Active energy ray-curable resin composition, method for producing same, and printed matter

Abstract

To provide active energy ray-curable ink which has curability due to active energy rays, and dissolves curability and ink bottle release trouble at the time of printing, and improves a dot gain of a printed matter.SOLUTION: An active energy ray-curable resin composition contains a resin (A) obtained by reacting a hydroxyl group-containing polyester resin, an isocyanate compound and a hydroxyl group-containing acrylic compound, and a multi-functional acrylic compound (B), in which the hydroxyl group-containing acrylic compound is a resin obtained by reaction under the conditions of an OH / COOH molar ratio of polyhydric alcohol containing trihydric or higher alcohol to a polybasic acid of 1.10 to 2.20, and an amount of trihydric or higher alcohol to the whole polyhydric alcohol of 13 mol% or more, a hydroxyl value of the hydroxyl group-containing polyester resin is 50 or more, and a weight average molecular weight of the hydroxyl group-containing polyester resin is 3,000 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel and useful active energy ray-curable resin composition and a production method thereof. More specifically, the present invention relates to an active energy ray-curable resin composition that has excellent curability and can be widely used as various coating materials such as printing inks. [Background technology]

[0002] In recent years, growing demand for shorter printing turnaround times and environmental friendliness has led to the widespread use of fast-drying, solvent-free actinic radiation-curable inks, replacing traditional oil-based inks. Actinic radiation-curable inks contain active-energy radiation-curable unsaturated compounds, such as acrylic ester compounds, as components. They instantly cure upon exposure to active energy rays, forming a tough film through three-dimensional crosslinking of the unsaturated compounds. Because they cure instantly, post-processing can be performed immediately after printing. Therefore, actinic radiation-curable inks are ideal for applications such as packaging printing and commercial form printing, where a strong film is required for improved productivity and design protection.

[0003] Examples of unsaturated compounds used in actinic radiation-curable inks include acrylic ester compounds obtained by reacting polyols with acrylic acid, and oligomers such as polyester acrylates and polyurethane acrylates. Further improvements in productivity are required, and in order to accelerate the curing rate, resins in which acrylic groups are introduced into high-molecular-weight resins with high Tg have also been investigated. For example, Patent Documents 1 to 3 disclose resins in which acrylic groups are introduced into polyester polyols via isocyanate compounds. In Patent Document 1, no trivalent or higher alcohols are used in the synthesis of polyester polyols. In Patent Document 2, the ratio of OH contained in the alcohol used to COOH contained in the monobasic acid and polybasic acid (OH / COOH) is less than 1.10. Furthermore, Patent Document 3 does not disclose a ratio of trivalent or higher alcohols of 13.0 mol% or more relative to the total amount of alcohol used. This limits the amount of acrylic groups introduced into the resin, so further introduction of acrylic groups to improve curing properties is required.

[0004] Furthermore, compared to oil-based inks, active energy ray-curable inks have poor ink fluidity, which can cause problems such as ink not being scraped off the ink fountain by the roller during printing (ink fountain run-off), and low dot gain in printed materials, resulting in reduced print reproducibility. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-286019 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-348516 [Patent Document 3] Japanese Patent Publication No. 2020-90603 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide an actinic ray-curable ink that has improved curability, eliminates ink fountain leakage problems during printing, and improves dot gain in printed matter, and to provide a resin composition for use in said ink. [Means for solving the problem]

[0007] The present inventors have discovered that an active energy ray-curable resin containing many acrylic groups can be obtained by reacting a polyester resin containing many hydroxyl groups, an isocyanate compound, and a hydroxyl group-containing acrylic compound, and that an active energy ray-curable resin composition containing such a resin can provide an ink or the like having excellent curability and fluidity, thereby completing the present invention.

[0008] That is, the first invention of the present invention is: a resin (A) obtained by reacting a hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3); and polyfunctional acrylic compound (B) An active energy ray-curable resin composition comprising: the hydroxyl group-containing polyester resin (a1) is a resin obtained by reacting a polyhydric alcohol containing a trihydric or higher alcohol with a polybasic acid in an OH / COOH molar ratio of 1.10 to 2.20, and the trihydric or higher alcohol is reacted in a proportion of 13 mol % or more relative to the total polyhydric alcohol; the hydroxyl value of the hydroxyl-containing polyester resin (a1) is 50 or more, The present invention relates to an active energy ray-curable resin composition, characterized in that the weight-average molecular weight of the hydroxyl group-containing polyester resin (a1) is 3,000 or more.

