Active energy ray curable ink composition for ink jet printing

Abstract

The present invention addresses the problem of obtaining an active-energy-ray-curable jet printing ink composition in which a plant-derived raw material is used, and furthermore of providing an active-energy-ray-curable inkjet printing ink composition in which the ink composition has low odor, low viscosity, excellent curability by active energy rays, no occurrence of curing wrinkles in a cured coating film, and excellent curing properties and bending resistance. As a solution to this problem, the present invention provides an active-energy-ray-curable inkjet ink composition that satisfies conditions A through E and in which the total quantity of (D) and (E) is 30.0-60.0 mass% in the active-energy-ray-curable inkjet printing ink composition. (A): The content of an acrylated amine compound having two photopolymerizable functional groups and two amino groups in each molecule thereof in the active-energy-ray-curable inkjet printing ink composition is 1.0-20.0 mass%. (B): The content of a (meth)acrylate monomer having an alkoxy group in the active-energy-ray-curable inkjet printing ink composition is 2.0-20.0 mass%. (C): The content of a (meth)acrylate monomer having a C10-20 alkyl group in the active-energy-ray-curable inkjet printing ink composition is 2.0-25.0 mass%. (D): The content of at least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, and hydroxy pivalic acid neopentyl glycol diacrylate in the active-energy-ray-curable inkjet printing ink composition is 5.0-25.0 mass%. (E): The content of plant-derived 1,10-decanediol diacrylate in the active-energy-ray-curable inkjet printing ink composition is 10.0-40.0 mass%.

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable ink jet printing ink composition suitable for printing on substrates such as papers and sheets made of resins such as vinyl chloride polymers and ethylene-vinyl acetate copolymers, particularly cardboard sheets, and to a printed matter obtained using the same. [Background technology]

[0002] As described in Patent Document 1, it is known that an issue to be addressed is how to prevent the occurrence of curing wrinkles when an active energy ray-curable inkjet ink is cured. In addition, an inkjet ink composition containing an amine-modified oligomer and a monomer having multiple (meth)acryloyl groups is also known, for example, as described in Patent Document 2. However, such an ink composition does not satisfy the requirements C and D of the present invention. In recent years, biomass has been attracting attention as a non-exhaustible industrial resource. Biomass is a renewable organic resource derived from living organisms, excluding fossil resources. For the purpose of environmental conservation, biomass polymers, which use biomass as a raw material, have been developed since the 1980s. Biomass polymers are considered useful as a measure to prevent global warming, and are expected to be used as materials for a wide variety of products, including molding, fibers, nonwoven fabrics, packaging, toner, ink, paint, films, sheets, foams, coatings, and adhesives. In the field of actinic ray-curable inkjet inks used on cardboard, there is a demand for actinic ray-curable inkjet inks that use "biomass" and actinic ray-curable inkjet inks that have little odor and excellent resistance to bending and abrasion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2007 / 074768 [Patent Document 2] International Publication No. 2017 / 073654 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to obtain an active energy ray-curable ink composition for inkjet printing that uses raw materials derived from plants, and further to provide an active energy ray-curable ink composition for inkjet printing that has little odor, low viscosity, excellent curability by active energy rays, does not cause cured wrinkles in the cured film, and has excellent curability and bending resistance. [Means for solving the problem]

[0005] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by using a specific composition, and have thus completed the present invention. That is, the present invention is as follows. 1. An active energy ray-curable ink composition for inkjet printing, which satisfies the following requirements (A) to (E), and the total content of the compounds (D) and (E) in the active energy ray-curable ink composition for inkjet printing is 30.0 to 60.0 mass %. (A) An acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is contained in an amount of 1.0 to 20.0% by mass in an active energy ray-curable ink composition for inkjet printing. (B) An active energy ray-curable ink composition for inkjet printing contains a (meth)acrylate monomer having an alkoxy group at 2.0 to 20.0% by mass. (C) The active energy ray-curable ink composition for inkjet printing contains 2.0 to 25.0% by mass of a (meth)acrylate monomer having an alkyl group having 10 to 20 carbon atoms. (D) At least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, and hydroxypivalic acid neopentyl glycol diacrylate is contained in an active energy ray-curable ink composition for inkjet printing at a content of 5.0 to 25.0% by mass. (E) An active energy ray-curable ink composition for inkjet printing contains 10.0 to 40.0% by mass of 1,10-decanediol diacrylate derived from vegetable oil. 2. The actinic ray-curable ink composition for ink-jet printing according to 1, wherein 50 to 100 mass % of the (meth)acrylate monomer having an alkoxy group of (B) is a polyfunctional alkoxy(meth)acrylate monomer. 3. The actinic ray-curable ink composition for ink-jet printing according to 1 or 2, further comprising (F) a photopolymerization initiator. 4. (F) A photopolymerization initiator, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, Ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide, Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, Oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone}, Polymer type initiators, Bis[4-(2-hydroxy-2-methylpropanoyl)phenyl]ether, 4. The actinic ray-curable ink composition for ink-jet printing according to any one of 1 to 3, wherein the active energy ray-curable ink composition for ink-jet printing according to any one of 1 to 3 is one or more selected from the following: 5. The active energy ray-curable ink composition for inkjet printing according to any one of items 1 to 4, wherein (G) a (meth)acrylate monomer having a hydroxyl group is contained in the active energy ray-curable ink composition for inkjet printing in an amount of 3.0 to 20.0 mass %. 6. The actinic ray-curable ink composition for ink-jet printing according to any one of items 1 to 5, wherein (C) the (meth)acrylate monomer having an alkyl group having 10 to 20 carbon atoms is lauryl acrylate derived from vegetable oil. 7. The actinic ray-curable ink composition for ink-jet printing according to any one of items 1 to 6, further comprising (H) a colorant. Effect of the Invention

[0006] The actinic energy ray-curable ink composition for inkjet printing of the present invention can print satisfactorily even if it contains raw materials derived from plants. It has little odor, low viscosity, excellent curability when cured by actinic energy rays, does not cause cured wrinkles in the cured film, and exhibits excellent curability and bending resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The actinic energy ray-curable ink composition for ink-jet printing of the present invention satisfies the above requirements A to E, and will be described below in order. <Requirement A> Requirement A is that the actinic energy ray-curable ink composition for inkjet printing contains an acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule in an amount of 1.0 to 20.0 mass %. Here, the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is not limited. For example, the photopolymerizable functional group in the acrylated amine compound may be a functional group that undergoes polymerization reaction by visible light or invisible light including ionizing radiation such as ultraviolet light or electron beam, and can form a crosslinked bond between molecules. In addition, the photopolymerizable functional group includes both a narrow-sense photopolymerizable functional group that is directly activated by light irradiation and undergoes photopolymerization reaction, and a broad-sense photopolymerizable functional group that initiates and promotes polymerization reaction by the action of active species generated from a photopolymerization initiator when the photopolymerizable functional group and a photopolymerization initiator are coexisting and irradiated with light.

