Active energy ray-curable inkjet ink composition

Abstract

The object of the present invention is to obtain an active energy ray-curable inkjet ink composition, which can form a film with excellent adhesion to various substrates, can be cured by LED, and the cured film has high hardness, excellent abrasion resistance and water resistance. As a solution, an active energy ray-curable inkjet ink composition is provided, characterized in that it satisfies all of the following conditions (A) to (F): (A) the total amount of the total polymerizable components contains 0.2 to 14.0 mass % of a polyfunctional amine-modified oligomer; (B) the total amount of the total polymerizable components contains 50.0 mass % or more of a monofunctional monomer; (C) the total amount of the total polymerizable components contains 30.0 mass % or more of a monofunctional monomer with a glass transition temperature of 20°C or more; (D) the total amount of the total polymerizable components contains 20.0 mass % or more of a monofunctional monomer with a glass transition temperature of 10°C or less; (E) the total amount of the total polymerizable components contains 3.0 to 12.0 mass % of a monofunctional monomer with a glass transition temperature of 10°C or less. ℃ or less; (F) the total amount of the total polymerizable components contains 30.0 to 50.0 mass % of nitrogen-containing monofunctional monomers, except for the following cases: A photocurable ink composition for inkjet printing, which satisfies the following conditions A to E: A. the total photopolymerizable compounds contain 5 to 50 mass % of 3,3,5-trimethylcyclohexyl acrylate; B. the total photopolymerizable compounds contain 1 to 15 mass % of multifunctional monomers and / or multifunctional oligomers with a glass transition temperature of 10℃ or less; C. the total photopolymerizable compounds contain more than 40 mass % of monofunctional monomers; D. contain monomers and / or oligomers having amino groups and / or amide groups; E. the viscosity of the ink composition is 10 mPa·s or less at 25℃.

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable inkjet ink composition. Background Art

[0002] As described in Patent Document 1, an active energy ray-curable inkjet printing ink composition containing a monofunctional or polyfunctional photopolymerizable compound and an oligomer is known.

[0003] According to this active energy ray-curable inkjet printing ink composition, excellent effects can be achieved in various aspects such as storage stability, curability, and adhesion. However, it has not been confirmed that it can be used on various substrates, and it has not been studied whether it can be used on other substrates such as polycarbonate and polyvinyl chloride, or whether the hardness, abrasion resistance, and water resistance of the cured coating film can be improved.

[0004] There is no demand for active energy ray-curable inkjet ink compositions that can be used on a wider range of substrate materials, have higher hardness, and have abrasion resistance or water resistance, and for cured films to be used in a wider range.

[0005] Therefore, there is a possibility that it cannot fully cope with the application or use environment of the substrate on which the film is formed using the active energy ray-curable inkjet ink composition.

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-31618 Summary of the invention

[0008] The present invention aims to provide an active energy ray-curable inkjet ink composition which can form a film having excellent adhesion to various substrates, can be cured by LED, and further has a cured film with high hardness and excellent abrasion resistance and water resistance.

[0009] 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.

[0010] That is, the present invention is as follows.

[0011] 1. An active energy ray-curable inkjet ink composition, characterized in that it satisfies all of the following conditions (A) to (F):

[0012] (A) containing 0.2 to 14.0% by mass of a polyfunctional amine-modified oligomer in the total amount of all polymerizable components;

[0013] (B) containing 50.0 mass % or more of a monofunctional monomer in the total amount of all polymerizable components;

[0014] (C) 30.0 mass % or more of a monofunctional monomer having a glass transition temperature of 20° C. or higher is contained in the total amount of all polymerizable components;

[0015] (D) the total amount of all polymerizable components contains 20.0 mass % or more of a monofunctional monomer having a glass transition temperature of 10° C. or less;

[0016] (E) 3.0 to 12.0 mass % of a polyfunctional monomer having a glass transition temperature of 10° C. or less is contained in the total amount of all polymerizable components;

[0017] (F) 30.0 to 50.0 mass % of a nitrogen-containing monofunctional monomer is contained in the total amount of all polymerizable components,

[0018] However, the following are excluded: A photocurable inkjet printing ink composition that satisfies the following conditions A to E:

[0019] A. containing 5 to 50% by mass of 3,3,5-trimethylcyclohexyl acrylate in the total photopolymerizable compound;

[0020] B. containing 1 to 15% by mass of a multifunctional monomer and / or a multifunctional oligomer having a glass transition temperature of 10° C. or less in the total photopolymerizable compound;

[0021] C. containing 40% by mass or more of monofunctional monomers in total in the total photopolymerizable compound;

[0022] D. Containing monomers and / or oligomers having amino groups and / or amide groups;

[0023] E. The viscosity of the ink composition is 10 mPa·s or less at 25°C.

[0024] 2. The active energy ray-curable inkjet ink composition according to 1, wherein the (A) polyfunctional amine-modified oligomer is a bifunctional amine-modified oligomer and has a viscosity at 25° C. of 2000 cps or less.

[0025] 3. The active energy ray-curable inkjet ink composition according to 1 or 2, wherein the nitrogen-containing monofunctional monomer is at least one selected from acryloylmorpholine, vinylmethyloxazolidinone, vinylcaprolactam and N,N-dimethylacrylamide.

