Inkjet ink, image recording method, and laminate manufacturing method

Abstract

To provide inkjet ink which is excellent in laminate strength in a laminate manufactured by laminating an image recorded material containing a base material for image recording containing a polymer containing vinyl chloride as a constitutional unit and an image, and a laminate base material containing a polymer containing vinyl chloride as a constitutional unit, so that the image in the image recorded material and the laminate base material face each other, and is excellent in blocking resistance of the image in the image recorded material.SOLUTION: There are provided inkjet ink which contains a polymerizable monomer, and an α-aminoketone type photopolymerization initiator having a molecular weight of 600 or more, wherein a weighted average value of a glass transition temperature of a homopolymer of the polymerizable monomer is 0°C to 50°C; and application of the same.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Various studies have been conducted on image recording using inkjet inks.

[0003] For example, Patent Document 1 discloses an ultraviolet-curable inkjet ink (i.e., an ultraviolet-curable inkjet ink) that is excellent in ejection properties, curing properties, and flexibility, and that is an inkjet ink comprising at least (A) dipropylene glycol diacrylate, (B) N-vinylcaprolactam, and (C) a monofunctional acrylic monomer having a Tg of less than 20°C, wherein the total amount of (A), (B), and (C) is 60 to 90% by weight of the total ink components, and the amount of the monofunctional acrylic monomer having a Tg of 20°C or higher is less than 10% by weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-122063 Summary of the Invention [Problem to be solved by the invention]

[0005] A laminate may be produced by laminating an image recorded by applying an inkjet ink to an image recording substrate containing a polymer (e.g., polyvinyl chloride) containing vinyl chloride as a structural unit, and a laminate substrate containing a polymer (e.g., polyvinyl chloride) containing vinyl chloride as a structural unit, such that the image on the image recorded faces the laminate substrate. In this case, it may be necessary to improve the lamination strength between the image and the laminate substrate. On the other hand, there are cases where blocking resistance (that is, the ability to suppress blocking) of images in image recordings is required. In general, when the lamination strength between an image and a substrate for lamination is improved, the blocking resistance of the image tends to be reduced, and when the blocking resistance of the image is improved, the lamination strength of the image tends to be reduced.

[0006] The present disclosure has been made in consideration of the above circumstances, and a problem that one embodiment of the present disclosure aims to solve is to provide an inkjet ink, an image recording method, and a method for manufacturing a laminated body that are capable of recording an image that has excellent lamination strength and blocking resistance. [Means for solving the problem]

[0007] The present disclosure includes the following aspects. <1> a polymerizable monomer; an α-aminoketone photopolymerization initiator having a molecular weight of 600 or more; Contains The weighted average glass transition temperature of the homopolymer of the polymerizable monomer is 0°C to 50°C. Inkjet ink. <2> Further, an acylphosphine oxide type photopolymerization initiator is contained, the mass ratio of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more to the acylphosphine oxide photopolymerization initiator is 0.010 to 1.5; <1> The inkjet ink according to claim 1. <3> Further, it contains a sensitizing dye, the mass ratio of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more to the sensitizing dye is 0.010 to 2.0; <1> or <2> The inkjet ink according to claim 1. <4> The polymerizable monomer comprises an N-vinyl compound. <1> ~ <3> 10. The ink-jet ink according to any one of the preceding items. <5> the mass ratio of the amount of the N-vinyl compound to the total amount of polymerizable monomers is 0.30 or more; <4> The inkjet ink according to claim 1. <6> The polymerizable monomers include a monomer M1 having a glass transition temperature of 90°C or higher when made into a homopolymer, and a monomer M2 having a glass transition temperature of 30°C or lower when made into a homopolymer, the content of the monomer M1 relative to the total amount of the inkjet ink is 20% by mass to 50% by mass, and the content of the monomer M2 relative to the total amount of the inkjet ink is 35% by mass to 65% by mass; <1> ~ <5> 10. The ink-jet ink according to any one of the preceding items. <7> The polymerizable monomer has a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa. 1 / 2 ~21.5MPa 1 / 2 a monomer A, the mass ratio of the amount of monomer A to the total amount of polymerizable monomers is 0.50 or more; <1> ~ <6> 10. The ink-jet ink according to any one of the preceding items. <8> The polymerizable monomer includes a compound having a molecular weight of 215 or less, the mass ratio of the amount of the compound having a molecular weight of 215 or less to the total amount of the polymerizable monomers is 0.80 or more; <1> ~ <7> 10. The ink-jet ink according to any one of the preceding items. <9> The polymerizable monomer includes a monofunctional monomer, the mass ratio of the amount of the monofunctional monomer to the total amount of the polymerizable monomers is 0.90 or more; <1> ~ <8> 10. The ink-jet ink according to any one of the preceding items. <10> The polymerizable monomer includes a compound having two or more (meth)acryloyl groups, the mass ratio of the amount of the compound having two or more (meth)acryloyl groups to the total amount of polymerizable monomers is more than 0 and 0.10 or less; <1> ~ <9> 10. The ink-jet ink according to any one of the preceding items. <11> The polymerizable monomer is a compound having two or more (meth)acryloyl groups, and includes a monomer B which is a compound other than the monomer A, the mass ratio of the amount of monomer B to the total amount of polymerizable monomers is more than 0 and 0.10 or less; <7> or <8> The inkjet ink according to claim 1. <12> Further, the composition contains a resin T containing at least one selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms. <1> ~ <11> 10. The ink-jet ink according to any one of the preceding items. <13> Resin T contains structural units derived from hydroxyethyl methacrylate, <12> The inkjet ink according to claim 1. <14> On an image recording substrate containing a polymer containing vinyl chloride as a structural unit, <1> ~ <13> 1. An image recording method comprising a step of applying the inkjet ink according to any one of the above items by an inkjet recording method to record an image. <15> <14> obtaining an image recording material comprising an image recording substrate and an image by the image recording method described in 1. a step of laminating an image recorded material and a laminate substrate containing a polymer containing vinyl chloride as a constituent unit, with the image on the image recorded material and the laminate substrate facing each other to obtain a laminate; A method for manufacturing a laminate, comprising: [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, there are provided an inkjet ink, an image recording method, and a method for manufacturing a laminated body, which are capable of recording an image having excellent lamination strength and excellent blocking resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] In this specification, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0010] In this specification, the amount of each component in a composition means the total amount of the multiple substances present in the composition, unless otherwise specified, when multiple substances corresponding to each component are present in the composition. As used herein, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0011] In this specification, the term "image" generally refers to a film (that is, an ink film) formed by applying ink, and the term "image recording" refers to the formation of an image (that is, an ink film). In this specification, the concept of "image" also includes a solid image.

[0012] In this specification, the term "(meth)acrylate" encompasses both acrylate and methacrylate, and the term "(meth)acrylic" encompasses both acrylic and methacrylic.

[0013] [Inkjet ink] The inkjet ink (hereinafter also simply referred to as "ink") of the present disclosure is a polymerizable monomer; an α-aminoketone photopolymerization initiator having a molecular weight of 600 or more; Contains The weighted average glass transition temperature of the homopolymer of the polymerizable monomer is 0°C to 50°C. It's ink.

[0014] As mentioned above, generally, when the lamination strength of an image is improved, the blocking resistance of the image tends to decrease, and when the blocking of the image is suppressed (i.e., when the blocking resistance is improved), the lamination strength of the image tends to be insufficient.

[0015] In the present disclosure, the lamination strength of an image means the lamination strength between an image and a lamination substrate when a laminate is produced by laminating an image recorded by applying ink to an image recording substrate (hereinafter also simply referred to as "image recording substrate") containing a polymer containing vinyl chloride as a constituent unit (e.g., polyvinyl chloride) and a lamination substrate containing a polymer containing vinyl chloride as a constituent unit (e.g., polyvinyl chloride) in an arrangement where the image in the image recorded and the lamination substrate face each other.

[0016] In the present disclosure, blocking refers to a phenomenon in which, when a substrate (for example, an image recording substrate) is placed on top of an image recorded on an image recording substrate, the image and the substrate placed on top of the image adhere to each other and become difficult to peel off. In the present disclosure, blocking resistance refers to the ability to inhibit blocking.

[0017] In response to the above-mentioned problems, the ink of the present disclosure makes it possible to record images that have excellent lamination strength and blocking resistance. The reason why such an effect is achieved is presumed to be as follows. In the ink of the present disclosure, a weighted average value of the glass transition temperatures (Tg) of the homopolymers of the polymerizable monomers contained therein (hereinafter simply referred to as "weighted average value of Tg") of 0°C or higher is thought to contribute to suppressing stickiness of the image, and as a result, contribute to improving the blocking resistance of the image. Also, in the ink of the present disclosure, a weighted average value of Tg of 50°C or lower is thought to contribute to improving the heat softening properties of the image, and as a result, contribute to improving the lamination strength of the image. However, it has been found that the blocking resistance of images may be insufficient even when the weighted average Tg is between 0° C. and 50° C. This is thought to be due to insufficient curing near the surface of the ink film (i.e., the interface with air). Therefore, when the weighted average value of Tg is 0°C to 50°C, blocking is suppressed (i.e., blocking resistance is improved) by including an α-aminoketone photopolymerization initiator with a molecular weight of 600 or more in the ink. This is thought to be because the α-aminoketone photopolymerization initiator with a molecular weight of 600 or more contributes particularly to the curing properties near the surface of the ink film.

[0018] The inks of the present disclosure are described in more detail below.

[0019] <Polymerizable monomer> The inks of the present disclosure contain at least one polymerizable monomer.

[0020] In the present disclosure, a polymerizable monomer refers to a compound that has a polymerizable group and has a molecular weight of 1,000 or less. Here, the molecular weight is calculated based on the type and number of atoms that constitute the compound.

[0021] The polymerizable group in the polymerizable monomer is preferably an ethylenically unsaturated group (that is, a group containing an ethylenic double bond), and more preferably a (meth)acryloyl group, an allyl group, a styryl group, or a vinyl group.

[0022] (weighted average Tg) In the ink of the present disclosure, the weighted average value of the glass transition temperatures (weighted average value of Tg) of the homopolymers of the polymerizable monomers is 0°C to 50°C.

[0023] In the present disclosure, the weighted average value of the glass transition temperatures of homopolymers of polymerizable monomers (weighted average value of Tg) refers to the weighted average value of the glass transition temperatures when all types of polymerizable monomers contained in the ink of the present disclosure are treated as homopolymers. For example, when the ink of the present disclosure contains two or more polymerizable monomers, the weighted average Tg value means the weighted average of the glass transition temperatures when each of the two or more polymerizable monomers is treated as a homopolymer. When the ink of the present disclosure contains only one type of polymerizable monomer, the weighted average value of Tg means the glass transition temperature itself when that one type of polymerizable monomer is treated as a homopolymer.

[0024] The weighted average value of Tg in the ink of the present disclosure means a value measured as follows.

[0025] For each of all (i.e., all types of) polymerizable monomers contained in the ink, a homopolymer having a weight-average molecular weight of 10,000 to 20,000 is produced, and the glass transition temperature of the produced homopolymer is measured according to the method described in JIS K7121:2012.

[0026] In the present disclosure, the glass transition temperature is measured using a differential scanning calorimeter, for example, a product named "DSC-60" manufactured by Shimadzu Corporation. In this disclosure, the weight-average molecular weight is measured using gel permeation chromatography (GPC). For example, an HLC-8220GPC (manufactured by Tosoh Corporation) is used as the GPC, three TSKgel Super Multipore HZ-H columns (manufactured by Tosoh Corporation, 4.6 mm ID x 15 cm) are used as the columns, and THF (tetrahydrofuran) is used as the eluent. The conditions are a sample concentration of 0.45% by mass, a flow rate of 0.35 ml / min, a sample injection volume of 10 μl, a measurement temperature of 40°C, and detection using a refractive index (RI) detector. A calibration curve is prepared using eight standard samples of "TSK Standard Polystyrene" (manufactured by Tosoh Corporation) with product names of "F-40," "F-20," "F-4," "F-1," "A-5000," "A-2500," "A-1000," and "n-propylbenzene."

[0027] The glass transition temperature of a homopolymer varies depending on the weight average molecular weight of the homopolymer, but when the weight average molecular weight is 10,000 to 20,000, the variation is so small that it can be ignored.

[0028] The weighted average value of Tg 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 when it is treated as a homopolymer, and C i represents the content (mass %) of the i-th polymerizable monomer relative to the total amount of ink.

[0029] Weighted average value of glass transition temperature = ΣT i C i / ΣC i

[0030] As described above, when the weighted average value of Tg is 0° C. or more, the blocking resistance of the image is improved. From the viewpoint of further improving the blocking resistance of the image, the weighted average value of Tg is preferably 5°C or higher, more preferably 10°C or higher, and even more preferably 15°C or higher.

