Image recording method, method for manufacturing laminate, and image recording apparatus

Abstract

Provided are: an image recording method which includes a step for applying, by an inkjet recording system, an active energy ray-curable ink onto a base material for image recording containing a polymer that contains vinyl chloride as a constituent unit, and a step for recording an image by irradiating the applied active energy ray-curable ink with an active energy ray, wherein the maximum illuminance of the active energy ray is 9.0 W / cm2 or less, the irradiation time is 0.075 sec or more, and the integrated exposure quantity is 0.3 J / cm2 to 3.0 J / 2; and applications of the image recording method.

Description

Image recording method, method for manufacturing a laminate body, and image recording apparatus

[0001] This disclosure relates to an image recording method, a method for manufacturing a laminate, and an image recording apparatus.

[0002] Conventionally, technologies for recording images on resin substrates using inkjet inks have been proposed. As one example, a technology is known in which an image is recorded using inkjet ink, and then another substrate is laminated onto the image to produce a laminated body, and various studies have been conducted on this technology.

[0003] As an example of image recording technology, a technology is known for recording images on a substrate using a polymer containing vinyl chloride as a constituent unit. For example, Japanese Patent Publication No. 2016-112701 describes an inkjet recording method for recording an image on a substrate by ejecting and curing an active light-curable ink onto a substrate using an inkjet method, the method comprising an image forming step of attaching an active light-curable color ink and an active light-curable white ink to the first surface of a substrate having a first surface and a second surface and a transmittance of 80% or more for light with a wavelength of 350 to 400 nm, such that the color ink is positioned closer to the substrate than the white ink, and after the image forming step, from the first surface side onto the substrate The process includes a first exposure step of irradiating a color ink and a white ink with active light, and a second exposure step after the first exposure step of irradiating the color ink and the white ink on the substrate with active light containing light with a wavelength of 350 to 400 nm by transmitting the light through the substrate from a second side. The color ink contains a colorant other than titanium dioxide, a radical polymerizable compound, a radical photopolymerization initiator, and a gelling agent, and the white ink contains titanium dioxide, a radical polymerizable compound, a radical photopolymerization initiator, and a gelling agent. The integrated light dose in the first irradiation step is 500 mJ / cm². ２The following inkjet recording method is described. International Publication No. 2020 / 044475 describes a method for manufacturing a printed material, comprising: a printing step of forming a printed layer on a non-absorbent or slightly absorbent substrate by an inkjet recording method using an active light-curable ink; a first active light irradiation step of irradiating the printed layer with active light to set the polymerization rate of the photopolymerizable compound of the ink constituting the printed layer to a range of 5% to 80%; a laminating step of laminating a laminate film onto the printed layer via an adhesive layer; and a second active light irradiation step of irradiating the printed layer with active light from the laminate film side or the non-absorbent or slightly absorbent substrate side to further increase the polymerization rate of the photopolymerizable compound of the ink constituting the printed layer. Japanese Patent Publication No. 2022-127859 describes a method for manufacturing a recording, comprising: a first ejection step of ejecting a first ink, which is a radiation-curable inkjet composition, and adhering it to a recording medium; a first irradiation step of irradiating the first ink adhering to the recording medium with radiation to obtain a cured coating film of the first ink; a second ejection step of ejecting a second ink, which is a radiation-curable inkjet composition, and adhering it to the cured coating film of the first ink such that the duty cycle is 1% or more and 20% or less; a second irradiation step of irradiating the second ink adhering to the recording medium with radiation to cure the second ink and obtain a recording; and a stacking step of stacking the recordings so that the recording surface on which the first and second inks are adhering faces the non-recording surface on which the first and second inks are not adhering. Japanese Patent Publication No. 2022-126460 describes an image forming method comprising: a first dispensing step of dispensing a first active energy ray-curable composition (1) containing a (meth)acrylamide compound (A) having a (meth)acrylic group and a polymerization initiator (C) onto a medium; an irradiation step of irradiating the first active energy ray-curable composition (1) dispensed onto the medium with active energy rays; and a second dispensing step of dispensing an ink (2) containing a colorant, a water-soluble organic solvent, and water onto the first active energy ray-curable composition (1) that has been irradiated with active energy rays.

[0004] Furthermore, a technique is also known in which an image is recorded on an image recording base material containing a polymer containing vinyl chloride as a constituent unit, and a laminate base material containing a polymer containing vinyl chloride as a constituent unit is laminated on the obtained image to obtain a laminate body.

[0005] When producing a laminate body as in the above technique, in practical use, it is required that the laminate strength of the obtained laminate body (that is, the peel strength between the image recording base material and the image, and the peel strength between the laminate base material and the image) is good. When a polymer containing vinyl chloride as a constituent unit is used in the production of a laminate body, improvement of its strength has been an issue.

[0006] The present disclosure has been made in view of such circumstances, and the problem to be solved by one embodiment of the present disclosure is to provide an image recording method, a method for producing a laminate body, and an image recording apparatus that are excellent in the adhesion of an image (particularly, the laminate strength when producing a laminate body) when using a base material containing a polymer containing vinyl chloride as a constituent unit.

[0007] The present disclosure includes the following aspects. <1> A step of applying an active energy ray-curable ink by an inkjet recording method on an image recording base material containing a polymer containing vinyl chloride as a constituent unit, and a step of irradiating the applied active energy ray-curable ink with active energy rays to record an image, wherein the maximum illuminance of the active energy rays is 9.0 W / cm ２ or less, the irradiation time is 0.075 seconds or more, and the integrated exposure amount is 0.3 J / cm ２ to 3.0 J / cm ２ An image recording method. <2> The image recording method according to <1>, wherein the maximum illuminance of the active energy rays is 2 W / cm ２ to 7 W / cm ２ ２ ２ to 2.0 J / cm ２ ２ ２An image recording method described in any one of <1> to <3>, less than <5>. <5> In the image recording step, the active energy rays are irradiated two or more times, and the illuminance of the active energy rays is 2 W / cm² each time. ２ ~8W / cm ２ The image recording method according to any one of <1> to <4>, wherein the irradiance of the active energy ray is increased in steps with each irradiation. <6> The image recording method according to any one of <1> to <5>, wherein the image recording substrate has a glass transition temperature of 25°C or higher. <7> The image recording method according to any one of <1> to <6>, wherein the image recording substrate has a thickness of 50 μm or more. <8> The image recording method according to any one of <1> to <7>, further comprising a step of cooling the image recording substrate before the step of recording an image. <9> The image recording method according to any one of <1> to <8>, wherein the surface temperature of the image recording substrate at the time when irradiation with the active energy ray is completed is 10°C to 35°C. <10> An image recording method according to any one of <1> to <9>, wherein the active energy ray curable ink contains polymerizable monomers, the proportion of monofunctional polymerizable monomers in the polymerizable monomers is 80% by mass or more, and the proportion of polymerizable monomers with a molecular weight of 205 or less in the polymerizable monomers is 80% by mass or more. <11> A method for producing a laminate, comprising the steps of: recording an image on an image recording substrate using the image recording method according to any one of <1> to <10>; and laminating a laminate substrate containing a polymer with vinyl chloride as a constituent unit onto the surface of the image. <12> An inkjet head used in the image recording method according to any one of <1> to <10>, comprising an inkjet head for applying active energy ray curable ink to an image recording substrate, and a light source for irradiating with active energy rays, wherein the maximum illuminance of the active energy rays is 9.0 W / cm². ２ Adjust the settings as follows, adjusting the irradiation time to 0.075 seconds or longer, and the integrated exposure dose to 0.3 J / cm². ２ ~3.0 J / cm ２An image recording apparatus that records an image by adjusting to <13> A cooling unit that cools a base material for image recording before the light source irradiates active energy rays, and a detection unit that detects the surface temperature of the base material for image recording when the irradiation of the active energy rays ends, The cooling unit adjusts the cooling intensity based on the value of the surface temperature obtained by the detection unit. The image recording apparatus according to <12>.

