Liquid printing inks, printed matter, and packaging materials

Abstract

To provide a liquid print ink having all of excellent adhesion to a substrate, scratch resistance, heat resistance, oil resistance, alcohol resistance, polyvinyl chloride blocking resistance, and gloss.SOLUTION: The present invention provides a liquid print ink containing a white pigment, a binder resin, and at least one compound selected from phosphorus acid-modified compounds represented by general formulae (1)-(4). In the general formula (1), R1 denotes an epoxy resin or a modified epoxy resin with a number average molecular weight of 500-3000.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a liquid printing ink that can be used as a gravure ink or a flexographic ink for flexible packaging. [Background technology]

[0002] Gravure ink and flexographic ink are widely used to impart beauty and functionality to printed materials such as soft packaging films and paper. When gravure- or flexographically printed printed materials are used as packaging materials, particularly soft packaging materials for food and sanitary products, the product packaging is printed with a front-side print, which prints the design only on the outside of the packaging material, without printing on the back side, which is the side of the packaging material that comes into contact with the contents, in order to prevent contact with the contents. In addition, reverse-side print is used on transparent films for applications such as beverage labels, integrated packaging, cup noodle overlaps, and food packaging films. These liquid printing inks have the risk that the ink film printed on a film or paper substrate may be rubbed off by direct external forces or come into contact with other substances. Therefore, in addition to good adhesion to the film or paper substrate, it is desirable for the ink to have the heat resistance, oil resistance, and alcohol resistance required particularly for surface printing, as well as polyvinyl chloride (PVC) blocking resistance to take into consideration contact with tablecloths, and a good glossiness of the finished print from the standpoint of the design of the packaging material using the printed matter.

[0003] There have been inventions of gravure ink compositions using urethane resins and cellulose derivatives (e.g., Patent Documents 1 and 2), surface printing gravure ink compositions containing polyurethane resins, vinyl chloride-vinyl acetate copolymers, rosin, and chelates (e.g., Patent Documents 3 and 4), and surface printing gravure ink compositions using ester resins and ester dispersants (e.g., Patent Document 5), but none of these can be said to have sufficient adhesion to the substrate, various resistances, and gloss. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-246822 A [Patent Document 2] JP 2002-294128 A [Patent Document 3] JP 2012-012597 A [Patent Document 4] JP 2013-256551 A [Patent Document 5] JP 2017-039896 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a liquid printing ink which combines good adhesion to a substrate, scratch resistance, heat resistance, oil resistance, alcohol resistance, PVC blocking resistance, and gloss. [Means for solving the problem]

[0006] As a result of extensive research into solving the above-mentioned problems, the inventors have found that in a liquid printing ink, containing a white pigment, a binder resin, and a phosphoric acid-modified compound represented by a specific general formula is effective in solving the problems.

[0007] That is, the present invention provides a liquid printing ink comprising a white pigment, a binder resin, and one or more compounds selected from the phosphoric acid modified compounds represented by general formulas (1) to (4).

[0008] [ka] (1)

[0009] [ka] (2)

[0010] [ka] (3)

[0011] [ka] (4) In general formulas (1) to (4), R 1 , R 2 , R 3 each independently represents an epoxy resin or modified epoxy resin having a number average molecular weight of 500 to 3000, R 4 , R 7 , R 8 each independently represents an alkylene chain having 2 or less carbon atoms; R 5 , R 6 , R 9 each independently represents an epoxy group, a methacryloyl group, or an acryloyl group.

[0012] The present invention also provides a liquid printing ink containing, as the binder resin, a cellulose-based resin, a urethane-based resin, a rosin resin, or a chlorinated polyolefin resin.

[0013] The present invention also provides a liquid printing ink which further comprises a titanium-based chelating crosslinking agent.

[0014] The present invention also provides a liquid printing ink for printing on plastic films or paper.

[0015] The present invention also provides a printed matter produced using the liquid printing ink.

[0016] The present invention also provides a packaging material which uses the liquid printing ink. Effect of the Invention

[0017] According to the present invention, it is possible to obtain a liquid printing ink which combines good adhesion to a substrate, scratch resistance, heat resistance, oil resistance, alcohol resistance, PVC blocking resistance, and gloss. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (Definition of words) In the present invention, the liquid printing ink refers to a liquid ink such as gravure ink or flexographic ink that is applied to a printing method using a printing plate, and is preferably gravure ink or flexographic ink. The liquid printing ink of the present invention does not contain an active energy curable component, i.e., is an active energy ray non-reactive liquid ink. In the following description, all "ink" refers to "printing ink." Furthermore, all "parts" refer to "parts by mass," "total amount of ink" refers to the total amount of ink including all volatile components such as organic solvents, and "total amount of ink solids" refers to the total amount of only non-volatile components, excluding volatile components.

[0019] (binder resin) The binder resin used in the present invention is not particularly limited as long as it is a general-purpose binder resin in gravure ink or flexo ink, and examples thereof include cellulose-based resins such as cellulose acetate propionate (CAP) and cellulose acetate butyronate (CAB), urethane-based resins, rosin-based resins, chlorinated polyolefin resins, nitrocellulose, polyamide-based resins, acrylic resins, polyvinyl-based resins such as vinyl chloride-vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, and polyvinyl chloride resins, polyester resins, alkyd resins, ketone resins, cyclized rubber, chlorinated rubber, butyral, and petroleum resins. Among them, it is preferable to use a cellulose-based resin in combination with a polyurethane resin, and more preferably to use a chlorinated polyolefin resin or a rosin-based resin in combination.