[0031] Furthermore, as described above, when the weighted average value of Tg is 50° C. or less, the lamination strength of the image is improved. From the viewpoint of further improving the lamination strength of the image, the weighted average value of Tg is preferably 45°C or less, more preferably 40°C or less.

[0032] From the viewpoint of more effectively achieving both lamination strength and blocking resistance, the polymerizable monomer in the ink of the present disclosure preferably includes a monomer M1 having a glass transition temperature of 90°C or higher when made into a homopolymer, and a monomer M2 having a glass transition temperature of 30°C or lower when made into a homopolymer. When the ink of the present disclosure contains the monomer M1, the content of the monomer M1 relative to the total amount of the ink is preferably 20% by mass to 50% by mass. When the ink of the present disclosure contains the monomer M2, the content of the monomer M2 relative to the total amount of the ink is preferably 35% by mass to 65% by mass.

[0033] (Functionality of polymerizable monomer) The polymerizable monomer may include a monofunctional monomer, a difunctional or higher functional monomer, or both. Here, the monofunctional monomer means a polymerizable monomer having only one polymerizable group, and the bifunctional or higher functional monomer means a polymerizable monomer having two or more polymerizable groups. That is, an n-functional monomer in the present disclosure is a polymerizable monomer having n polymerizable groups.

[0034] From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the amount of monofunctional monomer to the total amount of polymerizable monomer (hereinafter also referred to as the content mass ratio [monofunctional monomer / total polymerizable monomer]) is preferably 0.80 or more, more preferably 0.85 or more, even more preferably 0.90 or more, and even more preferably 0.95 or more. The mass ratio of the content [monofunctional monomer / total polymerizable monomers] may be 1 or less.

[0035] The content of the polymerizable monomer relative to the total amount of the ink of the present disclosure is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and still more preferably 80% by mass or more.

[0036] The total content of the monofunctional monomer and the difunctional monomer relative to the total amount of the ink of the present disclosure is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and still more preferably 80% by mass or more.

[0037] Furthermore, the content of the monofunctional monomer relative to the total amount of the ink of the present disclosure is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and still more preferably 80% by mass or more.

[0038] (mass ratio of monomers with molecular weights of 215 or less to total polymerizable monomers) From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the amount of polymerizable monomers having a molecular weight of 215 or less to the total amount of polymerizable monomers contained in the ink (hereinafter also referred to as the content mass ratio [monomers having a molecular weight of 215 or less / total polymerizable monomers]) is preferably 0.80 or more, more preferably 0.85 or more, even more preferably 0.90 or more, and even more preferably 0.95 or more. The mass ratio of the content [monomers having a molecular weight of 215 or less / total polymerizable monomers] may be 1 or less.

[0039] (N-vinyl compounds) From the viewpoint of further improving laminate strength, the polymerizable monomer in the ink of the present disclosure preferably contains at least one N-vinyl compound.

[0040] The ink comprises at least one N-vinyl compound. N-vinyl compounds are compounds in which a vinyl group is bonded to a nitrogen atom. N-vinyl compounds have high solubility in image recording substrates, and therefore contribute to the adhesion between the image recording substrate and the image.

[0041] Examples of N-vinyl compounds include N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylcarbazole, N-vinylimidazole, N-vinylphthalimide, N-vinylacetamide, N-vinylformamide, and 5-methyl-3-vinyl-2-oxazolidinone.

[0042] Among these, from the viewpoint of high solubility in the image recording substrate and improving adhesion between the image recording substrate and the image, the N-vinyl compound is preferably at least one selected from the group consisting of N-vinylcaprolactam and 5-methyl-3-vinyl-2-oxazolidinone.

[0043] 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 even more preferably 20% by mass to 30% by mass, relative to the total amount of the ink.

[0044] From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the amount of N-vinyl compound to the total amount of polymerizable monomers contained in the ink (hereinafter also referred to as the content mass ratio [N-vinyl compound / total polymerizable monomers]) is preferably 0.15 or more, preferably 0.20 or more, and more preferably 0.30 or more. The content mass ratio [N-vinyl compound / total polymerizable monomers] may be 1, but is preferably less than 1, more preferably 0.80 or less, and even more preferably 0.60 or less.

[0045] (Monomer A) The polymerizable monomer in the ink of the present disclosure preferably contains at least one type of monomer A, from the viewpoint of further improving laminate strength. Monomer A has a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa. 1 / 2 ~21.5MPa 1 / 2 It is a polymerizable monomer.

[0046] The molecular weight of monomer A is 215 or less, preferably 205 or less, and more preferably 200 or less. A molecular weight of 215 or less for monomer A indicates a relatively low molecular weight, and by making it 215 or less, the ink is more easily dissolved in the image recording substrate, which results in improved adhesion between the image recording substrate and the ink film, and improved lamination strength. Furthermore, when the molecular weight of the monomer A is 215 or less, the distance between crosslinking points becomes short, and the density of the ink film increases, thereby improving the laminate strength.

[0047] The lower limit of the molecular weight of the monomer A is not particularly limited, but is 100, for example. The molecular weight is calculated based on the type and number of atoms that make up the compound.

[0048] The solubility parameter (hereinafter also referred to as SP value) of Monomer A is 16.5 MPa 1 / 2 ~21.5MPa 1 / 2 and 18 MPa 1 / 2 ~19.5MPa 1 / 2 It is preferable that: The SP value of Monomer A is 16.5 MPa. 1 / 2 ~21.5MPa 1 / 2 This allows the ink to have high affinity for the image-recording substrate and excellent solubility. Polymerization proceeds in a state where the ink is partially dissolved in the image-recording substrate, improving adhesion between the image-recording substrate and the image, and as a result, improving laminate strength.

[0049] In this disclosure, the SP value of monomer A refers to the Hansen solubility parameter, which is a solubility parameter introduced by Hildebrand, divided into three components: a dispersion term δd, a polar term δp, and a hydrogen bonding term δh, and expressed in a three-dimensional space.

[0050] The SP value δ of the monomer A is a value calculated using the following formula A. SP value (δ) [MPa 1 / 2 ]=(δd 2 +δp 2 +δh 2 ) 1 / 2 …(A)

[0051] The dispersion term δd, polar term δp, and hydrogen bond term δh are calculated using HSPiP (version 4.1.07) software.

[0052] 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 has high activity toward polymerizable monomers having a (meth)acryloyl group, and the polymerization reaction proceeds quickly. Because Monomer A has a (meth)acryloyl group, when it coexists with the N-vinyl compound in the ink, the polymerization reaction proceeds quickly and the ink has excellent curing properties.

[0053] The number of (meth)acryloyl groups contained in Monomer A may be only one or may be two or more, but is preferably only one (i.e., Monomer A is preferably a monofunctional (meth)acrylate).

[0054] Examples of the monomer A include the following compounds. Tetrahydrofurfuryl acrylate (SP value: 18.8 MPa 1 / 2 ) Cyclic trimethylolpropane formal acrylate (SP value: 19.0 MPa) 1 / 2 ) Ethoxydiethylene glycol acrylate (SP value: 18.2 MPa 1 / 2 ) Cyclohexyl acrylate (SP value: 17.9 MPa 1 / 2 ) Isobornyl acrylate (SP value: 17.1 MPa) 1 / 2 ) Phenoxyethyl acrylate (SP value: 19.44 MPa 1 / 2 ) N,N-dimethylacrylamide (SP value: 21.4 MPa) 1 / 2 ) 4-tert-butylcyclohexyl acrylate (SP value: 16.7 MPa) 1 / 2 ) 3,3,5-trimethylcyclohexyl acrylate (SP value: 16.7 MPa 1 / 2 ) 4-Hydroxybutyl acrylate (SP value: 21.0 MPa 1 / 2 ) 2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate (SP value: 18.2 MPa) 1 / 2 ) Benzyl acrylate (SP value: 19.0 MPa 1 / 2 ) (3-ethyloxetan-3-yl)methyl acrylate (SP value: 18.6 MPa) 1 / 2 ) 2-Oxotetrahydrofuran-3-yl acrylate (SP value: 21.2 MPa) 1 / 2 )

[0055] Among these, from the viewpoint of improving adhesion to the image recording substrate and adhesion to the laminating substrate, it is preferable that the monomer A contains at least one selected from the group consisting of tetrahydrofurfuryl acrylate, cyclic trimethylolpropane formal acrylate, and ethoxydiethylene glycol acrylate, and it is preferable that the monomer A contains at least one selected from the group consisting of tetrahydrofurfuryl acrylate and ethoxydiethylene glycol acrylate. It is more preferable that the compound contains at least one selected from the group:

[0056] The content of Monomer A is preferably 30% by mass to 75% by mass, more preferably 40% by mass to 70% by mass, and even more preferably 44% by mass to 63% by mass, relative to the total amount of the ink.

[0057] From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the amount of monomer A to the total amount of polymerizable monomers contained in the ink (hereinafter also referred to as the content mass ratio [monomer A / total polymerizable monomers]) is preferably 0.25 or more, more preferably 0.30 or more, even more preferably 0.40 or more, and even more preferably 0.50 or more. The content mass ratio [monomer A / total polymerizable monomers] may be 1 or less.

[0058] (Other polymerizable monomers) The ink of the present disclosure may contain, as the other polymerizable monomer, a polymerizable monomer other than the monomer A and the N-vinyl compound. The polymerizable group of the other polymerizable monomer is preferably a radical polymerizable group, more preferably a photoradical polymerizable group, and even more preferably an ethylenically unsaturated group. Examples of the other polymerizable monomer include (meth)acrylate compounds, (meth)acrylamide compounds, vinyl ether compounds, allyl compounds, and unsaturated carboxylic acids.

[0059] From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the total amount of monomer A and N-vinyl compound to the total amount of polymerizable monomers contained in the ink (i.e., content mass ratio [(monomer A + N-vinyl compound) / total polymerizable monomers]) is preferably 0.50 or more, more preferably 0.60 or more, even more preferably 0.70 or more, and still more preferably 0.80 or more. The content mass ratio [(monomer A+N-vinyl compound) / total polymerizable monomers] may be 1 or less.

[0060] -Bifunctional or higher (meth)acrylates- From the viewpoint of further improving laminate strength through crosslinking, the polymerizable monomer in the ink of the present disclosure preferably contains a compound having two or more (meth)acryloyl groups (that is, a bifunctional or higher functional (meth)acrylate).

[0061] As the compound having two or more (meth)acryloyl groups (that is, bifunctional or higher (meth)acrylate), a compound having two (meth)acryloyl groups (that is, bifunctional (meth)acrylate) is particularly preferred.

[0062] Furthermore, examples of the bifunctional or higher functional (meth)acrylate include Monomer B, which is a compound having two or more (meth)acryloyl groups and is a compound other than Monomer A. Monomer B is preferably a compound having two (meth)acryloyl groups (that is, a difunctional (meth)acrylate).

[0063] Preferred embodiments of the difunctional or higher functional (meth)acrylate include difunctional (meth)acrylates (e.g., monomer B), such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. , 3-methyl-1,5-pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, heptanediol 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, tricyclodecane dimethanol di(meth)acrylate, and the like.

[0064] From the viewpoint of further improving the laminate strength, when the ink of the present disclosure contains a difunctional or higher functional (meth)acrylate (e.g., monomer B), the content of the difunctional or higher functional (meth)acrylate is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 2.5% by mass or less, relative to the total amount of the ink. From the viewpoint of further improving the laminate strength, the content of the bifunctional or higher (meth)acrylate is preferably more than 0 mass%, more preferably 0.01 mass% or more, even more preferably 0.05 mass% or more, and still more preferably 0.1 mass% or more.

[0065] From the viewpoint of further improving the laminate strength, in the ink of the present disclosure, the mass ratio of the amount of difunctional or higher (meth)acrylate (e.g., monomer B) to the total amount of polymerizable monomers contained in the ink (hereinafter also referred to as the content mass ratio [difunctional or higher (meth)acrylate (e.g., monomer B) / total polymerizable monomers]) is preferably 0.20 or less, more preferably 0.10 or less, and even more preferably 0.05 or less. From the viewpoint of further improving the laminate strength, the content mass ratio [difunctional or higher (meth)acrylate (e.g., monomer B) / total polymerizable monomers] is greater than 0, preferably 0.0001 or more, more preferably 0.0005 or more, and even more preferably 0.001 or more.

[0066] In one preferred embodiment of the ink of the present disclosure, the polymerizable monomer contains a monofunctional monomer and a di- or higher functional (meth)acrylate; The content mass ratio [monofunctional monomer / total polymerizable monomer] is 0.90 or more, The content mass ratio [difunctional or higher (meth)acrylates / total polymerizable monomers] is greater than 0 and 0.10 or less, The following aspects can be mentioned.