[0008] According to an embodiment of the present disclosure, there are provided an image recording method, a method for manufacturing a laminate, and an image recording apparatus that are excellent in the adhesion of an image (particularly, the laminate strength when a laminate is manufactured) when using a base material containing a polymer containing vinyl chloride as a constituent unit.

[0009] FIG. 1 conceptually shows an example of an image recording apparatus used for implementing the image recording method of the present disclosure.

[0010] In this specification, the numerical range indicated by "~" means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another stepwise numerical range. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples. In this specification, the amount of each component in the composition means the total amount of the plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved.

[0011] In this specification, "image" means all films formed by applying ink, and "image recording" means forming an image (i.e., a film). Also, the concept of "image" in this specification includes solid images. In this specification, "(meth)acryloyl group" is a concept that includes both acryloyl group and methacryloyl group, "(meth)acrylate" is a concept that includes both acrylate and methacrylate, and "(meth)acrylic" is a concept that includes both acrylic and methacrylic.

[0012] [Image Recording Method] The image recording method of the present disclosure includes a step of applying an active energy ray curable ink (hereinafter also simply referred to as "ink") by an inkjet recording method onto an image recording substrate containing a polymer having vinyl chloride as a constituent unit, and a step of irradiating the applied ink with active energy rays to record an image, and the maximum illuminance of the active energy rays is 9.0 W / cm ２ or less, the irradiation time is 0.075 seconds or more, and the integrated exposure amount is 0.3 J / cm ２ to 3.0 J / cm ２ or less.

[0013] According to the image recording method of the present disclosure, when an image is recorded on an image recording substrate containing a polymer having vinyl chloride as a constituent unit, the adhesion between the substrate and the image is excellent. And when an image is recorded on an image recording substrate containing a polymer having vinyl chloride as a constituent unit, and a laminate substrate containing a polymer having vinyl chloride as a constituent unit is laminated on the obtained image to obtain a laminate, the laminate strength of the obtained laminate (i.e., the peel strength between the image recording substrate and the image, and the peel strength between the laminate substrate and the image) is excellent.

[0014] The inventors have found that by controlling the maximum illuminance of the active energy rays, the irradiation time, and the cumulative exposure amount within the above range, the adhesion of images is improved when using a substrate containing a polymer with vinyl chloride as a constituent unit, and for example, the laminate strength is improved when a laminate is manufactured. The reason for this effect is presumed to be as follows. In the image recording method of the present disclosure, the illuminance of the active energy rays is relatively lower than in conventional image recording methods, the irradiation time is relatively longer, and the cumulative exposure amount is controlled within a predetermined range. With such control, the ink film formed by the ink irradiated onto the image recording substrate has increased strength and excellent flexibility. The ink film becomes less susceptible to damage from heat and / or pressure during lamination, the adhesion to the substrate is improved, and the laminate strength of the laminate is also improved.

[0015] The image recording method described in this disclosure will be explained in more detail below.

[0016] <Ink Application Process> The image recording method of the present disclosure includes a step of applying ink to an image recording substrate containing a polymer with vinyl chloride as a constituent unit, using an inkjet recording method (hereinafter also referred to as the "ink application process").

[0017] (Image recording substrate) In the ink application process, ink is applied to the image recording substrate. This results in an image recording object that includes the image recording substrate and an image recorded on the image recording substrate.

[0018] The image recording substrate contains a polymer that includes vinyl chloride as a constituent unit.

[0019] A polymer containing vinyl chloride as a constituent unit may be a homopolymer of vinyl chloride (i.e., polyvinyl chloride), or it may be a copolymer containing vinyl chloride and other monomers other than vinyl chloride as constituent units.

[0020] Examples of copolymers containing vinyl chloride and other monomers other than vinyl chloride as constituent units include vinyl chloride-urethane copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, and vinyl chloride-ethylene-vinyl acetate copolymer.

[0021] In particular, the image recording substrate preferably contains polyvinyl chloride.

[0022] The image recording substrate may contain components other than polymers containing vinyl chloride as a constituent unit. Examples of other components include plasticizers, stabilizers, antioxidants, ultraviolet absorbers, binder resins, and colorants.

[0023] In particular, the image recording substrate is preferably opaque in its surface from the viewpoint of improving the color development of the image recording layer. Specifically, it is preferable that there is a region on the surface of the image recording substrate in which the transmittance to light with a wavelength of 400 nm to 700 nm is less than 70%.

[0024] The image recording substrate may have a layer containing a polymer with vinyl chloride as a constituent unit and a surface treatment layer, but from the viewpoint of obtaining adhesion between the image recording substrate and the image by dissolving the ink in the image recording substrate, it is preferable that the surface treatment layer is omitted. In other words, it is preferable that the surface of the image recording substrate to which the ink is applied contains a polymer with vinyl chloride as a constituent unit.

[0025] The glass transition temperature of the image recording substrate is preferably 25°C or higher, and more preferably 30°C or higher, from the viewpoint of suppressing deformation of the image recording substrate. The upper limit of the glass transition temperature is, for example, 100°C.

[0026] In this disclosure, the glass transition temperature of the image recording substrate is measured using a differential scanning calorimeter (product name "DSC7000X", manufactured by Hitachi High-Tech Science Corporation).

[0027] The thickness of the image recording substrate is not particularly limited, but from the viewpoint of suppressing deformation of the image recording substrate, it is preferably 50 μm or more, and more preferably 60 μm or more. The upper limit of the thickness is, for example, 1000 μm.

[0028] In this disclosure, the thickness of the image recording substrate is measured using a digital indicator (model number "ID-C112XBS", manufactured by Mitutoyo Corporation).

[0029] (Ink) The ink applied in the ink application process is an active energy ray curable ink. An active energy ray curable ink is an ink that hardens when irradiated with active energy rays. Examples of active energy rays include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light. Among these, ultraviolet rays are preferred as the active energy ray. The active energy ray curable ink is preferably an ultraviolet-curable ink.

[0030] -Polymerizable Compounds- The ink preferably contains at least one polymerizable compound in order to cure by irradiation with active energy rays.

[0031] In this disclosure, "polymerizable compound" means a compound having a polymerizable group. Preferably, the polymerizable group is an ethylenically unsaturated group (i.e., a group containing an ethylenically double bond), and more preferably, a (meth)acryloyl group, an allyl group, a styryl group, or a vinyl group.

[0032] A polymerizable compound preferably contains at least one polymerizable monomer. Here, a polymerizable monomer refers to a polymerizable compound with a molecular weight of 1000 or less. Here, the molecular weight is calculated based on the types and number of atoms that make up the compound. Hereinafter, polymerizable monomers may be simply abbreviated as "monomers".

[0033] The polymerizable compound may contain polymerizable compounds with a molecular weight exceeding 1000, but it is preferable that it contains polymerizable monomers as the main component. More specifically, the proportion of polymerizable monomers in the polymerizable compound in the ink is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The proportion of polymerizable monomers may also be 100% by mass.

[0034] The polymerizable monomer may be a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer. Here, a monofunctional polymerizable monomer means a polymerizable monomer having only one polymerizable group, and a polyfunctional polymerizable monomer means a polymerizable monomer having two or more polymerizable groups. That is, an n-functional monomer in this disclosure is a polymerizable monomer having n polymerizable groups.

