JPS6042833B2 - ink composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high concentration recording ink composition particularly useful as an inkjet recording ink.

The first object of the present invention is to provide an ink composition (color ink and achromatic ink) having necessary physical properties and sufficient density by containing a hydrophobic dye and a water-soluble dye in the same ink. It is in.

When attempting to form an image with a required density using a very small amount of ink, as in the case of inkjet recording, it is necessary to increase the dye density in the ink. In the case of conventional inks using water-soluble dyes, increasing the dye concentration causes the problem of dye precipitation, which causes various practical problems.
Taking the case of inkjet recording as an example, the above problem is that in the case of ink or ink using oil-soluble dyes, the viscosity tends to increase when the dye is dissolved in an oil-based solvent at a high concentration, and low viscosity It is unsuitable for purposes requiring physical properties.
In this case, even if a low viscosity solution such as acetone or ethyl acetate is used in combination, changes in physical properties due to the volatilization of the solvent still pose a practical problem. The ink of the present invention is an ink that solves the above problems. That is, since it is an aqueous medium, it has physical properties almost similar to water, and the ink density can be made higher by the amount of the hydrophobic dye impregnated into the vinyl polymer fine particles than in the case of a water-soluble dye alone. A second object of the present invention is to expand the range of hue control required for ink.

In other words, it is not only possible to use a combination of water-soluble dyes and oil-soluble dyes, but also to change the ratio of the combination of each dye, which allows for a wider range of hues compared to conventional inks that use only water-soluble and oil-soluble dyes. It is possible to change it to Furthermore, by combining dyes with different uses, such as combining an infrared absorbing dye with a normal color ink, it is also possible to expand the range of uses of the ink. The vinyl polymer particles used in the present invention do not substantially dissolve or swell in water, and have the property of not substantially dissolving but swelling in the organic solvent used as a solvent for hydrophobic dyes. It is characterized by having

Such vinyl polymer particles can be produced by emulsion polymerization of vinyl monomers. Suitable monomers include (a) a general formula (wherein R is hydrogen or an alkyl group having 1 to 5 carbon atoms, R''
(1) Acrylic acid ester (e.g. methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, etc.) , and (Ii) α-substituted acrylic esters (e.g. methyl methacrylate, butyl methacrylate, octyl methacrylate, etc.) (b
) about 2 to 2.5% by weight of carboxylic acid groups or sulfonic acid groups or ammonium or alkali metal salts thereof;
, preferably about 2 to 10% by weight of a hydrophilic vinyl monomer (c) that is crosslinkable to produce a cured material by reaction with a curing agent (aldehydes such as formaldehyde, succinic aldehyde, vinyl sulfone, aziridine, etc.) (d) a hydrophilic vinyl monomer selected from the group of monomers having a sulfonic acid group attached to a terminal carbon atom; (e) curing; curable or crosslinkable vinyl monomer containing active methylene groups (f) acrylamide (butylacrylamide, hexylacrylamide, etc.) (g) α
Monosubstituted acrylamide (butyl methacrylamide, dibutyl methacrylamide, etc.) (5) Vinyl ester (vinyl acetate, vinyl oxate, etc.) (1) Vinyl halide (vinyl chloride, etc.) (j) Vinyl ether (vinyl ethyl ether, vinyl octyl) ether, etc.) (k) Styrene, α
Monosubstituted styrene (α-methylstyrene, etc.) 0) Nuclearly substituted styrene derivatives (hydroxystyrene, chlorostyrene,
methylstyrene, etc.) (m) Ethylene, propylene, butylene, butadiene, acrylonitrile, etc.

These may be used alone or in combination of two or more.

Furthermore, vinyl monomers other than those mentioned above may be mixed as minor components within the range that maintains the above properties. The vinyl polymer used in the present invention is recommended to have a relatively low elastic modulus, and particularly preferably has a glass transition point of 30° C. or lower.

Polymer latexes typically have at least about 2
Examples include, but are not limited to, latexes comprising the following components containing solids from weight percent to about 2 weight percent. The numbers listed below are the relative weight ratios of the monomers charged to the reactor during latex production.

(a) n-butyl methacrylate 85 sodium 3-methacryloyloxypropane-1-methyl-1-sulfonate 102-acetoacetoxyethyl methacrylate 5 (b) n-butyl acrylate 85 sodium 2-acrylamide 2:102-acrylamide -2-methylpropanesulfonate 5(c)n
-Butyl methacrylate 75 Methyl methacrylate 10 Sodium 2-acrylamide 2-methylpropanesulfonate 10 2-acetoacetoxyethyl methacrylate 5 (d) n-Butyl methacrylate 50 Styrene 40 Sodium 2-acrylamide 2-methylpropanesulfonate The proportion of hydrophobic material impregnated into the 10 vinyl polymer particles is from 2.5 to 75% by weight, preferably from 5 to about 5% by weight.