[0020] (Cellulose-based resin) Examples of cellulose resins include cellulose acetate propionate, cellulose acetate butyrate and other cellulose ester resins, nitrocellulose (also called soluble cellulose), hydroxyalkyl cellulose, and carboxyalkyl cellulose. The cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, and a hexyl group, and the alkyl group may further have a substituent. Of the above, nitrocellulose is preferred as the cellulose-based resin. The molecular weight is preferably 5,000 to 200,000 in weight average molecular weight, more preferably 10,000 to 50,000. Also, the glass transition temperature is preferably 120°C to 180°C. In particular, when used in combination with polyurethane resin, it is expected that blocking resistance and other physical properties of the ink film will be improved. Nitrocellulose (nitrocellulose) is preferably obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydrous glucopyranose group in the natural cellulose with nitric acid groups to produce a nitric acid ester.

[0021] The use of nitrocellulose (nitrocellulose) provides high dispersibility in white pigments, and is therefore suitable for use as a coating agent for surface printing, which can improve the strength of the printing ink coating. The nitrocellulose (nitrocellulose) preferably has a nitrogen content of 10 to 13% by mass and an average degree of polymerization of 30 to 500, and more preferably has a nitrogen content of 10 to 13% by mass and an average degree of polymerization of 45 to 290.

[0022] The amount of nitrocellulose (soluble nitrocellulose) added is preferably 1 to 20% by mass, and more preferably 5 to 10% by mass, based on the total amount of ink solids.

[0023] (Polyurethane resin) The polyurethane resin is not particularly limited as long as it is a polyurethane resin obtained by reacting a polyol with a polyisocyanate. For example, various known polyols generally used in the production of polyurethane resins can be used as the polyol, and one or more of them may be used in combination. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5 pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropionate, etc. Saturated or unsaturated low molecular weight polyols (1), such as ethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, and pentaerythritol; these low molecular weight polyols (1) and sebacic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, and trimellitic acid. polyester polyols (2) obtained by dehydration condensation or polymerization of polyvalent carboxylic acids such as pyromellitic acid or their anhydrides; polyester polyols (3) obtained by ring-opening polymerization of cyclic ester compounds, such as lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone); polycarbonate polyols (4) obtained by reacting the low molecular weight polyols (1) or the like with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, or the like; polybutadiene glycols (5); glycols (6) obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols (7) obtained by copolymerizing one or more hydroxyethyl groups, hydroxypropyl acrylate, hydroxybutyl acrylate, or the like, or the corresponding methacrylic acid derivatives, in one molecule, with, for example, acrylic acid, methacrylic acid, or an ester thereof.

[0024] Examples of the polyisocyanate include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane resins. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, Aromatic polyisocyanates such as zene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and diphenylmethane-2,4-diisocyanate;Aliphatic or alicyclic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatemethyl)cyclohexane, 1,4-di(isocyanatemethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, these diisocyanate compounds can be used alone or in combination of two or more kinds.

[0025] A chain extender can also be used. Examples of the chain extender include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and the like, as well as amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. These chain extenders can be used alone or in combination of two or more.

[0026] In addition, a monovalent active hydrogen compound can be used as a terminal blocking agent for the purpose of stopping the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine, and alcohols such as ethanol and isopropyl alcohol. Furthermore, when it is particularly desired to introduce a carboxyl group into the polyurethane resin, amino acids such as glycine and L-alanine can be used as a reaction stopping agent. These terminal blocking agents can be used alone or in combination of two or more. The weight average molecular weight of the polyurethane resin is preferably in the range of 10,000 to 100,000, and more preferably 15,000 to 80,000. The amount of polyurethane resin added is preferably 1 to 30% by mass, and more preferably 5 to 25% by mass, based on the total amount of ink solids.

[0027] (rosin resin) The rosin-based resin used in the present invention can be any rosin or rosin derivative that is widely used for printing inks, without any particular limitation. Specifically, the rosin or rosin derivative is rosins or carboxyl group-containing derivatives thereof. Rosins include gum rosin, wood rosin, tall oil rosin, disproportionated rosin, hydrogenated rosin, and polymers thereof. Rosin derivatives include carboxyl group-containing derivatives such as rosin derivatives to which unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, and crotonic acid have been added. The amount of the rosin resin added is preferably 1 to 20% by mass, and more preferably 5 to 10% by mass, based on the total amount of ink solids.

[0028] In the present invention, it is preferable to use a rosin-modified maleic acid resin, which is a maleic acid derivative of rosin, or a rosin-modified fumaric acid resin, which is a fumaric acid derivative of rosin, in that they contribute to the stability over time of the liquid printing ink. The rosin-modified maleic acid resin or rosin-modified fumaric acid resin used in the present invention is not particularly limited, and any known rosin-modified maleic acid resin or rosin-modified fumaric acid resin can be used. The rosin-modified maleic acid resin or rosin-modified fumaric acid resin preferably has an acid value of 25 mgKOH / g or more and 320 mgKOH / g or less, and particularly preferably has an acid value of 100 mgKOH / g or more and 320 mgKOH / g or less.