[0035] Examples of monofunctional polymerizable monomers 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, benzyl (meth)acrylate, butoxymethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-(2-methoxy Ethoxyethyl (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, Lysidyloxybutyl (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 trimethylolpropaneformal mono(meth)acrylate,Phenylglycidyl 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 succinic acid, 2-methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, ethoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol Examples include (meth)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, 2-(meth)acryloyloxyethyl succinate, and γ-butyl lactone acrylate.

[0037] Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-n-butyl(meth)acrylamide, N-t-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)acryloylmorpholin.

[0038] Examples of monofunctional aromatic vinyl compounds include styrene, dimethylstyrene, trimethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, methyl vinylbenzoate, 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, 4-t-butoxycarbonylstyrene, 4-t-butoxystyrene, and 5-methyl-3-vinyloxazolidine-2-one.

[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] Examples of polyfunctional polymerizable monomers include polyfunctional (meth)acrylates 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, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, heptanediol di(meth)acrylate, and EO-modified neopentyl glycol di(meth)acrylate. Crylate, PO-modified neopentyl glycol di(meth)acrylate, EO-modified hexanediol di(meth)acrylate, PO-modified hexanediol di(meth)acrylate, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, 9,Examples include 9-bis[4-(2-hydroxyethoxy)phenyl]ful orange (meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane EO-added tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, and tris(2-acryloyloxyethyl) isocyanurate.

[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. Examples include trivinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexanyl ether, EO-added trimethylolpropane trivinyl ether, PO-added trimethylolpropane trivinyl ether, EO-added ditrimethylolpropane tetravinyl ether, PO-added ditrimethylolpropane tetravinyl ether, EO-added pentaerythritol tetravinyl ether, PO-added pentaerythritol tetravinyl ether, EO-added dipentaerythritol hexanyl ether, and PO-added dipentaerythritol hexanyl ether.

[0044] From the viewpoint of further improving the laminate strength, the proportion of monofunctional polymerizable monomers in the polymerizable monomer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. The proportion of monofunctional polymerizable monomers in the polymerizable monomer may be 100% by mass.

[0045] The proportion of polymerizable monomers with a molecular weight of 205 or less in the total polymerizable monomer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. The proportion of polymerizable monomers with a molecular weight of 205 or less in the total polymerizable monomer may be 100% by mass.

[0046] A molecular weight of 205 or less for polymerizable monomers indicates a relatively low molecular weight. A molecular weight of 205 or less makes the ink more easily soluble in the image recording substrate. As a result, the adhesion between the image recording substrate and the ink film improves, and the lamination strength is enhanced. Furthermore, a molecular weight of 205 or less for polymerizable monomers shortens the distance between crosslinking points, increasing the density of the ink film and thus improving the lamination strength.

[0047] The lower limit of the molecular weight of polymerizable monomers with a molecular weight of 205 or less is not particularly limited, but for example, it is 100. The molecular weight is calculated based on the types and number of atoms that make up the compound.

[0048] Examples of polymerizable monomers with a molecular weight of 205 or less include the following compounds: Tetrahydrofurfuryl acrylate (molecular weight: 156) Cyclic trimethylolpropane formal monoacrylate (molecular weight: 200) Ethoxydiethylene glycol acrylate (molecular weight: 188) Cyclohexyl acrylate (molecular weight: 154) Phenoxyethyl acrylate (molecular weight: 192) 4-Hydroxybutyl acrylate (molecular weight: 144) γ-Butyl lactone acrylate (molecular weight: 156) Benzyl acrylate (molecular weight: 162) N-Vinyl-ε-Caprolactam (molecular weight: 139) 5-Methyl-3-vinyloxazolidine-2-one (molecular weight: 127) 4-Acryloylmorpholine (molecular weight: 141)

[0049] From the viewpoint of improving the curability of the ink, the content of polymerizable compounds is preferably 70% to 98% by mass, and more preferably 80% to 95% by mass, relative to the total amount of ink.

[0050] -Colorants- The ink preferably contains at least one colorant. There are no particular restrictions on the colorant, and any known colorants such as pigments, water-soluble dyes, and disperse dyes can be arbitrarily selected and used. Among these, pigments are preferred as colorants because they have excellent weather resistance and rich color reproduction.

[0051] The type of pigment is not particularly limited and may be either an organic pigment or an inorganic pigment. Examples of pigments include those described in "Dictionary of Pigments" edited by Seijiro Ito (published in 2000), "Industrial Organic Pigments" by W. Herbst and K. Hunger, Japanese Patent Publication No. 2002-12607, Japanese Patent Publication No. 2002-188025, Japanese Patent Publication No. 2003-26978, and Japanese Patent Publication No. 2003-342503.

[0052] If the ink contains pigments as colorants, it may also contain pigment dispersants as needed.

[0053] Regarding colorants such as pigments and pigment dispersants, prior art documents such as paragraphs 0152 to 0158 of Japanese Patent Publication No. 2011-225848 and paragraphs 0132 to 0149 of Japanese Patent Publication No. 2009-209352 can be appropriately referred to.

[0054] If the ink contains a colorant, the colorant content is preferably 0.1% to 20% by mass, and more preferably 0.5% to 10% by mass, relative to the total amount of ink.

[0055] -Other Components- The ink may contain other components not listed above. Examples of other components include photopolymerization initiators, polymerization inhibitors, sensitizers, resins, ultraviolet absorbers, antioxidants, fade inhibitors, conductive salts, etc. For other components, publicly available documents such as Japanese Patent Publication No. 2011-225848 and Japanese Patent Publication No. 2009-209352 can be appropriately referred to.

[0056] - Physical properties of the ink - From the viewpoint of ejection performance, the viscosity of the ink is preferably 4 mPa·s to 50 mPa·s, more preferably 4 mPa·s to 30 mPa·s, and even more preferably 4 mPa·s to 15 mPa·s.

[0057] Viscosity refers to the value measured at 25°C. Viscosity is measured using a viscometer, for example, a VISCOMETER RE-85L (manufactured by Toki Sangyo Co., Ltd.).

[0058] From the viewpoint of ejection performance, the surface tension of the ink is preferably 60 mN / m or less, more preferably 20 mN / m to 50 mN / m, and even more preferably 25 mN / m to 45 mN / m.

[0059] Surface tension refers to the value measured at 25°C. Surface tension is measured using a surface tension meter, for example, the "Automatic Surface Tensionometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.)".

[0060] (Ink application) In the ink application process, the above-mentioned ink is applied to the image recording substrate using an inkjet recording method.

[0061] There are no particular restrictions on the ink ejection method in an inkjet recording system, and any known method may be used, such as a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that utilizes the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electrical signal into an acoustic beam and irradiates the ink to eject ink using the radiation pressure, and a thermal inkjet (bubble jet®) method that heats the ink to form bubbles and utilizes the resulting pressure.

[0062] As an inkjet recording method, the method described in Japanese Patent Publication No. 54-59936 is particularly effective, as it involves the ink undergoing a rapid volume change due to the action of thermal energy, and the force resulting from this state change ejects the ink from the nozzle. As an inkjet recording method, the method described in paragraphs 0093 to 0105 of Japanese Patent Publication No. 2003-306623 can also be applied.

[0063] Ink is applied to the image recording substrate using an inkjet recording method by ejecting ink from the nozzles of the inkjet head.

[0064] Inkjet head systems include the shuttle system, which uses a short serial head to scan the recording medium in the width direction while recording, and the line system, which uses a line head in which recording elements are arranged to cover the entire width of one side of the recording medium.

