Active energy X-ray curable ink composition for inkjet printing

Abstract

While an inkjet ink composition for reducing migration is known, the present invention addresses the challenge of printing on films for food packaging applications requiring more stringent properties, while maintaining sufficient adhesion to resin films and excellent LED curability. As a solution, an active energy radiation-curable inkjet ink composition is provided, characterized by satisfying all of the following conditions (A) to (E): (A) the total polymerizable component contains 20.0 to 60.0% by mass of a hydroxyl-containing monofunctional (meth)acrylate; (B) it contains a polyfunctional monomer having an ether bond; (C) the total polymerizable component contains 10.0 to 50.0% by mass of an amine-modified oligomer; (D) it contains ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate as a polymerization initiator; and (E) it contains a polymeric sensitizer.

Description

Technical Field

[0001] This invention relates to an ink composition for active energy ray curable inkjet printing and a printing method thereof. Background Technology

[0002] As described in Patent Document 1, an inkjet ink composition containing a polymeric initiator having an acylphosphine structure, a polymeric compound, and a colorant, and exhibiting low migration, is known.

[0003] Furthermore, it is known that OMNIPOL TX may be contained as a sensitizer, and tripropylene glycol diacrylate or EO-modified trimethylolpropane triacrylate may be used as the polymerizable compound.

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-185319 Summary of the Invention

[0006] As described in the aforementioned patent documents, an inkjet ink composition for reducing migration is known. However, apart from this, there has been no work on printing on films for food packaging applications requiring even stricter properties, while still achieving sufficient adhesion to resin films and excellent LED curability. Not only for inkjet ink compositions, but also when ink compositions are used in food packaging materials, there are concerns about ink composition transfer (migration) into the food. Furthermore, in printed materials printed with UV-based or other curable ink compositions, unreacted monomers or photopolymerization initiators sometimes migrate.

[0007] As a material that is difficult to migrate, it contains polymer initiators, some monomers, and oligomers, but it is difficult to adjust the viscosity to the range that can be sprayed out by an inkjet printhead.

[0008] The inventors conducted in-depth research to solve the above-mentioned problems and found that by preparing an active energy ray curable inkjet ink composition with a specific composition, the above-mentioned problems can be solved, thus completing the present invention.

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

[0010] 1. An active energy radiation-curable ink composition for inkjet printing, characterized in that it satisfies all of the following conditions (A) to (E):

[0011] (A) The total amount of polymerizable components contains 20.0 to 60.0% by mass of hydroxyl-containing monofunctional (meth)acrylates.

[0012] (B) Contains polyfunctional monomers with ether bonds.

[0013] (C) The total amount of polymerizable components contains 10.0~50.0% by mass of amine-modified oligomers.

[0014] (D) As a polymerization initiator, it contains ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate.

[0015] (E) Contains a high molecular weight sensitizer.

[0016] 2. The active energy ray curable ink composition for inkjet printing according to 1, characterized in that (E) the polymeric sensitizer is a thioxanthone compound.

[0017] 3. The active energy ray curable inkjet ink composition according to 1 or 2, characterized in that, relative to 100 parts by mass of the total polymerizable components of the active energy ray curable inkjet ink composition, it further contains 1.0 to 10.0 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0018] 4. The active energy ray curable inkjet ink composition according to any one of 1 to 3, characterized in that, relative to 100 parts by weight of the total polymerizable components of the active energy ray curable inkjet ink composition, it contains 1.0 to 10.0 parts by weight of ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate.

[0019] 5. The active energy ray curable ink composition for inkjet printing according to any one of 1 to 4, characterized in that (E) the polymeric sensitizer is (2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester.

[0020] 6. The active energy ray curable ink composition for inkjet printing according to any one of 1 to 5, characterized in that (F) the viscosity at 45°C is 38.0 cps or more, and the viscosity at 80°C is 15 cps or less.

[0021] 7. The active energy ray curable inkjet ink composition according to any one of 1 to 6, characterized in that it contains a polyfunctional monomer without ether bonds and / or a monofunctional (meth)acrylate alkyl ester.

[0022] The active energy ray curable ink composition of the present invention exhibits excellent anti-migration properties suitable for food packaging applications, as well as excellent adhesion to resin films and LED curability. In particular, inkjet printing can be performed under heating conditions, and the viscosity can be adjusted to an appropriate range, with good curing properties and excellent adhesion to various substrates. Furthermore, even when printing under heating conditions, it effectively prevents migration of the printed area.

[0023] Furthermore, in the printing section formed by printing and curing an active energy ray-curable inkjet ink composition, components that can be extracted by an aqueous ethanol solution, including unpolymerized components or a portion of the initiator, are called migrating components. Detailed Implementation

[0024] The following description pertains to the active energy ray curable inkjet ink composition (hereinafter sometimes simply referred to as "ink composition") of the present invention. Furthermore, if multiple components of a compound satisfy the conditions (A) to (C) below exist, then the compound may be included in all such satisfying conditions.

[0025] Furthermore, the total polymerizable component in this invention is all the components that polymerize by reacting with each other during curing, including the monomers and oligomers contained in the ink composition.

[0026] (A) Hydroxyl-containing monofunctional (meth)acrylates

[0027] The active energy ray curable inkjet ink composition of the present invention contains a hydroxyl-containing monofunctional (meth)acrylate. Examples of such hydroxyl-containing monofunctional (meth)acrylates include:

[0028] Polyethylene glycol mono(meth)acrylates, including hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, hydroxypentyl methacrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, etc., are used in the production of polyethylene glycol mono(meth)acrylates. Polypropylene glycol mono(meth)acrylate, tripropylene glycol mono(meth)acrylate, etc., 1,6-hexanediol mono(meth)acrylate, glycerol mono(meth)acrylate, 2-hydroxy-3-chloropropyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 2-hydroxy-3-allyloxypropyl(meth)acrylate, 2-hydroxy-3-allyloxypropyl(meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, etc.

