JP2021152150A - Varnish for active energy ray-curable lithographic ink, active energy ray-curable lithographic ink, and method for manufacturing printed matter using the same - Google Patents

Abstract

To achieve both storage stability of a varnish for active energy ray-curable lithographic printing, and printability of ink using the varnish.SOLUTION: A varnish for active energy ray-curable lithographic ink contains (1) an acrylic resin having an acid value of 100 mgKOH/g or more and 250 mgKOH/g or less, and (2) a resin composition containing at least two or more kinds of ethylenically unsaturated compounds having ethylene oxide groups, in which the ethylenically unsaturated compound is the following (A) and (B): (A) a (meth)acrylate compound having 4 or more and less than 10 ethylene oxide groups in one molecule and (B) a (meth)acrylate compound having 10 or more and less than 20 ethylene oxide groups in one molecule. A moisture content value obtained by measuring the composition by a Karl Fischer method is 0.2 mass% or more and less than 5.0 mass%.SELECTED DRAWING: None

Description

The present invention relates to a varnish for active energy ray-curable slab ink, an active energy ray-curable slab ink, and a method for producing a printed matter using the varnish.

From the viewpoint of dealing with environmental problems and preserving the working environment in recent years, efforts are underway to reduce VOCs by significantly reducing the use of volatile petroleum-based solvents in various printing fields.

Planographic printing is a printing method that is widely used as a system for supplying printed matter at high speed, in large quantities, and at low cost, and includes lithographic printing with water and lithographic printing without water.

In lithographic printing with water, the dampening water used in large quantities for image formation contains a large amount of volatile solvent, which poses a problem in terms of work and environment.

On the other hand, in waterless lithographic printing, silicone rubber or fluororesin is used for the non-image area, and no dampening water is required.

Since a large amount of petroleum-based solvent is also used in general lithographic printing ink, it is desired to make the ink water-based or solvent-free. The use of printing ink, which can be instantly cured by irradiating it with active energy rays such as ultraviolet rays, is expanding in many fields due to its high equipment, safety, environment, and productivity. In addition, since a large amount of petroleum-based solvent is used as a cleaning agent for inks used in the printing process, the development of printing inks that can use water-based cleaning agents that do not contain volatile solvents is progressing. Has been done.

Patent Document 1 discloses an active energy ray-curable coating material having excellent wear resistance and toughness by using an acrylic polymer having a hydrophilic functional group with respect to a polyfunctional (meth) acrylate monomer and a polyfunctional acrylate oligomer. Has been done. Patent Document 2 discloses a lithographic printing ink excellent in water washability, ground stain resistance, and water resistance of a cured film by containing a pigment, a resin having an ethylenically unsaturated group and a hydrophilic group. ing. In Patent Document 3, an active energy ray-curable flat plate ink having excellent misting resistance and ground stain resistance is used by using a copolymer resin of styrenes, (meth) acrylic acid alkyl ester and a hydrophilic group-containing vinyl monomer. The varnish for use is disclosed.

Japanese Unexamined Patent Publication No. 2012-82287 International Publication No. 2017/047817 Japanese Unexamined Patent Publication No. 2019-143136

However, the varnish used in the conventional water-washable lithographic printing ink tends to change its properties such as white turbidity, thickening, and gelation with time, and has a problem in storage stability. Further, the ink using the varnish that has changed with time has a problem that the inking on the printing plate becomes poor and printing defects occur.

That is, the present invention contains (1) an acrylic resin having an acid value of 100 mgKOH / g or more and 250 mgKOH / g or less, and (2) at least two kinds of ethylenically unsaturated compounds having an ethylene oxide group. However, (A) a (meth) acrylate compound having 4 or more and less than 10 ethylene oxide groups in one molecule, and (B) a (meth) acrylate compound having 10 or more and less than 20 ethylene oxide groups in one molecule. An active energy ray-curable flat plate characterized in that a resin composition has a water content of 0.2% by mass or more and less than 5.0% by mass when the composition is measured by the curl Fisher method. The present invention relates to an ink varnish, an active energy ray-curable flat plate ink containing the varnish and a pigment, and a method for producing a printed matter using the ink.

The present invention provides a varnish for active energy ray-curable lithographic ink, which is excellent in storage stability and suppresses white turbidity, thickening and gelation. Further, the present invention provides an active energy ray-curable flat plate ink containing the varnish for active energy ray-curable flat plate ink and a pigment, and a printed matter using the ink.

Hereinafter, the present invention will be specifically described.

The varnish for active energy ray-curable flat plate ink of the present invention contains (1) an acrylic resin having an acid value of 100 mgKOH / g or more and 250 mgKOH / g or less, and (2) at least two ethylenically unsaturated compounds having an ethylene oxide group. The ethylenically unsaturated compound includes (A) a (meth) acrylate compound having 4 or more and less than 10 ethylene oxide groups in one molecule, and (B) 10 or more and 20 ethylene oxide groups in one molecule. It is a resin composition which is less than 0.2 (meth) acrylate compounds, and contains 0.2% by mass or more and less than 5.0% by mass of water when the resin composition is measured by the curl fisher method.

The acid value of the resin is preferably 100 mgKOH / g or more and 250 mgKOH / g or less. The acid value of the resin is preferably 100 mgKOH / g or more, more preferably 150 mgKOH / g or more, and 190 mgKOH / g or more, in order to obtain good solubility and pigment dispersibility of the copolymer in an aqueous cleaning solution. It is particularly preferable that it is g or more. Further, in order to obtain solubility in (2) an ethylenically unsaturated compound having an ethylene oxide group, which will be described later, it is preferably 250 mgKOH / g or less, more preferably 230 mgKOH / g or less, and particularly 220 mgKOH / g or less. preferable. The acid value of the resin can be determined in accordance with the neutralization titration method of Section 3.1 of the test method of JIS K 0070: 1992.

The resin can include a styrene skeleton structure and a (meth) acrylic acid alkyl ester structure. Examples of the compound having a styrene skeleton structure include styrene, α-methylstyrene, and a styrene compound having at least one alkyl group having 1 to 4 carbon atoms in the aromatic ring. The elasticity and stacking interaction derived from the aromatic ring skeleton can be adjusted to a varnish viscosity suitable for pigment dispersion. The content of the styrene skeleton structure of the resin is preferably 40% by mass or more and less than 65% by mass, more preferably 45% by mass or more and less than 60% by mass, and 50% by mass or more and less than 55% by mass. Is even more preferable. If it is less than 40% by mass, the pigment dispersibility is lowered and the print quality is likely to be lowered. When the content of the styrene skeleton structure is 65% by mass or more, the solubility in the ethylenically unsaturated compound becomes poor, so that the viscosity of the varnish and the ink becomes high, the pigment dispersibility is lowered, and proper printing is performed. Problems such as the inability to obtain the concentration, the problem that it takes a long time to manufacture the varnish, and the precipitation of the resin during storage of the varnish and the ink occur. The content of the styrene skeleton structure contained in the resin can be measured by NMR analysis after eluting the resin from the varnish for active energy ray-curable flat plate ink by gel permeation chromatography (GPC).

