Inkjet printing sheets

Abstract

The present invention addresses the problem of providing a sheet for inkjet printing, which is capable of ensuring sufficient printing density while suppressing printing unevenness by suppressing variation in the interference among dots in the surface of an ink-receiving layer. The present invention has solved this problem by a sheet for inkjet printing, said sheet having a multilayer structure that comprises an ink-receiving layer, a base material, an adhesive layer, and a release liner in this order, the release liner having a silicone-based release agent layer in a contact surface that is in contact with the adhesive layer, the ink-receiving layer being a cured layer of an ink-receiving layer forming composition that contains a specific energy ray curable compound (A) and a silicone-based leveling agent (B), and the water contact angle of the ink-receiving layer being 80° or less.

Description

[Technical Field]

[0001] The present invention relates to a sheet for inkjet printing. [Background technology]

[0002] Inkjet recording is a method of recording by ejecting ink droplets and depositing the ink onto inkjet printing media to form dots. Inkjet recording is rapidly gaining popularity due to its advantages, such as the ease with which high-quality full-color images can be obtained, its ease of high-speed operation, and its low running costs. Furthermore, with the widespread use of inkjet recording methods, various media for inkjet printing have been proposed, including, for example, an inkjet printing sheet having a laminated structure including an ink-receiving layer, a substrate, an adhesive layer, and a release liner in this order, which can be attached to glass or the like to be used as an indoor or outdoor decoration.

[0003] In this specification, the term "ink receiving layer" refers to a layer to which ink for inkjet printing is applied and which has the function of fixing the printed portion of the applied ink for inkjet printing.

[0004] In recent years, various ink-receiving layers have been proposed, including, for example, an ink-receiving layer containing a vinyl chloride resin and a vinyl acetate resin (see Patent Document 1, etc.), an ink-receiving layer containing polyvinyl butyral (see Patent Document 2, etc.), and the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-172877 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-130776 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors encountered the problem of print unevenness while conducting research and development on ink-receiving layers. Specifically, when ink droplets are ejected onto an ink-receiving layer using an inkjet recording method to form dots, the dots do not interfere with each other properly in some areas of the ink-receiving layer, resulting in uneven interference between dots within the ink-receiving layer, making the printing in those areas lighter than usual, and resulting in visible print unevenness when the entire printed area formed on the ink-receiving layer is observed. The present inventors have conducted extensive research to solve this problem, and have come across the problem that when trying to eliminate the print unevenness, the print density of the entire print area formed on the ink receiving layer decreases. Thus, there has been a problem in that it is difficult to simultaneously suppress printing unevenness in the ink receiving layer and ensure printing density.

[0007] The present invention has been made in consideration of such problems, and its objective is to provide an inkjet printing sheet that can suppress variations in interference between dots within the ink-receiving layer surface, thereby suppressing printing unevenness, while still ensuring sufficient printing density. [Means for solving the problem]

[0008] As a result of extensive research into solving the above problems, the inventors have found that the above problems can be solved by (1) making the ink-receiving layer a cured layer of a composition for forming an ink-receiving layer that contains a specific energy ray-curable compound and a silicone-based leveling agent, and (2) setting the water contact angle of the ink-receiving layer to 80° or less.

[0009] That is, the present invention relates to the following [1] to [7]. [1] A laminated structure including an ink-receiving layer, a substrate, a pressure-sensitive adhesive layer, and a release liner in this order; the release liner has a silicone-based release agent layer on the surface that comes into contact with the pressure-sensitive adhesive layer, the ink-receiving layer is a cured layer of an ink-receiving-layer-forming composition containing an energy ray-curable compound (A) and a silicone-based leveling agent (B); the energy ray-curable compound (A) is an ester of a polyol compound and (meth)acrylic acid, The ink-jet printing sheet, wherein the ink-receiving layer has a water contact angle of 80° or less. [2] The sheet for inkjet printing according to the above [1], wherein the energy ray-curable compound (A) further satisfies one or more of the following requirements (X1) to (X3): Requirement (X1): The ester is a partial ester. Requirement (X2): The polyol compound constituting the ester is an alkylene oxide modified product, provided that the alkylene group constituting the alkylene oxide modified product has 2 to 4 carbon atoms. Requirement (X3): The polyol compound constituting the ester has a glycerin skeleton. [3] The sheet for inkjet printing according to the above [1] or [2], wherein the composition for forming the ink-receiving layer further contains a filler (C). [4] The sheet for inkjet printing according to any one of the above [1] to [3], which is a wound body wound into a roll or a wound body wound around a core material. [5] A method of using the inkjet printing sheet according to any one of [1] to [4] above, to form a printed portion on the ink-receiving layer of the inkjet printing sheet using an inkjet printing ink. [6] A method for producing a printed matter, comprising the step of forming a printed portion on the ink-receiving layer of the ink-jet printing sheet according to any one of [1] to [4] above, using an ink-jet printing ink. [7] A printed matter having a printed portion printed with ink for inkjet printing on the ink-receiving layer of the sheet for inkjet printing according to any one of [1] to [4] above. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an inkjet printing sheet that can suppress variations in interference between dots within the ink-receiving layer surface, thereby suppressing printing unevenness, while still ensuring sufficient printing density. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing an example of an inkjet printing sheet according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing the stacked state of two inkjet printing sheets in the pretreatment carried out before evaluations (2) and (3) in the Examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] In this specification, the term "active ingredient (solid content)" refers to the components contained in the target composition excluding diluent solvents such as water and organic solvents. In this specification, (meth)acrylate means both methacrylate and acrylate, and the same applies to other similar terms. For example, (meth)acrylic acid means both methacrylic acid and acrylic acid, and a (meth)acryloyl group means both methacryloyl and acryloyl groups. In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." In this specification, the numerical values ​​in the examples are numerical values ​​that can be used as upper or lower limit values.

[0013] [Embodiments of the inkjet printing sheet of the present invention] The inkjet printing sheet of the present invention has a laminated structure including an ink-receiving layer, a substrate, a pressure-sensitive adhesive layer, and a release liner in this order. The release liner has a silicone-based release agent layer on the surface that comes into contact with the pressure-sensitive adhesive layer. The ink-receiving layer is a cured layer of a composition for forming an ink-receiving layer, which contains an energy ray-curable compound (A) and a silicone-based leveling agent (B). The energy ray-curable compound (A) is an ester of a polyol compound and (meth)acrylic acid. The ink-receiving layer has a water contact angle of 80° or less.