[0029] Furthermore, the total amount of polymerizable components in this invention contains 20.0 to 60.0% by mass of the (A) hydroxyl-containing monofunctional (meth)acrylate. Preferably, it is 25.0% by mass or more, more preferably 30.0% by mass or more, further preferably 35.0% by mass or more, and most preferably 38.0% by mass or more. More preferably, it is 58.0% by mass or less, more preferably 55.0% by mass or less, further preferably 53.0% by mass or less, and most preferably 50.0% by mass or less. If it is less than 20.0% by mass, sufficient curing or adhesion cannot be achieved; if it exceeds 60.0% by mass, sufficient curing cannot be achieved.

[0030] (B) Polyfunctional monomers with ether bonds

[0031] The active energy ray curable ink composition of the present invention contains a multifunctional monomer having an ether bond.

[0032] Furthermore, the polyfunctional monomers with ether bonds are as follows, including ether-containing poly(meth)acrylate compounds, ether-containing polyvinyl compounds, and vinyl ether-containing (meth)acrylate compounds.

[0033] (Ether-containing poly(meth)acrylate compounds)

[0034] Examples include: neopentyl glycol (PO) modified diacrylate ((PO)NPGDA), dipropylene glycol (DPGDA), EO (10 mol or 20 mol) modified bisphenol A di(meth)acrylate, ethoxylated (30) bisphenol A di(meth)acrylate, di(meth)acrylate of ethylene oxide adduct of bisphenol A, di(meth)acrylate of ethylene oxide adduct of bisphenol F, di(meth)acrylate of ethylene oxide adduct of bisphenol S, di(meth)acrylate of ethylene oxide adduct of thiobisphenol, and di(meth)acrylate of ethylene oxide adduct of brominated bisphenol A. Di(meth)acrylates of bisphenol epoxy alkane adducts such as (meth)acrylates, di(meth)acrylates of diethylene glycol, di(meth)acrylates of triethylene glycol, di(meth)acrylates of tetraethylene glycol, di(meth)acrylates of polyethylene glycol (400) di(meth)acrylates, di(meth)acrylates of polyethylene glycol (600) diacrylates, di(meth)acrylates of dipropylene glycol, di(meth)acrylates of tripropylene glycol, di(meth)acrylates of propylene glycol, di(meth)acrylates of alkoxylated hexanediol diacrylates, di(meth)acrylates of neopentyl glycol hydroxypentanoate, etc.

[0035] As the ether-containing poly(meth)acrylate compound, neopentyl glycol PO-modified diacrylate ((PO)NPGDA), alkoxylated neopentyl glycol di(meth)acrylate or dipropylene glycol diacrylate (DPGDA), ethoxylated (3)trimethylolpropane tri(meth)acrylate, ethoxylated (6)trimethylolpropane tri(meth)acrylate, ethoxylated (9)trimethylolpropane tri(meth)acrylate, propoxylated... (3) Trimethylolpropane tri(meth)acrylate, ethylene oxide modified trimethylolpropane tri(meth)acrylate, ethylene oxide modified pentaerythritol tetra(meth)acrylate, ethylene oxide modified dipentaerythritol penta(meth)acrylate, ethylene oxide modified dipentaerythritol hexa(meth)acrylate, caprolactam modified dipentaerythritol hexa(meth)acrylate, pentaerythritol ethoxytetraacrylate, alkoxylated tetrahydrofurfuryl acrylate, etc.

[0036] (Polyvinyl compounds containing ether groups)

[0037] Examples include: diethylene glycol divinyl ether, cyclohexanediethanol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane diallyl ether, propylene glycol divinyl ether, hexanediol divinyl ether, etc.

[0038] (Meth)acrylate compounds containing vinyl ether groups)

[0039] Examples of (meth)acrylate compounds containing vinyl ether groups include: 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 1-methyl-3-vinyloxypropyl (meth)acrylate, 1-vinyloxymethylpropyl (meth)acrylate, and 2-methyl-3-vinyloxypropyl (meth)acrylate. Ester, 3-Methyl-3-ethoxypropyl (meth)acrylate, 1,1-dimethyl-2-ethoxyethyl (meth)acrylate, 3-ethoxybutyl (meth)acrylate, 1-methyl-2-ethoxypropyl (meth)acrylate, 2-ethoxybutyl (meth)acrylate, 4-ethoxycyclohexyl (meth)acrylate, 5-ethoxypentyl (meth)acrylate, 6-ethoxyhexyl (meth)acrylate, 4-ethoxymethylcyclohexylmethyl (meth)acrylate, 3-Ethyloxymethylcyclohexyl methacrylate, 2-Ethyloxymethylcyclohexyl methacrylate, etc., ethyleneoxyalkyl methacrylate, p-ethyleneoxymethylphenyl methacrylate, m-ethyleneoxymethylphenyl methacrylate, o-ethyleneoxymethylphenyl methacrylate, ethyleneoxyethoxyethyl methacrylate, 2-(ethyleneoxyisopropoxy)ethyl methacrylate, 2-(ethyleneoxyethoxy)propyl methacrylate, 2-(ethyleneoxyethoxy)isopropyl methacrylate, 2-(ethyleneoxyethoxy)propyl methacrylate, 2-(ethyleneoxyisopropoxy)isopropyl methacrylate, 2-(ethyleneoxyethoxyethoxy)ethyl methacrylate, 2-(ethyleneoxyethoxyisopropoxy)ethyl methacrylate, 2-(ethyleneoxyisopropoxy)ethyl methacrylate, 2-(ethyleneoxyisopropoxy)ethyl methacrylate, 2-(ethyleneoxyisopropoxy)ethyl methacrylate, 2-(ethyleneoxyisopropoxy)ethyl methacrylate, etc.