Examples of the compound having the (meth) acrylic acid alkyl ester structure include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2- (meth) acrylate. Ethylhexyl, isononyl (meth) acrylate, dodecyl (meth) acrylate and the like can be mentioned. These can be used alone or in combination of two or more. Of these, the alkyl group of the (meth) acrylic acid alkyl ester has 1 to 1 carbon atoms from the viewpoint of reducing the compatibility with the ink repulsive diluent and preventing the surface stain of the silicone rubber. It is preferably 3.

The copolymer component of the resin may contain a hydrophilic group-containing vinyl monomer in order to achieve both solubility in water and good dispersibility of the pigment. Specific examples thereof include (meth) acrylic acid, (meth) acrylic acid dimer, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-acryloyloxyethyl phthalic acid. Be done. These can be used alone or in combination of two or more. The content of the hydrophilic group-containing vinyl monomer is preferably 20% by mass or more and less than 50% by mass, more preferably 25% by mass or more and less than 45% by mass, and 30% by mass or more and less than 40% by mass. It is more preferable to have. When the content is within the above range, the varnish for active energy ray-curable slab ink and the active energy ray-curable slab ink can have both solubility in water and good pigment dispersibility.

The method for polymerizing the resin is not particularly limited. Preferably, it is a method of radically polymerizing a monomer component using a radical polymerization initiator in the presence of a solvent or a chain transfer agent, if necessary. When a solvent is used in the polymerization of the resin, known ones such as an aromatic hydrocarbon solvent, a ketone solvent, an ether solvent, an alcohol solvent, and an ester solvent can be used. Specific examples thereof include toluene, xylene, ethylbenzene, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, butyl acetate and ethyl acetate. In addition, one of these may be used alone, or two or more thereof may be used in combination. The solvent is preferably used in the range of 50 to 300 parts by mass with respect to 100 parts by mass of all the monomer components.

The radical polymerization initiator is not particularly limited, and known substances such as inorganic peroxides, organic peroxides, and azo compounds can be used. Specifically, inorganic peroxides such as ammonium persulfate and potassium persulfate, benzoyl peroxide, t-butylperoxyacetate, 2,2-di- (t-butylperoxy) butane, and t-butylperoxybenzoate. , N-Butyl-4,4-di- (t-butylperoxy) valerate, di- (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5 , -Dimethyl-2,5, -di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, diisopropylbenzene hydroperoxide, p-menthan hydroperoxide, 1,1 , 3,3,-Tetramethylbutylhydroperoxide, cumenehydroperoxide, organic peroxides such as t-butylhydroperoxide and t-butyltrimethylsilyl peroxide, 1-[(1-cyano-1-methylethyl) ) Azo] formamide, 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis (N-cyclohexyl-2-methylpropionamide) and 2,2'-azobis (2, 4,4-trimethylpentane), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile) And the like, azo compounds and the like can be mentioned. In addition, one of these may be used alone, or two or more thereof may be used in combination. The radical polymerization initiator is preferably used in the range of 0.1 to 30 parts by mass with respect to 100 parts by mass of all the monomer components.

The weight average molecular weight of the resin is preferably 17,500 or more, and more preferably 20,000 or more, in order to give the ink appropriate viscosity and fluidity. Further, in order to obtain water solubility of the resin, it is preferably 100,000 or less, more preferably 50,000 or less, and further preferably 30,000 or less. The weight average molecular weight can be obtained by measuring in terms of polystyrene using GPC.

The content of the resin contained in the active energy ray-curable printing varnish of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more in order to obtain the viscosity of the ink required for printing. .. Further, in order to obtain the fluidity of the ink required for printing and the transferability between rollers, it is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 40% by mass or less.

(Ethylene unsaturated compound)
The varnish for active energy ray-curable flat plate ink of the present invention contains (2) at least two kinds of ethylenically unsaturated compounds having ethylene oxide groups, and (A) each has 4 or more and less than 10 ethylene oxide groups in one molecule. It contains a (meth) acrylate compound and (B) a (meth) acrylate compound having 10 or more and less than 20 ethylene oxide groups in one molecule.

The ethylenically unsaturated compound contained in the varnish for active energy ray-curable flat plate ink of the present invention is a component that polymerizes by radicals generated from a photopolymerization initiator, which will be described later, to increase the molecular weight, and contains monomers, oligomers, and the like. It is an ingredient called. The monomer has an ethylene oxide group and an ethylenically unsaturated group, and is a component that polymerizes to increase the molecular weight as described above, but in the state before polymerization, it is often a liquid component having a relatively low molecular weight. It is also used as a solvent for dissolving a resin to form a varnish, and for adjusting the viscosity of an ink composition.

The ethylenically unsaturated compound used in the present invention is used for the purpose of adjusting the viscosity and storage stability of the varnish, and further the viscosity and curability of the flat plate ink made by using the varnish, and specifically ( 2) At least two or more kinds of ethylenically unsaturated compounds having an ethylene oxide group are mixed and used.

The ethylenically unsaturated compound contained in the varnish for active energy ray-curable flat plate ink of the present invention includes a (meth) acrylate compound (A) having 4 or more and less than 10 ethylene oxide groups in the one molecule. Since the (A) (meth) acrylate compound has a low viscosity, the viscosity can be widely adjusted, and the curing sensitivity of the active energy ray-curable flat plate ink can be improved by using the varnish. Specifically, methoxypolyethylene glycol # 400 (meth) acrylate, methoxy-polyethylene glycol (meth) acrylate, EO-modified nonylphenol (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, α, α', α'' -Propane-1,2,3-triyltris [ω- (acryloyloxy) poly (oxyethylene)], methoxypolyethylene glycol # 400 (meth) methacrylate, pentaerythritol triacrylate ethylene oxide adduct, pentaerythritol tetra (meth) acrylate ethylene oxide Additives and the like can be mentioned. These can be used alone or in combination of two or more.

Further, the varnish for active energy ray-curable flat plate ink of the present invention also contains a (meth) acrylate compound (B) having 10 or more and less than 20 ethylene oxide groups in one molecule. Since the (B) (meth) acrylate compound exhibits good compatibility with a resin having a high acid value, the storage stability of the varnish can be improved. Specifically, methoxypolyethylene glycol # 550 acrylate, polyethylene glycol diacrylate 600, propoxylated ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate ethylene oxide adduct, penta. Examples thereof include erythritol tetra (meth) acrylate ethylene oxide adduct. These can be used alone or in combination of two or more.

