution of
the copolymer 1-14 was added followed by stirring for 30 minutes.
Furthermore, ink was obtained by filtering the resultant with a
membrane filter having an opening diameter of 1.2 .mu.m.
Preparation of Medium Dispersion B
[0194] The medium dispersion B was obtained in the same manner as
the medium dispersion A except that the contents of
3-methoxy-N,N-dimetheyl propaneamide, 3-buthoxy-N,N-dimetheyl
propaneamide, and deionized water were respectively changed to 20.0
parts, 20.0 parts, and 17.93 parts.
Example 1-18
[0195] 22.5 parts of the pigment dispersion 1-18 was added to the
medium dispersion B followed by stirring for 30 minutes.
Thereafter, 6.67 parts of 30 percent by mass aqueous solution of
the copolymer 1-15 was added followed by stirring for 30 minutes.
Furthermore, ink was obtained by filtering the resultant with a
membrane filter having an opening diameter of 1.2 .mu.m.
Example 1-19
[0196] Ink was obtained in the same manner as in Example 1-17
except that the pigment dispersion 1-19 and 30 percent by mass
aqueous solution of the copolymer 1-15 were used instead of the
pigment dispersion 1-17 and 30 percent by mass aqueous solution of
the copolymer 1-14.
Example 1-20
[0197] Ink was obtained in the same manner as in Example 1-18
except that the pigment dispersion 1-14 was used instead of the
pigment dispersion 1-18.
[0198] The ingredients of Examples 1-1 to 1-20 are shown in Table
3.
TABLE-US-00003 TABLE 3 Example 1 Pigment Dispersion 1 Copolymer 1
1-1 1-1 -- 1-2 1-2 -- 1-3 1-3 -- 1-4 1-4 -- 1-5 1-5 -- 1-6 1-6 --
1-7 1-7 -- 1-8 1-8 -- 1-9 1-9 -- 1-10 1-10 -- 1-11 1-11 -- 1-12
1-12 -- 1-13 1-13 -- 1-14 1-14 -- 1-15 1-15 -- 1-16 1-16 -- 1-17
1-17 1-14 1-18 1-18 1-15 1-19 1-19 1-15 1-20 1-14 1-15
Synthesis of Copolymer 2-1
[0199] 2.01 g (purity: 89.2 percent, 8.51 mmol) of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.), 0.58 g (3.40 mmol) of
diacetone acrylamide (manufactured by TOKYO CHEMICAL INDUSTRY CO.,
LTD.), and 3.64 g (8.51 mmol) of the compound represented by the
Chemical formula 4-1 were dissolved in 30 g of dried
1-methoxy-2-propanol to obtain a monomer solution. Next, all the
amount of the monomer solution was divided into 10 percent by mass
of the solution and 90 percent by mass of the solution. The 10
percent by mass solution was heated to 90 degrees C. in an argon
atmosphere to obtain a solution A, which was charged in a flask.
0.240 g (1.46 mmol) of 2,2'-azoisobutylonitrile (manufactured by
Tokyo Chemical Industry Co., Ltd.) was dissolved in the 90 percent
by mass to obtain a solution B. The solution B was dripped to the
solution A in the flask in 1.5 hours to synthesize a copolymer
while being stirred. Furthermore, subsequent to four-hour stirring
at 75 degrees C., the resultant was cooled down to room
temperature. Next, the resultant was put in hexane followed by
filtration.
[0200] In addition, the filtered matter was dissolved in
tetrahydrofuran followed by drying with a reduced pressure to
obtain 6.10 g of a precursor of the copolymer 2-1.
[0201] FIG. 5 is a graph illustrating an IR spectrum of the
precursor of the copolymer 2-1.
[0202] 5.00 g of the obtained precursor of the copolymer 2-1 was
dissolved in an aqueous solution of tetraethyl ammonium hydroxide
in such a manner that the concentration of the copolymer 2-1 was 10
percent by mass and the pH thereof was 8.0 to prepare a 10 percent
by mass aqueous solution of the copolymer 2-1. The 10 percent by
mass aqueous solution of the copolymer 2-1 had a viscosity of 2.2
mPas.