[0040] (Multifunctional monomers with ether bonds)

[0041] Furthermore, in this invention, a poly(meth)acrylate compound containing an ether group is preferably used as the multifunctional monomer having an ether bond.

[0042] In the total amount of polymerizable components, the content of polyfunctional monomers having ether bonds is preferably 5.0% by mass or more, more preferably 10.0% by mass or more, further preferably 13.0% by mass or more, and most preferably 15.0% by mass or more. Furthermore, it is preferably 60.0% by mass or less, more preferably 55.0% by mass or less, further preferably 50.0% by mass or less, and most preferably 45.0% by mass or less.

[0043] (C) Amine-modified oligomers

[0044] The active energy ray curable inkjet ink composition of the present invention contains an amine-modified oligomer as a photopolymerizable compound. There are no particular limitations on the amine-modified oligomer, as long as it is an amine-modified oligomer having at least one amino group and at least one (meth)acryloyl group in its molecule.

[0045] Furthermore, the aforementioned amine-modified (meth)acrylate oligomers are not particularly limited as long as they are polyfunctional amine-modified (meth)acrylate oligomers having two or more (meth)acryloyl groups in their molecules; preferably, they have two or more but six or less, and more preferably two or more but four or less. When the number of (meth)acryloyl groups is two or more but six or less, the polyfunctional amine-modified (meth)acrylate oligomers readily react with polymerizable compounds, and the viscosity of the active energy radiation-curable inkjet ink composition is also easily adjusted to an appropriate range.

[0046] Polyfunctional amine-modified (meth)acrylate oligomers can be synthetic products obtained by polymerizing desired monomers, or they can be commercially available products. Examples include: GENOMER5161, GENOMER5275 (RAHN), CN371, CN371NS, CN373, CN383, CN384, CN386, CN501, CN503, CN550, CN551 (Sartomer), EBECRYL80, EBECRYL81, EBECRYL83, EBECRYL7100, EBECRYL84, EBECRYLP115 (Daicel Allnex), LAROMER PO 83F, LAROMER PO 84F, Laromer LR8946, Laromer LR8956, Laromer LR8996, Laromer LR8894 (BASF), AgiSyn001, AgiSyn002, Agisyn003, Agisyn008 (DSMCoating). (Resin, Inc.), Photomer4771, Photomer4775, Photomer4967, Photomer5096, Photomer5662, Photomer5930 (Cognis, Inc.), DoublecureEPD, DoublecureOPD, Doublecure115, Doublecure225, Doublecure645, PolyQ222, PolyQ226, PolyQ224, PolyQ101 (DoubleBond Chemicals, Inc.). Among these, oligomers having two photopolymerizable functional groups within the molecule are preferred, and (meth)acryloyl group is more preferred.

[0047] The polyfunctional amine-modified (meth)acrylate oligomers used in this invention contain 10.0 to 50.0% by mass in the total amount of polymerizable components in the active energy radiation-curable inkjet ink composition. Preferably, it is 12.0% by mass or more, more preferably 15.0% by mass or more, further preferably 18.0% by mass or more, and most preferably 20.0% by mass or more. Furthermore, it is preferably 45.0% by mass or less, more preferably 42.0% by mass or less, further preferably 40.0% by mass or less, and most preferably 38.0% by mass or less. If it is less than 10.0% by mass, sufficient curability cannot be achieved, and it is difficult to control the viscosity of the active energy radiation-curable inkjet ink composition within an appropriate range. If it exceeds 50.0% by mass, sufficient curability cannot be achieved.

[0048] The following describes photopolymerizable components other than those listed in (A) to (C) above, and which may be included without impairing the effects of the present invention. In particular, the more low molecular weight substances are contained, the easier it is for them to migrate after printing.

[0049] (Other monofunctional photopolymerizable components)

[0050] Other monofunctional photopolymerizable components include, for example, the following compounds.

[0051] (Monofunctional (meth)acrylate alkyl esters)

[0052] Examples of monofunctional (meth)acrylate alkyl esters include: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isoamyl methacrylate, octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, isodecyl methacrylate, tridecyl methacrylate, isomyristyl methacrylate, and so on. Alkyl methacrylates such as octadecyl methacrylate, isooctadecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, butylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, isobornyl methacrylate, adamantyl methacrylate, dicyclopentyl methacrylate, dicyclopentenyl methacrylate, tert-butylcyclohexyl methacrylate, etc., containing cyclic hydrocarbon groups.

[0053] Furthermore, the total amount of polymerizable components in this invention may contain 12.0% by mass or less of the monofunctional (meth)acrylate alkyl ester. Preferably, it is 5.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less.

[0054] (Monofunctional (meth)acrylates with ether bonds)

[0055] Examples include: alkoxyalkyl methacrylates such as ethylcarbidol (meth)acrylate, ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, and butoxyethyl (meth)acrylate.

[0056] Polyalkylene glycol monoalkyl ethers of 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethylhexyl-diethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, caprolactone (meth)acrylate, methoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, butoxytriethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, etc.

[0057] Phenoxy hexaethylene glycol (meth)acrylate, phenoxy diethylene glycol (meth)acrylate, etc., polyalkylene glycol monoaryl ethers (meth)acrylate, tetrahydrofurfuryl methacrylate, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl methacrylate, (3-ethyloxetane-3-yl)methyl methacrylate, caprolactone-modified tetrahydrofurfuryl methacrylate, cyclotrimethylolpropane methyl acetal (meth)acrylate, etc., and other heterocyclic (meth)acrylates.

