JP5560529B2 - Ink composition - Google Patents

Description

  The present invention relates to providing an ink composition comprising a pigment, a vinyl chloride resin and an organic solvent and having excellent storage stability.

  Conventionally, gravure printing for soft packaging materials, flexographic printing for sanitary, silk screen printing for metal plates, inkjet printing for indoor and outdoor advertising, etc. are generally known as printing methods for non-absorbent substrates.

  In particular, in inkjet printing that prints images and characters using minute ink droplets ejected from the nozzles of an inkjet head, inkjet printers that can handle A-0 size have been developed in recent years for outdoor applications such as outdoor posters. Ink jet printing inks that are excellent in water resistance, weather resistance, and friction resistance have been actively developed against the background of the increase in usage environment.

  In particular, ink-jet printing inks used for the sign industry are mainly solvent ink-jet inks that use organic solvents as the solvent, instead of water-based ink-jet inks in which colorants such as water-soluble dyes are added to general water. It is used. For example, for printing on the surface of a polyvinyl chloride sheet or the like, which is used as a medium for outdoor advertising, etc., a pigment having excellent weather resistance, a binder resin that firmly adheres the pigment to the sheet surface, A pigment ink composition containing an organic solvent capable of dissolving the binder resin is considered suitable.

  However, when a vinyl chloride resin is used as the binder resin, it is generally known that the dehydrochlorination reaction proceeds because the resin is unstable to heat and light and easily decomposes (see Document 1). . Therefore, since the pH of the ink moves to the acidic side, increasing the viscosity of the ink, deterioration of printability, corrosion and deterioration of the inkjet head and printer members, yellowing of the ink coating film, etc. are problems. Yes.

Therefore, conventionally, in order to remove or reduce the degradation factors mainly including dehydrochlorination reaction of the vinyl chloride resin due to heat or light degradation, it is essential to add a stabilizer (References 1-2). , See Patent Document 1).
Notes on the use of plastic additives (May 20, 2001, first edition, fifth edition, published by Industrial Research Co., Ltd.) Practical Plastic Encyclopedia-Materials (April 20, 1996, first edition, third edition, published by Sangyo Kenkyukai Co., Ltd.) JP, 2000-26687, A While it is also known to add the stabilizer to an ink-jet ink composition using a vinyl chloride resin as a binder resin (see Patent Document 2), the present inventor. As a result of these studies, it was insufficient to suppress dehydrochlorination, and the above problems were not solved. JP 2008-13714 A

  The present invention has been made in view of the above problems, and its purpose is to suppress dehydrochlorination reaction when using a vinyl chloride resin as a binder resin in an ink composition, and to provide excellent storage stability and printing. The object is to provide a pigment ink composition capable of realizing suitability.

  The above object of the present invention is achieved by the following configurations.

An ink composition comprising at least a pigment, a vinyl chloride resin and an organic solvent, comprising a polyvalent carboxylic acid or an anhydride thereof.
Furthermore, an ink composition comprising any one or more of the solvents represented by the general formulas (1) to (4) as an organic solvent.
R ₁ CO (OR ₂ ) _Z OR ₃ (1) R ₄ CO (OR ₅ ) _Z OCOR ₆ (2)
R ₇ (OR ₈ ) _Z OR ₉ (3) R ₁₀ COOR ₁₁ (4)
(Wherein R _2, R _{5 and} R ₈ are each independently an ethylene group or a propylene group, R ₁ , R ₃ ,
R ₄ and R ₆ are each independently an alkyl group having 1 to 4 carbon atoms, R ₇ and R ₉ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₁₀ is a 2-hydroxyethyl group, R ₁₁ represents an alkyl group having 1 to 8 carbon atoms, and Z represents an integer of 1 to 3. )
Furthermore, a part of the organic solvent contains a nitrogen-containing, sulfur-containing or lactone-based solvent.
Furthermore, the content of the polyvalent carboxylic acid or its anhydride contained in the ink composition is less than 5% by weight in the ink.
An ink composition further comprising a dispersant in the ink composition.
Furthermore, the ink composition is an ink-jet ink.