[0009] The second aspect of the present invention is The present invention relates to the active energy ray-curable resin composition according to the first invention, wherein the isocyanate compound (a2) is a diisocyanate compound having two isocyanate groups.

[0010] The third aspect of the present invention is The present invention relates to the active energy ray-curable resin composition according to either the first or second invention, which is an ink composition.

[0011] The fourth aspect of the present invention is The present invention relates to a method for producing an active energy ray-curable resin composition according to any one of the first to third aspects of the present invention, characterized in that a hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3) ​​are reacted in a polyfunctional acrylic compound (B) to obtain a resin (A).

[0012] The fifth aspect of the present invention is The present invention relates to a printed matter obtained by printing the active energy ray-curable resin composition according to any one of the first to third inventions onto a substrate. [Effects of the Invention]

[0013] The present invention provides an actinic ray-curable ink that has improved curability, eliminates ink fountain leakage problems during printing, and improves dot gain in printed matter, as well as a resin composition for use in the ink. The actinic ray-curable resin composition of the present invention can be used in a wide range of applications and is extremely useful industrially. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below, and various modifications are possible within the scope of the gist of the present invention.

[0015] The active energy rays in the present invention refer to the energy required to excite the starting material of the curing reaction from the ground state to the transition state, and the active energy rays in the present invention refer to ultraviolet rays and electron beams.

[0016] The active energy ray-curable resin composition of the present invention comprises a resin (A) and a polyfunctional acrylic compound (B). The resin (A) is obtained by reacting a hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3). The resin (A) of the present invention is a resin having a complex structure obtained by reacting a hydroxyl group-containing polyester, an isocyanate compound, and a hydroxyl group-containing acrylic compound, and since it is impossible or not practical to represent it by a general formula (structure), it will be described by its production method.

[0017] (Hydroxyl group-containing polyester resin (a1)) The hydroxyl-containing polyester resin (a1) used in the present invention is a resin obtained by reacting a polyhydric alcohol containing a trihydric or higher alcohol with a polybasic acid at an OH / COOH molar ratio of 1.10 to 2.20. Here, OH refers to the number of moles of hydroxyl groups in the polyhydric alcohol, and COOH refers to the number of moles of carboxyl groups that can theoretically react with the alcohol. For example, in the case of 1 mole of carboxylic dianhydride, the COOH is 2 moles.

[0018] By using a trihydric or higher alcohol and reacting the polyhydric alcohol with a polybasic acid at an OH / COOH molar ratio of 1.10 to 2.20, it is possible to introduce a large number of hydroxyl group terminals into the polyester resin (a1), which then allows for the introduction of a large number of active energy ray-curable acrylic groups in the subsequent reaction with the isocyanate compound (a2) and the hydroxyl group-containing acrylic compound (a3). To introduce sufficient hydroxyl groups, the trihydric or higher alcohol content is preferably 13 mol% or more, and more preferably 20 mol% to 50 mol%, based on the total polyhydric alcohol content. If it exceeds 50 mol%, gelation is likely to occur during the synthesis of the polyester resin (a1). However, by using a monobasic acid such as benzoic acid in combination, it is possible to use 50 mol% or more of the trihydric or higher alcohol based on the total polyhydric alcohol content.

[0019] The trihydric or higher polyhydric alcohol is not particularly limited, and examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerin, ditrimethylolpropane, sorbitan, sorbitol, dipentaerythritol, inositol, and tripentaerythritol.

[0020] As the polyhydric alcohol, a dihydric alcohol can also be used. The dihydric alcohol is not particularly limited, and examples thereof include linear alkylene dihydric alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, and 1 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol, 1,16-hexadecanediol, 1,2-hexadecanediol, etc. are branched alkylene dihydric alcohols. Examples of cyclic alkylene dihydric alcohols include 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-dimethylpentanediol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dimethylol octane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,4-diethyl-1,5-pentanediol. Examples of cyclic alkylene dihydric alcohols include 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cycloheptanediol, tricyclodecane dimethanol, and hydrogenated bisphenol A. , hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, etc., as well as polyether polyols and polyester polyols such as polyethylene glycol (n=2 to 20), polypropylene glycol (n=2 to 20), and polytetramethylene glycol (n=2 to 20).