Synthesis of Copolymer 2-2
[0203] 10 percent by mass aqueous solution of the copolymer 2-2 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of the compound represented by the Chemical formula 4-2 was
used instead of 8.51 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 2-2 had a viscosity of 1.9 mPas.
Synthesis of Copolymer 2-3
[0204] 10 percent by mass aqueous solution of the copolymer 2-3 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of the compound represented by the Chemical formula 4-3 was
used instead of 8.51 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 2-3 had a viscosity of 2.1 mPas.
Synthesis of Copolymer 2-4
[0205] 10 percent by mass aqueous solution of the copolymer 2-4 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of the compound represented by the Chemical formula 4-4 was
used instead of 8.51 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 2-4 had a viscosity of 2.0 mPas.
Synthesis of Copolymer 2-5
[0206] 10 percent by mass aqueous solution of the copolymer 2-5 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of LIGHT ACRYLATE P-1A (manufactured by Kyoeisha Chemical Co.,
Ltd.) was used instead of 8.51 mmol of Phosmer.TM. M (manufactured
by Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution
of the copolymer 2-5 had a viscosity of 1.9 mPas.
Synthesis of Copolymer 2-6
[0207] 10 percent by mass aqueous solution of the copolymer 2-6 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of Phosmer.TM. PE (manufactured by Uni-Chemical Co., Ltd.) was
used instead of 8.51 mmol of Phosmer.TM. M (manufactured by
Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution of
the copolymer 2-6 had a viscosity of 2.1 mPas.
Synthesis of Copolymer 2-7
[0208] 10 percent by mass aqueous solution of the copolymer 2-7 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of Phosmer.TM. PP (manufactured by Uni-Chemical Co., Ltd.) was
used instead of 8.51 mmol of Phosmer.TM. M (manufactured by
Uni-Chemical Co., Ltd.). The 10 percent by mass aqueous solution of
the copolymer 2-7 had a viscosity of 1.6 mPas.
Synthesis of Copolymer 2-8
[0209] 10 percent by mass aqueous solution of the copolymer 2-8 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of acid phophoxypoly(oxyethylene oxypropylene)glycol
methacrylate was used instead of 8.51 mmol of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.). The 10 percent by mass
aqueous solution of the copolymer 2-8 had a viscosity of 2.4
mPas.
Synthesis of Copolymer 2-9
[0210] 10 percent by mass aqueous solution of the copolymer 2-9 was
obtained in the same manner as the copolymer 2-1 except that 3.40
mmol of diacetone methacrylamide (manufactured by TOKYO CHEMICAL
INDUSTRY CO., LTD.) was used instead of 3.40 mmol of diacetone
acrylamide (manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) The
10 percent by mass aqueous solution of the copolymer 2-9 had a
viscosity of 2.1 mPas.
Synthesis of Copolymer 2-10
[0211] 10 percent by mass aqueous solution of the copolymer 2-10
was obtained in the same manner as the copolymer 2-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) was changed to 5.11 mmol. The 10 percent by mass aqueous
solution of the copolymer 2-10 had a viscosity of 1.7 mPas.
[0212] FIG. 6 is a graph illustrating an IR spectrum of the
precursor of the copolymer 2-10.
Synthesis of Copolymer 2-11
[0213] 10 percent by mass aqueous solution of the copolymer 2-11
was obtained in the same manner as the copolymer 2-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) and the amount of diacetone acrylamide (manufactured by TOKYO
CHEMICAL INDUSTRY CO., LTD.) were respectively changed to 51.1 mmol
and 34.0 mmol. The 10 percent by mass aqueous solution of the
copolymer 2-11 had a viscosity of 1.4 mPas.
