Method for producing laminate, inkjet ink, and image recording method

Abstract

Provided are a method for producing a laminate and an application thereof, the method comprising: a step for recording an image by applying an ink to an image recording substrate containing a polymer containing vinyl chloride as a constituent unit by means of an ink jet recording method; and a step in which a lamination substrate containing a polymer containing vinyl chloride as a structural unit is disposed on the image and lamination is performed. The ink contains: a polymerizable monomer A having a (meth) acryloyl group and a molecular weight of 215 or less and a solubility parameter of 16.5-21.3 MPa1 / 2; and an N-vinyl compound. The weighted average of the glass transition temperatures when all polymerizable monomers included in the ink are each used as homopolymers is 0-100 DEG C.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminate, an inkjet ink, and an image recording method. Background Art

[0002] Conventionally, various studies have been conducted on image recording using ink.

[0003] For example, Japanese Patent Application Laid-Open No. 2021-161182 discloses an ink composition which is an energy ray-curable ink composition containing (A) a polymerizable compound, (B) a photopolymerization initiator, (C) an ultraviolet absorber, and / or (D) a radical scavenger, characterized in that (A) the polymerizable compound contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, the monofunctional polymerizable compound contains at least one monofunctional polymerizable compound (a) selected from the group consisting of a monofunctional polymerizable compound (a-1) having a molecular weight of 250 g / mol or less and a melting point of 25°C or higher, a monofunctional polymerizable compound (a-2) having a molecular weight of 250 g / mol or less, a melting point lower than 25°C, and a viscosity at 25°C of 20 mPa·s or higher, and a monofunctional polymerizable compound (a-3) having an amide group and a cyclic structure other than the monofunctional polymerizable compound (a-1) and the monofunctional polymerizable compound (a-2). Summary of the Invention

[0004] Technical Problem to be Solved by the Invention

[0005] Sometimes, after recording an image on an image recording substrate containing a polymer containing vinyl chloride as a structural unit (for example, polyvinyl chloride) to obtain an image recording object, a laminate substrate containing a polymer containing vinyl chloride as a structural unit is laminated on the image in the image recording object to manufacture a laminate. In this case, it is required to improve the adhesion between the image recording substrate and the image and the adhesion between the image and the laminate substrate.

[0006] The present invention has been completed in view of such circumstances, and an object of one embodiment of the present invention is to provide a method for manufacturing a laminate having excellent adhesion between a substrate containing a polymer containing vinyl chloride as a structural unit and an image.

[0007] Another object of another embodiment of the present invention is to provide an inkjet ink capable of recording an image having excellent adhesion to a substrate containing a polymer containing vinyl chloride as a structural unit.

[0008] Another object of another embodiment of the present invention is to provide an image recording method capable of recording an image having excellent adhesion to a substrate containing a polymer containing vinyl chloride as a structural unit.

[0009] Means for solving technical problems

[0010] The present invention includes the following methods.

[0011] <1>A method for manufacturing a laminate, comprising: a step of recording an image by applying an ink by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit; and a step of laminating by disposing a lamination substrate containing a polymer containing vinyl chloride as a structural unit on the image. The ink contains: a polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 and an N-vinyl compound, and the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0°C to 100°C.

[0012] <2>The method for manufacturing a laminate according to <1>, wherein the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more.

[0013] <3>The method for manufacturing a laminate according to <1> or <2>, wherein the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.5 or more.

[0014] <4>The method for manufacturing a laminate according to any one of <1> to <3>, wherein the proportion of the polymerizable monomer having a molecular weight of 205 or less in all the polymerizable compounds contained in the ink is 80% by mass or more.

[0015] <5>The method for manufacturing a laminate according to any one of <1> to <4>, wherein the proportion of the monofunctional polymerizable compound in all the polymerizable compounds contained in the ink is 90% by mass or more.

[0016] <6>The method for manufacturing a laminate according to any one of <1> to <5>, wherein the polymerizable monomer A contains at least 1 selected from the group consisting of cyclic trimethylolpropane formal acrylate and ethoxydiethylene glycol acrylate.

[0017] <7>The method for manufacturing a laminate according to any one of <1> to <6>, wherein the ink further contains at least 1 selected from the group consisting of vinyl chloride-vinyl acetate copolymer and polyester resin.

[0018] <8>The method for manufacturing a laminate according to any one of <1> to <6>, wherein the ink further contains a resin T containing at least one group selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

[0019] <9>The method for manufacturing a laminate according to <8>, wherein the resin T contains a structural unit derived from a polymerizable monomer having a solubility parameter of 16.5 MPa 1 / 2 to 24.0 MPa 1 / 2 and the structural unit.

[0020] <10>The method for manufacturing a laminate according to any one of <1> to <9>, wherein the ink does not contain a surfactant, or the content of the surfactant is less than 0.1% by mass relative to the total amount of the ink.

[0021] <11>The method for manufacturing a laminate according to any one of <1> to <10>, wherein in the lamination step, the image and the lamination substrate are thermocompression bonded at a temperature of 100 °C or higher.

[0022] <12>The method for manufacturing a laminate according to any one of <1> to <11>, wherein in the lamination step, they are overlapped and laminated in such a manner that the image contacts the lamination substrate.

[0023] <13>An inkjet ink, comprising: a polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 to 21.3 MPa 1 / 2 and an N-vinyl compound, wherein the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the inkjet ink as homopolymers is 0 °C to 100 °C, and the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more.

[0024] <14>The inkjet ink according to <13>, wherein the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.5 or more.

[0025] <15>The inkjet ink according to <13> or <14>, wherein the proportion of the polymerizable monomer having a molecular weight of 205 or less in all the polymerizable compounds contained in the inkjet ink is 80% by mass or more.

[0026] <16>The inkjet ink according to any one of <13> to <15>, wherein the proportion of the monofunctional polymerizable compound in all the polymerizable compounds contained in the inkjet ink is 90% by mass or more.

[0027] <17>The inkjet ink according to any one of <13> to <16>, wherein the polymerizable monomer A contains at least one selected from the group consisting of cyclic trimethylolpropane formal acrylate and ethoxydiethylene glycol acrylate.

[0028] <18>The inkjet ink according to any one of <13> to <17>, wherein the inkjet ink further contains at least one selected from the group consisting of vinyl chloride-vinyl acetate copolymer and polyester resin.

[0029] <19>The inkjet ink according to any one of <13> to <18>, wherein the inkjet ink further contains a resin T containing at least one group selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

[0030] <20>The inkjet ink according to <19>, wherein the resin T contains a structural unit derived from a polymerizable monomer having a solubility parameter of 16.5 MPa 1 / 2 ~24.0 MPa 1 / 2 of the polymerizable monomer.

[0031] <21>The inkjet ink according to any one of <11> to <16>, wherein the inkjet ink does not contain a surfactant, or the content of the surfactant is less than 0.1% by mass relative to the total amount of the inkjet ink.

[0032] <22>An image recording method, which includes a step of recording an image by applying the inkjet ink according to any one of <13> to <21> by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit.

[0033] Advantages of the Invention

[0034] According to an embodiment of the present invention, there is provided a method for manufacturing a laminate having excellent adhesion between a substrate containing a polymer containing vinyl chloride as a structural unit and an image.

[0035] According to another embodiment of the present invention, there is provided an inkjet ink capable of recording an image having excellent adhesion to a substrate containing a polymer containing vinyl chloride as a structural unit.

[0036] According to another embodiment of the present invention, there is provided an image recording method capable of recording an image having excellent adhesion to a substrate containing a polymer containing vinyl chloride as a structural unit. Detailed Embodiments

[0037] Hereinafter, the method for manufacturing a laminate, the inkjet ink, and the image recording method of the present invention will be described in detail.

[0038] In this specification, a numerical range expressed using "~" indicates a range that includes the numerical values before and after "~" as the minimum value and the maximum value, respectively.

[0039] In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described within a certain numerical range can be replaced with the upper limit value or the lower limit value of another numerically described stepwise range. Moreover, within the numerical ranges described in this specification, the upper limit value or the lower limit value described within a certain numerical range can be replaced with the value shown in the examples.

[0040] In this specification, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, the amount of each component in the composition represents the total amount of the multiple substances present in the composition.

[0041] In this specification, a combination of two or more preferred modes is a more preferred mode.

[0042] In this specification, the term "process" includes not only an independent process, but also includes this term even when it cannot be clearly distinguished from other processes as long as the intended purpose of the process can be achieved.

[0043] In this specification, "image" refers to the entire film formed by sequentially applying a pretreatment liquid and ink, and "image recording" refers to the formation of an image (i.e., a film).

[0044] Moreover, the concept of "image" in this specification also includes a solid image.

[0045] In this specification, "(meth)acrylate" is a concept that includes both acrylate and methacrylate. Moreover, "(meth)acrylic acid" is a concept that includes both acrylic acid and methacrylic acid.

[0046] [Method for manufacturing a laminate]

[0047] The method for manufacturing the laminate of the present invention includes: a step of recording an image by applying ink by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit (hereinafter, also referred to as "image recording step"); and a step of laminating by disposing a lamination substrate containing a polymer containing vinyl chloride as a structural unit on the image (hereinafter, also referred to as "lamination step"), and the ink contains: a molecular weight of 215 or less and a solubility parameter of 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2A polymerizable monomer A having a (meth)acryloyl group; and an N-vinyl compound, and the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0°C to 100°C.