  According to the present invention, even when a vinyl chloride resin is used as a binder resin in an ink composition, excellent storage stability and printability can be realized by containing a polyvalent carboxylic acid or its anhydride. Ink jet ink compositions are provided.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The ink composition of the present invention comprises a pigment ink composition comprising a pigment having excellent weather resistance, a binder resin for firmly adhering the pigment to the surface of a print medium, and an organic solvent capable of dissolving the binder resin. It is. Examples of the binder resin having excellent adhesion to the print medium surface include acrylic resins, styrene-acrylic resins, styrene-maleic resins, rosin resins, rosin ester resins, ethylene-vinyl acetate resins, petroleum Resin, coumarone indene resin, terpene phenol resin, phenol resin, urethane resin, melamine resin, urea resin, epoxy resin, cellulose resin, xylene resin, alkyd resin, aliphatic hydrocarbon resin, butyral resin, maleic acid Resin, fumaric acid resin, vinyl chloride resin and the like can be used. Among them, vinyl chloride resin is widely used as a printing medium for solvent inkjet inks, has good adhesion to the surface of polyvinyl chloride sheets, etc., and has good chemical and oil resistance during coating. Therefore, it is more preferable. In addition, when vinyl acetate is copolymerized with vinyl chloride, the solubility of the binder resin in the solvent can be improved, or the abrasion resistance of the ink coating film printed on the polyvinyl chloride sheet or the like can be improved. It is particularly preferable to use it as a binder resin for solvent ink jet ink compositions.

  Specific examples of the vinyl chloride resin used in the present invention include Yuker Solution vinyl resins VYHD, VYHH, VMCA, VROH, VYLF-X manufactured by Dow Chemicals, and sorbine resins CL, CNL, C5R, TA3 manufactured by Nissin Chemical Industry. TA5R, vinyl resins E15 / 45, H14 / 36, H40 / 43, E15 / 45M and E15 / 40M manufactured by Wacker. The resin is preferably contained in the ink in an amount of 0.1 to 10% by weight. When the addition amount is 0.1% by weight or less in the ink, the adhesion to the surface of the printing medium is poor, and the durability of the coating film is reduced. Since it falls, it is not preferable.

  Moreover, you may use together the said vinyl chloride resin and other resin. Usable resins include acrylic resin, styrene-acrylic resin, styrene-maleic resin, rosin resin, rosin ester resin, ethylene-vinyl acetate resin, petroleum resin, coumarone indene resin, terpene phenol Resin, phenol resin, urethane resin, melamine resin, urea resin, epoxy resin, cellulose resin, xylene resin, alkyd resin, aliphatic hydrocarbon resin, butyral resin, maleic acid resin, fumaric acid resin and the like. Specific examples of the resin include Superester 75 manufactured by Arakawa Chemical Co., Ltd., Ester Gum HP, Malkid 33, YS Polystar T80 manufactured by Yasuhara Co., Ltd., Hirtts HRT200X manufactured by Mitsui Chemicals, Inc. be able to.

  However, the vinyl chloride resin used as the binder resin is unstable to heat and light and easily decomposes, so that a dehydrochlorination reaction proceeds. Therefore, solvent ink-jet ink compositions containing vinyl chloride resins tend to dehydrochlorinate in the vinyl chloride resin during long-term storage, and the ink pH tends to shift to the acidic side. is there. Therefore, the dispersion stability of the pigment is broken, the pigment is aggregated, the ink viscosity is increased, the pigment is settled, and the like. In addition, when the ink composition for solvent ink jet in which the ink pH has shifted to the acidic side is used for printing, corrosion and deterioration of metal members, resin members, rubber members, adhesives, etc. used in ink jet heads and printer members cause. In addition, there are various problems such as yellowing of the ink coating due to the progress of the dehydrochlorination reaction of the vinyl chloride resin.

  Accordingly, as a result of various studies, the present inventors have found that when the vinyl chloride resin is used in the ink composition, the vinyl chloride by storage over time is contained by adding a polyvalent carboxylic acid or its anhydride. It has been found that a pigment ink composition for ink jet recording that can suppress the dehydrochlorination reaction of a resin and can realize excellent storage stability and printing stability has been completed, and the present invention has been completed.

