Active energy ray-curable inkjet printing ink composition

Abstract

The object of the present invention is to provide an active energy ray-curable ink composition for inkjet printing, wherein the ink composition has low viscosity, no odor, excellent storage stability, ejection stability, and curability, and no curing wrinkles are generated during curing, and the cured coating film has excellent bending resistance, abrasion resistance, and water resistance. As a solution, an active energy ray-curable ink composition for inkjet printing is provided, characterized in that it satisfies the following conditions A to D. A: 1.0 to 20.0 mass % of amine-modified oligomers are contained in the total active energy ray-polymerizable components. B: 2.0 to 20.0 mass % of (meth)acrylates having alkoxy groups are contained in the total active energy ray-polymerizable components. C: 2.0 to 25.0 mass % of (meth)acrylates having alkyl groups having 10 to 20 carbon atoms are contained in the total active energy ray-polymerizable components. D: 30.0 to 60.0% by mass of at least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, 1,10-decanediol diacrylate and hydroxypivalate neopentyl glycol diacrylate is contained in the total active energy ray-polymerizable components.

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable inkjet printing ink composition and a printed matter obtained using the same. The active energy ray-curable inkjet printing ink composition is suitable for printing on substrates such as paper, containers, colloids, metal foils, glass, wood, cloth, and in particular, corrugated cardboard. Background Art

[0002] As described in Patent Document 1, it is well known that preventing the occurrence of curing wrinkles during the curing of photocurable inkjet inks is a major issue.

[0003] Inkjet ink compositions containing an amine-modified oligomer and a monomer having a plurality of (meth)acryloyl groups are also known, for example, as described in Patent Document 2. However, such ink compositions do not satisfy the conditions C or D of the present invention.

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2007 / 074768

[0006] Patent Document 2: International Publication No. 2017 / 073654 Summary of the invention

[0007] The problem to be solved by the present invention is to provide an active energy ray-curable ink composition for inkjet printing, wherein the ink composition has low viscosity, no odor, excellent storage stability, ejection stability, and curability, and no curing wrinkles are generated during curing, and the cured coating film has excellent bending resistance, abrasion resistance, and water resistance.

[0008] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by a specific composition, thereby completing the present invention.

[0009] That is, the present invention is as follows.

[0010] 1. An active energy ray-curable inkjet printing ink composition, characterized in that it satisfies the following conditions A to D:

[0011] A: 1.0 to 20.0% by mass of the amine-modified oligomer in the total active energy ray-polymerizable components;

[0012] B: 2.0 to 20.0 mass % of the (meth)acrylate having an alkoxy group in the total active energy ray-polymerizable components;

[0013] C: 2.0 to 25.0 mass % of a (meth)acrylate having an alkyl group having 10 to 20 carbon atoms in the total active energy ray-polymerizable components;

[0014] D: 30.0 to 60.0% by mass of at least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, 1,10-decanediol diacrylate and hydroxypivalate neopentyl glycol diacrylate is contained in the total active energy ray-polymerizable components.

[0015] 2. The active energy ray-curable ink composition for inkjet printing according to 1, characterized in that at least a part or all of condition B is a multifunctional (meth)acrylate monomer having an alkoxy group, and the total active energy ray-polymerizable components contain 5.0 to 20.0 mass % of the multifunctional (meth)acrylate monomer having an alkoxy group.

[0016] 3. The active energy ray-curable inkjet printing ink composition according to 1 or 2, wherein the ink composition contains 5.0 to 30.0% by mass of E: a (meth)acrylic acid monomer having a hydroxyl group.

[0017] 4. The active energy ray-curable inkjet printing ink composition according to any one of 1 to 3, further comprising F: a photopolymerization initiator.

[0018] 5. The active energy ray-curable inkjet printing ink composition according to any one of 1 to 4, wherein at least a part of the (meth)acrylate having an alkyl group having 10 to 20 carbon atoms in condition C is lauryl acrylate and / or stearyl acrylate.

[0019] 6. The active energy ray-curable inkjet printing ink composition according to any one of 1 to 5, further comprising G: a colorant.

[0020] The active energy ray-curable ink composition for inkjet printing of the present invention can exhibit the following effects: the ink composition has low viscosity, no odor, excellent storage stability, ejection stability, and curability, and no curing wrinkles are generated during curing, and the cured coating film has excellent bending resistance, friction resistance, and water resistance. DETAILED DESCRIPTION

[0021] The active energy ray-curable inkjet printing ink composition of the present invention satisfies the above conditions A to D. The conditions will be described below in order.

[0022] <Condition A>

[0023] As condition A, the content of the amine-modified oligomer is set to 1.0 to 20.0% by mass in the total polymerizable components of the active energy ray-curable inkjet printing ink composition.

[0024] The amine-modified oligomer includes oligomers of acrylated amine compounds having two active energy ray-polymerizable functional groups and two amino groups in the molecule, namely, acrylated amine compounds such as CN371, CN373, CN383, and CN386 (manufactured by Sartomer).

[0025] If the content of the amine-modified oligomer in the active energy ray-curable inkjet printing ink composition is less than 1.0 mass %, the surface curability and abrasion resistance will deteriorate. If it exceeds 20.0 mass %, the viscosity of the active energy ray-curable inkjet printing ink composition tends to increase, and the storage stability and abrasion resistance will also deteriorate.

[0026] The content of the oligomer having an amino group in the total polymerizable components of the active energy ray-curable inkjet printing ink composition is preferably 1.2% by mass or more, more preferably 1.4% by mass or more, further preferably 1.6% by mass or more, particularly preferably 1.8% by mass or more, and most preferably 5.0% by mass or more. In addition, it is preferably 17.0% by mass or less, and more preferably 15.0% by mass or less.

[0027] <Condition B>

[0028] As condition B, the (meth)acrylate having an alkoxy group is contained in an amount of 2.0 to 20.0% by mass of the total polymerizable components of the active energy ray-curable inkjet printing ink composition.