[0048] According to the method for manufacturing a laminate of the present invention, a laminate can be obtained that sequentially includes an image recording substrate, an image recorded on the image recording substrate, and a laminating substrate disposed on the image. The adhesion between the image recording substrate and the image and the adhesion between the image and the laminating substrate of the laminate obtained by the method for manufacturing a laminate of the present invention are excellent.

[0049] The reason for achieving the above effects by the method for manufacturing a laminate of the present invention is presumably as follows.

[0050] The ink used in the method for manufacturing a laminate of the present invention contains a polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 The polymerizable monomer A has a relatively low molecular weight and a solubility parameter within the above range, and thus has a high affinity for the polymer containing vinyl chloride as a structural unit contained in the image recording substrate and excellent solubility with respect to the image recording substrate. In addition, the ink used in the method for manufacturing a laminate of the present invention contains an N-vinyl compound. The N-vinyl compound tends to have the same solubility parameter as the polymerizable monomer A, and thus has a high affinity for the polymer containing vinyl chloride as a structural unit contained in the image recording substrate and excellent solubility with respect to the image recording substrate. It is considered that the adhesion between the image recording substrate and the image is excellent by performing polymerization in a state where a part of the ink is dissolved in the image recording substrate. In addition, the N-vinyl compound coexists with the polymerizable monomer having a (meth)acryloyl group, and thus the polymerization reaction proceeds rapidly and the curability is excellent. As a result, the strength of the image is increased, which contributes to the adhesion.

[0051] Moreover, in the ink used in the method for manufacturing a laminate of the present invention, the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0°C to 100°C. Thereby, the heat softening property of the ink film (i.e., the image) obtained by curing the ink is excellent. Therefore, it is considered that the adhesion between the image and the laminating substrate is excellent.

[0052] In Japanese Patent Laid-Open No. 2021-161182, there is no description focusing on the interaction between the ink or the ink film formed by curing the ink and the substrate containing the polymer containing vinyl chloride as a structural unit.

[0053] Hereinafter, each step in the method for manufacturing the laminate of the present invention will be described.

[0054] <<Image recording step>>

[0055] The image recording step is a step of recording an image by applying an ink by an inkjet recording method onto an image recording substrate containing a polymer containing vinyl chloride as a structural unit.

[0056] <Image recording substrate>

[0057] The image recording substrate contains a polymer containing vinyl chloride as a structural unit.

[0058] The polymer containing vinyl chloride as a structural unit may be a homopolymer of vinyl chloride (i.e., polyvinyl chloride), or may be a copolymer containing vinyl chloride and other monomers other than vinyl chloride as structural units.

[0059] Examples of the copolymer containing vinyl chloride and other monomers other than vinyl chloride as structural 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.

[0060] Among them, the image recording substrate preferably contains polyvinyl chloride.

[0061] The image recording substrate may contain other components in addition to the polymer containing vinyl chloride as a structural unit. Examples of other components include plasticizers, stabilizers, antioxidants, ultraviolet absorbers, binder resins, and white pigments.

[0062] The image recording substrate may have a layer containing a polymer containing vinyl chloride as a structural unit and a surface treatment layer, but from the viewpoint of obtaining the adhesion between the image recording substrate and the image by the dissolution of the ink in the image recording substrate, it is preferably not provided with a surface treatment layer. That is, the surface of the image recording substrate to which the ink is applied preferably contains a polymer containing vinyl chloride as a structural unit.

[0063] The thickness of the image recording substrate is not particularly limited. For example, it is preferably 0.1 μm to 1,000 μm, more preferably 0.1 μm to 800 μm, and further preferably 1 μm to 500 μm.

[0064] <Ink>

[0065] The ink contains: having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter (hereinafter, also referred to as "SP value") of 16.5 MPa1 / 2 ~21.3 MPa 1 / 2 The polymerizable monomer A; and an N-vinyl compound. Hereinafter, a polymerizable monomer having a (meth)acryloyl group, a molecular weight of 215 or less and an SP value of 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 will also be simply referred to as "polymerizable monomer A".

[0066] (Polymerizable monomer A)

[0067] The ink contains at least one polymerizable monomer A.

[0068] The molecular weight of the polymerizable monomer A is 215 or less, preferably 205 or less, more preferably 200 or less. The molecular weight of the polymerizable monomer A being 215 or less represents a relatively low molecular weight. By setting it to 215 or less, the ink is easily soluble in the image recording substrate. As a result, the adhesion between the image recording substrate and the ink film is improved. And if the molecular weight of the polymerizable monomer A is 205 or less, the distance between crosslinking points becomes shorter and the density of the ink film increases, so the peel strength becomes higher.

[0069] The lower limit value of the molecular weight of the polymerizable monomer A is not particularly limited and is, for example, 100. The molecular weight is calculated based on the types and numbers of atoms constituting the compound.

[0070] The SP value of the polymerizable monomer A is 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 , preferably 18 MPa 1 / 2 ~19.5 MPa 1 / 2 . The SP value of the polymerizable monomer A is 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 , whereby the ink has high affinity for the image recording substrate and excellent solubility. By polymerizing in a state where a part of the ink is dissolved in the image recording substrate, the adhesion between the image recording substrate and the image is excellent.

[0071] In the present invention, the SP value of the polymerizable monomer A refers to the Hansen solubility parameter. The Hansen solubility parameter divides the solubility parameter introduced by Hildebrand into three components: a dispersion term δd, a polar term δp, and a hydrogen bond term δh, and represents them in three-dimensional space.

[0072] The SP value δ of the polymerizable monomer A is set to a value calculated using the following formula A.

[0073] SP value (δ) [MPa 1 / 2 = (δd 2 + δp 2+δh 2 ) 1 / 2 …A

[0074] In addition, the dispersion term δd, the polarity term δp, and the hydrogen bond term δh are calculated using the HSPiP (version 4.1.07) software.

[0075] The polymerizable monomer A has a (meth)acryloyl group (preferably an acryloyl group), and more preferably has a (meth)acryloyloxy group (preferably an acryloyloxy group). The N-vinyl compound described later has high activity with respect to the polymerizable monomer having a (meth)acryloyl group, and the polymerization reaction proceeds rapidly. Since the polymerizable monomer A has a (meth)acryloyl group, it coexists with the N-vinyl compound described later in the ink, whereby the polymerization reaction proceeds rapidly and the curability is excellent.

[0076] The number of (meth)acryloyl groups contained in the polymerizable monomer A may be only 1 or 2 or more, but preferably only 1.

[0077] Examples of the polymerizable monomer A include the following compounds.

[0078] Tetrahydrofurfuryl acrylate (SP value: 18.8 MPa 1 / 2 )

[0079] Cyclic trimethylolpropane formal acrylate (SP value: 19.0 MPa 1 / 2 )

[0080] Ethoxydiethylene glycol acrylate (SP value: 18.2 MPa 1 / 2 )

[0081] Cyclohexyl acrylate (SP value: 17.9 MPa 1 / 2 )

[0082] Isobornyl acrylate (SP value: 17.1 MPa 1 / 2 )

[0083] Phenoxyethyl acrylate (SP value: 19.44 MPa 1 / 2 )

[0084] N,N-Dimethylacrylamide (SP value: 21.4 MPa 1 / 2 )

[0085] 4-tert-Butylcyclohexyl acrylate (SP value: 16.7 MPa 1 / 2 )

[0086] 3,3,5-Trimethylcyclohexyl acrylate (SP value: 16.7 MPa 1 / 2 )

[0087] 4-Hydroxybutyl acrylate (SP value: 21.0 MPa 1 / 2 )

[0088] (2-Methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate (SP value: 18.2 MPa 1 / 2 )

[0089] Benzyl acrylate (SP value: 19.0 MPa 1 / 2 )

[0090] (3-Ethyloxetane-3-yl)methyl acrylate (SP value: 18.6 MPa 1 / 2 )

[0091] 2-Oxotetrahydrofuran-3-yl acrylate (SP value: 21.2 MPa 1 / 2 )

[0092] Among them, from the viewpoint of improving the adhesion to the substrate for image recording and the adhesion to the substrate for lamination, the polymerizable monomer A preferably contains at least one selected from the group consisting of tetrahydrofurfuryl acrylate, cyclic trimethylolpropane formal acrylate, and ethoxydiethylene glycol acrylate, and more preferably contains at least one selected from the group consisting of cyclic trimethylolpropane formal acrylate and ethoxydiethylene glycol acrylate.

[0093] The content of the polymerizable monomer A is preferably 30% by mass to 75% by mass, more preferably 40% by mass to 70% by mass, and further preferably 44% by mass to 63% by mass with respect to the total amount of the ink.

[0094] (N-Vinyl compound)

[0095] The ink contains at least one N-vinyl compound.

[0096] The N-vinyl compound is a compound in which a vinyl group is bonded to a nitrogen atom.

[0097] The N-vinyl compound, similarly to the polymerizable monomer A, corresponds to a compound having an SP value of 16.5 MPa 1 / 2 to 21.3 MPa 1 / 2 and has high solubility in the substrate for image recording, and thus contributes to the adhesion between the substrate for image recording and the image.

