Resin for active energy ray-curable ink, composition for active energy ray-curable ink, ink composition and printed matter

Abstract

To provide a resin for active energy ray-curable ink which can impart high flowability to ink, and has high elasticity.SOLUTION: A resin for active energy ray-curable ink is polyester which contains at least acid-modified rosin, a monobasic acid having a cyclic structure and polyol having three or more hydroxyl groups in one molecule as reactive components, and has an acid value of more than 10 mgKOH / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable ink resin, an active energy ray-curable ink composition, an ink composition, and a printed matter. [Background technology]

[0002] Active energy ray-curable inks are inks that can be instantly cured by active energy rays, and are environmentally friendly and easy to print, while producing high-quality printed matter. Because of these properties, active energy ray-curable inks are used in various printing methods, such as lithographic printing, letterpress printing, and intaglio printing.

[0003] Of the above printing methods, lithographic offset printing, which uses dampening water to transfer ink applied to a plate to an intermediate transfer medium such as a blanket, and then prints on the substrate, is widely used as a high-speed printing method for paper, plastic substrates, etc. Diallyl phthalate resin, urethane resin, etc. have been used as binder resins for active energy ray-curable inks for lithographic offset printing (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-193677 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-151848 Summary of the Invention [Problem to be solved by the invention]

[0005] Diallyl phthalate resin is widely used as an ink binder resin due to its excellent elasticity, but it has poor fluidity, which can cause printing problems such as "well-up," in which the ink does not transfer from the ink fountain to the ink fountain roll during printing, resulting in a decrease in print density. In addition, diallyl phthalate, the raw material for diallyl phthalate resin, is a substance of concern for its toxicity, which also poses problems from the perspective of work safety. Furthermore, urethane resins used as ink binder resins have the problem that they cause printing problems such as paper peeling due to the resin's poor elasticity.

[0006] The problem to be solved by the present invention is to provide an actinic ray-curable ink resin that can impart high fluidity to the ink and has high elasticity. Another object of the present invention is to provide an actinic ray-curable ink composition that can be used to prepare an ink composition having excellent flowability. Another problem to be solved by the present invention is to provide an ink composition having excellent flowability. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have discovered that a polyester having an acid value of more than 10 mgKOH / g, which contains as reaction components at least an acid-modified rosin, a monobasic acid having a cyclic structure, and a polyol having three or more hydroxyl groups in one molecule, has high elasticity and imparts high fluidity to the ink, and have completed the present invention.

[0008] That is, the present invention relates to the following active energy ray-curable ink resins, etc. 1. A resin for active energy ray-curable inks that is a polyester with an acid value of more than 10 mg KOH / g, and whose reactive components are at least acid-modified rosin, a monobasic acid with a cyclic structure, and a polyol with three or more hydroxyl groups in one molecule. 2. The active energy beam-curable ink resin according to 1, wherein the monobasic acid having a cyclic structure is one or more selected from the group consisting of benzoic acid, phenylacetic acid, cinnamic acid, mandelic acid, salicylic acid, atrolactic acid, anisic acid, toluic acid, ethylbenzoic acid, isopropylbenzoic acid, naphthoic acid, methylnaphthoic acid, anthronic acid, adamantic acid, hexahydrobenzoic acid, tetrahydrobenzoic acid, gum rosin, wood rosin, tall oil rosin, hydrogenated rosin, and disproportionated rosin. 3. The resin for an active energy ray-curable ink according to 1 or 2, wherein the acid-modified rosin is a maleic acid-modified rosin containing 50% by mass or more of maleopimaric acid. 4. The active energy ray-curable ink resin according to any one of 1 to 3, which has an acid value of more than 25 mgKOH / g. 5. The active energy ray-curable ink resin according to any one of 1 to 4, which has a hydroxyl value in the range of 1 to 200 mgKOH / g. 6. The active energy ray-curable ink resin according to any one of 1 to 5, which has a weight average molecular weight in the range of 3,000 to 400,000. 7. An active energy ray-curable ink composition comprising the active energy ray-curable ink resin according to any one of 1 to 6 and an active energy ray-curable monomer. 8. The active energy ray-curable ink composition according to 7, wherein the active energy ray-curable monomer is a polyfunctional (meth)acrylate monomer having three or more (meth)acrylate groups. 9. An ink composition containing the active energy ray-curable ink composition according to 7 or 8. A printed matter obtained by printing the ink composition according to 10.9 onto a substrate and curing it by irradiating it with active energy rays. [Effects of the Invention]

[0009] The present invention can provide an actinic ray-curable ink resin that can impart high fluidity to the ink and has high elasticity. The present invention provides an actinic ray-curable ink composition that can be used to prepare an ink composition with excellent flowability. The present invention can provide an ink composition having excellent flowability. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described below. The present invention is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope that does not impair the effects of the present invention. The compounds in this specification may be derived from fossil resources or biological resources (biomass).

[0011] [Active energy ray curable ink resin] The active energy ray-curable ink resin of the present invention (hereinafter sometimes simply referred to as "the ink resin of the present invention") is a polyester having, as at least reactive components, an acid-modified rosin, a monobasic acid having a cyclic structure, and a polyol having three or more hydroxyl groups in one molecule. The ink resin of the present invention has a short-chain, multi-branched structure, which ensures the elasticity of the resin itself, and by introducing a rosin skeleton and further increasing the acid value to more than 10 mgKOH / g, it is possible to improve affinity with pigments and give the ink fluidity.

[0012] In the present invention, the term "reactive component" means a component that constitutes a polyester, and does not include solvents, catalysts, etc. that do not constitute a polyester. The reactive components of the ink resin of the present invention will be described below.

[0013] Rosin is a naturally occurring component containing monocarboxylic acids having a carbon-carbon unsaturated double bond and a condensed ring, such as abietic acid, neoabietic acid, palustric acid, levopimaric acid, pimaric acid, and isopimaric acid. The acid-modified rosin, which is a reaction component, can be obtained by reacting one or more of the above monocarboxylic acids, or rosin itself, with an α,β-unsaturated carboxylic acid (Diels-Alder addition reaction).