  In the present invention, a polyvalent carboxylic acid or an anhydride thereof is added as a stabilizer in order to suppress the dehydrochlorination reaction due to the aging of the vinyl chloride resin. The molecular weight of the polyvalent carboxylic acid or anhydride thereof is preferably 200 or less in consideration of solubility in a solvent. For example, citric acid, fumaric acid, maleic anhydride, phthalic acid, succinic acid, succinic anhydride and the like can be raised. Among these, citric acid is particularly preferable in consideration of solubility in a solvent and safety. The amount added is preferably less than 5% by weight in the ink, more preferably less than 3% by weight, and even more preferably less than 1% by weight. When these polyvalent carboxylic acids or anhydrides are not added, the dehydrochlorination reaction of the vinyl chloride resin is promoted by storing the ink with time, and problems such as thickening of ink viscosity and unstable printing occur. Addition of 5% by weight or more is not preferable because the chemical resistance, oil resistance, and abrasion resistance of the ink coating film are lowered.

  In addition, in order to remove or reduce the degradation degradation factor mainly composed of dehydrochlorination reaction due to heat or light degradation of the vinyl chloride resin, addition of a stabilizer is essential. For example, composite metal soaps such as Ba, Zn, Ca, organotin stabilizers, lead stabilizers, epoxy compounds, organophosphate compounds, β-diketone compounds, polyhydric alcohol compounds, inorganic compounds, etc. are used. It has been.

Based on such information, the present inventors have not achieved excellent storage stability although a metal compound or an organic phosphate compound is added as a stabilizer to the ink-jet ink composition.
In addition, if a metal compound or organophosphate compound is added as a stabilizer, it may appear as a precipitate in the ink jet head nozzle, which may cause ejection failure such as deflection or non-ejection, and safety. Therefore, there are many problems such as the inability to easily use metal compounds. Therefore, the present situation is that a solvent inkjet ink composition that has both excellent storage stability and printing stability has not yet been obtained.

As the organic solvent used in the present invention, an organic solvent having a boiling point of 140 ° C. or higher at 1 atm is preferable, and a flash point of 60 ° C. or higher is more preferable.
As such a solvent, there are solvents represented by the following general formulas (1) to (4).

R ₁ CO (OR ₂ ) _Z OR ₃ (1) R ₄ CO (OR ₅ ) _Z OCOR ₆ (2)
R ₇ (OR ₈ ) _Z OR ₉ (3) R ₁₀ COOR ₁₁ (4)
(Wherein R _2, R _{5 and} R ₈ are each independently an ethylene group or a propylene group, R ₁ , R ₃ ,
R ₄ and R ₆ are each independently an alkyl group having 1 to 4 carbon atoms, R ₇ and R ₉ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₁₀ is a 2-hydroxyethyl group, R ₁₁ represents an alkyl group having 1 to 8 carbon atoms, and Z represents an integer of 1 to 4. )

  Solvents corresponding to general formula (1) include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl. Ether acetate, dipropylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol monoethyl ether propionate, ethylene glycol monobutyl ether propionate, diethylene glycol monomethyl ether propionate, diethylene glycol mono Chill ether propionate, diethylene glycol monobutyl ether propionate, propylene glycol monomethyl ether propionate, dipropylene glycol monomethyl ether propionate, ethylene glycol monomethyl ether butyrate, ethylene glycol monoethyl ether butyrate, ethylene glycol monobutyl ether butyrate And glycol monoacetates such as dirate glycol, diethylene glycol monomethyl ether butyrate, diethylene glycol monoethyl ether butyrate, diethylene glycol monobutyl ether butyrate, propylene glycol monomethyl ether butyrate and dipropylene glycol monomethyl ether butyrate.

  Solvents corresponding to the general formula (2) include ethylene glycol diacetate, diethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, ethylene glycol propionate. Butyrate, ethylene glycol dipropionate, ethylene glycol dibutyrate, diethylene glycol acetate propionate, diethylene glycol butyrate, diethylene glycol propionate butyrate, diethylene glycol dipropionate, diethylene glycol dibutyrate, propylene glycol acetate propionate, propylene glycol acetate Butyrate, propylene glycol Propionate butyrate, propylene glycol dipropionate, propylene glycol dibutyrate, dipropylene glycol acetate propionate, dipropylene glycol acetate butyrate, dipropylene glycol propionate butyrate, dipropylene glycol dipropionate, There are glycol diacetates such as dipropylene glycol dibutyrate.