Synthesis of Copolymer 2-12
[0214] 10 percent by mass aqueous solution of the copolymer 2-12
was obtained in the same manner as the copolymer 2-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) and the amount of diacetone acrylamide (manufactured by TOKYO
CHEMICAL INDUSTRY CO., LTD.) were respectively changed to 2.55 mmol
and 0.85 mmol. The 10 percent by mass aqueous solution of the
copolymer 2-12 had a viscosity of 1.6 mPas.
Synthesis of Copolymer 2-13
[0215] 10 percent by mass aqueous solution of the copolymer 2-13
was obtained in the same manner as the copolymer 2-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) and the amount of diacetone acrylamide (manufactured by TOKYO
CHEMICAL INDUSTRY CO., LTD.) were respectively changed to 68.1 mmol
and 51.0 mmol. The 10 percent by mass aqueous solution of the
copolymer 2-13 had a viscosity of 2.5 mPas.
Synthesis of Copolymer 2-14
[0216] 10 percent by mass aqueous solution of the copolymer 2-14
was obtained in the same manner as the copolymer 2-1 except that
the amount of Phosmer.TM. M (manufactured by Uni-Chemical Co.,
Ltd.) and the amount of diacetone acrylamide (manufactured by TOKYO
CHEMICAL INDUSTRY CO., LTD.) were respectively changed to 76.6 mmol
and 0.85 mmol. The 10 percent by mass aqueous solution of the
copolymer 2-14 had a viscosity of 1.9 mPas.
Synthesis of Copolymer 2-15
[0217] 10 percent by mass aqueous solution of the copolymer 2-15
was obtained in the same manner as the copolymer 2-1 except that an
aqueous solution of sodium hydroxide was used instead of the
aqueous solution of tetraethyl ammonium hydroxide. The 10 percent
by mass aqueous solution of the copolymer 2-15 had a viscosity of
1.5 mPas.
Synthesis of Copolymer 2-16
[0218] 10 percent by mass aqueous solution of the copolymer 2-16
was obtained in the same manner as the copolymer 2-1 except that
8.51 mmol of LIGHT ACRYLATE P-1A (manufactured by Kyoeisha Chemical
Co., Ltd.) and an aqueous solution of sodium hydroxide were used
instead of 8.51 mmol of Phosmer.TM. M (manufactured by Uni-Chemical
Co., Ltd.) and the aqueous solution of tetraethyl ammonium
hydroxide. The 10 percent by mass aqueous solution of the copolymer
2-16 had a viscosity of 19.9 mPas.
Synthesis of Copolymer 2-17
[0219] 55.3 g (129.5 mmol) of the compound represented by the
Chemical formula 4-1 and 2.19 g (12.9 mmol) of diacetone acrylamide
(manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) were dissolved
in 9.15 g (purity 89.2 percent, 38.8 mmol) of Phosmer.TM. M
(manufactured by Uni-Chemical Co., Ltd.). Next, 100 g of deionized
water, 3.0 g of radical polimerizable anionic surfactant (Aqualon
KH-10, manufactured by DKS Co. Ltd.), and 1.0 g of ammonium
persulfate were added to the solution followed by dispersion by a
HOMO MIXER to obtain a pre-emulsion. 30 percent by mass aqueous
solution of Copolymer 2-17 was obtained in the same manner as the
copolymer 1-14 except that the thus-obtained pre-emulsion was used.
The 30 percent by mass aqueous solution of the copolymer 2-17 was
diluted with water. The 10 percent by mass aqueous solution of the
copolymer 2-17 had a viscosity of 28.8 mPas.
Synthesis of Copolymer 2-18
[0220] 55.8 g (130.5 mmol) of the compound represented by the
Chemical formula 4-1 and 2.21 g (13.1 mmol) of diacetone acrylamide
(manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.) were dissolved
in 7.68 g (39.2 mmol) of LIGHT ACRYLATE P-1A (manufactured by
Kyoeisha Chemical Co., Ltd.). Next, 100 g of deionized water, 4.0 g
of radical polimerizable anionic surfactant (Aqualon KH-10,
manufactured by DKS Co. Ltd.), and 1.3 g of ammonium persulfate
were added to the solution followed by dispersion by a HOMO MIXER
to obtain a pre-emulsion. 30 percent by mass aqueous solution of
Copolymer 2-18 was obtained in the same manner as the copolymer
1-14 except that the thus-obtained pre-emulsion was used. The 30
percent by mass aqueous solution of the copolymer 2-18 was diluted
with water. The 10 percent by mass aqueous solution of the
copolymer 2-18 had a viscosity of 27.5 mPas.