[0014] Rosin includes natural rosins such as gum rosin, wood rosin, and tall oil rosin; stabilized rosins such as hydrogenated rosin and disproportionated rosin; and the like, but natural rosins such as gum rosin, wood rosin, and tall oil rosin are preferred. The rosin used may be one type alone or two or more types in combination.

[0015] Acid-modified rosin reacts with α,β-unsaturated carboxylic acid to reduce the carbon-carbon unsaturated double bonds in the rosin, improving its stability as an ink resin. In addition, the α,β-unsaturated carboxylic acid converts the monobasic acid rosin into a polybasic acid, improving the crosslink density of the ink resin and increasing its elastic modulus.

[0016] Examples of the α,β-unsaturated carboxylic acid that modifies rosin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid, isocrotonic acid, cinnamic acid, and 2,4-hexadienoic acid. The α,β-unsaturated carboxylic acid may be a derivative such as an acid anhydride, etc. The α,β-unsaturated carboxylic acid may be used alone or in combination of two or more kinds.

[0017] When rosin is reacted with an α,β-unsaturated carboxylic acid to obtain an acid-modified rosin, for example, 0.5 to 2.0 moles of the α,β-unsaturated carboxylic acid may be reacted with 1 mole of rosin.

[0018] The acid-modified rosin preferably contains maleopimaric acid, which is an acid generated by the reaction of levopimaric acid contained in rosin with maleic acid, and can be contained as a major component (50% by mass or more) in maleic acid-modified rosin obtained by reacting natural rosin with maleic acid. In the case of stabilized rosin such as hydrogenated rosin or disproportionated rosin, the amount of levopimaric acid, which has a carbon-carbon unsaturated double bond, is reduced, and even when reacted with maleic acid, maleopimaric acid does not become the main component.

[0019] The proportion of the acid-modified rosin in the reaction components is, for example, in the range of 5 to 90 mass%, preferably in the range of 10 to 80 mass%, more preferably in the range of 20 to 70 mass%, and even more preferably in the range of 30 to 60 mass%, relative to the total amount of the reaction components.

[0020] The "cyclic structure" in the monobasic acid having a cyclic structure may be either an aromatic ring or an aliphatic ring, or may be a heterocycle further containing a heteroatom (boron, nitrogen, sulfur, oxygen, or phosphorus) in the structure.

[0021] Specific examples of monobasic acids having a cyclic structure include benzoic acid, phenylacetic acid, cinnamic acid, mandelic acid, salicylic acid, atrolactic acid, anisic acid, toluic acid, ethylbenzoic acid, isopropylbenzoic acid, naphthoic acid, methylnaphthoic acid, anthronic acid, adamantic acid, hexahydrobenzoic acid, tetrahydrobenzoic acid, gum rosin, wood rosin, tall oil rosin, hydrogenated rosin, and disproportionated rosin. The monobasic acid having a cyclic structure may be a derivative such as an ester, etc. The monobasic acid having a cyclic structure may be used alone or in combination of two or more kinds.

[0022] The proportion of the monobasic acid having a cyclic structure in the reaction components is, for example, in the range of 5 to 60 mass%, preferably in the range of 5 to 50 mass%, more preferably in the range of 10 to 45 mass%, and even more preferably in the range of 15 to 40 mass%, relative to the total amount of the reaction components.

[0023] Specific examples of polyols having three or more hydroxyl groups in one molecule (hereinafter sometimes simply referred to as "polyols") include trihydric alcohols such as glycerin, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, trioxyisobutane, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2,3,4-pentanetriol, and 1,2,5-hexanetriol; tetrahydric alcohols such as pentaerythritol; and pentahydric or higher alcohols such as dipentaerythritol, glucose, sucrose, and sorbitol. The polyol may be a derivative such as an ester, etc. The polyol may be used alone or in combination of two or more kinds.

[0024] The proportion of polyol in the reaction components is, for example, in the range of 5 to 50 mass%, preferably in the range of 5 to 40 mass%, more preferably in the range of 5 to 30 mass%, and even more preferably in the range of 5 to 25 mass%, relative to the total amount of the reaction components.

[0025] The reactive components of the ink resin of the present invention may further contain a dialkylene glycol having 2 to 6 carbon atoms. The dialkylene glycol having 2 to 6 carbon atoms, which is a reaction component, is a diol having a structure in which two alkylene chains are linked by an ether bond (—O—), and specific examples include diethylene glycol and dipropylene glycol. The dialkylene glycol may be a derivative such as an ester, etc. The dialkylene glycol may be used alone or in combination of two or more kinds.

[0026] When a dialkylene glycol having 2 to 6 carbon atoms is used as a reaction component, the proportion of the dialkylene glycol having 2 to 6 carbon atoms is, for example, in the range of 5 to 30 mass %, and preferably in the range of 10 to 20 mass %, based on the total amount of the reaction components.

[0027] The ink resin of the present invention may be a polyester having as at least reaction components an acid-modified rosin, a monobasic acid having a cyclic structure, a polyol, and an optional dialkylene glycol, and the total proportion of the reaction components, the acid-modified rosin, the monobasic acid having a cyclic structure, the polyol, and the optional dialkylene glycol, is, for example, 90% by mass or more, 95% by mass or more, or 100% by mass.

[0028] The ink resin of the present invention is preferably a polyester having, as reaction components, an acid-modified rosin, a monobasic acid having a cyclic structure, and a polyol, or a polyester having, as reaction components, an acid-modified rosin, a monobasic acid having a cyclic structure, a polyol, and a dialkylene glycol having 2 to 6 carbon atoms.