[0029] The (meth)acrylate monomer having an alkoxy group is not particularly limited. For example, the (meth)acrylic acid monomer includes various monofunctional (meth)acrylate monomers with little odor, bifunctional (meth)acrylate monomers, trifunctional (meth)acrylate monomers, and polyfunctional acrylate monomers having four or more functions. In consideration of the environment, a (meth)acrylate monomer having an alkoxy group derived from biomass can be used.

[0030] Specifically, there can be mentioned: monofunctional alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 3-methoxybutyl (meth)acrylate, and 2-butoxyethyl (meth)acrylate; 2-butoxydiethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxytriethylene glycol (meth)acrylate. Monofunctional (meth)acrylates having a polyalkylene glycol structure and an alkoxy group, such as ethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxytripropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, octyloxypolyethylene glycol-polypropylene glycol mono(meth)acrylate, dodecyloxypolyethylene glycol mono(meth)acrylate, and stearyloxypolyethylene glycol mono(meth)acrylate.

[0031] Furthermore, polyfunctional (meth)acrylates having an alkoxy group such as ethoxylated (3) trimethylolpropane tri(meth)acrylate and propoxylated (2) neopentyl glycol di(meth)acrylate may also be used.

[0032] The (meth)acrylate having an alkoxy group in condition B preferably contains 30 to 100% by mass of the polyfunctional (meth)acrylate having an alkoxy group in condition B. When the polyfunctional (meth)acrylate having an alkoxy group is within this range, the abrasion resistance is excellent.

[0033] If the content of the (meth)acrylate having an alkoxy group is less than 2.0 mass % in the total active energy ray-polymerizable components, the bending resistance may be poor, and if it exceeds 20.0 mass %, the water resistance may be poor.

[0034] The content of the (meth)acrylate having an alkoxy group in the total polymerizable components of the active energy ray-curable inkjet printing ink composition is preferably 4.0% by mass or more, more preferably 8.0% by mass or more, further preferably 10.0% by mass or more, and most preferably 11.0% by mass or more. In addition, it is preferably 18.0% by mass or less, more preferably 16.0% by mass or less, further preferably 14.0% by mass or less, and most preferably 13.0% by mass or less.

[0035] <Condition C>

[0036] As condition C, the content of the (meth)acrylate having an alkyl group having 10 to 20 carbon atoms may be 2.0 to 25.0% by mass in the total active energy ray-polymerizable components. The alkyl group having 10 to 20 carbon atoms may have any of a linear, branched, and alicyclic structures.

[0037] Here, the (meth)acrylate having an alkyl group having 10 to 20 carbon atoms is a monofunctional (meth)acrylate, and examples thereof include tridecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isopentyl (meth)acrylate, isodecyl (meth)acrylate, isotetradecyl (meth)acrylate, isobornyl (meth)acrylate, and cyclohexyl (meth)acrylate.

[0038] If the content of the (meth)acrylate having an alkyl group having 10 to 20 carbon atoms in the active energy ray-curable inkjet printing ink composition is less than 2.0 mass %, the bending resistance may be poor, and if it exceeds 25.0 mass %, the abrasion resistance may be poor.

[0039] The content of the (meth)acrylate having an alkyl group having 10 to 20 carbon atoms in the total polymerizable components of the active energy ray-curable inkjet printing ink composition is preferably 2.5% by mass or more, more preferably 3.0% by mass or more, further preferably 3.5% by mass or more, and most preferably 4.0% by mass or more. Furthermore, it is preferably 20.0% by mass or less, and more preferably 18.0% by mass or less.

[0040] One of the raw materials of the (meth)acrylate having an alkyl group with 10 to 20 carbon atoms is (meth)acrylic acid, and the other raw material is an alcohol with 10 to 20 carbon atoms. The alcohol can be obtained from a plant-derived raw material, for example, and is a substance having renewable carbon. The plant-derived raw material includes plant raw materials such as palm oil, palm kernel oil, and coconut oil.

[0041] Since the alkyl group having 10 to 20 carbon atoms has a large number of carbon atoms, the more (meth)acrylate used as a raw material in the active energy ray-curable inkjet printing ink composition is used, the more biomass-derived carbon can be used in the entire composition.

[0042] <Condition D>

[0043] As condition D, the content of at least one selected from 1,6-hexanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, propoxylated (2) neopentyl glycol diacrylate, 1,10-decanediol diacrylate, and hydroxypivalate neopentyl glycol diacrylate is 30.0 to 60.0% by mass in the total polymerizable components of the active energy ray-curable inkjet printing ink composition.

[0044] If the content of condition D is less than 30.0% by mass in the active energy ray-curable inkjet printing ink composition, curability and abrasion resistance may be deteriorated, and if it exceeds 60.0% by mass, bending resistance may be deteriorated.

[0045] <Condition E>

[0046] As condition E, the content of the (meth)acrylic acid monomer having a hydroxyl group is 5.0 to 30.0% by mass of the total polymerizable components in the active energy ray-curable inkjet printing ink composition. The active energy ray-curable inkjet printing ink composition may or may not contain the (meth)acrylic acid monomer having a hydroxyl group.

[0047] As the (meth)acrylic monomer having a hydroxyl group, a (meth)acrylate monomer is preferred, and one or more monomers selected from the following monomers can be used.

[0048] Hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate, polyethylene glycol mono(meth)acrylates such as diethylene glycol monoethyl ether (meth)acrylate, polypropylene glycol mono(meth)acrylate, and glycol mono(meth)acrylates such as 1,4-cyclohexanedimethanol mono(meth)acrylate, caprolactone-modified (meth)acrylates, hydroxyethyl acrylamide, and EO (ethylene oxide)-modified succinic acid (meth)acrylate, and (meth)acrylic acid monomers having a hydroxyl group such as 4-hydroxybutyl (meth)acrylate, which have little odor, are preferred.

[0049] In the present invention, the content of the (meth)acrylic monomer having a hydroxyl group in the total polymerizable components in the active energy ray-curable inkjet printing ink composition is preferably 7.0% by mass or more and preferably 25.0% by mass or less.