[0067] Another preferred embodiment of the ink of the present disclosure is the polymerizable monomers include monomer A and monomer B; The content mass ratio [monomer A / total polymerizable monomers] is 0.50 or more, the content mass ratio [monomer B / total polymerizable monomers] is greater than 0 and not greater than 0.20 (preferably greater than 0 and not greater than 0.10); The following aspects can be mentioned.

[0068] <α-aminoketone photoinitiator with a molecular weight of 600 or more> The ink of the present disclosure contains at least one α-aminoketone photopolymerization initiator having a molecular weight of 600 or more. This improves the hardening property near the surface of the ink film (that is, the interface with air), resulting in improved blocking resistance of the image.

[0069] In the present disclosure, an α-aminoketone photopolymerization initiator having a molecular weight of 600 or more is a photopolymerization initiator containing an α-aminoketone structure and having a molecular weight of 600 or more. The α-aminoketone structure refers to the following structure (AK), which is a structure in which an amino group is bonded to the carbon atom at the α-position of a ketone group: In structure (AK), * indicates the bonding position.

[0070] [ka]

[0071] The α-aminoketone photopolymerization initiator having a molecular weight of 600 or more preferably further contains a polyalkyleneoxy group, more preferably contains a polyalkyleneoxy group formed by linking alkyleneoxy groups having 2 to 4 carbon atoms, and further preferably contains at least one of a polyethyleneoxy group and a polypropyleneoxy group.

[0072] The α-aminoketone photopolymerization initiator having a molecular weight of 600 or more preferably further contains an aromatic ring structure.

[0073] The molecular weight of the α-aminoketone type photopolymerization initiator having a molecular weight of 600 or more is preferably 800 or more. The molecular weight of the α-aminoketone type photopolymerization initiator having a molecular weight of 600 or more is preferably 1,800 or less.

[0074] For the structure of α-aminoketone photopolymerization initiators with a molecular weight of 600 or more, reference can be made to publicly known documents such as JP 2009-197066 A, WO 2017 / 195428 A, and JP 2007-525573 A.

[0075] The α-aminoketone photopolymerization initiator having a molecular weight of 600 or more is, for example, a compound represented by the following formula (AK1).

[0076] [ka]

[0077] In formula (AK1), Ar is —N(R 5 )(R 6 ), or -C(=O)-N(R 5 )(R 6 ) is a phenyl group substituted with R 1 and R 2 are each independently an alkyl group having 1 to 8 carbon atoms. 1 and R 2 may be bonded to each other to form an alkylene group having 2 to 9 carbon atoms. 3 and R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy-substituted alkyl group having 2 to 4 carbon atoms, or an alkenyl group having 3 to 5 carbon atoms. 3 and R 4 may be bonded to each other to form an alkylene group having 3 to 7 carbon atoms, and the alkylene group may have an -O- or -N(R 7 )-, where R 7 represents an alkyl group having 1 to 4 carbon atoms. R 5 and R 6are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy-substituted alkyl group having 2 to 4 carbon atoms, or an alkenyl group having 3 to 5 carbon atoms. 5 and R 6 may be bonded to each other to form an alkylene group having 3 to 7 carbon atoms, and the alkylene group may have -O- or -N(R 11 )-, where R 11 is a hydrogen atom, a hydroxyalkyl group having 1 to 4 carbon atoms, or a group represented by the following formula (R11A).

[0078] [ka]

[0079] In formula (R11A), R 8 represents an alkylene group having 2 to 4 carbon atoms, and R 9 represents a hydrogen atom, a phenyl group, or an alkyl group having 1 to 4 carbon atoms; R 10 represents a hydrogen atom or a methyl group, and m represents an integer of 0 to 20.

[0080] The content of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more relative to the total amount of the ink of the present disclosure is preferably 0.010% by mass to 8.0% by mass, preferably 0.1% by mass to 5.0% by mass, more preferably 0.5% by mass to 4.0% by mass, and even more preferably 1.0% by mass to 3.5% by mass.

[0081] <α-aminoketone photoinitiator with a molecular weight of less than 600> The ink of the present disclosure may contain at least one α-aminoketone type photopolymerization initiator having a molecular weight of less than 600. However, when the ink of the present disclosure contains an α-aminoketone photopolymerization initiator having a molecular weight of less than 600, the mass ratio of the content of the α-aminoketone photopolymerization initiator having a molecular weight of less than 600 to the content of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more is preferably less than 1, more preferably less than 0.5, even more preferably less than 0.1, and even more preferably less than 0.01.

[0082] <Acylphosphine oxide photopolymerization initiator> The ink of the present disclosure preferably contains at least one acylphosphine oxide type photopolymerization initiator. This further improves the lamination strength of the image.

[0083] The mass ratio of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more to the acylphosphine oxide photopolymerization initiator (hereinafter also referred to as the mass ratio [α-aminoketone initiator having a molecular weight of 600 or more / acylphosphine oxide initiator]) is preferably 0.005 to 2.0, more preferably 0.010 to 1.5, even more preferably 0.020 to 1.5, and still more preferably 0.3 to 1.5. When the content mass ratio [α-aminoketone type initiator having a molecular weight of 600 or more / acylphosphine oxide type initiator] is 0.005 or more, the blocking resistance of the image is further improved. When the content mass ratio [α-aminoketone type initiator having a molecular weight of 600 or more / acylphosphine oxide type initiator] is 2.0 or less, the lamination strength of the image is further improved.

[0084] Examples of the acylphosphine oxide type photopolymerization initiator include monoacylphosphine oxide compounds and bisacylphosphine oxide compounds, with bisacylphosphine oxide compounds being preferred.

[0085] Examples of the monoacylphosphine oxide compound include isobutyryldiphenylphosphine oxide, 2-ethylhexanoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, o-toluyldiphenylphosphine oxide, pt-butylbenzoyldiphenylphosphine oxide, 3-pyridylcarbonyldiphenylphosphine oxide, acryloyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid vinyl ester, acryloyldiphenylphosphine oxide, benzo ... Examples of the diphenylphosphine oxide include dipoylbisdiphenylphosphine oxide, pivaloyldiphenylphosphine oxide, p-toluyldiphenylphosphine oxide, 4-(t-butyl)benzoyldiphenylphosphine oxide, terephthaloylbisdiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, versatoyldiphenylphosphine oxide, 2-methyl-2-ethylhexanoyldiphenylphosphine oxide, 1-methyl-cyclohexanoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid methyl ester, and pivaloylphenylphosphinic acid isopropyl ester.

[0086] Examples of the bisacylphosphine oxide compound include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-ethoxyphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2-naphthylphosphine oxide, and bis(2,6-dichlorobenzoyl). 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.

[0087] Among them, acylphosphine oxide compounds are Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (product name "Omnirad 819", manufactured by IGM Resins BV), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product name "Omnirad TPO-H", manufactured by IGM Resins BV), and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide (product name "Omnirad TPO-L", manufactured by IGM Resins BV) It is preferable that the composition contains at least one selected from the group consisting of:

[0088] <Other photopolymerization initiators> The ink of the present disclosure may contain a photopolymerization initiator other than the α-aminoketone type photopolymerization initiator and the acylphosphine oxide type photopolymerization initiator.

[0089] Examples of other photopolymerization initiators include alkylphenone compounds other than α-aminoketone-type photopolymerization initiators, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds.

[0090] <Sensitizing dye> The ink of the present disclosure preferably contains at least one sensitizing dye. This further improves the lamination strength of the image.

[0091] The content mass ratio of the sensitizing dye to the acylphosphine oxide type photopolymerization initiator (hereinafter also referred to as the content mass ratio [sensitizing dye / acylphosphine oxide type initiator]) is preferably 0.005 to 5.0, more preferably 0.010 to 3.0, even more preferably 0.050 to 2.0, and still more preferably 0.1 to 2.0.

[0092] As the sensitizing dye, a thio compound is preferred, and a thioxanthone compound is more preferred. Examples of thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone (preferably 2,4-diethylthioxanthen-9-one (DETX)), 2,4-dimethylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxy)-2-methyl ...methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methylthioxanthone, 2-methyl 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-phenylsulfurylthioxanthone, 3,4-di[2-(2-methoxyethoxy)ethoxy]ethoxy carbonyl]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-propanaminium chloride. The thioxanthone compound may be a commercially available product, such as the SPEEDCURE series manufactured by Lambson (e.g., SPEEDCURE 7010, SPEEDCURE CPTX, SPEEDCURE ITX, etc.).

[0093] <Resin> The ink preferably contains at least one type of resin. In this disclosure, "resin" does not have a polymerizable group. In this disclosure, a resin having a polymerizable group corresponds to a "polymerizable compound" and is distinguished from a resin. Furthermore, a resin refers to a compound with a weight-average molecular weight of 1,000 or more.

[0094] Examples of the resin include epoxy resin, vinyl chloride resin, polyester resin, acrylic resin, urethane resin, chlorinated polyolefin, and polyketone.

[0095] The vinyl chloride resin refers to a polymer 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 a monomer other than vinyl chloride as a structural unit.

[0096] Commercially available vinyl chloride resins include, for example, UCAR Solution VinylResin VYHD, VYHH, VMCA, VROH, and VYLF-X manufactured by Dow Chemicals; Solvine Resin CL, CNL, C5R, and TA5R manufactured by Nissin Chemical Industry 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, and E15 / 40A manufactured by Wacker Chemical.

[0097] Commercially available polyester resins include, 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.

[0098] An example of the acrylic resin is a copolymer of methyl methacrylate and n-butyl methacrylate.

[0099] Commercially available acrylic resins include, for example, Elvacite 2013 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw=34,000), Elvacite 2014 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw=119,000), and Elvacite 2015 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw=119,000), all manufactured by Lucite International. 4099 (a copolymer of methyl methacrylate and n-butyl methacrylate, Mw=15,000); and DIANAL (registered trademark) BR-113 (butyl methacrylate resin, Mw=30,000) manufactured by Mitsubishi Chemical Corporation.

[0100] The urethane resin refers to a polymer having a urethane bond in the main chain, and is produced, for example, by reacting a polyisocyanate compound with a polyol compound.

[0101] An example of a commercially available chlorinated polyolefin is Superchlorine (registered trademark) 814HS manufactured by Nippon Paper Industries Co., Ltd.

[0102] Commercially available polyketone products include, for example, TEGO (registered trademark) VARIPLUS AP, CA, and SK manufactured by Evonik.

[0103] In particular, the ink preferably contains at least one resin 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 image-recording substrates, and when the ink contains these resins, the solubility of the ink in the image-recording substrate increases, improving adhesion between the image and the image-recording substrate.

[0104] -Resin T- The ink of the present disclosure preferably contains a resin T containing at least one group selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms. This increases the solubility of the ink in the image recording substrate, improving the adhesion between the image recording substrate and the image.

[0105] The resin T is preferably an acrylic resin. Resin T, an acrylic resin, is composed of structural unit A derived from polymerizable compound A containing at least one selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms, and a polarity term of the HSP value of 4.8 MPa. 1 / 2 and a structural unit B derived from the polymerizable compound B.

[0106] (Structural unit A) Resin T preferably contains a structural unit A derived from polymerizable compound A containing at least one selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms. In this case, resin T may contain only one type of structural unit A, or two or more types of structural units A.

[0107] The content of the structural unit A relative to the total amount of the resin T is preferably 40 mass % or less. The content of the structural unit A relative to the total amount of the resin T is preferably more than 0 mass %.

[0108] Because fluorohydrocarbon groups, polysiloxane groups, and hydrocarbon groups having 12 or more carbon atoms have low cohesive energy, resin T containing these groups tends to be unevenly distributed at the gas-liquid interface of the ink. As a result, when the ink is cured to form an ink film, resin T can be present at the surface of the ink film rather than the colorant (e.g., pigment) that may be contained in the ink, thereby improving the adhesion between the ink film (i.e., the image) and the lamination substrate.

[0109] From the viewpoint of distributing resin T unevenly on the surface of the ink film and improving blocking resistance, the content of structural unit A is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 5% by mass or more. On the other hand, from the viewpoint of increasing affinity with the laminate substrate and improving blocking resistance, the content of structural unit A is preferably 37% by mass or less, more preferably 32% by mass or less, and even more preferably 25% by mass or less.

[0110] A fluorohydrocarbon group means a hydrocarbon group substituted with at least one fluorine atom. Examples of the fluorinated hydrocarbon group include a fluorinated alkyl group, a fluorinated alkenyl group, and a fluorinated aryl group. As the fluorinated hydrocarbon group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred. The number of fluorine atoms in the fluorohydrocarbon group is preferably 6 or more, more preferably 8 or more. There is no particular upper limit to the number of fluorine atoms in the fluorohydrocarbon group, but the upper limit is, for example, 40. The number of carbon atoms in the fluorohydrocarbon group is preferably 3 or more, and more preferably 4 or more. There is no particular upper limit to the number of carbon atoms in the fluorohydrocarbon group, but the upper limit is, for example, 20.