[0065] In the line method, image recording can be performed across the entire surface of the recording medium by scanning it in a direction intersecting the arrangement direction of the recording elements. The line method eliminates the need for a transport system such as a carriage that scans the short head, which is required in the shuttle method. Furthermore, compared to the shuttle method, the line method eliminates the need for complex scanning control of the carriage movement and the recording medium, as only the recording medium moves. For this reason, the line method enables faster image recording compared to the shuttle method.

[0066] Ink application is preferably carried out using an inkjet head having a resolution of 300 dpi or higher (more preferably 600 dpi or higher, and even more preferably 800 dpi or higher). Here, dpi is an abbreviation for dots per inch, and 1 inch is equal to 2.54 cm.

[0067] From the viewpoint of obtaining a high-definition image, the amount of ink droplets ejected from the nozzle of the inkjet head is preferably 1 pL (picoliters) to 10 pL, and more preferably 1.5 pL to 6 pL.

[0068] <Activated Energy Ray Irradiation Step> The image recording method of the present disclosure includes a step of irradiating an applied ink with activated energy rays to record an image (hereinafter also referred to as the "activated energy ray irradiation step").

[0069] By irradiating ink applied to an image recording substrate with active energy rays, polymerization reactions of polymerizable compounds contained in the ink proceed. This allows for image fixation and improvement of image hardness and other properties.

[0070] Examples of active energy rays include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light.

[0071] The irradiation conditions and basic irradiation method for the active energy rays can be those disclosed in Japanese Patent Publication No. 60-132767. Specifically, the irradiation method is preferably one in which light sources are provided on both sides of the head unit including the ink ejection device, and the head unit and light sources are scanned in a so-called shuttle manner, or one in which irradiation is performed by a separate light source that does not involve driving.

[0072] Discharge lamps and laser light sources (gas lasers and solid-state lasers, etc.) are the main light sources used. Examples of discharge lamps include mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps. Semiconductor light sources such as UV-LEDs (light-emitting diodes) and UV-LDs (laser diodes) are small, have a long lifespan, are highly efficient, and are low-cost, making them promising light sources for ultraviolet irradiation. Among these, metal halide lamps, high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, or UV-LEDs are preferred as light sources for ultraviolet irradiation.

[0073] In the image recording method disclosed herein, the maximum illuminance of the active energy rays is 9.0 W / cm². ２ The following conditions must be met: the irradiation time is 0.075 seconds or longer, and the cumulative exposure is 0.3 J / cm². ２ ~3.0 J / cm ２ The cumulative exposure is 0.3 J / cm². ２ ~3.0 J / cm ２ Within this range, the maximum illuminance is set to 9.0 W / cm². ２ By setting the irradiation time to 0.075 seconds or longer, adhesion to substrates containing polymers with polyvinyl chloride as a constituent unit is improved, and the laminate strength when formed into a laminate is also excellent.

[0074] The number of times the active energy rays are irradiated may be only once or multiple times. From the viewpoint of increasing the laminate strength, the number of times the active energy rays are irradiated is preferably 2 to 6 times, and more preferably 3 to 5 times. When the active energy rays are irradiated multiple times, the illuminance of the active energy rays in each irradiation may be the same or different. When the active energy rays are irradiated multiple times, the maximum illuminance refers to the highest illuminance of the active energy rays in each irradiation.

[0075] From the perspective of improving laminate strength, the maximum illuminance of the active energy rays is 9.0 W / cm². ２ The following is true: 8 W / cm ２ Preferably, it is 7 W / cm² ２The following is more preferable: From the viewpoint of improving laminate strength, the maximum illuminance of the active energy rays should be 2 W / cm². ２ Preferably, it is 3 W / cm² or higher. ２ It is more preferable that the above conditions are met. That is, the maximum illuminance of the active energy rays is 2 W / cm². ２ ~7W / cm ２ Preferably, it is 3 W / cm ２ ~7W / cm ２ It is preferable that it be so.

[0076] When irradiating with active energy rays multiple times, the irradiation time for each irradiation may be the same or different. When irradiating with active energy rays multiple times, the irradiation time refers to the total time during which the active energy rays were irradiated.

[0077] The irradiation time is 0.075 seconds or longer, preferably 0.09 seconds or longer, and more preferably 0.1 seconds or longer. The upper limit of the irradiation time is, for example, 1 second.

[0078] Total exposure is the product of illuminance and exposure time.

[0079] When irradiating with active energy rays multiple times, the exposure dose for each irradiation may be the same or different. When irradiating with active energy rays multiple times, the cumulative exposure dose refers to the sum of the exposure doses for each irradiation.

[0080] The cumulative exposure is 0.3 J / cm². ２ ~3.0 J / cm ２ Therefore, 0.4 J / cm ２ ~2.0 J / cm ２ It is preferable that the cumulative exposure amount is 3.0 J / cm². ２ The following conditions improve the lamination strength. Also, the cumulative exposure dose is 0.3 J / cm². ２ This improves the lamination strength.

[0081] From the viewpoint of suppressing deformation of the image recording substrate, the active energy beam is irradiated two or more times, with an exposure dose of 0.6 J / cm² per irradiation. ２ Preferably less than 0.3 J / cm² ２The following is more preferable: The lower limit of the exposure per exposure is, for example, 0.1 J / cm². ２ That is the case.

[0082] From the viewpoint of further suppressing deformation of the image recording substrate, the illuminance of the active energy rays is set to 2 W / cm² in all cases. ２ ~8W / cm ２ Therefore, it is preferable to gradually increase the illuminance of the active energy rays with each irradiation. Gradually increasing the illuminance of the active energy rays mitigates the curing shrinkage of the ink. As a result, deformation of the image recording substrate is thought to be suppressed. For example, when irradiating with active energy rays four times, it is preferable that the illuminance of the second irradiation is higher than that of the first irradiation, the illuminance of the third irradiation is higher than that of the second irradiation, and the illuminance of the fourth irradiation is higher than that of the third irradiation.

[0083] <Cooling Step> The image recording method of the present disclosure preferably includes a step of cooling the image recording substrate (hereinafter also referred to as the "cooling step").

[0084] In general image recording, the image recording substrate is often preheated to accelerate curing. In contrast, the image recording method of this disclosure differs from conventional methods in that the image recording substrate is cooled.

[0085] The method for cooling the image recording substrate is not particularly limited. Examples include contacting a cooling member with the side of the image recording substrate opposite to the side to which the ink is applied; or blowing air onto the image recording substrate from the image recording surface, the side opposite to the image recording surface, or both.

[0086] The timing for cooling the image recording substrate may be before the active energy ray irradiation process, or during the active energy ray irradiation process. The timing for cooling the image recording substrate may be before the ink application process, during the ink application process, or after the ink application process.

[0087] Normally, the surface temperature of the image recording substrate tends to rise after the active energy ray irradiation process. By performing a cooling process, the rise in surface temperature of the image recording substrate after irradiation with active energy rays is suppressed. Therefore, deformation of the image recording substrate is suppressed.

[0088] The surface temperature of the image recording substrate at the time of completion of irradiation with active energy rays is preferably 10°C to 35°C, and more preferably 20°C to 30°C. In this disclosure, the surface temperature of the image recording substrate is measured using a radiation thermometer (infrared radiation thermometer with laser marker "AD-5619", manufactured by AND Corporation).

[0089] [Method for manufacturing a laminated body] The method for manufacturing a laminated body according to the present disclosure includes the steps of recording an image on an image recording substrate using the image recording method described above, and directly laminating a laminate substrate containing a polymer with vinyl chloride as a constituent unit onto the image (hereinafter also referred to as the "laminating step").