[0050] <Condition H>

[0051] Furthermore, as condition H, a vinyl monomer may be contained. The active energy ray-curable inkjet printing ink composition may contain 1.0 to 20.0% by mass of the vinyl monomer in the total polymerizable components. By containing the vinyl monomer, when printing on corrugated cardboard or the like, and the corrugated cardboard or the like is bent, the bending resistance can be further improved.

[0052] However, the active energy ray-curable inkjet printing ink composition may or may not contain a vinyl monomer.

[0053] The vinyl monomer is not particularly limited and can be, for example, ethylene glycol divinyl ether, triethylene glycol divinyl ether, diethylene glycol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, ethylene glycol monovinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, trimethylolpropane trivinyl ether, or the like.

[0054] Among them, the vinyl monomer is preferably triethylene glycol divinyl ether or the like which has little odor.

[0055] <Compounds other than conditions A to E and H>

[0056] In the present invention, in addition to the polymerizable components targeted in conditions A to E and H, a polymerizable compound may be contained within a range in which the performance is not deteriorated and the odor is small.

[0057] In the description of the following compounds, (poly) before the polyol portion means a condensate of mono- or di- or more polyols.

[0058] (Alkylene glycol di(meth)acrylate)

[0059] (Poly)alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,5-propylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1,5-hexanediol di(meth)acrylate, 2,5-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,2-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate ) acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-2,4-pentanediol di(meth)acrylate Methyl-1,3-pentanediol di(meth)acrylate, dimethyloloctane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate.

[0060] ((Poly)glycerol poly(meth)acrylate)

[0061] Glyceryl di(meth)acrylate, glyceryl tetra(meth)acrylate, diglyceryl tetra(meth)acrylate.

[0062] ((Poly)trimethylolpropane poly(meth)acrylate)

[0063] Trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tetra(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate.

[0064] ((Poly)pentaerythritol poly(meth)acrylate)

[0065] Pentaerythritol tetra(meth)acrylate and its ethylene oxide modified product, dipentaerythritol penta(meth)acrylate and its ethylene oxide modified product, dipentaerythritol hexa(meth)acrylate and its ethylene oxide modified product, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate.

[0066] (Other polyacrylates)

[0067] As the polyacrylate not included in the above, the following compounds can be used.

[0068] Monomers having four or more functions such as pentaerythritol tetracaprolactone tetra(meth)acrylate, ditrimethylolpropane tetracaprolactone tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexane tetra(meth)acrylate, ditrimethyloloctane tetra(meth)acrylate, and tripentaerythritol polyalkylene oxide hepta(meth)acrylate.

[0069] Hydroxypivaloyl hydroxypivalate di(meth)acrylate, hydroxypivaloyl hydroxypivalate dicaprolactone di(meth)acrylate, dimethyloloctane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, and the like.

[0070] In addition, 2-(2-vinyloxyethoxy)ethyl acrylate or methyl 2-(allyloxymethyl)acrylate may or may not be contained.

[0071] <Other polymerizable ingredients>

[0072] Examples of the polymerizable component that can be formulated in the active energy ray-curable inkjet printing ink composition of the present invention include the following compounds.

[0073] Benzyl methacrylate, butyl (meth)acrylate, ethyl carbitol (meth)acrylate, caprolactone (meth)acrylate, methoxytripropylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate.

[0074] In addition, examples thereof include acryloylmorpholine, acrylonitrile, acrylamide, diethylacrylamide, styrene, (meth)acrylic acid, polyurethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, pentaerythritol ethoxytetraacrylate, caprolactam-modified dipentaerythritol hexaacrylate, ethoxylated bisphenol A diacrylate, alkoxylated tetrahydrofurfuryl acrylate, dimethylol-tricyclodecane di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, polytetramethylene glycol diacrylate, trimethylolpropane tri(meth)acrylate and its ethylene oxide modified product, pentaerythritol tri(meth)acrylate, and the like.

[0075] In addition, a monomer having an amide group may or may not be contained.

[0076] <Condition F>

[0077] The active energy ray-curable inkjet printing ink composition of the present invention may contain a photopolymerization initiator. When electron beams are used as active energy beams, a photopolymerization initiator may or may not be contained.

[0078] As the photopolymerization initiator which can be used, for example, the following can be mentioned.

[0079] As acylphosphine oxide-based polymerization initiators, there are bis-2,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzyl-diphenylphosphine oxide (TPO), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Irgacure819 or SB-PI719), ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide (TPOL), and the like.

[0080] As α-hydroxyketone polymerization initiators, there are 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propane-1-one (Irgacure 127), 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone (Irgacure 2959), 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184), oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} (ESACURE ONE), 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 1-hydroxycyclohexyl phenyl ketone, bis[4-(2-hydroxy-2-methylpropionyl)phenyl]ether (KIP160), and the like.

[0081] In addition, benzophenone, 4,4'-diethylaminobenzophenone, ethyl Michler's ketone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropane-1-one, 4'-(methylthio)-α-morpholino-α-methylpropiophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2,4-diethylthioxanthone, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butane-1-one, polymer type initiators (Omnipol TP, Omnipol BP), 1-〔4-(4-benzoylphenylsulfanyl)phenyl〕-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one (ESACURE1001M).

[0082] Such photopolymerization initiators are commercially available, and can be obtained, for example, by purchasing trade names such as Irgacure 907, Irgacure 369, Irgacure 184, Irgacure 379, Irgacure 819, and TPO. A plurality of photopolymerization initiators may be used in combination.

[0083] Among them, it is preferred to use an acylphosphine oxide polymerization initiator and an α-hydroxyketone polymerization initiator in combination, and further preferred to use 2,4,6-trimethylbenzyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and oligomeric {2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} in combination.