[0026] According to the present invention, an active energy ray-curable inkjet ink composition can be obtained, which can form a film with excellent adhesion to various substrates, can be cured by LED, and further the cured film can have high hardness, excellent abrasion resistance and water resistance. DETAILED DESCRIPTION

[0027] The active energy ray-curable inkjet ink composition of the present invention contains a polymerizable component that is cured by irradiation with active energy rays and satisfies the above-mentioned conditions A to F, which are described in order below.

[0028] In addition, a plurality of components contained in each condition are repeatedly included in each condition.

[0029] <A. Polyfunctional amine-modified oligomer>

[0030] The polyfunctional amine-modified oligomer in the present invention is a polyfunctional oligomer having an amino group.

[0031] As such a polyfunctional amine-modified oligomer, CN501, CN503, CN550, CN373, CN383, CN384 and CN371NS manufactured by Sartomer, EBECRYL 80, EBECRYL 81, EBECRYL 83 and EBECRYL 7100 manufactured by Daicel-Allnex, LAROMER PO 83F and LAROMER PO 84F manufactured by BASF, AgiSyn001, AgiSyn002, AgiSyn003, AgiSyn005, AgiSyn006, AgiSyn007 and AgiSyn008 manufactured by DSM-Agi and the like can be used.

[0032] Among them, an oligomer having two photopolymerizable functional groups in the molecule is preferred, and a (meth)acryloyl group is more preferred in which the photopolymerizable functional group is present.

[0033] The content of the polyfunctional amine-modified oligomer is 0.2 to 14.0% by mass in the total amount of the total polymerizable components of the active energy ray-curable inkjet ink composition. Among them, it is preferably 1.0% by mass or more, more preferably 3.0% by mass or more, and further preferably 5.0% by mass or more. In addition, it is preferably 12.0% by mass or less, and more preferably 10.0% by mass or less. If the content is less than 0.2% by mass, the curability and adhesion may be reduced. If the content exceeds 14.0% by mass, the viscosity will become too high.

[0034] The viscosity of the polyfunctional amine-modified oligomer at 25° C. is required to be 2000 cps or less in order to control the viscosity of the entire active energy ray-curable inkjet ink composition within an appropriate range.

[0035] <B. Monofunctional monomer>

[0036] Examples of the monofunctional monomer contained in the active energy ray-curable inkjet ink composition of the present invention include the following compounds.

[0037] Examples thereof include butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, isotetradecyl (meth)acrylate, isomyristyl (meth)acrylate, octadecyl (meth)acrylate, isooctadecyl (meth)acrylate, isobornyl (meth)acrylate, lauryl (meth)acrylate, cyclotrimethylolpropane formal (meth)acrylate, cyclohexyl (meth)acrylate, butylcyclohexyl acrylate, trimethylcyclohexyl acrylate, adamantyl (meth)acrylate, dicyclopentyl (meth)acrylate, acrylic esters of dicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate and ethylene oxide-modified products thereof , ethyl carbitol (meth)acrylate, 2-methoxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, 2-ethylhexyl carbitol (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-ethyl 2-Acryloyloxyethyl hexahydrophthalate, Butoxyethyl acrylate, Ethoxydiethylene glycol (meth)acrylate, Diethylene glycol monoethyl ether (meth)acrylate, Caprolactone (meth)acrylate, Ethyl carbitol (meth)acrylate, Methoxydiethylene glycol (meth)acrylate, Methoxytriethylene glycol (meth)acrylate, 2-ethylhexyl diglycol acrylate, Phenoxydiethylene glycol (meth)acrylate,

[0038] Methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylate (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl ester, acrylate (3-ethyloxetanyl-3-yl)methyl ester, phenol glycol modified acrylate, (meth)acrylate-2-hydroxypropyl ester, ethoxyphenyl acrylate (EO2 mol), ethoxyphenyl acrylate (EO1 mol), succinic acid 2-acryloxyethyl ester, phthalic acid 2-acryloxyethyl-2-hydroxyethyl phthalate, lactone modified flexible acrylate, (meth) acrylate tert-butyl cyclohexyl ester, vinyloxyethoxyethyl (meth) acrylate, EO (ethylene oxide) modified succinic acid (meth) acrylate, cyclotrimethylolpropane formal acrylate, acryloyl morpholine, acrylonitrile, acrylamide, diethylacrylamide, styrene, (meth) acrylic acid, etc.

[0039] This monofunctional monomer is contained in the active energy ray-curable inkjet ink composition specifically for the purpose of lowering the viscosity, and it contains 50.0 mass% or more, preferably 70.0 mass% or more, more preferably 80.0 mass% or more, further preferably 85.0 mass% or more, and most preferably 90.0 mass% or more in the total amount of all polymerizable components in the active energy ray-curable inkjet ink composition.

[0040] Furthermore, it is preferred to contain a monofunctional monomer having an amide structure, and more preferably to contain acryloylmorpholine, vinylcaprolactam, acrylamide, or diethylacrylamide. Dimethylacrylamide may or may not be contained.

[0041] The content of the monofunctional monomer having an amide structure is preferably 20.0% 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, based on the total amount of all polymerizable components in the active energy ray-curable inkjet ink composition. It is also preferably 60.0% by mass or less, more preferably 50.0% by mass or less, further preferably 48.0% by mass or less, and most preferably 46.0% by mass or less.