[0090] The details of the process for recording an image on an image recording substrate using an image recording method are as described above.

[0091] (Laminating Substrate) The laminating substrate contains a polymer that includes vinyl chloride as a constituent unit. The preferred embodiment of the laminating substrate is the same as the preferred embodiment of the image recording substrate.

[0092] (Laminating Method) In the laminating process, the laminating substrate is directly laminated (i.e., heat-pressed) onto the image recorded on the image recording substrate in the image recording method. That is, in the laminating process, the image recording object, which includes the image recording substrate and the image, and the laminating substrate are laminated together with the image and the laminating substrate in contact. This results in a laminated body having a layered structure of laminating substrate / image / image recording substrate.

[0093] From the viewpoint of suppressing thermal decomposition, the upper limit of the lamination temperature (i.e., the heat-sealing temperature) is preferably 200°C, more preferably 160°C, and even more preferably 140°C.

[0094] Note that the heat-pressing temperature refers to the surface temperature of the substrate used for lamination.

[0095] The lamination pressure (i.e., the heat-sealing pressure) is preferably 0.1 MPa to 20 MPa, and more preferably 0.5 MPa to 15 MPa.

[0096] The lamination time (i.e., heat sealing time) is, for example, between 10 and 500 seconds.

[0097] The laminate obtained by the manufacturing method of the laminate according to this disclosure can be used, for example, as flooring or walling material for transportation equipment (railways, buses, etc.) or as flooring or walling material for buildings.

[0098] [Image Recording Device] The image recording device of this disclosure is used in the above-described image recording method and comprises an inkjet head for applying ink to an image recording substrate and a light source for irradiating with active energy rays, wherein the maximum illuminance of the active energy rays is 9.0 W / cm². ２ Adjust the settings as follows, adjusting the irradiation time to 0.075 seconds or longer, and the integrated exposure dose to 0.3 J / cm². ２ ~3.0 J / cm ２ The image is recorded by adjusting the settings accordingly. The above image recording device achieves the same effects as the image recording method of this disclosure described above.

[0099] <Example of an Image Recording Device> Figure 1 is a conceptual diagram showing an example of an image recording device used in the image recording method of the present disclosure. The inkjet recording device 100 shown in Figure 1 is an example of an image recording device equipped with a transport mechanism that transports an image recording substrate A1 in a roll-to-roll manner. The inkjet recording device 100 unwinds a long film-shaped image recording substrate A1 that is wound into a roll using an unwinding device R1, transports the unwinded image recording substrate A1 in the direction of the block arrow while tension P is applied, passes it through an inkjet head IJ, light source L1, light source L2, light source L3, and light source L4 in that order, and finally winds it up using a winding device R2 that includes a winding core while tension P is applied.

[0100] The image recording substrate A1 is transported under tension P and wound up under tension P. The tension during transport may be the same as or different from the tension P during winding. Furthermore, the tension may differ depending on the position in the transport direction, or it may be uniform. The inkjet recording device 100 may be equipped with tension adjustment means for adjusting the tension P. Examples of tension adjustment means include powder brakes provided on the unwinding device R1 and / or winding device R2, dancer rolls provided in the middle of the transport path, and control devices (e.g., tension controllers) that control each tension by adjusting various conditions of the inkjet recording device. The inkjet recording device 100 may also be equipped with tension measuring means (e.g., tension meter) for measuring the tension P.

[0101] Note that Figure 1 is a conceptual diagram, and therefore the transport path of the image recording substrate A1 is simplified and shown as if the image recording substrate A1 is transported in one direction. However, it goes without saying that in reality, the transport path of the image recording substrate A1 may meander. Various web transport methods such as cylinders and rolls can be appropriately selected as the transport method for the image recording substrate A1.

[0102] With respect to the unwinding device R1 for unwinding the image recording substrate A1, the following components are arranged downstream of the image recording substrate A1 in the transport direction: an inkjet head IJ, a light source L1, a light source L2, a light source L3, and a light source L4, in that order from upstream of the image recording substrate A1 in the transport direction.

[0103] Ink is applied using an inkjet head (IJ).

[0104] The inkjet head IJ may be a shuttle head, but from the viewpoint of increasing the speed of image recording, a line head is preferred, in which a large number of discharge ports (nozzles) are arranged along the width direction of the long film-shaped image recording substrate A1. There may be only one inkjet head IJ or there may be multiple.

[0105] The inkjet head IJ consists of four inkjet heads corresponding to four colors, such as cyan, magenta, yellow, and black (for example, these four inkjet heads are arranged in the transport direction of the image recording substrate A1).

[0106] In image recording using the inkjet recording device 100, first, the image recording substrate A1, which is wound in a roll shape, is unwound by the unwinding device R1. The unwound image recording substrate A1 is then transported in the direction of the block arrow while tension P is applied. Ink is applied to the transported image recording substrate A1 by the inkjet head IJ, and an image is recorded by irradiating it with active energy rays from light sources L1, L2, L3, and L4, respectively. Finally, the image recording substrate A1 with the image and tension P applied is wound up by the winding device R2, which includes a winding core.

[0107] The tension P is preferably 1 N / m to 2000 N / m, more preferably 10 N / m to 1000 N / m, and even more preferably 50 N / m to 500 N / m. A tension P of 1 N / m or more suppresses transport flutter and streak defects in multi-color images. A tension P of 2000 N / m or less further suppresses inter-color positional shifts in multi-color images.

[0108] The transport speed of the image recording substrate A1 is preferably 5 m / min to 100 m / min, and more preferably 20 m / min to 50 m / min.

[0109] The inkjet recording device 100 has four light sources, but the number of light sources is not particularly limited. In the inkjet recording device 100, the illuminance of the active energy rays emitted from the light sources can be adjusted. The irradiation time can be adjusted by the transport speed of the image recording substrate A1.

[0110] Specifically, the inkjet recording device 100 sets the maximum illuminance of the active energy rays to 9.0 W / cm². ２ Adjust the settings as follows, adjusting the irradiation time to 0.075 seconds or longer, and the integrated exposure dose to 0.3 J / cm². ２ ~3.0 J / cm ２Adjust accordingly. The preferred configuration of the irradiation conditions for the active energy rays is as described above.

[0111] The maximum illuminance of the active energy rays is 2 W / cm². ２ ~7W / cm ２ It is preferable to adjust the cumulative exposure to 0.4 J / cm². ２ ~2.0 J / cm ２ It is preferable to adjust it to the following: There are two or more light sources in the transport direction, and the exposure amount of the active energy rays irradiated from each light source is 0.6 J / cm². ２ It is preferable to adjust it to less than 2 W / cm². Furthermore, there should be two or more light sources in the transport direction, and the illuminance of the active energy rays emitted from each light source should be 2 W / cm². ２ ~8W / cm ２ It is preferable to adjust the settings so that the illuminance is higher towards the downstream side in the conveying direction.

[0112] Furthermore, as shown in Figure 1, it is preferable that the inkjet recording apparatus 100 is equipped with a cooling unit S1 for cooling the image recording substrate A1. It is preferable that the image recording substrate A1 is cooled in the cooling unit S1 before the light source irradiates with active energy rays, while the light source irradiates with active energy rays, or both. The cooling unit S1 can be provided, for example, at a position facing the light source, at any position upstream of the light source L1 in the transport direction, or both. The surface temperature of the image recording substrate tends to rise when irradiated with active energy rays, so from the viewpoint of cooling effect, it is preferable that the cooling unit S1 be provided at a position facing the light source.