[0084] Furthermore, the acylphosphine oxide polymerization initiator and the α-hydroxyketone polymerization initiator are preferably prepared in a mass ratio of acylphosphine oxide polymerization initiator:α-hydroxyketone polymerization initiator=8:1 to 2:1, more preferably 7:1 to 3:1.

[0085] Furthermore, 2,4,6-trimethylbenzyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide are preferably prepared in a mass ratio of 2,4,6-trimethylbenzyl-diphenylphosphine oxide:bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide=2:3 to 10:1, more preferably 1:1 to 8:1.

[0086] In addition, the thioxanthone-based photopolymerization initiator may not be contained.

[0087] Furthermore, in order to promote the curing property with respect to ultraviolet rays using a light emitting diode (LED) as a light source, the active energy ray-curable inkjet printing ink composition of this embodiment may also contain the following photosensitizer (compound): a compound having light absorption characteristics mainly in the ultraviolet wavelength region above 400 nm and exhibiting a sensitizing function for the curing reaction by light of a wavelength in this range.

[0088] By using such a sensitizer, the ink composition of this embodiment can promote LED curability.

[0089] The above-mentioned photosensitizer is an anthracene sensitizer, a thioxanthone sensitizer, etc., preferably a thioxanthone sensitizer. Photosensitizers can be used in combination. Specifically, the photosensitizer is an anthracene sensitizer such as 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-bis(2-ethylhexyloxy)anthracene; thioxanthone sensitizers such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, etc. As representative examples of commercial products, anthracene sensitizers include DBA and DEA (manufactured by Kawasaki Chemical Industries, Ltd.), and thioxanthone sensitizers include DETX, ITX, CPTX (manufactured by Lambson), Omnipol TX (manufactured by IGM), etc.

[0090] When a photosensitizer is contained, the content of the photosensitizer in the ink composition is preferably greater than 0 and less than 5.0% by mass. When the content of the photosensitizer exceeds 5.0% by mass, the effect of the ink composition due to the addition of the photosensitizer is difficult to improve, and there is a tendency to lead to excessive addition.

[0091] In addition, when a thioxanthone-type sensitizer is included as a photosensitizer, since there is a tendency for the active energy ray-curable inkjet printing ink composition to turn yellow, the hue will become more yellowish than the color based on pigments (original hue), so it is preferred to appropriately determine the content of the thioxanthone-type sensitizer for each color.

[0092] Specifically, it is preferred that the ink composition does not contain a thioxanthone sensitizer as a photosensitizer in a white ink composition and a transparent ink composition that are easily affected by a change in hue. In addition, in a magenta ink composition and a cyan ink composition, since a vinylamide compound is used as a photopolymerizable compound, the cured coating film that becomes yellow will fade, and the hue change is likely to cause problems. Therefore, the photosensitizer is preferably used within a range where the hue does not cause problems. In addition, in a black ink composition and a yellow ink composition, even if there is a discoloration, the hue is unlikely to be affected, and the photopolymerization is inferior to other hues, so it is preferred to use a thioxanthone sensitizer as a photopolymerization initiator.

[0093] Acrylic resins, vinyl chloride resins, vinyl chloride-vinyl acetate resins and ethylene-vinyl acetate resins, styrene-acrylic resins, styrene-maleic acid resins, rosin resins, rosin ester resins, petroleum resins, coumarone resins, rosin phenol resins, phenolic resins, ketone resins, polyurethane resins, melamine resins, urea-formaldehyde resins, epoxy resins, cellulose resins, xylene resins, alkyd resins, aliphatic hydrocarbon resins, butyral resins, maleic acid resins, fumaric acid resins, etc. may also be used in combination within a range that does not reduce the performance of the active energy ray-curable ink jet printing ink composition of the present invention.

[0094] <Condition G>

[0095] As the colorant contained in the active energy ray-curable inkjet printing ink composition of the present invention, known pigments and dyes used in conventional active energy ray-curable inkjet printing ink compositions can be used, preferably color pigments such as organic color pigments and inorganic color pigments. Thus, active energy ray-curable inkjet printing ink compositions of various colors can be obtained.

[0096] The organic coloring pigments include dye lake pigments, azo pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazines pigments, indigo pigments, thioindigo pigments, perylene pigments, perindole pigments, dione pyrrolopyrrole pigments, isoindolinone pigments, nitro pigments, nitroso pigments, flavonoid pigments, quinophthalone pigments, pyranthrone pigments, and indanthrone pigments.

[0097] Inorganic coloring pigments include colored pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, ultramarine, Prussian blue, iron black, chromium oxide green, carbon black, black lead, etc. (also including non-color coloring pigments such as white and black), and physical pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, talc, etc.

[0098] Specific examples of representative hues of the above-mentioned coloring pigments are as follows: Yellow pigments include CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 42, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 108, 109, 114, 120, 128, 129, 138, 139, 150, 151, 155, 166, 180, 184, 185, 213, etc., preferably CI Pigment Yellow 150, 155, 180, 213, etc.

[0099] Magenta pigments include CI Pigment Red 5, 7, 12, 19, 22, 38, 48:1, 48:2, 48:4, 49:1, 53:1, 57, 57:1, 63:1, 101, 102, 112, 122, 123, 144, 146, 149, 168, 177, 178, 179, 180, 184, 185, 190, 202, 209, 224, 242, 254, 255, 270, CI Pigment Violet 19, etc., preferably CI Pigment Red 122, 202, CI Pigment Violet 19, etc.

[0100] The cyan pigment is CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 22, 27, 29, 60, etc., preferably CI Pigment Blue 15:4, etc.

[0101] The black pigment is carbon black CI Pigment Black 7 or the like.

[0102] The white pigment is titanium oxide, aluminum oxide, or the like, and titanium oxide or the like surface-treated with various materials such as aluminum oxide and silicon dioxide is preferred.

[0103] The content of the colorant is preferably 1% by mass or more and preferably 20% by mass or less in the ink composition. When the content of the colorant is within the above range, the image quality of the printed material obtained from the ink composition is appropriate and the viscosity characteristics are excellent.