[0021] The polybasic acid is not particularly limited, and examples thereof include aliphatic polybasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, dodecenylsuccinic acid, and alkenylsuccinic acids such as pentadecenylsuccinic acid; aromatic polybasic acids such as isophthalic acid, isophthalic acid, terephthalic acid, himic acid, 3-methylhimic acid, 4-methylhimic acid, trimellitic acid, pyromellitic acid, 1,8-naphthalic acid, and anhydrides thereof; and alicyclic polybasic acids such as 1,2,3,6-tetrahydrophthalic acid, 3-methyl-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, and 1,4-cyclohexanedicarboxylic acid, and anhydrides thereof.

[0022] In the reaction of the polyfunctional alcohol with the polybasic acid, a monohydric alcohol or a monobasic acid can also be used in combination. Examples of monohydric alcohols include n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-butyl alcohol, tert-butyl alcohol, n-pentyl alcohol, isopentyl alcohol, amyl alcohol, tert-pentyl alcohol, cyclohexyl alcohol, benzyl alcohol, and α-phenylethyl alcohol.

[0023] Examples of monobasic acids include benzoic acid, methylbenzoic acid, t-butylbenzoic acid, naphthoic acid, orthobenzoylbenzoic acid, propionic acid, butyric acid, α-methylbutyric acid, valeric acid, and cyclohexanecarboxylic acid.

[0024] Furthermore, hydroxy acids such as lactic acid and 12-hydroxystearic acid, and cyclic esters such as caprolactone can also be used in combination.

[0025] The hydroxyl-containing polyester resin (a1) can be easily obtained by heating the polyhydric alcohol and polybasic acid in a conventional manner to cause a dehydration condensation reaction. The polyhydric alcohol and polybasic acid are reacted at an OH / COOH molar ratio in the range of 1.10 to 2.20, preferably 1.10 to 1.50. If the OH / COOH molar ratio is less than 1.10, the number of terminal hydroxyl groups will be reduced, and if it exceeds 2.20, the molecular weight will be difficult to elongate, which is not preferred.

[0026] Although the condensation reaction proceeds without a catalyst, a catalyst such as sulfuric acid, paratoluenesulfonic acid, or methanesulfonic acid may be used. An appropriate solvent such as xylene can also be used as needed. The weight-average molecular weight of the polyester resin (a1) is preferably 3,000 to 100,000, and more preferably 5,000 to 20,000. A weight-average molecular weight of less than 3,000 tends to reduce the effect of improving curability, while a weight-average molecular weight of more than 100,000 is undesirable because the viscosity of the final active energy ray-curable resin composition tends to increase. Furthermore, the hydroxyl value of the polyester resin (a1) is preferably 50 or more; a hydroxyl value of less than 50 is undesirable because the reaction of the hydroxyl group-containing acrylic compound (a3) ​​via the isocyanate compound (a2) does not proceed sufficiently, reducing the effect of improving curability.

[0027] (Isocyanate compound (a2)) The isocyanate compound (a2) is not particularly limited, and examples thereof include tolylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, and methylene diisocyanate. Examples of suitable diisocyanates include 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer diisocyanate in which the carboxyl group of a dimer acid is converted to an isocyanate group. From the viewpoint of reaction control, a difunctional diisocyanate is preferred.

[0028] (Hydroxyl group-containing acrylic compound (a3)) The hydroxyl group-containing acrylic compound (a3) ​​is not particularly limited, and examples thereof include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, polyethylene glycol acrylate, caprolactone-modified 2-hydroxyethyl acrylates, glycerin acrylate, glycerin diacrylate, diglycerin diacrylate, diglycerin triacrylate, trimethylolpropane acrylate, trimethylolpropane diacrylate, ditrimethylolpropane diacrylate, ditrimethylolpropane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, and dipentaerythritol pentaacrylate.