[0029] Examples of commercially available rosin-based resins include Marquid No. 1, 2, 5, 6, 8, 31, 32, 33, 34, and 3002 manufactured by Arakawa Chemical Industries, Ltd., and Harimamac R-80, T-80, R-100, M-453, M-130A, 135GN, 145P, R-120AH, Haritac 4851, 4821, 4740, and 28JA manufactured by Harima Chemical Industries, Ltd.

[0030] (Chlorinated polyolefin resin) The chlorinated polyolefin resin used in the present invention is not particularly limited as long as it is a polyolefin resin in which at least a part of hydrogen atoms is replaced by chlorine atoms. The weight average molecular weight of the chlorinated polyolefin is preferably 5,000 to 100,000, more preferably 5,000 to 70,000, and even more preferably 7,000 to 50,000. In addition, the chlorine content of the chlorinated polyolefin resin is preferably 25 to 45% by mass in order to improve adhesion to the substrate. In addition, from the viewpoint of solubility in organic solvents, the chlorine content is more preferably 26 to 43% by mass. Here, the chlorine content refers to the mass % of chlorine atoms contained in 100% by mass of the chlorinated polyolefin resin. In addition, from the viewpoint of balance with blocking resistance, the chlorinated polyolefin resin is contained in the ink solid content in an amount of 1 to 30% by mass, preferably 2 to 20% by mass.

[0031] Chlorinated polyolefin resins have flexible alkyl groups as branched structures, so they are flexible even at low temperatures and contribute to improving adhesion to substrates. The structure of the polyolefin resin in the chlorinated polyolefin resin is not particularly limited. For example, resins containing homopolymers or copolymers of α-olefin-based unsaturated hydrocarbons such as polypropylene, poly-1-butene, and poly-4-methyl-1-pentene are preferred. Among these, chlorinated polypropylene resins containing a polypropylene structure (i.e., a chlorinated polypropylene structure) are particularly preferred.

[0032] (Polyamide resin) Furthermore, in the liquid printing ink of the present invention, a polyamide resin may be used as the binder resin. The polyamide resin is, for example, a thermoplastic polyamide soluble in an organic solvent that can be obtained by polycondensation of a polybasic acid and a polyamine. In particular, a polyamide resin containing a reaction product of an acid component containing a polymerized fatty acid and / or a dimer acid with an aliphatic and / or aromatic polyamine is preferable, and further, a polyamide resin containing a portion of primary and secondary monoamines is preferable. Examples of polybasic acids used as raw materials for polyamide resins include, but are not limited to, adipic acid, sebacic acid, azelaic acid, phthalic anhydride, isophthalic acid, suberic acid, glutaric acid, fumaric acid, pimelic acid, oxalic acid, malonic acid, succinic acid, maleic acid, terephthalic acid, 1,4-cyclohexyldicarboxylic acid, trimellitic acid, dimer acid, hydrogenated dimer acid, and polymerized fatty acid. Among these, polyamide resins containing a structure derived from dimer acid or polymerized fatty acid as the main component (50% by mass or more in the polyamide resin) are preferred. Here, polymerized fatty acid is obtained by cyclization reaction of unsaturated fatty acid, and includes monobasic fatty acid, dimerized polymerized fatty acid (dimer acid), trimerized polymerized fatty acid, and the like. Fatty acids constituting dimer acid or polymerized fatty acid include those derived from natural oils such as soybean oil, palm oil, and rice bran oil, and those obtained from oleic acid and linoleic acid are preferred. The polybasic acid may be used in combination with a monocarboxylic acid, such as acetic acid, propionic acid, lauric acid, palmitic acid, benzoic acid, or cyclohexane carboxylic acid.

[0033] Examples of the polyamine include polyamines, primary or secondary monoamines, etc. Examples of the polyamines used in the polyamide resin include aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, and methylaminopropylamine, and aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and examples of the alicyclic polyamines include cyclohexylenediamine and isophoronediamine. Examples of the aromatic aliphatic polyamines include xylylenediamine, and examples of the aromatic polyamines include phenylenediamine and diaminodiphenylmethane. Examples of the primary and secondary monoamines include n-butylamine, octylamine, diethylamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine. The amount of polyamide resin added is 0.1 to 5.0% by mass, preferably 0.5 to 2.0% by mass, based on the ink solid content.

[0034] (Acrylic resin) Furthermore, in the liquid printing ink of the present invention, an acrylic resin may be used as the binder resin. The acrylic resin is not particularly limited as long as it is a copolymer of a polymerizable monomer mainly composed of (meth)acrylic acid ester. Examples of the polymerizable monomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, iso-octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, iso-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate. The polymerization method is not particularly limited, and those obtained by known bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. can be used. The weight average molecular weight of the acrylic resin is preferably in the range of 5,000 to 200,000, and more preferably in the range of 10,000 to 100,000. The amount of the acrylic resin added is 0.1 to 5.0% by mass, preferably 0.5 to 2.0% by mass, based on the ink solid content.

[0035] (polyester resin) Furthermore, in the liquid printing ink of the present invention, a polyester resin may be used as the binder resin. The polyester resin is not particularly limited as long as it is a polyester resin obtained by reacting an alcohol with a carboxylic acid using a known esterification polymerization reaction. Examples of alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,2-pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaerythritol, 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, spiroglycol, and isosorbide. These may be used alone or in combination of two or more. Among these, polyfunctional alcohols are preferred. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oleic acid, linoleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, and 1,4-cyclohexanedicarboxylic acid. These may be used alone or in combination of two or more. Among these, polyfunctional carboxylic acids are preferred. The weight average molecular weight of the polyester resin is preferably 500 to 6000, and more preferably 1400 to 5500. The amount of polyester resin added is 0.1 to 5.0% by mass, preferably 0.5 to 2.0% by mass, based on the ink solid content.

