JP2020001354A - Thermal transfer image receiving sheet - Google Patents

Abstract

To provide a thermal transfer image receiving sheet having a high adhesive force, a curl prevention property and a squeeze-out prevention property of an adhesive material.SOLUTION: A thermal transfer image receiving sheet includes a reception layer, a paper substrate, an adhesive layer containing an adhesive material and a release substrate. In the thermal transfer image receiving sheet, a holding power after one hour measured in accordance with JIS Z 0237 is 100-500 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer image receiving sheet.

  Conventionally, various printing methods are known. Among them, the sublimation type thermal transfer method is capable of freely adjusting the density gradation, has excellent reproducibility of intermediate colors and gradations, and has a high quality comparable to silver halide photography. Image formation is possible.

  In this sublimation type thermal transfer system, a thermal transfer sheet having a dye layer containing a sublimable dye and a thermal transfer image receiving sheet having a receiving layer are superimposed, and then the thermal transfer sheet is heated by a thermal head provided in a thermal transfer printer. The transfer of the sublimable dye in the dye layer to the receiving layer of the thermal transfer image-receiving sheet is performed to form an image and obtain a print.

  Incidentally, in recent years, a seal-type thermal transfer image receiving sheet has been widely known. A seal type thermal transfer image receiving sheet usually includes a receiving layer, a substrate, an adhesive layer, and a release substrate (see Patent Document 1 and the like). The pressure-sensitive adhesive layer of such a thermal transfer image-receiving sheet is usually required to have a high pressure-sensitive adhesive strength.

  As in the case of the recording sheet described in Patent Literature 1, a paper base may be used as a base from the viewpoint of cost and the like. However, a thermal transfer image receiving sheet including a paper base as a base is curled. Since it is easy and the quality of printed matter is impaired, improvement has been demanded.

  Further, heating during image formation on the receiving layer provided on the thermal transfer image-receiving sheet may soften the adhesive layer, extrude the adhesive, and cause contamination in the printer and consequent poor transfer of the thermal transfer image-receiving sheet. There was a need for improvement.

JP-A-8-002092

  The present invention has been made in view of the above problems, and a problem to be solved is to provide a thermal transfer image-receiving sheet, in which the pressure-sensitive adhesive layer has a high pressure-sensitive adhesive property, and further has an anti-curl property and an anti-adhesion property. It is to be.

The thermal transfer image-receiving sheet of the present invention comprises a receiving layer, a paper substrate, an adhesive layer containing an adhesive, and a release substrate,
It is characterized in that the retention force after one hour measured according to JIS Z 0237 is 100 μm or more and 500 μm or less.

  In one embodiment, the adhesive includes a (meth) acrylic resin.

  In one embodiment, the thickness of the adhesive layer is 2 μm or more and 15 μm or less.

  In one embodiment, the thickness of the paper substrate is 80 μm or more and 180 μm or less.

  In one embodiment, the thickness of the release substrate is not less than 20 μm and not more than 200 μm.

  In one embodiment, the thickness of the receiving layer is 2 μm or more and 15 μm or less.

  In one embodiment, the thermal transfer image-receiving sheet includes a porous layer having a thickness of 20 µm or more and 80 µm or less between the substrate and the receiving layer.

  In one embodiment, the thermal transfer image receiving sheet includes a release layer having a thickness of 0.1 μm or more and 2 μm or less between the adhesive layer and the release substrate.

  According to the present invention, it is possible to provide a thermal transfer image-receiving sheet having a high adhesive strength, a curling prevention property and a property of preventing an adhesive material from protruding.

FIG. 2 is a schematic sectional view of a thermal transfer image receiving sheet according to one embodiment. FIG. 2 is a schematic sectional view of a thermal transfer image receiving sheet according to one embodiment. FIG. 2 is a schematic sectional view of a thermal transfer image receiving sheet according to one embodiment. FIG. 2 is a schematic sectional view of a thermal transfer image receiving sheet according to one embodiment. FIG. 2 is a schematic sectional view of a thermal transfer image receiving sheet according to one embodiment. It is the schematic for demonstrating the measuring method of a holding force after 1 hour.