[0113] Preferably, the inkjet recording apparatus 100 is equipped with a detection unit (not shown) downstream of the light source L4 in the transport direction for detecting the surface temperature of the image recording substrate A1. The detection unit detects the surface temperature of the image recording substrate A1 at the time when irradiation with active energy rays is completed. Preferably, the cooling unit S1 adjusts the cooling intensity based on the surface temperature value obtained by the detection unit. For example, the cooling unit S1 determines whether the surface temperature obtained by the detection unit is in the range of 10°C to 35°C, and if it is less than 10°C, it weakens the cooling intensity, and if it is more than 35°C, it strengthens the cooling intensity.

[0114] The present disclosure will be further described below with reference to examples, but the present disclosure is not limited to the following examples unless it exceeds the spirit of the disclosure.

[0115] <Preparation of Cyanide Pigment Dispersion> Mix the following components and stir using a mixer (Silverson L4R) at 25°C at 5000 rpm for 20 minutes to obtain a preliminary dispersion. Place the obtained preliminary dispersion into a disperser motor mill M50 (Eiger), and disperse using zirconia beads with a diameter of 0.65 mm at a peripheral speed of 9 m / s for 4 hours to obtain a cyanide pigment dispersion. • Cyanide pigment: PB15:3 (Pigment Blue 15:3); Product name "IRGALITE BLUE GLVO", manufactured by BASF… 30 parts by mass • Dispersant: BYK-168: Product name "DISPERSE BYK-168", manufactured by BYK… 20 parts by mass • PEA: Phenoxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd… 50 parts by mass

[0116] <Preparation of Magenta Pigment Dispersion> Mix the following components and stir for 20 minutes at 5000 rpm at 25°C using a mixer (Silverson L4R) to obtain a preliminary dispersion. Place the obtained preliminary dispersion into a disperser motor mill M50 (Eiger), and disperse using zirconia beads with a diameter of 0.65 mm at a peripheral speed of 9 m / s for 4 hours to obtain a magenta pigment dispersion.

[0117] • Magenta pigment: Pigment Red 254 (product name "Irgazin Red L 3670 HD", manufactured by DIC Corporation) ... 20 parts by mass • Dispersant: Product name "EFKA PX 4701", manufactured by BASF Corporation ... 4 parts by mass • Dispersant: Polymer A manufactured by the manufacturing method described later ... 12 parts by mass • PEA: Phenoxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. ... 63 parts by mass • Polymerization inhibitor: Product name "FLORSTAB UV12", manufactured by Kromachem Corporation (a mixture of the active ingredient N-nitroso-N-phenylhydroxylamine aluminum salt and PEA, with a mixing ratio of 1:9) ... 1 part by mass

[0118] -Method for producing Polymer A- A basic polymer dispersant is prepared as follows and used for dispersing pigments. A monomer mixture of amine monomer 1 (8.0 g), oligomer 1 (16.0 g), and methyl ethyl ketone (30.0 g) is introduced into a nitrogen-purged three-necked flask and heated to 65°C while stirring with a stirrer and flowing nitrogen into the flask. Subsequently, the following two steps are carried out. Step 1: Add only 60 mg of V-65 to the above mixture and heat and stir at 65°C for 1 hour. Step 2: Add only 60 mg of V-65 and heat and stir at 65°C for another hour. The resulting reaction solution is poured into 1,000 mL of hexane while stirring, the resulting precipitate is heated and dried, and then redissolved in PEA to obtain a synthetic dispersant solution (1) with a solid content of 30%. The weight-average molecular weight (polystyrene equivalent) of the polymer measured by GPC is 20,000. The compounds used as raw materials are as follows. Amine monomer 1: 3-dimethylaminopropylacrylamide (manufactured by KJ Chemicals Co., Ltd.) Oligomer 1: Poly(methyl methacrylate) macromonomer having a methacryloyl group at the terminal, trade name: AA-6 (manufactured by Toagosei Co., Ltd.) V-65: 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0119] <Preparation of Yellow Pigment Dispersion> Mix the following components and stir for 20 minutes at 5000 rpm at 25°C using a mixer (Silverson L4R) to obtain a preliminary dispersion. Place the obtained preliminary dispersion into a disperser motor mill M50 (Eiger), and disperse using zirconia beads with a diameter of 0.65 mm at a peripheral speed of 9 m / s for 4 hours to obtain a yellow pigment dispersion. • Yellow pigment: PY155 (Pigment Yellow 155) (Product name "INKJET YELLOW 4GC", manufactured by Heubach) ... 33.9 parts by mass • Dispersant: Product name "Solsperse 32000", manufactured by Lubrizol ... 6.8 parts by mass • PEA: Phenoxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. ... 58.2 parts by mass • Polymerization inhibitor: Product name "FLORSTAB UV12", manufactured by Kromachem (a mixture of the active ingredient N-nitroso-N-phenylhydroxylamine aluminum salt and PEA, with a mixing ratio of 1:9) ... 1.1 parts by mass

[0120] <Preparation of Black Pigment Dispersion> Mix the following components and stir for 20 minutes at 5000 rpm at 25°C using a mixer (Silverson L4R) to obtain a preliminary dispersion. Place the obtained preliminary dispersion into a disperser motor mill M50 (Eiger), and disperse using zirconia beads with a diameter of 0.65 mm at a peripheral speed of 9 m / s for 4 hours to obtain a black pigment dispersion. • Black pigment: Product name "Special Black 250" (manufactured by Orion) ... 40 parts by mass • Dispersant: Product name "EFKA 7731", manufactured by BASF ... 12 parts by mass • PEA: Phenoxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. ... 46.5 parts by mass • Polymerization inhibitor: Product name "FLORSTAB UV12", manufactured by Kromachem (a mixture of the active ingredient N-nitroso-N-phenylhydroxylamine aluminum salt and PEA, with a mixing ratio of 1:9) ... 1.5 parts by mass

[0121] <Preparation of Inks C1-C4, M1, Y1, Bk1> Mix each of the above pigment dispersions with the other components to prepare each ink so that the content of each component listed in Table 1 is as listed in Table 1.

[0122] The details of each component in Table 1 are as follows:

[0123] (Monofunctional polymerizable monomers) • EOEOEA: Ethoxydiethylene glycol acrylate • CHA: Cyclohexyl acrylate • THFA: Tetrahydrofurfuryl acrylate • NVC: N-vinyl-ε-caprolactam • PEA: Phenoxyethyl acrylate • IBOA: Isobornyl acrylate

[0124] (Polyfunctional polymerizable monomer) ・NPGPODA: Neopentyl glycol propylene oxide diacrylate

[0125] (Polyfunctional polymerizable oligomer) ・Ebecryl4101: Urethane acrylate (Molecular weight: 2587)

[0126] (Colorants) - Cyan pigment: PB15:3 (Pigment Blue 15:3); Product name "IRGALITE BLUE GLVO", manufactured by BASF - Magenta pigment: Pigment Red 254 (Product name "Irgazin Red L 3670 HD", manufactured by DIC) - Yellow pigment: PY155 (Pigment Yellow 155) (Product name "INKJET YELLOW 4GC", manufactured by Heubach) - Black pigment: Product name "Special Black 250" (manufactured by Orion)

[0127] (Dispersant) ・BYK-168: Product name "DISPERSE BYK-168", manufactured by BYK Corporation ・Polymer A: Polymer manufactured by the above manufacturing method ・EFKA PX 4701: Product name "EFKA PX 4701", manufactured by BASF Corporation ・EFKA 7731: Product name "EFKA 7731", manufactured by BASF Corporation ・Sol. 32000: Product name "Solsperse 32000", manufactured by Lubrizol Corporation

[0128] (Sensitizer) DETX: 2,4-diethylthioxanthone

[0129] (Photopolymerization initiator) ・Omni. 819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (product name "Omnirad 819", manufactured by IGM Resins B.V.)