[0014] The present inventors have conducted extensive research to solve the above problems, and as a result have discovered that by incorporating a silicone-based leveling agent into the ink-receiving layer, it is possible to suppress variations in interference between dots within the surface of the ink-receiving layer, thereby suppressing print unevenness. However, it has been found that when a silicone-based leveling agent is added to the ink-receiving layer to suppress printing unevenness, the print density of the entire printed area formed on the ink-receiving layer decreases. In order to solve this problem, the present inventors have conducted further intensive research and have found that by forming the ink-receiving layer as a cured layer of a composition for forming an ink-receiving layer containing the above-mentioned specific energy ray-curable compound (A) and silicone-based leveling agent (B) and by adjusting the water contact angle of the ink-receiving layer to 80° or less, it is possible to ensure sufficient print density while suppressing print unevenness.

[0015] The mechanism by which the effects of the present invention are achieved is not clear, but is presumed to be as follows. That is, when an inkjet printing sheet having the above-described laminated structure is wound into a roll or wound around a core, minute amounts of silicone components migrate to the surface of the ink-receiving layer when the ink-receiving layer comes into contact with the back surface of the release liner. As a result, local variations in surface free energy occur on the surface of the ink-receiving layer. In areas where local variations in surface free energy occur, the wettability of dots to the ink-receiving layer is reduced compared to areas where no variations in surface free energy occur, resulting in less interference between dots than usual. This phenomenon inhibits the proper interference between dots that should occur, resulting in a pale printed area. It is presumed that the pale printed area in areas where surface energy variations occur and the standard dark printed area in areas where no variations in surface free energy occur result in visible print unevenness. Furthermore, this print unevenness can be reduced by incorporating a silicone-based leveling agent into the ink-receiving layer to suppress variations in interference between dots within the surface of the ink-receiving layer. It is believed that the effect of suppressing print unevenness is achieved by blending a silicone-based leveling agent into the ink-receiving layer, thereby preventing the mixture of areas with an excess of silicone components and areas with no silicone components at all within the ink-receiving layer surface. In other words, it is believed that the effect of suppressing print unevenness is achieved by homogenizing the surface free energy within the ink-receiving layer surface. On the other hand, when a silicone-based leveling agent is incorporated into the ink-receiving layer, the wettability of the entire ink-receiving layer is reduced, making it difficult for dots to wet and spread throughout the entire ink-receiving layer. As a result, the print density of the entire printed area formed on the ink-receiving layer is reduced. Therefore, the ink-receiving layer is formed as a cured layer of an ink-receiving layer-forming composition containing the specific energy ray-curable compound (A) and silicone-based leveling agent (B) described above, and the water contact angle of the ink-receiving layer is adjusted to 80° or less. This improves the wettability of the entire ink-receiving layer, making it easier for dots to wet and spread, ensuring sufficient print density while also fully suppressing print unevenness.

[0016] The inkjet printing sheet of the present invention will be described in detail below with respect to its configuration, the ink-receiving layer, substrate, adhesive layer, and release liner that constitute the inkjet printing sheet, the method for producing the inkjet printing sheet, and uses of the inkjet printing sheet.

[0017] [Composition of inkjet printing sheet] The inkjet printing sheet of the present invention has a laminated structure including an ink-receiving layer, a substrate, a pressure-sensitive adhesive layer, and a release liner in this order. A cross-sectional schematic diagram of one embodiment of the inkjet printing sheet of the present invention is shown in Figure 1. The inkjet printing sheet 1 shown in Figure 1 has a laminated structure including, in this order, an ink-receiving layer 2, a substrate 3, a pressure-sensitive adhesive layer 4, and a release liner 5. The release liner 5 also has a silicone-based release agent layer 5a and a support 5b, with the silicone-based release agent layer 5a in contact with the pressure-sensitive adhesive layer 4. 1, the ink-receiving layer 2, the substrate 3, the adhesive layer 4, and the release liner 5 are laminated directly on top of each other without any other layers in between. Therefore, the ink-receiving layer 2, the substrate 3, the adhesive layer 4, and the release liner 5 are the only components of the ink-receiving layer 2, the substrate 3, the adhesive layer 4, and the release liner 5. However, the inkjet printing sheet 1 is not necessarily limited to this form. For example, if necessary, another layer may be provided between the ink-receiving layer 2 and the substrate 3, or between the substrate 3 and the pressure-sensitive adhesive layer 4. An example of such another layer is an easy-adhesion layer. The silicone-based release agent layer 5a and the support 5b may be directly laminated as shown in Fig. 1, but another layer may be provided between the silicone-based release agent layer 5a and the support 5b as needed. Examples of such another layer include a sealing layer.

[0018] <Ink-receiving layer> In the inkjet printing sheet of the present invention, the ink-receiving layer is a cured layer of an ink-receiving layer-forming composition containing an energy ray-curable compound (A) and a silicone-based leveling agent (B), and has a water contact angle of 80° or less. This configuration makes it possible to suppress variations in interference between dots within the ink-receiving layer surface, thereby suppressing printing unevenness, while ensuring sufficient print density.

[0019] (Water contact angle of ink-receiving layer) In the present invention, the water contact angle of the ink-receiving layer must be 80° or less. If the water contact angle of the ink-receiving layer is 81° or more, the wettability of the ink-receiving layer cannot be sufficiently ensured, the dots do not wet and spread easily, and the print density decreases. Here, from the viewpoint of easily ensuring sufficient print density, the water contact angle of the ink-receiving layer is preferably 79° or less, and more preferably 78° or less. The lower limit of the water contact angle of the ink-receiving layer is not particularly limited, but is usually 58° or more, taking into consideration the structure of the ink-receiving layer, for example.

[0020] In this specification, the water contact angle of the ink-receiving layer refers to a value measured by the method described in the Examples below. The portion of the ink-receiving layer where the water contact angle is measured is the portion where the ink for inkjet printing is applied.

[0021] The water contact angle of the ink-receiving layer can be adjusted by adjusting the type and content of the energy ray-curable compound (A) and silicone-based leveling agent (B) contained in the composition for forming the ink-receiving layer. Hereinafter, the energy ray curable compound (A) and the silicone leveling agent (B) will be described in detail, taking into consideration the method for adjusting the water contact angle of the ink-receiving layer.