[0008] The photopolymerizable functional group may be one having photoradical polymerization reactivity such as an ethylenic double bond, one having photocationic polymerization or photoanionic polymerization reactivity such as a cyclic ether group such as an epoxy group, etc. Among these, the photopolymerizable functional group is preferably an ethylenic double bond such as a (meth)acryloyl group, a vinyl group, an allyl group, etc., and more preferably a (meth)acryloyl group. It is preferable that the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule has both (meth)acryloyl groups and an amine value of 130 to 142 KOHmg / g. The amine value means the amine value per 1 g of solid content, and is a value converted into the equivalent amount of potassium hydroxide after measuring by potentiometric titration (e.g. COMTITE (AUTO TITRATOR COM-900, BURET B-900, TITSTATION K-900), manufactured by Hiranuma Sangyo Co., Ltd.) using a 0.1 N aqueous hydrochloric acid solution.

[0009] The acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is preferably an acrylated amine compound obtained by reacting a bifunctional (meth)acrylate with an amine compound. Bifunctional (meth)acrylates include alkylene glycol di(meth)acrylates such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate, di(meth)acrylates of ethylene oxide adducts of bisphenol A, di(meth)acrylates of ethylene oxide adducts of bisphenol F, and bisphenol A di(meth)acrylates of ethylene oxide adducts of bisphenol B. Examples of the difunctional (meth)acrylate include bisphenol alkylene oxide adduct di(meth)acrylates such as di(meth)acrylate of ethylene oxide adduct of phenol S, di(meth)acrylate of ethylene oxide adduct of thiobisphenol, and di(meth)acrylate of ethylene oxide adduct of brominated bisphenol A, polyalkylene glycol di(meth)acrylates such as polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate, and di(meth)acrylate of hydroxypivalic acid neopentyl glycol ester. Among these, the bifunctional (meth)acrylate is preferably 1,6-hexanediol di(meth)acrylate.

[0010] Examples of the amine compound include monofunctional amine compounds such as benzylamine, phenethylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, n-pentylamine, isopentylamine, n-hexylamine, cyclohexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, and n-octadecylamine; diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,6-hexamethylenetetramine, and the like. Examples of suitable amine compounds include polyfunctional amine compounds such as phenylenediamine, 1,8-octamethylenediamine, 1,12-dodecamethylenediamine, o-phenylenediamine, p-phenylenediamine, m-phenylenediamine, o-xylylenediamine, p-xylylenediamine, m-xylylenediamine, menthanediamine, bis(4-amino-3-methylcyclohexylmethane), isophoronediamine, 1,3-diaminocyclohexane, and spiroacetal diamines. The amine compound may also be a high molecular weight type polyfunctional amine compound such as polyethyleneimine, polyvinylamine, or polyallylamine.

[0011] The acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is preferably a compound obtained by reacting 1,6-hexanediol di(meth)acrylate with an amine compound. Specifically, it is an acrylated amine compound such as CN371, CN373, CN383, CN386 (manufactured by Sartomer), which is an oligomer of an acrylated amine compound having two active energy ray polymerizable functional groups and two amino groups in the molecule. In addition, EB7100 (EBECRYL 7100, manufactured by Cytec), Agi008 (manufactured by DSM), etc. can also be used. The content of the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule in the actinic energy ray-curable ink composition for inkjet printing is 1.0 mass % or more, preferably 4.0 mass % or more, and more preferably 5.0 mass % or more. Furthermore, the content of the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule in the active energy ray-curable ink composition for inkjet printing is 20.0 mass % or less, preferably 12.0 mass % or less, and more preferably 9.0 mass % or less. When the content of the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is less than 1.0% by mass, the curability of the active energy ray-curable ink composition for inkjet printing tends to be poor. On the other hand, when the content exceeds 20.0% by mass, the storage stability and ejection stability of the ink composition tend to be reduced.

[0012] Furthermore, the content of the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule relative to all photopolymerizable components in the active energy ray-curable ink composition for inkjet printing is preferably 1.2 mass % or more, and more preferably 4.0 mass % or more. Furthermore, the content of the acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule relative to all photopolymerizable components in the active energy ray-curable ink composition for inkjet printing is preferably 17.0 mass % or less, and more preferably 14.0 mass % or less.

[0013] <Requirement B> Requirement B is that the active energy ray-curable ink composition for ink-jet printing contains an alkoxy group-containing (meth)acrylate monomer in an amount of 2.0 to 20.0 mass % of the total polymerizable components. The (meth)acrylate monomer having an alkoxy group is not particularly limited. For example, the (meth)acrylate monomer may be any monofunctional (meth)acrylate monomer, bifunctional (meth)acrylate monomer, trifunctional (meth)acrylate monomer, or polyfunctional acrylate monomer having 4 or more functional groups, each of which has little odor. In consideration of the environmental aspect, a (meth)acrylate monomer having an alkoxy group derived from biomass may be used. Specific examples of the alkoxyalkyl (meth)acrylate include monofunctional alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 3-methoxybutyl (meth)acrylate, and 2-butoxyethyl (meth)acrylate; and polyalkylene glycol structure-containing monofunctional alkoxy group-containing (meth)acrylates such as 2-butoxydiethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxytripropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol-polypropylene glycol-mono(meth)acrylate, lauroxypolyethylene glycol mono(meth)acrylate, and stearoxypolyethylene glycol mono(meth)acrylate. Furthermore, polyfunctional alkoxy group-containing (meth)acrylates such as ethoxylated (3) trimethylolpropane tri(meth)acrylate and propoxylated (2) neopentyl glycol di(meth)acrylate can also be used.

[0014] The content of the alkoxy group-containing (meth)acrylate monomer in the actinic energy ray-curable ink composition for ink-jet printing is preferably 2.0 mass % or more. Furthermore, the content of the alkoxy group-containing (meth)acrylate monomer in the actinic energy ray-curable ink composition for inkjet printing is 20.0 mass % or less, and preferably 13.0 mass % or less. If the content of the alkoxy group-containing (meth)acrylate monomer in the actinic energy ray-curable ink composition for inkjet printing is less than 2.0% by mass, the bending resistance will be poor, and if it exceeds 20.0% by mass, the water resistance may be poor. Also, it is preferable that 50 to 100 mass % of the alkoxy group-containing polyfunctional (meth)acrylate in requirement B is an alkoxy group-containing polyfunctional (meth)acrylate. When the alkoxy group-containing polyfunctional (meth)acrylate is in this range, a coating film having excellent abrasion resistance can be obtained.