[0111] Examples of hydrocarbon groups having 12 or more carbon atoms include alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, aralkyl groups, etc. As hydrocarbon groups having 12 or more carbon atoms, alkyl groups are particularly preferred. The number of carbon atoms in the hydrocarbon group having 12 or more carbon atoms is preferably 14 or more, and more preferably 16 or more. There is no particular upper limit to the number of carbon atoms in a hydrocarbon group having 12 or more carbon atoms, but the upper limit may be 30, for example.

[0112] A polysiloxane group means a divalent group containing repeating Si—O bonds. The structural unit A more preferably contains a monovalent group containing a polysiloxane group. Examples of the monovalent group containing a polysiloxane group include the following group (P).

[0113] [ka]

[0114] 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 ~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. If x is an integer greater than or equal to 2, there are multiple R P1 may be the same or different, and multiple R P2 may be the same or different. In the group (P), the number of Si—O bonds (ie, siloxane bonds) is 2 or more.

[0115] [ka]

[0116] In group (Z), R Z1 ~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. When z is an integer of 2 or more, there are multiple R Z1 may be the same or different, and there may be multiple R Z2 may be the same or different.

[0117] As x in the group (P), an integer of 1 to 50 is preferable, an integer of 1 to 20 is more preferable, and an integer of 1 to 10 is particularly preferable. In the group (P), R P1 ~R P5The hydrocarbon groups having 1 to 6 carbon atoms in each of the formulas are each independently preferably a methyl group, an ethyl group, an n-butyl group, or a phenyl group, more preferably a methyl group, an n-butyl group, or a phenyl group, and particularly preferably a methyl group or an n-butyl group.

[0118] As z in the group (Z), an integer of 0 to 50 is preferable, an integer of 0 to 20 is more preferable, and an integer of 0 to 10 is particularly preferable. In group (Z), R Z1 ~R Z5 The hydrocarbon groups having 1 to 6 carbon atoms in each of the above are each independently preferably a methyl group, an ethyl group or a phenyl group, more preferably a methyl group or a phenyl group, and particularly preferably a methyl group.

[0119] Examples of the structural unit A include structural units derived from vinyl monomers (for example, (meth)acrylic acid esters, (meth)acrylamides, etc.).

[0120] As the structural unit A, a structural unit derived from a (meth)acrylic acid ester is preferred, and a structural unit represented by the following formula (A1) is more preferred. [ka]

[0121] In the structural unit (A1), R 61 represents a hydrogen atom or a methyl group, and L 2 represents a single bond or a linking group, and X 11 represents a fluorohydrocarbon group, a monovalent group including a polysiloxane group, or a hydrocarbon group having 12 or more carbon atoms.

[0122] X 11 In the above, preferred embodiments of the fluorohydrocarbon group, the monovalent group containing a polysiloxane group, and the hydrocarbon group having 12 or more carbon atoms are as described above.

[0123] R 61 represents a hydrogen atom or a methyl group, and a methyl group is preferred.

[0124] L 2 The linking group represented by the formula (I) is preferably a divalent hydrocarbon group having 1 to 11 carbon atoms (more preferably 2 to 11 carbon atoms, and even more preferably 2 to 8 carbon atoms). The divalent hydrocarbon group may have a substituent such as a hydroxy group or an alkoxy group. Examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group, an arylene group, an alkylenearylene group, an alkylenearylenealkylene group, an alkylenecarbonyloxyalkylene group, and an arylenecarbonyloxyalkylene group. As the divalent hydrocarbon group, an alkylene group having 1 to 11 carbon atoms (more preferably 1 to 6 carbon atoms) is particularly preferred.

[0125] Specific examples of the constitutional unit represented by formula (A1) are as follows.

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] The structural unit A is a structural unit derived from a polymerizable compound A, and can be introduced into the resin T by using the polymerizable compound A as a raw material.

[0130] The polymerizable compound A may be a commercially available product. Commercially available products include, for example, X-22-174ASX, X-22-174BX, KF-2012, X-22-2426, and X-22-2404 (manufactured by Shin-Etsu Chemical Co., Ltd.); FM00711, FM-0721, FM-0725, and TM-0701T (manufactured by JNC Corporation); and Viscoat 3F and Viscoat 13F (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

[0131] In particular, from the viewpoint of further improving adhesion to the substrate for lamination, the polymerizable compound A is preferably a polymerizable compound containing at least one selected from the group consisting of a fluorohydrocarbon group and a polysiloxane group.

[0132] As the number-average molecular weight (Mn) of the polymerizable compound A increases, the effect of unevenly distributing the resin T on the surface increases, and the peelability also improves. From the viewpoint of further improving adhesion to the substrate for lamination, the number-average molecular weight of the polymerizable compound A is preferably 5,000 or less, and more preferably 3,000 or less. On the other hand, from the viewpoint of blocking resistance, the number-average molecular weight of the polymerizable compound A is preferably 400 or more, and more preferably 700 or more.

[0133] In this disclosure, number-average molecular weight is measured using gel permeation chromatography (GPC). For example, an HLC-8220GPC (manufactured by Tosoh Corporation) is used as the GPC, three TSKgel Super Multipore HZ-H columns (manufactured by Tosoh Corporation, 4.6 mm ID x 15 cm) are used as the columns, and THF (tetrahydrofuran) is used as the eluent. The conditions are a sample concentration of 0.45% by mass, a flow rate of 0.35 ml / min, a sample injection volume of 10 μl, a measurement temperature of 40°C, and detection using a refractive index (RI) detector. A calibration curve is prepared using eight standard samples of "TSK Standard Polystyrene" (manufactured by Tosoh Corporation) with product names "F-40," "F-20," "F-4," "F-1," "A-5000," "A-2500," "A-1000," and "n-propylbenzene."

[0134] When the molecular weight of the polymerizable compound A is 1,000 or less, the molecular weight is calculated from the type and number of atoms constituting the polymerizable compound A.

[0135] (Structural unit B) Resin T has a polarity term of HSP value of 4.8 MPa 1 / 2 The resin T contains a structural unit B derived from the above polymerizable compound B. The structural unit B contained in the resin T may be of only one type, or may be of two or more types.

[0136] The content of the structural unit B relative to the total amount of the resin T is 15 mass % or more. Resin T contains structural unit A in addition to structural unit B, and therefore the content of structural unit B relative to the total amount of resin T is less than 100 mass %.

[0137] Since vinyl chloride has a large polarity term in the HSP value, the polarity term in the HSP value for resin T is 4.8 MPa. 1 / 2 When the structural unit B derived from the polymerizable compound B described above is contained in an amount of 15% by mass or more, the adhesion between the image and the substrate for lamination is improved. From the above viewpoints, the content of structural unit B is preferably 25% by mass or more, more preferably 40% by mass or more, even more preferably 55% by mass or more, and particularly preferably 70% by mass or more.

[0138] The SP value (Hildebrand solubility parameter: δ) is a physical property defined as the square root of the cohesive energy density, and is a numerical value that indicates the solubility behavior of a substance. The HSP value (Hansen solubility parameter) is a parameter that takes into account the polarity of a substance by dividing the SP value into three components: the dispersion term (δD), the polar term (δP), and the hydrogen bonding term (δH). δ 2 =δD 2 +δP 2 +δH 2 It is expressed as:

[0139] In this disclosure, the dispersion term, polarity term, and hydrogen bonding term of the HSP value are calculated using the Hansen Solubility Parameter software (product name "HSPiP 5th The calculation is based on the structure of the compound using the "Diamond-like Molecular Weights Edition" (Diamond-like Molecular Weights Edition).

[0140] In order to enhance the affinity with the laminating substrate and further improve the adhesion with the laminating substrate, the polarity term of the HSP value of the polymerizable compound B is set to 5.0 MPa. 1 / 2 Preferably, it is 5.3 MPa or more. 1 / 2 More preferably, it is 5.6 MPa or more. 1 / 2 More preferably, it is equal to or greater than this.

[0141] The upper limit of the polarity term of the HSP value is not particularly limited, but is, for example, 21.5 MPa. 1 / 2 is.

[0142] In addition, in order to enhance the affinity with the laminating substrate and further improve the adhesion with the laminating substrate, the hydrogen bond term of the HSP value of the polymerizable compound B is set to 11.0 MPa. 1 / 2 Preferably, it is 10.0 MPa or less. 1 / 2 More preferably, it is 8.6 MPa or less. 1 / 2 More preferably, it is 8.0 MPa or less. 1 / 2 It is particularly preferable that the pressure is 7.5 MPa or less. 1 / 2 Most preferably, the following:

[0143] The lower limit of the hydrogen bond term of the HSP value is not particularly limited, but is, for example, 3.0 MPa 1 / 2 is.

[0144] As described above, the structural unit B contained in the resin T may be two or more types, and when the structural unit B is two or more types, the resin T is synthesized using two or more types of polymerizable compounds. When two or more polymerizable compounds are used, it is preferred that at least one polymerizable compound B among the two or more polymerizable compounds satisfies the preferred ranges for the polarity term and hydrogen bond term of the HSP value. Specifically, "in polymerizable compound B, the hydrogen bond term of the HSP value is 11.0 MPa 1 / 2The phrase "is equal to or less than 11.0 MPa" means that the hydrogen bond term of the HSP value of at least one polymerizable compound B among the two or more polymerizable compounds is 11.0 MPa or less. 1 / 2 This means that:

[0145] From the viewpoint of further improving blocking resistance, it is preferable that the structural unit B contained in the resin T be of two or more types. Specifically, polymerizable compound B has a hydrogen bond term of HSP value of 11.0 MPa. 1 / 2 Polymerizable compound B1 having a hydrogen bond term of HSP value of 11.0 MPa or less 1 / 2 and a polymerizable compound B2 which is greater than When resin T contains a structural unit B1 derived from polymerizable compound B1 and a structural unit B2 derived from polymerizable compound B2, long-term blocking resistance is improved while maintaining adhesion to the laminate substrate.

[0146] From the viewpoint of further improving adhesion to the laminate substrate and blocking resistance, the mass ratio of the content of polymerizable compound B1 to the content of polymerizable compound B2 is preferably 1 to 20, and more preferably 2 to 17.

[0147] The structural unit B is preferably at least one structural unit selected from the group consisting of the following formulae (1) to (5).

[0148] [ka]

[0149] In formula (1), R 11 represents a hydrogen atom or a hydrocarbon group, and R 12 and R 13 R each independently represents a hydrocarbon group which may contain an oxygen atom or a hydrogen atom. 12 and R 13 may be bonded to each other to form a ring. In formula (2), R 21 represents a hydrogen atom or a hydrocarbon group, and R 22 and R23 R each independently represents a hydrocarbon group which may contain an oxygen atom or a hydrogen atom. 22 and R 23 may be bonded to each other to form a ring. In formula (3), R 31 represents a hydrogen atom or a hydrocarbon group, and L 11 represents a single bond or a divalent linking group, R 32 represents a hydrocarbon group containing at least one selected from the group consisting of -O-, -S-, -C(=O)-, -NH-, and -N<. In formula (4), R 41 represents a hydrogen atom or a hydrocarbon group, and R 42 and R 43 R each independently represents a hydrogen atom, a cyano group, a hydrocarbon group having a carbonyl group, a phosphate ester group, or a heterocyclic group. 42 and R 43 may be bonded to each other to form a ring. In formula (5), R 51 represents a hydrogen atom or a hydrocarbon group.

[0150] -Formula (1)- In formula (1), R 11 is preferably a hydrogen atom or a methyl group. In formula (1), R 12 and R 13 The hydrocarbon group represented by the formula (I) may be a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group, but is preferably a linear hydrocarbon group.

[0151] R 12 and R 13 The hydrocarbon group represented by the formula (I) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group. That is, R 12 and R 13 The hydrocarbon group represented by the formula (I) is more preferably a linear alkyl group.

[0152] R 12 and R13 The hydrocarbon group represented by the following formula preferably has 1 to 10 carbon atoms.

[0153] Examples of hydrocarbon groups that may contain an oxygen atom include an -O-monovalent hydrocarbon group, a -divalent hydrocarbon group -OH, a -divalent hydrocarbon group -O-monovalent hydrocarbon group, and a -divalent hydrocarbon group -C=(O)O-monovalent hydrocarbon group.

[0154] R 12 and R 13 are preferably each independently a hydrocarbon group which may contain an oxygen atom, from the viewpoints of reducing the hydrogen bonding property of resin T, increasing the affinity with the polymer containing vinyl chloride as a structural unit, and reducing the viscosity of the ink.