[0022] (Energy ray curable compound (A)) In the present invention, the composition for forming the ink-receiving layer contains an energy ray-curable compound (A). If the composition for forming the ink-receiving layer does not contain the energy ray-curable compound (A), it becomes difficult to adjust the water contact angle of the ink-receiving layer to 80° or less, making it difficult to ensure sufficient print density. In addition, it becomes easy to increase the surface hardness of the ink-receiving layer, making it easier to prevent scratches during application or use. Here, the term "energy ray-curable compound" refers to a compound that is cured (polymerized) by irradiation with energy rays. Therefore, the ink-receiving layer contains a polymer (resin) derived from the energy ray-curable compound (A). Furthermore, "energy rays" refers to electromagnetic waves or charged particle rays that have an energy quantum, examples of which include ultraviolet rays and electron beams, with ultraviolet rays being preferred.

[0023] In the present invention, the energy ray-curable compound (A) is an ester of a polyol compound and (meth)acrylic acid. If the energy ray-curable compound (A) is a compound other than an ester of a polyol compound and (meth)acrylic acid, it becomes difficult to adjust the water contact angle of the ink-receiving layer to 80° or less, and it becomes difficult to ensure sufficient print density. The energy ray-curable compound (A) may be used alone or in combination of two or more.

[0024] The energy ray-curable compound (A) may be a polymerizable compound having one or more (meth)acryloyl groups in one molecule. Here, from the viewpoint of making it easier to improve the effects of the present invention, the energy ray-curable compound (A) preferably has two or more (meth)acryloyl groups in one molecule, and more preferably has 2 to 6 (meth)acryloyl groups.

[0025] The polyol compound constituting the energy ray-curable compound (A) is preferably a dihydric to decahydric polyol, more preferably a trihydric to hexahydric polyol. The polyol compound may also be an alkylene oxide modified product. Therefore, the polyol compound may also be preferably an alkylene oxide modified product of a dihydric to decahydric polyol, more preferably an alkylene oxide modified product of a trihydric to hexahydric polyol. The alkylene group constituting the alkylene oxide modified product preferably has 2 to 4 carbon atoms, more preferably 2 to 3 carbon atoms, and even more preferably 2 carbon atoms.

[0026] Specific examples of preferred polyol compounds include polyols such as trimethylolethane, trimethylolpropane, trimethylolbutane, ditrimethylolpropane, tritrimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, polyglycerin (a glycerin polymer, preferably a dimer to decamer of glycerin, more preferably a dimer to hexamer of glycerin, and even more preferably a trimer to pentamer of glycerin), 1,3,5-pentanetriol, sorbitol, adonitol, arabitol, xylitol, and mannitol; and alkylene oxide modified products (preferably ethylene oxide modified products) of these polyols.

[0027] Here, from the viewpoint of making it easier to adjust the water contact angle of the ink-receiving layer to 80° or less, the energy ray-curable compound (A) preferably satisfies one or more of the following requirements (X1) to (X3). Requirement (X1): The ester is a partial ester. Requirement (X2): The polyol compound constituting the ester is an alkylene oxide modified product, provided that the alkylene group constituting the alkylene oxide modified product has 2 to 4 carbon atoms. Requirement (X3): The polyol compound constituting the ester has a glycerin skeleton.

[0028] Esters of polyol compounds and (meth)acrylic acid that satisfy the above requirement (X1) tend to have a high hydroxyl value and high hydrophilicity, making it easy to adjust the water contact angle of the ink-receiving layer to 80° or less. From the viewpoint of further enhancing hydrophilicity and making it easier to adjust the water contact angle of the ink-receiving layer to 80° or less, the partial ester of a polyol compound and (meth)acrylic acid preferably has a hydroxyl value of 50 mgKOH / g or more, more preferably 70 mgKOH / g or more, and even more preferably 80 mgKOH / g or more. In this specification, the hydroxyl value means a value measured in accordance with JIS K0070:1992.

[0029] Esters of polyol compounds and (meth)acrylic acid that satisfy the above requirement (X2) tend to be highly hydrophilic, and therefore it is easy to adjust the water contact angle of the ink-receiving layer to 80° or less. The ester satisfying the above requirement (X2) may be a complete ester or a partial ester. When the ester satisfying the above requirement (X2) is a partial ester, it also satisfies the above requirement (X1). The number of carbon atoms in the alkylene group constituting the alkylene oxide modified product is preferably 2 to 4, more preferably 2 to 3, and even more preferably 2. The number (molar number) of alkylene oxides in one molecule is not limited, but from the viewpoint of increasing the hydrophilicity of the ester of the polyol compound and (meth)acrylic acid and making it easier to adjust the water contact angle of the ink-receiving layer to 80° or less, it is preferably 4.0 or more, more preferably 5 or more, and even more preferably 6 or more.

[0030] Esters of polyol compounds and (meth)acrylic acid that satisfy the above requirement (X3) tend to be highly hydrophilic, and therefore it is easy to adjust the water contact angle of the ink-receiving layer to 80° or less. The ester satisfying the above requirement (X3) may be a complete ester or a partial ester. When the ester satisfying the above requirement (X3) is a partial ester, it also satisfies the above requirement (X1). The polyol compound having a glycerin skeleton refers to glycerin or polyglycerin. As mentioned above, polyglycerin refers to a glycerin polymer, preferably a dimer to decamer of glycerin, more preferably a dimer to hexamer of glycerin, even more preferably a trimer to pentamers of glycerin, and even more preferably a tetramer of glycerin.

[0031] In one embodiment of the present invention, the content of the energy ray-curable compound (A) is appropriately adjusted so that the water contact angle of the ink-receiving layer can be adjusted to 80° or less. Increasing the content of the energy ray-curable compound (A) in the composition for forming an ink-receiving layer decreases the water contact angle of the ink-receiving layer. Conversely, decreasing the content of the energy ray-curable compound (A) in the composition for forming an ink-receiving layer increases the water contact angle of the ink-receiving layer. In light of this tendency, the content of the energy ray-curable compound (A) is adjusted so that the water contact angle of the ink-receiving layer can be adjusted to 80° or less, taking into account the balance with the amount of the silicone-based leveling agent (B).