[0042] Among the monofunctional monomers having an amide structure, it is further preferred to contain acryloylmorpholine. The content of acryloylmorpholine is preferably 5.0% by mass or more, more preferably 10.0% by mass or more, further preferably 15.0% by mass or more, and most preferably 20.0% by mass or more in the total amount of all polymerizable components in the active energy ray-curable inkjet ink composition. In addition, it is preferably 40.0% by mass or less, more preferably 35.0% by mass or less, further preferably 32.0% by mass or less, and most preferably 30.0% by mass or less.

[0043] It is also more preferable that the monofunctional monomer having an amide structure contains vinyl caprolactam. The content of vinyl caprolactam 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 in the total amount of all polymerizable components of the active energy ray-curable inkjet ink composition. In addition, it is preferably 25.0% by mass or less, more preferably 22.0% by mass or less, further preferably 20.0% by mass or less, and most preferably 18.0% by mass or less.

[0044] Furthermore, the mass ratio of acryloylmorpholine to vinylcaprolactam is preferably 1.00 or more, more preferably 1.10 or more, further preferably 1.20 or more, and most preferably 1.30 or more. In addition, it is preferably 2.20 or less, more preferably 2.00 or less, and further preferably 1.80 or less. When the ratio is 1.00 or more, it is easy to further improve the curability on the basis of other excellent effects. When the ratio exceeds 2.20, the viscosity of the active energy ray-curable inkjet ink composition will increase, and it may become difficult to operate.

[0045] <C. Monofunctional monomer having a glass transition temperature of 20°C or higher>

[0046] Among the above monofunctional monomers, a monofunctional monomer having a glass transition temperature of 20° C. or higher is selected, and the amount of the monofunctional monomer in the total amount of the polymerizable components of the active energy ray-curable inkjet ink composition is 30.0% by mass or more. Among them, 35.0% by mass or more is preferred, 38.0% by mass or more is more preferred, 40.0% by mass or more is further preferred, and 45.0% by mass or more is most preferred. In addition, 70.0% by mass or less is preferred, 65.0% by mass or less is more preferred, 60.0% by mass or less is further preferred, and 55.0% by mass or less is most preferred.

[0047] Among the monofunctional monomers having a glass transition temperature of 20° C. or above, the above-mentioned monofunctional monomers having an amide structure and compounds having a cyclic structure are preferred. In addition to the monofunctional monomers having an amide structure, isobornyl (meth)acrylate or cyclotrimethylolpropane formal acrylate is more preferred.

[0048] Furthermore, among the monofunctional monomers having a glass transition temperature of 20° C. or higher, those having a glass transition temperature of 50° C. or higher are preferred, and those having a glass transition temperature of 70° C. or higher are more preferred.

[0049] Here, 3,3,5-trimethylcyclohexyl acrylate may or may not be contained.

[0050] <D. Monofunctional monomer having a glass transition temperature of 10°C or less>

[0051] Among the above monofunctional monomers, a monofunctional monomer having a glass transition temperature of 10° C. or less is selected, and the amount of the monofunctional monomer in the total amount of the polymerizable components of the active energy ray-curable inkjet ink composition is 20.0% by mass or more. Among them, 25.0% by mass or more is preferred, 30.0% by mass or more is more preferred, 33.0% by mass or more is further preferred, and 35.0% by mass or more is most preferred. In addition, 60.0% by mass or less is preferred, 55.0% by mass or less is more preferred, 50.0% by mass or less is further preferred, and 45.0% by mass or less is most preferred.

[0052] Furthermore, among the monofunctional monomers having a glass transition temperature of 10° C. or lower, those having a glass transition temperature of -30° C. or lower are preferred, and those having a glass transition temperature of -50° C. or lower are more preferred.

[0053] <E. Polyfunctional monomer having a glass transition temperature of 10°C or less>

[0054] The polyfunctional monomer having a glass transition temperature of 10° C. or lower is a compound having a plurality of carbon-carbon unsaturated bonds in a molecule, and for example, the following compounds can be used.

[0055] Trimethylolpropane tri(meth)acrylate, dipropylene glycol diacrylate, vinyloxyethoxyethyl (meth)acrylate, ethoxylated (3) trimethylolpropane triacrylate (Tg: -45°C), propoxylated (3) trimethylolpropane triacrylate (Tg: -15°C), EO (10 mol or 20 mol) modified bisphenol A diacrylate, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) diacrylate, alkoxylated hexanediol diacrylate.

[0056] The active energy ray-curable inkjet ink composition contains 3.0% by mass or more of a multifunctional monomer having a glass transition temperature of 10° C. or less in the total amount of all polymerizable components. The amount may be 5.0% by mass or more, or 7.0% by mass or more. The amount may be 12.0% by mass or less, or 11.0% by mass or less, or 9.0% by mass or less.

[0057] When the content of the polyfunctional monomer having a glass transition temperature of 10° C. or less is less than 3.0% by mass, the coating film does not harden, and pencil hardness, abrasion resistance and water resistance deteriorate. When the content exceeds 12.0% by mass, adhesion to various substrates deteriorates.

[0058] Furthermore, among the polyfunctional monomers having a glass transition temperature of 10° C. or lower, those having a glass transition temperature of -20° C. or lower are preferred, and those having a glass transition temperature of -30° C. or lower are more preferred.

[0059] Furthermore, the α,β-unsaturated ether monomer may or may not be contained.

[0060] <F. Nitrogen-containing monofunctional monomer>

[0061] As the nitrogen-containing monofunctional monomer, for example, a compound selected from the following group can be used.