[0015] <Requirement C> Requirement C is that the active energy ray-curable ink composition for inkjet printing contains 2.0 to 25.0 mass % of an alkyl group-containing (meth)acrylate having 10 to 20 carbon atoms. The alkyl group having 10 to 20 carbon atoms may have any of a linear, branched, and alicyclic structure. Here, the (meth)acrylate containing an alkyl group having 10 to 20 carbon atoms is a monofunctional (meth)acrylate. Examples thereof include tridecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, isodecyl (meth)acrylate, isotetradecyl (meth)acrylate, isobornyl (meth)acrylate, and cyclohexyl (meth)acrylate.

[0016] The content of the (meth)acrylate containing an alkyl group having 10 to 20 carbon atoms in the actinic energy ray-curable ink composition for inkjet printing is 2.0 mass % or more, preferably 3.0 mass % or more, and more preferably 5.0 mass % or more. Furthermore, the content of the (meth)acrylate containing an alkyl group having 10 to 20 carbon atoms in the actinic energy ray-curable ink composition for inkjet printing is 25.0 mass % or less, preferably 23.0 mass % or less, and more preferably 21.0 mass % or less. If the content of the (meth)acrylate containing an alkyl group having 10 to 20 carbon atoms in the actinic energy ray-curable ink composition for inkjet printing is less than 2.0 mass %, the bending resistance will be poor, and if it exceeds 25.0 mass %, the abrasion resistance will be poor.

[0017] One of the raw materials of this alkyl group-containing (meth)acrylate having 10 to 20 carbon atoms is (meth)acrylic acid, and the other raw material is an alcohol having 10 to 20 carbon atoms. This alcohol can be obtained, for example, from a raw material derived from a plant, and has renewable carbon. The raw material derived from a plant is a plant raw material such as palm oil, palm kernel oil, coconut oil, etc. Since alkyl groups having 10 to 20 carbon atoms have a relatively large number of carbon atoms, the more (meth)acrylate made from such an alkyl group in the actinic energy ray-curable ink composition for inkjet printing is used, the more biomass-derived carbon can be used in the entire composition.

[0018] <Requirement D> Requirement D is that the active energy ray-curable ink composition for inkjet printing contains 5.0 to 25.0 mass % of at least one selected from 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, and hydroxypivalic acid neopentyl glycol diacrylate. The total content of these di(meth)acrylates in the actinic energy ray-curable ink composition for inkjet printing is 5.0 mass % or more, preferably 7.0 mass % or more, and more preferably 9.0 mass % or more. The total content of these diacrylates in the active energy ray-curable ink composition for inkjet printing is 25.0 mass % or less, preferably 23.0 mass % or less, and more preferably 21.0 mass % or less.

[0019] <Requirement E> Requirement E is that the active energy ray-curable ink composition for inkjet printing contains 10.0 to 40.0% by mass of 1,10-decanediol diacrylate derived from vegetable oil. "Derived from vegetable oil" indicates that one of the raw materials, 1,10-decanediol, is derived from vegetable oil. The total content of 1,10-decanediol diacrylate in the actinic energy ray-curable ink composition for inkjet printing is 10.0 mass % or more, preferably 13.0 mass % or more, and more preferably 17.0 mass % or more. The total content of these di(meth)acrylates in the active energy ray-curable ink composition for inkjet printing is 40.0 mass % or less, preferably 35.0 mass % or less, and more preferably 33.0 mass % or less. The total amount of the compounds satisfying requirements D and E is contained in the active energy ray-curable ink composition for inkjet printing in a range of 30.0 to 60.0% by mass. If the total amount of requirements D and E is less than 30.0% by mass, the abrasion resistance is poor, and if it exceeds 60.0% by mass, the bending resistance is poor.

[0020] <Requirement G> As for requirement G, the (meth)acrylate monomer having a hydroxyl group can be contained in the active energy ray-curable ink composition for inkjet printing in an amount of 3.0 to 20.0 mass %. However, the active energy ray-curable ink composition for inkjet printing may or may not contain the (meth)acrylate monomer having a hydroxyl group. As the (meth)acrylate monomer having a hydroxyl group, one or more of the following monomers can be used. Hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; polyethylene glycol mono(meth)acrylates such as diethylene glycol monoethyl ether (meth)acrylate; glycol mono(meth)acrylates such as polypropylene glycol mono(meth)acrylate and 1,4-cyclohexanedimethanol mono(meth)acrylate; caprolactone-modified (meth)acrylates; hydroxyethylacrylamide; and EO (ethylene oxide)-modified succinic acid (meth)acrylate. In addition, (meth)acrylate monomers having a hydroxyl group such as 4-hydroxybutyl (meth)acrylate, which has little odor, are preferred.

[0021] In the present invention, the content of the (meth)acrylate monomer having a hydroxyl group in all photopolymerizable components in the active energy ray-curable ink composition for inkjet printing is preferably 7.0% by mass or more and preferably 15.0% by mass or less.

[0022] <Requirement I> As requirement I, a vinyl monomer can be contained. The vinyl monomer can be contained in an amount of 1.0 to 20.0 mass % of the total polymerizable components in the active energy ray curable ink composition for ink jet printing. By containing a vinyl monomer, when the ink composition is printed on a cardboard sheet or the like and the cardboard sheet or the like is folded, the folding resistance becomes better. However, the actinic energy ray-curable ink composition for ink-jet printing may or may not contain a vinyl monomer. The vinyl monomer is not particularly limited. Examples of the vinyl monomer include ethylene glycol divinyl ether, triethylene glycol divinyl ether, diethylene glycol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, ethylene glycol monovinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, and trimethylolpropane trivinyl ether. Among these, the vinyl monomer is preferably triethylene glycol divinyl ether or the like, which has little odor.

[0023] <Other compounds> In the present invention, in addition to the polymerizable components covered by requirements A to E, G, and I, polymerizable compounds can be contained within a range in which performance is not deteriorated and there is little odor. In the description of the compounds below, the (poly) before the polyol portion means a condensation product of mono-, di- or higher polyols. (Alkylene glycol di(meth)acrylate) (Poly)alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; 1,4-butanediol di(meth)acrylate, 1,5-propanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate; ,2-Hexanediol di(meth)acrylate, 1,5-Hexanediol di(meth)acrylate, 2,5-Hexanediol di(meth)acrylate, 1,7-Heptanediol di(meth)acrylate, 1,8-Octanediol di(meth)acrylate, 1,2-Octanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, 1,2-Decanediol di(meth)acrylate, 2-Methyl-2-Propyl-1,3-Propanediol di(meth)acrylate, 2,4-Dimethyl- 2,4-Pentanediol di(meth)acrylate, 2,2-Diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-Trimethyl-1,3-pentanediol di(meth)acrylate, 1,12-Dodecanediol di(meth)acrylate, 1,2-Dodecanediol di(meth)acrylate, 1,14-Tetradecanediol di(meth)acrylate, 1,2-Tetradecanediol di(meth)acrylate, 1,16-Hexadecanediol di(meth)acrylate, 1,2-Hexadecanediol butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-Pentanediol di(meth)acrylate, Polyethylene glycol di(meth)acrylate, Polypropylene glycol di(meth)acrylate,

[0024] ((Poly)glycerin poly(meth)acrylate) Glycerin di(meth)acrylate, glycerin tetra(meth)acrylate, diglycerin tetra(meth)acrylate, ((Poly)trimethylolpropane poly(meth)acrylate) Trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tetra(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate,

[0025] ((Poly)pentaerythritol poly(meth)acrylate) Pentaerythritol tetra(meth)acrylate and its ethylene oxide modified products, dipentaerythritol penta(meth)acrylate and its ethylene oxide modified products, dipentaerythritol hexa(meth)acrylate and its ethylene oxide modified products, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate.