[0036] (Vinyl resin) Furthermore, in the liquid printing ink of the present invention, a vinyl resin may be used as the binder resin. The vinyl resin used in the present invention may be a copolymer of a compound having a vinyl group, and representative copolymers include copolymers using vinyl chloride or vinyl acetate. Examples of vinyl chloride resins include polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinyl chloride copolymer, Examples of vinyl chloride resins include vinyl chloride-vinyl acetate terpolymers, vinyl chloride-maleic acid ester copolymers, vinyl chloride-methacrylic acid ester copolymers, vinyl chloride-acrylonitrile copolymers, vinyl chloride-various vinyl ether copolymers, and blends thereof, or other chlorine-free synthetic resins, such as acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, ethylene-vinyl acetate copolymers, ethylene-ethyl (meth)acrylate copolymers, blends with polyesters, block copolymers, graft copolymers, etc. These vinyl chloride resins may be a mixture of two or more kinds, or may be a mixture with other synthetic resins.

[0037] The vinyl acetate resin is a copolymer of vinyl acetate monomer alone or a copolymer of vinyl acetate monomer and a polymerizable unsaturated monomer. Examples of the unsaturated monomer include long-chain (meth)acrylic monomers such as alkyl (meth)acrylate monomers, such as n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate; hydroxyl group-containing (meth)acrylic monomers, such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 1,4-butanediol mono(meth)acrylate, and (poly)ethylene glycol mono(meth)acrylate; carboxyl group-containing monomers, such as (meth)acrylic acid, maleic acid, and maleic anhydride; vinyl monomers, such as styrene, acrylonitrile, and vinyl chloride; and ethylene. These may be used alone or in combination of two or more.

[0038] The molecular weight of the vinyl resin is preferably 5,000 to 100,000, more preferably 10,000 to 70,000, in terms of weight average molecular weight.

[0039] Among these, vinyl chloride resins which are homopolymers of the vinyl chloride monomer, vinyl acetate resins which are homopolymers of vinyl acetate monomer, and vinyl chloride-vinyl acetate copolymer resins obtained by copolymerizing the vinyl chloride monomer, the vinyl acetate monomer, and, if necessary, vinyl alcohol or the like, are preferred. The vinyl chloride-vinyl acetate copolymer resin is not particularly limited as long as it is a copolymer of vinyl chloride and vinyl acetate. From the viewpoint of solubility in organic solvents, it is also preferable to have a hydroxyl group derived from a vinyl alcohol structure. The hydroxyl value is preferably 20 to 200 mgKOH / g. The glass transition temperature is preferably 50°C to 90°C. In the 100% by mass solid content of the vinyl chloride-vinyl acetate copolymer resin, the vinyl acetate monomer-derived structure is preferably 1 to 30% by mass, and the vinyl chloride monomer-derived structure is preferably 70 to 95% by mass. In this case, the solubility in organic solvents is improved, and further, the adhesion to the substrate, the coating properties, the scratch resistance, etc. are improved. The amount of vinyl resin added is 0.1 to 5.0% by mass, preferably 0.5 to 2.0% by mass, based on the ink solid content.

[0040] (hardening agent) If necessary, a hardener may be used in combination with the binder resin. As the hardener, any hardener generally used in organic solvent-based gravure inks may be used, but the most commonly used hardeners are isocyanate-based hardeners. From the viewpoint of curing efficiency, the amount of the isocyanate compound added is preferably in the range of 0.3% by mass to 10.0% by mass, and more preferably 1.0% by mass to 7.0% by mass, based on the solid content of the liquid printing ink. The total amount of the binder resin is preferably in the range of 0.15 to 50% by mass, and most preferably in the range of 1 to 40% by mass, based on the ink solid content.

[0041] (Phosphate-modified compounds represented by general formulas (1) to (4)) The present invention is characterized in that it contains at least one compound selected from the group consisting of phosphoric acid modified compounds represented by general formulas (1) to (4).

[0042] [ka] (1)

[0043] [ka] (2)

[0044] [ka] (3)

[0045] [ka] (4)

[0046] In the general formulas (1) to (4) above, R 1 , R 2 , R 3 each independently represents an epoxy resin or modified epoxy resin having a number average molecular weight of 500 to 3000, R 4 , R 7 , R 8 each independently represents an alkylene chain having 2 or less carbon atoms; R 5 , R 6 , R 9 each independently represents an epoxy group, a methacryloyl group, or an acryloyl group.

[0047] The compound represented by the general formula (1) or the compound represented by the general formula (2) is a compound obtained by modifying an epoxy resin, and R 1 , R 2 , R 3 each independently represents an epoxy resin or modified epoxy resin having a number average molecular weight of 500 to 3000. The compound represented by general formula (1) or the compound represented by general formula (2) can be modified with methacrylic acid or acrylic acid to adjust the acid value in order to improve compatibility with the above-mentioned binder resin, organic solvent, etc. Examples of commercially available phosphate-modified compounds that meet the above conditions include Watersol EF5460 (DIC Corporation) and Epicron P-415 (DIC Corporation).