[0029] The reaction components of the ink resin of the present invention may include components other than the acid-modified rosin, monobasic acid having a cyclic structure, polyol, and dialkylene glycol having 2 to 6 carbon atoms, as long as the effects of the present invention are not impaired. Examples of such other components include aliphatic diols other than dialkylene glycol having 2 to 6 carbon atoms, dibasic acids including α,β-unsaturated carboxylic acids, hydroxyl group (meth)acrylate compounds (such as HEMA), and monobasic acids other than monobasic acids having a cyclic structure, and these can be used in an amount of, for example, 0 to 10% by mass of the total amount of reaction components.

[0030] In order to give the ink resin of the present invention a short-chain, multi-branched structure, the reaction components preferably do not contain any dibasic acid other than the acid-modified rosin, and more preferably do not contain any aliphatic dicarboxylic acid.

[0031] The ink resin of the present invention has an acid value of more than 10 mgKOH / g. By making the acid value more than 10 mgKOH / g, the ink resin does not gel during production and the fluidity of the resulting ink can be ensured.

[0032] The acid value of the ink resin of the present invention is preferably more than 25 mgKOH / g, more preferably 26 mgKOH / g or more. There is no particular upper limit to the acid value of the ink resin of the present invention, but it is, for example, 60 mgKOH / g. The acid value of the ink resin of the present invention is confirmed by the method described in the examples.

[0033] The hydroxyl value of the polyester which is the ink resin of the present invention is preferably in the range of 1 to 200 mgKOH / g, more preferably in the range of 20 to 160 mgKOH / g, and even more preferably in the range of 40 to 130 mgKOH / g. The hydroxyl value of the polyester is confirmed by the method described in the examples.

[0034] The weight average molecular weight of the polyester that is the ink resin of the present invention is preferably in the range of 3,000 to 400,000, more preferably in the range of 5,000 to 350,000, and even more preferably in the range of 8,000 to 300,000. The weight average molecular weight is a value calculated as polystyrene based on gel permeation chromatography (GPC) measurement, and is measured by the method described in the Examples.

[0035] The properties of the polyester used as the ink resin of the present invention vary depending on the molecular weight, composition, etc., but it is usually a solid at room temperature.

[0036] The ink resin of the present invention may be any polyester containing at least an acid-modified rosin, a monobasic acid having a cyclic structure, and a polyol as reactive components, and may be, for example, two or more polyesters having different structures.

[0037] The polyester, which is the ink resin of the present invention, can be produced by reacting, for example, an acid-modified rosin, a monobasic acid having a cyclic structure, a polyol, and any dialkylene glycol having 2 to 6 carbon atoms all at once, with the hydroxyl group equivalent and the carboxyl group equivalent in the reaction components being the same or with the hydroxyl group equivalent being slightly in excess of the carboxyl group equivalent.

[0038] In producing the polyester, the reaction of the reaction components may be carried out as an esterification reaction, if necessary, in the presence of an esterification catalyst, for example, at a temperature range of 170 to 250° C. for 10 to 25 hours. The conditions of the esterification reaction, such as temperature and time, are not particularly limited and may be set appropriately.

[0039] Examples of the esterification catalyst include titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate; zinc-based catalysts such as zinc acetate; tin-based catalysts such as tin octoate and dibutyltin oxide; and organic sulfonic acid-based catalysts such as p-toluenesulfonic acid.

[0040] The amount of the esterification catalyst used may be set appropriately, but is usually in the range of 0.0001 to 0.1 part by mass per 100 parts by mass of the total amount of the reaction components.

[0041] [Active energy ray curable ink composition] The active energy ray-curable ink composition of the present invention (hereinafter sometimes simply referred to as "the ink composition of the present invention") contains the ink resin of the present invention. The ink resin of the present invention functions as a binder resin for the ink composition, and since the resin itself has high elasticity and high affinity with pigments, it can impart high fluidity to the ink composition.

[0042] The content of the ink resin of the present invention in the ink composition of the present invention is, for example, in the range of 1 to 50 mass % of the solid content of the ink composition, preferably in the range of 5 to 40 mass %, and more preferably in the range of 5 to 30 mass %. In the present invention, the term "solid content" refers to the total amount of components excluding the solvent from the ink composition of the present invention.

[0043] The ink composition of the present invention contains an active energy ray-curable monomer. The active energy ray-curable monomer functions as a diluent and is, for example, a monomer having a carbon-carbon unsaturated double bond and / or an oligomer having a carbon-carbon unsaturated double bond, and any monomer and / or oligomer known in the art for active energy ray-curable inks can be used.

[0044] The active energy ray-curable monomer is preferably a monofunctional (meth)acrylate and / or a polyfunctional (meth)acrylate.

[0045] Specific examples of monofunctional (meth)acrylates include ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isoamyl (meth)acrylate, isodecyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol ( (meth)acrylate, nonylphenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, nonylphenoxyethyl tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and the like.

[0046] Specific examples of bifunctional (meth)acrylates among the polyfunctional (meth)acrylates include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate; polyalkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dicyclopentadiene di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, dicyclopentadiene ... Examples of the acrylic acid ester include cyclopentanyl di(meth)acrylate, pentaerythritol di(meth)acrylate, bisphenol A ethylene oxide (EO) addition diacrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate or alkylene oxide-modified versions thereof, divinylbenzene, butanediol-1,4-divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, dipropylene glycol divinyl ether dipropylene glycol divinyl ether, hexanediol divinyl ether, triethylene glycol divinyl ether, phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, and phenyl glycidyl ether acrylate toluene diisocyanate urethane prepolymer.

[0047] Specific examples of the tri- or higher functional (meth)acrylate among the polyfunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, or alkylene oxide modified products thereof, and tri(meth)acrylates of alkylene oxide modified products of isocyanuric acid; ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, or Examples of the alkylene oxide-modified dipentaerythritol hexa(meth)acrylate include tetrafunctional (meth)acrylates such as these alkylene oxide-modified products; pentafunctional (meth)acrylates such as dipentaerythritol penta(meth)acrylate or alkylene oxide-modified products thereof; and hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, caprolactone-modified dipentaerythritol hexa(meth)acrylate or alkylene oxide-modified products thereof.

