Active energy ray-curable inkjet ink, image recording method and method for producing molded article

Abstract

To provide an active energy ray-curable inkjet ink and the like which can obtain an image recorded material having excellent impact resistance and blocking resistance.SOLUTION: There is provided an active energy ray-curable inkjet ink which contains a bifunctional (meth)acrylate having a linear or branched alkylene group having a carbon number of 5 to 9, a benzyl (meth)acrylate and a colorant, wherein the total content of the bifunctional (meth)acrylate and the benzyl (meth)acrylate is 60 mass% or more based on the total amount of the active energy ray-curable inkjet ink.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to an actinic energy ray-curable inkjet ink, an image recording method, and a method for producing a molded article. [Background technology]

[0002] 2. Description of the Related Art Conventionally, when an image is recorded on a substrate using ink, a method of curing the ink using active energy rays has been known.

[0003] For example, Patent Document 1 describes an image forming ink containing a photopolymerizable monomer and a photopolymerization initiator, and Patent Document 2 describes an active energy ray-curable inkjet ink containing a polymerizable compound. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-1676 A [Patent Document 2] JP 2017-25124 A Summary of the Invention [Problem to be solved by the invention]

[0005] 2. Description of the Related Art In some cases, an image recorded by applying an ink onto a substrate is required to have excellent impact resistance and blocking resistance.

[0006] The present disclosure has been made in consideration of the above circumstances, and an object of one embodiment of the present invention is to provide an actinic ray-curable inkjet ink that can provide an image recorded with excellent impact resistance and blocking resistance. Another object of the present invention is to provide an image recording method using the above-mentioned active energy ray-curable ink-jet ink, and a method for producing a molded article. [Means for solving the problem]

[0007] The present disclosure includes the following aspects. <1> The composition includes a bifunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms, a benzyl (meth)acrylate, and a colorant, An active energy ray-curable inkjet ink, wherein the total content of the bifunctional (meth)acrylate and the benzyl (meth)acrylate is 60 mass % or more based on the total amount of the active energy ray-curable inkjet ink. <2> The total content of the bifunctional (meth)acrylate and the benzyl (meth)acrylate is 95 mass% or more based on the total amount of the polymerizable compounds. <1> 13. The actinic ray-curable ink-jet ink according to claim 12. <3> the mass ratio of the content of benzyl (meth)acrylate to the content of bifunctional (meth)acrylate is 2.0 to 5.0; <1> or <2> 13. The actinic ray-curable ink-jet ink according to claim 12. <4> The content of benzyl (meth)acrylate is 50% by mass or more based on the total amount of the active energy ray-curable inkjet ink. <1> ~ <3> 10. The actinic ray-curable ink-jet ink according to claim 9, <5> The surface tension is 23mN / m~26mN / m. <1> ~ <4> 10. The actinic ray-curable ink-jet ink according to claim 9, <6> Further comprising a silicone surfactant, <1> ~ <5> 10. The actinic ray-curable ink-jet ink according to claim 9, <7> The silicone surfactant contains a polyether structure and a polysiloxane structure, The mass ratio of the content of the polysiloxane structure to the content of the polyether structure is 0.6 or less. <6> 13. The actinic ray-curable ink-jet ink according to claim 12. <8> On the substrate, <1> ~ <7> applying the active energy ray-curable inkjet ink according to any one of the above items by an inkjet recording method; and a step of irradiating the applied actinic energy ray-curable inkjet ink with actinic energy rays to record an image. <9> On the substrate, <1> ~ <7> applying the active energy ray-curable inkjet ink according to any one of the above items by an inkjet recording method; a step of irradiating the applied active energy ray-curable inkjet ink with active energy rays to record an image; and forming the substrate having the image recorded thereon to form a molded article. Effect of the Invention

[0008] According to one embodiment of the present invention, there is provided an actinic ray-curable inkjet ink capable of obtaining an image recorded product having excellent impact resistance and blocking resistance. According to other embodiments of the present invention, there are provided an image recording method using the above-mentioned active energy ray-curable ink-jet ink, and a method for producing a molded article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The active energy ray-curable inkjet ink and the method for producing a molded article according to the present disclosure will be described in detail below.

[0010] In this specification, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in a certain numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0011] In this specification, the amount of each component in a composition means the total amount of multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified. As used herein, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0012] In this specification, the term "image" generally refers to a film formed by applying ink, and the term "image recording" refers to the formation of an image (that is, a film). Additionally, the concept of "image" in this specification also includes a solid image.

[0013] In this specification, the term "(meth)acrylate" is a concept that encompasses both acrylate and methacrylate, and the term "(meth)acrylic" is a concept that encompasses both acrylic and methacrylic.

[0014] An active energy ray-curable inkjet ink (hereinafter also simply referred to as "ink") according to one embodiment of the present disclosure contains a bifunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms, benzyl (meth)acrylate, and a colorant, and the total content of the bifunctional (meth)acrylate and benzyl (meth)acrylate is 60 mass% or more based on the total amount of the ink.

[0015] For example, the ink according to an embodiment of the present disclosure is applied onto a substrate, and then an active energy ray is irradiated to obtain an image recording material in which an ink film is formed on the substrate as an image. The ink according to an embodiment of the present disclosure contains a bifunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms, and benzyl (meth)acrylate, and therefore a polymerization reaction proceeds upon irradiation with active energy rays. The benzyl (meth)acrylate and the bifunctional (meth)acrylate contribute to achieving both impact resistance and blocking resistance, and in particular, the total content of the bifunctional (meth)acrylate and benzyl (meth)acrylate is 60 mass% or more relative to the total amount of the ink, so that the ink is considered to have excellent impact resistance and blocking resistance.

[0016] On the other hand, Patent Documents 1 and 2 do not anticipate the inclusion of the bifunctional (meth)acrylate and benzyl (meth)acrylate, with the total content being 60 mass % or more relative to the total amount of the ink.

[0017] Hereinafter, each component contained in the ink according to an embodiment of the present disclosure will be described.

[0018] [Active energy beam curable inkjet ink] The ink according to an embodiment of the present disclosure is an active energy ray curable ink. That is, the ink according to an embodiment of the present disclosure is cured by irradiation with active energy rays. Examples of active energy rays include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light rays. Of these, the active energy rays are preferably ultraviolet rays. The ink according to an embodiment of the present disclosure is preferably an ultraviolet ray curable ink.

[0019] <Bifunctional (meth)acrylate having linear or branched alkylene group having 5 to 9 carbon atoms> The ink according to one embodiment of the present disclosure contains a difunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms (hereinafter also referred to as a "specific difunctional (meth)acrylate").

[0020] The bifunctional (meth)acrylate means a compound having two (meth)acryloyloxy groups.

[0021] The specific bifunctional (meth)acrylate has a linear or branched alkylene group having 5 to 9 carbon atoms, and therefore the resulting image has excellent blocking resistance.

[0022] From the same viewpoint, the linear or branched alkylene group preferably has 6 to 8 carbon atoms, and more preferably has 6 carbon atoms.

[0023] The ink may contain only one type of specific bifunctional (meth)acrylate, or two or more types of specific bifunctional (meth)acrylate.

[0024] Examples of the specific bifunctional (meth)acrylate include 3-methyl-1,5-pentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol diacrylate, 1,7-heptanediol diacrylate, 1,8-octanediol diacrylate, and 1,9-nonanediol di(meth)acrylate.

[0025] Among them, from the viewpoint of ejection properties, the specific bifunctional (meth)acrylate is preferably at least one selected from the group consisting of 3-methyl-1,5-pentanediol di(meth)acrylate and 1,6-hexanediol diacrylate, and more preferably 3-methyl-1,5-pentanediol di(meth)acrylate.