[0062] Acryloyl morpholine, vinyl methyl oxazolidinone, vinyl caprolactam and N,N-dimethyl acrylamide, acrylonitrile, (meth) acrylamide, diethyl acrylamide, N-vinyl carbazole, N-vinyl acetamide, N-vinyl pyrrolidone, N-hydroxymethyl (meth) acrylamide, diacetone acrylamide, N,N-dimethyl (meth) acrylamide, N,N-diethyl (meth) acrylamide, lactone modified flexible acrylate.

[0063] The active energy ray-curable inkjet ink composition contains 30.0% by mass or more of the nitrogen-containing monofunctional monomer in the total amount of all polymerizable components. Further, it is preferably 33.0% by mass or more, and more preferably 35.0% by mass or more. In addition, it contains 50.0% by mass or less, preferably 48.0% by mass or less, more preferably 45.0% by mass or less, and further preferably 40.0% by mass or less.

[0064] <Photopolymerization initiator>

[0065] The photopolymerization initiator that can be formulated in the active energy ray-curable inkjet ink composition of the present invention is not particularly limited.

[0066] As the photopolymerization initiator that can be used, for example, the following can be mentioned, but it is preferred not to use a photopolymerization initiator that causes coloring of the coating film such as yellowing over time. Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Irgacure 81), 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-diphenylthiophene ketone, Anthoxybenzoyl-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, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butane-1-one, and the like.

[0067] The content of the photopolymerization initiator in the active energy ray-curable inkjet ink composition of the present invention is not particularly limited, but is preferably 0.3 to 1.5% by mass, more preferably 0.4% by mass or more, and more preferably 0.8% by mass or less, based on the total amount of all polymerizable components.

[0068] <Sensitizer>

[0069] In the active energy ray-curable inkjet ink composition of the present invention, a sensitizer (compound) having light absorption characteristics mainly in the ultraviolet wavelength region of more than 400 nm and exhibiting a sensitization function of the curing reaction by light of the wavelength in this range can be used. In addition, if sufficient curing is possible, it is not necessary to use it. In addition, the so-called "exhibiting a sensitization function by light of a wavelength of more than 400 nm" means having light absorption characteristics in the wavelength region of more than 400 nm. By using such a sensitizer, the active energy ray-curable inkjet ink composition of the present invention can improve LED curability.

[0070] The above sensitizer is preferably an anthracene sensitizer or a thioxanthone sensitizer, etc. Among them, a thioxanthone sensitizer is preferred. These may be used alone or in combination of two or more.

[0071] Examples include anthracene sensitizers such as 9,10-dipropoxyanthracene and 9,10-bis(2-ethylhexyloxy)anthracene, and thioxanthone sensitizers such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. As representative examples of commercially available products, anthracene sensitizers include DBA and DEA (manufactured by Kawasaki Chemical Industries, Ltd.), and thioxanthone sensitizers include DETX and ITX (manufactured by Lambson Corporation).

[0072] The content of the sensitizer is preferably in the range of 0 to 8.0% by mass relative to the total amount of all polymerizable components. Even if it exceeds 8.0% by mass, no improvement in effect is observed, and excessive addition is undesirable.

[0073] In addition, when a thioxanthone sensitizer is used as a sensitizer, since there is a tendency for the active energy ray-curable inkjet printing ink composition to turn yellow, the hue will become more yellow than the color based on pigments (original hue), so it is preferred to appropriately determine the content of the thioxanthone sensitizer for each color.

[0074] Specifically, it is preferred that the white ink composition and the transparent ink composition, which are easily affected by the change in hue, do not contain a thioxanthone compound as a sensitizer. In addition, in the magenta ink composition and the cyan ink composition, there is a problem with the change in hue, so it is preferred to use it within the range where the hue does not cause a problem. In addition, the black ink composition and the yellow ink composition do not affect the hue even if there is a color change, and the photopolymerization is inferior to other hues, so it is preferred to use a thioxanthone compound as a sensitizer.

[0075] <Coloring agent>

[0076] The active energy ray-curable inkjet printing ink composition of the present invention may contain colorants of various hues, thereby obtaining active energy ray-curable inkjet printing ink compositions of various colors.

[0077] As such a colorant, pigments and dyes generally used in active energy ray-curable inkjet printing ink compositions can be used without limitation, but in view of light resistance, pigments such as organic pigments and inorganic pigments are preferred.

[0078] Examples of organic 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, xanthrone pigments, quinophthalone pigments, pyranthrone pigments, and indanthrone pigments. Examples of inorganic pigments include carbon black, titanium oxide, red iron oxide, black lead, iron black, chromium oxide green, and aluminum hydroxide pigments.

[0079] In addition, specific examples of pigments of representative hues of the active energy ray-curable inkjet printing ink composition of the present invention include the following.

[0080] First, examples of yellow pigments used in the yellow ink composition for active energy ray-curable inkjet printing 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, and 213, and CI Pigment Yellow 150, 155, 180, and 213 are preferably used.

[0081] Examples of the magenta pigment used for the magenta ink composition for active energy ray-curable inkjet printing include CI Pigment Red 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, 270, and CI Pigment Violet 19. Preferably, CI Pigment Red 122, 202, and CI Pigment Violet 19 are mentioned.

[0082] Examples of cyan pigments used in the active energy ray-curable cyan ink composition for inkjet printing include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 22, 27, 29, and 60, and CI Pigment Blue 15:4 is preferred.