The proportion of the (meth) acrylate compound (A) among the (2) ethylenically unsaturated compounds having an ethylene oxide group contained in the varnish for active energy ray-curable flat plate ink of the present invention appropriately maintains the pigment dispersibility. Of the (meth) acrylate compound (A) and the (meth) acrylate compound (B), in order to adjust the viscosity to a varnish that can be obtained and to maintain the curing sensitivity of the active energy ray-curable flat plate ink using the varnish appropriately. With respect to the total content, 50% or more is preferable, and 60% or more is more preferable. Further, in order to suppress white turbidity and thickening / gelling of the varnish and obtain long-term storage stability, less than 95% is preferable, and less than 80% is more preferable. The contents of the (meth) acrylate compound (A) and the (meth) acrylate compound (B) contained in the varnish are separated from the varnish for active energy ray-curable flat plate ink by gel permeation chromatography (GPC). After that, each sample can be measured by NMR analysis.

The oligomer is a component that polymerizes to increase the molecular weight as described above, but since it is a component having a relatively high molecular weight, it is also used for the purpose of imparting appropriate viscosity and elasticity to the ink composition. Examples of the oligomer include epoxy-modified (meth) acrylate and rosin-modified epoxy, which are exemplified by the ester of a hydroxyl group and (meth) acrylic acid generated after the epoxy group contained in an epoxy compound such as an epoxy resin is opened with an acid or a base. Esters of polyester-modified (meth) acrylates, which are exemplified by esters of acrylates, terminal hydroxyl groups of dibasic acids and diols, and (meth) acrylic acids, and esters of terminal hydroxyl groups of polyether compounds with (meth) acrylic acids. Examples thereof include polyether-modified (meth) acrylates and polyisocyanate compounds.

The content of the ethylenically unsaturated compound in the varnish is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, and particularly preferably 50 to 80% by mass. When the content of the ethylenically unsaturated compound is in the above range, both good curability and printability can be achieved at the same time.

Pentaerythritol tetra A (meth) acrylate ethylene oxide adduct can be preferably used.

(Varnish moisture content)
The changes in properties such as whitening, thickening, and gelation of the varnish, which have been problems in the past, are affected by the low solubility of the acrylic resin in the ethylenically unsaturated compound. That is, when the acid value of the acrylic resin is 100 mgKOH / g or more, the solubility in the ethylenically unsaturated compound decreases, so that the hydrophilic groups derived from the resin easily form self-associates by hydrogen bonding. As a result, agglomeration and precipitation of the resin and thickening of the varnish occur. In addition, radical components are generated from the acrylic resin over time. Generally, a method of adding a polymerization inhibitor to a varnish in advance to suppress radical polymerization is adopted, but since the resin used in the present invention has a high acid value, the action of the polymerization inhibitor is likely to be inhibited, and radical polymerization is carried out. As the polymerization progresses, it becomes easier to gel. In order to suppress the above-mentioned property change, the dissolution stability of the acrylic resin and the activation of the polymerization inhibitor are important, and these can be achieved by appropriately controlling the water content in the varnish.

The varnish for active energy ray-curable flat plate ink of the present invention contains water content of 0.2% by mass or more and less than 5.0% by mass as measured by the Karl Fischer method. The water content in the varnish is preferably 0.5% by mass or more and 3.0% by mass or less, and more preferably 0.8% by mass or more and 1.5% by mass or less. If the water content is within the above range, the solubility of the resin can be kept stable by the electrostatic repulsion action due to the ionization of the hydrophilic groups of the acrylic resin by increasing the polarity of the varnish. Further, in order to activate the polymerization inhibitor, the inhibitor needs to generate a radical intermediate via an oxidation reaction, and if 0.2% by mass or more of water is present in the varnish, the resin acid The effect of promoting the oxidation reaction can be obtained even under acidic conditions depending on the value. If the water content is more than 5.0% by mass, the saturated water content of the ethylenically unsaturated compound may be exceeded and phase separation may occur. The moisture content can be measured by the Karl Fischer method by attaching the moisture vaporizer EV-2000 (manufactured by Hiranuma Sangyo Co., Ltd.) to the trace moisture measuring device AQ2200A (manufactured by Hiranuma Sangyo Co., Ltd.).

(Polymerization inhibitor)
The varnish for active energy ray-curable lithographic ink of the present invention can also be added with a polymerization inhibitor in order to improve stability during storage. Specific examples of polymerization inhibitors include hydroquinone, hydroquinone monoesters, phenothiazines, pt-butylcatechol, N-phenylnaphthylamine, 2,6-di-t-butyl-p-methylphenol, chloranyl, etc. Pyrogallol, nitroso compounds, polyfunctional amine compounds and the like can be mentioned. The varnish for active energy ray-curable flat plate ink of the present invention acts as a compatibilizer that uniformly diffuses and dissolves the acrylic resin, and from the viewpoint of storage stability of the varnish and ink, a nitroso compound and a polyfunctional amine compound. Any one or more compounds selected from the above are particularly preferably used. The nitroso compound and the polyfunctional amine compound have an excellent effect on an acrylic resin having a particularly high cohesive power and a high acid value. The nitroso compound and the polyfunctional amine compound inhibit the interaction related to the aggregation of the resins such as hydrogen bond and ionic bond generated by the hydrophilic group of the acrylic resin, and in the (2) ethylenically unsaturated compound, the resin is used. It can be stabilized in a uniform diffused or dissolved state. Specific examples of the nitroso compound and the polyfunctional amine compound include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) and 2,2,6,6-tetramethylpiperidine. N-oxyl compounds such as -1-oxyl (TEMPO), nitroso compounds such as aluminum N-nitrosophenyl hydroxylamine and N-nitrosodiphenylamine, Jeffamine T403 (trifunctional polyetheramine manufactured by Tomoe Kogyo Co., Ltd.), Jeffer Examples thereof include polyfunctional amine compounds such as Min D400 (manufactured by Tomoe Kogyo Co., Ltd., bifunctional polyether amine) and Jeffamine D230 (manufactured by Tomoe Kogyo Co., Ltd., bifunctional polyether amine).

As the nitroso compound and the polyfunctional amine compound used in the varnish for active energy ray-curable flat plate ink of the present invention, the nitroso compound is preferably used from the viewpoints of low cost and less coloring of the varnish even when added. Be done. Furthermore, more preferably, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, and aluminum N-nitrosophenylhydroxylamine.