[0026] From the viewpoint of blocking resistance, the content of the specific bifunctional (meth)acrylate is preferably 15% by mass to 40% by mass, and more preferably 17% by mass to 25% by mass, based on the total amount of the ink.

[0027] <Benzyl (meth)acrylate> In one embodiment of the present disclosure, the ink comprises benzyl (meth)acrylate.

[0028] From the viewpoint of impact resistance, the content of benzyl (meth)acrylate is preferably 50% by mass or more, more preferably 50% by mass to 70% by mass, and even more preferably 55% by mass to 65% by mass, relative to the total amount of the ink.

[0029] From the viewpoint of further improving the impact resistance and blocking resistance, the mass ratio of the content of benzyl (meth)acrylate to the content of the specific bifunctional (meth)acrylate is preferably from 2.0 to 5.0, and more preferably from 2.0 to 4.0.

[0030] <Other polymerizable compounds> The ink according to an embodiment of the present disclosure may contain polymerizable compounds other than the specific bifunctional (meth)acrylate and benzyl (meth)acrylate, as long as the effects of the present disclosure are not significantly impaired. However, from the viewpoint of impact resistance and blocking resistance, it is desirable that the content of other polymerizable compounds is small.

[0031] Specifically, the total content of the specific bifunctional (meth)acrylate and benzyl (meth)acrylate is preferably 95% by mass or more, more preferably 98% by mass or more, based on the total amount of the polymerizable compounds. The polymerizable compounds referred to here refer to all the polymerizable compounds contained in the ink. From the above viewpoint, the total content of the specific bifunctional (meth)acrylate and benzyl (meth)acrylate may be 100% by mass, based on the total amount of the polymerizable compounds.

[0032] When the ink contains another polymerizable compound, the another polymerizable compound is not particularly limited as long as it is a compound other than the specific bifunctional (meth)acrylate and benzyl (meth)acrylate and has a polymerizable group.

[0033] From the viewpoint of reactivity with the specific bifunctional (meth)acrylate and benzyl (meth)acrylate, the polymerizable group in the other polymerizable compound is preferably a radical polymerizable group, more preferably an ethylenically unsaturated group, and even more preferably a (meth)acryloyloxy group. That is, the other polymerizable compound is preferably a radical polymerizable compound, more preferably an ethylenically unsaturated compound, and even more preferably a (meth)acrylate compound.

[0034] The other polymerizable compound may be a monofunctional polymerizable compound having one polymerizable group, or a polyfunctional polymerizable compound having two or more polymerizable groups.

[0035] -Monofunctional polymerizable compound- Examples of the monofunctional polymerizable compound include monofunctional (meth)acrylates, monofunctional (meth)acrylamides, monofunctional aromatic vinyl compounds, monofunctional vinyl ethers, and monofunctional N-vinyl compounds.

[0036] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tert-octyl (meth)acrylate, isoamyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, and cyclohexyl (meth)acrylate. , 4-n-butylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, butoxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, 4-bromobutyl (meth)acrylate, cyanoethyl (meth)acrylate, butoxymethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate , 2-(2-butoxyethoxy)ethyl (meth)acrylate, 2,2,2-tetrafluoroethyl (meth)acrylate, 1H,1H,2H,2H-perfluorodecyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-tetramethylphenyl (meth)acrylate, 4-chlorophenyl (meth)acrylate, 2-phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, glycidyloxybutyl (meth)acrylate , glycidyloxyethyl (meth)acrylate, glycidyloxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, phenyl glycidyl ether (meth)acrylate,Dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, trimethylsilylpropyl (meth)acrylate, polyethylene oxide monomethyl ether (meth)acrylate, polyethylene oxide (meth)acrylate, polyethylene oxide monoalkyl ether (meth)acrylate, dipropylene glycol (meth)acrylate, polypropylene oxide monoalkyl ether (meth)acrylate, 2-methacryloyloxyethyl succinate, 2-methacryloyloxyhexahydrophthalate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, ethoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate ) acrylate, trifluoroethyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, ethylene oxide (EO) modified phenol (meth)acrylate, EO modified cresol (meth)acrylate, EO modified nonylphenol (meth)acrylate, propylene oxide (PO) modified nonylphenol (meth)acrylate, EO modified 2-ethylhexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, (3-ethyl-3-oxetanylmethyl) (meth)acrylate, phenoxyethylene glycol (meth)acrylate, 2-carboxyethyl (meth)acrylate and 2-(meth)acryloyloxyethyl succinate.

[0037] Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, Nn-butyl(meth)acrylamide, Nt-butyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-methylol(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and (meth)acryloylmorpholine.

[0038] Examples of monofunctional aromatic vinyl compounds include styrene, dimethylstyrene, trimethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, vinyl benzoic acid methyl ester, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4-hexylstyrene, 3-octylstyrene, 4-octylstyrene, 3-(2-ethylhexyl)styrene, 4-(2-ethylhexyl)styrene, allylstyrene, isopropenylstyrene, butenylstyrene, octenylstyrene, 4-t-butoxycarbonylstyrene, and 4-t-butoxystyrene.

[0039] Examples of monofunctional vinyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-methylcyclohexylmethyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexylmethyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, and phenoxypolyethylene glycol vinyl ether.

[0040] Examples of monofunctional N-vinyl compounds include N-vinyl-ε-caprolactam and N-vinylpyrrolidone.

[0041] -Multifunctional polymerizable compound- Examples of the polyfunctional polymerizable compound include polyfunctional (meth)acrylate compounds and polyfunctional vinyl ethers.

[0042] Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, EO-modified neopentyl glycol di(meth)acrylate, PO-modified neopentyl glycol di(meth)acrylate, EO-modified hexanediol di(meth)acrylate, PO-modified hexanediol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, and glycerin di(meth)acrylate. Examples of the acrylates include acrylates of 2-(2-methyl-1,2-dimethylphenyl)-2-propanediol, acrylates of 1,2-dimethylphenyl ...

[0043] Examples of polyfunctional vinyl ethers include 1,4-butanediol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, and ditrimethylolpropane trivinyl ether. Examples of the vinyl ethers include ethylenediaminetetravinyl ether, ...

[0044] <Coloring agent> The inks of one embodiment of the present disclosure contain at least one colorant.

[0045] In the present disclosure, a colorant refers to a substance that, when contained in an ink, can make the ink a chromatic or achromatic ink.

[0046] The colorant may be a chromatic (eg, cyan, magenta, yellow, etc.) colorant or an achromatic (eg, white and black) colorant.

[0047] The colorant may be a dye or a pigment. From the viewpoint of durability such as heat resistance, light resistance, and water resistance, the colorant is preferably a pigment.

[0048] When a pigment is used as a colorant, the pigment can be contained in the ink as a pigment dispersion. The pigment dispersion is a liquid obtained by dispersing a pigment in a liquid medium using a dispersant, and contains at least a pigment, a dispersant, and a liquid medium. Details of the dispersant will be described later. The liquid medium may be an organic solvent or a polymerizable compound.

[0049] As the pigment, any of organic pigments and inorganic pigments that are usually commercially available can be used. Examples of the pigment include those described in "Dictionary of Pigments" edited by Seijiro Ito (published in 2000), "Industrial Organic Pigments" by W. Herbst and K. Hunger, and in JP-A Nos. 2002-12607, 2002-188025, 2003-26978, and 2003-342503.

[0050] The content of the colorant is preferably 0.5% by mass to 15% by mass, more preferably 1% by mass to 10% by mass, and even more preferably 2% by mass to 5% by mass, based on the total amount of the ink.

[0051] <Dispersant> When a pigment is used as the colorant, the pigment can be contained in the ink as a pigment dispersion. The pigment can be dispersed in a liquid medium using a dispersant. As the dispersant, a commonly known dispersant can be used. From the viewpoint of dispersion stability, the dispersant is preferably a compound having both a hydrophilic structure and a hydrophobic structure.