[0155] Also, R 12 and R 13 Preferably, R are bonded to each other to form a ring. 12 and R 13 The ring formed by bonding together is preferably a 5- to 8-membered ring.

[0156] Examples of the constitutional unit represented by formula (1) include the following constitutional units.

[0157] [ka]

[0158] -Formula (2)- In equation (2), R 21 is preferably a hydrogen atom or a methyl group. In equation (2), R 22 and R 23 The hydrocarbon group represented by the formula (I) may be a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group, but is preferably a linear hydrocarbon group.

[0159] R 22 and R 23The hydrocarbon group represented by the formula (I) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group. That is, R 22 and R 23 The hydrocarbon group represented by the formula (I) is more preferably a linear alkyl group.

[0160] R 22 and R 23 The hydrocarbon group represented by the formula (I) preferably has 1 to 10 carbon atoms, and more preferably 2 to 8 carbon atoms.

[0161] Examples of hydrocarbon groups that may contain an oxygen atom include the -divalent hydrocarbon group -OH, the -divalent hydrocarbon group -O-monovalent hydrocarbon group, the -divalent hydrocarbon group -C=(O)-monovalent hydrocarbon group, and the -divalent hydrocarbon group -C=(O)O-monovalent hydrocarbon group.

[0162] In equation (2), R 22 and R 23 are preferably each independently a hydrocarbon group which may contain an oxygen atom, from the viewpoints of reducing the hydrogen bonding property of resin T, increasing the affinity with the polymer containing vinyl chloride as a structural unit, and reducing the viscosity of the ink.

[0163] Also, R 22 and R 23 Preferably, R are bonded to each other to form a ring. 22 and R 23 The ring formed by bonding together is preferably a 5- to 8-membered ring.

[0164] Examples of the constitutional unit represented by formula (2) include the following constitutional units.

[0165] [ka]

[0166] -Formula (3)- In equation (3), R 31is preferably a hydrogen atom or a methyl group. In equation (3), L 11 The divalent linking group represented by the formula (L11) is preferably an alkylene group having 1 to 3 carbon atoms or a group represented by any one of the following formulae (L11) to (L14), more preferably an alkylene group having 1 to 3 carbon atoms or a group represented by any one of the following formulae (L11) to (13), and even more preferably an alkylene group having 1 to 3 carbon atoms or a group represented by the following formula (L11).

[0167] [ka]

[0168] In formula (L11), L represents an alkylene group having 1 to 3 carbon atoms, n represents an integer of 1 to 4, *1 represents the bonding position to the oxygen atom, *2 represents R 32 represents the bonding position with In formula (L12), L represents an alkylene group having 1 to 3 carbon atoms, *1 represents the bonding position with the oxygen atom, *2 represents R 32 represents the bonding position with In formula (L13), L 1 and L 2 each independently represents an alkylene group having 1 to 3 carbon atoms, *1 represents the bonding position with the oxygen atom, *2 represents R 32 represents the bonding position with In formula (L14), *1 represents the bonding position with the oxygen atom, and *2 represents the bonding position with the oxygen atom. 32 represents the bonding position with

[0169] In formula (L11), n ​​is preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 1.

[0170] In equation (3), R 32 The hydrocarbon group represented by the formula (I) may be a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group, but is preferably a hydrocarbon group containing a ring structure.

[0171] R32 The hydrocarbon group represented by the formula (I) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group.

[0172] R 32 The hydrocarbon group represented by the formula (I) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, further preferably 3 to 12 carbon atoms, and particularly preferably 3 to 10 carbon atoms.

[0173] In the hydrocarbon group containing at least one selected from the group consisting of -O-, -S-, -C(=O)-, -NH-, and -N<, examples of combinations of two or more of -O-, -S-, -C(=O)-, -NH-, and -N< include -C(=O)O-, -OC(=O)O-, -C(=O)-NH-, and a pyrrolidone ring.

[0174] R 32 is preferably a hydrocarbon group containing -C(=O)-NH-, a hydrocarbon group containing -C(=O)O-, a hydrocarbon group containing -OCO-, or a hydrocarbon group containing a hydroxyl group.

[0175] Examples of the constitutional unit represented by formula (3) include the following constitutional units.

[0176] [ka]

[0177] -Formula (4)- In equation (4), R 41 is preferably a hydrogen atom or a methyl group. In equation (4), R 42 and R 43 The monovalent heterocyclic group represented by the following formula (I) refers to a group in which one hydrogen atom has been removed from a heterocyclic compound. The heterocycle in the monovalent heterocyclic group is preferably a 5- or 6-membered ring. The heterocycle may form a condensed ring with an aliphatic ring, an aromatic ring, or another heterocycle.

[0178] Examples of the heteroatom in the hetero ring include an N atom, an O atom, and an S atom, with an N atom being preferred.

[0179] Examples of the heterocycle include a pyridine ring, a piperidine ring, a furan ring, a furfuran ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, an indole ring, an imidazole ring, a pyrazole ring, a carbazole ring, a phenothiazine ring, a phenoxazine ring, an indoline ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiadiazine ring, a benzoquinoline ring, and a thiadiazole ring.

[0180] In equation (4), R 42 and R 43 are preferably each independently a cyano group or a monovalent heterocyclic group, from the viewpoint of increasing affinity with the polymer containing vinyl chloride as a structural unit.

[0181] Examples of the constitutional unit represented by formula (4) include the following constitutional units.

[0182] [ka]

[0183] -Formula (5)- In equation (5), R 51 The hydrocarbon group represented by the formula (I) may be a straight-chain hydrocarbon group, a branched-chain hydrocarbon group, or a cyclic hydrocarbon group.

[0184] R 51 The hydrocarbon group represented by the formula (I) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group.

[0185] R 51 The hydrocarbon group represented by the following formula preferably has 1 to 10 carbon atoms.

[0186] Examples of the constitutional unit represented by formula (5) include the following constitutional units.

[0187] [ka]

[0188] The structural unit B is a structural unit derived from a polymerizable compound B, and can be introduced into the resin T by using the polymerizable compound B as a raw material.

[0189] The polarity term (δP) and hydrogen bond term (δH) of the HSP value for each polymerizable compound are shown below. The unit is MPa. 1 / 2 is. Of the following polymerizable compounds, the polarity term of the HSP value is 4.8 MPa. 1 / 2 A polymerizable compound having a molecular weight of less than 1000 does not fall under the category of polymerizable compound B. Of the following polymerizable compounds, the polarity term of the HSP value is 4.8 MPa. 1 / 2 The above polymerizable compounds correspond to polymerizable compound B. In the case of polymerizable compounds derived from structural units represented by the above formulas (1) to (5), the corresponding formulas are shown.

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] Resin T preferably contains two or more types of structural unit B. When the resin T contains two or more types of structural units B, the structural units B preferably contain a structural unit represented by formula (1) and a structural unit represented by formula (2), or a structural unit represented by formula (1) and a structural unit represented by formula (3).

[0197] From the viewpoint of distributing resin T unevenly on the surface of the ink film and improving blocking resistance, the mass ratio of structural unit A to structural unit B is preferably 0.01 or more, more preferably 0.03 or more, and even more preferably 0.05 or more. From the viewpoint of increasing affinity with the laminating substrate and improving blocking resistance, the mass ratio of structural unit A to structural unit B is preferably 0.65 or less, more preferably 0.55 or less, even more preferably 0.45 or less, and particularly preferably 0.35 or less. From the above viewpoints, the mass ratio of structural unit A to structural unit B is preferably from 0.01 to 0.65, more preferably from 0.03 to 0.55, even more preferably from 0.05 to 0.45, and particularly preferably from 0.05 to 0.35.

[0198] From the viewpoint of further improving the blocking resistance of the image, it is particularly preferable that the resin T contains a structural unit derived from hydroxyethyl methacrylate, where hydroxyethyl methacrylate corresponds to the structural unit represented by formula (3) among the structural units B described above. The mass ratio of the structural unit A to the structural unit B is as described above. The content of structural units derived from hydroxyethyl (meth)acrylate relative to the total amount of Resin T is preferably 2% by mass to 40% by mass, more preferably 3% by mass to 30% by mass, and even more preferably 5% by mass to 20% by mass.

[0199] Resin T may contain other structural units in addition to structural units A and B.

[0200] From the viewpoint of improving adhesion to the laminating substrate, the total content of the structural units A and B is preferably 30% by mass or more, more preferably 45% by mass or more, and even more preferably 60% by mass or more, relative to the total amount of the resin T. The total content of the structural units A and B may be 100% by mass. In other words, the resin T may be composed only of the structural units A and B.

[0201] When the resin T contains other structural units, the other structural units are not particularly limited, and examples thereof include structural units derived from monofunctional polymerizable monomers described below.

[0202] (Physical Properties) The glass transition temperature of resin T is preferably 150° C. or lower, more preferably 130° C. or lower, and even more preferably 100° C. or lower. There are no particular restrictions on the lower limit of the glass transition temperature, but from the viewpoint of blocking resistance, it is preferably −20° C.

[0203] In the present disclosure, the glass transition temperature is measured using a differential scanning calorimeter, for example, a product named "DSC-60" manufactured by Shimadzu Corporation.

[0204] If the glass transition temperature of the resin T is 150° C. or less, the mobility of the resin T improves when the laminate substrate is thermocompression bonded to the image, and the adhesion to the laminate substrate improves.

[0205] The solubility parameter (SP value) of resin T is 7.5 MPa. 1 / 2 ~14.0MPa 1 / 2Preferably, the pressure is 8.5 MPa. 1 / 2 ~13.0MPa 1 / 2 More preferably, it is 9.5 MPa. 1 / 2 ~12.0MPa 1 / 2 It is more preferable that:

[0206] In the present disclosure, the SP value means the Hansen solubility parameter.

[0207] The SP value of Resin T is calculated by the following method. Completely dissolve 100 mg of sample in 2 mL of THF, add deionized water or n-hexane dropwise to the solution, and calculate the SP value of the sample using the following formula from the volume fraction at which the solution becomes cloudy. SP value of THF = δ T SP value of water = δ W SP value of n-hexane = δ H Volume fraction (water): DI water / (DI water + THF) = V W Volume fraction (hexane): hexane / (hexane + THF) = V H SP value of deionized water / THF mixed solution = δ WT =δ T ×(1-V W )+δ W ×V W SP value of n-hexane / THF mixed solution = δ HT =δT×(1-V H )+δ H ×V H SP value of sample = δ P =(δ WT ×(V W ) 0.5 +δ HT ×(VH) 0.5 ) / ((VW) 0.5 +(VH) 0.5 )

[0208] When the SP value of the resin T is within the above range, the adhesion to the substrate for lamination is improved.

[0209] From the viewpoint of improving adhesion to the substrate for lamination, the weight-average molecular weight of Resin T is preferably at least 1000, more preferably at least 3000, and even more preferably at least 5000. On the other hand, from the viewpoint of ink ejection properties and storage stability, the weight-average molecular weight of Resin T is preferably at most 80000, more preferably at most 60000, and even more preferably at most 40000.

[0210] In the present disclosure, the weight average molecular weight is measured by a method similar to the method for measuring the number average molecular weight described above.

[0211] From the viewpoint of improving adhesion to the laminating substrate, the content of Resin T is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, relative to the total amount of ink. On the other hand, from the viewpoint of ink ejection properties and storage stability, the content of Resin T is preferably 10.0% by mass or less, more preferably 8.0% by mass or less, even more preferably 6.0% by mass or less, and even more preferably 3.0% by mass or less, relative to the total amount of ink.

[0212] The weight average molecular weight (Mw) of the resin is preferably 1000 to 70,000, and more preferably 5000 to 50,000.

[0213] When the ink of the present disclosure contains a resin, the content of the resin is preferably 0.1% by mass to 10.0% by mass, more preferably 0.3% by mass to 8.0% by mass, even more preferably 0.5% by mass to 6.0% by mass, and even more preferably 0.5% by mass to 3.0% by mass, relative to the total amount of the ink.

[0214] <Water> The inks of the present disclosure may contain small amounts of water. Specifically, the content of water relative to the total amount of ink is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The ink is preferably a non-aqueous ink that is substantially free of water.

[0215] <Coloring agent> The inks of the present disclosure preferably include at least one colorant. The colorant is not particularly limited, and can be arbitrarily selected from known colorants such as pigments, water-soluble dyes, disperse dyes, etc. Among these, pigments are preferred as the colorant in terms of excellent weather resistance and color reproducibility.

[0216] 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 "Encyclopedia of Pigments" edited by Seijiro Ito (published in 2000), "Industrial Organic Pigments" by W. Herbst and K. Hunger, and JP-A Nos. 2002-12607, 2002-188025, 2003-26978, and 2003-342503.