[0026] (Other polyacrylates) As polyhydric acrylates not included in the above, the following can be used. Monomers having 4 or more functional groups, such as pentaerythritol tetracaprolactonate tetra(meth)acrylate, ditrimethylolpropane tetracaprolactonate tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexane tetra(meth)acrylate, ditrimethyloloctane tetra(meth)acrylate, and tripentaerythritol polyalkylene oxide hepta(meth)acrylate, Hydroxypivalyl hydroxypivalate di(meth)acrylate, hydroxypivalyl hydroxypivalate dicaprolactonate di(meth)acrylate, and the like. Incidentally, 2-(2-vinyloxyethoxy)ethyl acrylate and methyl 2-(allyloxymethyl)acrylate may or may not be contained.

[0027] <Other photopolymerizable components> Examples of photopolymerizable components that can be incorporated in the actinic ray-curable ink composition for ink-jet printing of the present invention include the following. Benzyl (meth)acrylate, butyl (meth)acrylate, ethyl carbitol (meth)acrylate, caprolactone (meth)acrylate, methoxytripropylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate, Other examples include acryloylmorpholine, acrylonitrile, acrylamide, diethylacrylamide, styrene, (meth)acrylic acid, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, pentaerythritol ethoxy tetraacrylate, caprolactam-modified dipentaerythritol hexaacrylate, ethoxylated bisphenol A diacrylate, alkoxylated tetrahydrofurfuryl acrylate, dimethylol-tricyclodecane di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, polytetramethylene glycol diacrylate, trimethylolpropane tri(meth)acrylate, and its ethylene oxide modified product, pentaerythritol tri(meth)acrylate, and the like. The amide group-containing monomer may or may not be contained.

[0028] <Requirement F> The actinic energy ray-curable ink composition for ink-jet printing of the present invention may contain a photopolymerization initiator. When an electron beam is used as the actinic energy ray, the ink composition may or may not contain a photopolymerization initiator. Examples of photopolymerization initiators that can be used include the following. Acylphosphine oxide polymerization initiators include bis-2,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzyl-diphenylphosphine oxide (TPO), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Irgacure 819 or SB-PI719), and ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide (TPOL). α-Hydroxyketone polymerization initiators include 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (Irgacure 127), 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone (Irgacure 2959), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184), oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} (ESACURE ONE), 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis[4-(2-hydroxy-2-methylpropanoyl)phenyl]ether (KIP160), and the like.

[0029] Other examples include benzophenone compounds (4,4'-diethylaminobenzophenone, etc.), 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropan-1-one, 4'-(methylthio)-α-morpholino-α-methylpropiophenone, thiophenyl compounds (4-benzoyl-4'-methyldiphenyl sulfide), thioxanthone compounds (2,4-diethylthioxanthone, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone), 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butan-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, ethyl Michler's ketone, and polymer-type initiators (Omnipol TP, Omnipol BP), 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one (ESACURE1001M). Such photopolymerization initiators are commercially available and can be obtained under the trade names, for example, Irgacure 907, Irgacure 369, Irgacure 184, Irgacure 379, Irgacure 819, TPO, etc. A plurality of photopolymerization initiators may be used in combination.

[0030] Among these, it is preferable to use an acylphosphine oxide polymerization initiator in combination with an α-hydroxyketone polymerization initiator, and it is further preferable to use 2,4,6-trimethylbenzyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} in combination. The thioxanthone-based photopolymerization initiator may not be contained.

[0031] The content of the photopolymerization initiator is not particularly limited. For example, when ultraviolet light (UV) or ultraviolet light (light-emitting diode (LED)) is used as the light source, the content of the photopolymerization initiator in the active energy ray curable ink composition for inkjet printing is preferably 3.0% by mass or more, more preferably 4.0% by mass or more. The content of the photopolymerization initiator in the active energy ray curable ink composition for inkjet printing is preferably 25.0% by mass or less, more preferably 15.0% by mass or less. By having the content of the photopolymerization initiator within the above range, the active energy ray curable ink composition for inkjet printing can have sufficient curability, internal curability, and low cost.

[0032] (sensitizer) In the active energy ray-curable ink composition for inkjet printing of the present invention, a photosensitizer (compound) that has light absorption properties mainly in the ultraviolet wavelength range of 400 nm or more and exhibits a sensitizing function for the curing reaction by light in that range of wavelengths can be used together with the polymerization initiator in order to promote curing properties against ultraviolet light using a light-emitting diode (LED) as a light source. Note that the above phrase "exhibits a sensitizing function by light with a wavelength of 400 nm or more" refers to having light absorption properties in the wavelength range of 400 nm or more. By using such a sensitizer, the ink composition of this embodiment can promote LED curing properties.

[0033] Examples of such sensitizers include anthracene-based sensitizers and thioxanthone-based sensitizers, and preferably thioxanthone-based sensitizers. These can be used alone or in combination of two or more kinds. Specific examples of the sensitizers include anthracene sensitizers such as 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, and 9,10-bis(2-ethylhexyloxy)anthracene, and thioxanthone sensitizers such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. Representative examples of commercially available products include anthracene sensitizers such as DBA and DEA (manufactured by Kawasaki Chemical Industries, Ltd.), and thioxanthone sensitizers such as DETX, ITX, and CPTX (manufactured by Lambson), and Omnipol TX (manufactured by IGM). The content of the sensitizer is preferably 0 to 8.0% by mass based on the total mass of the active energy ray-polymerizable component. If the content exceeds 8.0% by mass, no improvement in effect is observed, and it is undesirable because it becomes an excessive addition. When a thioxanthone-based sensitizer is used as the sensitizer, it tends to discolor the active energy ray-curable ink composition for inkjet printing to yellow, resulting in a hue that is more yellowish than the color (original hue) based on the pigment or the like. Therefore, it is preferable to appropriately determine the content of the thioxanthone-based sensitizer for each color. Specifically, in the white ink composition and the clear ink composition, which are susceptible to changes in color, it is preferable not to include a thioxanthone-based compound as a sensitizer. In addition, in the magenta ink composition and the cyan ink composition, changes in hue become a problem, so it is preferable to use a thioxanthone-based compound within a range in which no problems with hue occur. In addition, in the black ink composition and the yellow ink composition, since discoloration does not affect the hue and the active energy ray polymerizability is poorer than other hues, it is preferable to use a thioxanthone-based compound in combination as a sensitizer.