[0221] In Table 4, the ingredients of the copolymers 2-1 to 2-18
are shown.
TABLE-US-00004 TABLE 4 Molar ratio Chemical Chemical Chemical
Chemical Chemical Chemical Copolymer 2 formula 1 formula 2 formula
5 formula 3 formula 4 formula 6 M.sub.1.sup.+ M.sub.2.sup.+ 2-1 1 1
0.4 3-1 4-1 DAAM TEA 2-2 1 1 0.4 3-1 4-2 DAAM TEA 2-3 1 1 0.4 3-1
4-3 DAAM TEA 2-4 1 1 0.4 3-1 4-4 DAAM TEA 2-5 1 1 0.4 3-2 4-1 DAAM
TEA 2-6 1 1 0.4 3-3 4-1 DAAM TEA 2-7 1 1 0.4 3-4 4-1 DAAM TEA 2-8 1
1 0.4 3-5 4-1 DAAM TEA 2-9 1 1 0.4 3-1 4-1 DMAAM TEA 2-10 0.6 1 0.4
3-1 4-1 DAAM TEA 2-11 6 1 4 3-1 4-1 DAAM TEA 2-12 0.3 1 0.1 3-1 4-1
DAAM TEA 2-13 8 1 6 3-1 4-4 DAAM TEA 2-14 9 1 0.1 3-1 4-1 DAAM TEA
2-15 1 1 0.4 3-1 4-1 DAAM Na.sup.+ 2-16 1 1 0.4 3-2 4-4 DAAM
Na.sup.+ 2-17 0.3 1 0.1 3-1 4-1 DAAM TEA 2-18 0.3 1 0.1 3-2 4-1
DAAM TEA DAAM, DMAAM, and TEA respectively represent diacetone
acrylamide diacetone methcrylamide, and tetraethyl ammonium
ion.
Preparation of Pigment Dispersions 2-1 to 2-16
[0222] Pigment dispersions 2-1 to 2-16 were obtained in the same
manner as in the pigment dispersion 1-1 except that each of the 10
percent by mass aqueous solutions of the copolymers 2-1 to 2-16 was
used instead of the 10 percent by mass aqueous solution the
Copolymer 1-1.
Preparation of Pigment Dispersions 2-17 to 2-19
[0223] Pigment dispersions 2-17 to 2-19 were respectively obtained
in the same manner as the pigment dispersions 1-14 to 1-16 except
that the 10 percent by mass aqueous solutions of the copolymer 2-1
was used instead of the 10 percent by mass aqueous solution the
copolymer 1-1.
Preparation of Pigment Dispersions 2-20 to 2-22
[0224] The pigment dispersions 1-17 to 1-19 were respectively used
as the pigment dispersions 2-20 to 2-22.
[0225] The ingredients of the pigment dispersions 2-1 to 2-22 are
shown in Table 5.
TABLE-US-00005 TABLE 5 Pigment dispersion 2 Copolymer 2 Pigment
Storage stability 2-1 2-1 Black A 2-2 2-2 Black A 2-3 2-3 Black A
2-4 2-4 Black B 2-5 2-5 Black A 2-6 2-6 Black A 2-7 2-7 Black A 2-8
2-8 Black A 2-9 2-9 Black A 2-10 2-10 Black A 2-11 2-11 Black A
2-12 2-12 Black A 2-13 2-13 Black B 2-14 2-14 Black B 2-15 2-15
Black A 2-16 2-16 Black B 2-17 2-1 Cyan A 2-18 2-1 Magenta A 2-19
2-1 Yellow A 2-20 -- Black -- 2-21 -- Cyan -- 2-22 -- Magenta
--
[0226] As seen in Table 5, it is confirmed that the pigment
dispersions 2-1 to 2-22 have excellent storage stability.