The contents of the nitroso compound and the polyfunctional amine compound contained in the varnish for active energy ray-curable flat plate ink according to the present invention are (1) acrylic resin, (2) ethylenically unsaturated compound, nitroso compound and polyfunctional. When the total amount of the amine compounds is 100 parts by mass, 0.01 parts by mass or more is preferable from the viewpoint of suppressing aggregation and precipitation of (1) acrylic resin in the varnish over time and improving storage stability. , 0.05 parts by mass or more is more preferable, and 0.1 parts by mass or more is further preferable. On the other hand, (1) 0.4 parts by mass or less is preferable, 0.35 parts by mass or less is more preferable, and 0.3 parts by mass or less is preferable from the viewpoint of suppressing a remarkable decrease in viscosity due to promotion of compatibility of the acrylic resin and cost. Is even more preferable.

The content of the nitroso compound and the polyfunctional amine compound contained in the active energy ray-curable flat plate ink according to the present invention suppresses the thickening of the ink over time when the total amount of the ink is 100 parts by mass. From the viewpoint of improving storage stability, 0.005 parts by mass or more is preferable, 0.025 parts by mass or more is more preferable, and 0.05 parts by mass or more is particularly preferable. On the other hand, from the viewpoint of maintaining appropriate viscosity and fluidity, 0.2 parts by mass or less is preferable, 0.18 parts by mass or less is more preferable, and 0.15 parts by mass or less is particularly preferable.

(Salt addition)
An alkali metal salt and / or an alkaline earth metal salt is added to the varnish for active energy ray-curable flat plate ink of the present invention for the purpose of improving and stabilizing the solubility of the acrylic resin in an ethylenically unsaturated compound. You may. As the alkali metal salt, lithium salt, sodium salt, potassium salt, rubidium salt and cesium salt derived from an organic acid or an inorganic acid are preferable. For deprotonation and ionization of the carboxyl group, which contributes to the solubility and stabilization of the acrylic resin, the smaller the ionic radius of the metal ion, the stronger the attraction to the carboxylic acid ion, so that the lithium salt, sodium salt, and potassium salt are more suitable. preferable. As the alkaline earth metal salt, beryllium salt, magnesium salt, calcium salt, strontium salt and barium salt derived from organic acid or inorganic acid are preferable, and magnesium salt is more preferable from the viewpoint of ionic radius. Further, one kind of the metal salt may be used alone, or two or more kinds thereof may be used in combination.

As the counter anion species paired with the alkali metal atom or the alkaline earth metal atom, any anion species derived from either an organic acid or an inorganic acid can be used. Specific examples of the organic acid include linear aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, capric acid, lauric acid and myristic acid. Acids, branched aliphatic carboxylic acids as these structural isomers, aromatic carboxylic acids, alcorbic acids, sulfonic acids, thioacetic acids and the like can be mentioned. Specific examples of the inorganic acid include hydrofluoric acid, hydrochloric acid, hydrogen bromide, hydrogen iodide, sulfuric acid, sulfurous acid, thiosulfuric acid, nitrate, nitrite, phosphoric acid, carbonic acid, metasilicic acid, tetraboric acid, and thiosian acid. And so on. From the viewpoint of deprotonation and ionization of the carboxyl group that contributes to the solubility and stabilization of the copolymer resin, an anion species having a high electronegativity is preferable, and in particular, an alkali having a chlorine atom, a bromine atom and an iodine atom as counter anions. Metal compounds or alkaline earth metal compounds are preferred.

Specifically, the alkali metal salt preferably used in the varnish for active energy ray-curable flat plate ink of the present invention is lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, iodide. Examples thereof include lithium, sodium iodide and potassium iodide, and examples of the alkaline earth metal salt include magnesium chloride, magnesium bromide and magnesium iodide. As these, one kind of the said metal compound may be used alone, or two or more kinds may be used in combination.

(Amount of salt added)
The total content of the alkali metal salt and the alkaline earth metal salt that can be contained in the varnish for active energy ray-curable flat plate ink of the present invention is preferably 30 ppm or more and 3000 ppm or less. The content is more preferably 200 ppm or more and 2000 ppm or less, and further preferably 500 ppm or more and 1500 ppm or less. When the total content of the alkali metal salt and the alkaline earth metal salt is within the above range, deprotonation / ionization of the carboxyl group that contributes to the solubility / stabilization of the acrylic resin is promoted, and the varnish becomes cloudy. And thickening can be suppressed. If the content is more than 3000 ppm, it precipitates in the varnish, and when printing is performed using an ink produced from this varnish as a raw material, the print quality is deteriorated.

The content of the alkali metal salt and the alkali metal and the alkaline earth metal derived from the alkaline earth metal salt contained in the varnish for the active energy ray-curable flat plate ink of the present invention is determined by the ICP emission spectroscopic analyzer (Hitachi High-Tech Science Co., Ltd.). It can be measured using PS3520- VDDII) manufactured by PS3520- VDDII).

(others)
The varnish for active energy ray-curable lithographic ink of the present invention may further contain an ink repulsive diluent. Specifically, it preferably contains one or more components selected from silicone liquids, alkyl acrylates, hydrocarbon solvents, and fluorocarbons. It may also contain vegetable oils or fatty acid esters derived from vegetable oils. The ink-repulsive diluent has an effect of reducing ink adhesion to silicone rubber, which is a non-image area of a waterless lithographic printing plate. The reason for reducing the ink adhesion to silicone rubber is presumed as follows. That is, the ink repulsive diluent contained in the ink diffuses from the ink by contact with the surface of the silicone rubber and covers the surface of the silicone rubber in a thin film form. It is presumed that the thin film thus formed prevents the ink from adhering to the surface of the silicone rubber and prevents the surface of the silicone from becoming dirty.

Among the ink repulsive diluents, alkyl acrylates are preferable because they cure when irradiated with active energy rays, and thus improve the strength of the cured film of the ink and at the same time improve the sensitivity to active energy rays. Specifically, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth). ) Acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, isooctadecyl (meth) acrylate and the like can be mentioned.

The content of the ink repulsive diluent in the varnish is preferably 0.2% by mass or more because the active energy ray-curable flat plate ink has good ground stain resistance. More preferably, it is 0.5% by mass or more, and further preferably 1% by mass or more. Further, 20% by mass or less is preferable because the storage stability of the active energy ray-curable lithographic ink is good. More preferably, it is 15% by mass or less, and further preferably 10% by mass or less.

(Varnish viscosity)
The viscosity of the varnish for active energy ray-curable flat plate ink of the present invention is preferably 40 Pa · s or more and 200 Pa · s or less when measured at 25 ° C. and 0.5 rpm using a cone plate type rotary viscometer. .. Since the active energy ray-curable lithographic ink of the present invention has good ground stain resistance, the viscosity of the varnish is preferably 40 Pa · s or more, more preferably 50 Pa · s or more, and even more preferably 60 Pa · s or more. Further, since the fluidity of the active energy ray-curable lithographic ink is good, the viscosity of the varnish is preferably 200 Pa · s or less, more preferably 150 Pa · s or less, and further preferably 100 Pa · s or less.