  Solvents corresponding to general formula (3) include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, diethylene glycol monoethyl. Ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, propylene glycol n-propyl ether, triethylene glycol Monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, there is a glycol ether such as tetraethylene glycol diethyl ether.

  Examples of the solvent corresponding to the general formula (4) include esters such as methyl lactate, ethyl lactate, propyl lactate, and butyl lactate.

  Among these, from the viewpoint of low odor and resin solubility, a (poly) ethylene glycol diether solvent represented by the general formula (3) is preferable.

  In consideration of safety and health, it is particularly preferable to use diethylene glycol diethyl ether from the viewpoint of harmfulness such as acute toxicity, mutagenicity, carcinogenicity, and reproductive toxicity.

  In addition to the general formulas (1) to (4), which are organic solvents in the present invention, the addition of a nitrogen-containing, sulfur-containing, or lactone-based solvent can dissolve the surface of the printing medium, so that the fixability is improved. , Weather resistance and the like can be improved. Examples include 3-methyloxazolidinone, 3-ethyloxazolidinone, dimethyl sulfoxide, 1-methyl-2-pyrrolidone, γ-butyrolactone, ε-caprolactone, and the like. The addition amount is preferably 1 to 20%, preferably 1 to 10%, more preferably 3 to 9%.

  As the pigment used in the present invention, various pigments used in printing inks, paints and the like can be used. When these pigments are represented by color index, Pigment Black 7, Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 60, Pigment Green 7, 36, Pigment Red 9, 48, 49 , 52, 53, 57, 97, 122, 149, 168, 177, 178, 179, 206, 207, 209, 242, 254, 255, pigment violet 19, 23, 29, 30, 37, 40, 50, pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151 , 154, 155, 166, 168, 180, 185, 213, Pigment Orange 36, 43, 51, 5 , Such as 59,61,71,74, and the like. As for carbon black, any carbon black such as neutral, acidic and basic can be used. The pigment is desirably contained in the ink in an amount of 0.1 to 10% by weight.

  In the present invention, it is preferable to add a dispersant in order to improve the dispersibility of the pigment and the storage stability of the ink. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a salt of a long chain polyaminoamide and a polar acid ester, a high molecular weight unsaturated acid ester, Molecular copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate salt, polyoxyethylene alkyl phosphate ester, polyoxyethylene nonyl Phenyl ether, stearylamine acetate, etc. can be used.

  Specific examples of the dispersant include “Anti-Terra-U (polyaminoamide phosphate)”, “Anti-Terra-203 / 204 (high molecular weight polycarboxylate)”, “Disperbyk-101” (polyamino) manufactured by BYK Chemie. Amide phosphate and acid ester), 107 (hydroxyl group-containing carboxylic acid ester), 110, 111 (copolymer containing acid group), 130 (polyamide), 161, 162, 163, 164, 165, 166, 170 (high Molecular copolymer) ”,“ 400 ”,“ Bykumen ”(high molecular weight unsaturated acid ester),“ BYK-P104, P105 (high molecular weight unsaturated acid polycarboxylic acid) ”,“ P104S, 240S (high molecular weight unsaturated) Acid polycarboxylic acid and silicon) "," Lactimon (long-chain amine and unsaturated acid polycarbonate) Rubonic acid and silicon).

  Also, “Efka CHEMICALS” “Efka 44, 46, 47, 48, 49, 54, 63, 64, 65, 66, 71, 701, 764, 766”, “Efka Polymer 100 (modified polyacrylate), 150 (aliphatic) System modified polymer), 400, 401, 402, 403, 450, 451, 452, 453 (modified polyacrylate), 745 (copper phthalocyanine system) "," Floren TG-710 (urethane oligomer) "," Flownon "manufactured by Kyoeisha Chemical Co., Ltd. “SH-290, SP-1000”, “Polyflow No. 50E, No. 300 (acrylic copolymer)”, “Disparon KS-860, 873SN, 874 (polymer dispersing agent), # 2150 (manufactured by Enomoto Kasei Co., Ltd.) Aliphatic polyvalent carboxylic acid), # 7004 (polyether ester type) ” That.