[0098] Examples of the N-vinyl compound include N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylcarbazole, N-vinylimidazole, N-vinylphthalimide, N-vinylacetamide, N-vinylformamide, and 5-methyl-3-vinyl-2-oxazoline.

[0099] Among them, from the viewpoint of high solubility in the image recording substrate and improving the adhesion between the image recording substrate and the image, the N-vinyl compound is preferably at least one selected from the group including N-vinylcaprolactam and 5-methyl-3-vinyl-2-oxazoline.

[0100] The content of the N-vinyl compound is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 40% by mass, and further preferably 20% by mass to 30% by mass with respect to the total amount of the ink.

[0101] The mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is preferably 0.35 or more, more preferably 0.5 or more. If the above mass ratio is 0.35 or more, the curability of the ink is improved and the adhesion between the image and the lamination substrate is improved.

[0102] Regarding the N-vinyl compound, the glass transition temperature as a homopolymer tends to be relatively high. Therefore, the upper limit value of the above mass ratio is not particularly limited, but from the viewpoint of obtaining thermal softening properties in the ink film, the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is preferably 0.30 to 0.80, more preferably 0.35 to 0.75, and further preferably 0.5 to 0.70.

[0103] In the ink for image recording, the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0°C to 100°C, preferably 5°C to 50°C, and more preferably 10°C to 30°C. If the above weighted average is 0°C to 100°C, the ink film (i.e., the image) obtained by curing the ink has excellent thermal softening properties, and thus the adhesion between the image and the lamination substrate is excellent.

[0104] The glass transition temperature of the polymerizable monomer as a homopolymer is measured by the following method. In addition, the "polymerizable monomer" mentioned here refers to a compound having a polymerizable group and a molecular weight of 1000 or less.

[0105] First, a homopolymer having a weight average molecular weight of 10,000 to 20,000 is produced using the polymerizable monomer. The glass transition temperature of the produced homopolymer is measured according to the method described in JIS K7121:2012.

[0106] In the present invention, the glass transition temperature is measured using a differential scanning calorimeter. For example, it is measured using a product named "DSC-60" manufactured by SHIMADZU CORPORATION.

[0107] In the present invention, the weight-average molecular weight is measured using gel permeation chromatography (GPC). For example, as the GPC, HLC-8220GPC (manufactured by TOSOH CORPORATION) is used. As the column, 3 TSK gel, Super Multipore HZ-H (manufactured by TOSOH CORPORATION, 4.6 mm ID × 15 cm) are used. As the eluent, THF (tetrahydrofuran) is used. As the conditions, the sample concentration is set to 0.45 mass%, the flow rate is set to 0.35 ml / min, the sample injection volume is set to 10 μl, the measurement temperature is set to 40°C, and detection is performed using a differential refractive index (RI) detector. The calibration curve is prepared using 8 samples of the product name "TSK standard polystyrene": "F-40", "F-20", "F-4", "F-1", "A-5000", "A-2500", "A-1000" and "n-propylbenzene" manufactured by Tosoh Corporation as standard samples.

[0108] In addition, depending on the weight-average molecular weight of the homopolymer, the glass transition temperature of the homopolymer varies. However, when the weight-average molecular weight is in the range of 10,000 to 20,000, the variation is negligible.

[0109] The weighted average of the glass transition temperature is calculated using the following formula. In the formula, T i represents the glass transition temperature of the i-th polymerizable monomer contained in the ink as a homopolymer, and C i represents the content (mass%) of the i-th polymerizable monomer relative to the total amount of the ink.

[0110] Weighted average of glass transition temperature = ΣT i C i / ΣC i

[0111] (Other polymerizable compounds)

[0112] The ink may contain polymerizable compounds other than the polymerizable monomer A and the N-vinyl compound as other polymerizable compounds. However, as described above, the types and contents of the other polymerizable compounds are adjusted so that the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0°C to 100°C.

[0113] The polymerizable group possessed by the other polymerizable compounds is preferably a free-radical polymerizable group, more preferably a photo-free-radical polymerizable group, and still more preferably an ethylenically unsaturated group. Examples of the other polymerizable compounds include (meth)acrylate compounds, (meth)acrylamide compounds, vinyl ether compounds, allyl compounds, and unsaturated carboxylic acids.

[0114] The proportion of polymerizable monomers with a molecular weight of 205 or less in all the polymerizable compounds contained in the ink is preferably 80% by mass or more, more preferably 90% by mass or more. If the above proportion is 80% by mass or more, the solubility of the ink in the image recording substrate increases, and the adhesion between the image recording substrate and the image improves. The upper limit value of the above proportion is not particularly limited, and the above proportion can be 100% by mass. That is, all the polymerizable compounds contained in the ink can be polymerizable monomers with a molecular weight of 205 or less.

[0115] In addition, the "polymerizable compound" mentioned here refers to a compound having at least one polymerizable group, and the molecular weight is not particularly limited.

[0116] The proportion of monofunctional polymerizable compounds in all the polymerizable compounds contained in the ink is preferably 90% by mass or more, more preferably 92% by mass or more. If the above proportion is 90% by mass or more, the curing shrinkage caused by residual stress is suppressed, and the adhesion between the image recording substrate and the image improves. The upper limit value of the above proportion is not particularly limited, and the above proportion can be 100% by mass. That is, all the polymerizable compounds contained in the ink can be monofunctional polymerizable compounds.

[0117] In addition, the "polymerizable compound" mentioned here refers to a compound having at least one polymerizable group, and the molecular weight is not particularly limited. The "monofunctional polymerizable compound" refers to a compound having one polymerizable group.

[0118] (Polymerization initiator)

[0119] The ink preferably contains at least one polymerization initiator.

[0120] As the polymerization initiator, a photo radical polymerization initiator that absorbs light to generate radicals as polymerization initiation species is preferred.

[0121] As the polymerization initiator, for example, alkylbenzene ketone compounds, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azine onium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds can be cited.

[0122] Among them, the polymerization initiator is preferably at least one selected from the group consisting of acylphosphine compounds and thio compounds, more preferably at least one selected from the group consisting of acylphosphine oxide compounds and thioxanthone compounds, and further preferably an acylphosphine oxide compound and a thioxanthone compound are used simultaneously.

[0123] As the acylphosphine oxide compound, a monoacylphosphine oxide compound and a bisacylphosphine oxide compound can be mentioned, and a bisacylphosphine oxide compound is preferred.

[0124] As the monoacylphosphine oxide compound, for example, isobutyryldiphenylphosphine oxide, 2-ethylhexanoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, o-toluoyldiphenylphosphine oxide, p-tert-butylbenzoyldiphenylphosphine oxide, 3-pyridylcarbonyldiphenylphosphine oxide, acryloyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, vinyl neopentanoyl phenylphosphinate, adipoyl bisdiphenylphosphine oxide, neopentanoyldiphenylphosphine oxide, p-toluoyldiphenylphosphine oxide, 4-(tert-butyl)benzoyldiphenylphosphine oxide, terephthaloyl bisdiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, neodecanoyldiphenylphosphine oxide, 2-methyl-2-ethylhexanoyldiphenylphosphine oxide, 1-methyl-cyclohexanoyldiphenylphosphine oxide, methyl neopentanoyl phenylphosphinate and isopropyl neopentanoyl phenylphosphinate can be mentioned.

[0125] As the bisacylphosphine oxide compound, for example, 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, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-chlorophenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,4-dimethoxyphenylphosphine oxide, bis(2,6-dichlorobenzoyl)decylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-octylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine 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 can be mentioned.

[0126] Among them, the bisacylphosphine oxide compound preferably contains at least one selected from the group consisting of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (product name “Omnirad 819”, manufactured by IGM Resins B.V.) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product name “Omnirad TPO-H”, manufactured by IGM Resins B.V.).

[0127] As thioxanthone compounds, 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, 3-butoxycarbonyl-7-methylthioxanthone, 1-cyano-3-chlorothioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1-ethoxycarbonyl-3-ethoxythioxanthone, 1-ethoxycarbonyl-3-aminothioxanthone, 1-ethoxycarbonyl-3-phenylsulfonylthioxanthone, 3,4-bis[2-(2-methoxyethoxy)ethoxycarbonyl]thioxanthone, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)thioxanthone, 2-methyl-6-dimethoxymethylthioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, n-allylthioxanthone-3,4-dicarboximide, n-octylthioxanthone-3,4-dicarboximide, N-(1,1,3,3-tetramethylbutyl)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-propanammonium chloride can be mentioned.

[0128] The thioxanthone compound can be a commercially available product. As commercially available products, the SPEEDCURE series (e.g., SPEEDCURE 7010, SPEEDCURE CPTX, SPEEDCURE ITX, etc.) manufactured by Lambson can be mentioned.

[0129] When the ink contains a polymerization initiator, from the viewpoint of improving the curability of the ink, the content of the polymerization initiator is preferably 2% by mass or more, more preferably 5% by mass or more, relative to the total amount of the ink. The upper limit value of the content of the polymerization initiator is not particularly limited, for example, it is 10% by mass.

[0130] (Surfactant)

[0131] The ink can contain at least one surfactant. In the present invention, the surfactant refers to a compound having a surface active function with a molecular weight of less than 1000. The molecular weight is calculated based on the types and numbers of atoms constituting the compound.