[0029] (Resin (A)) The resin (A) is obtained by reacting the above-mentioned hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3). The reactions of the hydroxyl-containing polyester resin (a1), the isocyanate compound (a2), and the hydroxyl-containing acrylic compound (a3) ​​may be carried out simultaneously, or the isocyanate compound (a2) and the hydroxyl-containing acrylic compound (a3) ​​may be reacted in advance, followed by the reaction of the hydroxyl-containing polyester resin (a1). The hydroxyl-containing polyester resins (a1) may also be reacted with each other using the isocyanate compound (a2), which is preferred when used in inks requiring viscoelasticity. The molar ratio NCO / OH of the total hydroxyl groups in the polyester resin (a1) and the hydroxyl-containing acrylic compound (a3) ​​to the isocyanate groups in the isocyanate compound (a2) is preferably 1 or less. The reaction proceeds without a catalyst, but a catalyst can also be used. Usable catalysts include, for example, tertiary amine catalysts such as triethylamine and dimethylaniline, and metal catalysts such as tin and zinc. Furthermore, the reaction can be carried out in a solvent if necessary, but it can also be carried out in a polyfunctional acrylic compound (B) described below, which is preferable because it eliminates the steps of dissolving the resin (A) in the polyfunctional acrylic compound and removing the solvent.

[0030] (Polyfunctional acrylic compound (B)) The content of the polyfunctional acrylic compound (B) used in the present invention is 10 to 90% by weight, preferably 40 to 80% by weight, based on the total weight of the composition, and the content of the radical polymerization inhibitor is 0.01 to 5% by weight, preferably 0.1 to 1% by weight.

[0031] The polyfunctional acrylic compound (B) is not particularly limited, and examples thereof include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate (n=2 to 20), propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate (n=2 to 20), alkane (having 4 to 12 carbon atoms) glycol di(meth)acrylate, alkane (having 4 to 12 carbon atoms) glycol ethylene oxide adduct (2 to 20 moles) di(meth)acrylate, alkane (having 4 to 12 carbon atoms) glycol propylene ... Bifunctional acrylic compounds such as ethylene oxide adduct (2 to 20 mol) di(meth)acrylate, hydroxypivalyl hydroxypivalate di(meth)acrylate, tricyclodecane dimethylol di(meth)acrylate, bisphenol A ethylene oxide adduct (2 to 20 mol) di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, hydrogenated bisphenol A ethylene oxide adduct (2 to 20 mol) di(meth)acrylate, glycerin tri(meth)acrylate, glycerin ethylene oxide adduct ( trifunctional acrylic compounds such as glycerin propylene oxide adduct (3 to 30 mol) tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide adduct (3 to 30 mol) tri(meth)acrylate, trimethylolpropane propylene oxide adduct (3 to 30 mol) tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethylene oxide adduct (4 to 40 mol) tetra(meth)acrylate, tetra(meth)acrylate, pentaerythritol propylene oxide adduct (4 to 40 mol) tetra(meth)acrylate, diglycerin tetra(meth)acrylate, pentaerythritol ethylene oxide adduct (4 to 40 mol) tetra(meth)acrylate, pentaerythritol propylene oxide adduct (4 to 40 mol) tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ditrimethylolpropane ethylene oxide adduct (4 to 40 mol) tetra(meth)acrylate,Examples of the acrylic compound include tetrafunctional or higher acrylic compounds such as ditrimethylolpropane propylene oxide adduct (3 to 30 moles) tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol ethylene oxide adduct (6 to 60 moles) hexa(meth)acrylate, and dipentaerythritol propylene oxide adduct (6 to 60 moles) hexa(meth)acrylate, and mixtures thereof.

[0032] In the active energy ray-curable resin composition of the present invention, an active energy ray-curable compound other than the polyfunctional acrylic compound (B) or an additive such as a radical polymerization inhibitor can be appropriately selected depending on the required physical properties of the cured coating film. For example, a monofunctional acrylic compound, a vinyl compound, or an active energy ray-curable oligomer can be used. Examples of monofunctional acrylic compounds include 2-ethylhexyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate, 2-(2-vinyloxyethoxy)ethyl (meth)acrylate, and acryloylmorpholine. Examples of the vinyl compound include N-vinylpyrrolidone and divinylbenzene. Examples of the active energy ray-curable oligomer include polyester acrylate, polyurethane acrylate, and epoxy acrylate.