  Further, “Demol RN, N (Naphthalenesulfonic acid formalin condensate sodium salt), MS, C, SN-B (aromatic sulfonic acid formalin condensate sodium salt), EP”, “Homogenol L-18 (poly) Carboxylic acid type polymer), “Emulgen 920, 930, 931, 935, 950, 985 (polyoxyethylene nonyl phenyl ether)”, “Acetamine 24 (coconut amine acetate), 86 (stearyl amine acetate)”, manufactured by Lubrizol “Solspers 5000 (phthalocyanine ammonium salt type), 13940 (polyester amine type), 17000 (fatty acid amine type), 24000”, “Nikkor T106 (polyoxyethylene sorbitan monooleate), MYS-IEX (polyoxy) manufactured by Nikko Chemical Co., Ltd. Ciethylene monostearate), Hexagline 4-0 (hexaglyceryl tetraoleate) ”,“ Ajisper PB821, PB822 (basic dispersant) ”manufactured by Ajinomoto Fine Techno Co., etc. The dispersant is preferably contained in the ink in an amount of 0.1 to 10% by weight.

  The ink composition of the present invention can use various additives such as a plasticizer, a surface conditioner, an ultraviolet light inhibitor, a light stabilizer, an antioxidant, and a hydrolysis inhibitor.

  Examples of the printing medium of the present invention include a polyvinyl chloride resin sheet, a polyolefin-based sheet, glass, metal and the like, and a polyvinyl chloride resin sheet is particularly preferable.

  Examples of the printing method of the ink composition of the present invention include gravure printing, flexographic printing, silk screen printing, ink jet printing, and the like, and the ink jet printing method is particularly preferable.

  The ink composition of the present invention is prepared by first dispersing a pigment in a single or mixed solvent with a resin or a dispersant using a paint shaker, sand mill, roll mill, medialess disperser, etc. It is manufactured by diluting with the solvent of the invention.

  EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight”.

[Production Example 1]
First, Pigment Dispersion A was prepared with the following composition. This dispersion was prepared by adding a pigment and a dispersant into an organic solvent, stirring until uniform with a high speed mixer or the like, and dispersing the obtained mill base with a horizontal sand mill for about 1 hour.
・ ELFTEX 415 (carbon black manufactured by Cabot) 35.00 parts ・ Azisper PB821 (pigment dispersant manufactured by Ajinomoto Fine Techno Co.) 12.50 parts ・ Diethylene glycol diethyl ether 52.50 parts

[Production Example 2]
Further, a pigment dispersion B was prepared in the same manner as in Production Example 1 with the following composition.
・ YELLOW PIGMENT E4GN (Nickel complex azo pigment manufactured by LANXESS) 30.00 parts ・ Solspers 17000 (pigment dispersant manufactured by Lubrizol) 16.50 parts ・ Diethylene glycol ethyl methyl ether 53.50 parts

[Production Example 3]
Further, a pigment dispersion C was prepared in the same manner as in Production Example 1 with the following formulation.
-Chromophthal Pink PT (Cinacridone pigment manufactured by Ciba Specialty Chemicals) 32.0 parts-Solsperz 24000 (pigment dispersant manufactured by Lubrizol Corporation) 12.8 parts-Ethylene glycol monobutyl ether acetate 55.2 parts

[Production Example 4]
Further, a pigment dispersion D was prepared in the same manner as in Production Example 1 with the following formulation.
LIONOL BLUE FG-7400G (phthalocyanine pigment manufactured by Toyo Ink Mfg. Co.) 35.00 parts Azisper PB821 (pigment dispersant manufactured by Ajinomoto Fine Techno Co.) 12.50 parts diethylene glycol diethyl ether 52.50 parts

[Example 1]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion A 11.40 parts Vinyl resin H40 / 43 (wacker vinyl chloride resin) 4.50 parts Citric acid 0.50 parts Diethylene glycol diethyl ether 83.60 parts
[Example 2]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion A 11.40 parts Vinyl resin H40 / 43 (vinyl acetate resin manufactured by Wacker) 4.50 parts Propylene glycol diacetate 5.00 parts Citric acid 0.50 parts Diethylene glycol diethyl ether 78. 60 copies
[Example 3]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion A 11.40 parts Vinyl resin H40 / 43 (wacker vinyl chloride resin) 4.50 parts butyl lactate 5.00 parts citric acid 0.50 parts diethylene glycol diethyl ether 78.60 parts