[0104] (Pigment dispersant)

[0105] When the active energy ray-curable inkjet printing ink composition of the present invention contains a pigment, examples of the pigment dispersant that may be contained include ionic or nonionic surfactants, and anionic, cationic or nonionic polymer compounds.

[0106] Among them, preferred are polymer compounds, for example, carbodiimide compounds described in Japanese Patent Application Laid-Open No. 2004-083872, International Publication No. WO2003 / 076527, International Publication No. WO2004 / 000950, copolymers containing basic functional groups such as Ajisper PB821, 822 (manufactured by Ajinomoto Fine Technologies Co., Ltd.), SOLSPERSE 56000 (manufactured by LUBRIZOL), SOLSPERSE 32000 (manufactured by LUBRIZOL), SOLSPERSE 39000 (manufactured by LUBRIZOL), DISPERBYK (manufactured by BYK JAPAN), etc. These pigment dispersants may be used alone or in combination of two or more.

[0107] Among them, copolymers containing a basic functional group having an amine value of 10 to 40 mgKOH / g are preferred.

[0108] The pigment dispersant may be appropriately selected and used according to the type of the pigment and the type of the organic solvent used.

[0109] (Organic Solvent)

[0110] The active energy ray-curable inkjet printing ink composition of the present invention may be a so-called solvent-free type in which all liquid components are cured by a curing reaction, or a solvent-based type in which the printed coating is dried to remove the solvent and then cured. However, water is not used as a solvent.

[0111] Hereinafter, the case where the active energy ray-curable inkjet printing ink composition of the present invention contains an organic solvent will be described.

[0112] The organic solvent that may be contained in the active energy ray-curable inkjet printing ink composition of the present invention includes propylene carbonate, diethylene glycol dialkyl ether, and dipropylene glycol alkyl ether acetate.

[0113] As the diethylene glycol dialkyl ether, diethylene glycol ethyl methyl ether and / or diethylene glycol diethyl ether are preferably used, and other diethylene glycol dialkyl ethers may be used in combination.

[0114] As the dipropylene glycol alkyl ether acetate, those having an alkyl group with 6 or less carbon atoms are preferred, those having an alkyl group with 3 or less carbon atoms are more preferred, and those having an alkyl group with 2 or less carbon atoms are further preferred.

[0115] Furthermore, in order to adjust the drying properties and further improve the anti-spotting property, an alkylene glycol derivative having a flash point of 50 to 150° C. may be used in combination with diethylene glycol dialkyl ether.

[0116] Examples of such alkylene glycol derivatives having a flash point of 50 to 150° C. include (poly)ethylene glycol dialkyl ethers such as triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tetrapropylene glycol diethyl ether, and tetrapropylene glycol dimethyl ether, (poly)propylene glycol dialkyl ethers such as propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monobutyl ether. propylene glycol monoalkyl ethers such as propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, (poly)propylene glycol monoalkyl ethers such as monoalkyl esters, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol (Poly)ethylene glycol monoalkyl ethers such as monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, and tetraethylene glycol monobutyl ether, (Poly)ethylene glycol monoalkyl ether monoalkyl esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, and triethylene glycol monomethyl ether acetate, ethylene glycol diacetate, diethylene glycol diacetate, triethylene glycol monobutyl ether acetate, (Poly)ethylene glycol diesters such as ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate and the like.

[0117] Among the alkylene glycol derivatives having a flash point of 50 to 150° C., diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether are mentioned first.

[0118] Furthermore, within the range that does not significantly change the flash point of the entire solvent, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, etc., which have a flash point outside the range of 50 to 150°C, may be used in combination.

[0119] (Other ingredients)

[0120] Furthermore, the active energy ray-curable inkjet printing ink composition of the present invention may contain various additives such as surfactants, plasticizers, polymerization inhibitors, surface conditioners, UV inhibitors, light stabilizers, and antioxidants as needed.

[0121] (Viscosity of Active Energy Ray-Curable Inkjet Printing Ink Composition)

[0122] The viscosity of the active energy ray-curable inkjet printing ink composition of the present invention at 25° C. is preferably 30.0 mPa·s or less. If the viscosity exceeds 30 mPa·s, it may be difficult to discharge the ink composition from the inkjet printing nozzle.

[0123] The viscosity is measured at 25° C. and 20 rpm using an E-type viscometer (trade name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.).

[0124] (Manufacture of Active Energy Ray-Curable Inkjet Printing Ink Composition)

[0125] Next, a method for producing the active energy ray-curable inkjet printing ink composition of the present invention using these materials will be described.

[0126] The active energy ray-curable inkjet printing ink composition of the present invention can be obtained by, for example, dispersing and mixing using a disperser such as a wet circulation mill, a bead mill, a ball mill, a sand mill, an attritor, a roll mill, a DCP mill, a stirrer, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a high-pressure homogenizer (Micro fluidizer, Nanomizer, Ultimizer, GenusPY, DeBEE2000, etc.), or a pearl mill, and adjusting the viscosity of the active energy ray-curable inkjet printing ink composition to 2 to 10 mPa·s.

[0127] The total organic solvent content in the active energy ray-curable inkjet printing ink composition of the present invention is the amount obtained by deducting the total amount of each solid component and other additives used as needed from the total amount of the ink composition, and the ink viscosity is preferably appropriately changed so as to fall within the above range.

[0128] The active energy ray-curable inkjet printing ink composition of the present invention obtained above can be used on a substrate having at least a surface layer made of a resin such as paper or a vinyl chloride polymer or an ethylene-vinyl acetate copolymer, using an inkjet printer.

[0129] (Method for producing printed matter)

[0130] Next, a method for producing a printed matter using the active energy ray-curable inkjet printing ink composition of the present invention will be described.

[0131] The method for producing a printed article of the present invention includes the step of printing the above-mentioned active energy ray-curable inkjet printing ink composition on a substrate by an inkjet method.