[0052] Examples of dispersants include low molecular weight dispersants having a molecular weight of less than 1000, such as higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, sulfosuccinates, naphthalene sulfonates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkyl phenyl ethers, polyoxyethylene polyoxypropylene glycols, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene fatty acid amides, and amine oxides.

[0053] The dispersant may be a high molecular weight dispersant having a molecular weight of 1000 or more obtained by copolymerizing a hydrophilic monomer and a hydrophobic monomer. From the viewpoint of dispersion stability, the hydrophilic monomer is preferably a dissociable group-containing monomer, and is preferably a dissociable group-containing monomer having a dissociable group and an ethylenically unsaturated bond. Examples of the dissociable group-containing monomer include a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, and a phosphoric acid group-containing monomer. From the viewpoint of dispersion stability, the hydrophobic monomer is preferably an aromatic group-containing monomer having an aromatic group and an ethylenically unsaturated bond, or an aliphatic hydrocarbon group-containing monomer having an aliphatic hydrocarbon group and an ethylenically unsaturated bond. The polymer may be either a random copolymer or a block copolymer.

[0054] The dispersant may be a commercially available product. Examples of commercially available products include DISPERBYK-101, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-110, DISPERBYK-111, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-164, DISPERBYK-166, DISPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-182 (all manufactured by BYK Chemie); and SOLSPERSE3000, SOLSPERSE5000, SOLSPERSE9000, SOLSPERSE12000, SOLSPERSE13240, SOLSPERSE13940, SOLSPERSE17000, SOLSPERSE22000, SOLSPERSE24000, SOLSPERSE26000, SOLSPERSE28000, SOLSPERSE32000, SOLSPERSE36000, SOLSPERSE39000, SOLSPERSE41000, SOLSPERSE71000 (all manufactured by Lubrizol) Examples include:

[0055] As a dispersing device for dispersing the pigment, a known dispersing device can be used, and examples thereof include a ball mill, a sand mill, a bead mill, a roll mill, a jet mill, a paint shaker, an attritor, an ultrasonic disperser, and a disperser.

[0056] From the viewpoint of dispersion stability, the content of the dispersant relative to the content of the pigment in the ink is preferably 0.05 to 1.0 by mass, and more preferably 0.1 to 0.5.

[0057] <Surfactant> The ink of the present disclosure preferably contains at least one surfactant.

[0058] Examples of the surfactant include silicone-based surfactants, acetylene glycol-based surfactants, and polyoxyethylene alkyl ether-based surfactants.

[0059] The ink of the present disclosure preferably contains at least one silicone-based surfactant. The silicone surfactant reduces the surface tension of the ink and improves the wettability of the ink to the substrate or the undercoat layer formed on the substrate, thereby improving the quality of the resulting image.

[0060] Among them, the silicone surfactant is preferably a silicone surfactant having a (meth)acryloyl group.

[0061] When the ink contains a silicone surfactant having a (meth)acryloyl group, a polymerization reaction with the specific bifunctional (meth)acrylate and benzyl (meth)acrylate proceeds, improving impact resistance and blocking resistance.

[0062] The number of (meth)acryloyl groups contained in the silicone surfactant having a (meth)acryloyl group may be only one, or may be two or more. From the viewpoint of separability, the number of (meth)acryloyl groups is preferably 2 or more, and more preferably 3 or more. The upper limit of the number of (meth)acryloyl groups is not particularly limited, but is, for example, 5 from the viewpoint of ejection property.

[0063] The silicone surfactant having a (meth)acryloyl group is preferably a polyether-modified polydimethylsiloxane having a (meth)acryloyl group. In the polyether-modified polydimethylsiloxane having a (meth)acryloyl group, the position of the polyether chain is not particularly limited, and may be at one end of the main chain, at both ends of the main chain, or in a side chain. The polyether chain is preferably a polyoxyalkylene chain.

[0064] Commercially available silicone surfactants having a (meth)acryloyl group include, for example, BYK-UV3500, 3505, 3530, 3570, 3575, and 3576 (manufactured by BYK), Tegorad 2100, 2200, 2250, 2300, 2500, 2600, 2700, 2800, 2010, and 2011 (manufactured by Evonik), EBECRYL 350 and 1360 (manufactured by Daicel-Allnex), and KP-410, 411, 412, 413, 414, 415, 416, 418, 420, 422, and 423 (manufactured by Shin-Etsu Silicones).

[0065] The silicone surfactant contains a polyether structure and a polysiloxane structure, and the mass ratio of the content of the polysiloxane structure to the content of the polyether structure is preferably 0.6 or less, more preferably 0.4 or less. The lower limit of the mass ratio is, for example, 0.2.

[0066] When the mass ratio is 0.6 or less, when an overcoat layer is provided on an image, it is possible to suppress repelling of the overcoat liquid used to form the overcoat layer on the image surface.

[0067] The mass ratio of the polysiloxane structure content to the polyether structure content was determined by nuclear magnetic resonance spectroscopy (NMR; 1 H-NMR).

[0068] The content of the surfactant is preferably 0.01% by mass to 5% by mass, and more preferably 0.05% by mass to 2% by mass, relative to the total amount of the ink.

[0069] <Polymerization initiator> The ink according to an embodiment of the present disclosure may contain at least one polymerization initiator. The polymerization initiator is preferably a radical polymerization initiator that generates radicals.

[0070] Examples of the radical polymerization initiator include an alkylphenone compound, an acylphosphine compound, an aromatic onium salt compound, an organic peroxide, a thio compound, a hexaarylbiimidazole compound, a ketoxime ester compound, a borate compound, an azinium compound, a metallocene compound, an active ester compound, a compound having a carbon-halogen bond, and an alkylamine compound.

[0071] Among these, the polymerization initiator is preferably at least one selected from the group consisting of an acylphosphine compound and a thio compound, more preferably at least one selected from the group consisting of an acylphosphine oxide compound and a thioxanthone compound, and even more preferably a combination of an acylphosphine oxide compound and a thioxanthone compound.

[0072] The acylphosphine oxide compound includes a monoacylphosphine oxide compound and a bisacylphosphine oxide compound.

[0073] Examples of the monoacylphosphine oxide compound include isobutyryldiphenylphosphine oxide, 2-ethylhexanoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, o-toluyldiphenylphosphine oxide, pt-butylbenzoyldiphenylphosphine oxide, 3-pyridylcarbonyldiphenylphosphine oxide, acryloyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid vinyl ester, acryloyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide ... Examples of the diphenylphosphine oxide include dipoylbisdiphenylphosphine oxide, pivaloyldiphenylphosphine oxide, p-toluyldiphenylphosphine oxide, 4-(t-butyl)benzoyldiphenylphosphine oxide, terephthaloylbisdiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, versatoyldiphenylphosphine oxide, 2-methyl-2-ethylhexanoyldiphenylphosphine oxide, 1-methyl-cyclohexanoyldiphenylphosphine oxide, pivaloylphenylphosphine acid methyl ester, and pivaloylphenylphosphine acid isopropyl ester.