[0217] When the ink of the present disclosure uses a pigment as the colorant, it may contain a dispersant as needed.

[0218] For colorants such as pigments and pigment dispersants, known documents such as paragraphs 0152 to 0158 of JP-A No. 2011-225848 and paragraphs 0132 to 0149 of JP-A No. 2009-209352 can be appropriately referenced.

[0219] When the ink of the present disclosure contains a colorant, the content of the colorant is preferably 0.1% to 20% by mass, and more preferably 0.5% to 10% by mass, relative to the total amount of the ink.

[0220] <Other ingredients> The ink of the present disclosure may contain other components in addition to those described above. Other components include ultraviolet absorbers, co-sensitizers, antioxidants, anti-fading agents, conductive salts, and the like. For other components, reference can be made to known documents such as JP-A-2011-225848 and JP-A-2009-209352, as appropriate.

[0221] <Ink properties> From the viewpoint of ejection properties, the viscosity of the ink of the present disclosure is preferably 4 mPa·s to 50 mPa·s, more preferably 10 mPa·s to 30 mPa·s, and even more preferably 10 mPa·s to 25 mPa·s.

[0222] Viscosity refers to the value measured at 25°C. The viscosity is a value measured using a viscometer, and can be measured using, for example, a VISCOMETER RE-85L (manufactured by Toki Sangyo Co., Ltd.).

[0223] From the viewpoint of ejection properties, the surface tension of the ink of the present disclosure 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.

[0224] The surface tension refers to the value measured at 25°C. The surface tension is a value measured using a surface tensiometer, and can be measured using, for example, an Automatic Surface Tentiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[0225] [Image Recording Method] The image recording method of the present disclosure includes a step of applying the ink of the present disclosure described above to an image recording substrate containing a polymer including vinyl chloride as a constituent unit by an inkjet recording method to record an image (hereinafter also referred to as an image recording step). The image recording method of the present disclosure uses the ink of the present disclosure, and therefore exhibits the same effects as those of the ink of the present disclosure described above (that is, the effect of improving lamination strength and blocking resistance).

[0226] <Image recording process> The image recording step is a step of applying the ink of the present disclosure described above to an image recording substrate containing a polymer containing vinyl chloride as a structural unit by an inkjet recording method to record an image.

[0227] (Image recording substrate) The image recording substrate used in the image recording step contains a polymer containing vinyl chloride as a constituent unit.

[0228] A 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 a monomer other than vinyl chloride as a structural unit.

[0229] Examples of copolymers containing vinyl chloride and a monomer 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.

[0230] In particular, the image recording substrate preferably contains polyvinyl chloride.

[0231] The image recording substrate may contain components other than the polymer containing vinyl chloride as a structural unit, such as a plasticizer, a stabilizer, an antioxidant, an ultraviolet absorber, a binder resin, and a white pigment.

[0232] 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 adhesion between the image recording substrate and the image by dissolving the ink in the image recording substrate, it is preferable that the image recording substrate does not have a surface treatment layer. In other words, the surface of the image recording substrate to which the ink is applied preferably contains a polymer containing vinyl chloride as a structural unit.

[0233] The thickness of the image recording substrate is not particularly limited, but is preferably 0.1 μm to 1,000 μm, more preferably 0.1 μm to 800 μm, and even more preferably 1 μm to 500 μm.

[0234] (Ink application) In the image recording process, the ink is applied by an ink jet recording method. There are no particular limitations on the ink ejection method used in inkjet recording, and any of the well-known methods may be used, such as a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink with it, thereby ejecting the ink using radiation pressure, and a thermal inkjet (Bubble Jet (registered trademark)) method that heats the ink to form bubbles and uses the resulting pressure.

[0235] As an inkjet recording method, in particular, the method described in JP-A-54-59936 can be effectively used, in which ink subjected to the action of thermal energy undergoes a sudden change in volume, and the ink is ejected from the nozzles by the force caused by this state change. As an inkjet recording method, the method described in paragraphs 0093 to 0105 of JP-A-2003-306623 can also be used.

[0236] The application of ink onto an image recording substrate by ink jet recording is carried out by ejecting the ink from the nozzles of an ink jet head.

[0237] Inkjet head methods include the shuttle method, in which a short serial head is scanned across the width of the recording medium to perform printing, and the line method, which uses a line head in which printing elements are arranged to cover the entire area of ​​one side of the recording medium.

[0238] The line method allows for image recording over the entire surface of a recording medium by scanning the recording medium 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 a short head, as in the shuttle method. Furthermore, compared to the shuttle method, the line method does not require complex scanning control of the carriage movement and the recording medium, and only the recording medium moves. Therefore, the line method achieves faster image recording speeds than the shuttle method.

[0239] The ink is preferably applied using an inkjet head having a resolution of 300 dpi or more (more preferably 600 dpi or more, and even more preferably 800 dpi or more), where dpi stands for dots per inch, and 1 inch is 2.54 cm.

[0240] 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, from the viewpoint of obtaining high-definition images.

[0241] (Heating process) The image recording step may include a step of heating the applied ink after the ink has been applied onto the image recording substrate (hereinafter also referred to as a "heating step").

[0242] The heating temperature is preferably 30°C to 90°C, more preferably 30°C to 50°C.

[0243] Examples of heating methods include methods using infrared rays (IR), hot air, and heating devices (for example, heaters, hot plates, heating furnaces, etc.).

[0244] Heating can be carried out by heating the ink from at least one of the image recording surface side and the non-image recording surface side of the image recording substrate.

[0245] <Active energy ray irradiation process> The image recording step preferably includes a step of applying an ink onto an image recording substrate and then irradiating the applied ink with active energy rays (hereinafter also referred to as an "active energy ray irradiation step").

[0246] 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, etc., of the image.

[0247] Examples of active energy rays include ultraviolet rays, visible light rays, and electron beams, with ultraviolet rays being preferred.

[0248] The peak wavelength of the ultraviolet light is preferably 200 nm to 405 nm, and more preferably 220 nm to 390 nm.

[0249] The UV exposure dose was 20 mJ / cm 2 ~5J / cm 2 and preferably 100 mJ / cm 2 ~1,500mJ / cm 2 The irradiation conditions and basic irradiation method can be those disclosed in JP-A-60-132767. Specifically, the irradiation method is preferably a method in which light sources are provided on both sides of a head unit including an ink ejection device and the head unit and light sources are scanned using a so-called shuttle method, or a method in which irradiation is performed using a separate light source that does not involve driving.

[0250] Discharge lamps and laser light sources (gas lasers, solid-state lasers, etc.) are mainly used as light sources for ultraviolet irradiation, and widely known 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, long-lasting, highly efficient, and low-cost, and are expected to be used as light sources for ultraviolet irradiation. Among these, metal halide lamps, high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, and UV-LEDs are preferred light sources for ultraviolet irradiation.

[0251] [Method for manufacturing laminated body] The method for producing a laminate according to the present disclosure includes: A step of obtaining an image recording material including an image recording substrate and an image by the image recording method of the present disclosure described above; a step of laminating an image recorded material and a laminate substrate containing a polymer containing vinyl chloride as a structural unit, with the image on the image recorded material and the laminate substrate facing each other to obtain a laminate (hereinafter also referred to as a laminating step); Includes. The method for producing a laminate according to the present disclosure includes the image recording method according to the present disclosure, and therefore exhibits the same effects as those achieved by the ink according to the present disclosure described above (i.e., the effect of improving laminate strength and blocking resistance).

[0252] <Step of Obtaining an Image Recorded Material> For the process of obtaining an image recording, the image recording method of the present disclosure described above can be referred to.

[0253] <Lamination process> The lamination process is a process in which the above-mentioned image recording material (i.e., an image recording material containing an image recording substrate and an image) is laminated with a laminate substrate containing a polymer containing vinyl chloride as a constituent unit in such a manner that the image in the image recording material faces the laminate substrate to obtain a laminated body.

[0254] (Laminating substrate) The preferred embodiments of the substrate for lamination are the same as the preferred embodiments of the substrate for image recording described above, and therefore, the description thereof will be omitted.

[0255] (Lamination method) In the laminating step, the image and the laminate substrate are laminated in an opposing arrangement. In this case, the image may be laminated so that it comes into contact with the laminate substrate, or may be laminated via another layer. However, from the viewpoint of more effectively improving the laminate strength, it is preferable to laminate the image and the laminate substrate so that they come into contact with each other in the lamination process, thereby obtaining a laminated body having a laminated structure of substrate for lamination / image / image-recording substrate.

[0256] In the lamination step, the image and the substrate for lamination are preferably thermocompression bonded at a temperature of 100° C. or higher. Because the weighted average Tg of the homopolymer of the polymerizable monomer contained in the ink is 0° C. to 50° C., thermocompression bonding at a temperature of 50° C. or higher effectively heat-seals the image and the substrate for lamination, further improving the adhesion between the image and the substrate for lamination. The temperature for thermocompression bonding is more preferably 100°C or higher.

[0257] The upper limit of the temperature during thermocompression bonding is preferably 200°C, more preferably 160°C, and even more preferably 140°C, from the viewpoint of suppressing thermal decomposition.

[0258] The temperature during thermocompression bonding refers to the surface temperature of the substrate for lamination.

[0259] The pressure applied during thermocompression bonding is preferably 0.1 MPa to 20 MPa, and more preferably 0.5 MPa to 15 MPa.

[0260] The time for thermocompression bonding is, for example, 10 seconds to 500 seconds.

[0261] Thermocompression bonding may be performed in two stages. For example, the pressure in the first stage may be 0.5 MPa to 5 MPa, and the pressure in the second stage may be higher than the pressure in the first stage, at 6 MPa to 15 MPa.

[0262] The laminate obtained by the method for producing a laminate according to the present disclosure can be used, for example, as a flooring or wall material for transportation equipment (trains, buses, etc.) or as a flooring or wall material for buildings. [Example]

[0263] Hereinafter, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to the following examples as long as it does not depart from the gist of the disclosure. Hereinafter, the photopolymerization initiator may be simply referred to as "initiator."

[0264] [Examples 1 to 24, Comparative Examples 1 to 3] <Preparation of cyan pigment dispersion> The following components were mixed and stirred for 10 minutes at 2,500 rpm using a mixer (Silverson L4R) to obtain a mixture. The mixture was then placed in a bead mill disperser DISPERMAT LS (VMA) and dispersed for 6 hours at 2,500 rpm using 0.65 mm diameter YTZ balls (Nikkato Corporation) to obtain a cyan pigment dispersion.

[0265] Cyan pigment (PB15:3 (Pigment Blue 15:3); product name "IRGALITE BLUE GLVO", manufactured by BASF)... 30% by mass Dispersant (BYK-168; product name "DISPERSE BYK-168", manufactured by BYK)... 20% by mass DVE-3 (triethylene glycol divinyl ether (bifunctional monomer), manufactured by BASF)...50% by mass

[0266] <Ink Preparation> The cyan pigment dispersion liquid was mixed with the components shown in Tables 1 to 4 other than the components contained in the cyan pigment dispersion liquid so as to obtain the contents shown in Tables 1 to 4, thereby preparing inks.

[0267] Details of each component other than the cyan pigment, dispersant, and DVE-3 in Tables 1 to 4 are as follows.

[0268] (polymerizable monomer) -Monomer A- THFA: Tetrahydrofurfuryl acrylate EOEOEA: Ethoxydiethylene glycol acrylate CHA: Cyclohexyl acrylate IBOA: Isobornyl acrylate 4-HBA: 4-hydroxybutyl acrylate PEA: Phenoxyethyl acrylate

[0269] - N-vinyl compounds - NVC: N-vinylcaprolactam

[0270] -Other compounds- ·LA: Lauryl acrylate IOA: Isooctyl acrylate ACMO: 4-Acryloylmorpholine DVE-3 (bifunctional): Triethylene glycol divinyl ether (bifunctional monomer, manufactured by BASF)

[0271] (Sensitizing dye) DETX: 2,4-diethylthioxanthen-9-one

[0272] (Photopolymerization initiator) -α-aminoketone photopolymerization initiator with a molecular weight of 600 or more- Omni.910: Polyethylene glycol di(β-4-[4-(2-dimethylamino-2-benzyl)butonylphenyl]piperazine)propionate (product name "Omnipol 910", manufactured by IGM Resins BV, chemical structure shown below)

[0273] [ka]

[0274] Initiator 4: 2,8-Diallyl-2,8-bis-dimethylamino-1,9-bis-[4-(2-hydroxyethylamino)-phenyl]-nonane-1,9-dione (The structure is as follows: The synthesis was carried out according to the method described in paragraphs 0260 to 0271 of JP-A-2007-525573.