[0132] The substrate is not particularly limited. For example, the substrate is various resin substrates, paper, containers, colloids, metal foils, glass, wood, cloth, etc. After the ink composition of this embodiment is printed on the substrate, even when the substrate is bent, it also exhibits excellent bending resistance. Therefore, the ink composition is particularly suitable for use when the substrate is a substrate for bending purposes such as corrugated cardboard.

[0133] When the substrate is a corrugated cardboard such as C cardboard (Jute liner) or K cardboard (kraft liner), the ink composition can be directly applied to the corrugated cardboard, or a pre-coat layer (primer layer) can be provided on the corrugated cardboard, and then applied after corona discharge treatment. In recent years, due to environmental considerations, corrugated cardboard sometimes uses old paper or recycled paper. When K cardboard is used as the corrugated cardboard, the surface is rough, the color is not bright, and the ink permeability during printing is high. Therefore, when the ink composition is printed on the corrugated cardboard, the brown color of the base paper of the base cardboard is likely to become the cause of poor printing quality.

[0134] Especially when the color of the substrate appears in the printed part, the inkjet image looks darker, which may damage the beauty of the printed material. For this kind of corrugated board, in order to solve the above-mentioned unevenness, etc., a pre-coating layer can be appropriately set.

[0135] The purpose of providing a pre-coat layer (primer layer) is to adjust the whiteness and color tone of the cardboard base paper constituting the corrugated cardboard and to improve the whiteness of the base, etc. The pre-coat layer can be formed by applying a pre-coat agent containing a pigment and a binder.

[0136] The pigment is not particularly limited. For example, the pigment may include, in addition to titanium dioxide (anatase, rutile), body pigments such as aluminum hydroxide, barium sulfate, calcium carbonate, amorphous silica, and clay. In addition, the content of the white pigment is preferably 20 to 85 parts by mass, more preferably 20 to 80 parts by mass, in 100 parts by mass of the pre-coat agent.

[0137] The binder resin used for the pre-coat layer of the corrugated board is preferably an aqueous resin. The aqueous resin is preferably a natural resin, a synthetic resin, etc., and more preferably a starch derivative, casein, shellac, a polyvinyl alcohol derivative, an acrylic acid and a maleic acid resin, etc. More specifically, the aqueous resin is suitable for using acrylic acid or methacrylic acid and its alkyl esters, or an aqueous acrylic resin, aqueous styrene-acrylic resin, aqueous styrene-maleic acid resin, aqueous styrene-acrylic acid-maleic acid resin, aqueous polyurethane resin, aqueous polyester resin, etc., which are copolymerized with styrene as the main monomer component. The content of the binder resin is preferably 1 to 25 parts by mass in 100 parts by mass of the pre-coating agent, and more preferably 1 to 15 parts by mass.

[0138] The aqueous medium that can be used in the pre-coat layer (primer layer) can be water or a mixture of water and a water-miscible solvent. The water-miscible solvent is lower alcohols, polyols and their alkyl ethers or alkyl esters, etc. Specifically, the water-miscible solvent is lower alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerol, etc. Polyols, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoacetate, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, etc.

[0139] In addition to the above-mentioned components, the pre-coat layer may also contain various additives such as film formers, pigment dispersants or pigment dispersing resins, anti-caking agents, wetting agents, viscosity regulators, pH regulators, defoaming agents, general surfactants, etc., as appropriate.

[0140] The method for producing the pre-coat agent using the above-mentioned various materials is not particularly limited. For example, the method for producing the pre-coat agent includes a general method as follows: a white pigment, an aqueous binder resin, water, a water-miscible solvent as required, and a pigment dispersant or a pigment dispersion resin are mixed and kneaded, and an additive, water, a water-miscible solvent as required, and the remainder of the prescribed material are further added and mixed.

[0141] The pre-coat agent can be easily obtained by mixing the required amounts of the above-mentioned components and mixing and dispersing them using a high-speed stirrer such as a homomixer or a laboratory mixer or a disperser such as a three-roll mill or a bead mill.

[0142] When a primer layer is provided, the thickness of the primer layer (the amount of the pre-coating agent applied) is not particularly limited. The primer layer preferably has a solid content applied amount of 0.1 to 5 g / m 2 By keeping the thickness of the primer layer (the amount of the pre-coating agent applied) within the above range, it is easy to appropriately adjust the whiteness or color tone of the corrugated cardboard.

[0143] Specific examples of the printing and curing methods of the active energy ray-curable inkjet printing ink composition of the present invention include a method in which the active energy ray-curable inkjet printing ink composition of the present invention is ejected onto a substrate through an inkjet head, and then the coating film of the ink composition of the present invention deposited on the substrate is exposed to light to cure the ink composition.

[0144] For example, the ejection onto the substrate (printing of the image) can be performed by providing the active energy ray-curable inkjet printing ink composition of the present invention to a low viscosity corresponding print head of an inkjet recording printer, and ejecting the ink composition from the print head in such a manner that the film thickness of the coating on the substrate reaches, for example, 1 to 60 μm. In addition, light exposure and curing (curing of the image) can be performed by irradiating the coating of the active energy ray-curable inkjet printing ink composition of the present invention applied as an image on the substrate with active energy rays.

[0145] As the inkjet printing device for printing the active energy ray-curable inkjet printing ink composition of the present invention, a conventionally used inkjet printing device can be used. In addition, when a continuous inkjet printing device is used, a conductive agent is further added to the active energy ray-curable inkjet printing ink composition of the present invention to adjust the conductivity.

[0146] As the active energy ray source during the curing of the above-mentioned coating film, ultraviolet rays (UV lamp), ultraviolet rays (light emitting diode (LED)), electron rays, visible rays, etc. can be listed. As a specific device, for example, one or more selected from ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, mercury xenon lamps, metal halide lamps, high power metal halide lamps, xenon lamps, pulsed light emitting xenon lamps, deuterium lamps, fluorescent lamps, Nd-YAG 3-fold frequency lasers, He-Cd lasers, nitrogen lasers, Xe-Cl excimer lasers, Xe-F excimer lasers, semiconductor excitation solid lasers, LED lamps, etc. can be used. From an environmental perspective, it is preferably a light emitting diode (LED) that generates ultraviolet rays with a luminescence peak wavelength in the range of 350 to 420 nm.