Examples 2-1 to 2-16
[0227] Inks were obtained in the same manner as in Example 1-1
except that each of the pigment dispersions 2-1 to 2-16 was used
instead of the pigment dispersion 2-1.
Examples 2-17 to 2-19
[0228] Inks were obtained in the same manner as in Examples 1-14 to
1-16 except that the pigment dispersions 2-17 to 2-19 were
respectively used instead of the pigment dispersions 1-14 to
1-16.
Example 2-20
[0229] Ink was obtained in the same manner as in Example 1-17
except that the pigment dispersion 2-20 and 30 percent by mass
aqueous solution of the copolymer 2-17 were used instead of the
pigment dispersion 1-17 and 30 percent by mass aqueous solution of
the copolymer 1-14.
Example 2-21
[0230] Ink was obtained in the same manner as in Example 1-18
except that the pigment dispersion 2-21 and 30 percent by mass
aqueous solution of the copolymer 2-18 were used instead of the
pigment dispersion 1-18 and 30 percent by mass aqueous solution of
the copolymer 1-15.
Example 2-22
[0231] Ink was obtained in the same manner as in Example 1-19
except that the pigment dispersion 2-22 and 30 percent by mass
aqueous solution of the copolymer 2-18 were used instead of the
pigment dispersion 1-19 and 30 percent by mass aqueous solution of
the copolymer 1-15.
Example 2-23
[0232] Ink was obtained in the same manner as in Example 1-20
except that the pigment dispersion 2-17 and 30 percent by mass
aqueous solution of the copolymer 2-18 were used instead of the
pigment dispersion 1-14 and 30 percent by mass aqueous solution of
the copolymer 1-15.
[0233] The ingredients of Examples 2-1 to 2-23 are shown in Table
6.
TABLE-US-00006 TABLE 6 Example 2 Pigment dispersion Copolymer 2 2-1
2-1 -- 2-2 2-2 -- 2-3 2-3 -- 2-4 2-4 -- 2-5 2-5 -- 2-6 2-6 -- 2-7
2-7 -- 2-8 2-8 2-9 2-9 -- 2-10 2-10 -- 2-11 2-11 -- 2-12 2-12 --
2-13 2-13 -- 2-14 2-14 -- 2-15 2-15 -- 2-16 2-16 -- 2-17 2-17 --
2-18 2-18 -- 2-19 2-19 -- 2-20 2-20 2-17 2-21 2-21 2-18 2-22 2-22
2-18 2-23 2-17 2-18
Synthesis of Copolymer 3-1
[0234] 10 percent by mass aqueous solution of the copolymer 3-1 was
obtained in the same manner as the copolymer 1-1 except that 9.40
mmol of the compound represented by the following chemical formula
II was used instead of 9.40 mmol of the compound represented by the
Chemical formula 4-1.
##STR00019##
[0235] The 10 percent by mass aqueous solution of the copolymer 3-1
had a viscosity of 1.7 mPas.
Synthesis of Copolymer 3-2
[0236] 30 percent by mass aqueous solution of the copolymer 3-2 was
obtained in the same manner as the copolymer 1-14 except that 140
mmol of the compound represented by the chemical formula II was
used instead of 140 mmol of the compound represented by the
Chemical formula 4-1. The 30 percent by mass aqueous solution of
the copolymer 3-2 was diluted with water. The 10 percent by mass
aqueous solution of the copolymer 3-2 had a viscosity of 28.5
mPas.
Synthesis of Copolymer 3-3
[0237] 10 percent by mass aqueous solution of the copolymer 3-3 was
obtained in the same manner as the copolymer 2-1 except that 8.51
mmol of the compound represented by the chemical formula II was
used instead of 8.51 mmol of the compound represented by the
Chemical formula 4-1. The 10 percent by mass aqueous solution of
the copolymer 3-3 had a viscosity of 1.9 mPas.