[0058] 2-Hydroxy-3-phenoxypropyl (meth)acrylate, ethoxyphenyl (meth)acrylate (EO2 mol), ethoxyphenyl (meth)acrylate (EO1 mol), 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, lactone-modified flexible (meth)acrylate, EO (epoxy) Ethane-modified succinic acid (meth)acrylate, methylphenoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate and its ethylene oxide modified derivatives, 2-ethylhexyl carbitol (meth)acrylate, 2-ethylhexyl EO-modified (meth)acrylate, o-phenylphenol EO-modified acrylate, p-cumylphenol EO-modified (meth)acrylate, nonylphenol EO-modified (meth)acrylate, etc., and (poly)alkylene glycol-modified (meth)acrylates, etc.

[0059] (Other monofunctional photopolymerizable monomers)

[0060] Examples include: acryloylmorpholine, N-vinylcaprolactam, acrylamide, acrylonitrile, (meth)acrylamide, N-methoxymethylacrylamide, diacetone acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, hydroxymethyl(meth)acrylamide, di(2-hydroxyethyl)(meth)acrylamide, di(3-hydroxypropyl)(meth)acrylamide, di(4-hydroxybutyl)(meth)acrylamide, and other N-hydroxyalkyl (C1-5)(meth)acrylamides, as well as these N-hydroxyalkyl (C1-5)(meth)acrylamides. Compounds of acrylamide, 1-3 molar adducts of ethylene oxide or propylene oxide, etc., monofunctional monomers with amide structures, such as N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, vinylmethyloxazolidinone, (meth)acryloylpyrrolidone, (meth)acryloylpiperidine, lactone-modified flexible acrylates, etc., nitrogen-containing monomers, such as styrene, (meth)acrylic acid, vinyl acetate, polyurethane (meth)acrylate, epoxy (meth)acrylate, benzyl (meth)acrylate, 2-methacryloyloxyethyl hexahydrophthalic acid, etc.

[0061] (Other multifunctional photopolymerizable components)

[0062] (Multifunctional monomers without ether bonds)

[0063] Examples include: ethylene glycol dimethacrylate, propylene glycol dimethacrylate, cyclohexanediethanol dimethacrylate, dicyclopentyl dimethacrylate, dimethylol octane dimethacrylate, dimethylol tricyclodecane dimethacrylate, dimethylol propane dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-dimethyl-2,4-pentanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,5-dimethyl-2,5-hexanediol dimethacrylate, 1,5-pentanediol dimethacrylate, pentanediol dimethacrylate, neopentanediol dimethacrylate... Methacrylates, 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, 1,10-decanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)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-1,3-pentanediol di(meth)acrylate, 2-Ethyl-1,3-hexanediol di(meth)acrylate Acrylates, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, 2-methyl-1,3-butanediol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dihydroxymethyl dicyclopentane di(meth)acrylate, etc., alkylene glycol di(meth)acrylates, pentaerythritol di(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, pentaerythritol di(meth)acrylate monobenzoate, glycerol di(meth)acrylate, 2-hydroxy-1,The monomers include alkylene polyol poly(meth)acrylates such as 3-di(meth)acryloyloxypropane, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, as well as ether-free polyfunctional (meth)acrylate monomers such as tricyclodecane dimethylol dicaprolactone di(meth)acrylate. Alkylene diol di(meth)acrylates are preferred.

[0064] (Non-amine modified oligomers)

[0065] As a non-amine modified oligomer, it may contain epoxy (meth)acrylate oligomers.

[0066] Epoxy (meth)acrylate oligomers can be synthetic products obtained by polymerizing desired monomers, or they can be commercially available products. Examples include: EBECRYL3708, EBECRYL1606 (Daicel Sitech), CN116, CN120B60, CN120M50, CN131B, CN132, CN137, CN152, CN153, CN2102E, and CN2003 (Sartomer).

[0067] (D) Polymerization initiator

[0068] The active energy X-ray curable inkjet ink composition of the present invention contains ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate (TPO-L) as a photopolymerization initiator. Furthermore, it is preferably contained in 1.0 to 10.0 parts by mass relative to 100 parts by mass of the total polymerizable components of the active energy X-ray curable inkjet ink composition.

[0069] In addition, it may also contain bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819). Furthermore, it is preferably contained in 1.0 to 10.0 parts by weight relative to 100 parts by weight of the total polymerizable components in the active energy ray curable inkjet ink composition.

[0070] In addition, it may contain 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO), or it may not contain it.

[0071] (Other photopolymerization initiators)

[0072] The active energy ray curable inkjet ink composition of the present invention may contain photopolymerization initiators other than those described above, to the extent that the effects of the present invention are not impaired. There are no particular limitations on the photopolymerization initiator, as long as it is a substance that can be polymerized by receiving active energy rays; any photopolymerization initiator suitable for use in active energy ray curable inkjet ink compositions may be used.

[0073] Examples of photopolymerization initiators include: benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ol ketone-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanone-based photopolymerization initiators, triazine-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators. Among these, triazine-based photopolymerization initiators and acylphosphine oxide-based photopolymerization initiators are preferred from the perspective of good curing properties for light-emitting diodes (LEDs). The aforementioned photopolymerization initiators can be used alone or in combination of two or more.

[0074] Examples of photopolymerization initiators include: ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzophenone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropane-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1- Hydroxycyclohexylphenyl ketone, bis-2,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-benzyl-2-dimethylamino-1-(morpholinylphenyl)-butane-1-one, etc.