[0032] (Silicone leveling agent (B)) In the present invention, the ink-receiving layer-forming composition and the ink-receiving layer contain a silicone-based leveling agent (B). If the ink-receiving layer-forming composition and the ink-receiving layer do not contain a silicone-based leveling agent (B), print unevenness cannot be suppressed. The silicone leveling agent (B) is presumed to have the effect of suppressing the partial disturbance of the surface free energy on the surface of the ink-receiving layer caused by the silicone component migrating from the backside of the release liner to the ink-receiving layer, homogenizing the surface free energy within the ink-receiving layer surface, and suppressing variations in interference between dots within the ink-receiving layer surface.This effect is thought to suppress printing unevenness.

[0033] The silicone leveling agent (B) is a compound having a siloxane skeleton, and specifically includes one or more compounds selected from compounds having a siloxane skeleton and an organic functional group, compounds having a siloxane skeleton and an organic modified group, etc. The organic modified group refers to a group in which a part of the organic functional group is substituted with another group. Specific examples of the silicone leveling agent (B) include polyether-modified silicone oils (manufactured by Dow-Toray Industries, Inc.) such as DOWSIL (registered trademark) BY16-036 Fluid, SH28 Paint Additive, SF8428 Fluid, 501W Additive, L-7001 Fluid, FZ-2104 Fluid, L-7002 Fluid, and SF8427 Fluid; alkyl-modified silicone oils (manufactured by Dow-Toray Industries, Inc.) such as DOWSIL (registered trademark) SF8416 Fluid, BY16-846 Fluid, SH203 Fluid, and 56 Additive; carboxyl-modified silicone oils (manufactured by Dow-Toray Industries, Inc.) such as DOWSIL (registered trademark) BY-16-880 and BY16-750 Fluid; XIAMETER (registered trademark) OFX-8417 Fluid, DOWSIL (registered trademark) BY-16-849 Fluid, and XIAMETER (registered trademark) BY-16-849 Fluid. Examples of suitable silicone oils include amino-modified silicone oils (manufactured by Dow-Toray Industries, Inc.) such as FZ-3785 Fluid, 16-872 Fluid, and 16-853U Fluid; and epoxy-modified silicone oils (manufactured by Dow-Toray Industries, Inc.) such as DOWSIL (registered trademark) SF8413 Fluid, SF8411 Fluid, BY16-839 Fluid, FZ-3736 Fluid, SF8421 EG Fluid, BY16-870 Fluid, BY16-876 Fluid, BY16-869 Fluid, and BY16-760 Fluid. Among these, polyether-modified silicone oil is more preferable. The silicone leveling agent (B) may be used alone or in combination of two or more kinds.

[0034] In one embodiment of the present invention, the content of the silicone-based leveling agent (B) in the composition for forming the ink-receiving layer is appropriately adjusted so as to suppress printing unevenness and adjust the water contact angle of the ink-receiving layer to 80° or less. Increasing the content of the silicone-based leveling agent (B) in the composition for forming an ink-receiving layer increases the water contact angle of the ink-receiving layer. Conversely, decreasing the content of the silicone-based leveling agent (B) in the composition for forming an ink-receiving layer decreases the water contact angle of the ink-receiving layer. In light of this tendency, the content of the silicone-based leveling agent (B) is adjusted so that the water contact angle of the ink-receiving layer can be adjusted to 80° or less, from the perspective of balancing with the effect of the energy ray-curable compound (A) in improving the hydrophilicity of the ink-receiving layer. The content of the silicone-based leveling agent (B) is, for example, preferably 0.01 to 0.06 parts by mass, more preferably 0.02 to 0.05 parts by mass, relative to 100 parts by mass of the energy ray-curable compound (A). 2 An example of the content of the silicone-based leveling agent (B) per unit area is preferably 0.12 mg / m 2 ~1.0mg / m 2 , more preferably 0.27 mg / m 2 ~0.75mg / m 2 is.

[0035] (Filler (C)) In one embodiment of the present invention, the composition for forming an ink-receiving layer and the ink-receiving layer preferably further contain a filler (C). By including the filler (C) in the composition for forming the ink-receiving layer and the ink-receiving layer, the slipperiness of the surface of the ink-receiving layer can be improved, making it easier to improve the transportability of the ink-jet printing sheet. Here, "improved transportability" means improving the slipperiness between inkjet printing sheets and between the inkjet printing sheet and the device (roller or cylinder). This allows the inkjet printing sheet to be smoothly wound and unwound, and makes it easier to prevent the sheet from being wrinkled or scratched, or to prevent misalignment of the printing position.

[0036] Examples of the filler (C) include silica, alumina, titania, and zirconia oxide, with silica being preferred since it is less likely to impair the transparency of the ink-receiving layer.

[0037] The particle size of the filler (C) is preferably from 10 nm to less than 1 μm, more preferably from 10 nm to 500 nm, and even more preferably from 10 nm to 100 nm. When the particle size of the filler (C) is within the above range, the slipperiness of the surface of the ink-receiving layer is improved, which makes it easier to improve the transportability of the ink-jet printing sheet, and the transparency of the ink-receiving layer is also less likely to be impaired. The particle size of the filler (C) is an average primary particle size converted from the specific surface area by the BET method.

[0038] The filler (C) may be in the form of a dry powder, but from the viewpoint of dispersion stability, it is preferable to use a colloidal solution obtained by dispersing the filler in an organic solvent.

[0039] The filler (C) may be used alone or in combination of two or more kinds.

[0040] In one embodiment of the present invention, the content of the filler (C) in the composition for forming the ink-receiving layer is not particularly limited, but from the viewpoint of improving the slipperiness of the surface of the ink-receiving layer and facilitating the improvement of the transportability of the inkjet printing sheet, and from the viewpoint of making it difficult to impair the transparency of the ink-receiving layer, the content is preferably 20 to 500 parts by mass, more preferably 30 to 300 parts by mass, even more preferably 40 to 200 parts by mass, and even more preferably 50 to 150 parts by mass per 100 parts by mass of the energy ray-curable compound (A).