[Example 4]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
-Pigment dispersion C 12.50 parts-Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts-Diethylene glycol ethyl methyl ether 5.00 parts-Citric acid 0.50 parts-Ethylene glycol monobutyl ether acetate 77 .50 parts
[Example 5]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
-Pigment dispersion A 11.40 parts-Vinyl resin sorbine CL (vinyl acetate resin made by Nissin Chemical Industry Co., Ltd.) 4.50 parts-3-methyloxazolidinone 5.00 parts-Citric acid 0.50 parts-Diethylene glycol diethyl ether 78.60 parts
[Example 6]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion B 16.00 parts Vinyl resin sorbine CNL (Nisshin Chemical Industries vinyl chloride resin) 4.50 parts 3-ethyloxazolidinone 5.00 parts Fumaric acid 0.50 parts Diethylene glycol ethyl methyl 74.00 parts of ether

[Example 7]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion C 12.50 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts Dimethyl sulfoxide 5.00 parts Maleic anhydride 0.50 parts Ethylene glycol monobutyl ether acetate 77. 50 copies
[Example 8]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 1-methyl-2-pyrrolidone 5.00 parts Phthalic acid 0.50 parts Diethylene glycol diethyl ether 78.60 parts
[Example 9]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts Gamma-butyrolactone 5.00 parts Succinic acid 0.50 parts Diethylene glycol diethyl ether 78.60 parts

[Example 10]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (a vinyl acetate resin made by Dow Chemicals) 4.50 parts ε-caprolactone 5.00 parts Succinic anhydride 0.50 parts Diethylene glycol diethyl ether 78.60 Part
[Example 11]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Tetraethylene glycol dimethyl ether 10.00 parts Citric acid 10 parts ・ Diethylene glycol diethyl ether 68.60 parts
[Example 12]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Tetraethylene glycol dimethyl ether 10.00 parts Citric acid 01 parts ・ Diethylene glycol diethyl ether 69.09 parts
[Example 13]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (Dow Chemicals vinyl acetate resin) 4.50 parts 3-methyloxazolidinone 5.00 parts Tetraethylene glycol dimethyl ether 10.00 parts Citric acid 50 parts ・ Diethylene glycol diethyl ether 66.60 parts

[Example 14]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Tetraethylene glycol dimethyl ether 10.00 parts Citric acid 4. 50 parts ・ Diethylene glycol diethyl ether 64.60 parts
[Example 15]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Tetraethylene glycol dimethyl ether 10.00 parts Citric acid 6. 00 parts ・ Diethylene glycol diethyl ether 63.10 parts

[Comparative Example 1]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.

-Pigment dispersion A 11.40 parts-Vinyl resin sorbine CL (vinyl acetate resin manufactured by Nissin Chemical Industry Co., Ltd.) 4.50 parts-3-methyloxazolidinone 5.00 parts-Diethylene glycol diethyl ether 79.10 parts
[Comparative Example 2]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion B 16.00 parts Vinyl resin sorbine CNL (Nisshin Chemical Industries vinyl chloride resin) 4.50 parts 3-Ethyloxazolidinone 5.00 parts Diethylene glycol ethyl methyl ether 74.50 parts
[Comparative Example 3]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.

-Pigment dispersion C 12.50 parts-Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts-Dimethyl sulfoxide 5.00 parts-Ethylene glycol monobutyl ether acetate 78.00 parts
[Comparative Example 4]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts diethylene glycol diethyl ether 79.10 parts
[Comparative Example 5]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Acetic acid 1.00 parts Diethylene glycol diethyl ether 78.10 parts
[Comparative Example 6]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Adeka Stub AC-285 (Adeka Ba-Zn liquid one Pack type stabilizer)
0.50 parts ・ Diethylene glycol diethyl ether 78.60 parts

[Comparative Example 7]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment Dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Adeka Stub SC-320 (ADEKA company Ca-Zn liquid stable Agent)
0.50 parts ・ Diethylene glycol diethyl ether 78.60 parts
[Comparative Example 8]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.