[0075] (E) Polymer sensitizers

[0076] This invention uses polymeric sensitizers. Examples of thioxanthone-based or acylphosphine-based polymeric sensitizers include Omnipol-TX ((2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester) (number average molecular weight: 660) (manufactured by IGM Resins BV), SpeedCure 7010 (molecular weight 1839) (manufactured by Lambson), and Genopol TX-1 (number average molecular weight: 820) (manufactured by RaHN), etc. Further examples include oligomers (2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)acetone) (manufactured by Lambert, "ESACURE KIP"). 150", "ESACURE1", polyethylene glycol 200-bis(β-4-(4-(2-dimethylamino-2-benzyl)butyrylphenyl)piperazine) (manufactured by IGM, "Omnipol 910"), (carboxymethoxymethoxybenzophenone)-(polyethylene glycol 250) diester (manufactured by IGM, "Omnipol BP"), etc. These can be used alone or in combination.

[0077] In this invention, by including a polymeric sensitizer, curability can be improved, and by making the polymeric sensitizer difficult to migrate, the residual volatile or migrating components after curing can be reduced.

[0078] The polymer sensitizer is preferably contained in 0.5 to 10.0 parts by weight of 100 parts by weight of total polymerizable components in the active energy radiation curable inkjet ink composition. More preferably, it contains 1.0 parts by weight or more; further preferably, 1.5 parts by weight or more; most preferably, 2.0 parts by weight or more; more preferably, 6.0 parts by weight or less; further preferably, 4.0 parts by weight or less; and most preferably, 3.5 parts by weight or less.

[0079] (Other sensitizers)

[0080] From the perspective of improving curability, without compromising the effects of the present invention, the active energy ray curable inkjet ink composition of the present invention may contain other sensitizers. The aforementioned sensitizers may be used alone or in combination of two or more.

[0081] Other sensitizers are not specifically limited, but may include thioxanthones, benzophenones such as 4,4'-bis(diethylamino)benzophenone, anthraquinones, and coumarins. In particular, thioxanthone compounds such as 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone-9-one, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone, or anthracene compounds such as 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, and 9,10-bis(2-ethylhexyloxy)anthracene, as well as 4,4'-dialkylaminobenzophenones such as michidone and 4,4'-bis-(diethylamino)benzophenone, are examples.

[0082] (pigment)

[0083] The active energy ray curable ink composition for inkjet printing of the present invention may contain any pigment.

[0084] The pigment is a variety of organic and inorganic pigments that can be used in inkjet ink compositions.

[0085] Examples of the aforementioned organic pigments include: lake pigments, azo pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perylene pigments, violet ketone pigments, pyrrolopyrroledione pigments, isoindolinone pigments, nitro pigments, nitroso pigments, anthraquinone pigments, yellow anthraquinone pigments, quinophthalone pigments, pinantrone pigments, and indigoantrone pigments. Examples of the aforementioned inorganic pigments include: carbon black, titanium dioxide, zinc white, iron oxide red, lead black, iron black, chromium oxide green, and aluminum hydroxide. These pigments can be substances that have undergone surface treatment using known surface treatment agents.

[0086] The following substances can be listed as specific examples of the representative hues of the aforementioned pigments.

[0087] Examples of yellow pigments include CI pigments 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, and 213.

[0088] Examples of magenta pigments include CI pigments 5, 7, 12, 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, and 270.

[0089] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 22, 27, 29, 60, etc.

[0090] Examples of orange pigments include CI pigments Orange 1, 2, 3, 4, 5, 13, 15, 16, 17, 19, 24, 31, 34, 36, 38, 40, 43, 46, 48, 49, 51, 60, 61, 62, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 81, etc.

[0091] Examples of purple pigments include CI pigments 1, 2, 3, 3:1, 3:3, 5:1, 13, 17, 19, 23, 25, 27, 29, 31, 32, 36, 37, 38, 42, and 50.

[0092] Examples of black pigments include carbon black (CI Pigment Black 7).

[0093] As white pigments, examples include titanium dioxide and aluminum oxide, which can be surface-treated with various materials such as aluminum oxide and silicon dioxide.

[0094] (Pigment dispersant)

[0095] In the active energy ray curable ink composition of the present invention, a pigment dispersant is preferably used.

[0096] The aforementioned pigment dispersants are used to improve the dispersibility of pigments and the storage stability of active energy ray curable inkjet ink compositions. Conventionally used substances can be used without particular restrictions, with polymeric pigment dispersants being preferred. Two or more of the aforementioned pigment dispersants can be used alone or in combination.

[0097] Examples of dispersants for the aforementioned polymeric pigments include carbodiimide dispersants, polyester amine dispersants, fatty acid amine dispersants, modified polyacrylate dispersants, modified polyurethane dispersants, multi-chain polymeric nonionic dispersants, and polymeric ionic dispersants.

[0098] Examples of such polymeric pigment dispersants include BYKJET-9150, BYKJET-9151, BYKJET-9170, DISPERBYK-168, DISPERBYK-190, DISPERBYK-198, DISPERBYK-2010, DISPERBYK-2012, and DISPERBYK-2015 (BYK Chemie, SMA1440, SMA2625, SMA17352, SMA3840, SMA1000, SMA2000, SMA3000 (CrayValley), JONCRYL67, JONCRYL678, JONCRYL586, JONCRYL611, JONCRYL680, JONCRYL682, JONCRYL690, JONCRYL819, JONCRYL-JDX5050, EFKA4550, EFKA4560, EFKA4585, EFKA 4701, EFKA5220, EFKA6230 (BASF), SOLSPERSE20000, SOLSPERSE27000, SOLSPERSE36000, SOLSPERSE41000, SOLSPERSE41090, SOLSPERSE43000, SOLSPERSE44000, SOLSPERSE46000, SOLSPERSE47000, SOLSPERSE54000, SOLSPERSE56000 (LUBRIZOL), AJISPER PB821, AJISPER PB822, AJISPER PB824, AJISPERPB881 (Ajinomoto Fine Technology Co., Ltd.), etc.