[0074] Examples of the bisacylphosphine oxide compound include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-ethoxyphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2-naphthylphosphine oxide, and bis(2,6-dichlorobenzoyl). phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dimethoxyphenylphosphine oxide, bis(2,6-dichlorobenzoyl)decylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-octylphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-2, 5-Dimethylphenylphosphine oxide, bis(2,6-dichloro-3,4,5-trimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichloro-3,4,5-trimethoxybenzoyl)-4-ethoxyphenylphosphine oxide, bis(2-methyl-1-naphthoyl)-2,5-dimethylphenylphosphine oxide, bis(2-methyl-1-naphthoyl)-4-ethoxyphenylphosphine oxide, bis(2-methyl-1-naphthoyl)-2- naphthylphosphine oxide, bis(2-methyl-1-naphthoyl)-4-propylphenylphosphine oxide, bis(2-methyl-1-naphthoyl)-2,5-dimethylphenylphosphine oxide, bis(2-methoxy-1-naphthoyl)-4-ethoxyphenylphosphine oxide, bis(2-chloro-1-naphthoyl)-2,5-dimethylphenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0075] Thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)thioxanthone, 4-butoxycarbonylthioxanthone, and 5-methylthioxanthone. 1-Butoxycarbonyl-7-methylthioxanthone, 1-Cyano-3-chlorothioxanthone, 1-Ethoxycarbonyl-3-chlorothioxanthone, 1-Ethoxycarbonyl-3-ethoxythioxanthone, 1-Ethoxycarbonyl-3-aminothioxanthone, 1-Ethoxycarbonyl-3-phenylsulfurylthioxanthone, 3,4-Di[2-(2-methoxyethoxy)ethoxycarbonyl]thioxanthone, 1-Ethoxycarbonyl-3-phenylsulfurylthioxanthone, 3,4-Di[2-(2-methoxyethoxy)ethoxycarbonyl]thioxanthone, 2-Methyl-6-(1,1-dimethoxybenzyl)thioxanthone, 2-Methyl-6-(1,1-dimethoxybenzyl)thioxanthone, 2-Methyl-6-morpholinomethylthioxanthone, 2-Methyl-6-morpholinomethylthioxanthone, n-Allylthioxanthone-3,4-dicarboximide, n-Octylthioxanthone-3,4-dicarboximide, N-(1,1,3,3-tetramethylthioxanthone ... methylbutyl)thioxanthone-3,4-dicarboximide, 1-phenoxythioxanthone, 6-ethoxycarbonyl-2-methoxythioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone-2-polyethylene glycol ester, and 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthone-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride.

[0076] The thioxanthone compound may be a commercially available product, such as the SPEEDCURE series manufactured by Lambson (e.g., SPEEDCURE 7010, SPEEDCURE CPTX, SPEEDCURE ITX, etc.).

[0077] From the viewpoint of further reducing odor, the ink of one embodiment of the present disclosure preferably contains, as a polymerization initiator, at least one selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, and more preferably contains phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide.

[0078] From the viewpoint of further reducing odor, the total content of at least one selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide (preferably the total content of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide) is preferably 3.5% by mass or more, more preferably 5% by mass or more, based on the total amount of the ink. The upper limit of the total content is not particularly limited, but is, for example, 10% by mass.

[0079] Furthermore, from the viewpoint of further reducing odor, the ink according to an embodiment of the present disclosure preferably contains, as a polymerization initiator, a compound having two or more thioxanthone skeletons in the molecule.

[0080] The content of the compound having two or more thioxanthone skeletons in the molecule is preferably 1% by mass to 10% by mass, and more preferably 2% by mass to 8% by mass, relative to the total amount of the ink.

[0081] <Polymerization inhibitor> The ink according to one embodiment of the present disclosure preferably contains at least one polymerization inhibitor.

[0082] Examples of the polymerization inhibitor include hydroquinone compounds, phenothiazines, catechols, alkylphenols, alkylbisphenols, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic acid esters, mercaptobenzimidazole, phosphites, nitrosamine compounds, hindered amine compounds, and nitroxyl radicals.

[0083] Among them, the polymerization inhibitor is more preferably a nitrosamine compound.

[0084] Examples of the nitrosamine compound include N-nitroso-N-phenylhydroxylamine aluminum salt and N-nitroso-N-phenylhydroxylamine. Of these, the nitrosamine compound is preferably N-nitroso-N-phenylhydroxylamine aluminum salt.

[0085] The content of the polymerization inhibitor is preferably 0.05% by mass to 1% by mass relative to the total amount of the ink, from the viewpoint of improving the stability over time of the ink.

[0086] <Additives> The ink according to an embodiment of the present disclosure may contain additives such as a co-sensitizer, an ultraviolet absorber, an antioxidant, an anti-fading agent, a conductive salt, a solvent, and a basic compound, as necessary.

[0087] <Physical Properties> The viscosity of the ink is preferably 0.5 mPa·s to 50 mPa·s, more preferably 5 mPa·s to 40 mPa·s, preferably 7 mPa·s to 35 mPa·s, and even more preferably 8 mPa·s to 30 mPa·s. The viscosity is measured at 25°C using a viscometer, for example, a TV-22 viscometer manufactured by Toki Sangyo Co., Ltd.

[0088] The surface tension of the ink is preferably 60 mN / m or less, and more preferably 23 mN / m to 26 mN / m.

[0089] If the surface tension is 23 mN / m to 26 mN / m, when an overcoat layer is provided on an image, it is possible to prevent the overcoat liquid used to form the overcoat layer from repelling onto the image surface. The surface tension is measured at 25° C. using a surface tensiometer, for example, an automatic surface tensiometer manufactured by Kyowa Interface Science Co., Ltd. (product name "CBVP-Z"), by the plate method.

[0090] [Image recording method] An image recording method according to one embodiment of the present disclosure includes a step of applying the ink onto a substrate using an inkjet recording method (hereinafter also referred to as an "ink application step"), and a step of irradiating the applied ink with active energy rays to record an image (hereinafter also referred to as an "active energy ray irradiation step").

[0091] (Step of applying ink using an inkjet recording method) -Base material- The type of the substrate is not particularly limited, and a substrate generally known in the art can be used as the substrate. Examples of the substrate include metal, glass, quartz, and plastic. Examples of the resin constituting the plastic include cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, acrylic resin, chlorinated polyolefin resin, polyethersulfone resin, polyethylene terephthalate (PET), polyethylene naphthalate, nylon, polyethylene, polystyrene, polypropylene, polycycloolefin resin, polyimide resin, polycarbonate resin, and polyvinyl acetal. The plastic may be a film containing only one of these resins, or a film containing two or more of them mixed together.

[0092] The thickness of the substrate is not particularly limited and is, for example, 1 μm to 10 mm.

[0093] Among them, since the ink of the present disclosure has excellent impact resistance and blocking resistance, it is preferable to use metal or plastic as the substrate, and it is more preferable to use metal. After recording an image on a flat metal substrate, a molding process described below is carried out to obtain a metal molded product (e.g., a food can, a beverage can, an aerosol can, etc.). In the image recording method of the present disclosure, an image may be recorded on the substrate after molding.

[0094] -Underlying layer- When a metal is used as the substrate, it is preferable to provide an undercoat layer on the substrate and then apply the ink onto the undercoat layer.

[0095] Examples of the undercoat layer include an anchor coat layer, a base coat layer, a white coat layer, etc. When the undercoat layer is a white coat layer, it is preferable that the white coat layer contains titanium oxide as a pigment.

[0096] The method for forming the underlayer is not particularly limited, and may be, for example, a method of applying an ink for forming the underlayer containing a crosslinkable resin, or a method of laminating a film containing a crosslinkable resin. The thickness of the underlayer is not particularly limited, and may be appropriately adjusted.

[0097] The underlayer preferably contains a crosslinkable resin. The crosslinkable resin may be a thermally crosslinkable resin that crosslinks with heat, or an active energy ray crosslinkable resin that crosslinks with active energy rays.

[0098] Examples of crosslinkable resins include (meth)acrylic resins such as polyacrylonitrile, polymethyl acrylate, and polymethyl methacrylate; polyester resins such as polyethylene terephthalate, isophthalic acid-modified polyethylene terephthalate, and polyethylene naphthalate; epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and cresol novolac epoxy resin; vinyl resins such as polyvinyl acetate and polyvinyl chloride; urethane resins such as diphenylmethane diisocyanate-polyethylene glycol copolymer; and amino resins such as melamine resin, urea resin, and benzoguanamine resin. Only one type of crosslinkable resin may be included, or two or more types may be included.