(Varnish manufacturing method)
The method for producing the varnish for active energy ray-curable lithographic ink of the present invention will be described below. The varnish for active energy ray-curable flat plate ink of the present invention comprises (2) an ethylenically unsaturated compound to which a polymerization inhibitor is added, and if necessary, heated and stirred at 50 to 120 ° C., and then (1) an acrylic resin. In addition, if necessary, an ink repulsive diluent, water, an aqueous solution of an alkali metal salt and / or an alkaline earth metal salt and other components are added, and then the mixture is cooled to room temperature.

(Inking)
The active energy ray-curable slab ink of the present invention preferably contains the varnish and pigment for the active energy ray-curable slab ink of the present invention. The active energy ray-curable lithographic ink has high viscosity and excellent fluidity. Further, since the active energy ray-curable lithographic ink has a high viscosity, it has excellent ground stain resistance. Furthermore, printed matter using active energy ray-curable lithographic ink shows high gloss.

The active energy ray-curable flat plate ink preferably contains 35% by mass or more and 90% by mass or less of the varnish for the active energy ray-curable flat plate ink. Since the active energy ray-curable lithographic ink has excellent pigment dispersibility and good ground stain resistance during printing, the content is preferably 40% by mass or more, more preferably 45% by mass or more, and 50% by mass or more. More preferred. Since the fluidity of the active energy ray-curable lithographic ink can be obtained, the content is preferably 80% by mass or less, more preferably 75% by mass or less, still more preferably 70% by mass or less.

As the pigment, at least one selected from inorganic pigments and organic pigments generally used in lithographic inks can be used.

Specific examples of the inorganic pigment used in the present invention include titanium dioxide, calcium carbonate, barium sulfate, red iron oxide, cadmium red, chrome yellow, zinc yellow, dark blue, ultramarine blue, organic bentonite, alumina white, iron oxide, carbon black, graphite, and the like. Examples include aluminum.

Examples of organic pigments include phthalocyanine pigments, soluble azo pigments, insoluble azo pigments, azolake pigments, quinacridone pigments, isoindolin pigments, slen pigments, metal complex pigments, and the like, and specific examples thereof include phthalocyanine. Examples thereof include blue, phthalocyanine green, azo red, mono azo red, mono azo yellow, disazo red, disazo yellow, quinacridone red, quinacridone magenta, and isoindrin yellow.

These pigments can be used alone or in admixture of two or more.

The pigment concentration contained in the active energy ray-curable lithographic ink of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more in order to obtain the printing paper surface density. Further, since the active energy ray-curable lithographic ink has good fluidity, the content is preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less.

The active energy ray-curable lithographic ink of the present invention preferably contains a photopolymerization initiator in order to improve the sensitivity. In addition, a sensitizer may be included to assist the effect of the photopolymerization initiator. There are mechanically different types of such photopolymerization initiators, such as a single molecule system direct cleavage type, an ion pair electron transfer type, a hydrogen abstraction type, and a two molecule complex system, and they can be selected and used.

The photopolymerization initiator used in the present invention is preferably one that generates an active radical species, and specific examples thereof include 4,4-bis (dimethylamino) benzophenone (also known as Michler ketone), α-hydroxyacetophenone, and α. -Aminoacetophenone, acylphosphine oxide, titanocene, o-acyloximes, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propan-1-one, 2-benzyl-2-dimethylamino Examples thereof include -1- (4-morpholinophenyl) -butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenyl-phosphine oxide and the like. Specific examples of the sensitizer include 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 4,4-bis (diethylamino) -benzophenone, 4,4-bis (dimethylamino) chalcone, and p-dimethylaminocinna. Examples thereof include millidenindanone, 1,3-bis (4-dimethylaminobenzal) acetone, N-phenyl-N-ethylethanolamine, ethyl diethylaminobenzoate, 3-phenyl-5-benzoylthiotetrazole and the like.

In the present invention, one or more photopolymerization initiators and sensitizers can be used.

The content of the photopolymerization initiator is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, because the active energy ray-curable flat plate ink can obtain good sensitivity. .. Since the storage stability of the active energy ray-curable lithographic ink is improved, the content is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less. When a sensitizer is added, the content thereof is preferably 0.1% by mass or more, more preferably 1% by mass or more, because the active energy ray-curable lithographic ink can obtain good sensitivity. More preferably by mass% or more. The content is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, because the storage stability of the active energy ray-curable lithographic ink is improved.

The active energy ray-curable lithographic ink of the present invention preferably contains a pigment dispersant. Although the optimum content varies depending on the density, particle size, surface area, etc. of the pigment used, the pigment dispersant acts on the surface of the pigment and suppresses the aggregation of the pigment. By improving the pigment dispersibility of the active energy ray-curable flat plate ink, the fluidity of the active energy ray-curable flat plate ink is improved.

The content of the pigment dispersant is preferably 5% by mass or more and 50% by mass or less because the fluidity of the active energy ray-curable flat plate ink is improved with respect to the pigment.

The active energy ray-curable flat plate ink of the present invention can use additives such as wax, antifoaming agent, and transferability improver, if necessary.

The method for producing the active energy ray-curable lithographic ink of the present invention will be described. The active energy ray-curable flat plate ink of the present invention is a varnish for active energy ray-curable flat plate ink of the present invention, together with pigments, additives, and other components, as well as a kneader, a three-roll mill, a ball mill, a planetary ball mill, a bead mill, and a roll mill. It can be obtained by uniformly mixing and dispersing with a stirrer / kneader such as an attritor, sand mill, gate mixer, paint shaker, homogenizer, and self-revolving stirrer. Defoaming under vacuum or reduced pressure conditions is also preferably performed after mixing and dispersing, or in the process of mixing and dispersing.

The active energy ray-curable flat plate ink of the present invention preferably contains water of 0.1% by mass or more and less than 0.5% by mass as measured by the Karl Fischer method. Among the manufacturing steps of the ink, especially in the step of mixing and dispersing, moisture absorption of atmospheric humidity and evaporation of varnish moisture are likely to occur. By producing the varnish, the water content of the active energy ray-curable flat plate ink can be kept within the above range.

(Manufacturing method of printed matter)
The method for producing a printed matter using the active energy ray-curable lithographic ink of the present invention is as follows. First, the active energy ray-curable flat plate ink of the present invention is applied onto a substrate, and then the active energy ray is irradiated to cure the printed matter to obtain a printed matter having an ink curable film. Examples of the base material include, but are not limited to, art paper, coated paper, cast paper, synthetic paper, newspaper paper, aluminum vapor-deposited paper, metal, polypropylene, polyethylene terephthalate, and the like. The method of applying the active energy ray-curable flat plate ink of the present invention onto the substrate includes a step of applying the active energy ray-curable flat plate ink to a printing apparatus and a step of transferring the active energy ray-curable flat plate ink onto the substrate, and specifically. It can be applied onto the substrate by well-known methods such as flexographic printing, offset printing, gravure printing, screen printing, and bar coater. Of these, the lithographic printing method is preferable. There are two methods for lithographic printing, one with water and the other without water, but either method can be used. The thickness of the ink curing film applied on the substrate is preferably 0.1 to 50 μm.