[0099] From the perspective of improving the dispersibility of pigments and the storage stability of active energy ray curable inkjet ink compositions, the content of pigment dispersant relative to the total mass of pigments is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, and further preferably 100% by mass or less, more preferably 60.0% by mass or less.

[0100] (surfactant)

[0101] In the active energy ray curable inkjet ink composition of the present invention, known surfactants suitable for use in active energy ray curable inkjet ink compositions can be used without particular limitation, depending on the inkjet head used. Examples include nonionic surfactants, cationic surfactants, anionic surfactants, and betaine surfactants. Specific examples of the aforementioned surfactants include organosilicon surfactants such as polyether-modified silicone oil, polyester-modified polydimethylsiloxane, and polyester-modified methylalkyl polysiloxane, as well as fluorinated surfactants and acetylene surfactants. Two or more of the aforementioned surfactants can be used alone or in combination.

[0102] Examples of the aforementioned organosilicon surfactants include BYK-307, BYK-315N, BYK-331, BYK-333, BYK-347, BYK-348, BYK-349, BYK-345, BYK-377, BYK-378, and BYK-3455 (BYK Chemie).

[0103] Examples of fluorinated surfactants mentioned above include F-410, F-444, F-553 (DIC), FS-65, FS-34, FS-35, FS-31, and FS-30 (DuPont).

[0104] Examples of acetylene surfactants mentioned above include DYNOL 607, DYNOL 609, OLFINE E1004, OLFINE E1010, OLFINE E1020, OLFINE PD-001, OLFINE PD-002W, OLFINE PD-004, OLFINE PD-005, OLFINE EXP.4001, OLFINE EXP.4200, OLFINE EXP.4123, and OLFINE... EXP.4300 (Nikshin Chemical Co., Ltd.), SURFYNOL104E, SURFYNOL104H, SURFYNOL104A, SURFYNOL104BC, SURFYNOL104DPM, SURFYNOL104PA, SURFYNOL104PG-50, SURFYNOL420, SURFYNOL440, SURFYNOL465 (EVONIK Co., Ltd.), etc.

[0105] In the active energy ray curable inkjet ink composition of the present invention, from the perspective of reducing the surface tension of the ink composition and improving the ejection stability from the inkjet head, the proportion of the aforementioned surfactant is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and from the perspective of suppressing foam in the ink composition generated during the mixing process and improving ejection stability, it is preferably 1.5% by mass or less, more preferably 1% by mass or less.

[0106] (solvent)

[0107] The active energy ray curable inkjet ink composition of the present invention is solvent-free, but solvents can be formulated as needed. Examples of such solvents include ester organic solvents, ether organic solvents, ether ester organic solvents, ketone organic solvents, aromatic hydrocarbon solvents, and nitrogen-containing organic solvents. Furthermore, substances with a boiling point of 150-220°C at 1 atmosphere can be included as solvents. From the perspective of the curability of the ink composition and environmental concerns, it is preferable to avoid using the aforementioned solvents as much as possible. The proportion of the aforementioned solvents in the ink composition is preferably 5% by mass or less, more preferably 2% by mass or less.

[0108] <Additives>

[0109] To achieve various functionalities, the active energy ray curable ink composition of the present invention can be supplemented with various additives as needed. Specifically, examples include surfactants, surface conditioners, light stabilizers, ultraviolet absorbers, surface treatment agents, preservation improvers, antioxidants, anti-aging agents, crosslinking accelerators, polymerization inhibitors, plasticizers, mildew inhibitors, preservatives, pH adjusters, defoamers, humectants, rust inhibitors, and thickeners. Furthermore, a non-curable resin that functions as a color carrier can be formulated, or it may not be formulated. Additionally, it may or may not contain a solvent.

[0110] (Surface Conditioner)

[0111] When surface modifiers are included, the content of surface modifiers is not particularly limited, but preferably the content is such that the surface tension of the active energy ray curable inkjet ink composition reaches 22.0 to 30.0 mN / m, and more preferably 0.10 to 1.50 by mass in the active energy ray curable inkjet ink composition.

[0112] (Preservative improver)

[0113] As a preservation improver, hindered amines such as N-CH3 type, NH type, and N-OR type can be used.

[0114] (UV absorber)

[0115] Ultraviolet absorbers include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylates, hydroxyphenyltriazine-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, nickel complex-based ultraviolet absorbers, etc.

[0116] (Antioxidants)

[0117] Antioxidants include phenolic antioxidants, amine antioxidants, sulfur antioxidants, and phosphorus antioxidants.

[0118] (Defoamer)

[0119] The defoamers include silicone defoamers, Pluronic (registered trademark) defoamers, etc.

[0120] The active energy ray curable ink composition of the present invention preferably has a viscosity of 30.0 cps or more at 45°C, more preferably 35.0 cps or more, more preferably 38.0 cps or more, even more preferably 40.0 cps or more, and most preferably 50.0 cps or more. Furthermore, it is preferably 1000.0 cps or less, more preferably 100.0 cps or less, even more preferably 80.0 cps or less, and most preferably 60.0 cps or less.

[0121] Furthermore, the viscosity at 80°C is preferably 6.0 cps or higher, more preferably 6.5 cps or higher, even more preferably 7.0 cps or higher, and most preferably 7.5 cps or higher. Additionally, it is preferably 15.0 cps or lower, more preferably 12.0 cps or lower, even more preferably 11.0 cps or lower, and most preferably 10.0 cps or lower.

[0122] Furthermore, viscosity modifiers may be added to the ink composition as needed. Additionally, the viscosity described in this application specification is the viscosity measured using an E-type viscometer (RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.) at 45°C and 80°C, and 20 rpm.