[0083] Examples of the black pigment used for the active energy ray-curable black ink composition for inkjet printing include carbon black (CI Pigment Black 7) and the like.

[0084] Examples of the white pigment used for the active energy ray-curable white ink composition for inkjet printing include titanium oxide and aluminum oxide, and preferably titanium oxide surface-treated with various materials such as aluminum oxide and silicon dioxide is used.

[0085] The content of the pigment in the active energy ray-curable inkjet printing ink composition of the present invention is preferably 1 to 20% by mass relative to the total mass of the active energy ray-curable inkjet printing ink composition. If the content of the pigment is less than 1% by mass, the image quality of the resulting printed material tends to be reduced. On the other hand, if it exceeds 20% by mass, the viscosity characteristics of the active energy ray-curable inkjet printing ink composition tend to be adversely affected.

[0086] <Pigment dispersant>

[0087] Furthermore, the active energy ray-curable inkjet printing ink composition of the present invention may contain a pigment dispersant as necessary.

[0088] The pigment dispersant is a substance used to improve the dispersibility of the pigment and the storage stability of the ink composition of the present invention. The dispersants used in the past can be used without particular limitation, and polymer dispersants are preferably used. Examples of such pigment dispersants include carbodiimide dispersants, polyesteramine dispersants, fatty acid amine dispersants, modified polyacrylate dispersants, modified polyurethane dispersants, multi-chain polymer nonionic dispersants, polymer ion active agents, etc. These pigment dispersants are used alone or in combination of two or more.

[0089] When the total amount of pigment used is set to 100 parts by mass, it is preferred to contain 1 to 200 parts by mass of the above-mentioned pigment dispersant. If the content of the pigment dispersant is less than 1 part by mass, the pigment dispersibility and the storage stability of the ink composition of the present invention may sometimes decrease. On the other hand, more than 200 parts by mass of the pigment dispersant may be contained, but sometimes there is no difference in the effect. The more preferred lower limit of the content of the pigment dispersant is 5 parts by mass, and the more preferred upper limit is 60 parts by mass.

[0090] <Surfactant>

[0091] In order to improve discharge stability, the active energy ray-curable inkjet printing ink composition of the present invention preferably contains a surfactant such as a silicone-based surfactant conventionally used as a surfactant in active energy ray-curable inkjet printing ink compositions, depending on the inkjet head used.

[0092] Specific examples of the silicon-based surfactant include polyether-modified silicone oil, polyester-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, etc. These may be used alone or in combination of two or more.

[0093] The content of the surfactant in the ink composition of the present invention is preferably 0.005 to 1.0% by mass. If it is less than 0.005% by mass, the surface tension of the active energy ray-curable inkjet ink composition of the present invention becomes high, and the ejection stability from the inkjet head decreases. On the other hand, if it exceeds 1.0% by mass, bubbles increase in the active energy ray-curable inkjet ink composition, thereby decreasing the ejection stability.

[0094] <Additives>

[0095] In order to achieve various functionalities, various additives may be added to the active energy ray-curable inkjet ink composition of the present invention as needed. Specifically, surface conditioners, light stabilizers, surface treatment agents, antioxidants, anti-aging agents, crosslinking accelerators, polymerization inhibitors, plasticizers, preservatives, pH adjusters, defoamers, humectants, etc. may be mentioned. In addition, a non-curable resin that functions as a color carrier may be prepared or not prepared. In addition, a solvent may be contained or not contained.

[0096] (Surface Conditioner)

[0097] The active energy ray-curable inkjet ink composition preferably contains a surface conditioner. The surface conditioner is not particularly limited. For example, the surface conditioner is a silicone surface conditioner, a fluorine surface conditioner, an acetylene surface conditioner, etc. Acetylene surface conditioners are DYNOL 607, DYNOL 609, EXP-4001, EXP-4300, OLFINE E1010 (manufactured by Nissin Chemical Industry Co., Ltd.), etc. Silicone surfactants are BYK-307, 333, 347, 348, 349, 345, 377, 378, 3455 (manufactured by BYK Chemie), etc. Fluorine surfactants are F-410, 444, 553 (manufactured by DIC), FS-65, 34, 35, 31, 30 (manufactured by DuPont), etc.

[0098] When a surface conditioner is contained, the content of the surface conditioner is not particularly limited. For example, the content of the surface conditioner is preferably an amount that makes the surface tension of the ink composition within a range suitable for forming a coating film, and more preferably 0.1 to 1.5 mass % in the ink composition.

[0099] (Inhibitor)

[0100] The polymerization inhibitor is not particularly limited and can be, for example, N-CH3 type, NH type, N-OR type hindered amines, phenols, amines, sulfurs, phosphorus type, and the like.

[0101] (Defoaming Agent)

[0102] The defoaming agent is a silicone-based defoaming agent, a Pluronic (registered trademark)-based defoaming agent, or the like.

[0103] (Multifunctional monomers with a glass transition temperature exceeding 10°C)

[0104] The active energy ray-curable inkjet ink composition may contain a polyfunctional monomer having a glass transition temperature exceeding 10° C. within a range not impairing the effects of the present invention.

[0105] Examples of such a polyfunctional monomer are as follows: If the content is too large, the adhesion to the substrate will be deteriorated.