Hydrophobic dyes used in the present invention include monoazo dyes, anthraquinone dyes, metal complex type monoazo dyes, diazo dyes, phthalocyanine dyes, triallylmethane dyes, and other dyes that are soluble in organic solvents, sublimable dyes, and organic pigments. can give. Examples of the hydrophobic dyes used in the present invention are shown below by color.

Yellowish: C. I. SolventYellOwl9(C
．． I. l39OOA), C. I. SolventYel
lOw2l (C.I.l869O), C. I. SOLV
entYellOw6l, C. I. SolventYe
llOw8O, AizenSpllOnYellOwG
RHspecial (product name, manufactured by Hodogaya Chemical Industries, Ltd.), DiaresinYellOwF (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), DiaresinYellOw
A (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), YellowOw
fluOrG (trade name, manufactured by Sumitomo Chemical Industries, Ltd.).

Orange color: C. I. Solvent Orange (CJ
．． ll92O), C. I. SolventOrange
37, C. I. SolventOrange4O, Di
aresinOrangeK (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), DiaresinOrangeG (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), SunllpIastO
r'Ange3G (product name, manufactured by Sumitomo Chemical Co., Ltd.)
.

Red color: C. I. SOL■EntRed8(C.I.l
27l5), C. I. SolventRed8l, C.
I. SolventRed82,C. I. Solven
tRed84,C. I. 0 to SolventRedlO
rient011Scar1et #308 (product name, manufactured by Orient Chemical Industry Co., Ltd.), SoldanRed3
R (product name, manufactured by Chugai Kasei Co., Ltd.), Diaresin
RedS (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Sum
iplastRedAS (product name, manufactured by Sumitomo Chemical Industries, Ltd.), DiaresinRedK (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), SunllpIastRed3B (product name, manufactured by Mitsubishi Chemical Industries, Ltd.)
Product name (manufactured by Sumitomo Chemical Co., Ltd.), Diaresin
RedEL (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Di
aresinRedH (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), DiaresinRedLM (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), DiaresinRedG (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), AizenSpiION
RedGEHSspecial (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.).

Pink: DiaresinPinkM (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), SumipIastPinkR,
, FF (trade name, manufactured by Sumitomo Chemical Industries, Ltd.).

Purple color: C. I. SolventVlOlet(C.I
．． 42535B), C. I. SolventVlOle
t2l, DiaresinViOletA (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Diaresin IOle
tD (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Sunll
plastViOletRR (trade name, manufactured by Sumitomo Chemical Industries, Ltd.).

Blue color: C. I. SolventBlue2 (C.I.
42563B), C. I. SolventBlLel
l (C.I.6l525), C.I. I. SolventB
lue25 (C.I.7435O), C.I. I. SOLV
entBlle36, C. l. SOIventBlue
e55, AizenSpilOnBILleGNH (product name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Diaresin
BlueG (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Di
aresinBlueC (trade name, manufactured by Mitsubishi Chemical Corporation), DiaresinBlueJ, . AlH. ．． K
、． N (product name, manufactured by Mitsubishi Chemical Industries, Ltd.), Vall
FastBlue #2604 (trade name, manufactured by Orient Chemical Industry Co., Ltd.).

Greenish: C. I. Solvent Green 3 (C.I.
．． 6l565).

Brown: C. I. SolventBrOwn3(C.I.
．． ll36O), DiaresinBrOwnA (trade name, manufactured by Mitsubishi Chemical Industries, Ltd.). Black color: C. I. S.O.
lventBIack (C.I.26l5O), C.I. I
．． SolventBlack5 (C.I.5O4l5)
,C. I. SolventBlack7 (C.I.5O
4l5), C. I. SolventBlack22,C
．． I. AcidBlaCkl24 (C.I.l2l95
), SumlisOlBlack. ARsOl (product name, manufactured by Sumitomo Chemical Industries, Ltd.), VallFastBIa
ck#1802 (trade name, manufactured by Orient Chemical Industry Co., Ltd.).

Other U.S. Patents No. 3,651,495, U.S. Pat. No. 3,652,284,
No. 3486897, No. 2751298, No. 3506
No. 443 and Product Licensing Index Vol. 92, pp. 108-109 (December 1971), Canadian Patent No. 602607, U.S. Patent No. 3443939, U.S. Patent No. 3443940, U.S. Patent No. 3443941, U.S. Patent No. 372
No. 5062, No. 3415644, No. 3415645, No. 3415646, No. 3647437, and No. 3
635707, Belgian Patent No. 757959, No. 75
It is also possible to use the lipophilic dyes described in No. 7960, No. 810195 and No. 788268.

As the organic solvent for dissolving the hydrophobic dye, alcohol-based, ester-based, ketone-based, ether-based, hydrocarbon-based, oil and fat, and other solvents that are substantially immiscible or partially miscible with water are used.