[0033] Examples of radical polymerization inhibitors include (alkyl)phenols, hydroquinone, 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, 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, and cyclohexanone oxime.

[0034] (Ink composition) Next, the use of the ink composition, which is one embodiment of the active energy ray-curable resin composition of the present invention, will be described. Hereinafter, the ink composition will also be referred to as an active energy ray-curable ink. The active energy ray curable ink of the present invention contains, based on the total weight of the ink, 0 to 30% by weight of pigment, 5 to 40% by weight of binder resin, 20 to 70% by weight of the monomer having a radical polymerizable double bond, 0.01 to 1% by weight of the radical polymerization inhibitor, a photopolymerization initiator, and The composition is adjusted to contain 1 to 20% by weight of a sensitizer and / or 0 to 10 parts by weight of other additives. Here, the resin (A) used in the present invention corresponds to a binder resin.

[0035] The active energy ray-curable ink composition is cured by, for example, light, which is an active energy ray. For the photo-curing method, a light source that emits ultraviolet light, such as a metal halide lamp, a high-pressure mercury lamp, or an LED, is generally used.

[0036] If the active energy ray-curable ink of the present invention does not contain a pigment as a colorant and is made transparent, it becomes an OP varnish, and if it contains the pigment described below, it becomes a color printing ink.

[0037] The pigments can be inorganic or organic pigments. Inorganic pigments include yellow lead, zinc yellow, iron blue, barium sulfate, cadmium red, titanium oxide, zinc white, red iron oxide, alumina white, calcium carbonate, ultramarine, carbon black, graphite, aluminum powder, and red iron oxide. Organic pigments include soluble azo pigments such as β-naphthol, β-oxynaphthoic acid, β-oxynaphthoic acid anilide, acetoacetic acid anilide, and pyrazolone, and insoluble azo pigments such as β-naphthol, β-oxynaphthoic acid anilide, acetoacetic acid anilide monoazo, acetoacetic acid anilide disazo, and pyrazolone. Various known and commonly used pigments can be used, including phthalocyanine pigments such as copper phthalocyanine blue, halogenated (chlorinated or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanine; polycyclic pigments and heterocyclic pigments such as quinacridones, dioxazines, threnes (pyranthrones, anthanthrones, indanthrones, anthrapyrimidines, flavanthrones, thioindigos, anthraquinones, perinones, and perylenes); isoindolinones; metal complexes; and quinophthalones.

[0038] The active energy ray-curable ink of the present invention may further contain a binder resin other than the resin (A) as required.

[0039] The content of the resin (A) used in the present invention is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, based on the total weight of the ink. If the content is less than 5 parts by weight, the effects of the present invention cannot be fully achieved, and if the content is more than 40 parts by weight, the viscosity of the ink becomes too high and it is not suitable for printing.

[0040] Examples of binder resins other than the resin (A) used in the present invention include diallyl orthophthalate resin, diallyl isophthalate resin, diallyl terephthalate resin, polyester resin, polyvinyl chloride, poly(meth)acrylic acid ester, epoxy resin, polyurethane resin, petroleum (based) resin, cellulose derivatives (e.g., ethyl cellulose, cellulose acetate, nitrocellulose), vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, polyamide resin, polyvinyl acetal resin, synthetic rubber such as butadiene-acrylonitrile copolymer, etc. One or more of these resins can be used.

[0041] The photopolymerization initiator includes a photocleavage type initiator and a hydrogen abstraction type polymerization initiator.

[0042] Photocleavable initiators include α-(dimethyl)aminoalkylphenone compounds and α-morpholinoalkylphenone compounds.

[0043] More specifically, examples of the α-(dimethyl)amino alkylphenone compound include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 or 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and examples of the α-morpholino alkylphenone compound include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one. These may be used alone or in combination of two or more.

[0044] Furthermore, examples of the hydrogen abstraction type polymerization initiator include dialkylbenzophenone compounds and thioxanthone compounds.

[0045] More specifically, examples of the dialkylaminobenzophenone compound include 4,4'-dialkylaminobenzophenones such as 4,4'-bis-(dimethylamino)benzophenone and 4,4'-bis-(diethylamino)benzophenone, and 4-benzoyl-4'-methyldiphenyl sulfide. The dialkylaminobenzophenone compound may be used alone or in combination of two or more types. Examples of thioxanthone compounds 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. These compounds may be used alone or in combination of two or more.