[0041] (Photopolymerization initiator (D)) In one embodiment of the present invention, the ink-receiving layer-forming composition and the ink-receiving layer preferably contain a photopolymerization initiator (D). When the ink-receiving layer-forming composition contains the photopolymerization initiator (D) together with the energy ray-curable compound (A), energy ray curing by ultraviolet rays or the like can be facilitated. As the photopolymerization initiator (D), any general compound having the function of facilitating the progress of energy ray curing by ultraviolet rays or the like can be used without particular limitation. Examples of such compounds include 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methylpropan-1-one. The photopolymerization initiator (D) may be used alone or in combination of two or more.

[0042] In one embodiment of the present invention, the content of the photopolymerization initiator (D) in the composition for forming an ink-receiving layer is not particularly limited, but is preferably 0.1 to 10 parts by mass per 100 parts by mass of the energy ray-curable compound (A).

[0043] (Other additives) In one embodiment of the present invention, the composition for forming the ink-receiving layer may or may not contain other components other than the energy ray-curable compound (A), the silicone-based leveling agent (B), the filler (C), and the photopolymerization initiator (D), as long as the water contact angle of the ink-receiving layer can be adjusted to 80° or less. For example, the composition for forming the ink-receiving layer may or may not contain an energy ray-curable compound (A') other than the energy ray-curable compound (A), as long as the water contact angle of the ink-receiving layer can be adjusted to 80° or less.

[0044] <Base material> The ink jet printing sheet of the present invention has a substrate. The substrate supports the inkjet printing sheet and also functions as a support for supporting the printing portion formed on the ink-receiving layer.

[0045] The substrate is not particularly limited, but is preferably a resin sheet. By using a resin sheet as the substrate, the inkjet printing sheet can be improved in rigidity, flexibility, etc., and the inkjet printing sheet can be easily handled. This is also advantageous from the viewpoint of reducing the production cost and weight of the inkjet printing sheet.

[0046] Examples of resins that may be used to make the resin sheet include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene and polypropylene; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; urethane resins such as polyurethane and acrylic-modified polyurethane; polymethylpentene; polysulfone; polyether ether ketone; polyether sulfone; polyphenylene sulfide; polyimide resins such as polyetherimide and polyimide; polyamide resins; acrylic resins; fluorine-based resins, etc. Among these, from the viewpoint of easily improving adhesion to the ink-receiving layer, polyester-based resins and polyolefin-based resins are preferred, polyester-based resins are more preferred, and polyethylene terephthalate is even more preferred.

[0047] The resin sheet may be composed of only one type of resin, or may be composed of two or more types of resin. When the resin sheet is composed of two or more types of resin, it is preferably a multi-layered body. Furthermore, the uppermost layer of the multi-layered body (the layer in contact with the ink-receiving layer) is preferably a polyester-based resin, more preferably polyethylene terephthalate, from the viewpoint of easily improving adhesion to the ink-receiving layer. The resin sheet may be unstretched, or may be stretched uniaxially, such as longitudinally or transversely, or biaxially.

[0048] In addition, the resin sheet may contain, together with these resins, additives for the substrate, such as a surface conditioner, a plasticizer, an ultraviolet absorber, a light stabilizer, and a colorant. The content of the additive for the substrate is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, based on the total amount of the substrate.

[0049] The thickness of the substrate is not particularly limited, but is preferably 15 μm to 300 μm, and more preferably 30 μm to 200 μm.

[0050] <Adhesive layer> The inkjet printing sheet of the present invention has a pressure-sensitive adhesive layer. By having a pressure-sensitive adhesive layer, the inkjet printing sheet of the present invention can be suitably used as a pressure-sensitive adhesive sheet.

[0051] The adhesive constituting the adhesive layer is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, etc. When the inkjet printing sheet is used for window displays, etc., the adhesive layer may be formed from an acrylic adhesive from the viewpoint of weather resistance, etc. Furthermore, when removability from the adherend is required, the adhesive layer may be formed from a urethane adhesive. The pressure-sensitive adhesive layer may contain other components, such as an ultraviolet absorber, a tackifier, an antioxidant, a light stabilizer, a softener, a silane coupling agent, a filler, etc. These may be used alone or in combination of two or more.

[0052] The thickness of the adhesive layer is not particularly limited, but from the viewpoint of improving the handleability when using the inkjet printing sheet as an adhesive sheet, it is preferably 5 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 15 μm to 50 μm.

[0053] <Release liner> The ink jet printing sheet of the present invention has a release liner. By covering the adhesive surface of the pressure-sensitive adhesive layer of the inkjet printing sheet of the present invention with a release liner, the adhesive surface of the pressure-sensitive adhesive layer can be suitably protected during transportation and storage of the inkjet printing sheet.

[0054]

[0013] In the inkjet printing sheet of the present invention, the release liner has a silicone-based release agent layer. When the release liner is rolled or wound, a very small amount of the silicone component may migrate to the back surface of the release liner. Therefore, when the inkjet printing sheet having the above-described laminated structure is rolled or wound, the very small amount of the silicone component present on the back surface of the release liner may migrate to the ink-receiving layer. Silicone components that migrate from the back surface of the release liner to the ink-receiving layer cause localized disturbances in the surface free energy of the ink-receiving layer. As a result, interference between dots within the ink-receiving layer varies, resulting in print unevenness. However, according to the present invention, by incorporating a silicone-based leveling agent (B) into the ink-receiving layer-forming composition and the ink-receiving layer, it is possible to suppress localized disturbances in the surface free energy of the ink-receiving layer, homogenize the surface free energy of the ink-receiving layer, suppress variation in interference between dots within the ink-receiving layer, and thereby suppress print unevenness. Furthermore, by making the water contact angle of the ink-receiving layer 80° or less, the decrease in print density that occurs when the silicone-based leveling agent (B) is blended can be suppressed, and sufficient print density can be ensured.

[0055] As the silicone-based release agent layer that constitutes the release liner, any material that is generally used for release liners can be used without any particular limitation.

[0056] The support constituting the release liner may be a sheet substrate or a paper substrate that is generally used for release liners. Examples of the sheet substrate include polyester resins such as polyethylene terephthalate, and polyolefin resins such as polyethylene resin and polypropylene resin. Examples of the paper substrate include fine paper, kraft paper, and glassine paper.

[0057] The thickness of the release liner is not particularly limited, but is preferably 10 μm to 150 μm, more preferably 20 μm to 130 μm, and even more preferably 30 μm to 120 μm.