[0132] However, from the viewpoint of improving the affinity between the substrate for image recording and the ink, the ink preferably does not contain a surfactant, or the content of the surfactant is less than 0.1% by mass relative to the total amount of the ink. When the ink contains a surfactant, a commonly known surfactant can be used as the surfactant.

[0133] (Polymerization inhibitor)

[0134] The ink of the present invention preferably contains at least one polymerization inhibitor.

[0135] Examples of the polymerization inhibitor include p-methoxyphenol, quinones (e.g., hydroquinone, benzoquinone, methoxybenzoquinone, etc.), phenothiazine, catechols, alkylphenols (e.g., dibutylhydroxytoluene (BHT), etc.), alkylbisphenols, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionate esters, mercaptobenzimidazole, phosphites, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (TEMPOL), and aluminum tris(N-nitroso-N-phenylhydroxylamine) (alias: Cupferron Al).

[0136] Among them, the polymerization inhibitor preferably contains at least one selected from the group consisting of p-methoxyphenol, catechols, quinones, alkylphenols, TEMPO, TEMPOL, and aluminum tris(N-nitroso-N-phenylhydroxylamine), and more preferably contains at least one selected from the group consisting of p-methoxyphenol, hydroquinone, benzoquinone, BHT, TEMPO, TEMPOL, and aluminum tris(N-nitroso-N-phenylhydroxylamine).

[0137] When the ink contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.01% by mass to 2.0% by mass, more preferably 0.02% by mass to 1.0% by mass, and further preferably 0.03% by mass to 0.5% by mass relative to the total amount of the ink.

[0138] (Resin)

[0139] The ink preferably contains at least one resin. In the present invention, "resin" does not have a polymerizable group. In the present invention, a resin having a polymerizable group corresponds to a "polymerizable compound" and is distinguished from the resin. And the resin refers to a compound having a weight average molecular weight of 1000 or more.

[0140] Examples of the resin include epoxy resins, vinyl chloride resins, polyester resins, (meth)acrylic resins, urethane resins, chlorinated polyolefins, and polyketones.

[0141] Vinyl chloride resins refer to polymers containing vinyl chloride as a structural unit. The vinyl chloride resin may be a homopolymer of vinyl chloride (i.e., polyvinyl chloride) or a copolymer containing vinyl chloride and other monomers other than vinyl chloride as structural units.

[0142] As commercially available products of vinyl chloride resins, for example, UCAR Solution Vinyl Resin VYHD, VYHH, VMCA, VROH, VYLF-X manufactured by The Dow Chemical Company; SOLBIN resins CL, CNL, C5R, TA5R manufactured by Nissin Chemical Co., Ltd.; and VINNOL (registered trademark) E15 / 40, E15 / 45, H14 / 36, H15 / 42, H15 / 50, H11 / 59, H40 / 43, H40 / 50, H40 / 55, H40 / 60, H15 / 45M, E15 / 45M, E15 / 40A manufactured by Wacker Chemie AG can be cited.

[0143] As commercially available products of polyester resins, for example, the ELITEL series manufactured by UNITIKA LTD., the BYRON series manufactured by TOYOBO CO., LTD., the ESPEL series manufactured by Hitachi Chemical Co., Ltd., and the TEGO (registered trademark) addbond series manufactured by Evonik Industries AG can be cited.

[0144] As (meth)acrylic resins, for example, a copolymer of methyl methacrylate and n-butyl methacrylate can be cited.

[0145] As commercially available products of (meth)acrylic resins, for example, Elvacite 2013 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw = 34000), Elvacite 2014 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw = 119000), Elvacite 4099 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw = 15000) manufactured by LUCITE International Corporation; Dianal (registered trademark) BR-113 (butyl methacrylate resin, Mw = 30000) manufactured by Mitsubishi Chemical Corporation can be cited.

[0146] Urethane resins refer to polymers having urethane bonds in the main chain. Urethane resins are manufactured, for example, by reacting polyisocyanate compounds with polyol compounds.

[0147] As commercially available products of chlorinated polyolefins, for example, SUPER CRON (registered trademark) 814HS manufactured by Nippon Paper Industries Co., Ltd. can be cited.

[0148] As commercially available products of polyketones, for example, TEGO (registered trademark) VARIPLUS AP, CA, SK manufactured by Evonik Industries AG can be cited.

[0149] Among them, the ink preferably contains at least one selected from the group consisting of vinyl chloride-vinyl acetate copolymers and polyester resins. Vinyl chloride-vinyl acetate copolymers and polyester resins have excellent affinity with the image recording substrate. If these resins are contained in the ink, the solubility of the ink in the image recording substrate increases, and the adhesion between the image recording substrate and the image improves.

[0150] Moreover, the ink preferably contains a resin T containing at least one group selected from the group consisting of fluorinated hydrocarbon groups, polysiloxane groups, and hydrocarbon groups having 12 or more carbon atoms. If the resin contains at least one group selected from the group consisting of fluorinated hydrocarbon groups, polysiloxane groups, and hydrocarbon groups having 12 or more carbon atoms, the solubility of the ink in the image recording substrate increases, and the adhesion between the image recording substrate and the image improves.

[0151] In addition, the ink may contain at least one selected from the group consisting of the above-mentioned vinyl chloride-vinyl acetate copolymers and polyester resins and a resin T containing at least one group selected from the group consisting of fluorinated hydrocarbon groups, polysiloxane groups, and hydrocarbon groups having 12 or more carbon atoms.

[0152] A fluorinated hydrocarbon group means a hydrocarbon group substituted by at least one fluorine atom.

[0153] As fluorinated hydrocarbon groups, fluorinated alkyl groups, fluorinated alkenyl groups, fluorinated aryl groups, etc. can be cited.

[0154] As the fluorinated hydrocarbon group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0155] As the number of fluorine atoms in the fluorinated hydrocarbon group, 6 or more is preferred, and 8 or more is more preferred.

[0156] There is no particular limitation on the upper limit of the number of fluorine atoms in the fluorinated hydrocarbon group. As the upper limit, for example, 40 can be cited.

[0157] As the number of carbon atoms in the fluorinated hydrocarbon group, 3 or more is preferred, and 4 or more is more preferred.

[0158] There is no particular limitation on the upper limit of the number of carbon atoms in the fluorinated hydrocarbon group. As the upper limit, for example, 20 can be cited.

[0159] Examples of the hydrocarbon group having 12 or more carbon atoms include an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an aralkyl group. The hydrocarbon group having 12 or more carbon atoms is particularly preferably an alkyl group.

[0160] The number of carbon atoms in the hydrocarbon group having 12 or more carbon atoms is preferably 14 or more, more preferably 16 or more.

[0161] There is no particular limitation on the upper limit of the number of carbon atoms in the hydrocarbon group having 12 or more carbon atoms. As the upper limit, for example, 30 can be mentioned.

[0162] The polysiloxanyl group means a repeating divalent group containing an Si—O bond.

[0163] The specific resin more preferably contains a monovalent group containing a polysiloxanyl group.

[0164] Examples of the monovalent group containing a polysiloxanyl group include the following group (P).

[0165] [Chemical formula 1]

[0166]

[0167] In the group (P), R P1 and R P2 each independently represents a hydrocarbon group having 1 to 6 carbon atoms or the following group (Z), and R P3 to R P5 each independently represents a hydrocarbon group having 1 to 6 carbon atoms, x represents an integer of 1 to 100, and * represents a bonding position.

[0168] When x is an integer of 2 or more, a plurality of R P1 may be the same or different, and a plurality of R P2 may be the same or different.

[0169] In the group (P), the number of Si—O bonds (i.e., siloxane bonds) is 2 or more.

[0170] [Chemical formula 2]

[0171]

[0172] In the group (Z), R Z1 to R Z5 each independently represents a hydrocarbon group having 1 to 6 carbon atoms, z represents an integer of 0 to 100, and * represents a bonding position.

[0173] When z is an integer of 2 or more, a plurality of R Z1 may be the same or different, and a plurality of R Z2 may be the same or different.

[0174] As x in the group (P), it is preferably an integer of 1 to 50, more preferably an integer of 1 to 20, and particularly preferably an integer of 1 to 10.

[0175] In the group (P), as R P1 ~R P5 The hydrocarbon group having 1 to 6 carbon atoms in R

[0176] As z in the group (Z), it is preferably an integer of 0 to 50, more preferably an integer of 0 to 20, and particularly preferably an integer of 0 to 10.

[0177] In the group (Z), as R Z1 ~R Z5 The hydrocarbon group having 1 to 6 carbon atoms in R

[0178] - a structural unit (1) containing at least one selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms -

[0179] The resin T preferably contains at least one structural unit (1), and the structural unit (1) contains at least one selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

[0180] As the structural unit (1), a structural unit derived from a vinyl monomer (for example, (meth)acrylate, (meth)acrylamide, etc.), a structural unit derived from a diol compound, and a structural unit derived from a diisocyanate compound can be mentioned.

[0181] As the structural unit (1), a structural unit derived from (meth)acrylate is preferred, and a structural unit (1A) described below is more preferred.