[0099] The underlayer may further contain resins other than the crosslinkable resin, a crosslinking agent, a crosslinking accelerator, various additives, and the like.

[0100] The method for forming the underlayer can be appropriately selected depending on the crosslinkable resin. When the crosslinkable resin is a thermally crosslinkable resin, it is preferable to apply the ink for forming the undercoat layer to the substrate and then bake the applied ink. The baking temperature is, for example, 140°C to 230°C. The baking time is, for example, 1 minute to 60 minutes.

[0101] When the crosslinkable resin is an active energy ray crosslinkable resin, it is preferable to apply the ink for forming the undercoat layer to the substrate and then irradiate the substrate with active energy rays.

[0102] -Inkjet recording method- The inkjet recording method is not particularly limited as long as it is a method capable of recording an image, and any known method can be used. Examples of inkjet recording methods include a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink to eject ink using radiation pressure, and a thermal inkjet (Bubble Jet (registered trademark)) method that heats ink to form bubbles and uses the resulting pressure.

[0103] Inkjet heads used in inkjet recording methods include a shuttle method, in which a short serial head is used and recording is performed while the head is scanned in the width direction of the substrate, and a line method, in which a line head is used in which recording elements are arranged to correspond to the entire area of ​​one side of the substrate.

[0104] In the line method, a pattern can be formed on the entire surface of the substrate by scanning the substrate in a direction intersecting the arrangement direction of the recording elements, and a transport system such as a carriage for scanning a short head is not required. In addition, the line method does not require complex scanning control of the carriage movement and the substrate, and only the substrate moves, so a higher recording speed can be achieved compared to the shuttle method.

[0105] The amount of ink droplets ejected from the inkjet head is preferably 1 pL (picoliter) to 100 pL, more preferably 3 pL to 80 pL, and even more preferably 3 pL to 50 pL.

[0106] (Active energy ray irradiation process) Examples of active energy rays include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light rays. Among these, the active energy rays are preferably ultraviolet rays.

[0107] The peak wavelength of the ultraviolet light is, for example, preferably 200 nm to 405 nm, more preferably 250 nm to 400 nm, and further preferably 300 nm to 400 nm.

[0108] As a light source for ultraviolet irradiation, various lasers such as mercury lamps, gas lasers, and solid-state lasers are mainly used, and discharge lamps such as mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps are widely known. In addition, semiconductor light sources such as UV-LEDs (ultraviolet light-emitting diodes) and UV-LDs (ultraviolet laser diodes) are small, have a long life, are highly efficient, and are low cost, and are expected to be light sources for ultraviolet irradiation. Among them, the light source for ultraviolet irradiation is preferably a metal halide lamp, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, or a UV-LED.

[0109] In the present disclosure, polymerizing only a portion of the polymerizable monomer in the ink is also referred to as "temporary curing", and irradiation with active energy rays for temporary curing is also referred to as "pinning exposure". In the present disclosure, polymerizing substantially all of the polymerizable compound in the ink is also referred to as "main curing", and irradiation with active energy rays for main curing is also referred to as "main exposure".

[0110] In the actinic energy ray irradiation step, it is preferable to provisionally cure the ink and then fully cure it. Specifically, it is preferable to apply the ink, subject the ink to pinning exposure, and finally subject the ink to full exposure.

[0111] The reaction rate of the ink after pinning exposure is preferably 10% to 80%.

[0112] Here, the reaction rate of the ink means the polymerization rate of the polymerizable compound contained in the ink, which is determined by high performance liquid chromatography.

[0113] By ensuring that the ink reaction rate is 10% or more, insufficient spreading of dots is suppressed, and as a result, the graininess of the final image is improved.

[0114] Furthermore, by keeping the ink reaction rate at 80% or less, interference between ink dots is suppressed, resulting in improved image quality in the final image.

[0115] From the viewpoint of further improving the graininess of the final image, the reaction rate of the ink is preferably 15% or more.

[0116] From the viewpoint of further improving the image quality of the final image obtained, the ink reaction rate is preferably 75% or less, more preferably 50% or less, preferably 40% or less, more preferably 30% or less, and even more preferably 25% or less.

[0117] The reaction rate of the ink after the main exposure is preferably more than 80% and not more than 100%, more preferably from 85% to 100%, and even more preferably from 90% to 100%. When the reaction rate is more than 80%, the adhesion is further improved.

[0118] The reaction rate of the ink is determined by the following method. A substrate is prepared that has been subjected to the operations up to the end of irradiation of the ink with active energy rays. A sample piece (hereinafter referred to as the post-irradiation sample piece) measuring 20 mm x 50 mm is cut out from the region of the substrate where the ink film exists. The cut-out post-irradiation sample piece is immersed in 10 mL of THF (tetrahydrofuran) for 24 hours to obtain an eluate in which the ink has been eluted. The amount of polymerizable compound (hereinafter referred to as the "post-irradiation monomer amount X1") is determined for the obtained eluate by high performance liquid chromatography. Separately, the same operation as above is carried out except that the ink on the substrate is not irradiated with active energy rays, and the amount of polymerizable compound (hereinafter referred to as "monomer amount X1 when not irradiated") is determined. Based on the amount of monomer X1 after irradiation and the amount of monomer X1 before irradiation, the reaction rate (%) of the ink is calculated according to the following formula. Ink reaction rate (%) = ((monomer amount before irradiation X1 - monomer amount after irradiation X1) / monomer amount before irradiation X1) x 100

[0119] The exposure dose of the active energy rays for the pinning exposure is set to 10 mJ / cm from the viewpoint of making it easier to achieve the above-mentioned ink reaction rate. 2 ~100mJ / cm 2 and preferably 20 mJ / cm 2 ~60mJ / cm 2 It is more preferable that:

[0120] The exposure dose of the active energy rays for the main exposure is set to 50 mJ / cm in order to completely cure the ink. 2 ~1000mJ / cm 2 and preferably 200 mJ / cm 2 ~800mJ / cm 2 It is more preferable that:

[0121] In the main exposure, from the viewpoint of improving adhesion to the substrate, it is preferable to irradiate the active energy rays in an atmosphere having an oxygen concentration of less than 1% by volume, more preferably 0.5% by volume or less, and even more preferably 0.3% by volume or less.

[0122] In the active energy ray irradiation step, from the viewpoint of image quality, it is preferable to irradiate the active energy ray within 0.1 to 5 seconds from the time the ink lands. When pinning exposure and main exposure are performed, it is preferable to irradiate the active energy ray for pinning exposure within 0.1 to 5 seconds from the time the ink lands. It is more preferable that the time from the time the ink lands to the irradiation of the active energy ray (when pinning exposure and main exposure are performed, the active energy ray for pinning exposure) is within 0.2 to 1 second.

[0123] (Overcoat layer forming process) The image recording method of the present disclosure preferably further comprises a step of forming an overcoat layer on the recorded image.

[0124] By providing an overcoat layer, damage to the image can be suppressed when molding, which will be described later.

[0125] As the overcoat liquid for forming the overcoat layer, a known transparent coating material can be used. Examples of known transparent coating materials include transparent coating materials containing thermosetting resins such as polyester resins, acrylic resins, and epoxy resins, curing agents such as amino resins, phenolic resins, and isocyanate resins, and lubricants such as paraffin wax, polyethylene wax, and silicone wax.

[0126] The overcoat layer is formed, for example, by applying an overcoat liquid onto the image and then baking it. The baking temperature is, for example, 140°C to 230°C. The baking time is, for example, 1 minute to 60 minutes.