[0048] In addition, R in the compound represented by the above-mentioned general formula (3) or the compound represented by the general formula (4) 4 , R 7 , R 8are each independently selected from the viewpoint of compatibility with the above-mentioned binder resin, organic solvent, etc., to be an alkylene chain having 2 or less carbon atoms. In addition, R 5 , R 6 , R 9 each independently represents an epoxy group, a methacryloyl group, or an acryloyl group. By using such reactive functional groups, the oil resistance can be further improved.

[0049] The phosphoric acid modified compound represented by the general formulas (1) to (4) is contained in the ink solids in an amount of preferably 1 to 25% by mass, more preferably 2 to 20% by mass, and even more preferably 4 to 15% by mass.

[0050] (wax) It is also preferred to add wax to the liquid printing ink of the present invention. As the wax, it is preferred to use polyolefin wax or fatty acid amide wax, which are well known in the field of liquid printing inks. The amount of wax to be added is not particularly limited and may be within a known range, but the total amount of wax is usually contained within the range of 0.1 to 20 mass% based on the total solid content of the ink.

[0051] Examples of polyolefin waxes include oxidized polyethylene wax, oxidized polypropylene wax, etc. The polyolefin wax is preferably contained in an amount of 0.05 to 1 mass % relative to the total solid content of the ink, and more preferably 0.1 to 0.5 mass %.

[0052] Examples of fatty acid amide waxes include saturated fatty acid amides such as stearic acid amide and palmitic acid amide, unsaturated fatty acid amides such as erucic acid amide, substituted amides, and aromatic amides. Among them, the combined use of saturated fatty acid amide and unsaturated fatty acid amide is more preferable because it further improves adhesion and scratch resistance, and specifically, the combined use of palmitic acid amide and erucic acid amide can be mentioned. The fatty acid amide wax is preferably contained in an amount of 0.05 to 1 mass % based on the total solid content of the ink, and more preferably contained in an amount of 0.1 to 0.5 mass %.

[0053] (Chelate-based crosslinking agent) The chelate-based crosslinking agent used in the liquid printing ink of the present invention is preferably a chelate-type metal organic compound intended to improve cohesive strength. As the metal chelate-based crosslinking agent, a titanium-based chelate crosslinking agent, a zirconium-based chelate crosslinking agent, or an aluminum-based chelate crosslinking agent can be used. Among these, a titanium-based chelate crosslinking agent is preferred. If a chelate-type metal organic compound is used, the crosslinking reaction can be completed without heating, while hydrolysis at room temperature is unlikely to occur, and a stable crosslinking reaction can be obtained, and this effect is particularly significant when an amine is present in the molecule.

[0054] The titanium-based chelating crosslinking agent has a Ti-OC bond in one molecule, and has the role of strengthening the intermolecular or intramolecular crosslinking bond of the resin by having this alkoxy group. Examples of the titanium-based chelating crosslinking agent include titanium alkoxide and titanium acylate. Examples of the titanium alkoxide include tetraisopropyl titanate, tetra-normal-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, and tetrastearyl titanate, as well as triethanolamine titanate, titanium acetylacetate, titanium ethylacetoacetate, titanium lactate, octylene glycol titanate, titanium tetraacetylacetate, and titanium phosphate compounds. Among them, titanium phosphate compounds and titanium acetylacetate are preferred. Examples of commercially available products include titanium TAA chelating agent (manufactured by BORICA): titanium acetylacetonate CAS: 17927-27-9. The amount of the chelating crosslinking agent blended is preferably 0.1 to 15 mass %, and more preferably 0.5 to 10 mass %, as the active ingredient of the chelating crosslinking agent, of the total solid content of the liquid printing ink.

[0055] (Organic solvent) The organic solvent used in the liquid printing ink of the present invention is not particularly limited, and examples thereof include aromatic hydrocarbon organic solvents such as toluene, xylene, Solvesso #100, Solvesso #150, etc., aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octane, decane, etc., and various ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc. Examples of water-miscible organic solvents include various organic solvents such as alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and glycol ethers such as ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di) methyl ether. These can be used alone or in combination of two or more.

[0056] From the viewpoints of both work hygiene during printing and the harmfulness of packaging materials, it is more preferable to use ethyl acetate, propyl acetate, isopropanol, normal propanol, etc., and not to use aromatic solvents such as toluene or ketone solvents such as methyl ethyl ketone.

[0057] (White pigment) In the present invention, the white pigment may be any white pigment that is commonly used in liquid printing inks, such as titanium oxide, barium sulfate, calcium carbonate, silica, zinc oxide, zinc sulfide, mica, talc, pearl, etc. Among these, titanium oxide is preferred, and it is preferable that the titanium oxide content be 80% by mass or more based on the total white pigment.

[0058] (Titanium dioxide) The titanium oxide used in the present invention is not particularly limited in its manufacturing method, shape, crystal form and particle size, and any known titanium oxide can be used. For example, the titanium oxide particles may be manufactured by the chlorine method or the sulfuric acid method. Those manufactured by the sulfuric acid method are preferred in terms of suppressing the wear of the doctor blade.