[0034]

[0113] It is also possible to use resins other than the above-mentioned acrylic resins in combination, as long as the performance of the active energy ray-curable ink composition for ink jet printing of the present invention is not impaired, such as vinyl chloride resins, vinyl chloride-vinyl acetate resins and ethylene-vinyl acetate resins, styrene-acrylic resins, styrene-maleic acid resins, rosin resins, rosin ester resins, petroleum resins, coumarone-indene resins, terpene phenol resins, phenol resins, ketone resins, urethane resins, melamine resins, urea resins, epoxy resins, cellulose resins, xylene resins, alkyd resins, aliphatic hydrocarbon resins, butyral resins, maleic acid resins, fumaric acid resins, and the like.

[0035] (Requirement H) As the colorant contained in the active energy ray-curable ink composition for inkjet printing of the present invention, known pigments and dyes that have been conventionally used in active energy ray-curable ink compositions for inkjet printing can be used, and color pigments such as organic color pigments and inorganic color pigments are preferred. As a result, active energy ray-curable ink compositions for inkjet printing of each color can be obtained.

[0036] Examples of organic coloring pigments include dye lake pigments, azo-based, benzimidazolone-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigo-based, thioindigo-based, perylene-based, perinone-based, diketopyrrolopyrrole-based, isoindolinone-based, nitro-based, nitroso-based, anthraquinone-based, flavanthrone-based, quinophthalone-based, pyranthrone-based, and indanthrone-based pigments. Inorganic color pigments include colored pigments such as titanium oxide, red ocher, antimony red, cadmium yellow, cobalt blue, ultramarine, Prussian blue, iron black, chromium oxide green, carbon black, and graphite (including achromatic color pigments such as white and black), and extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc.

[0037] Specific examples of the above color pigments for each representative hue are as follows: The yellow pigment is CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 42, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 108, 109, 114, 120, 128, 129, 138, 139, 150, 151, 155, 166, 180, 184, 185, 213, etc., and preferably CI Pigment Yellow 150, 155, 180, 213, etc. Magenta pigments include CI Pigment Red 5, 7, 12, 19, 22, 38, 48:1, 48:2, 48:4, 49:1, 53:1, 57, 57:1, 63:1, 101, 102, 112, 122, 123, 144, 146, 149, 168, 177, 178, 179, 180, 184, 185, 190, 202, 209, 224, 242, 254, 255, 270, CI Pigment Violet 19, and the like, and preferably CI Pigment Red 122, 202, CI Pigment Violet 19, and the like. 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., and preferably CI Pigment Blue 15:4, etc. The black pigment is carbon black (CI Pigment Black 7) or the like. The white pigment is titanium oxide, aluminum oxide, or the like, and is preferably titanium oxide or the like that has been surface-treated with various materials such as alumina or silica. The content of the colorant in the ink composition is preferably 1% by mass or more, and preferably 20% by mass or less in the ink composition. When the content of the colorant is within the above range, the ink composition provides suitable image quality in the resulting printed matter and has excellent viscosity characteristics.

[0038] (Pigment dispersant)

[0113] Examples of pigment dispersants that may be contained in the active energy ray-curable ink composition for ink jet printing of the present invention when it contains a pigment include ionic or nonionic surfactants, and anionic, cationic or nonionic polymer compounds. Among these, polymeric compounds are preferred, such as carbodiimide compounds described in JP-A-2004-083872, WO-A-2003 / 076527, and WO-A-2004 / 000950, and basic functional group-containing copolymers such as AJISPER PB821 and 822 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Solsperse 56000 (manufactured by Lubrizol), Solsperse 32000 (manufactured by Lubrizol), Solsperse 39000 (manufactured by Lubrizol), and DISPERBYK (manufactured by BYK Japan). These pigment dispersants can be used alone or in combination of two or more. Among these, a copolymer containing a basic functional group having an amine value of 10 to 40 mgKOH / g is preferred. The pigment dispersant is appropriately selected depending on the type of pigment and the type of organic solvent used.

[0039] (Organic solvent) The actinic radiation-curable ink composition for ink-jet printing of the present invention may be a so-called solventless type in which all liquid components are solidified by a curing reaction, or a solvent type in which the coating film after printing is dried to remove the solvent and then cured, provided that water is not used as a solvent. The case where an organic solvent is contained in the actinic ray-curable ink composition for ink-jet printing of the present invention will be described below. The organic solvent that may be contained in the actinic ray-curable ink composition for ink-jet printing of the present invention is propylene carbonate, diethylene glycol dialkyl ether, dipropylene glycol alkyl ether acetate, or the like.

[0040] As the diethylene glycol dialkyl ether, it is preferable to use diethylene glycol ethyl methyl ether and / or diethylene glycol diethyl ether, and further, another diethylene glycol dialkyl ether can be used in combination. As the dipropylene glycol alkyl ether acetate, preferably, an alkyl group having 6 or less carbon atoms, more preferably, an alkyl group having 3 or less carbon atoms, and even more preferably, an alkyl group having 2 or less carbon atoms can be used.

[0041] In order to adjust the drying property and further improve the prevention of mottling, an alkylene glycol derivative having a flash point of 50 to 150° C. can be used in combination with the diethylene glycol dialkyl ether. Examples of such alkylene glycol derivatives having a flash point of 50 to 150°C include (poly)ethylene glycol dialkyl ethers such as triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and tetraethylene glycol dimethyl ether; (poly)propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tetrapropylene glycol diethyl ether, and tetrapropylene glycol dimethyl ether; (poly)propylene glycol monoalkyl ethers such as propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether; and (poly)propylene glycol monoalkyl ethers such as propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, and dipropylene glycol monobutyl ether acetate. Alkyl ether monoalkyl esters, (poly)ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, and tetraethylene glycol monobutyl ether, (poly)ethylene glycol monoalkyl ether monoalkyl esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, and triethylene glycol monomethyl ether acetate, (poly)ethylene glycol diesters such as ethylene glycol diacetate, diethylene glycol diacetate, and triethylene glycol diacetate, and ethylene glycol monomethyl ether acetate,Examples of the monoether monoesters include (poly)ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether acetate, and triethylene glycol monobutyl ether acetate. Among alkylene glycol derivatives having a flash point of 50 to 150° C., diethylene glycol ethyl methyl ether and diethylene glycol diethyl ether can be mentioned first. Furthermore, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and the like, which have a flash point outside the range of 50 to 150°C, may be used in combination so long as the flash point of the entire solvent is not significantly changed.