[0046] Sensitizers include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 2,3,4-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(1,3-acryloyl-1,4,7,10,13-pentaoxotridecyl)benzophenone, methyl-o-benzoylbenzoate, [4-(methylphenylthio)phenyl]phenylmethanone, (4-benzoylbenzyl)trimethylammonium chloride, 2-hydroxy- Examples include 2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-styrylpropan-1-one polymer, diethoxyacetophenone, dibutoxyacetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin normal butyl ether, etc. These may be used alone or in combination of two or more.

[0047] Furthermore, other additives may be used in the active energy ray-curable ink of the present invention, if necessary.

[0048] For example, the radical polymerization inhibitor can be exemplified as an additive that imparts storage stability to the ink.Furthermore, examples of additives that impart rub resistance, anti-blocking properties, smoothness, and anti-scratch properties include natural waxes such as carnauba wax, Japan wax, lanolin, montan wax, paraffin wax, and microcrystalline wax, and synthetic waxes such as Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, and silicone compounds.

[0049] In addition, additives such as ultraviolet absorbers, infrared absorbers, antibacterial agents, etc. may be added depending on the required performance.

[0050] The active energy ray-curable ink of the present invention may be produced by the same method as that for conventional active energy ray-curable inks. For example, the ink composition components, such as the pigment, the resin composition of the present invention, a monomer having a radically polymerizable double bond, a polymerization inhibitor, a photopolymerization initiator and a sensitizer, and other additives, are mixed at a temperature between room temperature and 100°C using a milling, mixing, and adjusting machine such as a kneader, a three-roll mill, an attritor, a sand mill, or a gate mixer.

[0051] Examples of printing methods include lithographic printing (normal lithographic printing using dampening water and waterless lithographic printing not using dampening water), letterpress printing, intaglio printing, and stencil printing, with lithographic printing being preferred.

[0052] The substrate for the printed matter is not particularly limited, and examples include printing on any material such as paper, plastic, stickers, labels, and metal, with printing on paper being preferred. [Example]

[0053] The present invention will be described in more detail below with reference to examples, but the following examples are not intended to limit the scope of the present invention. In the present invention, "parts" means "parts by weight" and "%" means "% by weight".

[0054] In the present invention, the weight-average molecular weight was measured using a gel permeation chromatography (HLC-8320) manufactured by Tosoh Corporation. A calibration curve was prepared using a standard polystyrene sample. Tetrahydrofuran was used as the eluent, and three TSKgel SuperHM-M columns (manufactured by Tosoh Corporation) were used. Measurements were performed at a flow rate of 0.6 ml / min, an injection volume of 10 μl, and a column temperature of 40°C. In the present invention, unless otherwise specified, "molecular weight" refers to the weight-average molecular weight. The hydroxyl value was determined by a conventional potassium hydroxide titration method.

[0055] (Synthesis Example 1) The raw materials, 10 parts of glycerin, 20 parts of ethylene glycol, and 53 parts of phthalic anhydride, were placed in a four-neck flask equipped with a stirrer, Dean-Stark tube, thermometer, and gas inlet tube, and heated to 220°C while stirring. The reaction was continued while removing the condensed water produced as the reaction progressed, and was terminated when the theoretical amount of dehydration was reached, yielding Polyester Resin 1 (molecular weight: 4200, hydroxyl value: 187 mg KOH / g).

[0056] (Synthesis Examples 2 to 25) Resins 2 to 25 were obtained in the same manner as in Synthesis Example 1, except that the raw materials were changed according to the compositions in Table 1.

[0057] The physical properties of the synthesized resin are also shown in Table 1.

[0058] [Table 1]

[0059] (Production Example 1) In a four-neck flask equipped with a stirrer, condenser, thermometer, and gas inlet tube, 7 parts of toluene-2,4-diisocyanate (isocyanate compound (a2)), 35 parts of dipentaerythritol pentaacrylate (hydroxyl group-containing acrylic compound (a3)), 17.8 parts of dipentaerythritol hexaacrylate (polyfunctional acrylic compound (B)) and 20 parts of ditrimethylolpropane tetraacrylate, and 0.2 parts of tertiary butylhydroquinone as a polymerization inhibitor were added and reacted for 5 hours at 100 ° C. with stirring. Next, 20 parts of Resin 1 (polyester resin (a1)) were added and further reacted for 5 hours at 110 ° C. to obtain Resin Composition 1.