[0127] [Method of manufacturing molded body] A method for producing a molded body according to one embodiment of the present disclosure includes a step of applying the ink onto a substrate using an inkjet recording method (hereinafter also referred to as an "ink application step"); a step of irradiating the applied ink with active energy rays to record an image (hereinafter also referred to as an "active energy ray irradiation step"); and a step of molding the substrate on which the image has been recorded to produce a molded body (hereinafter also referred to as a "molding step").

[0128] The ink application step and the active energy ray irradiation step in the manufacturing method of a molded body according to an embodiment of the present disclosure are the same as the ink application step and the active energy ray irradiation step in the image recording method according to an embodiment of the present disclosure, except for the points described below.

[0129] In the ink application step, the substrate is not particularly limited as long as it is a moldable substrate. The substrate is preferably a metal or plastic, and more preferably a metal.

[0130] (molding process) The molding method is not particularly limited, and examples thereof include bending molding, vacuum molding, extrusion molding, injection molding, compression molding, and blow molding. The shape of the molded body is not particularly limited and may be appropriately determined depending on the application.

[0131] The ink of the present disclosure has excellent blocking resistance. For example, even if an image is recorded on a flat metal substrate and the metal substrates on which the image is recorded are stacked before the molding process, the image is unlikely to peel off. Therefore, the metal substrates on which the image is recorded can be stored before the molding process, and the molding process can be carried out at a desired timing.

[0132] The ink of the present disclosure has excellent impact resistance, and therefore the image is less likely to crack even when a molding process is performed, and therefore a molded product having excellent decorating properties can be obtained. EXAMPLES

[0133] Hereinafter, the present disclosure will be described more specifically with reference to examples. However, the present disclosure is not limited to the following examples as long as it does not depart from the gist of the disclosure.

[0134] <Examples 1 to 14, Comparative Examples 1 to 6> [Preparation of cyan ink] In preparing the cyan ink, first, a cyan pigment dispersion was prepared.

[0135] (Cyan pigment dispersion A) Cyan pigment (30 parts by mass), SOLSPERSE32000 (9 parts by mass) as a dispersant, 3MPDDA (60 parts by mass) as a dispersion medium, and UV22 (1 part by mass) as a polymerization inhibitor were charged into a dispersing machine Motor Mill M50 (manufactured by Eiger), and dispersion treatment was carried out for 4 hours at a peripheral speed of 9 m / s using zirconia beads with a diameter of 0.65 mm, to obtain cyan pigment dispersion A.

[0136] (Cyan pigment dispersion B) Cyan pigment dispersion B was obtained in the same manner as for cyan pigment dispersion A, except that DDDA was used as the dispersion medium instead of 3MPDDA.

[0137] (Cyan pigment dispersion C) Cyan pigment dispersion C was obtained in the same manner as for cyan pigment dispersion A, except that BDDA was used as the dispersion medium instead of 3MPDDA.

[0138] Details of the components contained in the cyan pigment dispersions A to C are as follows.

[0139] Cyan pigment: CI Pigment Blue 15:4 (product name: Heliogen (registered trademark) Blue D 7110 F, manufactured by Sun Chemical (DIC) ) SOLSPERSE32000: Polyethyleneimine-based dispersant (product name: SOLSPERSE32000, manufactured by Lubrizol) 3MPDDA: 3-Methyl-1,5-pentanediol diacrylate (product name "SR341", manufactured by Sartomer) DDDA: 1,10-decanediol diacrylate (product name "SR595", manufactured by Sartomer) BDDA: 1,4-butanediol diacrylate (product name: Viscoat #195, manufactured by Osaka Organic Chemical Industry Co., Ltd.) UV22: A mixture of 2,6-bis(1,1-dimethylethyl)-4-(phenylmethylene)-2,5-cyclohexadiene-1-one and propoxylated glycerin triacrylate (product name: "IRGASTAB UV-22", manufactured by BASF)

[0140] UV22 contains propoxylated glycerin triacrylate as another polymerizable compound. However, since the content of propoxylated glycerin triacrylate is very small, the entire content of UV22 is shown in the "Polymerization inhibitor" column in the table.

[0141] Next, the prepared cyan pigment dispersion was mixed with the components shown in Tables 1 to 3 below so that the content of each component was the content (mass%) shown in Tables 1 to 3. In Examples 1 to 14 and Comparative Examples 3 to 6, cyan pigment dispersion A was used. In Comparative Example 1, cyan pigment dispersion B was used. In Comparative Example 2, cyan pigment dispersion C was used. The mixture was stirred for 20 minutes at 25° C. and 5,000 rpm using a mixer (product name "L4R", manufactured by Silverson) to obtain a cyan ink.

[0142] Details of each component shown in Tables 1 to 3 are as follows. In addition, Speedcure 7010L (manufactured by Lambson) was used to prepare the ink. Speedcure 7010L is a mixture of Speedcure 7010 and EOTMPTA, and the mixing ratio is 1:1 by mass. Speedcure 7010 is a polymerization initiator and EOTMPTA is another polymerizable compound, so they will be explained in the sections on polymerization initiators and other polymerizable compounds, respectively.

[0143] <Specific bifunctional (meth)acrylate> The specific bifunctional (meth)acrylate is a bifunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms. · 3MPDDA: As above. HDDA: 1,6-Hexanediol diacrylate (product name: Viscoat #230, manufactured by Osaka Organic Chemical Industry Co., Ltd.) NDDA: 1,9-Hexanediol diacrylate (product name: Viscoat #260, manufactured by Osaka Organic Chemical Industry Co., Ltd.) PDDA: 1,5-pentanediol diacrylate (product name "QH-0602", Fujifilm Wako Pure Chemical Industries, Ltd.)

[0144] <Benzyl (meth)acrylate> BzA: Benzyl acrylate (product name: Viscoat #160, manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0145] <Other polymerizable compounds> The other polymerizable compounds are polymerizable compounds other than the specific bifunctional (meth)acrylate and benzyl (meth)acrylate. · DDDA: As above. ·BDDA: As above. LA: Lauryl acrylate (product name "LA", manufactured by Osaka Organic Chemical Industry Co., Ltd.) IBOA: Isobornyl acrylate (product name "IBXA", manufactured by Osaka Organic Chemical Industry Co., Ltd.) EOTMPTA: Trimethylolpropane EO-added triacrylate (50% by mass of "Product name: Speedcure 7010L, manufactured by Lambson")

[0146] <Polymerization initiator> BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (product name "Omnirad 819", manufactured by IGM Resins BV) · TPO-L: (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide (product name "Omnirad TPO-L", manufactured by IGM Resins BV) · Speedcure7010: 1,3-di({α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]}oxy)-2,2-bis({α-[1-methylethylene)]}oxymethyl)propane (50% by mass of "product name "Speedcure7010L", manufactured by Lambson")

[0147] <Polymerization inhibitor> UV22: As above.

[0148] <Silicone surfactant> The mass ratio M of the content of the polysiloxane structure to the content of the polyether structure is as follows. TEGORAD2500: (meth)acryloyl group-containing silicone surfactant (product name "TEGORAD2500", manufactured by Evonik, mass ratio M: 0.937369) TEGORAD2200N: (meth)acryloyl group-containing silicone surfactant (product name "TEGORAD2200N", manufactured by Evonik, mass ratio M: 0.36319) TEGORAD2250: (meth)acryloyl group-containing silicone surfactant (product name "TEGORAD2250", manufactured by Evonik, mass ratio M: 0.451587) TEGORAD2300: (meth)acryloyl group-containing silicone surfactant (product name "TEGORAD2300", manufactured by Evonik, mass ratio M: 0.612617)

[0149] <Coloring agent> Cyan pigment: As above.

[0150] <Dispersant> · SOLSPERSE32000: As above.