[0106] Ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, dipropylene glycol dimethacrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dihydroxymethyl-tricyclodecane di(meth)acrylate, hydroxy neopentyl glycol di(meth)acrylate, polytetramethylene glycol diacrylate, trimethylolpropane tri(meth)acrylate Acids and ethylene oxide modified products thereof, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and ethylene oxide modified products thereof, dipentaerythritol penta(meth)acrylate and ethylene oxide modified products thereof, dipentaerythritol hexa(meth)acrylate and ethylene oxide modified products thereof, polyurethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, pentaerythritol ethoxy tetraacrylate, caprolactam modified dipentaerythritol hexaacrylate, ethoxylated bisphenol A diacrylate, alkoxylated tetrahydrofurfuryl acrylate, etc.

[0107] <Physical Properties of the Active Energy Ray-Curable Inkjet Ink Composition of the Present Invention>

[0108] The viscosity of the active energy ray-curable inkjet printing ink composition of the present invention at 25° C. is preferably 10.0 cps or less. More specifically, the specific viscosity of the active energy ray-curable inkjet ink composition can be designed to suit the type of each inkjet device.

[0109] The viscosity in this specification is a viscosity measured at 25° C. and 20 rpm using an E-type viscometer (trade name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.).

[0110] Furthermore, the surface tension is preferably 20.0 to 25.0 mN / m.

[0111] (Manufacture of Active Energy Ray-Curable Inkjet Ink Composition)

[0112] Next, a method for producing the active energy ray-curable inkjet ink composition of the present invention using these materials will be described.

[0113] The active energy ray-curable inkjet ink composition of the present invention can be obtained by, for example, dispersing and mixing the components 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 ink composition as needed.

[0114] The active energy ray-curable inkjet printing ink composition of the present invention contains a specific amount of the above-mentioned specific photopolymerizable component, and thus has excellent curing properties to ultraviolet rays, especially ultraviolet rays using a light emitting diode (LED) as a light source, good adhesion and abrasion resistance to substrates such as acrylic resins, polystyrene, vinyl chloride, and polycarbonate, and excellent ejection stability and storage stability, and is excellent in all safety aspects such as high flash point, low skin irritation, and low odor.

[0115] The method for preparing the ink composition of the present invention is not particularly limited, and the ink composition can be prepared by adding all of the above-mentioned materials and mixing them using a bead mill, a triple roll mill, or the like.

[0116] In addition, a concentrated base ink can be obtained in advance by mixing a pigment, a pigment dispersant and a photopolymerizable component, and a photopolymerizable component and a photopolymerization initiator are added to the concentrated base ink in such a manner as to obtain the desired composition of the active energy ray-curable inkjet ink composition, and additives such as a surfactant are added as needed.

[0117] As the substrate for printing the ink composition of the present invention, acrylic resin, vinyl chloride, polystyrene, polycarbonate, etc. are preferred, but as long as it is a substrate (paper, plastic film, container, colloid, metal foil, glass, cloth, etc.) that has been printed with the active energy ray-curable inkjet ink composition in the past, printing can be carried out without any problem.

[0118] Specific examples of the method for printing and curing the ink composition of the present invention include a method in which the ink composition of the present invention is ejected onto a substrate using 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.

[0119] For example, the ink composition of the present invention can be ejected onto a substrate (printing of an image) by providing the 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 coating film thickness reaches, for example, 1 to 60 μm relative to the substrate. In addition, light exposure and curing (curing of an image) can be performed by irradiating light to the coating film of the ink composition of the present invention applied to the substrate as an image.

[0120] As the inkjet recording printing device for printing the ink composition of the present invention, a conventionally used inkjet recording printing device can be used. In addition, when a continuous inkjet recording printing device is used, a conductive agent is further added to the ink composition of the present invention to adjust the conductivity.

[0121] As the light source for curing the above-mentioned coating film, ultraviolet rays (UV lamp), ultraviolet rays (light emitting diode (LED)), electron beams, visible rays, etc. can be listed. From an environmental point of view, a light emitting diode (LED) that generates ultraviolet rays with a peak emission wavelength in the range of 350 to 420 nm is preferred.

[0122] 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”.

[0123] Example

[0124] 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".

[0125] 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 %".

[0126] (Viscosity of composition)

[0127] The active energy ray-curable inkjet ink compositions obtained in Examples and Comparative Examples were measured for viscosity (cps) at 25° C. and 20 rpm using an E-type viscometer (trade name: RE100L viscometer, manufactured by Toki Sangyo Co., Ltd.).

[0128] (Surface tension)

[0129] The surface tension of each active energy ray-curable inkjet ink composition was measured at a temperature of 25° C. using a dynamic wettability tester manufactured by RHESCA (trade name: WET-6000).

[0130] (Adhesion)

[0131] The active energy ray-curable inkjet ink composition was fully coated on each substrate of acrylic (acrylic resin), PVC (polyvinyl chloride resin), polycarbonate resin, and PS (polystyrene), and then irradiated with ultraviolet rays to cure.

[0132] The cured coating film thus formed on the substrate was cross-cut with a cutter to form a cured coating film of 100 square pieces. A transparent tape (manufactured by NICHIBAN, trade name: Cellotape (registered trademark)) was pasted to the cut part, and it was peeled off, and the number of square pieces that were not adhered to the transparent tape and peeled off and remained on the substrate was counted. For example, 100 / 100 means that 1 piece was not peeled off and all pieces remained on the substrate, and 20 / 100 means that 20 pieces remained on the substrate and 80 pieces adhered to the transparent tape and were peeled off.