[0048] The active energy ray-curable monomers may be used alone or in combination of two or more.

[0049] Among active energy ray-curable monomers, tri- or higher functional (meth)acrylates, which are monomers having three or more (meth)acrylate groups, such as trimethylolpropane tri(meth)acrylate, alkylene oxide-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, are preferred because they can greatly contribute to improving curability and strength in printing applications on paper substrates such as fine paper, coated paper, art paper, construction paper, thin paper, and cardboard.

[0050] Polyfunctional (meth)acrylate monomers having three or more (meth)acrylate groups have high reactivity and therefore excellent curability, but tend to have poor fluidity. The ink resin of the present invention has an improved affinity with pigments by introducing a rosin skeleton and further increasing the acid value to more than 10 mgKOH / g, so the fluidity of the ink composition of the present invention can be ensured even when the above polyfunctional (meth)acrylate monomer is used.

[0051] When a trifunctional or higher functional (meth)acrylate is used as the active energy ray-curable monomer, the content of the trifunctional or higher functional (meth)acrylate is, for example, in the range of 15 to 75 mass % of the solid content of the ink composition, preferably in the range of 20 to 70 mass %, and more preferably in the range of 25 to 65 mass %. When the substrate is plastic, the content of the tri- or higher functional (meth)acrylate is preferably in the range of 0 to 50% by mass of the solid content of the ink composition.

[0052] When a trifunctional or higher functional (meth)acrylate is used as the active energy ray-curable monomer, the content of the trifunctional or higher functional (meth)acrylate is, for example, in the range of 20 to 210 parts by mass, preferably 30 to 200 parts by mass, and more preferably 40 to 190 parts by mass, relative to 100 parts by mass of the ink resin of the present invention.

[0053] The ink composition of the present invention can be prepared as an ink binder composition (varnish), for example, by dissolving the ink resin of the present invention in an active energy ray-curable monomer and adding an antioxidant, a polymerization inhibitor, etc. to the solution. These components will be explained below, but each component may be used alone or in combination of two or more.

[0054] Specific examples of the antioxidant include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, and phosphate-based antioxidants.

[0055] The content of the antioxidant may be appropriately set depending on the intended use, and may be, for example, in the range of 0.1 to 5% by mass of the solid content of the varnish.

[0056] Specific examples of polymerization inhibitors include (alkyl)phenols, hydroquinone, methoquinone, catechol, resorcinol, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydrazyl, phenothiazine, p-benzoquinone, nitrosobenzene, 2,5-di-tert-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cupferron, capferron, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, N-(3-oxyanilino-1,3-dimethylbutylidene)aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxime, cyclohexanone oxime, copper dimethyldithiocarbamate, and copper dibutyldithiocarbamate.

[0057] The content of the polymerization inhibitor may be appropriately set depending on the intended use, and may be, for example, in the range of 0.1 to 5% by mass of the solid content of the varnish.

[0058] [Ink composition] The ink composition of the present invention contains the active energy ray-curable ink composition of the present invention, and can be prepared by adding an extender pigment, a pigment, a photopolymerization initiator, a photosensitizer, a silicon-based additive, a wax, etc. to the active energy ray-curable ink composition (varnish) of the present invention. When preparing the ink composition, the ink resin, active energy ray curable monomer, antioxidant, polymerization inhibitor, etc. used in preparing the varnish may be additionally added. These components will be explained below, but each component may be used alone or in combination of two or more.

[0059] Specific examples of extender pigments include inorganic fine particles such as calcium carbonate, magnesium carbonate, kaolin clay, talc, bentonite, mica, barium sulfate, silica, aluminum hydroxide, titanium oxide, graphite, zinc oxide, lime carbonate powder, diatomaceous earth, alumina white, aluminum stearate, calcium stearate, baryte powder, abrasive powder, silicone, and glass beads. These inorganic fine particles not only have the effect of adjusting the fluidity of the ink, preventing misting, and preventing penetration into printing substrates such as paper, but also have the added effect of suppressing paper peeling problems that occur when printing under low temperature conditions such as winter or when printing at high speeds.

[0060] The content of the extender pigment may be appropriately set depending on the intended use, and may be, for example, in the range of 1 to 10% by mass, preferably 1 to 6% by mass, of the solid content of the ink composition.

[0061] Specific examples of pigments include inorganic pigments such as iron oxide and carbon black; and organic pigments such as quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments.

[0062] The content of the pigment may be appropriately set depending on the intended use, and may be, for example, in the range of 1 to 50 mass % of the solid content of the ink composition, and preferably in the range of 10 to 30 mass %.

[0063] Examples of the photopolymerization initiator include an α-aminoalkylphenone compound, an acylphosphine oxide compound, a benzophenone compound, a thioxanthone compound, a ketocoumarin compound, a hydroxyacetophenone compound, and a benzyl dimethyl ketal compound.