Synthesis of Copolymer 3-4
[0238] 30 percent by mass aqueous solution of the copolymer 3-4 was
obtained in the same manner as the copolymer 2-17 except that 129.5
mmol of the compound represented by the chemical formula II was
used instead of 129.5 mmol of the compound represented by the
Chemical formula 4-1. The 30 percent by mass aqueous solution of
the copolymer 3-4 was diluted with water. The 10 percent by mass
aqueous solution of the copolymer 3-4 had a viscosity of 32.3
mPas.
Preparation of Pigment Dispersions 3-1 to 3-4
[0239] Pigment dispersions 3-1 to 3-4 were respectively obtained in
the same manner as the pigment dispersions 1-1 and 1-14 to 1-16
except that the copolymer 3-1 was used instead of the copolymer
1-1.
Preparation of Pigment Dispersions 3-5 and 3-6
[0240] The pigment dispersions 1-18 and 1-19 were respectively used
as the pigment dispersions 3-5 and 3-6.
Preparation of Pigment Dispersions 3-7 to 3-10
[0241] Pigment dispersions 3-7 to 3-10 were respectively obtained
in the same manner as the pigment dispersions 2-1 and 2-17 to 2-19
except that the copolymer 3-3 was used instead of the copolymer
2-1.
Preparation of Pigment Dispersions 3-11 and 3-12
[0242] The pigment dispersions 1-18 and 1-19 were respectively used
as the pigment dispersions 3-11 and 3-12.
[0243] The ingredients of the pigment dispersions 3-1 to 3-12 are
shown in Table 7.
TABLE-US-00007 TABLE 7 Pigment dispersion 3 Copolymer 3 Pigment
Storage stability 3-1 3-1 Black D 3-2 3-1 Cyan D 3-3 3-1 Magenta E
3-4 3-1 Yellow E 3-5 -- Cyan -- 3-6 -- Magenta -- 3-7 3-3 Black E
3-8 3-3 Cyan D 3-9 3-3 Magenta E 3-10 3-3 Yellow D 3-11 -- Cyan --
3-12 -- Magenta --
[0244] As seen in Table 7, the pigment dispersions 3-1 to 3-4, and
3-7 to 3-10 have a low level of storage stability since the
copolymers 3-1 and 3-3 have no structure unit represented by the
Chemical formula 2.
Comparative Examples 1 to 4
[0245] Inks were obtained in the same manner as in Examples 1-1 and
Examples 1-14 to 1-16 except that the pigment dispersions 3-1 to
3-4 were respectively used instead of the pigment dispersions 1-1
and 1-14 to 1-16.
Comparative Example 5
[0246] Ink was obtained in the same manner as in Example 1-18
except that the pigment dispersion 3-5 and 30 percent by mass
aqueous solution of the copolymer 3-2 were used instead of the
pigment dispersion 1-18 and 30 percent by mass aqueous solution of
the copolymer 1-15.
Comparative Example 6
[0247] Inks were obtained in the same manner as in Examples 1-18
and 1-19 except that the pigment dispersion 3-6 and 30 percent by
mass aqueous solution of the copolymer 3-2 were used instead of the
pigment dispersion 1-19 and 30 percent by mass aqueous solution of
the copolymer 1-15.
Comparative Example 7
[0248] Ink was obtained in the same manner as in Example 1-20
except that the pigment dispersion 3-2 and 30 percent by mass
aqueous solution of the copolymer 3-2 were used instead of the
pigment dispersion 1-14 and 30 percent by mass aqueous solution of
the copolymer 1-15.
Comparative Examples 8 to 11
[0249] Inks were obtained in the same manner as in Examples 2-1 and
Examples 2-17 to 2-19 except that the pigment dispersions 3-7 to
3-10 were respectively used instead of the pigment dispersions 2-1
and 2-17 to 2-19.