[0147] Ultraviolet light using a light emitting diode (LED) as a light source refers to “light irradiated from a light emitting diode that generates ultraviolet light with a peak emission wavelength in the range of 350 to 420 nm”.

[0148] The temperature of the ink composition during printing may be room temperature, which is approximately 20 to 26° C., or another temperature.

[0149] Example

[0150] The present invention is further described in detail by way of examples below, but the present invention is not limited to these examples. In addition, unless otherwise specified, "%" means "mass %" and "parts" means "mass parts".

[0151] The materials used in the following examples and comparative examples are as follows: The unit of the numerical values ​​in the columns of pigment, dispersant, resin, solvent and total in the table is "mass %".

[0152] (pigment)

[0153] PY155: Pigment Yellow 155

[0154] PV19: Pigment Violet 19

[0155] PB15:4: Pigment Blue 15:4

[0156] P.Bl.7: Pigment Black 7

[0157] PG7: Pigment Green 7

[0158] PO13: Pigment Orange 13

[0159] PV23: Pigment Violet 23

[0160] PY150: Pigment Yellow 150

[0161] (Pigment dispersant)

[0162] PB822 (AJISPER PB822, manufactured by Ajinomoto Fine Technologies Co., Ltd.)

[0163] (Amine modified oligomer)

[0164] CN371 (manufactured by Sartomer)

[0165] (Photopolymerization Initiator)

[0166] TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

[0167] SB-PI719: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0168] Esacure ONE: Oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone}

[0169] TPO-L: ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate

[0170] Omnipol TP (manufactured by IGM)

[0171] (Sensitizer)

[0172] Omnipol TX (manufactured by IGM)

[0173] DETX: diethylthioxanthone (produced by Lambson)

[0174] (Inhibitor)

[0175] MEHQ (monomethyl hydroquinone ether)

[0176] HQ (Hydroquinone)

[0177] (Surface Conditioner)

[0178] BYK-331: Silicone surfactant

[0179] (Examples 1 to 14, Comparative Examples 1 to 5)

[0180] <Production of Active Energy Ray-Curable Inkjet Printing Ink Composition>

[0181] The materials were stirred and mixed according to the proportions in Table 1 (the proportions of the materials were expressed as mass %) and then dispersed to obtain pigment dispersions of various colors. Then, according to the proportions in Table 2, active energy ray-curable inkjet printing ink compositions of Examples were obtained.

[0182] <Corrugated cardboard base material>

[0183] K paperboard, C paperboard

[0184] <Pre-coat>

[0185] 45 parts by mass of calcium carbonate with an average particle size of 0.05 μm, 25 parts by mass of styrene-maleic acid resin (solid content 25%) with an acid value of 170 mgKOH / g, and 30 parts by mass of water were dispersed with a bead mill to obtain a 45% slurry of calcium carbonate. 80 parts by mass of 45% slurry of calcium carbonate and 20 parts by mass of styrene-maleic acid resin (solid content 25%) with an acid value of 170 mgKOH / g were mixed and stirred to obtain a pre-coating agent.

[0186] <Applying pre-coating agent to K paperboard>

[0187] Use a 0.1 mm Mayer bar to achieve a coating amount of about 4 g / m 2 The pre-coating agent prepared as described above is applied to the K paperboard in a coating amount of . Next, the pre-coating agent-coated surface is dried by hot air drying.

[0188] <Evaluation Method and Evaluation Criteria>

[0189] The evaluation criteria described in Table 2 are as follows.

[0190] (Viscosity)

[0191] The viscosity of the active energy ray-curable inkjet printing ink compositions obtained in Examples and Comparative Examples was measured using an E-type viscometer (trade name: RE100L viscometer, manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25° C. and a rotor speed of 20 rpm.

[0192] (Coating odor)

[0193] After forming a coating film on the substrate in a size of 8 cm x 12 cm and curing it, the substrate was placed in a 24 cm x 34 cm zipper bag and the odor inside the bag was checked after one hour. Ten people were asked to smell it and evaluate it using the following five levels. The average value of the ten people is rounded off to the nearest decimal point in the table.

[0194] 5: Odorless

[0195] 4: Low odor

[0196] 3: Medium odor

[0197] 2: Strong odor

[0198] 1: Strong odor

[0199] (Storage stability)

[0200] The active energy ray-curable inkjet printing ink composition was placed in a glass bottle, sealed, and stored at 70° C. for 7 days. The state after storage was evaluated based on the following evaluation criteria.

[0201] ◯: No increase in thickness or precipitation was observed in the active energy ray-curable inkjet printing ink composition.

[0202] △: The active energy ray-curable inkjet printing ink composition was found to have increased viscosity or precipitates to such an extent that the composition recovered to its original state upon light shaking.

[0203] ×: The active energy ray-curable inkjet printing ink composition was found to have increased viscosity or precipitation to such an extent that it did not return to its original state even when vigorously shaken.

[0204] (Discharge stability)

[0205] The inkjet recording device equipped with an inkjet nozzle and the active energy ray-curable inkjet printing ink composition were left at an ambient temperature of 25° C. for 24 hours to allow the temperature of the inkjet recording device and the active energy ray-curable inkjet printing ink composition to reach 25° C. Then, the ink composition was used to continuously print (print) on K paperboard and C paperboard coated with a pre-coating agent at 25° C., and the ejection stability was evaluated according to the following evaluation criteria.

[0206] ○: There is no printing disturbance and the printing is stably ejected.

[0207] △: There is a little printing disturbance, but the printing is basically stable.

[0208] ×: There is printing disturbance or stable ejection is not possible.