[0182] [Chemical formula 3]

[0183]

[0184] In the structural unit (1A), R 31 represents a hydrogen atom or a methyl group, L 31 represents a single bond or a linking group, X 31 represents a fluorinated hydrocarbon group, a monovalent group containing a polysiloxane group, or a hydrocarbon group having 12 or more carbon atoms, and the two * each represent a bonding position.

[0185] X 31 The preferred modes of the fluorinated hydrocarbon group, the monovalent group containing a polysiloxane group, and the hydrocarbon group having 12 or more carbon atoms in X are as described above.

[0186] R 31 represents a hydrogen atom or a methyl group, preferably a methyl group.

[0187] As L 31 the linking group represented, is preferably a divalent hydrocarbon group having 1 to 11 carbon atoms (more preferably 2 to 11 carbon atoms, still more preferably 2 to 8 carbon atoms).

[0188] The above divalent hydrocarbon group may have substituents such as a hydroxyl group and an alkoxy group.

[0189] Examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group, an arylene group, an alkylene arylene group, an alkylene arylene alkylene group, an alkylene carbonyloxy alkylene group, an arylene carbonyloxy alkylene group, etc.

[0190] As the divalent hydrocarbon group, an alkylene group having 1 to 11 carbon atoms (more preferably 1 to 6 carbon atoms) is particularly preferred.

[0191] Specific examples of the structural unit (1A) containing at least one selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxanyl group, and a hydrocarbon group having 12 or more carbon atoms are as follows.

[0192] [Chemical formula 4]

[0193]

[0194] [Chemical formula 5]

[0195]

[0196] Specific examples of the structural unit (1) may also include the following structural units.

[0197] [Chemical formula 6]

[0198]

[0199] In addition to the above structural unit (1), the resin T preferably contains at least one structural unit (2) which contains at least one selected from the group consisting of an alkylthio group, an alkylenesulfide group, and a mercapto group.

[0200] Examples of the structural unit (2) include an alkylthio group, an alkylenesulfide alkylene group, an alkoxysulfide alkoxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms), a mercapto group, a mercaptoalkyl group (preferably having 1 to 10 carbon atoms), a mercaptoalkylamino group (preferably having 1 to 10 carbon atoms), etc.

[0201] From the viewpoint of further suppressing the yellowing of the image, the number of carbon atoms of the alkylthio group is preferably 1 to 30, more preferably 1 to 20, still more preferably 6 to 20, and particularly preferably 10 to 20.

[0202] From the viewpoint of further suppressing the yellowing of the image, the number of carbon atoms of the alkylene thioalkylene is preferably 2 to 20, more preferably 2 to 10.

[0203] Moreover, as the structural unit (2), a structural unit derived from a vinyl monomer (e.g., (meth)acrylate, (meth)acrylamide, etc.) containing at least one selected from the group consisting of an alkylthio group, an alkylene thioalkylene group, and a mercapto group can also be cited.

[0204] As the structural unit (2) containing at least one selected from the group consisting of an alkylthio group, an alkylene thio group, and a mercapto group, from the viewpoint of further suppressing the yellowing of the image, an alkylthio group is preferred, and an alkylthio group as an end group of the main chain of the resin T is particularly preferred.

[0205] Specific examples of the structural unit (2) are as follows.

[0206] [Chemical formula 7]

[0207]

[0208] [Chemical formula 8]

[0209]

[0210] In addition to the above structural unit (1), the resin T preferably contains at least one structural unit (3) containing an amine structure having an α-hydrogen atom.

[0211] As the structural unit (3), a structural unit derived from a vinyl monomer (e.g., (meth)acrylate, (meth)acrylamide, etc.), a structural unit derived from a diol compound, a structural unit derived from a diamine compound, a structural unit derived from a diisocyanate compound, etc. can be cited.

[0212] Here, (meth)acrylate is a raw material of a (meth)acrylic resin, a diisocyanate compound is a raw material of a urethane resin or a urea resin, a diol compound is a raw material of a urethane resin, and a diamine compound is a raw material of a urea resin.

[0213] As the structural unit (3), a structural unit derived from (meth)acrylate is preferred, and the following structural unit (3A) is more preferred.

[0214] [Chemical formula 9]

[0215]

[0216] In the structural unit (3A), R 11 represents a hydrogen atom or a methyl group, R 12 , R 13 and R14 Each independently represents a hydrogen atom or a hydrocarbon group, L 11 represents a linking group, and the two * respectively represent bonding positions. R 12 and L 11 may be connected to each other to form a ring, R 12 and R 13 may be connected to each other to form a ring.

[0217] In the structural unit (3A), R 11 represents a hydrogen atom or a methyl group, preferably a methyl group.

[0218] In the structural unit (3A), as R 12 、R 13 and R 14 The number of carbon atoms of the above-mentioned hydrocarbon groups is preferably 1 to 11, more preferably 1 to 6, and particularly preferably 1 to 3, respectively independently.

[0219] As R 12 、R 13 and R 14 The above-mentioned hydrocarbon groups may include alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, aralkyl groups, etc., preferably alkyl groups or aryl groups, and more preferably alkyl groups.

[0220] R 12 、R 13 and R 14 The above-mentioned hydrocarbon groups may be substituted. As the substituents at this time, hydroxyl groups, alkoxy groups, etc. may be cited.

[0221] As R 13 and R 14 From the viewpoint of further suppressing the viscosity of the image, each is preferably independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and further preferably a hydrogen atom or a methyl group.

[0222] As R 13 and R 14 From the viewpoint of further suppressing the viscosity of the image, both are particularly preferably hydrogen atoms. As R 13 and R 14 The hydrogen atoms are both α-hydrogen atoms. Therefore, when R 13 and R 14 are both hydrogen atoms, the number of α-hydrogen atoms in the amine structure is large, and thus the function of the amine structure (that is, the function of suppressing the inhibition of free radical polymerization caused by oxygen) is more effectively exerted. Therefore, in this case, the viscosity of the image is significantly suppressed.

[0223] As R 12, from the viewpoint of further suppressing the stickiness of the image, it is preferably a hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably an alkyl group having 1 to 3 carbon atoms, still more preferably methyl or ethyl, and particularly preferably methyl.

[0224] In the case where R 12 is a hydrocarbon group (more preferably as described above), compared with the case where R 12 is a hydrogen atom, the stickiness of the image is suppressed. It is considered that the reason is that when R 12 is a hydrocarbon group (more preferably as described above), the formation of N-O radicals is suppressed, and as a result, the function of the amine structure (that is, the function of suppressing the radical polymerization hindrance caused by oxygen) is more effectively exerted.

[0225] In the structural unit (3A), L 11 represents a linking group.

[0226] As the linking group represented by L 11 , a divalent hydrocarbon group having 1 to 11 carbon atoms (more preferably 2 to 11 carbon atoms, still more preferably 2 to 8 carbon atoms) is preferred.

[0227] The above divalent hydrocarbon group may have substituents such as a hydroxyl group and an alkoxy group.

[0228] Examples of the above divalent hydrocarbon group include an alkylene group, an alkenylene group, an arylene group, an alkylene arylene group, an alkylene arylene alkylene group, an alkylene carbonyloxy alkylene group, an arylene carbonyloxy alkylene group, and the like.

[0229] As the above divalent hydrocarbon group, an alkylene group having 1 to 11 carbon atoms (more preferably 1 to 6 carbon atoms) is particularly preferred.

[0230] Specific examples of the structural unit (3) are as follows.

[0231] [Chemical formula 10]

[0232]

[0233] [Chemical formula 11]

[0234]

[0235] In particular, the resin T preferably contains a structural unit derived from a polymerizable monomer having an SP value of 16.5 MPa 1 / 2 to 24.0 MPa 1 / 2 . If the resin T contains a structural unit derived from a polymerizable monomer having an SP value of 16.5 MPa 1 / 2 to 24.0 MPa 1 / 2When a structural unit of a polymerizable monomer is selected from at least one group in the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms, the group is oriented on the surface of the ink film, and the affinity with the laminated substrate is improved.

[0236] The SP value of the polymerizable monomer contained in Resin T is measured by the same method as the SP value of the above polymerizable monomer A.

[0237] The weight average molecular weight (Mw) of the resin is preferably 1,000 to 70,000, more preferably 5,000 to 50,000.

[0238] When the ink contains a resin, the content of the resin is preferably 1% by mass to 10% by mass, more preferably 1.5% by mass to 8% by mass, and still more preferably 2% by mass to 6% by mass, relative to the total amount of the ink.

[0239] (Water)

[0240] The ink may contain a small amount of water.

[0241] Specifically, the content of water is preferably 3% by mass or less, more preferably 2% by mass or less, and particularly preferably 1% by mass or less, relative to the total amount of the ink.

[0242] The ink is preferably a non-aqueous ink that is substantially free of water.

[0243] (Colorant)

[0244] The ink preferably contains at least one colorant.

[0245] There is no particular limitation on the colorant, and it can be arbitrarily selected and used from known color materials such as pigments, water-soluble dyes, and disperse dyes. Among them, from the viewpoints of excellent weather resistance and rich color reproducibility, the colorant is preferably a pigment.

[0246] The type of the pigment is not particularly limited, and it can be either an organic pigment or an inorganic pigment.