[0064] Specific examples of the α-aminoalkylphenone compound as a photopolymerization initiator include 2-(dimethylamino)-2-methyl-1-[4-(4-morpholinyl)phenyl]-3-phenyl-1-propanone, 1-butanone, 2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-2-(phenylmethyl)-,(2S)-, 2-(dimethylamino)-2-methyl-3-(4-methylphenyl)-1-[4-(4-morpholinyl)phenyl]-1-propanone, 2-(dimethylamino)-1-[4 -(4-morpholinyl)phenyl]-2-(phenylmethyl)-1-pentanone, 2-(dimethylamino)-2-[(4-ethylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-(dimethylamino)-2-[(4-hydroxyphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-[(4-butylphenyl)methyl]-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, 1-butanone,2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-2-[(4-propylphenyl)methyl]-, 2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-2-phenyl-1-butanone, 3-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-3-(phenylmethyl)-2-pentanone, 2-(dimethylamino)-2-ethyl-1-[4-(4-morpholinyl)phenyl]-4-phenyl-1-butanone, 3-(Dimethylamino)-1-[4-(4-morpholinyl)phenyl]-3-phenyl-2-butanone, 1-(4-mercaptophenyl)-2-methyl-2-(4-morpholinyl)-1-propanone, 1-[4-(ethylthio)phenyl]-2-methyl-2-(4-morpholinyl)-1-propanone, dimethyl[4-[2-methyl-2-(4-morpholinyl)-1-oxopropyl]phenyl]sulfonium, 2-methyl-1-[4-[(1-methylethyl) Thio]phenyl]-2-(4-morpholinyl)-1-propanone, Ethylmethyl[4-[2-methyl-2-(4-morpholinyl)-1-oxopropyl]phenyl]sulfonium, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morph Examples include 2-benzyl-2-dimethylamino-1-(4-piperidinylphenyl)-1-butanone, 1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, 1-(4-methoxyphenyl)-2-methyl-2-morpholin-4-yl-propan-1-one, polyethylene glycol (200) di(β-4[4-(2-dimethylamino-2-benzyl)butanonylphenyl]piperazinepropionate, etc.

[0065] Examples of the acylphosphine oxide compound that is a photopolymerization initiator include compounds represented by the following general formula (1).

[0066] [ka] (In the general formula (1), R 1 ~R 4 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Y 1 is an alkyl group having 1 to 6 carbon atoms or a group represented by the following general formula (2): Y 2 is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a (poly)alkoxyalkyl group (the alkoxyalkyl group portion is an alkoxyalkyl group having 2 to 12 carbon atoms), a phenyl group, or a group represented by the following general formula (3): Y 3 is a phenyl group or a group represented by the following general formula (2):

[0067] [ka] (In the general formulas (2) and (3), R 5 ~R 13 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 14 and R 15 are each independently an alkylene group or a (poly)oxyalkylene group having 1 to 6 carbon atoms (the alkylene group portion is an alkylene group having 1 to 6 carbon atoms), Y 11 is an alkyl group having 1 to 6 carbon atoms or a group represented by the general formula (2), Y 33 is a phenyl group or a group represented by the general formula (2), * indicates the bond position.)

[0068] R 1 ~R 13 Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0069] R 14and R 15 Examples of the alkylene group having 1 to 6 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group.

[0070] Among the acylphosphine oxide compounds represented by the general formula (1), R 1 , R 2 and R 4 is a methyl group, and R 3 and Y 1 is a hydrogen atom, and Y 2 is an ethyl group, and Y 3 is a phenyl group, ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate is preferred. Ethyl phenyl (2,4,6-trimethylbenzoyl) phosphinate is commercially available as TPO-L (CAS #84434-11-7, manufactured by SARTOMER).

[0071] Among the acylphosphine oxide compounds represented by the general formula (1), R 1 , R 2 and R 4 is a methyl group, and R 3 is a hydrogen atom, and Y 2 is a polyalkoxymethyl group having 2 carbon atoms, Y 3 is represented by the structural moiety represented by general formula (2), and R 6 , R 7 and R 9 is a methyl group, and R 5 and R 8 is a hydrogen atom is preferred. This compound is commercially available as Omnirad 820 (manufactured by IGM Resins BV).

[0072] Among the acylphosphine oxide compounds represented by the general formula (1), R 1 , R 2 and R 4 is a methyl group, and R 3 is a hydrogen atom, and Y 1is represented by the structural moiety represented by general formula (2), and R 5 ~R 9 is a hydrogen atom, and Y 2 is an ethyl group, and Y 3 is a phenyl group, ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate is preferred. Ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate is commercially available as SpeedCure XKm (CAS #1539267-56-5, manufactured by SARTOMER).

[0073] Among the acylphosphine oxide compounds represented by the general formula (1), R 1 , R 2 and R 4 is a methyl group, and R 3 and Y 1 is a hydrogen atom, and Y 3 is a phenyl group, and Y 2 is a group represented by general formula (3), and R 10 , R 11 and R 13 is a methyl group, and R 12 and Y 11 is a hydrogen atom, and Y 33 is a phenyl group, and R 14 and R 15 is a (poly)oxyalkylene group having 2 carbon atoms. This compound is commercially available as Omnipol TP (#CAS 1834525-17-5, manufactured by IGM Resins BV).

[0074] Benzophenone compounds that serve as photopolymerization initiators include 4,4'-dialkylaminobenzophenones (e.g., 4,4'-bis-(dimethylamino)benzophenone, 4,4'-bis-(diethylamino)benzophenone), 4-benzoyl-4'-methyldiphenyl sulfide, and 4-methylbenzophenone, and of these, 4,4'-bis-(diethylamino)benzophenone is preferred.

[0075] Examples of thioxanthone compounds that serve as photopolymerization initiators include 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-isopropylthioxanthone, 4-diisopropylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dichlorothioxanthone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthone-2-yloxy-N,N,N-trimethyl-1-propanamine hydrochloride, and the like. Of these, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-chlorothioxanthone, and 2-isopropylthioxanthone are preferred.

[0076] Examples of ketocoumarin compounds that are photopolymerization initiators include 3-benzoylcoumarin, 3-(4-methoxybenzoyl)coumarin, 3-benzoyl-7-methoxycoumarin, 3-(4-methoxybenzoyl)7-methoxy-3-coumarin, 3-acetyl-7-dimethylaminocoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3,3'-coumarinoketone, and 3,3'-bis(7-diethylaminocoumarin)ketone.

[0077] Examples of the hydroxyacetophenone compound that is a photopolymerization initiator include ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

[0078] An example of a benzyl dimethyl ketal compound that serves as a photopolymerization initiator is 2,2-dimethoxy-2-phenylacetophenone.

[0079] The content of the photopolymerization initiator may be appropriately set depending on the intended use, and may be, for example, in the range of 1 to 20 mass % of the solid content of the ink composition, and preferably in the range of 5 to 15 mass %.