[0209] (Curing property)

[0210] The inkjet recording device equipped with an inkjet nozzle and the active energy ray-curable inkjet printing ink composition were left at an ambient temperature of 25° C. for 24 hours to allow the temperature of the inkjet recording device and the active energy ray-curable inkjet printing ink composition to reach 25° C. Then, the ink composition was continuously printed (printed) on K paperboard and C paperboard coated with a pre-coating agent at 25° C., and then a UV-LED light lamp manufactured by Phoseon Technology was used at a distance of 2 cm between the lamp and the ink-coated surface at a UV cumulative light dose of 180 mJ / cm 2 Allow to solidify.

[0211] Then, a conveyor-type light irradiation device (STM-250E-16 manufactured by Heraeus, lamp: Z-8 lamp (metal halide type)) was used at 120 W × 50 m / min and UV cumulative light intensity of 75 mJ / cm 2 The irradiation was performed under the irradiation conditions of 250-260 nm, 280-320 nm, 320-390 nm, and 395-445 nm (UV cumulative light intensity was obtained by measuring the irradiation intensity in the measurement ranges of 250-260 nm, 280-320 nm, 320-390 nm, and 395-445 nm using UVIMAP (UM365H-S) manufactured by EIT Corporation as a measuring instrument). The obtained curable coating film was wiped with a cotton swab, and the curability was evaluated by the peeling condition according to the following evaluation criteria.

[0212] ○: No peeling.

[0213] △: There is some peeling.

[0214] ×: There is peeling.

[0215] (Curing wrinkles)

[0216] The ink composition was printed on K paperboard and C paperboard coated with a pre-coating agent, and the printed samples were visually evaluated for the presence or absence of cured wrinkles.

[0217] ○: No curing wrinkles. ×: Curing wrinkles.

[0218] (Bending resistance)

[0219] The ink composition was printed on the pre-coat layer of K paperboard or C paperboard having a pre-coat layer formed on one side, and the paperboard was folded 90 degrees with the printed surface facing outward (with the backs of the non-printed surfaces of the K paperboard and C paperboard facing each other), and evaluated according to the following evaluation criteria.

[0220] ○: No linear cracks or fine cracks were generated in the coating film when it was bent.

[0221] △: Micro cracks occurred when bending.

[0222] ×: Linear cracks occurred when the sample was bent.

[0223] (Abrasion resistance)

[0224] The cured film obtained in the evaluation of the curability was rubbed with a bleached cloth at 500 g x 200 times using a Gakushin type fastness tester (manufactured by Daiei Kagaku Seiki Mfg. Co., Ltd.), and the peeling of the cured film from the K paper board and C paper board coated with the pre-coating agent was visually observed and evaluated according to the following evaluation criteria.

[0225] ○: There is no peeling of the cured film.

[0226] △: The surface of the cured film has scratches.

[0227] ×: The cured film peeled off and the sheet was visible.

[0228] (Water resistance)

[0229] The cured film obtained in the evaluation of the curability was rubbed with a bleached cloth soaked in water at a weight of 500 g for 30 times using a Gakushin type fastness tester (manufactured by Daiei Kagaku Seiki Mfg. Co., Ltd.), and peeling of the cured film from the K paper board and C paper board coated with the pre-coating agent was visually observed, and evaluation was performed according to the following evaluation criteria.

[0230] ○: There is no peeling of the cured film.

[0231] △: The surface of the cured film has scratches.

[0232] ×: The cured film peeled off and the sheet was visible.

[0233] [Table 1]

[0234]

[0235] [Table 2]

[0236]

[0237]

[0238] According to the examples of the present invention, that is, according to each embodiment, an active energy ray-curable ink composition for inkjet printing can be obtained, which has low viscosity, no odor, excellent storage stability, ejection stability, and curability, and does not produce curing wrinkles during curing. The cured coating film has excellent bending resistance, friction resistance and water resistance.

[0239] However, according to Comparative Example 1 which did not contain an amine-modified oligomer, curability, bending resistance and abrasion resistance were poor, and according to Comparative Example 2 which contained an excessive amount of an amine-modified oligomer, viscosity was high, and storage stability and discharge stability were poor.

[0240] Comparative Example 3 in which the content of the component according to Condition C was small had poor bending resistance, and Comparative Example 4 in which the content of the component according to Condition C was excessive had poor storage stability, generated curing wrinkles, and had poor abrasion resistance.

[0241] In addition, in Comparative Example 5 in which the component according to Condition B was excessive, the water resistance of the coating film was poor.

Claims

1. An active energy ray-curable inkjet printing ink composition, characterized in that: Meet the following conditions A~D: A: 1.0 to 20.0 mass % of the total active energy ray polymerizable components; B: 2.0 to 20.0 mass % of the (meth)acrylate having an alkoxy group in the total active energy ray-polymerizable components; C: 2.0 to 25.0 mass % of a (meth)acrylate having an alkyl group having 10 to 20 carbon atoms in the total active energy ray-polymerizable components; D: 30.0 to 60.0% by mass of at least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, 1,10-decanediol diacrylate and hydroxypivalate neopentyl glycol diacrylate in the total active energy ray-polymerizable components; The ink composition contains 5.0 to 30.0% by mass of E: a (meth)acrylic acid monomer having a hydroxyl group.

2. The active energy ray-curable inkjet printing ink composition according to claim 1, wherein At least a part or all of the condition B is a polyfunctional (meth)acrylate monomer having an alkoxy group, and the polyfunctional (meth)acrylate monomer having an alkoxy group is contained in an amount of 5.0 to 20.0% by mass in the total active energy ray-polymerizable components.

3. The active energy ray-curable inkjet printing ink composition according to claim 1 or 2, wherein: Contains F: photopolymerization initiator.

4. The active energy ray-curable inkjet printing ink composition according to claim 1 or 2, wherein: At least a part of the alkyl (meth)acrylate having 10 to 20 carbon atoms in condition C is lauryl acrylate and / or stearyl acrylate.

5. The active energy ray-curable inkjet printing ink composition according to claim 1 or 2, wherein: Contains G: Colorant.

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