[0247] Examples of the pigment include those described in "Encyclopedia Dictionary of Pigments" edited by Shojiro Ito (published in 2000), W. Herbst, K. Hunger "Industrial Organic Pigments: Industrial Organic Pigments", Japanese Patent Publication No. 2002-12607, Japanese Unexamined Patent Application Publication No. 2002-188025, Japanese Unexamined Patent Application Publication No. 2003-26978, and Japanese Unexamined Patent Application Publication No. 2003-342503.

[0248] When the ink uses a pigment as the colorant, a dispersant may be contained as needed.

[0249] Regarding colorants such as pigments and pigment dispersants, publicly known documents such as paragraphs 0152 to 0158 of Japanese Patent Application Laid-Open No. 2011-225848 and paragraphs 0132 to 0149 of Japanese Patent Application Laid-Open No. 2009-209352 can be suitably referred to.

[0250] When the ink contains a colorant, the content of the colorant is preferably 0.1% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, based on the total amount of the ink.

[0251] (Other components)

[0252] The ink may contain other components in addition to the above.

[0253] Examples of other components include ultraviolet absorbers, co-sensitizers, antioxidants, anti-fading agents, conductive salts, and the like.

[0254] Regarding other components, publicly known documents such as Japanese Patent Application Laid-Open No. 2011-225848 and Japanese Patent Application Laid-Open No. 2009-209352 can be suitably referred to.

[0255] (Physical properties of the ink)

[0256] From the viewpoint of ejection properties, the viscosity of the ink is preferably 5 mPa·s to 50 mPa·s, more preferably 10 mPa·s to 30 mPa·s, and further preferably 10 mPa·s to 25 mPa·s.

[0257] The viscosity refers to the value measured at 25°C.

[0258] The viscosity is a value measured using a viscometer. For example, it can be measured using VISCOMETER RE-85L (manufactured by Toki Sangyo Co., Ltd.).

[0259] From the viewpoint of ejection properties, the surface tension of the ink is preferably 60 mN / m or less, more preferably 20 mN / m to 50 mN / m, and further preferably 25 mN / m to 45 mN / m.

[0260] The surface tension refers to the value measured at 25°C.

[0261] The surface tension is a value measured using a surface tensiometer. For example, it can be measured using the product named "Automatic Surface Tentiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.)".

[0262] (Method of imparting the ink)

[0263] The ink is applied by an inkjet recording method.

[0264] The ejection method of the ink in the inkjet recording method is not particularly limited and may be a known method. For example, it may be a charge control method that ejects ink using an electrostatic induction force, a drop-on-demand inkjet method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electrical signal into a sound beam and irradiates it onto the ink to eject the ink using radiation pressure, or a thermal inkjet (Bubble Jet (registered trademark)) method that heats the ink to form bubbles and uses the generated pressure.

[0265] As the inkjet recording method, the inkjet recording method described in Japanese Patent Laid-Open No. 54-59936 can be particularly effectively used. In this inkjet recording method, the ink under the action of heat energy undergoes a rapid volume change, and the ink is ejected from the nozzle by the force generated by this state change. As the inkjet recording method, the method described in paragraphs 0093 to 0105 of Japanese Patent Laid-Open No. 2003-306623 can also be applied.

[0266] The ink is applied to the image recording substrate by the inkjet recording method by ejecting the ink from the nozzle of the inkjet head.

[0267] As the inkjet head method, there are a shuttle method in which a serial head scans in the width direction of the recording medium while recording; and a line method that uses a line head in which recording elements are arranged corresponding to the entire area of one side of the recording medium.

[0268] In the line method, the entire surface of the recording medium can be image-recorded by scanning the recording medium in a direction intersecting the arrangement direction of the recording elements. In the line method, a conveyance system such as a carriage for scanning a short-sized head in the shuttle method is not required. Also, in the line method, compared with the shuttle method, the movement of the carriage and the complex scanning control of the recording medium are not required, and only the recording medium moves. Therefore, according to the line method, high-speed image recording can be achieved compared with the shuttle method.

[0269] The application of the ink is preferably performed using an inkjet head having a resolution of 300 dpi or more (more preferably 600 dpi or more, and further preferably 800 dpi or more). Here, dpi is an abbreviation for dot per inch, and 1 inch is 2.54 cm.

[0270] From the viewpoint of obtaining a high-definition image, the amount of ink droplets ejected from the nozzles of the inkjet head is preferably 1 pL (picoliter) to 10 pL, and more preferably 1.5 pL to 6 pL.

[0271] <Drying process>

[0272] The image recording step preferably includes a step of drying the applied ink after applying the ink to the image recording substrate (hereinafter also referred to as a "drying step").

[0273] The ink may be dried naturally, but is preferably dried by heating.

[0274] The heating temperature in heat drying is preferably 30°C to 90°C, more preferably 50°C to 80°C.

[0275] Examples of the heat drying method include infrared (IR) drying, warm air drying, and a method using a heating device (eg, a heater, a hot plate, a heating furnace, etc.).

[0276] Heat drying can be performed by heating the ink from at least one of the image recording surface side and the image non-recording surface side of the image recording substrate.

[0277] <Active Energy Ray Irradiation Step>

[0278] The image recording step preferably includes a step of irradiating the applied ink with active energy rays after applying the ink to the image recording substrate (hereinafter also referred to as “active energy ray irradiation step”).

[0279] By irradiating the ink applied to the image recording substrate with active energy rays, a polymerization reaction of the polymerizable compound contained in the ink proceeds, thereby fixing the image and improving the hardness of the image.

[0280] Examples of active energy rays include ultraviolet rays, visible rays, and electron beams. Among them, ultraviolet rays are preferred as active energy rays.

[0281] The peak wavelength of ultraviolet rays is preferably 200 nm to 405 nm, more preferably 220 nm to 390 nm, and further preferably 220 nm to 380 nm.

[0282] The exposure dose of ultraviolet light is preferably 20 mJ / cm 2 ~5J / cm 2 , more preferably 100 mJ / cm 2 ~1,500mJ / cm 2The irradiation conditions and basic irradiation methods can be applied to the irradiation conditions and irradiation methods disclosed in Japanese Patent Publication No. 60-132767. Specifically, the irradiation method is preferably a method of providing light sources on both sides of a nozzle unit of an ink ejection device, scanning the nozzle unit and the light source in a so-called reciprocating manner, or a method of performing the irradiation by using other light sources that are not driven.

[0283] As the light source for ultraviolet irradiation, discharge lamps and laser light sources (gas lasers and solid lasers, etc.) are mainly used. As discharge lamps, for example, mercury lamps, metal halide lamps and ultraviolet fluorescent lamps are widely known. In addition, semiconductor light sources such as UV-LED (ultraviolet light emitting diode) and UV-LD (ultraviolet laser diode) are small, long-life, high-efficiency and low-cost, and are expected to be used as 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 UV-LED.

[0284] <<Lamination process>>

[0285] The lamination step is a step of placing and laminating a lamination substrate containing a polymer containing vinyl chloride as a structural unit on the image recorded in the image recording step.

[0286] <Lamination Base Material>

[0287] Preferred embodiments of the laminating substrate are the same as those of the image recording substrate, and description thereof will be omitted.

[0288] <Lamination method>

[0289] In the lamination process, a laminating substrate is arranged on the image. At this time, other layers such as an adhesive layer can be arranged on the image, and the laminating substrate can be arranged across the other layers. However, in the manufacturing method of the laminate of the present invention, the ink film (i.e., image) obtained by curing the ink has excellent thermal softening properties, so it is preferred not to set other layers. That is, it is preferred to overlap and laminate in a manner that the image and the laminating substrate are in contact. Thus, a laminate having a laminated structure of image recording substrate / image / laminating substrate can be obtained.

[0290] In the lamination process, the image and the lamination substrate are preferably thermally pressed at a temperature of 100° C. or higher. The weighted average glass transition temperature of all polymerizable monomers contained in the ink when they are homopolymers is 0° C. to 100° C. Therefore, by performing thermal pressing at a temperature of 100° C. or higher, the image and the lamination substrate are thermally fused, and the adhesion between the image and the lamination substrate is improved.

[0291] From the viewpoint of suppressing thermal decomposition, the upper limit of the temperature during thermocompression bonding is preferably 200°C, more preferably 160°C, and further preferably 140°C.

[0292] In addition, the temperature during thermocompression bonding refers to the surface temperature of the base material for lamination.

[0293] The pressure during thermocompression bonding is preferably 0.1 MPa to 20 MPa, more preferably 0.5 MPa to 15 MPa.

[0294] The time for thermocompression bonding is, for example, 10 seconds to 500 seconds.

[0295] Thermocompression bonding can be carried out in two stages. For example, the pressure in the first stage can be set to 0.5 MPa to 5 MPa, and the pressure in the second stage is higher than that in the first stage and is set to 6 MPa to 15 MPa.

[0296] The laminate obtained by the method for manufacturing a laminate of the present invention can be used, for example, as a floor material or a wall material for transportation equipment (such as railways, buses, etc.), or a floor material or a wall material for buildings.

[0297] [Inkjet ink]

[0298] The inkjet ink (hereinafter, also simply referred to as "ink") of the present invention contains: a polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 to 21.3 MPa 1 / 2 ; and an N-vinyl compound, and the weighted average of the glass transition temperatures of all the polymerizable monomers contained in the ink as homopolymers is 0 °C to 100 °C, and the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more.