[0060] (Examples 2 to 30) Resin compositions 2 to 30 were obtained in the same manner as in Production Example 1, except that the raw materials were changed according to the formulations in Table 2.

[0061] (Manufacturing Example 31) In a four-neck flask equipped with a stirrer, condenser, thermometer, and gas inlet tube, 25 parts of Resin 2 (polyester resin (a1)), 53.4 parts of dipentaerythritol hexaacrylate (polyfunctional acrylic compound (B)), 20 parts of ditrimethylolpropane tetraacrylate, and 0.2 parts of tertiary butylhydroquinone as a polymerization inhibitor were placed and dissolved with stirring at 100°C for 1 hour. Next, 1.4 parts of toluene-2,4-diisocyanate (isocyanate compound (a2)) was added, and the mixture was allowed to react at 110°C for 5 hours to obtain Resin Composition 31.

[0062] (Examples 32 and 33) Resin compositions 32 and 33 were obtained in the same manner as in Production Example 31, except that the raw materials were changed according to the formulations in Table 2.

[0063] (Manufacturing Example 34) In a four-neck flask equipped with a stirrer, a cooler, a thermometer, and a gas inlet tube, 30 parts of Resin 2, which is a polyester resin (a1), 49.8 parts of dipentaerythritol hexaacrylate, which is a polyfunctional acrylic compound (B), 20 parts of ditrimethylolpropane tetraacrylate, and 0.2 parts of tertiary butyl hydroquinone as a polymerization inhibitor were placed, and dissolved at 100 ° C for 1 hour while stirring to obtain Resin Composition 34.

[0064] [Table 2]

[0065] [Table 2]

[0066] (Examples 1 to 24, Comparative Examples 1 to 10) According to the compositions in Table 3, Samples of Examples 1 to 24 and Comparative Examples 1 to 10 were obtained by mixing Resin Compositions 1 to 34 and an initiator. UV-cured films of the obtained samples were prepared and evaluated by a MEK (methyl ethyl ketone) rubbing test, and the results are shown in Table 3 together.

[0067] <MEK Rubbing Test> For the MEK rubbing test, a sample for MEK rubbing was coated on a corona-treated PET substrate (A-PET sheet Novaclear A2012, thickness 0.25 mm, manufactured by Mitsubishi Chemical Corporation) using a RI tester (simple color development machine), and cured using a metal halide lamp (output: 96 W / cm, lamp distance: 10 cm, conveyor speed: 100 m / min, number of passes: 1). The UV-cured film was rubbed back and forth with a cotton swab soaked with MEK, and judged from the number of back-and-forth movements of the cotton swab when the UV-cured film was damaged. ◎ and ○ are at the practical level. (Evaluation Criteria) ◎: 100 times or more, ○: less than 100 times and 50 times or more, △: less than 50 times and 25 times or more, ×: less than 25 times

[0068] [Table 3]

[0069] Examples 1 to 24 show that the resin composition of the present invention is excellent in resistance to MEK rubbing.

[0070] (Examples 25 to 48, Comparative Examples 11 to 20) The actinic radiation-curable inks of Examples 25 to 48 and Comparative Examples 11 to 20 were obtained by milling in a three-roll mill according to the compositions in Table 4. The viscosity and fluidity of the obtained actinic radiation-curable ink compositions were measured, and the dot gain of the printed matter and ink fountain run-off on the printing press were investigated. The results are also shown in Table 4.

[0071] <Viscosity measurement method> The viscosity was measured using a viscoelasticity measuring device (HAAKE RheoStress6000) manufactured by ThermoFisherScientific Co., Ltd., under conditions of a measurement temperature of 25°C and a cone plate (diameter: 20 mm, tilt angle: 0.5°).