[0080] Specific examples of photosensitizers include amine compounds such as aliphatic amines and aromatic amines, urea compounds such as o-tolylthiourea, and sulfur compounds such as sodium diethyldithiophosphate and s-benzylisothiuronium-p-toluenesulfonate.

[0081] The content of the photosensitizer may be appropriately set depending on the intended use, and may be, for example, in the range of 1 to 20 mass % of the solid content of the ink composition, and preferably in the range of 1 to 10 mass %.

[0082] Specific examples of silicon-based additives include polyorganosiloxanes having an alkyl group or a phenyl group, such as dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer, and amino-modified dimethylpolysiloxane copolymer, polydimethylsiloxanes having a polyether-modified acrylic group, and polydimethylsiloxanes having a polyester-modified acrylic group.

[0083] The silicon-based additive is added for the purpose of imparting slipperiness to the printed matter, and the content of the silicon-based additive may be appropriately set depending on the intended use.

[0084] Specific examples of waxes include paraffin wax, carnauba wax, beeswax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, polytetrafluoroethylene wax, and amide wax, as well as fatty acids having approximately 8 to 18 carbon atoms, such as coconut oil fatty acids and soybean oil fatty acids.

[0085] The wax is added for the purpose of improving the curability, and the content of the wax may be appropriately determined depending on the intended use.

[0086] In addition to the above, the ink composition of the present invention may contain known additives such as pigment dispersants, metal complexes (chelating agents), photoinitiator assistants, curing accelerators (cobalt naphthenate, etc.), fillers, thickeners, foaming agents, antioxidants (tocopherol, butylhydroxyanisole, dibutylhydroxytoluene, etc.), flame retardants, ultraviolet absorbers, and antibacterial agents.

[0087] The ink composition of the present invention can be used without a solvent, or an appropriate solvent may be used as needed. The solvent for the ink composition of the present invention is not particularly limited as long as it does not react with the above-mentioned components.

[0088] The ink composition of the present invention can be produced by a known method, for example, by using a milling, mixing or adjusting machine such as a kneader, a three-roll mill, an attritor, a sand mill or a gate mixer to mill the components of the ink composition of the present invention.

[0089] [Printing using ink composition] The ink composition of the present invention can be applied to a substrate by a known method, and then the resulting coating film is cured by irradiating it with active energy rays, thereby carrying out printing.

[0090] The substrate is not particularly limited, and examples thereof include uncoated paper (such as fine paper), coated paper (such as lightly coated paper, art paper, coated paper, lightweight coated paper, and cast coated paper), paperboard (such as white paperboard and cardboard), synthetic paper, aluminum-deposited paper, and plastic sheets.

[0091] The application method is not particularly limited, and known printing methods such as screen printing, offset printing, flexographic printing, and roll printing can be used.

[0092] Examples of sources of active energy rays include ultraviolet light emitted from germicidal lamps, ultraviolet fluorescent lamps, ultraviolet light-emitting diodes (UV-LEDs), carbon arcs, xenon lamps, high-pressure water for copying, medium- or high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, natural light, etc. Among these, ultraviolet light-emitting diodes (UV-LEDs) preferably have a peak wavelength in the range of 350 to 420 nm and an integrated light intensity of preferably 5 mJ / cm. 2 ~200mJ / cm 2 The range is.

[0093] The ink composition of the present invention can be used without limitation in any printing method, such as lithographic printing, letterpress printing, intaglio printing, stencil printing, etc. In particular, it can be suitably used in lithographic offset printing, which combines lithographic printing (lithographic printing using dampening water and waterless lithographic printing not using dampening water) with a method in which ink applied to the lithographic plate is transferred to an intermediate transfer body such as a blanket, and then transferred (offset) to a substrate.

[0094] Since the ink resin of the present invention has high fluidity, the ink can be supplied stably onto the printing plate, making it possible to produce printed matter of stable quality without causing printing problems such as "bubble-up." [Example]

[0095] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to the following examples.

[0096] In the examples of the present application, the acid value and hydroxyl value were evaluated by the following methods. [Acid value measurement method] Measurement was carried out according to the method of JIS K0070-1992. [Method for measuring hydroxyl value] Measurement was carried out according to the method of JIS K0070-1992.

[0097] In the examples of the present application, the number average molecular weight and weight average molecular weight of polyesters are values ​​calculated as polystyrene based on GPC measurement, and the measurement conditions are as follows. [GPC measurement conditions] Measurement equipment: Tosoh Corporation's high-speed GPC equipment "HLC-8420GPC" Column: Tosoh Corporation "TSKgel SuperMultiporeHZ-H" x 2 Detector: RI (differential refractometer) Data processing: Tosoh Corporation's "EcoSEC Data Analysis Version 1.07" Column temperature: 40℃ Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Measurement sample: 7.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran, and the resulting solution was filtered through a microfilter to prepare a measurement sample. Sample injection volume: 20 μl Standard material: "PStQuick MP-H" manufactured by Tosoh Corporation

[0098] In the examples of the present application, the content of acid-modified rosin (main component maleopimaric acid) is 13 The evaluation was carried out by C-NMR measurement under the following measurement conditions. [ 13 C-NMR measurement conditions] Measurement equipment: JEOL AL400 / ECA500 nuclear magnetic resonance spectrometer Accumulation: 400 times Measurement temperature: room temperature NNE mode Sample concentration: 30 wt% deuterated chloroform solution Relaxation reagent: Tris(2,4-pentanedionato)chromium(III)

[0099] (Synthesis Example 1: Preparation of Polyester Resin A1) 279.2 g of gum rosin and 85.0 g of maleic anhydride were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 180°C while stirring under a nitrogen stream. Heating was then continued at 180°C for 1 hour to obtain a maleic acid-modified rosin containing at least 50% by mass of maleopimaric acid. Heating was stopped, and 137.7 g of benzoic acid, 127.0 g of diethylene glycol, 70.8 g of pentaerythritol, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were charged into the flask, and the temperature was gradually increased to 250°C while stirring under a nitrogen stream. Heating was then continued at 250°C, and the generated water was continuously removed to obtain polyester resin A1 (acid value 27.3, hydroxyl value 56.6, weight average molecular weight 164,340).