[0275] [ka]

[0276] Initiator 5: 1-Piperazinepropionic acid, 4,4'-[1,4-piperazinediylbis[carbonyl-4,1-phenylene[2-(dodecylmethylamino)-2-ethyl-1-oxo-3,1-propanediyl]-4,1-phenylene]bis-,1,1'-bis(13-oxo-3,6,9,12-tetraoxapentadec-14-en-1-yl) ester (The structure is as follows:)

[0277] [ka]

[0278] Initiator 5 was synthesized according to the method described in paragraphs 0128 to 0186 of WO 2017 / 195428. In step I, the halogenated benzene used was fluorinated benzene, and the acid halide compound having a halide atom at the α-position was 2-bromobutyric acid chloride. The secondary monoamine compound used in Step II was methyldodecylamine. In Step III, benzyl bromide having a substituent (-Y3-C(=O)-OR) as a substituent on the aromatic nucleus (wherein R is an alkyl group or a hydrogen atom) was prepared using methyl bromomethylbenzoate. In step IV, general formula 4 was used as piperazine. In step V, general formula 5 used piperazine. Step VI was synthesized in Step VI-8 so that the structure of Y1 would be the same as that of Exemplified Compound M1.

[0279] -Acylphosphine oxide photopolymerization initiator- Omni.819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (product name "Omnirad 819", manufactured by IGM Resins BV)

[0280] -Other initiators- Omni.369: 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (product name "Omnirad 369", manufactured by IGM Resins BV) [α-aminoketone photoinitiator with a molecular weight of less than 600]

[0281] (polymerization inhibitor) TEMPOL: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl

[0282] (Resin T (with HEMA)) Resin T-1: A copolymer of NVC / HEMA / single-terminated methacrylic silicone = 85 / 5 / 10 (mass ratio). The synthesis method is as follows. Resin T-2: A copolymer of NVC / HEMA / single-terminated methacrylic silicone = 70 / 20 / 10 (mass ratio). The synthesis method is as follows.

[0283] - Synthesis of Resin T-1 (NVC / HEMA / single-end methacrylic-modified silicone = 85 / 5 / 10 (mass ratio) copolymer) - 1-Propanol (203.7 g) and N-vinylcaprolactam (NVC) (127.5 g) were weighed into a 1 L three-neck flask equipped with a condenser and heated and stirred 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 (single-terminated methacrylic silicone) (Shin-Etsu Chemical Co., Ltd.) (15.0 g), and V-601 (2,2'-azobis(isobutyrate)dimethyl; polymerization initiator, Fujifilm Wako Pure Chemical Industries, Ltd.) (10.5 g) was added dropwise to the flask over 3 hours. After the dropwise addition was completed, the mixture was stirred at 75 °C for an additional hour, then heated to 90 °C and reacted for an additional 3 hours. After cooling to room temperature (25°C; the same applies below), phenoxyethyl acrylate (PEA) (350.0 g) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyl-1-oxyl (TEMPOL) (3.5 g) were added, and the 1-propanol was distilled off under reduced pressure at 80°C / 50 hPa to obtain a 30% by weight solution of Resin T-1 (a copolymer of NVC / HEMA / single-terminated methacrylic acid-modified silicone = 85 / 5 / 10 (mass ratio)). The weight-average molecular weight of Resin T-1 was 5000.

[0284] - Synthesis of Resin T-2 (NVC / HEMA / single-end methacrylic-modified silicone = 70 / 20 / 10 (mass ratio) copolymer) - 1-Propanol (81.6 g) was weighed into a 1 L three-neck flask equipped with a condenser and heated to 90 °C with stirring under a nitrogen stream. Separately, Dropping Solution 1 was prepared by mixing 1-propanol (27.2 g), hydroxyethyl methacrylate (HEMA) (12.0 g), X-22-174ASX (single-terminated methacrylate-modified silicone) (Shin-Etsu Chemical Co., Ltd.) (6.0 g), and V-601 (2,2'-azobis(isobutyrate)dimethyl; polymerization initiator, Fujifilm Wako Pure Chemical Industries, Ltd.) (3.0 g). Dropping Solution 2 was prepared by mixing 1-propanol (27.2 g) and N-vinylcaprolactam (NVC) (42.0 g). Dropping Solution 1 was added dropwise to the flask at a constant rate so that the dropwise addition was completed within 2 hours, and Dropping Solution 2 was added dropwise to the flask at a constant rate so that the dropwise addition was completed within 1 hour. After the addition of Droplet 1 was completed, the mixture was stirred for an additional hour, after which V-601 (1.7 g) was added and the reaction was continued for an additional 3 hours. The mixture was allowed to cool to room temperature (25°C; the same applies below), and then phenoxyethyl acrylate (PEA) (140.0 g) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyl-1-oxyl (TEMPOL) (1.4 g) were added. The 1-propanol was distilled off under reduced pressure at 80°C / 50 hPa to obtain a 30% by weight solution of Resin T-2 (a copolymer of NVC / HEMA / single-end methacrylic-modified silicone = 70 / 20 / 10 (mass ratio)). The weight-average molecular weight of Resin T-2 was 10,000.

[0285] (Resin T (without HEMA)) Resin T-3: A copolymer of NVC / THFA / single-terminated methacrylic silicone = 60 / 30 / 10 (mass ratio). The synthesis method is as follows.

[0286] - Synthesis of Resin T-3 (NVC / THFA / single-end methacrylic-modified silicone = 60 / 30 / 10 (mass ratio) copolymer) - 1-Propanol (205.5 g) and N-vinylcaprolactam (NVC) (90.0 g) were weighed into a 1 L three-neck flask equipped with a condenser and heated and stirred at 75 °C under a nitrogen stream. Separately, a mixed solution prepared by mixing 1-propanol (137.0 g), tetrahydrofurfuryl acrylate (THFA) (45.0 g), X-22-174ASX (single-terminated methacrylic-modified silicone) (Shin-Etsu Chemical Co., Ltd.) (15.0 g), and V-601 (2,2'-azobis(isobutyrate)dimethyl; polymerization initiator, Fujifilm Wako Pure Chemical Industries, Ltd.) (7.5 g) was added dropwise to the flask over 3 hours. After the dropwise addition was completed, the mixture was stirred at 75 °C for an additional hour, then heated to 90 °C and reacted for an additional 3 hours. After cooling to room temperature (25°C; the same applies below), phenoxyethyl acrylate (350.0 g) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyl-1-oxyl (TEMPOL) (3.5 g) were added, and the 1-propanol was distilled off under reduced pressure at 80°C / 50 hPa to obtain a 30% by weight solution of Resin T-3 (a copolymer of NVC / THFA / single-end methacrylic-modified silicone = 60 / 30 / 10 (mass ratio)). The weight-average molecular weight of Polymer Additive 3 was 17,000.

[0287] <Preparation of image recording material> A polyvinyl chloride substrate (product name "PVC35phr", manufactured by Okamoto Corporation) was prepared as an image recording substrate. An ultraviolet (UV) irradiation device (Vzero, manufactured by Integration Technology) was attached to an Affit inkjet printer (KEGON), preparing a modified inkjet printer. The time until UV irradiation (i.e., the time from when the ink ejected from the inkjet head lands on the image recording substrate until UV irradiation) was adjusted to 10 seconds. The time until UV irradiation was adjusted by adjusting the conveying speed (5 m / min to 25 m / min) and the timing of opening and closing the UV shutter. The ink was ejected from the inkjet head of a modified inkjet printer and applied to an image recording substrate. The resolution was 1200 dpi (dots per inch) x 600 dpi. The applied ink was then irradiated with UV light (exposure amount: 1200 mJ / cm) by the UV irradiation device. 2 ) and images were obtained. In this way, an image recording material containing an image recording substrate and an image was obtained.

[0288] <Creating a laminate> A polyvinyl chloride substrate (product name "SG800", manufactured by KN Trading Co., Ltd., thickness 75 μm) was used as the substrate for lamination. A laminating substrate was placed on the image of the image-recorded product obtained above (i.e., on the image recorded on the image-recording substrate). In this state, the image-recorded product and the laminating substrate were thermocompression-bonded using a tabletop automatic transfer press (product name "AF-54TEN", Asahi Textile Machinery Co., Ltd.). This resulted in a laminate having a layered structure of image-recording substrate / image / laminating substrate. The temperature for thermocompression bonding was 130° C. The thermocompression bonding was performed at a pressure of 2 MPa for 300 seconds, and then at a pressure of 10 MPa for 60 seconds.

[0289] <Evaluation of laminate strength> The evaluation samples were prepared in the following manner. A 3.2 cm x 3.2 cm image recording sample was cut out from the image recording material obtained above, and a 3.2 cm x 3.2 cm laminating substrate sample was cut out from the laminating substrate. A 12 μm thick PET (polyethylene terephthalate) sheet was 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 laminating substrate sample was placed on the image recording surface of the image recording sample, covering the entire area where the PET sheet was placed (1.0 cm × 3.2 cm area) and the entire area where the PET sheet was not placed (2.2 cm × 3.2 cm area). In this state, the image recording sample and the laminating substrate sample were laminated under the same conditions as in the laminating step described above.The PET sheet was removed from the resulting laminate to obtain a sample for evaluation. In the evaluation sample, the image recording sample and the laminating substrate sample were bonded in the area where the PET sheet was not placed before the laminating process, whereas in the evaluation sample, the image recording sample and the laminating substrate sample were not bonded in the area where the PET sheet was placed before the laminating process. Next, in the area where the image recording sample and the laminating substrate sample were not bonded, a tensile test was conducted in which the image recording sample and the laminating substrate sample were pulled in opposite directions to measure the peel strength (i.e., lamination strength). The tensile test was conducted using a tensile tester (product name "Autograph AGS-X 5KN", manufactured by Shimadzu Corporation). Two evaluation samples were prepared, and the tensile test was conducted twice. The average value of the two lamination strengths was used. The evaluation criteria are as follows: In the following evaluation criteria, the most excellent rank for lamination strength is "5".

[0290] -Laminate strength evaluation criteria- 5: The laminate strength was 7 N / cm or more. 4: The laminate strength was 3 N / cm or more and less than 7 N / cm. 3: The laminate strength was 2 N / cm or more and less than 3 N / cm. 2: The laminate strength was 1 N / cm or more and less than 2 N / cm. 1: The laminate strength was 0.1 N / cm or more and less than 1 N / cm. 0: The laminate strength was less than 0.1 N / cm.

[0291] <Evaluation of blocking resistance> From the image recording obtained above, an image recording sample measuring 2.2 cm x 2.2 cm was cut out. Both sides of the obtained image recording sample were sandwiched between 2.2 cm × 2.2 cm polyvinyl chloride substrates, both sides of the obtained laminate were sandwiched between aluminum plates, and both sides of the obtained laminate were sandwiched between acrylic plates. In this way, a laminate for evaluating blocking resistance was obtained, having a laminate structure of acrylic plate / aluminum plate / polyvinyl chloride substrate / image recording sample (i.e., laminate of image / image recording substrate) / polyvinyl chloride substrate / aluminum plate / acrylic plate. The obtained laminate for evaluating blocking resistance was placed with the stacking direction facing the direction of gravity, and a 2.5 kg weight was placed on one of the acrylic plates of the laminate for evaluating blocking resistance in this state.The laminate was then left to stand at 70°C for 24 hours. After leaving it for 24 hours, the laminate for evaluating blocking resistance was peeled off at the interface between the image and the polyvinyl chloride substrate in contact with the image, and the state of transfer of the image to the polyvinyl chloride substrate in contact with the image was observed. The ratio (area %) of the area of ​​the image transferred to the polyvinyl chloride substrate to the total area of ​​the polyvinyl chloride substrate was measured. Based on the obtained results, the blocking resistance of the image was evaluated according to the following evaluation criteria. In the following evaluation criteria, the most excellent rank for image blocking resistance is "6".

[0292] -Evaluation criteria for blocking resistance- 6: No transcription. 5: The area of ​​the image transferred to the polyvinyl chloride substrate is greater than 0% and less than 20% of the area of ​​the polyvinyl chloride substrate. 4: The area of ​​the image transferred to the polyvinyl chloride substrate is more than 20% and not more than 40% of the area of ​​the polyvinyl chloride substrate. 3: The area of ​​the image transferred to the polyvinyl chloride substrate is more than 40% and not more than 60% of the area of ​​the polyvinyl chloride substrate. 2: The area of ​​the image transferred to the polyvinyl chloride substrate is more than 60% and not more than 80% of the area of ​​the polyvinyl chloride substrate. 1: The area of ​​the image transferred to the polyvinyl chloride substrate is greater than 80% of the area of ​​the polyvinyl chloride substrate.