Comparative Example 12
[0250] Ink was obtained in the same manner as in Example 2-21
except that the pigment dispersion 3-11 and 30 percent by mass
aqueous solution of the copolymer 3-4 were used instead of the
pigment dispersion 2-21 and 30 percent by mass aqueous solution of
the copolymer 2-18.
Comparative Example 13
[0251] Ink was obtained in the same manner as in Example 2-22
except that the pigment dispersion 3-12 and 30 percent by mass
aqueous solution of the copolymer 3-4 were used instead of the
pigment dispersion 2-22 and 30 percent by mass aqueous solution of
the copolymer 2-18.
Comparative Example 14
[0252] Ink was obtained in the same manner as in Example 2-23
except that the pigment dispersion 3-6 and 30 percent by mass
aqueous solution of the copolymer 3-4 were used instead of the
pigment dispersion 2-17 and 30 percent by mass aqueous solution of
the copolymer 2-18.
[0253] The ingredients of Comparative Examples 1 to 14 are shown in
Table 8.
TABLE-US-00008 TABLE 8 Comparative Example Pigment dispersion 3
Copolymer 3 1 3-1 -- 2 3-2 -- 3 3-3 -- 4 3-4 -- 5 3-5 3-2 6 3-6 3-2
7 3-2 3-2 8 3-7 -- 9 3-8 -- 10 3-9 -- 11 3-10 -- 12 3-11 3-4 13
3-12 3-4 14 3-6 3-4
[0254] Next, storage stability, image density, and beading of the
inks are evaluated.
[0255] Storage Stability of Ink
[0256] A glass container was filled with the ink and stored at 70
degrees C. for one week. The viscosity change rate was obtained
from the following relation:
[0257] |(Viscosity of ink after storage)-(Viscosity of ink before
storage)|/(Viscosity of ink before storage).times.100, to evaluate
the storage stability. The viscosity of the ink at 25 degrees C.
was measured at 50 rpm by using a viscometer (RE80L, manufactured
by TOM SANGYO CO., LTD.). The change rate of the viscosity was
rated as follows:
A: Less than 5% B 5% to less than 8% C: 8% to less than 10% D: 10%
to less than 30% E: 30% or greater
[0258] Discharging Stability
[0259] First, the viscosity .eta. (0 percent) of the initial ink
was measured. After 30 g of the ink was charged in a 50 mL glass
beaker and left in the environment of 50 degrees C. and 10 percent
RH to evaporate water, the viscosity .eta. (30 percent) of the ink
that had lost 30 percent from the initial mass was measured. The
viscosity of the ink at 25 degrees C. was measured at 50 rpm by
using a viscometer (RE80L, manufactured by TOKI SANGYO CO., LTD.).
Furthermore, the rate of .eta. (30 percent)/.eta. (0 percent) was
calculated to evaluate the discharging stability. Evaluation
criteria of the rate are as follows:
level AA: less than 10 level A: from 10 to less than 30 level B:
from 30 to less than 100 level C: 100 or greater.
[0260] Image Density
[0261] An inkjet printer (IPSiO GX5000, manufactured by Ricoh
Company Ltd.) was filled with the ink at 23 degrees C. and 50% RH.