[0072] <Method of measuring liquidity> 2.1 ml of ink was placed on a metal plate with a hemispherical depression, left to stand for 2 minutes, then tilted at a 60-degree angle and the length of ink flowing over 10 minutes was measured and evaluated based on the following criteria. A higher value indicates less ink clumping and better fluidity. ◎ and ○ are practical levels. (Evaluation criteria) ◎: 100mm or more, ○: Less than 100mm to 75mm or more, △: Less than 75mm to 50mm or more, ×: Less than 50mm

[0073] <Method for evaluating dot gain in printed materials> Printing was carried out at a speed of 10,000 sheets per hour using an actual offset sheet-fed printing press, Lithrone L426 (Komori Corporation), and the amount of expansion (dot gain) of 50% dots on the plate surface in the printed material after 5,000 sheets had been printed was measured using a SpectroEye manufactured by GretagMacbeth. ○ indicates a practical level. (Evaluation criteria) ○: Dot gain 10% or more, △: Dot gain less than 10% 8% or more, ×: Dot gain less than 8%

[0074] <Ink fountain run-off evaluation method> Printing was carried out under the above printing conditions, and the occurrence of "ink fountain run-out," a problem in which ink is not scraped off by the ink supply roller in the ink fountain during printing, was observed. ◎ and ○ are at practical levels. (Evaluation criteria) ◎: Does not occur for 20 minutes or more, ○: Does not occur for 10 minutes or more but less than 20 minutes, △: Does not occur for 5 minutes or more but less than 10 minutes, ×: Occurs in less than 5 minutes

[0075] <Curability evaluation method> Curing property was measured by applying ink at 1g / m2 to PE coated paper using an RI tester (simple color development machine). 2 of The ink was applied in the appropriate amount, and cured using a metal halide lamp (manufactured by Eye Graphics Co., Ltd., output: 96 W / cm, lamp distance: 10 cm) at various conveyor speeds (80, 100, 120 m / min). The surface condition of the ink coating was evaluated by rubbing with a cotton cloth. ◎ and ○ indicate practical levels. (Evaluation criteria) ◎: No scratches at all, ○: Some scratches, △: Scratches, ×: No coating film

[0076] [Table 4]

[0077] [Table 4]

[0078] It was found that Examples 25 to 48 of the present invention were superior in curability and flowability to the inks of Comparative Examples 11 to 20, and that active energy ray-curable inks capable of eliminating problems during printing could be obtained. [Industrial Applicability]

[0079] The resin composition of the present invention can enhance the curing reactivity of the resin composition to active energy rays by reacting a large number of acrylic compounds with the hydroxyl group-containing polyester resin, and can form a film with a highly crosslinked structure after curing. Therefore, it is useful for various printing inks, paints, coating agents, photoresists, etc. in addition to the offset sheet-fed printing specifically described above.

Claims

1. A resin (A) obtained by reacting a hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3), and Polyfunctional acrylic compound (B) An active energy ray-curable resin composition comprising: the hydroxyl group-containing polyester resin (a1) is a resin obtained by reacting a polyhydric alcohol containing a trihydric or higher alcohol with a polybasic acid under conditions in which the OH / COOH molar ratio is 1.10 to 2.20 and the amount of the trihydric or higher alcohol relative to the total amount of the polyhydric alcohol is 13 mol% or more; the hydroxyl value of the hydroxyl-containing polyester resin (a1) is 50 or more, The weight average molecular weight of the hydroxyl group-containing polyester resin (a1) is 3,000 or more, An active energy ray-curable resin composition, characterized in that the hydroxyl group-containing acrylic compound (a3) ​​contains dipentaerythritol pentaacrylate or pentaerythritol triacrylate.

2. 2. The active energy ray-curable resin composition according to claim 1, wherein the isocyanate compound (a2) is a diisocyanate compound.

3. 3. The active energy ray-curable resin composition according to claim 1, which is an ink composition.

4. 4. A method for producing the active energy ray-curable resin composition according to claim 1, comprising a step of reacting a hydroxyl group-containing polyester resin (a1), an isocyanate compound (a2), and a hydroxyl group-containing acrylic compound (a3) ​​in a polyfunctional acrylic compound (B) to obtain the resin (A).

5. A printed matter obtained by printing the active energy ray-curable resin composition according to any one of claims 1 to 3 onto a substrate.

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