[0133] (Pencil hardness)

[0134] Each cured coating film was evaluated by a pencil scratch test (pencil hardness) in accordance with Japanese Industrial Standard JIS K5600-5-4.

[0135] (Abrasion resistance)

[0136] The cured coating film was rubbed 200 times with a bleached cloth using a Gakushin fastness tester (manufactured by Daiei Kagaku Seiki Mfg. Co., Ltd.) with a weight of 500 g. The peeling of the cured film from the K paperboard and C paperboard coated with the pre-coating agent was visually observed and evaluated according to the following evaluation criteria.

[0137] ○: There is no peeling of the cured film.

[0138] △: The surface of the cured film has scratches.

[0139] ×: The cured film peeled off and the sheet was visible.

[0140] (Water resistance)

[0141] The cured coating film was rubbed 20 times with a wet cotton swab, and the state of the printed matter after rubbing was observed. The water resistance was evaluated according to the following evaluation criteria.

[0142] ○: Printing is not blurred.

[0143] △: The printing is slightly blurred, but the text can be clearly understood.

[0144] ×: The printing is blurred and the text cannot be deciphered.

[0145] (LED curing)

[0146] The inkjet recording device and the active energy ray-curable inkjet ink composition were placed at an ambient temperature of 25° C. for 24 hours to allow the temperature of the inkjet recording device and the ink composition to reach 25° C. Then, the active energy ray-curable inkjet ink composition was continuously printed (printed) on a PVC sheet 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 coating surface at a UV cumulative light dose of 180 mJ / cm 2 The obtained curable coating film was rubbed with a cotton swab and the curability was evaluated from the degree of peeling.

[0147] ○: No peeling.

[0148] △: There is some peeling.

[0149] ×: There is peeling.

[0150] (Materials used)

[0151] <Coloring agent>

[0152] Red Pigment (PR122)

[0153] Yellow Pigment(PY150)

[0154] Blue pigment (PB15:4)

[0155] Black Pigment (PB7)

[0156] White Pigment(PW6)

[0157] <Pigment dispersant>

[0158] Pigment dispersant a (EFKAPX4701: manufactured by BASF)

[0159] Pigment dispersant b (SOLSPERSE 56000: manufactured by Japan LUBRIZOL Co., Ltd.)

[0160] Pigment dispersant c (BYKJET9151: manufactured by BYK Chemie)

[0161] Pigment dispersant d (PB821: manufactured by Ajinomoto Fine Technologies Co., Ltd.)

[0162] <A. Polyfunctional amine-modified oligomer>

[0163] Polyfunctional amine-modified oligomer a (CN371NS: manufactured by Sartomer)

[0164] Polyfunctional amine-modified oligomer b (CN373: manufactured by Sartomer)

[0165] Polyfunctional amine-modified oligomer c (AgiSyn008: manufactured by DSM-Agi)

[0166] Polyfunctional amine-modified oligomer d (AgiSyn003: manufactured by DSM-Agi)

[0167] <C. Monofunctional monomer having a glass transition temperature of 20°C or higher>

[0168] Isobornyl acrylate (trade name: SR506, manufactured by Sartomer) Tg = 88°C

[0169] Cyclotrimethylolpropane formal acrylate (CTFA) (trade name: SR531, manufactured by Sartomer) Tg = 32°C

[0170] <D. Monofunctional monomer having a glass transition temperature of 10°C or less>

[0171] Ethyl carbitol acrylate (trade name: V190, manufactured by Osaka Organic Chemical Industry Co., Ltd.) Tg = -67°C Tetrahydrofurfuryl acrylate (trade name: SR285, manufactured by Sartomer Co., Ltd.) Tg = -15°C

[0172] Benzyl acrylate (trade name: V160, manufactured by Osaka Organic Chemical Industry Co., Ltd.) Tg = 6°C

[0173] <E. Polyfunctional monomer having a glass transition temperature of 10°C or less>

[0174] Ethylene oxide 3 mol addition trimethylolpropane triacrylate ((EO)TMPTA) (trade name: SR454, manufactured by Sartomer) Tg = -40°C

[0175] <Other multifunctional monomers>

[0176] Trimethylolpropane triacrylate (trade name: SR351, manufactured by Sartomer) Tg = 62°C Dipropylene glycol diacrylate (trade name: SR508, manufactured by Sartomer) Tg = 104°C

[0177] <F. Nitrogen-containing monofunctional monomer>

[0178] Acryloylmorpholine: (ACMO: manufactured by KJ CHEMICALS) Tg = 145°C

[0179] N-vinyl caprolactam: (V-CAP: manufactured by ISP JAPAN Co., Ltd.) Tg = 90°C

[0180] <Photopolymerization initiator>

[0181] TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by Lambson)

[0182] <Sensitizer>

[0183] DETX: 2,4-diethylthioxanthone (produced by Lambson)

[0184] <Polymerization inhibitor>

[0185] MEHQ (monomethyl hydroquinone ether)

[0186] UV-22: Quinone type polymerization inhibitor (manufactured by Kromachem)

[0187] <Leveling agent>

[0188] BYK-377 (solid content 100%, polyether-modified silicone surfactant, manufactured by BYK Chemie Japan Co., Ltd.)

[0189] (Examples and Comparative Examples)

[0190] <Production of Active Energy Ray-Curable Inkjet Ink Compositions of Examples and Comparative Examples>

[0191] The components were mixed so as to have the composition shown in the following table to prepare an active energy ray-curable inkjet ink composition.