Thereafter, a chart on which general symbols of 64 point JIS X 0208
(1997) and 2223 were listed was created and printed on recording
media by utilizing Microsoft Word 2000 (manufactured by Microsoft
Corporation) and the color of the area on which the general symbols
were printed were measured by using X-Rite 938 (manufactured by
X-Rite Inc.) to evaluate image density. The print mode used was: A
modified mode in which the mode "Plain Paper--Standard Fast" was
modified to the mode "No Color Calibration" from the user setting
for plain paper in the driver installed onto the printer. In
addition, the recording media were Xerox 4200 (hereinafter referred
to as plain paper 1) (manufactured by Xerox Corporation) and
MyPaper (hereinafter referred to as plain paper 2) (manufactured by
Ricoh Company Ltd.). Moreover, the symbols of JIS X 0208 (1997) and
2223 were squares with the inside thereof entirely painted. The
level of the image density was evaluated according to the following
criteria:
A: Image density is 1.25 or greater B: 1.20 to less than 1.25 C:
1.10 to less than 1.20 D: Less than 1.10 E: Unable to print because
pigment was gelated and not dispersed
[0262] Beading
[0263] The general symbols of JIS X 0208 (1997) and 2223 of were
printed in the same manner as for the image density except that the
print mode was changed to the mode "gloss paper--fast" using coated
paper (LumiArt Gloss 90 GSM.TM., manufactured by Stora Enso Japan
K.K.) as the recording medium and beading of the printed symbols
was evaluated. The level of the beading was evaluated for the rate
of the area to which beading occurred to the area on which the
general symbols were printed according to the following
criteria:
A: Less than 10 percent B: 10 percent to less than 20 percent C: 20
percent to less than 40 percent D: 40 percent to less than 90
percent E: 90 percent or greater F: unable to print because pigment
was gelated and not dispersed
[0264] Next, evaluations of the inks about storage stability, image
density, and beading are shown in Tables 9 to 11.
TABLE-US-00009 TABLE 9 Storage Discharging Image density Example 1
stability stability Plain paper 1 Plain paper 2 Beading 1-1 A A A A
A 1-2 B B A A A 1-3 A B A A A 1-4 B B A A B 1-5 A A A B A 1-6 A B A
B A 1-7 A B B A A 1-8 A B B A A 1-9 A A A B A 1-10 B B A A A 1-11 B
B B A A 1-12 B B A A A 1-13 B B B A B 1-14 A B A A A 1-15 A B A A A
1-16 A B A A A 1-17 B B B B A 1-18 B B B B A 1-19 B B B B A 1-20 A
B A A A
TABLE-US-00010 TABLE 10 Storage Discharging Image density Example 2
stability stability Plain paper 1 Plain paper 2 Beading 2-1 A AA A
A A 2-2 B AA A A A 2-3 B AA A A A 2-4 B AA A A A 2-5 A AA A A B 2-6
A AA A B A 2-7 A AA A A B 2-8 A AA A A B 2-9 A AA A B A 2-10 A AA A
B A 2-11 A A A A A 2-12 A AA B B B 2-13 B A A A A 2-14 B A A A A
2-15 B A A A A 2-16 B A A B A 2-17 A AA A A A 2-18 A AA A A A 2-19
A AA A A A 2-20 B A B B A 2-21 B A B B A 2-22 B A B B A 2-23 A AA A
A A
TABLE-US-00011 TABLE 11 Image density Comparative Storage
Discharging Plain Example stability stability paper 1 Plain paper 2
Beading 1 D C C C C 2 D C C C E 3 E C F F F 4 E C F F F 5 D C B C E
6 C C D C D 7 D C C C D 8 E C D D E 9 D C C D E 10 E C C C C 11 D C
C C D 12 D C C C B 13 D C C D C 14 D C C C C
[0265] As seen in the results shown in Tables 9 and 10, it is
confirmed that the inks of Examples 1-1 to 1-20 and 2-1 to 2-23
have excellent storage stability, discharging stability, and image
density on plain paper and reduce the occurrence of beading when
images are formed on coated paper.
[0266] As seen in Table 11, the storage stability, discharging
stability, and image density on plain paper of the inks of
Comparative Examples 1 to 14 deteriorated and beading occurred to
images formed on coated paper.
[0267] That is, the ink of the present disclosure has excellent
storage stability, discharging stability, and image density on
plain paper so that occurrence of beading of images formed on
coated paper is inhibited by using the ink of the present
disclosure.
[0268] Having now fully described embodiments of the present
invention, it will be apparent to one of ordinary skill in the art
that many changes and modifications can be made thereto without
departing from the spirit and scope of embodiments of the invention
as set forth herein.
* * * * *