[0058] [Method of manufacturing inkjet printing sheet] The method for producing the inkjet printing sheet of the present invention is not particularly limited, and may be appropriately selected depending on the configuration of the inkjet printing sheet.

[0059] A preferred method for forming the ink-receiving layer is to apply a composition for forming an ink-receiving layer containing an energy ray-curable compound (A) and a silicone-based leveling agent (B) to one surface of a substrate to form a coating film, and then dry and cure the coating film. As described above, the composition for forming the ink-receiving layer preferably further contains a filler (C) and a photopolymerization initiator (D). In order to improve the workability of application to the substrate, the composition for forming the ink-receiving layer is preferably further diluted with a dilution solvent to form a solution.

[0060] Examples of dilution solvents include organic solvents such as methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol. The concentration of the active ingredients (solid content) in the solution of the composition for forming the ink-receiving layer is preferably 10 to 50% by mass.

[0061] Examples of methods for applying the solution of the composition for forming the ink-receiving layer include bar coating, gravure coating, roll coating, knife coating, and die coating.

[0062] The heating conditions for drying the coating film are, for example, a drying temperature of 60°C to 120°C and a drying time of 30 seconds to 3 minutes.

[0063] After the coating film is dried, it is irradiated with energy rays (preferably ultraviolet rays) to cure (polymerize) the energy ray-curable compound (A). When ultraviolet rays are used as energy rays, the irradiation conditions for ultraviolet rays are 5 to 1200 mJ / cm in cumulative irradiation amount (cumulative light amount). 2 is preferred, and 30 to 500 mJ / cm 2 is more preferred. The ultraviolet light can be irradiated using, for example, a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp, an LED, or the like as an ultraviolet light source.

[0064] The pressure-sensitive adhesive layer of the inkjet printing sheet of one embodiment of the present invention is formed on the other side of the substrate, on which the ink-receiving layer is not formed. The pressure-sensitive adhesive layer is formed, for example, by applying a composition for forming a pressure-sensitive adhesive layer (composition for forming a pressure-sensitive adhesive layer) to the other surface of the substrate, and then laminating a release liner on the pressure-sensitive adhesive layer. Alternatively, the pressure-sensitive adhesive layer may be formed by applying a composition for forming a pressure-sensitive adhesive layer to the release surface of the release liner (surface of the silicone-based release agent layer), and then the pressure-sensitive adhesive layer may be attached to the other surface of the substrate. The method for applying the composition for forming the pressure-sensitive adhesive layer is the same as the method for applying the composition for forming the ink-receiving layer described above.

[0065] [Inkjet printing ink] The inkjet printing sheet of the present invention is effective in ensuring sufficient print density while suppressing print unevenness in inkjet printing using ultraviolet-curable ink or latex ink, which does not or is unlikely to penetrate into the ink-receiving layer, and is particularly effective in ensuring sufficient print density while suppressing print unevenness in inkjet printing using ultraviolet-curable ink.

[0066] <UV-curable ink> The UV-curable ink is substantially free of organic solvents and is cured by exposure to UV light. The UV-curable ink contains a photopolymerizable monomer, a colorant that is a pigment or dye, and a photopolymerization initiator that initiates a polymerization reaction. In one aspect of the present invention, from the viewpoint of further improving the adhesion between the ink-receiving layer and the printed portion, the ultraviolet-curable ink preferably contains an acrylic monomer.

[0067] (Photopolymerizable monomer) Examples of the photopolymerizable monomer include monofunctional acrylates, difunctional acrylates, polyfunctional acrylates, and mixtures thereof. Note that the photopolymerizable monomer may also be an acrylic monomer formed by combining one or more of these acrylates. Examples of monofunctional acrylates include hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, phenol EO-modified (n=2) acrylate, 2-ethylhexyl EO-modified (n=2) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, isobornyl acrylate, and acryloylmorpholine. Examples of bifunctional acrylates include hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol hydroxypivalate diacrylate, and bisphenol A EO-modified (n=4) diacrylate. Examples of polyfunctional acrylates include trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane PO-modified (n=3) triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0068] (coloring agent) UV curable inks typically contain a colorant. As the colorant, various dyes, various pigments, etc. can be used.

[0069] (Photopolymerization initiator) Photopolymerization initiators generally initiate a polymerization reaction upon irradiation with ultraviolet light. Such photopolymerization initiators may be, for example, a single photopolymerization initiator or a mixture of multiple photopolymerization initiators, or a combination of a photopolymerization initiator and a photosensitizer. For example, a combination of multiple photopolymerization initiators with different excitation wavelengths or a combination to which a photosensitizer has been added may be used.

[0070] (Other ingredients) As other components, for example, various conventionally known components such as dispersants, stabilizers, surfactants, etc. may be further blended as required.

[0071] <Latex ink> Latex ink contains a liquid dispersion medium and a dispersoid made of a material containing at least a resin, which is dispersed (emulsified and / or suspended) in the dispersion medium.

[0072] (resin) The resin contained in the latex ink is not particularly limited, but examples include vinyl resins, acrylic resins, styrene resins, alkyd resins, polyester resins, polyurethane resins, epoxy resins, phenoxy resins, polyolefin resins, and modified resins thereof (for example, modified resins modified to be water-soluble), and one or more selected from these can be used in combination.

[0073] (dispersion medium) Latex ink contains water as a dispersion medium.

[0074] (coloring agent) Latex inks typically contain a colorant. As the colorant, various dyes, various pigments, etc. can be used.

[0075] (Other ingredients) The latex ink may contain components other than those already described (other components). Examples of such components include dispersants, antifungals, anticorrosives, pH adjusters, surfactants, plasticizers, ultraviolet absorbers, and light stabilizers.

[0076] [Printing method] The printed portion using inkjet printing ink is formed by applying inkjet printing ink onto the ink-receiving layer of the inkjet printing sheet by an inkjet method. Examples of inkjet methods include a piezo method and a thermal jet method. When applying the ultraviolet curable ink as an inkjet printing ink, the amount of ultraviolet irradiation to the ultraviolet curable ink is not particularly limited, but is preferably 40 J / m 2 ~400J / m 2 is. When applying latex ink as inkjet printing ink, the heating temperature of the latex ink is not particularly limited, but is preferably 40°C to 90°C. By the above method, a printed matter can be obtained on the ink-receiving layer of the ink-jet printing sheet, having a printed portion in which printing unevenness caused by the ink-jet printing ink is suppressed while ensuring sufficient print density. The inkjet printing sheet of the present invention can suppress print unevenness, especially in inkjet printing with a reduced ink amount. Specifically, even when the total ink amount is 10% to 70% (preferably 10% to 50%, more preferably 15% to 40%), it is possible to form a printed portion with sufficient print density while suppressing print unevenness.