[0042] (Other ingredients) Furthermore, in the active energy ray-curable ink composition for ink-jet printing of the present invention, various additives such as a surfactant, a plasticizer, a polymerization inhibitor, a surface conditioner, an ultraviolet protection agent, a light stabilizer, and an antioxidant can be used as necessary.

[0043] (Viscosity of active energy ray-curable ink composition for inkjet printing) The active energy ray-curable ink composition for ink jet printing of the present invention preferably has a viscosity of 30.0 mPa·s or less at 25° C. If the viscosity exceeds 30 mPa·s, it may become difficult to eject the ink composition from the ink jet printing nozzle. The viscosity was measured using an E-type viscometer (product name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.) at 25° C. and 20 rpm.

[0044] (Production of active energy ray-curable ink composition for inkjet printing) Next, a method for producing the actinic ray-curable ink composition for ink-jet printing of the present invention using these materials will be described. The active energy ray-curable ink composition for inkjet printing of the present invention can be obtained by dispersing and mixing using a dispersing machine such as a wet circulation mill, a bead mill, a ball mill, a sand mill, an attritor, a roll mill, a DCP mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a high-pressure homogenizer (such as Microfluidizer, Nanomizer, Ultimizer, Genus PY, or DeBEE2000), or a pearl mill, and adjusting the viscosity of the active energy ray-curable ink composition for inkjet printing to be 2 to 10 mPa s. The total content of the organic solvent in the actinic ray-curable ink composition for ink-jet printing of the present invention is the amount obtained by subtracting the total amount of each solid content and other additives used as necessary from the total amount of the ink composition, and it is preferable to appropriately change the content so that the ink viscosity falls within the above-mentioned range. The active energy ray-curable ink composition for inkjet printing of the present invention thus obtained can be used by an inkjet printer on a substrate having at least a surface layer made of paper or a resin such as a vinyl chloride polymer or an ethylene-vinyl acetate copolymer.

[0045] (Manufacturing method of printed matter) Next, a method for producing a printed matter using the active energy ray-curable ink composition for ink-jet printing of the present invention will be described. This production method includes a step of printing the above-described active energy ray-curable ink composition for ink jet printing onto a substrate by an ink jet method. The substrate is not particularly limited. For example, the substrate is a substrate such as a resin substrate, paper, capsule, gel, metal foil, glass, wood, or cloth, particularly a cardboard sheet. The ink composition of the present embodiment exhibits excellent bending resistance even when the substrate is folded after being printed on the substrate. Therefore, the ink composition is particularly suitable for use when the substrate is a substrate used for folding purposes such as a cardboard sheet. When the substrate is a cardboard sheet such as a C liner or a K liner, the ink composition may be applied directly to the cardboard sheet, or may be applied after providing a precoat layer (primer layer) on the cardboard sheet or performing a corona discharge treatment or the like. That is, in recent years, waste paper, recycled paper, etc. are sometimes used for cardboard sheets in consideration of the environment. When a K liner is used as the cardboard sheet, the surface has rough unevenness, the color is unclear, and the ink has high permeability when printed. Therefore, when the ink composition is printed on the cardboard sheet, the brown color of the liner base paper, which is the base, is likely to cause a decrease in print quality.

[0046] In particular, if the color of the base is expressed in the printed portion, the inkjet image will look dull and the appearance of the printed matter may be impaired. In order to eliminate the above-mentioned unevenness and the like, a precoat layer is appropriately provided on such corrugated board sheets. The precoat layer is provided for the purpose of adjusting the whiteness and color of the liner base paper constituting the corrugated cardboard sheet, increasing the whiteness of the base, etc. The precoat layer can be formed by applying a precoat agent containing a pigment and an adhesive. The pigment is not particularly limited. For example, the pigment may be titanium dioxide (anatase, rutile), aluminum hydroxide, barium sulfate, calcium carbonate, amorphous silica, clay, or other extender pigments. The content of the white pigment is preferably 20 to 85 parts by mass, more preferably 20 to 80 parts by mass, in 100 parts by mass of the precoat agent. The binder resin used in the precoat layer of the corrugated board is preferably an aqueous resin. The aqueous resin is preferably a natural resin, a synthetic resin, etc., and more preferably a starch derivative, casein, shellac, a polyvinyl alcohol derivative, an acrylic resin, or a maleic acid resin. More specifically, the aqueous resin is preferably an aqueous acrylic resin copolymerized with acrylic acid or methacrylic acid and its alkyl ester, or styrene as a main monomer component, an aqueous styrene-acrylic resin, an aqueous styrene-maleic acid resin, an aqueous styrene-acrylic acid-maleic acid resin, an aqueous polyurethane resin, an aqueous polyester resin, etc. The content of the binder resin is preferably 1 to 25 parts by mass, more preferably 1 to 15 parts by mass, in 100 parts by mass of the precoat agent.

[0047] The aqueous medium that can be used in the precoat layer (primer layer) can be water or a mixture of water and a water-miscible solvent. The water-miscible solvent can be lower alcohols, polyhydric alcohols, and their alkyl ethers or alkyl esters. Specifically, the water-miscible solvent can be lower alcohols such as methyl alcohol, ethyl alcohol, normal propyl alcohol, and isopropyl alcohol, polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoacetate, diethylene glycol monomethyl ether, and dipropylene glycol monomethyl ether. In addition to the components listed above, various additives such as film-forming agents, pigment dispersants or pigment dispersing resins, antiblocking agents, wetting agents, viscosity adjusters, pH adjusters, defoamers, and general surfactants may be appropriately selected and used in the precoat layer as necessary. The method of producing a precoat agent using these various materials is not particularly limited. As an example, a method of producing a precoat agent is generally a method of mixing and kneading a white pigment, an aqueous binder resin, water, a water-miscible solvent as required, and a pigment dispersant or a pigment dispersing resin, and further adding and mixing an additive, water, a water-miscible solvent as required, and the remaining predetermined materials. The precoat agent can be easily obtained by mixing the required amounts of the above components and mixing and dispersing them using a high-speed stirrer such as a homomixer or a lab mixer, or a disperser such as a three-roll mill or a bead mill. When a primer layer is provided, the thickness of the primer layer (the amount of the precoat agent applied) is not particularly limited. The primer layer has a solid content of 0.1 to 5 g / m 2 By having the thickness of the primer layer (amount of application of the precoat agent) within the above range, the whiteness and color of the corrugated cardboard sheet can be easily adjusted appropriately.