[0059] An example of a specific embodiment of the process for producing titanium oxide by the sulfuric acid method is as follows. (1) Dissolution process: Dried and crushed ilmenite ore is dissolved in sulfuric acid to produce titanium sulfate (TiOSO). 4 ) and ferrous sulfate (FeSO 4 ) solution. (2) Cooling and separation process: The raw solution is cooled to separate the crystallized ferrous sulfate (FeSO 4 7H 2 O) is separated using a centrifuge to obtain the original solution. (3) Hydrolysis process: The liquid from which ferrous sulfate has been separated is heated to produce titanium hydroxide (TiO(OH) 2 ) and sulfuric acid. (4) Calcination process: The white precipitate of titanium hydroxide obtained by the hydrolysis reaction is thoroughly washed with water, filtered, and then calcined at 900°C or higher to obtain rutile-type titanium dioxide (TiO 2 )

[0060] The crystal form of the titanium oxide particles may be rutile, anatase, or brookite. The rutile type is preferred in that a higher hiding power can be obtained. The average particle diameter of the titanium oxide particles is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm, and even more preferably 0.2 to 0.3 μm, in order to achieve high gloss and hiding power. If the average particle diameter of the titanium oxide particles is less than 0.1 μm, the hiding power decreases, and the doctor blade is likely to leave unscraped areas, which may cause plate fogging. If the average particle diameter of the titanium oxide particles exceeds 1.0 μm, the hiding power and gloss may decrease.

[0061] The titanium oxide preferably has a treatment layer made of at least alumina and / or silica on its surface. In titanium oxide surface-treated with alumina and / or silica, silica is generally used for the purpose of adjusting the acid-base state of the titanium oxide surface and for imparting durability to the resulting ink / paint film, while alumina is used for improving the wetting of titanium oxide during dispersion. Surface treatment methods for titanium oxide include aqueous treatment and gas phase treatment. From the viewpoint of dispersion stability, the ratio of the amount of silica and alumina treated is preferably 35% by mass or more and 80% by mass or less. The amount of the inorganic substance relative to titanium oxide is not necessarily limited, but is generally 30 parts or less relative to 100 parts of titanium oxide.

[0062] Titanium oxide surface-treated with silica and alumina may be a commercially available product, and is commercially available from titanium oxide manufacturers such as Ishihara Sangyo Kaisha, Ltd. and Teika Co., Ltd. For example, there are commercially available varieties in which the amount of silica treated is greater than the amount of alumina treated, and varieties in which the amount of alumina treated is greater than the amount of silica treated, and titanium oxide in which the amount of alumina treated falls within the above-mentioned ratio range can also be obtained.

[0063] The mass ratio of alumina and silica can be estimated from the amount of alumina and silica present together with titanium oxide on the surface of titanium oxide. The amount ratio of alumina and silica present can be confirmed by analyzing and comparing the amount of alumina or silica adsorbed on the surface of titanium oxide using fluorescent X-rays, ESCA, or the like. Measurement using fluorescent X-rays is particularly simple and highly accurate. Silica and alumina are present on the surface of titanium oxide, and some of them may exist as free particles, and the total amount can be measured by measuring using fluorescent X-rays. For quantitative analysis using fluorescent X-rays, an analytical method using a calibration curve using standard materials has been established. Therefore, by confirming the mass ratio of alumina and silica present on the surface of commercially available titanium oxide by fluorescent X-ray measurement, titanium oxide with various mass ratios can be used.

[0064] The liquid printing ink of the present invention may further contain, if necessary, an extender pigment, a leveling agent, a defoaming agent, a plasticizer, an infrared absorbing agent, an ultraviolet absorbing agent, an aromatic agent, a flame retardant, and the like.

[0065] The liquid printing ink of the present invention can be produced by dissolving and / or dispersing a binder resin, a white pigment, etc., in an organic solvent. Specifically, a white pigment dispersion is produced by dispersing a white pigment in an organic solvent with a binder resin, and the ink can be produced by blending one or more compounds selected from the phosphoric acid-modified compounds represented by general formulas (1) to (4) and, if necessary, other compounds, etc., with the resulting pigment dispersion.

[0066] The particle size distribution of the pigment in the pigment dispersion can be adjusted by appropriately adjusting the size of the grinding media of the dispersing machine, the packing rate of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, etc. As the dispersing machine, for example, a commonly used roller mill, ball mill, pebble mill, attritor, sand mill, etc. can be used. When air bubbles or unexpectedly large particles are contained in the ink, they degrade the quality of the printed matter, so it is preferable to remove them by filtration, etc. As the filter, a conventionally known filter can be used.

[0067] The viscosity of the ink produced by the above method is preferably in the range of 10 mPa s or more from the viewpoint of preventing sedimentation of the pigment and adequately dispersing it, and 1000 mPa s or less from the viewpoint of workability during ink production and printing. The above viscosity is measured at 25°C using a Tokimec B-type viscometer. The viscosity of the ink can be adjusted by appropriately selecting the types and amounts of raw materials used, the binder resin, the white pigment, the organic solvent, etc. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

[0068] The liquid printing ink of the present invention has excellent adhesion to various substrates and can be used for printing on paper, synthetic paper, thermoplastic resin films, plastic products, steel plates, etc., and is useful as an ink for gravure printing using a gravure printing plate made by electronic engraving or the like, or for flexographic printing using a flexographic printing plate made by a resin plate or the like, but excludes inks for inkjet systems in which ink is ejected from an inkjet nozzle without using a plate. That is, in the case of inkjet ink, ink droplets ejected from a nozzle directly adhere to a substrate to form a printed item, whereas in the case of the liquid printing ink of the present invention, the printing ink is first adhered to and transferred to a printing plate or printing pattern, and then the ink alone is again adhered to the substrate and dried as necessary to form a printed item. The film thickness of the printing ink formed by the gravure printing method or flexographic printing method using the liquid printing ink of the present invention is, for example, 10 μm or less, preferably 5 μm or less.