[0123] <Preparation Method of Active Energy Ray Curable Ink Composition for Inkjet Printing>

[0124] Next, a method for manufacturing the active energy ray curable inkjet ink composition of the present invention using these materials will be described.

[0125] The active energy radiation-curable inkjet ink composition of the present invention can be obtained by dispersing and mixing the components using, for example, a wet circulating mill, bead mill, ball mill, sand mill, vertical ball mill (attritor), roller mill, DCP mill, mixer, Henschel mixer, colloid mill, ultrasonic homogenizer, high-pressure homogenizer (Micro fluidizer, Nanomizer, Ultimizer, GenusPY, DeBEE2000, etc.), pearl mill, etc., and adjusting the viscosity of the active energy radiation-curable inkjet ink composition as needed. Alternatively, the active energy radiation-curable inkjet ink composition can also be prepared by mixing pigments, the aforementioned pigment dispersant, and the aforementioned photopolymerizable monomers to obtain a base ink composition in advance, and then adding the remaining portion of the aforementioned components to achieve the desired composition.

[0126] <Printing Methods>

[0127] A printing method for an ink composition for an active energy ray curable inkjet printer based on the present invention will be described.

[0128] The inkjet printing apparatus used is not particularly limited as long as it has a mechanism for heating the ink composition to a specified temperature. Examples include providing an active energy ray curable inkjet ink composition to the printhead of an inkjet recording printing apparatus, ejecting the ink composition from the printhead onto the substrate to be printed, and then curing the ink composition by exposing it to an active energy ray. Examples of active energy rays include ultraviolet light emitted from light-emitting diodes (LEDs) or various lamps or electrodes, electron beams, and visible light. Curing performance is particularly excellent for ultraviolet light using LEDs as a light source.

[0129] During printing, the heating temperature of the ink composition is preferably set to 50~90°C by the heating mechanism described above.

[0130] By using an inkjet printing device, materials that are difficult to migrate (i.e., materials with high molecular weight or that easily interact through polar groups) can be selected by ejecting them at high temperature when they are ejected from the printhead.

[0131] Furthermore, there are no particular limitations on the substrate. Any substrate suitable for conventionally known active energy ray curable inkjet ink compositions is acceptable. Examples of such substrates include: plastics, paper, capsules, gels, metal foils, glass, wood, and cloth. Examples of such plastics include: polycarbonate, rigid polyvinyl chloride, flexible polyvinyl chloride, ABS, polyethylene terephthalate, polyesters, polypropylene, acrylic resins, and polystyrene.

[0132] Specifically, one method for printing and curing the ink composition of the present invention can be described as follows: after the ink composition of the present invention is sprayed onto a substrate by an inkjet head, the coating of the ink composition of the present invention on the substrate is exposed to light and then cured.

[0133] For example, the ejection onto the substrate (image printing) can be performed by supplying the ink composition of the present invention to the print head via the heating device of an inkjet printer, and ejecting the ink composition from the print head with a coating thickness of, for example, 1 to 60 μm relative to the substrate. Furthermore, light exposure and curing (image curing) can be performed by irradiating the coating of the ink composition of the present invention, which is coated onto the substrate as an image, with light.

[0134] As a printing apparatus for printing the ink composition of the present invention using an inkjet recording method, conventional inkjet recording method printing apparatuses can be used. Furthermore, when using a continuous inkjet recording method printing apparatus, a conductive agent is further added to the ink composition of the present invention to adjust the conductivity.

[0135] As a light source for curing the above-mentioned coating, examples include ultraviolet light (UV lamp), ultraviolet light (light-emitting diode (LED)), electron beams, visible light, etc. From an environmental perspective, it is preferable to use a light-emitting diode (LED) that produces ultraviolet light with a peak emission wavelength in the range of 350~420nm.

[0136] Example

[0137] The following examples illustrate the present invention in more detail, but the present invention is not limited to these examples.

[0138] Active energy ray curable inkjet ink compositions were prepared for each of the examples and comparative examples described in Table 1 below. The test results and properties of each active energy ray curable inkjet ink composition are shown in Table 1.

[0139] PY150: Pigment Yellow 150

[0140] PR122: Pigment Red 122

[0141] PR254: Pigment Red 254

[0142] PB15:4: Pigment Blue 15:4

[0143] P.Bk.7: Carbon Black

[0144] S56000: Water-soluble polymeric dispersant (SOLSPERSES 56000, LUBRIZOL Corporation, Japan)

[0145] BYKJET9151: Water-soluble polymeric dispersant (BYKJET-9151, BYK Corporation)

[0146] S36000: Water-soluble polymeric dispersant (SOLSPERSES 36000, LUBRIZOL Corporation, Japan)

[0147] CN371NS: Amine-modified (meth)acrylate oligomer (“Sartomer CN371NS”, Sartamomer Arkema)

[0148] CN373: Amine-modified (meth)acrylate oligomers (Sartomer Arkema)

[0149] Agisyn008: Amine-modified (meth)acrylate oligomers (DSM-Agi)

[0150] Agisyn003: Amine-modified (meth)acrylate oligomer (DSM-Agi)

[0151] (PO)NPGDA: Neopentyl glycol PO-modified diacrylate

[0152] DPGDA: Dipropylene glycol diacrylate

[0153] TPO: Photopolymerization initiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide

[0154] TPO-L: Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphonate, a photopolymerization initiator

[0155] Omnirad 819: Photopolymerization initiator bis(2,4,6-trimethylbenzoyl)phenoxyphosphine oxide (IGMResins BV)

[0156] OmnipolTX: Polymer sensitizer (2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester (IGM Resins BV)

[0157] UV22: Quinone polymerization inhibitor (BASF)

[0158] BYK-377: Silicon-based surface conditioner (BYK Chemie)

[0159] (Viscosity)

[0160] The viscosity (cps) of the active energy ray curable inkjet ink compositions obtained in the examples and comparative examples was measured using an E-type viscometer (trade name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.) at temperatures of 45°C and 80°C and a rotor speed of 20 rpm.