-Pigment dispersion D 11.40 parts-Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts-3-methyloxazolidinone 5.00 parts-Adekastab 466 (dialkyl tin mercaptide stabilizer made by ADEKA)
0.50 parts ・ Diethylene glycol diethyl ether 78.60 parts
[Comparative Example 9]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.

Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Adekaiser O-130P (epoxidized soybean oil made by ADEKA) 0.50 parts ・ Diethylene glycol diethyl ether 78.60 parts

[Comparative Example 10]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Adekastab PFR (organic phosphate ester compound made by ADEKA) 0 .50 parts ・ Diethylene glycol diethyl ether 78.60 parts
[Comparative Example 11]
The pigment dispersion was converted into an ink with the following formulation to obtain an ink composition.
Pigment dispersion D 11.40 parts Vinyl resin VYHD (vinyl chloride resin made by Dow Chemicals) 4.50 parts 3-methyloxazolidinone 5.00 parts Adekaiser O-130P (epoxidized soybean oil made by ADEKA) 0.50 parts-ADK STAB AC-285 (Adeka Ba-Zn liquid one-pack stabilizer)
0.50 parts ・ Diethylene glycol diethyl ether 78.10 parts

  About each solvent pigment ink composition of said Examples 1-15 and Comparative Examples 1-11, when viscosity stability, the chlorine content change in an ink composition with time, and the ion in an ink composition were phase-shifted to water Tests were carried out for the pH value change of the aqueous phase, the chemical resistance of the ink coating, the yellowing of the resin varnish, and the printing stability.

Each test method and evaluation method are shown in detail below.
<Viscosity stability>
The viscosity of the ink compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 11 was evaluated using an E-type viscometer (manufactured by Nikkiso) before and after aging acceleration at 70 ° C. for 8 weeks. A change rate of less than 2% was evaluated as ◯, a change rate of 2% or more and less than 5% was evaluated as Δ, and a change rate of 5% or more was evaluated as ×.

<Change in chlorine content in ink composition over time>
In order to measure the amount of chlorine in the ink composition, 10 parts of the solvent pigment ink composition and 10 5 mmφ glass beads are charged into a sample bottle. After 90 parts of purified water was added while applying ultrasonic waves, the handshake was performed 60 times and allowed to stand for 20 minutes or longer, and then the lower aqueous phase was filtered using a membrane filter to obtain a sample for measuring the amount of chlorine. It was. The amount of chlorine in this sample was measured using a Dionex ion chromatograph DX-500.
As the determination method, the ink compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 11 were evaluated as ◯ when the amount of increase in chlorine was less than 30 ppm before and after aging promotion at 70 ° C. for 8 weeks. Of 30 ppm or more and less than 50 ppm was evaluated as Δ, and when the increase was 50 ppm or more was evaluated as ×.

<pH measurement>
In order to invert the ions in the ink composition to water, 15 parts of the solvent pigment ink composition was dropped little by little into 85 parts of purified water being stirred by a magnetic stirrer, stirred for 30 minutes, and then allowed to stand for 20 minutes or more. Filtration was repeated using a membrane filter until the lower aqueous phase became transparent to obtain a filtrate. The pH of this filtrate was measured using a pH meter: F-52S manufactured by HORIBA, electrode: model 6377-10D.
As the determination method, the ink compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 11 had a pH change rate of less than 10% before and after the aging promotion at 70 ° C. for 8 weeks, and the change rate. Of 10% or more and less than 20% was evaluated as Δ, and the rate of change was evaluated as 20% or more.

<Chemical resistance of ink coating film>
The ink compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 11 were printed on an untreated polyvinyl chloride resin sheet with Colorpainter 64S (manufactured by Seiko I Infotech, large-format inkjet printer). The printing surface was evaluated for chemical resistance of the ink coating film with a rubbing tester (Model AB301, manufactured by Tester Sangyo). As evaluation conditions, a test cloth piece (gold width 3) was wetted with ethanol, subjected to a load of 200 g, 10 reciprocations, and the coated surface was not peeled off at all, ◯, a part of the color fell △, What peeled off and the base material was visible was evaluated as x.