[0069] The substrate used in the present invention is not particularly limited, and may be a paper or plastic substrate commonly used in the gravure / flexographic printing field, or a soft packaging substrate used in the food packaging field. For example, the substrate may be a wood-free paper used for printing on packaging materials and packages for cosmetics, beverages, medicines, toys, equipment, etc., kraft paper, pure white roll paper, glassine paper, parchment paper, Manila cardboard, white cardboard, coated paper, art paper, imitation paper, thin paper, thick paper, polyethylene-coated paper, and various synthetic papers.

[0070] Examples of the film substrate include polyamide resins such as nylon 6, nylon 66, and nylon 46; polyester resins such as polyethylene terephthalate (hereinafter sometimes referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate; biodegradable resins such as polyhydroxycarboxylic acids such as polylactic acid, aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate); polyolefin resins such as polypropylene and polyethylene, polyimide resins, polyarylate resins, and mixtures thereof; and films and laminates thereof made of thermoplastic resins, among which films made of polyethylene terephthalate (PET), polyester, polyamide, polyethylene, and polypropylene can be preferably used. These substrate films may be unstretched or stretched films, transparent or matte films, and their manufacturing methods are not limited. The thickness of the substrate film is also not particularly limited, but it is usually within the range of 1 to 500 μm. The printing surface of the substrate film is preferably subjected to a corona discharge treatment, and aluminum, silica, alumina, etc. may be vapor-deposited thereon. EXAMPLES

[0071] The present invention will be described more specifically with reference to examples. In the following, all "parts" and "%" are based on mass. In the present invention, the number average molecular weight or weight average molecular weight (converted into polystyrene) was measured by gel permeation chromatography (GPC) using an HLC8220 system manufactured by Tosoh Corporation under the following conditions. Separation columns: four TSKgelGMHHR-N columns manufactured by Tosoh Corporation. Column temperature: 40°C. Mobile phase: tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml / min. Sample concentration: 0.4% by mass. Sample injection amount: 100 microliters. Detector: differential refractometer. The viscosity was measured at 25° C. using a Tokimec B-type viscometer.

[0072] (Preparation of nitrocellulose solution N) Nitrocellulose solution N was prepared by adding 70.8 parts of a mixture of isopropyl alcohol / ethyl acetate (mass ratio of 56 / 44) to 29.2 parts of industrial nitrocellulose L1 / 8 (nitrocellulose JIS K-6703-1995, viscosity (fall time) 1.6-2.9 seconds at a solution concentration of 25.0%, manufactured by Sichuan Nirocell Coporation) and mixing thoroughly.

[0073] Example 1 The mixture was prepared by mixing 7.5 parts of polyurethane resin (product name: Burnock ETL-780, number average molecular weight 9400) manufactured by DIC Corporation, 2 parts of the solid content of nitrocellulose solution N, 2 parts of the solid content of Marquid N0.32 (manufactured by Arakawa Chemical Industries Co., Ltd.) as a rosin-modified maleic acid resin, 0.14 parts of the solid content of a commercially available product with a solid content of 30% containing toluene solvent as a chlorinated polyolefin resin, and Watersol EF5460 (manufactured by DIC Corporation) as a phosphoric acid-modified compound. A white liquid printing ink was prepared by kneading a total of 100 parts of the following: 0.7 parts of solids of 1,000% ethyl acetate, 24.95 parts of propyl acetate, 16 parts of isopropyl alcohol, and 6 parts of methylcyclohexane. The total was 100 parts.

[0074] [Examples 2 to 4] According to the formulation shown in Table 1, a white liquid printing ink was prepared in the same manner as in Example 1.

[0075] [Comparative Examples 1 to 3] Of the formulations in Example 1, the one without the phosphoric acid-modified compound was designated Comparative Example 1. As shown in Table 2, the one with 1.0 part of non-phosphoric acid-modified epoxy acrylate (Luxidia V-5510, manufactured by DIC Corporation) instead of 0.7 part of the phosphoric acid-modified compound in Example 1 was designated Comparative Example 2, the one with 1.0 part of short-chain styrene-maleic anhydride copolymer instead of 0.7 part of the phosphoric acid-modified compound in Example 1 was designated Comparative Example 3, A white liquid printing ink was prepared in the same manner as in Example 1.

[0076] (Printing) The white liquid printing inks shown in Tables 1 and 2 were each measured for viscosity in seconds at 25°C using a Zahn Cup #4 (Rigo Co., Ltd.), and then adjusted to a viscosity of 15 seconds (25°C) using a Univia NT Reducer No. 3K (Rigo Co., Ltd.), a mixed solvent consisting of N-propyl acetate / methyl ethyl ketone / isopropyl alcohol / ethyl acetate in a mass ratio of 49 / 32 / 10 / 9. The inks were then applied to the two films using a Tester Sangyo Auto Proofer (plate: Helio 175L all solid), and left for 24 hours to produce prints.

[0077] Furthermore, the gloss of each of the resulting white liquid printing inks was measured at an incident angle of a light source of 60° using a gloss meter manufactured by BYK.

[0078] In addition, the following properties were evaluated for the substrates, biaxially oriented polypropylene film (abbreviated as OPP film, thickness 15 μm) and matte polypropylene film (abbreviated as matte PP film, thickness 15 μm).