Next, the ink coating film on the printed matter is cured by irradiating with active energy rays. As the active energy ray, any one having the excitation energy required for the curing reaction can be used, but for example, ultraviolet rays and electron beams are preferably used. When curing with an electron beam, an electron beam device having an energy ray of 100 to 500 eV is preferably used. When curing by ultraviolet rays, an ultraviolet irradiation device such as a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or an LED is preferably used. For example, when a metal halide lamp is used, it is conveyed by a conveyor by a lamp having an illuminance of 80 to 150 W / cm. Curing at a speed of 50 to 150 m / min is preferable from the viewpoint of productivity.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited thereto.

(1) Resin production In a reaction vessel equipped with a stirrer, a reflux cooling tube, a thermometer and a nitrogen gas introduction tube, 200 parts by mass of propylene glycol monomethyl ether acetate (hereinafter, PGMEA), 20 parts by mass of ethyl acrylate, and butyl acrylate as a solvent. 16 parts by mass, 30 parts by mass of methyl methacrylate and 34 parts by mass of acrylic acid were charged, and 5 parts by mass of 2,2'-azobis (2-methylbutyronitrile) (hereinafter, ABN-E) was added as a polymerization initiator. , 120 ° C., 1.5 hours reflux and stirring was carried out by dropping polymerization reaction, and the temperature was kept warm for 1 hour. Then, the temperature was raised to 160 ° C. and the solvent was distilled off while continuing stirring at normal pressure, then the pressure was reduced to 50 mHg or less at the same temperature, the solvent was completely distilled off, and the weight average molecular weight (hereinafter, Mw) was 20. A resin 1 having an acid value of 000 and an acid value of 200 mgKOH / g was obtained. The results are shown in Table 1. The weight average molecular weight of the resin is a value measured by GPC. GPC is HLC-8220 (manufactured by Tosoh Co., Ltd.), columns are TSKgel SuperHM-H (manufactured by Tosoh Co., Ltd.), TSKgel SuperHM-H (manufactured by Tosoh Co., Ltd.), TSKgel SuperH2000 (manufactured by Tosoh Co., Ltd.) in that order. The one linked with the above was used, tetrahydrofuran was used as a mobile phase, and RI detection was measured using the RI detector built in the GPC. A calibration curve was prepared using a polystyrene standard material, and the weight average molecular weight of the resin was calculated. The measurement sample is diluted with tetrahydrofuran so that the resin concentration becomes 0.25% by mass, and the diluted solution is dissolved by stirring with a mix rotor (MIX-ROTAR VMR-5, manufactured by AS ONE Co., Ltd.) at 100 rpm for 5 minutes. The mixture was obtained by filtering with a 0.2 μm filter (Z227536-100EA, manufactured by SIGMA). The measurement conditions were a driving amount of 10 μL, an analysis time of 30 minutes, a flow rate of 0.4 mL / min, and a column temperature of 40 degrees.

Description of abbreviations in Table 1, Table 2-1 and Table 2-2 PGMEA: Propylene Glycol Monomethyl Ether Acetate ST: Styrene EA: Ethyl Acrylate BA; Butyl Acrylate
MMA: Methyl methacrylate
AA: ABN-E acrylate; 2,2'-azobis (2-methylbutyronitrile)
TBHQ: tert-Butylhydroquinone TEMPOL: 4-Hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

<Manufacturing of resins 2-4>
Resins 2 to 4 were obtained in the same manner as in Resin 1, except that Resin 1 was changed as shown in Table 1. Table 1 shows the resin composition and the resin physical characteristics.

<Measurement method of ethylene oxide chain of ethylene unsaturated compound>
The ethylene unsaturated compound was subjected to LC / MS measurement using the LC system "Ultimate3000" (manufactured by Thermo Fisher Scientific) and the MS system "Orbitrap Fusion" (manufactured by Thermo Fisher Scientific) to obtain a mass spectrum and a product spectrum. The measurement conditions were column: Cadenza CD-C18 2.0 × 150 mm, 3 μm (manufactured by Imtakt), mobile phase: 10 mmol / L ammonium acetate aqueous solution and acetonitrile / tetrahydrone = 7: 3, flow rate: 0.3 mL / min, column. Temperature: 45 ° C., injection amount: 3 μm, ionization: ESI method, MS detection: full scan (m / z 200 to 3000), cation detection. The structure of the ethylenically unsaturated compound was identified from the obtained mass spectrum and product spectrum, and the number of ethylene oxide chains in one molecule was calculated.

<Measurement method of acid value>
The acid value of the resin was measured by a neutralization titration method according to the test method Section 3.1 of JIS K 0070: 1992. First, 1.0 g of the resin was weighed in an Erlenmeyer flask, 100 ml of acetone and a few drops of a phenolphthalein solution as an indicator were added, and the sample was shaken sufficiently on a water bath until the sample was completely dissolved. Next, titration was performed with a 0.1 mol / l potassium hydroxide ethanol solution, and the end point was when the indicator had a light red color for 30 seconds. Then, the acid value was calculated by the following formula.

A = [B × f × 5.611 / S]
(A: Acid value (mgKOH / g), B: Amount of 0.1 mol / l potassium hydroxide ethanol solution (ml) used for titration, f: Factor of 0.1 mol / l potassium hydroxide ethanol solution (concentration correction) Coefficient), S: Mass of sample (g)).

<Evaluation method for varnish and ink>
(1) Evaluation of appearance of varnish The appearance of the varnish left at 25 ° C. for 10 hours after production was visually observed and judged according to the following criteria.

◯: Transparent without cloudiness ×: Transparent with cloudiness or varnish is transparent but phase-separated (2) Varnish viscosity measurement Using a cone plate type rotary viscometer (MCR102, manufactured by Anton Pearl) , 25 ° C., 0.5 rpm.

(3) Varnish moisture content measurement The varnish moisture content is measured by the Karl Fischer method with the moisture vaporizer EV-2000 (manufactured by Hiranuma Sangyo Co., Ltd.) attached to the trace moisture measuring device AQ2200A (manufactured by Hiranuma Sangyo Co., Ltd.). It was measured.

(4) Measurement of metal salt content Measurement was performed using an ICP emission spectrophotometer (PS3520- VDDII manufactured by Hitachi High-Tech Science Co., Ltd.).