(Heat transfer image receiving sheet)
As shown in FIG. 1, the thermal transfer image receiving sheet 10 of the present invention includes a receiving layer 11, a paper base 12, an adhesive layer 13, and a release base 14.
Further, in one embodiment, the thermal transfer image-receiving sheet 10 of the present invention includes a porous layer 15 between a receiving layer 11 and a paper substrate 12, as shown in FIG.
In one embodiment, the thermal transfer image-receiving sheet 10 of the present invention includes a release layer 16 between the adhesive layer 13 and the release substrate 14, as shown in FIG.
In one embodiment, the thermal transfer image-receiving sheet 10 of the present invention includes a back surface layer 17 on the surface of the release substrate 13 opposite to the surface on which the adhesive layer 12 and the like are provided, as shown in FIG.
In one embodiment, the thermal transfer image-receiving sheet 10 of the present invention includes an adhesive layer 18 between the paper base 12 and the porous layer 15 as shown in FIG.
Further, in one embodiment, the thermal transfer image-receiving sheet 10 of the present invention includes a primer layer 19 between any layers. For example, as shown in FIG. 5, it is provided between the receiving layer 11 and the porous layer 15 and between the release substrate 14 and the back surface layer 17.

The thermal transfer image-receiving sheet of the present invention is characterized in that the retention force after 1 hour measured according to JIS Z 0237 (issued in 2009) is 100 μm or more and 500 μm or less. Recently, the present inventors have found that by setting the holding force after one hour of the thermal transfer image-receiving sheet within a specific numerical range, the adhesive force, the curl-preventing property, and the adhesive-material-preventing property of the thermal transfer image-receiving sheet can be remarkably improved. Was found.
More preferably, the holding force is 200 or more and 300 or less.
Although the adjustment of the holding force is not particularly limited, for example, it can be performed by adjusting the types of the pressure-sensitive adhesive and the hardening material, and the amounts used thereof.

The method for measuring the retention force after one hour in the present invention will be described below.
First, a test piece having a width of 20 mm is prepared from the thermal transfer image receiving sheet. Next, as shown in FIG. 6, the release substrate is peeled off from the test piece 20, and the adhesive layer 12 is attached to a PET film 21 that has not been subjected to a surface treatment with an adhesive area of 20 mm in width and 20 mm in length. A 1 kg pressure roll is reciprocated 5 times at a speed of 40 m / min to perform pressure bonding, and is allowed to stand at 25 ° C. for 30 minutes.
After the standing, as shown in FIG. 6, a 1 kg weight 22 was attached to one end of the test piece 20, and the test piece 20 was allowed to stand still in an environment of 80 ° C. for 1 hour. Time retention.

  Hereinafter, each layer included in the thermal transfer image-receiving sheet of the present invention will be described.

(Receiving layer)
The receiving layer is a layer that receives the sublimable dye migrating from the dye layer of the thermal transfer sheet and maintains the formed image.

  The receiving layer contains at least one resin material, and examples thereof include polyolefin, vinyl resin, (meth) acrylic resin, cellulose resin, polyester, polyamide, polycarbonate, styrene resin, polyurethane, and ionomer resin.

  The content of the resin material in the receiving layer is not particularly limited, and may be, for example, not less than 80% by mass and not more than 98% by mass.

In one embodiment, the receiving layer includes one or more release agents. Thereby, the releasability from the thermal transfer sheet after image formation can be improved.
Examples of the release material include solid waxes such as polyethylene wax and amide wax, fluorine-based surfactants, phosphate-based surfactants, silicone oil, reactive silicone oil, curable silicone oil, and silicone resin. Can be

  The content of the release material in the receiving layer is preferably 0.5% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less. Thereby, the releasability from the thermal transfer sheet after image formation can be further improved.

  The receiving layer may be a release material, a plasticizer, a filler, an ultraviolet light stabilizer, a coloring prevention material, a surfactant, a fluorescent whitening material, a matting material, a deodorant material as long as the properties of the present invention are not impaired. It may contain additives such as flame retardant materials, weather resistant materials, antistatic materials, yarn friction reducing materials, slip materials, antioxidants, ion exchange materials, dispersants, ultraviolet absorbers and coloring materials such as pigments and dyes. it can.

  The thickness of the receiving layer is preferably 2 μm or more and 15 μm or less, more preferably 5 μm or more and 10 μm or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved, and the image density formed on the receiving layer can be improved.

  The receiving layer is obtained by dispersing or dissolving the above-mentioned material in water or a suitable solvent to form a coating solution, which is then subjected to a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod. It can be formed by applying a known method such as a coating method on a paper substrate or the like to form a coating film, and drying the coating film.