[0130] (Polymerization inhibitors) ・TEMPOL: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, manufactured by Tokyo Chemical Industry Co., Ltd. ・UV-12: Product name "FLORSTAB UV12", manufactured by Kromachem

[0131] (Resin) ・Polymer B: A polymer manufactured by the following manufacturing method.

[0132] -Method for producing Polymer B- Weigh 1-propanol (203.7 g) and N-vinyl-ε-caprolactam (NVC) (127.5 g) into a 1 L three-necked flask equipped with a condenser, and heat and stir at 75°C under a nitrogen stream. Separately, a mixed solution prepared by mixing 1-propanol (135.8 g), hydroxyethyl methacrylate (HEMA) (7.5 g), X-22-174ASX (methacrylate-modified silicone) (manufactured by Shin-Etsu Chemical Co., Ltd.) (15.0 g), and V-601 (2,2'-azobis(isobutyrate)dimethyl; polymerization initiator manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (10.5 g) is added dropwise to the flask over 3 hours. After the dropwise addition is complete, stir at 75°C for another hour, raise the temperature to 90°C and react for another 3 hours. The mixture is allowed to cool to room temperature (25°C; the same applies hereafter). Then, phenoxyethyl acrylate (PEA) (350.0 g) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) (3.5 g) are added, and 1-propanol is removed by distillation under reduced pressure conditions of 80°C / 50 hPa to obtain a 30% by mass phenoxyethyl acrylate (PEA) solution of polymer B (a copolymer of NVC / HEMA / one-terminated methacrylic-modified silicone = 85 / 5 / 10 (mass ratio)). The weight-average molecular weight of polymer B is 5000.

[0133] [Examples 1 to 27, Comparative Examples 1 to 4] <Image Recording> Image recording is performed as follows using each ink shown in Tables 2 to 6. As the image recording device, an inkjet recording device as shown in Figure 1 is used, which is equipped with an inkjet head (product name "Samba G3L", manufactured by Fujifilm Corporation) and an LED light source (UV-LED irradiator with a peak wavelength of 385 nm (product name "G5A", manufactured by Kyocera Corporation)).

[0134] In Examples 1 to 17, Examples 20 to 27, and Comparative Examples 1 to 4, a polyvinyl chloride substrate (manufactured by Okamoto Co., Ltd., Tg 30°C, thickness 80 μm) was used as the image recording substrate. In Example 18, a polyvinyl chloride substrate (manufactured by Okamoto Co., Ltd., Tg 20°C, thickness 80 μm) was used as the image recording substrate. In Example 19, a polyvinyl chloride substrate (product name "Flexible Polyvinyl Chloride Sheet", manufactured by Kokugo Co., Ltd., Tg 30°C, thickness 30 μm) was used as the image recording substrate.

[0135] The image recording substrate is attached to a stainless steel plate. The stainless steel plate with the image recording substrate attached is placed on a cooling unit, a cool plate (product name "ZCP-15150", manufactured by AS ONE Corporation), and cooled to a predetermined temperature before being transported into the image recording device. It is transported inside the image recording device at the transport speeds shown in Tables 2 to 6. The cooling unit is set to the cooling temperature shown in Tables 2 to 6 to cool the image recording substrate. In Example 24, the cooling unit is not installed.

[0136] Ink is ejected from the inkjet head and applied to a 5cm x 15cm rectangular area on the image recording substrate, with a resolution of 1200 x 1200 dpi (dots per inch) and an ink volume of 6.0 g / m². ２ Under these conditions, the ink is applied to form a 100% solid image. The applied ink is then irradiated with ultraviolet light using an LED light source to obtain an image. The ultraviolet light is irradiated according to the irradiation conditions for active energy rays shown in Tables 2 to 6. In Examples 1 to 14, Examples 18 to 27, and Comparative Examples 1 to 4, the irradiance and irradiation time of the ultraviolet light irradiated from each light source are kept constant. In Examples 15 to 17, the irradiance of the ultraviolet light irradiated from each light source is varied each time. In Table 4, the irradiance of the ultraviolet light irradiated from light source 1, light source 2, light source 3, and light source 4 are shown from left to right in the "Irradiance for Each Time" column. As a result, an image recording material including an image recording substrate and a solid image is obtained.

[0137] A radiation thermometer is installed within 5 cm of the light source located furthest downstream in the transport direction. The surface temperature of the image recording substrate is measured using the radiation thermometer. This is indicated as "Surface temperature after exposure" in Tables 2 to 6.

[0138] <Manufacturing of Laminated Body> A polyvinyl chloride substrate (product name "SG800", manufactured by KN Trading Co., Ltd., 75 μm thick) is used as the laminating substrate. The laminating substrate is placed on the image in the image recording material obtained above (i.e., on the image recorded on the image recording substrate). In this state, the image recording material and the laminating substrate are heat-pressed together using a desktop automatic transfer press (product name "AF-54TEN", Asahi Textile Machinery Co., Ltd.). This obtains a laminated body having a layered structure of image recording substrate / image / laminating substrate. The lamination temperature (i.e., heat-pressure temperature) is 160°C. The lamination pressure (i.e., heat-pressure pressure) is 0.52 MPa, and the lamination time (i.e., heat-fusion time) is 160 seconds.

[0139] The following evaluates the laminate strength and the deformation of the image recording substrate (in the table, "Substrate Deformation").

[0140] <Laminate Strength> A sample for evaluating laminate strength is prepared using the following method. A 3.2 cm × 3.2 cm image recording sample is cut from the image recording obtained from the image recording described above. Also, a 3.2 cm × 3.2 cm laminate substrate sample is cut from the laminate substrate described above. A 12 μm thick PET (polyethylene terephthalate) sheet is placed on the image recording surface of the image recording sample, in a 1.0 cm × 3.2 cm area including one side of the image recording sample. Next, a 3.2 cm × 3.2 cm laminate substrate sample is placed over the entire area on the image recording surface of the image recording sample, including the area where the PET sheet is placed (1.0 cm × 3.2 cm area) and the area where the PET sheet is not placed (2.2 cm × 3.2 cm area). In this state, the image recording sample and the laminate substrate sample are laminated under the same conditions as the lamination process described above. By removing the PET sheet from the resulting laminate, an evaluation sample is obtained.

[0141] In the evaluation sample, the area where the PET sheet was not placed before the lamination process adheres to the image recording sample and the lamination substrate sample. On the other hand, in the evaluation sample, the area where the PET sheet was placed before the lamination process does not adhere to the image recording sample and the lamination substrate sample. Next, in the area where the image recording sample and the lamination substrate sample do not adhere, a tensile test is performed by pulling the image recording sample and the lamination substrate sample in opposite directions to measure the peel strength. The tensile test is performed using a tensile testing machine (product name "Autograph AGS-X 5KN", manufactured by Shimadzu Corporation). Two evaluation samples are prepared, and the tensile test is performed twice. The average value of the peel strength from the two tests is calculated as the "lamination strength," and the lamination strength of the laminate is evaluated based on the evaluation criteria below. In the evaluation criteria below, the rank that is best for lamination strength is "5." 5: Lamination strength is 7 N / cm or higher. 4: Lamination strength is 3 N / cm or more and less than 7 N / cm. 3: Lamination strength is 2 N / cm or more and less than 3 N / cm. 2: Lamination strength is 1 N / cm or more and less than 2 N / cm. 1: Lamination strength is 0.1 N / cm or more and less than 1 N / cm. 0: Lamination strength is less than 0.1 N / cm.