[0048]

[0043] Specific examples of the method for printing and curing the active energy ray-curable ink composition for inkjet printing of the present invention include a method in which the active energy ray-curable ink composition for inkjet printing of the present invention is ejected onto a substrate by an inkjet head, and then the coating film of the ink composition of the present invention that has landed on the substrate is exposed to light and cured. For example, ejection onto a substrate (printing of an image) can be performed by supplying the active energy ray-curable ink composition for inkjet printing of the present invention to a printer head compatible with low viscosity inks of an inkjet recording printer, and ejecting the ink composition from the printer head so that the coating film on the substrate has a thickness of, for example, 1 to 60 μm. Furthermore, exposure to light and curing (curing of an image) can be performed by irradiating the coating film of the active energy ray-curable ink composition for inkjet printing of the present invention, which has been applied onto a substrate as an image, with active energy rays. As a printer for inkjet recording that prints the active energy ray-curable ink composition for inkjet printing of the present invention, a printer for inkjet recording that has been conventionally used can be used. When a continuous type printer for inkjet recording is used, a conductivity imparting agent is further added to the active energy ray-curable ink composition for inkjet printing of the present invention to adjust the electrical conductivity. Examples of the active energy ray source for curing the coating film include ultraviolet rays (UV lamp), ultraviolet rays (light-emitting diode (LED)), electron beams, visible light, and the like. Specifically, the device may be, for example, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a mercury xenon lamp, a metal halide lamp, a high power metal halide lamp, a xenon lamp, a pulsed xenon lamp, a deuterium lamp, a fluorescent lamp, an Nd-YAG triple harmonic laser, a He-Cd laser, a nitrogen laser, a Xe-Cl excimer laser, a Xe-F excimer laser, a semiconductor excited solid state laser, an LED lamp, and the like. From an environmental standpoint, a light-emitting diode (LED) that generates ultraviolet rays with an emission peak wavelength in the range of 350 to 420 nm is preferable. The ultraviolet light emitted from a light-emitting diode (LED) as a light source is defined as "light emitted from a light-emitting diode that generates ultraviolet light with an emission peak wavelength in the range of 350 to 420 nm." The temperature of the ink composition during printing may be room temperature, about 20 to 26° C., or other temperatures. EXAMPLES

[0049] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass." The materials used in the following Examples and Comparative Examples are as follows. The units of values ​​in the columns for pigment, dispersant, resin, solvent and total in the tables are "mass %".

[0050] (Pigments) PY155: Pigment Yellow 155 PV19: Pigment Violet 19 PB15:4: Pigment Blue 15:4 P.Bl.7: Pigment Black 7 PG7: Pigment Green 7 PO13: Pigment Orange 13 PV23: Pigment Violet 23 PY150: Pigment Yellow 150 (Pigment dispersant) PB822 (Ajisper PB822, Ajinomoto Fine-Techno Co., Ltd.)

[0051] (Amine modified oligomer) CN371 (Sartomer) (Photopolymerization initiator) TPO: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide TPO-L: Ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide ESACURE ONE: Oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} SB-PI719: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide Omnipol TP (IGM) (sensitizer) DETX: Diethylthioxanthone (Lambson) Omnipol TX (IGM) (Polymerization inhibitor) MEHQ (hydroquinone monomethyl ether) HQ (hydroquinone) (Surface conditioner) BYK-331: Silicone Surfactant

[0052] (Examples 1 to 11, Comparative Examples 1 to 5) <Production of active energy ray-curable ink composition for inkjet printing> According to the formulation in Table 1 (the formulation ratio of each material is in mass %), after stirring and mixing each material, it was kneaded to obtain pigment dispersion liquids of various colors. Then, according to the formulation in Table 2, ink compositions for active energy ray-curable inkjet printing of Examples and Comparative Examples were obtained.

[0053] <Corrugated board substrate> K-liner, C-liner <Primer> 45 parts by mass of calcium carbonate with an average particle diameter of 0.05 μm, 25 parts by mass of a styrene maleic acid resin with an acid value of 170 mg KOH / g (solid content 25%), and 30 parts by mass of water were dispersed in a bead mill to obtain a 45% slurry of calcium carbonate. 80 parts by mass of the 45% slurry of calcium carbonate and 20 parts by mass of a styrene-maleic acid resin with an acid value of 170 mg KOH / g (solid content 25%) were mixed and stirred to obtain a primer. <Coating of the primer on the K-liner> The primer adjusted above was applied to the K-liner using a 0.1 mm Mayer bar so that the coating amount was about 4 g / m 2 of the coating amount. Then, the drying of the primer-coated surface was carried out by hot air drying.

[0054] <Evaluation method and evaluation criteria> The evaluation criteria described in Table 2 are as follows. (Viscosity) The viscosities of the active energy ray-curable inkjet printing ink compositions obtained in Examples and Comparative Examples were measured using an E-type viscometer (trade name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.) under the conditions of a temperature of 25 °C and a rotor rotation speed of 20 rpm.

[0055] (Coating film odor) After forming and curing a coating film on the substrate so that the coating film size became 8 cm × 12 cm, the substrate was put into a chuck bag of 24 cm × 34 cm, and the odor inside the bag was confirmed after one hour. Ten people were asked to smell it and evaluate it in the following five grades. The table shows the average value of the ten people rounded off to the decimal point. 5: Odorless 4: Low odor 3: Medium odor 2: Strong odor 1: Extremely stinky

[0056] (Storage stability) The actinic ray-curable ink composition for ink-jet printing was placed in a glass bottle, sealed, and stored at 70° C. for 7 days, after which the condition was evaluated according to the following evaluation criteria. ◯: Neither thickening nor sedimentation was observed in the actinic ray-curable ink composition for ink-jet printing. Δ: The actinic energy ray-curable ink composition for ink-jet printing showed increased viscosity and precipitates, which returned to their original state when lightly shaken. ×: The actinic energy ray-curable ink composition for ink-jet printing showed thickening or sedimentation to such an extent that it could not be restored even by vigorously shaking.

[0057] (Discharge stability) An inkjet recording device equipped with an inkjet nozzle and an active energy ray curable ink composition for inkjet printing were placed in an atmosphere at 25° C. for 24 hours, and the temperatures of the inkjet recording device and the active energy ray curable ink composition for inkjet printing were adjusted to 25° C. Thereafter, the ink composition was used to continuously print (print) on a K liner and a C liner on which a precoat had been applied at 25° C., and the ejection stability was evaluated according to the following evaluation criteria. ◯: There was no disturbance in printing and the ink was discharged stably. △: There was some disturbance in the printing, but the ink was discharged almost stably. ×: Printing was disturbed or ink could not be ejected stably.