[0161] (Seamless fit)

[0162] Using a #4 doctor blade coater at 25°C, the active energy X-ray curable inkjet ink compositions obtained in the examples and comparative examples were coated onto PET (polyethylene terephthalate) films (Lumirror (Toray Industries)) and PP (polypropylene) films (YUPO80 (UV) PA-T1 (YUPO Corporation)). Then, a UV-LED lamp manufactured by Phoseon Technology was used, with a distance of 2 cm between the lamp and the ink coating surface, and an irradiation time of 1 second per session (cumulative UV light intensity of 60 mJ / cm² per second). 2 Under the conditions described above, the coating is irradiated twice to form a cured film.

[0163] The cured coating surface is cross-cut with a cutting tool to create 100 small square pieces of cured coating. Transparent tape (manufactured by NICHIBAN, trade name: Cellotape) is applied to the cut sections, then peeled off. The number of square pieces that were not adhered to the transparent tape and were peeled off, leaving them on the substrate, is counted. For example, 100 / 100 means that none were peeled off, and all pieces remained on the substrate; 20 / 100 means that 20 pieces remained on the substrate, and 80 pieces were adhered to the transparent tape and peeled off.

[0164] (LED curability)

[0165] The inkjet recording device and the active energy radiation-curable inkjet ink composition were placed at an ambient temperature of 25°C for 24 hours to bring the temperature of the inkjet recording device and the ink composition to 25°C. Then, at 25°C, the active energy radiation-curable inkjet ink composition was coated onto PVC80 (manufactured by LINTEC).

[0166] Next, a UV-LED lamp manufactured by Phoseon Technology was used, with a distance of 2 cm between the lamp and the ink coating surface, and an irradiation time of 1 second per session (cumulative UV light intensity of 60 mJ / cm² per second). 2 The number of irradiations required until the surface adhesiveness disappears is used for evaluation.

[0167] The number of irradiations is shown in Table 1. (One irradiation is indicated by "○", and two or more irradiations are indicated by "×".)

[0168] (Migration test)

[0169] Printing conditions: Printed on PP film (trade name "P-2161", Toyobo Co., Ltd.) using a single-pass printer at a printing speed of 48m / min, followed by curing by LED irradiation (irradiation energy 500mJ). The resulting printed material was cut into 13mm×13mm pieces.

[0170] The film was placed in approximately 200 mL of a 50% ethanol aqueous solution and stored at 40°C for 10 days.

[0171] After standing, the ethanol-water solution was recovered and an internal standard solution was added.

[0172] Pass the recovered ethanol-water solution through a solid-phase extraction column and elute the retained components with 1 ml of methanol (concentrated to 200 times).

[0173] The resulting solution was analyzed by gas chromatography-mass spectrometry (GC / MS) to determine the amount of coating migration. This measurement was used to confirm the migration trend.

[0174] [Table 1]

[0175]

[0176] According to examples of the present invention, namely the various embodiments, the ink composition for active energy ray curable inkjet printing has a suitable viscosity range at 80°C, exhibiting excellent adhesion to various substrates and LED curability. Furthermore, the amount of coating migration is also extremely low.

[0177] In contrast, according to Comparative Examples 1 and 2, which do not contain (B) polyfunctional monomers with ether bonds, and Comparative Example 5, which does not contain ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate, the amount of migration in the coating film is extremely high.

[0178] In addition, according to Comparative Examples 3 and 4, which contain isoborneol acrylate or benzyl acrylate, a large amount of migration was also generated.

[0179] According to Comparative Example 6, which does not contain polymeric sensitizers, and Comparative Example 7, which has a low content of amine-modified oligomers, the LED curability is poor.

Claims

1. An ink composition for inkjet printing that is cured by active energy rays, characterized in that, All of the following conditions (A) to (E) must be satisfied: (A) The total amount of polymerizable components contains 20.0 to 60.0% by mass of hydroxyl-containing monofunctional (meth)acrylates. (B) Contains polyfunctional monomers with ether bonds. (C) The total amount of polymerizable components contains 10.0 to 50.0% by mass of an amine-modified oligomer, wherein the amine-modified oligomer is an amine-modified oligomer having at least one amino group and at least one (meth)acryloyl group in its molecule. (D) As a polymerization initiator, it contains ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate. (E) Contains a high molecular weight sensitizer.

2. The active energy ray curable ink composition for inkjet printing according to claim 1, characterized in that, The polymeric sensitizer is a thioxanthone compound.

3. The active energy ray curable ink composition for inkjet printing according to claim 1 or 2, characterized in that, The ink composition for inkjet printing, relative to 100 parts by weight of the total polymerizable components, further contains 1.0 to 10.0 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

4. The active energy ray curable ink composition for inkjet printing according to claim 1, characterized in that, The ink composition for inkjet printing that is cured by active energy rays contains 1.0 to 10.0 parts by mass of ethyl phenyl (2,4,6-trimethylbenzoyl)phosphonate, relative to 100 parts by mass of the total polymerizable components.

5. The active energy ray curable ink composition for inkjet printing according to claim 1 or 2, characterized in that, The polymeric sensitizer is (2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester.

6. The active energy ray curable ink composition for inkjet printing according to claim 1, characterized in that, Further, the following condition (F) must be met: the viscosity of the active energy ray curable inkjet ink composition is 38.0 cps or more at 45°C and 15 cps or less at 80°C.

7. The active energy ray curable ink composition for inkjet printing according to claim 1, characterized in that, Contains polyfunctional monomers without ether bonds and / or monofunctional (meth)acrylate alkyl esters.

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