[0299] Inkjet ink refers to ink used for recording images by an inkjet recording method.

[0300] The preferred embodiment of the ink of the present invention is the same as the preferred embodiment of the ink used in the method for manufacturing the above laminate, and the description thereof is omitted.

[0301] The ink of the present invention has excellent solubility in a base material containing a polymer containing vinyl chloride as a structural unit. Therefore, the ink of the present invention is preferably used for being applied to a base material containing a polymer containing vinyl chloride as a structural unit. By being used in a base material containing a polymer containing vinyl chloride as a structural unit, an image with excellent adhesion to the base material can be recorded.

[0302] In the ink of the present invention, the ink film (i.e., the image) formed by curing has excellent thermal softening properties. Therefore, it is preferably used for manufacturing a laminate by disposing a base material for lamination on the image. In particular, as the base material for lamination, a base material containing a polymer containing vinyl chloride as a structural unit is preferably used.

[0303] [Image recording method]

[0304] The image recording method of the present invention preferably includes a step of recording an image by applying ink by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit.

[0305] The preferred mode of the step of recording an image in the image recording method of the present invention is the same as the preferred mode of the image recording step in the manufacturing method of the above laminate, and the description thereof is omitted.

[0306] [Examples]

[0307] Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples as long as it does not depart from its gist.

[0308] [Examples 1 to 13, Comparative Examples 1 to 5]

[0309] [Preparation of Cyan Pigment Dispersion Liquid]

[0310] The following components were mixed and stirred at 2,500 revolutions per minute for 10 minutes using a mixer (L4R manufactured by Silverson Co., Ltd.) to obtain a mixture. Then, the obtained mixture was added to a bead mill disperser DIS PERMAT LS (manufactured by VMA Co., Ltd.), and dispersed at 2,500 revolutions per minute for 6 hours using YTZ balls (manufactured by NIKKATO CORPORATION) with a diameter of 0.65 mm to obtain a cyan pigment dispersion liquid.

[0311] · Cyan pigment: Product name “IRGALITE BLUE GLVO”, manufactured by BASF Corporation... 30% by mass

[0312] · BYK-168: Product name “DISPERSE BYK-168”, manufactured by BYK Co., Ltd... 20% by mass

[0313] · DVE-3: Triethylene glycol divinyl ether, manufactured by BASF Corporation... 50% by mass

[0314] [Preparation of Ink]

[0315] The above cyan pigment dispersion liquid and the components described in Tables 1 and 2 other than the components contained in the cyan pigment dispersion liquid were mixed to the contents described in Tables 1 and 2 to prepare an ink.

[0316] The details of each component in Tables 1 and 2 other than the cyan pigment, dispersant, and DVE-3 are as follows.

[0317] (Polymerizable monomer A)

[0318] ·THFA: Tetrahydrofurfuryl acrylate

[0319] ·EOEOEA: Ethoxydiethylene glycol acrylate

[0320] ·CTFA: Cyclic trimethylolpropane formal acrylate

[0321] (N - vinyl compound)

[0322] ·NVC: N - vinylcaprolactam

[0323] ·Vmox: 5 - methyl - 3 - vinyl - 2 - oxazolinone

[0324] (Other polymerizable compounds)

[0325] ·LA: Lauryl acrylate

[0326] ·IOA: Isooctyl acrylate

[0327] ·EOTMPTA: Trimethylolpropane ethoxylate (EO) triacrylate

[0328] (Polymerization initiator)

[0329] ·ITX: 2 - isopropylthioxanthone

[0330] ·Omni.819: Bis(2,4,6 - trimethylbenzoyl)phenylphosphine oxide (product name “Omni rad 819”, manufactured by IGM Resins B.V.)

[0331] ·Omni.TPO - H: 2,4,6 - trimethylbenzoyldiphenylphosphine oxide (product name “Omnira d TPO - H”, manufactured by IGM Resins B.V.)

[0332] (Polymerization inhibitor)

[0333] ·TEMPOL: 4 - hydroxy - 2,2,6,6 - tetramethylpiperidine - 1 - oxyl

[0334] (Surfactant)

[0335] ·Tegorad2010: Product name “Tegorad2010”, manufactured by Evonik Industries AG, molecular weight 800

[0336] (Resin)

[0337] ·Polyester resin A: Product name “ELITEL UE3380”, manufactured by UNITIKA LTD.

[0338] · Polyester resin B: Product name "ELITEL UE3320", manufactured by UNITIKA LTD.

[0339] · Vinyl chloride - vinyl acetate copolymer: Product name "VINNOL H40 / 43", manufactured by Wacker, Inc.

[0340] <Manufacture of laminate>

[0341] - Image recording process -

[0342] As a substrate for image recording, a polyvinyl chloride substrate (product name "PVC35phr", manufactured by OK AMOTO INDUSTRIES, INC.) was prepared.

[0343] On an inkjet printer (KEGON) manufactured by Afit Co., Ltd., a rubber heater (SR100 manufactured by THREE HIGHCO., LTD.) and an ultraviolet (UV) irradiation device (Vzero manufactured by Integration Technology) were installed, and a modified inkjet printer was prepared. The output of the rubber heater was set to be able to heat the image recording substrate with ink applied thereon to about 60°C. The drying time of the ink during UV irradiation (i.e., the time from when the ink ejected from the inkjet head lands on the image recording substrate until UV is irradiated) was adjusted to 10 seconds. At this time, the adjustment of the drying time of the ink was carried out by adjusting the conveying speed (5 m / min to 25 m / min) and the timing of opening and closing the UV shutter.

[0344] The above ink was ejected from the inkjet head of the modified inkjet printer, and a solid image was recorded on the image recording substrate to obtain an image recording object. The resolution was set to 1200 dpi (dots per inch) × 600 dpi.

[0345] - Laminating process 1 -

[0346] As a substrate for lamination, a polyvinyl chloride substrate (product name "SG800", manufactured by Keienu Trading Company Ltd., thickness 75 μm) was used.

[0347] The substrate for lamination was placed on the image recorded on the image recording substrate. Using a desktop automatic transfer press (product name "AF - 54TEN", manufactured by Asahi Garment Machinery co., ltd), the image and the substrate for lamination were thermally bonded. Thus, a laminate having a laminated structure of image recording substrate / image / substrate for lamination was obtained.

[0348] The temperature in the thermocompression bonding was set at 130°C. The thermocompression bonding was carried out at a pressure of 2 MPa for 300 seconds, and then at a pressure of 10 MPa for 60 seconds.

[0349] Using the evaluation sample of the laminate obtained in the lamination step 1, the peel strength was measured. The evaluation method is as follows.

[0350] [Evaluation]

[0351] The evaluation sample was prepared by the following method.

[0352] An image recording sample of 3.2 cm × 3.2 cm was cut out from the image recording material obtained in the image recording step. And, a laminate base material sample of 3.2 cm × 3.2 cm was cut out from the laminate base material.

[0353] A PET (polyethylene terephthalate) sheet with a thickness of 12 μm was placed on the image recording surface of the image recording sample and in a 1.0 cm × 3.2 cm area including one side of the image recording sample. Then, a laminate base material sample of 3.2 cm × 3.2 cm was overlapped on the entire area of the image recording surface of the image recording sample where the PET sheet was placed (1.0 cm × 3.2 cm area) and the area where the PET sheet was not placed (2.2 cm × 3.2 cm area).

[0354] In this state, the image recording sample and the laminate base material sample were laminated under the same conditions as the above lamination step. By removing the PET sheet from the obtained laminate, an evaluation sample was obtained.

[0355] In the evaluation sample, the image recording sample and the laminate base material sample were bonded in the area where the PET sheet was not placed before the lamination step. On the other hand, in the evaluation sample, the image recording sample and the laminate base material sample were not bonded in the area where the PET sheet was placed before the lamination step.

[0356] Next, in the area where the image recording sample and the laminate base material sample were not bonded, a tensile test of stretching the image recording sample and the laminate base material sample in opposite directions was carried out, and the peel strength was measured. The tensile test was carried out using a tensile testing machine (product name “Autograph AGS-X 5KN”, manufactured by SHIMADZU CORP ORATION). Two evaluation samples were prepared and two tensile tests were carried out. The average value of the two peel strengths was adopted. The evaluation criteria are as follows.

[0357] 5: The peel strength is 7 N / cm or more.

[0358] 4: The peel strength is 3 N / cm or more and less than 7 N / cm.

[0359] 3: The peel strength is 2 N / cm or more and less than 3 N / cm.

[0360] 2: The peel strength is 1 N / cm or more and less than 2 N / cm.

[0361] 1: The peel strength is 0.1 N / cm or more and less than 1 N / cm.

[0362] 0: The peel strength is less than 0.1 N / cm.

[0363] The evaluation results are shown in Table 1 and Table 2.

[0364] In Table 1 and Table 2, for the polymerizable monomer A, N-vinyl compound and other polymerizable compounds, the SP value, molecular weight and glass transition temperature (Tg) are described.