[0192] [Table 1-1]

[0193]

[0194] [Table 1-2]

[0195]

[0196] [Table 1-3]

[0197]

[0198] The active energy ray-curable inkjet ink composition of the present invention has a low viscosity before curing and has an appropriate surface tension.

[0199] Furthermore, it can be cured by LED, and its cured coating has good adhesion to various substrates and has high pencil hardness, abrasion resistance and water resistance.

[0200] However, according to Comparative Example 1 which did not contain (A) a polyfunctional amine-modified oligomer, LED curing was poor, and according to Comparative Example 2 which contained a large amount of (A) a polyfunctional amine-modified oligomer, the ink composition had a high viscosity and a possibility of poor ejection properties. According to Comparative Example 3 which did not contain (E) a polyfunctional monomer having a glass transition temperature of 10°C or less, the pencil hardness of the coating film was low, and the friction resistance and water resistance were poor. According to Comparative Example 4 which contained an excessive amount of (E) a polyfunctional monomer having a glass transition temperature of 10°C or less, the adhesion to each substrate was poor and the cured coating film was too hard.

[0201] In addition, according to Comparative Example 5 in which the content of the nitrogen-containing monofunctional monomer (F) was small, LED curing properties were poor, whereas according to Comparative Example 6 in which the content was large, the ink composition had a high viscosity and was likely to have poor ejection properties. According to Comparative Examples 7 and 8 in which a polyfunctional monomer having a glass transition temperature of more than 10° C. was used instead of a polyfunctional monomer having a glass transition temperature of 10° C. (E), the coating film had poor adhesion to each substrate.

Claims

1. An active energy ray-curable inkjet ink composition, characterized in that: Satisfy all of the following conditions (A) to (F): (A) The total amount of all polymerizable components contains 0.2 to 14.0 mass % of a polyfunctional amine-modified oligomer; the polyfunctional amine-modified oligomer used is CN501, CN550, CN373, CN383 and CN371NS manufactured by Sartomer, EBECRYL 80, EBECRYL 81, EBECRYL 83 and EBECRYL 7100 manufactured by Daicel-allnex, LAROMER PO83F and LAROMER PO 84F manufactured by BASF, and AgiSyn001, AgiSyn002, AgiSyn003, AgiSyn005, AgiSyn006, AgiSyn007 and AgiSyn008 manufactured by DSM-Agi; (B) containing 50.0 mass % or more of a monofunctional monomer in the total amount of all polymerizable components; (C) the total amount of the total polymerizable components contains 30.0 mass % or more of a monofunctional monomer having a glass transition temperature of 20°C or more; the monofunctional monomer having a glass transition temperature of 20°C or more includes: acryloyl morpholine, vinyl caprolactam, acrylamide, diethyl acrylamide, isobornyl (meth)acrylate or cyclotrimethylolpropane formal acrylate; (D) The total amount of the total polymerizable components contains 20.0 mass % or more of a monofunctional monomer having a glass transition temperature of 10°C or less; the monofunctional monomer having a glass transition temperature of 10°C or less includes: ethyl carbitol acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate; (E) The total amount of the total polymerizable components contains 3.0 to 12.0 mass % of a multifunctional monomer having a plurality of carbon-carbon unsaturated bonds in the molecule and having a glass transition temperature of 10° C. or less, wherein the multifunctional monomer having a plurality of carbon-carbon unsaturated bonds in the molecule includes: vinyloxyethoxyethyl (meth)acrylate, ethoxylated (3) trimethylolpropane triacrylate, propoxylated (3) trimethylolpropane triacrylate, EO-modified bisphenol A diacrylate, polyethylene glycol di(meth)acrylate having an average molecular weight of 400, polyethylene glycol diacrylate having an average molecular weight of 600, and alkoxylated hexanediol diacrylate; wherein the EO-modified bisphenol A diacrylate is a bisphenol A diacrylate to which 10 or 20 moles of ethylene oxide are added per mole of bisphenol A diacrylate during the modification process; (F) the total amount of all polymerizable components contains 30.0 to 50.0 mass % of a nitrogen-containing monofunctional monomer, wherein the nitrogen-containing monofunctional monomer is at least one selected from the group consisting of acryloylmorpholine, vinylmethyloxazolidinone, vinylcaprolactam and N,N-dimethylacrylamide, However, the following are excluded: A photocurable inkjet printing ink composition that satisfies the following conditions A to E: A. containing 5 to 50% by mass of 3,3,5-trimethylcyclohexyl acrylate in the total photopolymerizable compound; B. containing 1 to 15% by mass of a multifunctional monomer and / or a multifunctional oligomer having a glass transition temperature of 10° C. or less in the total photopolymerizable compound; C. containing 40% by mass or more of monofunctional monomers in total in the total photopolymerizable compound; D. Containing monomers and / or oligomers having amino groups and / or amide groups; E. The viscosity of the ink composition is 10 mPa at 25°C s or less.

2. The active energy ray-curable inkjet ink composition according to claim 1, wherein The nitrogen-containing monofunctional monomers include acryloylmorpholine and vinylcaprolactam.

3. The active energy ray-curable inkjet ink composition according to claim 2, wherein: The active energy ray-curable inkjet ink composition contains a "mass ratio of acryloylmorpholine to vinylcaprolactam" of 1.00 to 2.20.

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