Specific examples of this solvent include US Pat. No. 2,322,027;
Examples include rubonic acid esters, amides, ethers, ketones, etc., as described in No. 3,676,137. Examples of preferred solvents include di-n-butyl phthalate,
Dioctyl phthalate, dimethoxyethyl phthalate,
Diisooctyl phthalate, dimethoxyethyl phthalate, benzyl phthalate, triphenyl phosphate,
Esters of phthalic acid and phosphoric acid such as tricresyl phosphate, diphenyl monobutyl phosphate, tributyl phosphate, tridecyl phosphate, dibutyl monohexyl phosphate, diphenyl mono-0-chlorophenyl phosphate, and as co-solvents US Pat. No. 3,253,921 , ethyl acetate, butyl acetate, which are described in 3574627, etc.
Nitromethane, chloroform, secondary butanol, methyl isobutyl ketone, β-ethoxyethyl acetate, diethylene glycol monoacetate, diethylene glycol monoethyl ether, tetrahydrofuran, cyclohexanone, dimethylformamide, methanol, dioxane, etc. may be used in combination with the above solvents.

The water-soluble dyes used in the present invention include water-soluble monoazo dyes, anthraquinone dyes, metal complex monoazo dyes,
Phthalocyanine dyes, triallylmethane dyes, and other dyes are used.

Examples of water-soluble dyes used in the present invention are shown below by color.

Yellowish: C. I. DirectYellOw33(C.
I. 29O2O), C. I. DirectYellOw
39sC. I. DirectYellOw44 (C.I.
．． 29OOOO), C. l. DirectYellOw9
f3sC. I. AcidYellOwlgsC. I. A
cidYellOw2λC. I. AcidYellOw2＼C. I. AcidYellOwOtoriC. I. AcidYellOwl27.

Red color: C. I. DirectRed79 (C.I.2
9O65), C. I. DirectRed8l(C.I.
．． 28l6O), C. I. DirectRed83(C
．． I. 29225), C. I. AcidRed37,C
．． I. AcidRedllF3sC. I. AcidRedl58 (C.I.2O53O)
,C. I. AcidRed249 (C.I.l8l34
), C. l. AcidViOlet9OO blue color: C.
I. DirectBlue7l (C.I.34l4O)
,C. I. DirectBlue98 (C.I.23l
55), C. I. DirectBlue9C. I. D
directBIue2O2, C. I. AcidBlue27 (C.I.6ll35
), C. I. AcidBlue23 (C.I.6ll2
5), C. I. AcidBlue43 (C.I.63O
OO), C. I. AcidBlue78 (CJ.62l
O5), C. I. AcidBlue82.

Black color: C. I. Direct Blackl9 (C.I.
．． 35255), C. I. DirectBlack32
(C.I.3544O), 1C. I. DirectB1
ack10 Saka C. I. Acid Blackl (C.I.
2O47O), C. I. AcidBlack3l (C.
I. l758O), C. I. AcidBlue24(C
．． I. 2637O), C. I. AcidBlaCk52
.

The ink composition of the present invention will be explained below with reference to Examples.

Example 1 Yellow dye C. l. DisperseYellO
w42 (C.I.lO338)3y was heated and dissolved in 15 ml of tributyl phosphate, and this was mixed into a latex (polymer 2) produced from monomers having the composition (a) above.
Heel weight %) was added to 100ml and mixed with a high speed mixer.

The resulting aqueous dispersion of dye-impregnated vinyl polymer particles was further treated with C.I. I. 2f of AcidYellOwl9 was added and dissolved to prepare a stable high-density color ink with a real dye concentration of about 5%. The viscosity of the obtained jet ink composition was 3.0 Cp. The surface tension was 30 dynes/Cm. Example 2 Red dye C. I. Solvent Red8 (C.
I. 100ml of latex (polymer 20% by weight) produced from monomers having the above composition by heating and dissolving l27l5)5y in 20ml of tricresyl phosphate.
Add it to 1 and use a high speed mixer to make 10,000! 'Pm at 2
Stir for a minute.

The resulting aqueous dispersion of dye-impregnated vinyl polymer particles was further treated with C.I. I. A high-density color ink with an effective dye concentration of about 7% was prepared by dissolving DirectRed8l2y.
The resulting ink was not only stable for long periods of time during storage at room temperature without solidifying, but also produced high-quality images without clogging the nozzles when used in ink jets, air brushes, and spray guns. . Example 3 Blue dye C. I. SolventBIue2 (C.I.
42563B) 3y is heated and dissolved in 10y of dibutyl phthalate and 20y of ethyl acetate.

Claims (1)

[Claims] 1 Polymer fine particles prepared by emulsion polymerization of vinyl monomers, which have a glass transition point of 30°C or less, are substantially insoluble in water, are non-swellable, and swell in the solvent of a hydrophobic dye. 1. An ink composition characterized by dispersing vinyl polymer fine particles, which are aqueous, in an aqueous medium, containing a water-soluble dye in the aqueous medium, and containing a hydrophobic dye solution in the vinyl polymer fine particles.