[0365] In Table 1 and Table 2, the "weighted average of Tg" means the weighted average of the glass transition temperatures when all the polymerizable monomers contained in the ink are homopolymers. "N-vinyl compound / polymerizable monomer A" means the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A. "Ratio of polymerizable monomers with a molecular weight of 205 or less" means the ratio of polymerizable monomers with a molecular weight of 205 or less among all the polymerizable compounds contained in the ink. "Ratio of monofunctional polymerizable compounds" means the ratio of monofunctional polymerizable compounds among all the polymerizable compounds contained in the ink.

[0366] [Table 1]

[0367]

[0368] [Table 2]

[0369]

[0370] As shown in Table 1 and Table 2, in Examples 1 to 13, it includes a step of recording an image by imparting an ink by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit; and a step of laminating a laminating substrate containing a polymer containing vinyl chloride as a structural unit on the image, and the ink contains: a polymerizable monomer A having a (meth)acryloyl group with a molecular weight of 215 or less and a solubility parameter of 16.5 MPa 1 / 2 ~21.3 MPa 1 / 2 and an N-vinyl compound, and the weighted average of the glass transition temperatures when all the polymerizable monomers contained in the ink are homopolymers is 0 °C to 100 °C, so it can be seen that the peel strength is high and the adhesion between the substrate and the image is excellent.

[0371] On the other hand, in Comparative Example 1 and Comparative Example 2, the polymerizable monomer A is not contained in the ink, and it can be seen that the adhesion between the substrate and the image is poor.

[0372] In Comparative Example 3, the N-vinyl compound is not contained, and it can be seen that the adhesion between the substrate and the image is poor.

[0373] In Comparative Example 4, the weighted average of the glass transition temperatures when all the polymerizable monomers contained in the ink are homopolymers is less than 0 °C, and it can be seen that the adhesion between the substrate and the image is poor.

[0374] In Comparative Example 5, the weighted average of the glass transition temperatures when all the polymerizable monomers contained in the ink are homopolymers exceeds 100 °C, and it can be seen that the adhesion between the substrate and the image is poor.

[0375] In Example 5, the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more, and compared with Example 6, it can be seen that the peel strength is high.

[0376] In Example 3, the mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.5 or more, and compared with Example 5, it can be seen that the peel strength is high.

[0377] In Example 3, the proportion of the polymerizable monomer having a molecular weight of 205 or less in all the polymerizable compounds contained in the ink is 80% by mass or more, and compared with Example 12, it can be seen that the peel strength is high.

[0378] In Example 3, the proportion of the monofunctional polymerizable compound in all the polymerizable compounds contained in the ink is 90% by mass or more, and compared with Example 11, it can be seen that the peel strength is high.

[0379] In Example 3, the ink contains at least one selected from the group consisting of a vinyl chloride-vinyl acetate copolymer and a polyester resin, and compared with Example 8, it can be seen that the peel strength is high.

[0380] In Example 3, the ink does not contain a surfactant, and compared with Example 7, it can be seen that the peel strength is high.

[0381] [Examples 101 to 105]

[0382] [Preparation of Ink]

[0383] The above cyan pigment dispersion liquid and the components described in Table 4 other than the components contained in the cyan pigment dispersion liquid were mixed into the contents described in Table 4, thereby preparing an ink.

[0384] The details of Resins T1 to T4 in Table 3 are as follows. Resins T1 to T4 were synthesized with reference to the synthesis methods of Examples 8, 9, 25, and 19 of Japanese Patent No. 6861811. The weight-average molecular weights of Resins T1 to T4 were all 10,000.

[0385] Table 3 shows the composition ratios (mass ratios) of the structural units constituting each resin and the SP value.

[0386] [Table 3]

[0387]

[0388] <Manufacture of laminate>

[0389] An image recording material was obtained through the same image recording process as in Example 1.

[0390] -Lamination process 2-

[0391] In lamination process 2, using the obtained image recording material, a laminate was obtained under conditions different from those in the above lamination process 1.

[0392] Specifically, the temperature in thermocompression bonding was set to 130°C, and thermocompression bonding was performed at a pressure of 2 MPa for 300 seconds, and then at a pressure of 4 MPa for 60 seconds.

[0393] Using the evaluation sample of the laminate obtained in lamination process 2, the peel strength 2 was measured. The evaluation method was the same as that for the evaluation sample of the laminate obtained in lamination process 1.

[0394] The evaluation results are shown in Table 4.

[0395] In addition, the ink used in Example 101 was the same as the ink used in Example 2, and only the lamination process in the manufacture of the laminate was different.

[0396] [Table 4]

[0397]

[0398] In Examples 102 to 105, the ink contained Resin T containing at least one group selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms, and it was found that the peel strength was higher compared to Example 101.

[0399] In addition, with respect to the inventions of Japanese Patent Application No. 2022-162750 filed on October 7, 2022 and Japanese Patent Application No. 2023-108852 filed on June 30, 2023, the entirety thereof is incorporated herein by reference. Further, all documents, patent applications, and technical specifications described in this specification are incorporated herein by reference to the same extent as if each of the documents, patent applications, and technical specifications specifically and individually described as being incorporated by reference were set forth herein.

Claims

1. A method for manufacturing a laminate, which comprises: a step of recording an image by applying an ink by an inkjet recording method on an image recording substrate containing a polymer containing vinyl chloride as a structural unit; and a step of laminating by disposing a lamination substrate containing a polymer containing vinyl chloride as a structural unit on the image, The ink contains: a polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 to 21.3 MPa 1 / 2 ; and an N-vinyl compound wherein a weighted average of the glass transition temperatures when all the polymerizable monomers contained in the ink are each a homopolymer is 0°C to 100°C.

2. The method for manufacturing a laminate according to claim 1, wherein a mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more.

3. The method for manufacturing a laminate according to claim 1 or 2, wherein a mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.5 or more.

4. The method for manufacturing a laminate according to claim 1 or 2, wherein a proportion of the polymerizable monomer having a molecular weight of 205 or less in all the polymerizable compounds contained in the ink is 80% by mass or more.

5. The method for manufacturing a laminate according to claim 1 or 2, wherein a proportion of the monofunctional polymerizable compound in all the polymerizable compounds contained in the ink is 90% by mass or more.

6. The method for manufacturing a laminate according to claim 1 or 2, wherein the polymerizable monomer A contains at least one selected from the group consisting of cyclic trimethylolpropane formal acrylate and ethoxydiethylene glycol acrylate.

7. The method for manufacturing a laminate according to claim 1 or 2, wherein the ink further contains at least one selected from the group consisting of vinyl chloride-vinyl acetate copolymer and polyester resin.

8. The method for manufacturing a laminate according to claim 1 or 2, wherein the ink further contains a resin T containing at least one group selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

9. The method for manufacturing a laminate according to claim 8, wherein The resin T contains a structural unit derived from a polymerizable monomer having a solubility parameter of 16.5 MPa 1 / 2 to 24.0 MPa 1 / 2 .

10. The method for manufacturing a laminate according to claim 1 or 2, wherein the ink does not contain a surfactant, or a content of the surfactant is less than 0.1% by mass relative to a total amount of the ink.

11. The method for manufacturing a laminate according to claim 1 or 2, wherein in the lamination step, the image and the lamination substrate are thermocompression bonded at a temperature of 100°C or higher.

12. The method for manufacturing a laminate according to claim 1 or 2, wherein in the lamination step, they are overlapped and laminated in such a manner that the image and the lamination substrate are in contact with each other.

13. An inkjet ink, which comprises: A polymerizable monomer A having a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa 1 / 2 to 21.3 MPa 1 / 2 ; and an N-vinyl compound, a weighted average of the glass transition temperatures when all the polymerizable monomers contained in the inkjet ink are each a homopolymer is 0°C to 100°C, a mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.35 or more.

14. The inkjet ink according to claim 13, wherein The mass ratio of the content of the N-vinyl compound to the content of the polymerizable monomer A is 0.5 or more.

15. The inkjet ink according to claim 13, wherein the proportion of the polymerizable monomer having a molecular weight of 205 or less in all the polymerizable compounds contained in the inkjet ink is 80% by mass or more.

16. The inkjet ink according to claim 13, wherein the proportion of the monofunctional polymerizable compound in all the polymerizable compounds contained in the inkjet ink is 90% by mass or more.

17. The inkjet ink according to claim 13, wherein the polymerizable monomer A contains at least one selected from the group consisting of cyclic trimethylolpropane formal acrylate and ethoxydiethylene glycol acrylate.

18. The inkjet ink according to claim 13, wherein the inkjet ink further contains at least one selected from the group consisting of a vinyl chloride-vinyl acetate copolymer and a polyester resin.

19. The inkjet ink according to claim 13, wherein the inkjet ink further contains a resin T containing at least one group selected from the group consisting of a fluorinated hydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

20. The inkjet ink according to claim 19, wherein The resin T contains a structural unit derived from a polymerizable monomer having a solubility parameter of 16.5 MPa 1 / 2 to 24.0 MPa 1 / 2 .

21. The inkjet ink according to claim 13, wherein the inkjet ink does not contain a surfactant, or the content of the surfactant is less than 0.1% by mass relative to the total amount of the inkjet ink.

22. An image recording method, which comprises: a step of recording an image by applying the inkjet ink according to any one of claims 13 to 21 by an inkjet recording method onto an image recording substrate containing a polymer containing vinyl chloride as a structural unit.

Images