[0077] [Uses of inkjet printing sheets] The ink-jet printing sheet of the present invention is used for printing using ink-jet printing ink. Therefore, according to the present invention, there is provided a method of using the inkjet printing sheet to form a printed portion on the ink-receiving layer of the inkjet printing sheet using inkjet printing ink. The present invention also provides a method for producing a printed matter, which comprises the step of forming a printed portion on the ink-receiving layer of the ink-jet printing sheet using ink for ink-jet printing. Furthermore, according to the present invention, there is provided a printed matter having a printed portion printed with ink for ink-jet printing on the ink-receiving layer of the ink-jet printing sheet.

[0078] Inkjet printing using ultraviolet-curable ink and latex ink is employed in the method of use, method of producing a printed matter, and printed matter of one embodiment of the present invention. Because the inkjet printing sheet of the present invention is used in the method of use, method of producing a printed matter, and printed matter of the present invention, it is possible to form a printed portion that ensures sufficient print density while suppressing print unevenness, even in inkjet printing using ultraviolet-curable ink and latex ink, which do not or are unlikely to penetrate into the ink-receiving layer. Of the ultraviolet curable ink and latex ink, the ultraviolet curable ink can be particularly preferably used.

[0079] Furthermore, in the method of use, method of producing a printed matter, and printed matter according to one embodiment of the present invention, the total amount of ink used in inkjet printing is not particularly limited, but the effects of the present invention are particularly likely to be achieved when the total amount of ink is preferably 10% to 70%, more preferably 10% to 50%, and even more preferably 15% to 40%. According to the method of use, method of producing a printed matter, and printed matter of one aspect of the present invention, even with the above-mentioned ink amount, sufficient print density is ensured while suppressing print unevenness, which is particularly useful when printing with shading or gradation. [Example]

[0080] The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

[0081] [Examples 1 to 12, Comparative Examples 1 to 4] Inkjet printing sheets of Examples 1 to 12 and Comparative Examples 1 to 4 were prepared by the following procedure.

[0082] <Preparation of composition for forming ink-receiving layer> A composition for forming an ink-receiving layer having the formulation shown in Table 1 was prepared. Details of the raw materials used in preparing the composition for forming the ink-receiving layer are shown below.

[0083] (Energy ray curable compound (A)) "Compound 1": Ethylene oxide-modified hexafunctional polyglycerin acrylate (The polyol compound is an ethylene oxide-modified polyglycerin (a tetramer of glycerin), and is a complete ester with six acryloyl groups. The number of moles of ethylene oxide is 6.) "Compound 2": Ethylene oxide-modified dipentaerythritol hexaacrylate (The polyol compound is an ethylene oxide-modified dipentaerythritol, and is a complete ester with six acryloyl groups. The number of moles of ethylene oxide is 12.) "Compound 3": Ethylene oxide-modified pentaerythritol tetraacrylate (The polyol compound is an ethylene oxide-modified pentaerythritol, and is a complete ester having four acryloyl groups. The number of moles of ethylene oxide is 35.) "Compound 4": Dipentaerythritol pentaacrylate (The polyol compound is dipentaerythritol, and it is a partial ester having five acryloyl groups. The hydroxyl value is 90 mg KOH / g.) "Compound 5": Glycerin diacrylate (a partial ester containing glycerin as a polyol compound and two acryloyl groups. The hydroxyl value is 240 mg KOH / g.) "Compound 6": Ethylene oxide-modified sorbitol diacrylate (a polyol compound is an ethylene oxide-modified sorbitol, and is a partial ester having two acryloyl groups. The number of moles of ethylene oxide is 6.) "Compound 7": Dipentaerythritol hexaacrylate (The polyol compound is dipentaerythritol, and it is a complete ester having six acryloyl groups. The hydroxyl value is 10 mg KOH / g.)

[0084] The above compounds 1 to 7 are all esters of a polyol compound and (meth)acrylic acid. The compound 1 further satisfies the above requirement (X2) and the above requirement (X3). The above compound 2 further satisfies the above requirement (X2). The compound 3 further satisfies the above requirement (X2). The compound 4 further satisfies the above requirement (X1). The compound 5 further satisfies the above requirement (X1) and the above requirement (X3). Compound 6 further satisfies the above requirement (X1) and the above requirement (X2).

[0085] (Silicone leveling agent (B)) Polyether modified silicone oil

[0086] (Filler (C)) Organosilica sol (particle size 70-100nm)

[0087] (Photopolymerization initiator (D)) 2-Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methylpropan-1-one

[0088] The compositions for forming the ink-receiving layer having the compositions shown in Table 1 (amounts of active ingredients converted into active ingredients) were each diluted with a dilution solvent (ethyl acetate) to form coating liquids with an active ingredient concentration of 30% by mass, and used to prepare sheets for inkjet printing.

[0089] (Preparation of inkjet printing sheets) The ink-receiving layer-forming composition thus prepared was applied to one surface of a polyethylene terephthalate substrate (thickness: 50 μm) using a bar coater so that the film thickness after drying would be 2.5 μm. Next, the solvent contained in the ink-receiving layer-forming composition applied to the substrate was removed by heating at 70°C for 1 minute using a hot air dryer, and then ultraviolet light having a peak wavelength of 365 nm was applied at an integrated light intensity of 90 mJ / cm. 2 The ink-receiving layer was formed by irradiation. Next, a release liner (thickness: 50 μm) with a silicone-based release agent layer on one side of a polyethylene terephthalate sheet was prepared, and an acrylic adhesive was applied to the silicone-based release agent layer side so that the film thickness after drying would be 20 μm.The coating was then heated at 90°C for 1 minute using a hot air dryer to remove the solvent contained in the coating liquid, forming an acrylic adhesive layer. Thereafter, the acrylic pressure-sensitive adhesive layer formed on the release liner was attached to the surface of the substrate opposite to the ink-receiving layer to obtain a sheet for ink-jet printing.