(5) Evaluation of storage stability of varnish 40 g of varnish was weighed into a 50 cc screw tube, the lid was closed, and then the mixture was allowed to stand in an oven (“DP22” (manufactured by Yamato Scientific Co., Ltd.)) at 90 ° C. for 10 hours. The appearance was visually observed every time, and the time until cloudiness, gelation, or phase separation was observed was defined as the stabilization time, and the storage stability was evaluated according to the following criteria.

A: Stable time is 200 hours or more (extremely good)
B: Stable time is 100 hours or more and less than 200 hours (slightly good)
C: Stabilization time is 50 hours or more and less than 100 hours (good)
D: Less than 50 hours (defective).

(6) Ink moisture content measurement The ink moisture content is measured by the Karl Fischer method with the moisture vaporizer EV-2000 (manufactured by Hiranuma Sangyo Co., Ltd.) attached to the trace moisture measuring device AQ2200A (manufactured by Hiranuma Sangyo Co., Ltd.). It was measured.

(7) Ink curability evaluation A waterless lithographic printing plate (TAC-VG5, manufactured by Toray Co., Ltd.) was mounted on an offset printing machine (Oliver 266EPZ, manufactured by Sakurai Graphic System Co., Ltd.), and each ink produced was used. Then, print on 5000 sheets of coated paper, and use an ultraviolet irradiation device (120 W / cm, 1 ultra-high pressure metahara lamp) manufactured by USHIO Co., Ltd. to irradiate the belt conveyor speed with ultraviolet rays at 80 m / min to apply ink. It was cured to obtain a printed matter. With one sheet of coated paper overlaid on the obtained printed matter and a weight of 200 g placed on it, the coated paper is moved 10 cm to the side at a speed of 3 cm per second to count the number of scratches on the printed surface. bottom. Curability was evaluated according to the following criteria.

A: The number of scratches is 0 B: The number of scratches is 1 to 3 C: The number of scratches is 4 to 10 D: The number of scratches is 10 or more.

(8) Evaluation of misting resistance Spread 1.3 mL of ink on an incometer (manufactured by Tester Sangyo Co., Ltd.), rotate it at a roll temperature of 38 ° C. and 400 rpm for 1 minute, and apply the ink on white paper placed directly under the roll. The degree of scattering was arbitrarily measured at 5 points using a Gretag color difference meter (SpectroEye manufactured by GretagMacbeth), the average value was calculated, and the blank value (measured value of white paper measured in advance by the same method) was subtracted. It was evaluated by determining (ΔK). Misting resistance was evaluated according to the following criteria.

A: Reflection density is 0.01 or less (extremely good)
B: Reflection density is 0.02 or more and less than 0.05 (good)
C: Reflection density is 0.05 or more (defective).

(9) Evaluation of Ground Stain Resistance The black density in the non-image area of the printed matter when the solid black density of the printed matter is 2.0 is determined by using a reflection densitometer (SpectroEye, manufactured by GretagMacbeth) to obtain a print density of 25. The measurement was carried out under the conditions of ° C. and 30 ° C., and the ground stain resistance was evaluated according to the following criteria.

A: Reflection density is 0.05 or less (very good ground stain)
B: Reflection density is 0.06 or more and less than 0.10 (good ground stain resistance)
C: Reflection density is 0.10 or more (poor ground stain resistance).

[Example 1]
Pentaerythritol tetraacrylate ethylene oxide adduct "Miramer" (registered trademark) M4004 (manufactured by MIWON) 51.0 parts by mass, trimethylpropane triacrylate ethylene oxide adduct "DOUBLEMER" (registered trademark) TMP15EOTA (manufactured by DOUBLE BOND CHEMICAL) 19.8 mass 0.2 parts by mass of the polymerization inhibitor TBHQ (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a container and stirred at 80 ° C. for 1 hour, then 28 parts by mass of resin 1 was added to 100 ° C. and 5 parts. After stirring and dissolving under the condition of time, the mixture was cooled to 80 ° C., 1.0 part by mass of water was added, and the mixture was stirred for 1 hour. Then, it was cooled to room temperature to obtain a varnish for active energy ray-curable lithographic ink. The results of evaluating the physical characteristics of the varnish are shown in Table 2-1. Furthermore, as a result of evaluating the storage stability of the varnish, the stabilization time was 300 hours, and extremely good results were obtained.

Next, the ink was prepared by the following method. 50 parts by mass of the varnish, 19 parts by mass of carbon black "MOGUL" (registered trademark) E (manufactured by CABOT), 4 parts by mass of photopolymerization initiator "Irgacure" (registered trademark) 907 (manufactured by BASF), photopolymerization initiator "Irgacure" "(Registered trademark) TPO-L (manufactured by BASF) 6 parts by mass, sensitizer diethylaminobenzophenone (manufactured by Tokyo Kasei Co., Ltd.) 5 parts by mass, ethylenically unsaturated compound" Miramer "(registered trademark) M4004 (manufactured by MIWON) 11 parts by mass, extender pigment "Micro Ace" (registered trademark) P-3 (manufactured by Nippon Tarku Co., Ltd.) 2 parts by mass, pigment dispersant "Disparon" (registered trademark) DA-325 (manufactured by Kusumoto Kasei Co., Ltd.) Weigh 2 parts by mass and 1.0 part by mass of wax KTL-4N (manufactured by Kitamura Co., Ltd.), and use a three-roll mill "EXAKT" (registered trademark) M-80S (manufactured by EXAKT) to set the roller gap scale to 1. , The scale of the roll rotation speed was set to 500 rpm, and the mixture was kneaded four times to obtain an active energy ray-curable flat plate ink. When the printability of the ink was evaluated, the curability was a good result with 0 scratches, the misting resistance was poor with a reflection density of 0.10, and the ground stain resistance was a reflection density of 25 ° C. In the case of, 0.01 was good, and in the case of 30 ° C., 0.01 was good.

[Examples 2 to 4]
The same operations as in Example 1 were carried out except that the resin was changed in the composition shown in Table 2-1 to obtain an active energy ray-curable flat plate ink varnish and an active energy ray-curable flat plate ink. Table 2-1 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnishes for active energy ray-curable lithographic inks of Examples 2, 3 and 4 all had extremely good storage stability. The active energy ray-curable lithographic inks of Examples 2, 3 and 4 all had good curability in A, but in Examples 2 and 3, the misting resistance was good, and Examples showed. The misting resistance of No. 4 was extremely good.