[0079] [Adhesion] After 24 hours had passed since the color development, cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface of the print, which was then quickly peeled off and the condition of the printed surface was visually evaluated. (Evaluation Criteria) 5: The printing film does not peel off from the film at all. 4: Less than 25% of the area of ​​the printed film peels off from the film. 3: More than 25% but less than 50% of the area of ​​the printed film peels off from the film. 2: More than 50% but less than 75% of the area of ​​the printed film peels off from the film. 1: 75% or more of the printed surface area peels off from the film.

[0080] [Scratch resistance] 24 hours after the printing, the printed surface of the print was rubbed back and forth with a fingernail 20 times, and the state of ink absorption was visually evaluated. (Evaluation Criteria) 5: The printing film does not peel off from the film at all. 4: Less than 25% of the area of ​​the printed film peels off from the film. 3: More than 25% but less than 50% of the area of ​​the printed film peels off from the film. 2: More than 50% but less than 75% of the area of ​​the printed film peels off from the film. 1: 75% or more of the printed surface area peels off from the film.

[0081] [PVC blocking resistance] Each of the prints obtained was cut into pieces measuring 5 cm x 5 cm, and two types of commercially available tablecloths (soft polyvinyl chloride sheets) cut to the same size, one with an antibacterial surface and one with a reversible check pattern, were placed on top of each other and weighed at 0.5 kg / cm. 2 After leaving it for 24 hours in an atmosphere of 50°C and 80% humidity, the printed surface and the polyvinyl chloride sheet were peeled off, and the PVC blocking resistance was evaluated based on the degree of ink peeling. (Evaluation Criteria) 5: The printing film did not peel off at all. 4: The area where the printed layer has peeled off from the film is 20% or more but less than 50%. 3: The area where the printed layer has peeled off from the film is 50% or more but less than 75%. 2: The area where the printed layer has peeled off from the film is 75% or more but less than 90%. 1: The area where the printing film has peeled off from the film is 90% or more.

[0082] [Heat resistance] 24 hours after the printing, the printed surface of the printed matter was subjected to a heat seal test using a heat seal tester manufactured by Tester Sangyo Co., Ltd., equipped with a hot plate with a thermal gradient of 80 to 200°C. The printed surface was then pressed against the aluminum foil at 2.0 kg / cm 2 The pressure was applied for one second. Heat resistance was evaluated based on the minimum temperature at which the ink on the printed surface transferred to the aluminum foil. (Evaluation Criteria) 5: Over 180℃. 4: Above 160℃ and below 180℃. 3: Above 140°C and below 160°C. 2: Above 120℃ and below 140℃. 1: Less than 120℃.

[0083] [Oil resistance] 24 hours after the printing, butter (Snow Brand Hokkaido Butter) melted at 40°C is applied to the printed surface of the printed material, which is then left to stand at 25°C for 24 hours. Next, using a Daiei Scientific Instruments Manufacturing Co., Ltd. Gakushin-type abrasion resistance tester, the print was rubbed 100 times with a test white cloth (Kanakin No. 3) under a load of 200 g, and the oil resistance was evaluated from the change in the printed surface. (Evaluation Criteria) 5: No change to the printed surface or the pad. 4: There is no change in the printed surface, but the patch cloth becomes discolored. 3: Streaky scratches are observed on the printed surface. 2: Thick streak-like scratches are observed on the printed surface. 1: Surface scratches are observed on the printed surface.

[0084] [Alcohol resistance] The printed surface of the print 24 hours after application was rubbed 30 times with a cloth soaked in ethanol under a load of 200 g using a Gakushin type abrasion resistance tester, and the alcohol suitability was evaluated from the change in the printed surface. (Evaluation Criteria) 5: No change to the printed surface or the pad. 4: There is no change in the printed surface, but the patch cloth becomes discolored. 3: Streaky scratches are observed on the printed surface. 2: Thick streak-like scratches are observed on the printed surface. 1: Surface scratches are observed on the printed surface.

[0085] The formulations of each white liquid printing ink and the evaluation results are shown in Tables 1 and 2. The blank spaces in the table indicate that no blend was used.

[0086] [Table 1]

[0087] [Table 2]

[0088] The liquid printing ink of the present invention has excellent adhesion to a substrate, scratch resistance, heat resistance, oil resistance, alcohol resistance, PVC blocking resistance, and gloss.

Claims

1. A liquid printing ink comprising a white pigment, a binder resin, and one or more compounds selected from the group consisting of phosphoric acid modified compounds represented by general formula (1) and general formula (2). 【Chemistry 1】 （１） 【Chemistry 2】 （２） In general formulas (1) to (2), R １ , R ２ , R ３ each independently represents an epoxy resin or modified epoxy resin having a number average molecular weight of 500 to 3,000.

2. 2. The liquid printing ink according to claim 1, wherein the binder resin is a cellulose resin, a urethane resin, a rosin resin, or a chlorinated polyolefin resin.

3. 3. The liquid printing ink according to claim 1, further comprising a titanium-based chelate crosslinking agent.

4. A liquid printing ink according to any one of claims 1 to 3 for printing on plastic films or paper.

5. A printed matter obtained by using the liquid printing ink according to any one of claims 1 to 4.

6. A packaging material obtained by using the liquid printing ink according to any one of claims 1 to 4.

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