<Printing stability>
After the aging of the ink compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 11 at 70 ° C. for 8 weeks, Colorpainter 64S (manufactured by Seiko I Infotech Co., Ltd., large-format ink jet printer) in a 25 ° C. environment. Then, the surface is continuously printed on an untreated polyvinyl chloride resin sheet, and the occurrence frequency of missing dots, flying bends or ink splashes is evaluated, and the missing dots, flying bends or scattered inks are generated in a 50-hour test. Or less than 10 times, missing dots in 50-hour continuous test, occurrence of flying bend or ink splatter or more than 10 times, less than 20 times, missing dots in 50-hour continuous test, The case where the occurrence of the flight bending or the ink scattering was 20 times or more was evaluated as x.

<Yellow condition of resin varnish>
From the ink composition formulations obtained in Examples 1 to 15 and Comparative Examples 1 to 11, the degree of yellowing of the varnish was evaluated before and after the aging of the resin varnish from which the pigment was removed at 70 ° C. for 8 weeks. As an evaluation method, before and after accelerating the aging of the resin varnish at 70 ° C. for 8 weeks, the surface was coated with a wet 12 μm wire bar on an untreated polyvinyl chloride resin sheet, dried, and then the L ^* , a ^* , The b ^* value was measured using an X-Rite 500 series (manufactured by X-Rite Co., Ltd.), and it was evaluated by checking whether or not the b ^* value had shifted to the plus side before and after acceleration over time. Before and after the passage of time, the b ^* value change width was less than 0.2, the b ^* value change width was 0.2 or more and less than 0.5, and the b ^* value change width was 0. What was 5 or more was evaluated as x. The blank section is currently being tested.

  As apparent from the results shown in Table 1 below, the vinyl chloride resin can be removed by adding a polyvalent carboxylic acid or its anhydride to the ink composition using a vinyl chloride resin as the binder resin. Since the hydrochloric acid reaction could be suppressed, an ink composition excellent in storage stability could be obtained.

  Citric acid, fumaric acid, and maleic anhydride are excellent as the types of polyvalent carboxylic acids or anhydrides to be added, and citric acid is the most popular because of its solubility in solvents, safety, and the yellowness of the coating film. I found it excellent.

  It was found that the optimum addition amount exists because the chemical resistance of the ink coating film deteriorates when the addition amount is too large.

  In addition, although polyvalent carboxylic acid or its anhydride is not added, monovalent carboxylic acid or a conventionally used vinyl chloride resin stabilizer is added, dehydrochlorination reaction cannot be suppressed, As a result, an increase in viscosity was observed.

Claims (6)

An ink-jet ink composition comprising a pigment, a vinyl chloride resin , and an organic solvent having a boiling point of 140 ° C. or higher at 1 atm , containing citric acid or an anhydride thereof. An inkjet ink composition comprising at least a pigment, a vinyl chloride resin, and at least one organic solvent selected from the solvents represented by the general formulas (1) to (4). An ink-jet ink composition comprising a product.
R ₁ CO (OR ₂ ) _Z OR ₃ (1) R ₄ CO (OR ₅ ) _Z OCOR ₆ (2)
(Poly) ethylene glycol diether (3)
R ₁₀ COOR ₁₁ (4)
(Wherein R _{2 and} R ₅ are each independently an ethylene group or a propylene group, R ₁ , R ₃ ,
R ₄ and R ₆ each independently represent an alkyl group having 1 to 4 carbon atoms, R ₁₀ represents a 1 -hydroxyethyl group, R ₁₁ represents an alkyl group having 1 to 8 carbon atoms, and Z represents an integer of 1 to 3. ) An ink- jet ink composition comprising a pigment, a vinyl chloride resin, and a nitrogen-containing, sulfur-containing, or lactone-based solvent as a part of an organic solvent having a boiling point of 140 ° C. or higher at 1 atm. An ink-jet ink composition comprising an anhydride. 3. The ink-jet ink composition according to claim 1, further comprising a nitrogen-containing, sulfur-containing or lactone solvent as part of the organic solvent. Furthermore, content of polyhydric carboxylic acid or its anhydride contained in an ink composition is less than 5 weight% in ink, The inkjet ink composition in any one of the Claims 1 thru | or 4 characterized by the above-mentioned. Furthermore inkjet ink composition of claims 1 to 5, wherein any one, characterized in that it contains a dispersing agent in the ink composition.