[0100] (Synthesis Example 2: Preparation of Polyester Resin A2) 286.8 g of gum rosin and 87.3 g of maleic anhydride were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 180°C while stirring under a nitrogen stream. Heating was then continued at 180°C for 1 hour to obtain a maleic acid-modified rosin containing at least 50% by mass of maleopimaric acid. Heating was stopped, and 141.4 g of benzoic acid, 77.5 g of diethylene glycol, 106.7 g of pentaerythritol, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were charged into the flask, and the temperature was raised stepwise to 250°C while stirring under a nitrogen stream. Heating was then continued at 250°C, and the generated water was continuously removed to obtain polyester resin A2 (acid value 34.7, hydroxyl value 80.4, weight average molecular weight 243,360).

[0101] Synthesis Example 3: Preparation of Polyester Resin A3 316.1 g of gum rosin and 96.3 g of maleic anhydride were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 180°C while stirring under a nitrogen stream. Heating was then continued at 180°C for 1 hour to obtain a maleic acid-modified rosin containing at least 50% by mass of maleopimaric acid. Heating was stopped, and 131.9 g of benzoic acid, 155.5 g of glycerin, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were charged into the flask, and the temperature was raised stepwise to 250°C while stirring under a nitrogen stream. Heating was then continued at 250°C, and the generated water was continuously removed to obtain polyester resin A3 (acid value 30.7, hydroxyl value 121.4, weight average molecular weight 17,730).

[0102] (Comparative Synthesis Example 1: Preparation of Polyester Resin A1') 406.0 g of disproportionated rosin, 44.1 g of benzoic acid, 146.3 g of tetrahydrophthalic anhydride, 35.7 g of propylene glycol, 63.0 g of glycerin, 5.6 g of trimethylolpropane, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 230 ° C. while stirring under a nitrogen stream. Heating was then continued at 230 ° C., and the resulting water was continuously removed to obtain polyester resin A1' (acid value 13.2, hydroxyl value 28.9, weight average molecular weight 15,940).

[0103] Comparative Synthesis Example 2: Preparation of Polyester Resin A2' 160.7 g of gum rosin and 48.9 g of maleic anhydride were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 180°C while stirring under a nitrogen stream. Heating was then continued at 180°C for 1 hour to obtain a maleic acid-modified rosin containing at least 50% by mass of maleopimaric acid. Heating was stopped, and 232.1 g of terephthalic acid, 230.8 g of diethylene glycol, 27.2 g of pentaerythritol, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were charged into the flask, and the temperature was raised stepwise to 250°C while stirring under a nitrogen stream. Heating was then continued at 250°C, and the generated water was continuously removed to obtain polyester resin A2' (acid value 24.7, hydroxyl value 88.0, weight average molecular weight 109,180).

[0104] Comparative Synthesis Example 3: Preparation of Polyester Resin A3' 269.3 g of gum rosin and 82.0 g of maleic anhydride were placed in a 1-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was heated stepwise to 180°C while stirring under a nitrogen stream. Heating was then continued at 180°C for 1 hour to obtain a maleic acid-modified rosin containing at least 50% by mass of maleopimaric acid. Heating was stopped, and 191.6 g of benzoic acid, 156.8 g of pentaerythritol, and 0.35 g of tetraisopropyl titanate as an esterification catalyst were charged into the flask, and the temperature was raised stepwise to 250°C while stirring under a nitrogen stream. Heating was then continued at 250°C, and the generated water was continuously removed. When the acid value fell below 10, the resin gelled.

[0105] (Examples 1-6 and Comparative Examples 1-8: Preparation and Evaluation of Actinic Ray-Curable Inks) The binder resin and ethylene oxide-modified trimethylolpropane triacrylate (MIRAMER M3130 manufactured by MIWON) shown in Tables 1 and 2 were charged in the proportions shown in Tables 1 and 2 into a 1.0 liter four-neck flask equipped with a thermometer, stirrer, and reflux condenser, and the temperature was raised to 100°C while stirring under an air flow. After continuing stirring at 100°C for 1 hour, the mixture was filtered through an 80-mesh filter to prepare an active energy ray-curable varnish. It should be noted that polyester resin A3' was not used in the production of varnish because it gelled.

[0106] The prepared varnish and each component were blended in the proportions shown in Tables 1 and 2, stirred using a mixer (single-screw dissolver), and then milled using a three-roll mill to prepare an actinic ray-curable ink. The resulting printing ink was subjected to various evaluations.

[0107] [Table 1]

[0108] [Table 2]

[0109] In Tables 1 and 2, the components are as follows: Diallyl phthalate resin: Daiso DAP A (manufactured by Osaka Soda Co., Ltd.) Polyurethane acrylate resin: V-4910 (DIC Corporation) S-381 N1: Hydrocarbon wax from Shamrock Technologies High Filler #5000PJ: Talc powder (Matsumura Sangyo Co., Ltd.) MIRAMER M3130: Trimethylolpropane ethylene oxide modified triacrylate (manufactured by MIWON) MIRAMER M600: Dipentaerythritol hexaacrylate (manufactured by MIWON) Carbon Special Black 250: Carbon black pigment (manufactured by Evonik Japan Co., Ltd.) Fastgen Yellow: Azo pigment (DIC Corporation) Omnirad TPO: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM) Omnirad EMK: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM) Solspers 24000GR: Dispersant (manufactured by Lubrizol) 64X0008-2: Nitrosamine stabilizer (DIC Corporation) ESS-246: Polyurethane acrylate dispersant (DIC Corporation)