[Examples 5 to 8]
In the composition shown in Table 2-1, the same operation as in Example 1 was carried out except that the ratio of the ethylenically unsaturated compound was changed to obtain a varnish for active energy ray-curable flat plate ink and an active energy ray-curable flat plate ink. rice field. Table 2-1 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnishes for active energy ray-curable lithographic inks of Examples 5 and 6 had extremely good storage stability, but the results were slightly good in Example 7, and in Example 8, the results were slightly good. It was a good result. The active energy ray-curable lithographic inks of Examples 7 and 8 had good curability at A, but curability was B in Example 5 and C in Example 6. ..

[Example 9]
The same operation as in Example 1 was carried out except that the resin and the ethylenically unsaturated compound were changed in the compositions shown in Table 2-1 to obtain an active energy ray-curable slab ink varnish and an active energy ray-curable slab ink. rice field. As a result of component fractionation and NMR analysis of the ethylenically unsaturated compound "DOUBLEMER" (registered trademark) PET5E04A (manufactured by DOUBLE BOND CHEMICAL) used in Example 9 by gel permeation chromatography (GPC), a penta with 9 ethylene oxide chains was used. It contained 72% of the erythritol tetraacrylate ethylene oxide adduct and 28% of the pentaerythritol tetraacrylate ethylene oxide adduct of the ethylene oxide chain 12. Table 2-1 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink had extremely good storage stability. Further, the active energy ray-curable lithographic ink had good curability in A and extremely good misting resistance and ground stain resistance in A.

[Examples 10 to 11]
In the composition shown in Table 2-1 the same operation as in Example 1 was carried out except that the resin, the amount of water added and the ratio of the ethylenically unsaturated compound were changed, and the varnish for the active energy ray-curable flat plate ink and the active energy ray. A curable slab ink was obtained. Table 2-1 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink of Example 10 had extremely good storage stability, but was slightly good in Example 11.

[Example 12]
A varnish for active energy ray-curable flat plate ink and an active energy ray-curable flat plate ink were obtained in the same manner as in Example 1 except that the resin and the polymerization inhibitor were changed in the compositions shown in Table 2-2. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink had extremely good storage stability. Further, the active energy ray-curable lithographic ink had good curability in A and extremely good misting resistance and ground stain resistance in A.

[Examples 13 to 15]
Varnish for active energy ray-curable flat plate ink by the same operation as in Example 1 except that the composition shown in Table 2-2 was newly added with a resin and a metal salt and the ratio of the ethylenically unsaturated compound was changed. And an active energy ray-curable flat plate ink was obtained. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink had extremely good storage stability. Further, the active energy ray-curable lithographic ink had good curability in A and extremely good misting resistance and ground stain resistance in A.

[Examples 16 to 18]
In the composition shown in Table 2-2, the same operation as in Example 1 was performed except that the resin, the amount of water added, and the ratio of the ethylenically unsaturated compound were changed. A curable slab ink was obtained. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnishes for active energy ray-curable lithographic inks of Examples 16 to 18 had extremely good storage stability.

[Comparative Example 1]
In the composition shown in Table 2-2, the same operation as in Example 1 was carried out except that the ethylenically unsaturated compound was changed and water was not added, and the varnish for active energy ray-curable flat plate ink and active energy ray-cured. A mold plate ink was obtained. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink had a cloudy appearance and poor storage stability. Further, the active energy ray-curable lithographic ink had a poor curability at C and a poor misting resistance at C.

[Comparative Example 2]
In the composition shown in Table 2-2, the same operation as in Example 1 was carried out except that the amount of the ethylenically unsaturated compound added was changed and water was not added. An energy ray-curable flat plate ink was obtained. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink had a good appearance, but had poor storage stability. Further, the active energy ray-curable lithographic ink had a good curability in A and a poor misting resistance in C.

[Comparative Example 3]
In the composition shown in Table 2-2, the same operation as in Example 1 was carried out except that the amount of the ethylenically unsaturated compound added and the amount of water added were changed, and the varnish for active energy ray-curable flat plate ink and the active energy ray-cured A mold plate ink was obtained. Table 2-2 shows the results of varnish physical property evaluation, storage stability evaluation, and ink printability evaluation. The varnish for active energy ray-curable lithographic ink was poor in appearance due to phase separation, and also in storage stability due to phase separation. Further, the active energy ray-curable lithographic ink was poor in curability at C, poor in misting resistance at C, and poor at ground stain resistance at C.

Claims (10)

It contains (1) an acrylic resin having an acid value of 100 mgKOH / g or more and 250 mgKOH / g or less and (2) at least two kinds of ethylenically unsaturated compounds having an ethylene oxide group, and the ethylenically unsaturated compound is as follows (A). ) And (B);
(A) A (meth) acrylate compound having 4 or more and less than 10 ethylene oxide groups in one molecule (B) A resin composition which is a (meth) acrylate compound having 10 or more and less than 20 ethylene oxide groups in one molecule. A varnish for active energy ray-curable flat plate ink, characterized in that the moisture content value when the composition is measured by the curl Fisher method is 0.2% by mass or more and less than 5.0% by mass. Of the (2) ethylenically unsaturated compounds having an ethylene oxide group, the ratio of the (meth) acrylate compound (A) to the total content of the (meth) acrylate compounds (A) and (B) is 50% or more and 95%. The varnish for active energy ray-curable flat plate ink according to claim 1, which is less than. Of the (2) ethylenically unsaturated compounds having an ethylene oxide group, the ratio of the (meth) acrylate compound (A) to the total content of the (meth) acrylate compounds (A) and (B) is 60% or more and 80%. The varnish for active energy ray-curable flat plate ink according to claim 1 or 2, which is less than. (2) The varnish for active energy ray-curable flat plate ink according to any one of claims 1 to 3, wherein the ethylenically unsaturated compound having an ethylene oxide group is a pentaerythritol tetra (meth) acrylate ethylene oxide adduct. The varnish for active energy ray-curable flat plate ink according to any one of claims 1 to 4, wherein the acid value of the acrylic resin is 190 mgKOH / g or more and 220 mgKOH / g or less. The varnish for active energy ray-curable flat plate ink according to any one of claims 1 to 5, wherein the acrylic resin contains a styrene skeleton structure and a (meth) acrylic acid alkyl ester structure. The active energy ray-curable slab ink according to any one of claims 1 to 6, wherein the varnish for the active energy ray-curable slab ink contains any one or more compounds selected from a nitroso compound and a polyfunctional amine compound. Varnish for. The active energy ray-curable slab ink according to any one of claims 1 to 7, wherein the varnish for active energy ray-curable slab ink contains at least one selected from an alkali metal salt and an alkaline earth metal salt. Varnish for. An active energy ray-curable flat plate ink containing the varnish and pigment for the active energy ray-curable flat plate ink according to any one of claims 1 to 8. A method for producing a printed matter, which comprises a step of applying the active energy ray-curable flat plate ink according to claim 9 onto a substrate, and a step of irradiating the substrate with active energy rays after the application.