[0058] (curable) An inkjet recording device equipped with an inkjet nozzle and an active energy ray curable ink composition for inkjet printing were placed in an atmosphere at 25° C. for 24 hours, and the temperatures of the inkjet recording device and the active energy ray curable ink composition for inkjet printing were set to 25° C. Thereafter, at 25° C., the ink composition was used to continuously print on a K liner and a C liner to which a precoat had been applied, and then the ink composition was exposed to a UV-LED light lamp manufactured by Phoseon Technology, Inc., at a distance of 2 cm between the lamp and the ink application surface, with a UV cumulative light amount of 180 mJ / cm. 2 Then, using a conveyor-type light irradiation device (Heraeus STM-250E-16, lamp: Z-8 lamp (metal halide type)), the resin was cured at 120 W x 50 m / min with a UV cumulative light dose of 75 mJ / cm. 2 [The UV integrated light amount was determined by measuring the amount of irradiation at the measurement ranges of 250-260 nm, 280-320 nm, 320-390 nm, and 395-445 nm using a UVIMAP (UM 365H-S) manufactured by EIT Co., Ltd.] The obtained curable coating film was rubbed with a cotton swab, and the curability was evaluated based on the degree of removal according to the following evaluation criteria. ○: There was no take. △: There was a slight takeover. ×: There was a takeover.

[0059] (hardening wrinkles) The ink composition was printed on the K liner and C liner to which the precoat had been applied, and the printed sample was visually evaluated for the presence of hardening wrinkles. ○: No hardening wrinkles. ×: Curing wrinkles are present.

[0060] (Bending resistance) An ink composition was printed on the precoat layer of a K liner and a C liner, each of which had a precoat layer formed on one side, and the liner was folded 90 degrees so that the printed surface was facing outward (so that the back sides of the K liner and C liner, not the printed sides, faced each other), and evaluated according to the evaluation criteria below. ◯: When folded, no creases or fine cracks were observed in the coating film. △: Fine cracks occurred when bent. ×: Creases occurred when folded.

[0061] (Abrasion resistance) The cured films obtained in the above curability evaluation were visually observed for the degree to which the cured film was removed from the K liner and C liner to which the precoat was applied when the coating film was rubbed 200 times with 500 g of bleached cloth using a Gakushin type fastness tester (manufactured by Daiei Scientific Instruments Manufacturing Co., Ltd.), and evaluated according to the following evaluation criteria. ◯: The cured film was not removed. △: There were scratches on the surface of the cured film. ×: The cured film was removed and the sheet was visible.

[0062] (water resistance) The cured films obtained in the above curability evaluation were visually observed for the degree to which the cured film was removed from the K liner and C liner to which the precoat was applied when the coating film was rubbed 30 times with 500 g of water-soaked bleached cloth using a Gakushin type fastness tester (manufactured by Daiei Scientific Instruments Manufacturing Co., Ltd.), and evaluated according to the following evaluation criteria. ◯: The cured film was not removed. △: There were scratches on the surface of the cured film. ×: The cured film was removed and the sheet was visible.

[0063] (Biomass ratio) The biomass degree is calculated using the following formula: (Content of vegetable oil components in the solid content of the active energy ray curable ink jet printing ink composition / Solid content of the active energy ray curable ink jet printing ink composition)×100

[0064] [Table 1]

[0065] [Table 2-1]

[0066] [Table 2-2]

[0067]

[0113] According to each of the examples which are examples in accordance with the present invention, an active energy ray-curable ink composition for inkjet printing was obtained which has a low viscosity, is odorless, has excellent storage stability, ejection stability and curing properties, does not produce curing wrinkles upon curing, and provides a cured coating film which is excellent in bending resistance, abrasion resistance and water resistance, and has a high biomass degree. However, Comparative Example 1, which did not contain the amine-modified oligomer and contained an excess of the component of requirement D, was inferior in curability, bending resistance, and abrasion resistance, and Comparative Example 2, which contained an excess of the amine-modified oligomer and too little of the component of requirement D, was high in viscosity and had poor storage stability and ejection stability. Comparative Example 3, which had a low content of the component satisfying requirement C, had poor bending resistance, and Comparative Example 4, which had an excessive content of the component satisfying requirement C, had poor storage stability, developed hardening wrinkles, and had poor abrasion resistance. Moreover, according to Comparative Example 5 in which the component satisfying requirement B was excessive, the coating film had poor water resistance.

Claims

1. An active energy ray-curable ink composition for inkjet printing, which satisfies the following requirements A to E and has a total content of compounds (D) and (E) of 30.0 to 60.0 mass % in the active energy ray-curable ink composition for inkjet printing: (A) an acrylated amine compound having two photopolymerizable functional groups and two amino groups in the molecule is contained in an amount of 1.0 to 20.0 mass % in an active energy ray-curable ink composition for inkjet printing; (B) an alkoxy group-containing (meth)acrylate monomer is contained in an amount of 2.0 to 20.0% by mass in the active energy ray-curable ink composition for inkjet printing; (C) a (meth)acrylate monomer having an alkyl group having 10 to 20 carbon atoms is contained in an amount of 2.0 to 25.0% by mass in the active energy ray-curable ink composition for inkjet printing; (D) at least one selected from the group consisting of 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, propoxylated (2) neopentyl glycol diacrylate, and hydroxypivalic acid neopentyl glycol diacrylate is contained in an amount of 5.0 to 25.0% by mass in the active energy ray-curable ink composition for inkjet printing; (E) The active energy ray-curable ink composition for inkjet printing contains 10.0 to 40.0% by mass of 1,10-decanediol diacrylate derived from vegetable oil.

2. 2. The actinic ray-curable ink composition for ink-jet printing according to claim 1, wherein 50 to 100 mass % of the (meth)acrylate monomer having an alkoxy group of (B) is a polyfunctional alkoxy (meth)acrylate monomer.

3. The actinic ray-curable ink composition for ink-jet printing according to claim 1 or 2, further comprising (F) a photopolymerization initiator.

4. (F) a photopolymerization initiator, 2,4,6-trimethylbenzyl-diphenylphosphine oxide Ethoxy(2,4,6-trimethylbenzoyl)phenylphosphine oxide Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide Oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} Polymer type initiator bis[4-(2-hydroxy-2-methylpropanoyl)phenyl]ether, 4. The actinic ray-curable ink composition for ink-jet printing according to claim 1, wherein the active energy ray-curable ink composition for ink-jet printing according to claim 2 is at least one selected from the group consisting of 1) to 3).

5. The active energy ray-curable ink composition for inkjet printing according to any one of claims 1 to 4, wherein the active energy ray-curable ink composition for inkjet printing contains (G) a (meth)acrylate monomer having a hydroxyl group in an amount of 3.0 to 20.0 mass %.

6. 6. The active energy ray-curable ink composition for ink-jet printing according to any one of claims 1 to 5, wherein (C) the (meth)acrylate monomer having an alkyl group having 10 to 20 carbon atoms is lauryl acrylate derived from vegetable oil.

7. The actinic ray-curable ink composition for ink-jet printing according to any one of claims 1 to 6, further comprising (H) a colorant.

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