[0293] <Evaluation of ink ejection properties> The ejection properties were evaluated using an inkjet ejection evaluation device (Drop Watcher, JetXpert) equipped with an inkjet head (product name "Samba G3L", manufactured by Fujifilm Corporation). First, the ink was ejected from the nozzles of the inkjet head to record a test image on inkjet photographic paper (Gasai, manufactured by Fujifilm Corporation). In this test image, the number of missing nozzles was counted and designated as N1. Next, the ink was continuously ejected from the nozzles of the inkjet head for 10 minutes. After this continuous ejection, the ink was ejected again from the nozzles of the inkjet head to record a test image on the inkjet printing paper. In this test image, the number of missing nozzles was counted and designated as N2. Based on these results, the increase in nozzle clogging due to continuous ejection for 10 minutes, ΔN=N2-N1, was calculated. The above operation was repeated three times, the average value of ΔN for the three times was calculated, and the ink ejection properties were evaluated according to the following evaluation criteria. In the following evaluation criteria, the most excellent ink ejection performance is ranked "5".

[0294] -Ink ejection properties- 5: Average ΔN is less than 1.2 4: Average ΔN is 1.2 or more and less than 1.6 3: Average ΔN is 1.6 or more and less than 2.0 2: Average ΔN is 2.0 or more and less than 3.0 1: Average ΔN is 3.0 or more

[0295] The evaluation results are shown in Tables 1 to 4. In Tables 1 to 4, the numerical value of the content of each component means mass % relative to the total amount of ink, and a blank cell means that the corresponding component is not contained. In Tables 1 to 4, the molecular weights of the polymerizable monomers and α-aminoketone initiators are shown, and the SP values ​​(MPa) of the polymerizable monomers are shown. 1 / 2The Tg of the polymerizable monomer is the Tg when the corresponding polymerizable monomer is made into a homopolymer. In Tables 1 to 4, "weighted average value of Tg" refers to the weighted average value (°C) of the glass transition temperature when all types of polymerizable monomers contained in the ink are treated as homopolymers.

[0296] [Table 1]

[0297] [Table 2]

[0298] [Table 3]

[0299] [Table 4]

[0300] As shown in Tables 1 to 4, in each example using an inkjet ink containing a polymerizable monomer and an α-aminoketone photopolymerization initiator having a molecular weight of 600 or more, and having a weighted average glass transition temperature of 0°C to 50°C when all of the contained polymerizable monomers are homopolymers, the lamination strength of the laminate and the blocking resistance of the image were excellent.

[0301] The results of each example and each comparative example were as follows. In Comparative Example 1, in which the weighted average value of the glass transition temperature was more than 50°C, the laminate strength was reduced. In Comparative Example 2, in which the weighted average value of the glass transition temperature was less than 0°C, the blocking resistance was reduced. In Comparative Example 3, which did not contain an α-aminoketone photopolymerization initiator with a molecular weight of 600 or more, but contained an α-aminoketone photopolymerization initiator with a molecular weight of less than 600, the blocking resistance decreased. The reason for this is thought to be that the curing effect near the surface of the ink film (i.e., image) due to the α-aminoketone photopolymerization initiator with a molecular weight of 600 or more could not be obtained.

[0302] The results of Examples 1 and 14 show that when the content mass ratio [α-aminoketone type photopolymerization initiator with a molecular weight of 600 or more / acylphosphine oxide type photopolymerization initiator] is 0.010 or more (Example 1), blocking resistance is further improved. The results of Examples 1 and 15 show that when the content mass ratio [α-aminoketone type photopolymerization initiator with a molecular weight of 600 or more / acylphosphine oxide type photopolymerization initiator] is 1.5 or less (Example 1), the lamination strength and blocking resistance are further improved.

[0303] The results of Examples 1 and 14 show that when the content mass ratio [α-aminoketone photopolymerization initiator with a molecular weight of 600 or more / sensitizing dye] is 0.010 or more (Example 1), blocking resistance is further improved. The results of Examples 1 and 16 show that when the content mass ratio [α-aminoketone type photopolymerization initiator with a molecular weight of 600 or more / sensitizing dye] is 2.0 or less (Example 1), the lamination strength and blocking resistance are further improved.

[0304] The results of Examples 1 and 13 show that when the polymerizable monomer contains an N-vinyl compound (Example 1), the laminate strength and blocking resistance are further improved.

[0305] The results of Examples 5 and 6 show that when the content mass ratio [N-vinyl compound / total polymerizable monomers] is 0.30 or more (Example 6), blocking resistance is further improved.

[0306] The results of Examples 1 and 11 to 13 show that when the content of monomer M1 having a Tg of 90°C or higher is 20% by mass to 50% by mass and the content of monomer M2 having a Tg of 30°C or lower is 35% by mass to 65% by mass (Example 1), the laminate strength and blocking resistance are further improved.

[0307] From the results of Examples 1 and 12, it was found that the polymerizable monomer had a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa. 1 / 2 ~21.5MPa 1 / 2 It can be seen that when the composition contains a monomer A having the formula (I) and the content mass ratio [monomer A / total polymerizable monomers] is 0.50 or more (Example 1), the laminate strength is further improved.

[0308] The results of Examples 1 and 7 show that when the content mass ratio [monomers having a molecular weight of 215 or less / total polymerizable monomers] is 0.80 or more (Example 1), the laminate strength is further improved.

[0309] The results of Examples 1 and 6 show that when the content mass ratio [monofunctional monomer / total polymerizable monomers] is 0.90 or more (Example 1), the laminate strength is further improved.

[0310] The results of Examples 1 to 3 show that blocking resistance is further improved when the resin T in the ink, which contains at least one selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms (a polysiloxane group in this example), contains a HEMA unit (a structural unit derived from hydroxyethyl methacrylate) (Examples 1 and 2).

[0311] [Examples 101 to 104] Examples 101 to 104 were carried out by changing the ink formulation and the evaluation conditions for the laminate strength in comparison with Example 1 described above. Details are shown below. For comparison, Table 5 also shows the results of evaluation of the ink of Example 1 under the same evaluation conditions as the inks of Examples 101 to 104.

[0312] <Ink Preparation> The cyan pigment dispersion liquid used in preparing the ink of Example 1 was mixed with the components listed in Table 5 other than the components contained in the cyan pigment dispersion liquid to obtain the contents listed in Table 5, thereby preparing an ink. In Table 5, "NPGPODA" as Monomer B is neopentyl glycol diacrylate, a difunctional acrylate. The meanings of other terms in Table 5 are the same as those in Tables 1 to 4.

[0313] <Preparation of image recording material> A polyvinyl chloride substrate (product name "PVC35phr", manufactured by Okamoto Corporation) was prepared as an image recording substrate. An inkjet recording device was prepared, which was equipped with an inkjet head (product name "Samba G3L", manufactured by Fujifilm Corporation) and a UV-LED irradiator (product name "G5A", manufactured by Kyocera Corporation) with a peak wavelength of 385 nm as an LED light source. The ink was applied twice onto the image recording substrate using the inkjet recording device (i.e., the first and second ink layers were applied one on top of the other), and an image was recorded. In detail, first, a rectangular area of ​​5 cm x 5 cm is printed with a resolution of 1200 dpi x 1200 dpi and an ink amount of 3.0 g / m 2 Under the conditions, ink was applied in a 100% solid image form to obtain a first ink layer. Next, the first ink layer was exposed to 45 mJ / cm from the LED light source "G5A." 2 The first ink layer was cured by irradiating it with UV (ultraviolet rays) under the conditions. Next, the same ink was applied onto the cured (i.e., UV-irradiated) first ink layer under the same conditions as for forming the first ink layer, to obtain a second ink layer. Next, the second ink layer was exposed to 1200 mJ / cm from the LED light source "G5A." 2The second ink layer was cured by irradiating it with UV (ultraviolet rays) under the conditions. In this manner, an image including the first ink layer and the second ink layer was recorded on the image recording substrate, and an image recorded matter including the image recording substrate and the image was obtained.

[0314] <Laminate strength evaluation (evaluation conditions changed)> A laminate was produced in the same manner as in Example 1, except that the thermocompression bonding conditions were changed from "130°C, pressure 2 MPa for 300 seconds, followed by pressure 10 MPa for 60 seconds" to "130°C, pressure 4 MPa for 60 seconds" (roughly weak thermocompression bonding conditions). The laminate strength of the obtained laminate was evaluated in the same manner as in Example 1. The results are shown in Table 5. The laminate strength evaluation in Table 5 (evaluation conditions changed) is stricter than the laminate strength evaluation in Tables 1 to 4, and is an evaluation that expresses the laminate strength as lower (because the thermocompression bonding conditions for obtaining the laminate body are weaker).

[0315] <Evaluation of blocking resistance> The blocking resistance of the image recorded matter obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 5.

[0316] <Evaluation of ink ejection properties> The ink ejection properties obtained above were evaluated in the same manner as in Example 1. The results are shown in Table 5.

[0317] [Table 5]

[0318] As shown in Table 5, Examples 101 to 104 in which the ink contained Monomer B, which was a bifunctional acrylate, had superior laminate strength compared to Example 1 in which the ink did not contain Monomer B. Among Examples 101 to 104, Examples 101 to 103, in which the content mass ratio [monomer B / total polymerizable monomers] was more than 0 and 0.10 or less, were particularly excellent in laminate strength.

Claims

1. a polymerizable monomer; an α-aminoketone photopolymerization initiator having a molecular weight of 600 or more; Contains the weighted average glass transition temperature of the homopolymer of the polymerizable monomer is 0°C to 50°C; Inkjet ink.

2. Further, an acylphosphine oxide type photopolymerization initiator is contained, a content mass ratio of the α-aminoketone type photopolymerization initiator having a molecular weight of 600 or more to the acylphosphine oxide type photopolymerization initiator is 0.010 to 1.5; The ink-jet ink of claim 1.

3. Further, it contains a sensitizing dye, the content mass ratio of the α-aminoketone photopolymerization initiator having a molecular weight of 600 or more to the sensitizing dye is 0.010 to 2.0; The ink-jet ink of claim 1.

4. The ink-jet ink of claim 1, wherein the polymerizable monomer comprises an N-vinyl compound.

5. the mass ratio of the amount of the N-vinyl compound to the total amount of the polymerizable monomers is 0.30 or more; The ink-jet ink of claim 4.

6. the polymerizable monomers include a monomer M1 having a glass transition temperature of 90°C or higher when made into a homopolymer, and a monomer M2 having a glass transition temperature of 30°C or lower when made into a homopolymer; the content of the monomer M1 relative to the total amount of the inkjet ink is 20% by mass to 50% by mass, and the content of the monomer M2 relative to the total amount of the inkjet ink is 35% by mass to 65% by mass; The ink-jet ink of claim 1.

7. The polymerizable monomer has a (meth)acryloyl group, a molecular weight of 215 or less, and a solubility parameter of 16.5 MPa. １／２ ~21.5 MPa １／２ and a monomer A, the mass ratio of the amount of the monomer A to the total amount of the polymerizable monomers is 0.50 or more; The ink-jet ink of claim 1.

8. the polymerizable monomer includes a compound having a molecular weight of 215 or less, a mass ratio of the amount of the compound having a molecular weight of 215 or less to the total amount of the polymerizable monomers is 0.80 or more; The ink-jet ink of claim 1.

9. the polymerizable monomer includes a monofunctional monomer, the mass ratio of the amount of the monofunctional monomer to the total amount of the polymerizable monomers is 0.90 or more; The ink-jet ink of claim 1.

10. the polymerizable monomer includes a compound having two or more (meth)acryloyl groups, a mass ratio of the amount of the compound having two or more (meth)acryloyl groups to the total amount of the polymerizable monomers is greater than 0 and not greater than 0.10; The ink-jet ink of claim 9.

11. the polymerizable monomer includes a monomer B which is a compound having two or more (meth)acryloyl groups and is a compound other than the monomer A; the mass ratio of the amount of the monomer B to the total amount of the polymerizable monomers is more than 0 and 0.10 or less; The ink-jet ink of claim 7.

12. The ink-jet ink according to claim 1 , further comprising a resin T containing at least one selected from the group consisting of a fluorohydrocarbon group, a polysiloxane group, and a hydrocarbon group having 12 or more carbon atoms.

13. The ink-jet ink according to claim 12, wherein the resin T contains structural units derived from hydroxyethyl methacrylate.

14. An image recording method, comprising a step of applying the inkjet ink according to any one of claims 1 to 13 onto an image recording substrate containing a polymer containing vinyl chloride as a constituent unit, by an inkjet recording method, to record an image.

15. a step of obtaining an image recording material comprising the image recording substrate and the image by the image recording method according to claim 14; a step of laminating the image recorded matter and a laminate substrate containing a polymer containing vinyl chloride as a structural unit, in such a manner that the image on the image recorded matter faces the laminate substrate, thereby obtaining a laminate; A method for manufacturing a laminate, comprising:

Images