[0151] [Image recording] -Underlying layer formation process- The base material (tin-free steel plate (product name "Cansuper SR tin-free steel", manufactured by Nippon Steel Corporation)) was coated with an ink for forming a base layer (product name "WA38", acrylic epoxy white base coat, manufactured by DIC Graphics Corporation) at a coating amount of 70 mg / 100 cm. 2 Then, the coating was baked at 190°C for 5 minutes to form a base layer on the substrate.

[0152] -Ink application process, active energy ray irradiation process- Cyan ink was applied twice using an inkjet recording device equipped with an inkjet head (product name "Samba G3L", manufactured by FUJIFILM Dimatix). Specifically, as the first layer, cyan ink was applied to a rectangular area of ​​5 cm x 5 cm on the underlayer at a resolution of 1200 x 1200 dpi (dots per inch) with an ink amount of 6.8 g / m. 2 A 100% solid image was recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 20 mJ / cm. 2The LED light source used was a UV-LED irradiator (product name "G4B", manufactured by Kyocera Corporation) with a peak wavelength of 385 nm. Cyan ink was applied as the second layer on top of the rectangular cyan image of 5 cm x 5 cm in the first layer with a resolution of 1200 x 1200 dpi (dots per inch), and the ink amount was 6.8 g / m. 2 A 100% solid image was recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 800 mJ / cm. 2 The coated film was irradiated with ultraviolet light at 400 rpm to obtain a recorded image.

[0153] - Overcoat layer formation process - Apply 10 g / m of overcoat liquid (product name "GP505W-1 Clear Coating", T&K Toka, containing polyester resin) to the image recording surface of the image recording material. 2 and baked at 190°C for 5 minutes.

[0154] [evaluation] For each of the Examples and Comparative Examples, the obtained image recording matter was used to evaluate impact resistance, blocking resistance, adhesion, overcoat suitability, and image quality.

[0155] The evaluation method is as follows.

[0156] <Impact resistance> A ball weighing 500 g and having a ball radius of 12.7 mm at the impact tip was dropped onto the image recorded material on which the overcoat layer was formed using a DuPont impact tester (Toyo Seiki). The ball was dropped from a height of 10 cm, and the presence or absence of cracks in the image (ink film) on the image recorded surface of the image recorded material was confirmed. If cracks were found in the image, the test was terminated, and if no cracks were found in the image, the ball was dropped from a height of 20 cm and the same test was performed. This test was performed in the order of ball drop heights of 10 cm, 20 cm, 25 cm, and 30 cm. The evaluation criteria are as follows: 5: It didn't break even at a height of 30cm. 4: Cracks occurred at a height of 30 cm 3: A crack occurred at a height of 25 cm. 2: A crack occurred at a height of 20 cm. 1: A crack occurred at a height of 10 cm.

[0157] <Blocking resistance> The image recording surface of the image recording material before the overcoat layer is formed is placed in contact with a tin-free steel plate and subjected to a load of 0.5 ton / m 2 A load of 10 ... 5: No peeling even at 45℃. 4: Peeling occurred at 45°C. 3: Peeling occurred at 30°C. 2: Peeling occurred at 25℃. 1: Peeling occurred at 10℃.

[0158] <Adhesion> A cross-cut test was carried out on the image recording material on which the overcoat layer was formed. The test results were classified according to JIS K5600-5-6 (ISO2409). Classification 0 indicates the best adhesion. The evaluation criteria are as follows: 5: Classification 0. 4: Classification 1. 3: Category 2. 2: Classification 3. 1: Classification 4 or higher.

[0159] <Overcoat suitability> On the image recording surface of the image recording material before forming the overcoat layer, an overcoat liquid (product name "GP505W-1 clear paint", T&K Toka, containing polyester resin) was applied in an amount of 20 g / m 2The test was stopped if cissing occurred, and if no cissing occurred, the application amount of the overcoat liquid was increased to 15 g / m2. 2 The same test was carried out with the overcoat solution applied in an amount of 20 g / m 2 , 15g / m 2 , 10g / m 2 , 5g / m 2 The evaluation criteria were as follows: 5: Application amount 5g / m 2 However, no repelling occurred. 4: Application amount 5g / m 2 Cracks occurred. 3: Coating amount 10g / m 2 Cracks occurred. 2: Coating amount 15g / m 2 Cracks occurred. 1: Coating amount 20g / m 2 Cracks occurred.

[0160] <Image quality> After forming a base layer on the substrate, cyan ink was applied at a resolution of 1200 x 1200 dpi (dots per inch) with an ink amount of 7.4 g / m 2 A 100% solid image was then recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 50 mJ / cm. 2 The image recording surface was observed with a loupe (50x) to check for the presence or absence of gaps. If gaps were present, the test was terminated. If no gaps were present, the ink amount was increased to 7.1 g / m2. 2 The same test was carried out with an ink amount of 7.4 g / m 2 , 7.1g / m 2 , 6.8g / m 2 , 6.5g / m 2 The evaluation criteria were as follows: 5: Ink amount 6.5g / m 2 But there was no gap. 4: Ink amount 6.5g / m 2 And there was a gap. 3: Ink amount 6.8g / m2 And there was a gap. 2: Ink amount 7.1g / m 2 And there was a gap. 1: Ink amount 7.4g / m 2 And there was a gap.

[0161] Tables 1 to 3 show the evaluation results. In Tables 1 to 3, "BzA+M2" means the total content (mass %) of benzyl acrylate and the specific bifunctional (meth)acrylate. "BzA / M2" means the mass ratio of the content of benzyl acrylate to the content of the specific bifunctional (meth)acrylate. "(BzA+M2) / polymerizable compound" means the total content of benzyl acrylate and specific bifunctional (meth)acrylate relative to the total content of all polymerizable compounds (excluding silicone-based surfactants) contained in the ink.

[0162] [Table 1] [Table 2] [Table 3]

[0163] As shown in Tables 1 and 2, in Examples 1 to 14, the ink contained a specific bifunctional (meth)acrylate, benzyl (meth)acrylate, and a colorant, and the total content of the specific bifunctional (meth)acrylate and benzyl (meth)acrylate was 60 mass% or more relative to the total amount of the ink, and it was therefore found that the resulting images had excellent impact resistance and blocking resistance.

[0164] On the other hand, in Comparative Example 1, the ink did not contain the specific bifunctional (meth)acrylate, and it was found that the blocking resistance was poor. In Comparative Example 2, the ink did not contain the specific bifunctional (meth)acrylate, and it was found that the impact resistance was poor. In Comparative Example 3, the ink did not contain benzyl (meth)acrylate, and it was found that the impact resistance was poor. In Comparative Example 4, the total content of the specific bifunctional (meth)acrylate and benzyl (meth)acrylate was less than 60 mass %, and it was found that the impact resistance was poor. In Comparative Example 5, the ink did not contain benzyl (meth)acrylate, and it was found that the blocking resistance was poor. In Comparative Example 6, the total content of the specific bifunctional (meth)acrylate and benzyl (meth)acrylate was less than 60% by mass, and it was found that the blocking resistance was poor.

[0165] In Example 1, the total content of the specific bifunctional (meth)acrylate and benzyl acrylate was 95 mass% or more based on the total amount of the polymerizable compounds, and therefore, it was found that the impact resistance, blocking resistance, and adhesion were excellent compared to Examples 5 and 6 and the comparative example.

[0166] In Example 1, the mass ratio of the content of benzyl acrylate to the content of the specific bifunctional (meth)acrylate was 2 or more, and therefore it was found that Example 1 was superior in impact resistance and adhesion compared to Example 9. In Example 1, the mass ratio of the content of benzyl acrylate to the content of the specific bifunctional (meth)acrylate was 5 or less, and therefore it was found that Example 1 had superior blocking resistance compared to Example 7.

[0167] In Example 9, the content of benzyl acrylate was 50% by mass or more, and therefore it was found that, compared with Example 10, impact resistance and adhesion were superior.