[0110] (Misting property) 1.35 ml of the prepared active energy ray-curable ink was applied to an incometer manufactured by Toyo Seiki, and coated paper (57.5 kg, A size, "OK Top Coat Plus" manufactured by Oji Paper Co., Ltd.) was placed at the bottom and rear of the machine, and the machine was rotated at 1200 rpm for 3 minutes. After that, misting was visually evaluated based on the amount of ink that had flown onto the paper, according to the following criteria. 5: Not flying at all. 4: They are flying, but few in number. 3: There are some errors, but the quality is still good enough to print. 2: There is a lot of flying 1: Significantly flying

[0111] (Paper peeling) Using an offset printing press (Komori Corporation's "Lithrone G40") equipped with an ultraviolet irradiation device (output 160W / cm, three lamps used, Eye Graphics' "water-cooled metal halide lamp"), the clearance between the ink fountain and fountain roller was adjusted to 2-3μm, and the solid density of the solid image area was uniformly adjusted to an ink density of 1.7 (measured with an X-Rite SpectroEye densitometer), and offset printing was carried out at a printing speed of 15,000 sheets per hour. Coated paper (57.5kg, A size, Oji Paper's "OK Topcoat Plus") was used for printing. The dampening water supplied to the plate surface was an aqueous solution made by mixing 98% by mass of tap water and 2% by mass of an etching solution ("Presarto-SU" manufactured by DIC Corporation). The degree of paper peeling on the printed matter was visually evaluated according to the following criteria. 5: No peeling of paper is observed on the printed matter. 4: There is slight peeling of the paper on the printed matter. 3: There is some peeling of the paper on the printed matter, but it does not affect the quality. 2: Paper peeling is observed on the printed material. 1: There is noticeable peeling of the printed paper.

[0112] (Ink fluidity) The fluidity of the prepared ink was measured using the spreadmeter method (parallel plate viscometer) in accordance with JIS K5101, 5701. Specifically, the ink sandwiched between two horizontally placed parallel plates was observed over time for its concentric spreading due to the weight of the loaded plates (115 grams), and the diameter of the ink spread after 60 seconds was taken as the diameter value (DM [mm]), and the ink printability was evaluated according to the following criteria. Inks with a DM of less than 27 mm are more likely to cause printability problems such as ink fountain running out on the printing press and poor ink transfer between the ink rollers. ○: DM 30mm or more △: DM27 or more to less than 30 nm ×: Less than 27mm DM

[0113] The results in Tables 1 and 2 show that inks using polyester A1, polyester A2, and polyester A3 all have excellent elasticity (misting resistance and paper peeling) and fluidity. On the other hand, inks using polyester A1', which does not use acid-modified rosin, and inks using polyester resin A2', which uses a dibasic acid with a cyclic structure (rather than a monobasic acid with a cyclic structure), do not achieve both elasticity and fluidity, and inks using known diallyl phthalate resin and polyurethane acrylate resin also do not achieve both elasticity and fluidity.

Claims

1. An active energy ray-curable ink resin which is a polyester having an acid value of more than 10 mgKOH / g and which contains as reaction components at least an acid-modified rosin, a monobasic acid having a cyclic structure, a polyol having three or more hydroxyl groups in one molecule, and a dialkylene glycol having 2 to 6 carbon atoms, the monobasic acid having a cyclic structure is at least one selected from the group consisting of benzoic acid, ethyl benzoic acid, isopropyl benzoic acid, gum rosin, wood rosin, tall oil rosin, and hydrogenated rosin; The active energy ray-curable ink resin has a ratio of the dialkylene glycol having 2 to 6 carbon atoms in the reaction components in the range of 5 to 30 mass %.

2. An active energy ray-curable ink resin which is a polyester having an acid value of more than 10 mgKOH / g and which contains as reaction components at least an acid-modified rosin, a monobasic acid having a cyclic structure, and a polyol having three or more hydroxyl groups in one molecule, the monobasic acid having a cyclic structure is at least one selected from benzoic acid, ethyl benzoic acid, isopropyl benzoic acid, gum rosin, wood rosin, tall oil rosin, and hydrogenated rosin; the proportion of the acid-modified rosin in the reaction components is in the range of 30 to 60 mass% of the total amount of the reaction components; the proportion of the monobasic acid having a cyclic structure in the reaction components is in the range of 15 to 40 mass% of the total amount of the reaction components, an active energy ray-curable ink resin, wherein the total proportion of the acid-modified rosin, the monobasic acid having a cyclic structure, and the polyol having three or more hydroxyl groups in one molecule in the reaction components is 95 mass% or more.

3. 2. The active energy ray-curable ink resin according to claim 1, wherein the total amount of the acid-modified rosin, the monobasic acid having a cyclic structure, the polyol having three or more hydroxyl groups in one molecule, and the dialkylene glycol having 2 to 6 carbon atoms in the reaction components is 95% by mass or more.

4. 3. The actinic ray-curable ink resin according to claim 1, wherein the acid-modified rosin is a maleic acid-modified rosin containing 50% by mass or more of maleopimaric acid.

5. 3. The active energy ray-curable ink resin according to claim 1, which has an acid value of more than 25 mg KOH / g.

6. 3. The active energy ray-curable ink resin according to claim 1, wherein the hydroxyl value is in the range of 1 to 200 mgKOH / g.

7. 3. The active energy ray-curable ink resin according to claim 1, wherein the weight average molecular weight is in the range of 3,000 to 400,000.

8. 3. An active energy ray-curable ink composition comprising the active energy ray-curable ink resin according to claim 1 or 2 and an active energy ray-curable monomer.

9. The active energy ray-curable ink composition according to claim 8 , wherein the active energy ray-curable monomer comprises a polyfunctional (meth)acrylate monomer having three or more (meth)acrylate groups.

10. An ink composition comprising the active energy ray-curable ink composition according to claim 8.

11. A printed matter obtained by printing the ink composition according to claim 10 onto a substrate and curing the ink composition by irradiating it with active energy rays.

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