[0090] <Evaluation> The evaluations described in (1) to (4) below were carried out. In addition, when the following evaluations (2) and (3) were performed, the pretreatment described below was performed assuming that the ink-receiving layer would come into contact with the back surface of the release liner due to the ink-jet printing sheet being rolled up. That is, two identical ink-jet printing sheets were prepared, and as shown in FIG. 2, they were stacked so that the surface of the ink-receiving layer 2x of one ink-jet printing sheet 1x came into contact with the back surface of the release liner 5y of the other ink-jet printing sheet 1y, and the sheets were subjected to a pressure of 20 kg / cm in an environment at a temperature of 70°C. 2 The mixture was left standing for 12 hours under a pressure of 1.0 MPa.

[0091] (1) Measurement of water contact angle of ink-receiving layer The water contact angle was measured using an automatic contact angle meter DSA100S (manufactured by KRUSS) for the ink-receiving layer (the portion of the ink-receiving layer to which the ink for ink-jet printing is applied) of the ink-jet printing sheets of Examples 1 to 12 and Comparative Examples 1 to 4. The measurement was carried out in an atmosphere of 23°C and 50% RH, and 2 μL of water was dropped and the static contact angle was calculated by the θ / 2 method.

[0092] (2) Evaluation of printing unevenness On the surface of the ink-receiving layer of the inkjet printing sheets of Examples 1 to 12 and Comparative Examples 1 to 4, printing was carried out by the inkjet method using an inkjet printer (Mimaki Engineering Co., Ltd., UCJV300) with ultraviolet-curable ink (Mimaki Engineering Co., Ltd., LUS-170), with 5% each of CMYK, for a total ink amount of 20%, to form a printed portion. After printing was completed, the entire printed surface was visually observed and evaluated according to the following criteria. A: No unevenness in printing is observed across the entire printed surface. B: There is slight unevenness in printing on some parts of the printed surface, but there is no major problem with the print quality. C: There are noticeable differences in shading across the entire printed surface, and the print is very uneven.

[0093] (3) Evaluation of print density On the surface of the ink-receiving layer of the ink-jet printing sheets of Examples 1 to 12 and Comparative Examples 1 to 4, ultraviolet-curable ink (LUS-170, manufactured by Mimaki Engineering Co., Ltd.) was printed by the inkjet method using an ink-jet printer (UCJV300, manufactured by Mimaki Engineering Co., Ltd.) with an ink volume of 20% and ink color Y to form a printed portion. After printing was completed, the entire printed surface was visually observed and evaluated according to the following criteria. A: Sufficient print density was observed. B: The print density is slightly light, but there is no major problem with the print quality. C: Print density is low.

[0094] (4)Dynamic friction force The dynamic frictional force of the ink-receiving layer of each of the inkjet printing sheets of Examples 1 to 12 against the stainless steel plate was measured in accordance with JIS K7125:1999, with a surface load of 9.8 N and a test speed of 10 mm / min. The results are shown as "(average minimum dynamic frictional force) - (average maximum dynamic frictional force)." A smaller maximum dynamic frictional force indicates improved slipperiness of the ink-receiving layer.

[0095] The evaluation results are shown in Table 1.

[0096] [Table 1]

[0097] The results shown in Table 1 reveal the following: The results shown in Examples 1 to 12 show that when the water contact angle of the ink-receiving layer formed from the ink-receiving layer-forming composition containing the specific energy ray-curable compound (A) and the silicone-based leveling agent (B) is 80° or less, it is possible to suppress print unevenness while ensuring sufficient print density. In contrast, as shown in Comparative Examples 1 and 2, an ink-receiving layer formed from a composition for forming an ink-receiving layer that does not contain a silicone-based leveling agent (B) can ensure sufficient print density, but it is clear that it is unable to suppress print unevenness. Furthermore, as shown in Comparative Examples 3 and 4, when the water contact angle of the ink-receiving layer formed from the ink-receiving layer-forming composition containing the energy ray-curable compound (A) and the silicone-based leveling agent (B) is 81° or more, it is possible to suppress print unevenness, but it is not possible to ensure sufficient print density. Furthermore, a comparison of Example 1 and Example 8 with Example 7 reveals that the incorporation of the filler (C) improves the slipperiness of the ink-receiving layer. [Explanation of symbols]

[0098] 1, 1x, 1y Inkjet Printing Sheet 2, 2x, 2y ink receiving layer 3, 3x, 3y base material 4, 4x, 4y adhesive layer 5, 5x, 5y release liner 5a, 5ax, 5ay Silicone release agent layer 5b, 5bx, 5by support

Claims

1. a laminated structure including an ink-receiving layer, a substrate, a pressure-sensitive adhesive layer, and a release liner in this order; the release liner has a silicone-based release agent layer on the surface that comes into contact with the pressure-sensitive adhesive layer, the ink-receiving layer is a cured layer of an ink-receiving-layer-forming composition containing an energy ray-curable compound (A) and a silicone-based leveling agent (B); the energy ray-curable compound (A) is an ester of a polyol compound and (meth)acrylic acid, The ink-jet printing sheet, wherein the ink-receiving layer has a water contact angle of 80° or less.

2. 2. The sheet for inkjet printing according to claim 1, wherein the energy ray-curable compound (A) further satisfies one or more of the following requirements (X1) to (X3): Requirement (X1): The ester is a partial ester. Requirement (X2): The polyol compound constituting the ester is an alkylene oxide modified product, provided that the alkylene group constituting the alkylene oxide modified product has 2 to 4 carbon atoms. Requirement (X3): The polyol compound constituting the ester has a glycerin skeleton.

3. The sheet for inkjet printing according to claim 1 or 2, wherein the composition for forming the ink-receiving layer further contains a filler (C).

4. 3. The sheet for ink-jet printing according to claim 1, which is in the form of a roll or a wound body wound around a core material.

5. A method of using the inkjet printing sheet according to claim 1 or 2 to form a printed portion on the ink-receiving layer of the inkjet printing sheet using inkjet printing ink.

6. A method for producing a printed matter, comprising the step of forming a printed portion on the ink-receiving layer of the ink-jet printing sheet according to claim 1 or 2 using an ink-jet printing ink.

7. A printed matter having a printed portion printed with ink for ink-jet printing on the ink-receiving layer of the ink-jet printing sheet according to claim 1 or 2.

Images