[0168] In Example 11, the surface tension of the ink was 23 mN / m or more, and it was found that the ink had superior overcoat suitability compared to Examples 12 and 13. In Example 1, the surface tension of the ink was 26 mN / m or less, and it was found that the image quality was superior to that of Example 14.

[0169] In Example 11, the silicone-based surfactant contained a polyether structure and a polysiloxane structure, and the mass ratio of the content of the polysiloxane structure to the content of the polyether structure was 0.6 or less. Therefore, it was found that the overcoat suitability was superior to that of Example 12.

[0170] <Example 101> Ink C1 (cyan ink), Ink M1 (magenta ink), Ink Y1 (yellow ink), Ink K1 (black ink), and Ink W1 (white ink) were prepared.

[0171] As ink C1, the cyan ink in Example 1 was used.

[0172] [Preparation of Inks M1, Y1, K1, and W1] First, a magenta pigment dispersion, a yellow pigment dispersion, a black pigment dispersion, and a white pigment dispersion were prepared. The magenta pigment dispersion, the yellow pigment dispersion, the black pigment dispersion, and the white pigment dispersion were prepared by replacing the cyan pigment with the magenta pigment, the yellow pigment, the black pigment, and the white pigment, respectively, in the preparation of the cyan pigment dispersion.

[0173] Details of the magenta pigment, yellow pigment, black pigment, and white pigment are as follows.

[0174] Magenta pigment: CI Pigment RED 122, product name "TRM-33", manufactured by Dainichi Seika Chemicals Co., Ltd. Yellow pigment: CI Pigment Yellow 185, product name "Paliotol Yellow D 1155", manufactured by Sun Chemical (DIC) Black pigment: Carbon black, product name "MOGUL E", manufactured by CABOT White pigment: Titanium oxide, product name "KRONOS 2300", manufactured by KRONOS

[0175] Next, the prepared magenta pigment dispersion, yellow pigment dispersion, black pigment dispersion, and white pigment dispersion were each mixed with the components shown in Table 4 so that the content of each component was the content (mass %) shown in Table 4. The mixture was stirred for 20 minutes at 25°C and 5,000 rpm using a mixer (product name "L4R", manufactured by Silverson) to obtain Inks M1, Y1, K1, and W1.

[0176] [Table 4]

[0177] [Image recording] An underlayer was formed on the substrate in the same manner as in the above underlayer forming step. -2-color multilayer printing- Using an inkjet recording device equipped with an inkjet head (product name "Samba G3L", manufactured by FUJIFILM Dimatix), yellow ink (ink Y1) and magenta ink (ink M1) were each applied once. Specifically, as the first layer, yellow ink was applied to a rectangular area of ​​5 cm x 5 cm on the base layer at a resolution of 1200 x 1200 dpi with an ink amount of 6.8 g / m. 2 A 100% solid image was recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 20 mJ / cm. 2 The LED light source used was a UV-LED irradiator (product name "G4B", manufactured by Kyocera Corporation) with a peak wavelength of 385 nm. Magenta ink was applied as the second layer on top of the 5 cm x 5 cm rectangular yellow image of the first layer at a resolution of 1200 x 1200 dpi, with an ink amount of 6.8 g / m. 2 A 100% solid image was recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 800 mJ / cm. 2 The coated film was irradiated with ultraviolet light at 400 rpm to obtain a recorded image.

[0178] -3-color multilayer printing- Using an inkjet recording device equipped with an inkjet head (product name "Samba G3L", manufactured by FUJIFILM Dimatix), yellow ink (ink Y1), magenta ink (ink M1), and cyan ink (ink C1) were each applied once. In the above two-color multilayer printing, cyan ink was applied as the third layer on top of the 5 cm x 5 cm rectangular magenta image of the second layer at a resolution of 1200 x 1200 dpi, with each ink amount being 4.8 g / m. 2 Except for changing the above, an image recording material was obtained in the same manner as in the above two-color multi-layer printing.

[0179] -4-color multilayer printing- Using an inkjet recording device equipped with an inkjet head (product name "Samba G3L", manufactured by FUJIFILM Dimatix), yellow ink (ink Y1), magenta ink (ink M1), cyan ink (ink C1), and black ink (ink K1) were each applied once. In the above three-color multi-layer printing, black ink was applied as the fourth layer on top of the 5 cm x 5 cm rectangular cyan image of the third layer, at a resolution of 1200 x 1200 dpi, with each ink amount being 3.8 g / m. 2 Except for the above change, an image recording material was obtained in the same manner as in the above three-color multi-layer printing.

[0180] -5-color multilayer printing- Using an inkjet recording device equipped with an inkjet head (product name "Samba G3L", manufactured by FUJIFILM Dimatix), white ink (W1), yellow ink (ink Y1), magenta ink (ink M1), and cyan ink (ink C1) were each applied once. Specifically, as the first layer, white ink was applied to a rectangular area of ​​5 cm x 5 cm on the base layer at a resolution of 1200 x 1200 dpi with an ink amount of 6.8 g / m. 2 A 100% solid image was recorded. After that, an LED light source attached to the inkjet recording device was used to record an image with an exposure of 20 mJ / cm. 2The ink was irradiated with ultraviolet light at 1000 kV. A UV-LED irradiator with a peak wavelength of 385 nm (product name "G4B", manufactured by Kyocera Corporation) was used as the LED light source. An image was recorded in the same manner as in the above four-color multi-layer printing, except that yellow ink was applied on top of the 5 cm x 5 cm rectangular white image of the first layer.

[0181] Using each of the obtained image records, the impact resistance, blocking resistance, adhesion, overcoat suitability, and image quality were evaluated by the same evaluation methods as in Example 1. The evaluation results were all "5".

[0182] Each of the obtained image-recorded products was processed into a square can (depth 15 mm, corner diameter 6 mm) using a press. Each corner of the obtained square can was visually observed to confirm that there were no cracks.

Claims

1. The composition includes a bifunctional (meth)acrylate having a linear or branched alkylene group having 5 to 9 carbon atoms, a benzyl (meth)acrylate, and a colorant, a total content of the bifunctional (meth)acrylate and the benzyl (meth)acrylate is 60 mass % or more based on a total amount of the active energy ray curable inkjet ink.

2. 2 . The active energy ray-curable ink-jet ink according to claim 1 , wherein a total content of the bifunctional (meth)acrylate and the benzyl (meth)acrylate is 95% by mass or more based on a total amount of the polymerizable compounds.

3. 3. The active energy ray-curable ink-jet ink according to claim 1, wherein a mass ratio of a content of the benzyl (meth)acrylate to a content of the bifunctional (meth)acrylate is 2.0 to 5.

0.

4. 3. The actinic energy ray-curable inkjet ink according to claim 1, wherein a content of the benzyl (meth)acrylate is 50% by mass or more based on a total amount of the actinic energy ray-curable inkjet ink.

5. 3. The active energy ray-curable ink-jet ink according to claim 1, which has a surface tension of 23 mN / m to 26 mN / m.

6. The actinic ray-curable ink-jet ink according to claim 1 or 2, further comprising a silicone-based surfactant.

7. The silicone surfactant contains a polyether structure and a polysiloxane structure, The active energy ray-curable ink-jet ink according to claim 6 , wherein a mass ratio of a content of the polysiloxane structure to a content of the polyether structure is 0.6 or less.

8. applying the active energy ray-curable inkjet ink according to claim 1 or 2 onto a substrate by an inkjet recording method; and a step of irradiating the applied actinic energy ray-curable inkjet ink with actinic energy rays to record an image.

9. applying the active energy ray-curable inkjet ink according to claim 1 or 2 onto a substrate by an inkjet recording method; a step of irradiating the applied active energy ray-curable inkjet ink with active energy rays to record an image; and forming the substrate having the image recorded thereon to form a molded article.

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