[0142] <Substrate Deformation> The degree of deformation of the image recording substrate (i.e., the image recording object) after recording an image is evaluated. Specifically, the image recording object is placed on a flat surface and its height is measured using a white light interference microscope (product name "Contour GT-I", manufactured by Bruker). The height of the highest part relative to the flat surface is evaluated as the height difference due to unevenness. The evaluation criteria are as follows: 5: Height difference is less than 0.5 mm. 4: Height difference is 0.5 mm or more and less than 1 mm. 3: Height difference is 1 mm or more and less than 2 mm. 2: Height difference is 2 mm or more and less than 3 mm. 1: Height difference is 3 mm or more.

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] As shown in Tables 2 to 6, Examples 1 to 27 include the steps of applying an active energy ray-curable ink to an image recording substrate containing a polymer with vinyl chloride as a constituent unit using an inkjet recording method, and recording an image by irradiating the applied active energy ray-curable ink with active energy rays, wherein the maximum illuminance of the active energy rays is 9.0 W / cm². ２ The following conditions must be met: the irradiation time is 0.075 seconds or longer, and the cumulative exposure is 0.3 J / cm². ２ ~3.0 J / cm ２ Therefore, the resulting laminated material has excellent lamination strength.

[0150] On the other hand, in Comparative Examples 1 and 2, the maximum illuminance of the active energy rays was 9.0 W / cm². ２ In Comparative Example 3, the irradiation time of the active energy ray was less than 0.075 seconds, resulting in inferior laminate strength. In Comparative Example 4, the integrated exposure amount of the active energy ray was 3.0 J / cm². ２ It is extremely thin, but has inferior lamination strength.

[0151] In Example 1, the maximum illuminance of the active energy rays was 2 W / cm². ２ ~7W / cm ２ Therefore, it exhibits superior lamination strength compared to Examples 2 and 3.

[0152] In Examples 5 and 6, the cumulative exposure dose was 0.4 J / cm². ２ ~2.0 J / cm ２ Therefore, it exhibits superior lamination strength compared to Examples 4 and 7.

[0153] In Examples 8 and 9, the activated energy beam was irradiated two or more times, with an exposure dose of 0.6 J / cm² per irradiation. ２ This is less than the value in Example 10, and the deformation of the image recording substrate is suppressed.

[0154] In Example 17, the activated energy rays were irradiated two or more times, and the irradiance of the activated energy rays was 2 W / cm² in each case. ２ ~8W / cm ２ Therefore, by gradually increasing the irradiance of the active energy rays with each irradiation, deformation of the image recording substrate is suppressed compared to Examples 15 and 16.

[0155] In Example 1, the glass transition temperature of the image recording substrate is 25°C or higher, and deformation of the image recording substrate is suppressed compared to Example 18.

[0156] In Example 1, the thickness of the image recording substrate is 50 μm or more, and deformation of the image recording substrate is suppressed compared to Example 19.

[0157] In Example 1, the process includes a step of cooling the image recording substrate before the step of irradiating it with active energy rays, which suppresses deformation of the image recording substrate compared to Example 24.

[0158] In Example 1, the surface temperature of the image recording substrate after irradiation with active energy rays was 10°C or higher, and the laminate strength was superior compared to Example 20. In Example 1, the surface temperature of the image recording substrate after irradiation with active energy rays was 35°C or lower, and the deformation of the image recording substrate was suppressed compared to Example 24.

[0159] In Example 25, the proportion of monofunctional polymerizable monomers in the polymerizable monomers was 80% by mass or more, and the proportion of polymerizable monomers with a molecular weight of 205 or less in the polymerizable monomers was 80% by mass or more, resulting in superior laminate strength compared to Example 26.

[0160] <Example 100> Four inks, ink C1, ink M1, ink Y1, and ink Bk1, are ejected sequentially from the inkjet head, and image recording is performed in the same manner as in Example 1, except that ultraviolet light is irradiated according to the activation energy ray irradiation conditions shown in Table 7. A laminate body is also manufactured in the same manner as in Example 1, and evaluated in the same manner as in Example 1.

[0161]

[0162] As shown in Table 7, even when using a four-color ink set, it is possible to manufacture laminates with excellent lamination strength.

[0163] Furthermore, the disclosure of Japanese Patent Application No. 2025-027159, filed on 21 February 2025, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

[0164] 100 Inkjet recording device A1 Image recording substrate L1, L2, L3, L4 Light source S1 Cooling unit R1 Unwinding device IJ Inkjet head R2 Winding device

Claims

1. The process includes the steps of: applying an active energy ray-curable ink to an image recording substrate containing a polymer with vinyl chloride as a constituent unit using an inkjet recording method; and recording an image by irradiating the applied active energy ray-curable ink with active energy rays, wherein the maximum illuminance of the active energy rays is 9.0 W / cm². ２ The following conditions must be met: the irradiation time is 0.075 seconds or longer, and the cumulative exposure is 0.3 J / cm². ２ ~3.0 J / cm ２ This is an image recording method.

2. The maximum illuminance of the active energy rays is 2 W / cm². ２ ~7W / cm ２ The image recording method according to claim 1.

3. The cumulative exposure amount is 0.4 J / cm². ２ ~2.0 J / cm ２ The image recording method according to claim 1.

4. In the process of recording the image, the active energy ray is irradiated two or more times, and the exposure amount per exposure is 0.6 J / cm². ２ The image recording method according to claim 1, wherein the value is less than [value missing].

5. In the step of recording the image, the active energy ray is irradiated two or more times, and the illuminance of the active energy ray is 2 W / cm ２ to 8 W / cm ２ and the illuminance of the active energy ray is increased stepwise each time it is irradiated. The image recording method according to claim 1.

6. The image recording method according to claim 1, wherein the image recording substrate has a glass transition temperature of 25°C or higher.

7. The image recording method according to claim 1, wherein the image recording substrate has a thickness of 50 μm or more.

8. The image recording method according to claim 1, further comprising the step of cooling the image recording substrate before the step of recording the image.

9. The image recording method according to claim 1, wherein the surface temperature of the image recording substrate at the time when the irradiation of the active energy ray is completed is 10°C to 35°C.

10. The image recording method according to claim 1, wherein the active energy ray curable ink contains polymerizable monomers, the proportion of monofunctional polymerizable monomers in the polymerizable monomers is 80% by mass or more, and the proportion of polymerizable monomers having a molecular weight of 205 or less in the polymerizable monomers is 80% by mass or more.

11. A method for producing a laminate, comprising the steps of: recording an image on an image recording substrate using the image recording method described in any one of claims 1 to 10; and laminating a laminate substrate containing a polymer with vinyl chloride as a constituent unit onto the surface of the image.

12. An image recording method used in any one of claims 1 to 10, comprising: an inkjet head for applying the active energy ray-curable ink onto the image recording substrate; and a light source for irradiating the active energy ray, wherein the maximum illuminance of the active energy ray is 9.0 W / cm². ２ Adjust the settings as follows, adjusting the irradiation time to 0.075 seconds or longer, and the integrated exposure dose to 0.3 J / cm². ２ ~3.0 J / cm ２ An image recording device that records images by adjusting the settings.

13. The image recording apparatus according to claim 12, comprising: a cooling unit for cooling the image recording substrate; and a detection unit for detecting the surface temperature of the image recording substrate at the time when the irradiation of the active energy ray is completed, wherein the cooling unit adjusts the cooling intensity based on the surface temperature value obtained by the detection unit.

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