(Paper base)
Paper bases include, for example, art paper, coated paper, mat coated paper, resin coated paper, cast coated paper, coated paper such as kraft paper and baryta paper, high quality paper, medium paper, paperboard, impregnated paper, and vapor deposition Paper, acidic paper, neutral paper and the like can be used.
Among these, coated paper is preferred, and coated paper is more preferred, for reasons of both dimensional stability and formation.
In the present invention, the term “coated paper” refers to information paper, such as medium paper, on which at least one surface is coated with a paint of 10 μm or more and 30 μm or less.

  The thickness of the paper substrate is preferably 80 μm or more and 180 μm or less, and more preferably 100 μm or more and 150 μm or less. Thereby, the curl prevention can be further improved.

(Adhesive layer)
The adhesive layer contains at least one kind of adhesive, for example, an adhesive containing (meth) acrylic resin, an adhesive containing epoxy resin, an adhesive containing polyamide, an adhesive containing styrene resin, and a rubber material. Materials, an adhesive containing silicone resin, an adhesive containing polyurethane, and the like. Among these, an adhesive containing a (meth) acrylic resin is preferable from the viewpoints of the adhesive strength of the thermal transfer image-receiving sheet, the curl preventing property, and the sticking-out preventing property of the adhesive.
In the present invention, “(meth) acryl” means to include both “acryl” and “methacryl”.

  The content of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer is preferably 50% by mass or more, and more preferably 70% by mass or more. Thereby, the adhesive force, the curl prevention property, and the sticking-out property prevention property of the thermal transfer image-receiving sheet can be further improved.

Further, in one embodiment, the adhesive layer includes at least one type of curing agent. Thereby, the adhesive force, the curl prevention property, and the sticking-out property prevention property of the thermal transfer image-receiving sheet can be further improved.
Examples of the curing agent include an epoxy curing agent, an isocyanate curing agent, a melamine curing agent, an oxazoline curing agent, an aziridine curing agent, a metal chelate curing agent, and an amine curing agent. Among these, an epoxy curing material and an isocyanate curing material are preferable from the viewpoints of the adhesive strength of the thermal transfer image-receiving sheet, the curl prevention property, and the prevention of the sticking material from protruding.

When an adhesive having a viscosity of less than 8 Pa / s is used, the amount of the curing agent to be used is preferably 2 parts by mass or more, more preferably 5 parts by mass or more based on 100 parts by mass of the adhesive. . Thereby, the sticking-out preventing property of the adhesive can be further improved.
When an adhesive having a viscosity of 8 Pa / s or more is used, the amount of the curing agent used is preferably 0.5 parts by mass or more, and more preferably 2 parts by mass or more with respect to 100 parts by mass of the adhesive. Is more preferable. Thereby, the sticking-out preventing property of the adhesive can be further improved. The amount of the curing agent used is preferably 7 parts by mass or less, more preferably 4 parts by mass or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved.
The viscosity is measured at 25 ° C. by using an E-type viscometer.

  Examples of the epoxy curing agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol. Diglycidyl ether, tetraglycidyl xylene diamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc. Is mentioned.

  As the isocyanate curing agent, tolylene diisocyanate, xylylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogen Additive xylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, trimethylolpropane-tolylene diisocyanate adduct, trimethylolpropane-hexamethylene diisocyanate adduct, and the like.

  The pressure-sensitive adhesive layer may contain the above-mentioned additive as long as the properties of the present invention are not impaired.

  The thickness of the adhesive layer is preferably 2 μm or more and 15 μm or less. Thereby, the adhesive force, the curl prevention property, and the sticking-out property prevention property of the thermal transfer image-receiving sheet can be further improved.

  The pressure-sensitive adhesive layer is obtained by dispersing or dissolving the above material in water or a suitable solvent to form a coating liquid, which is then subjected to a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and the like. It can be formed by applying a known method such as a rod coating method on a paper substrate to form a coating film, and then drying the coating film.

(Release substrate)
Examples of the release substrate include paper substrates such as high-quality paper, art paper, coated paper, resin-coated paper, cast-coated paper, paperboard, synthetic paper, and impregnated paper, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), Polyesters such as polyethylene naphthalate (PEN), 1,4-polycyclohexylene dimethylene terephthalate and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, polyamides such as nylon 6 and nylon 6,6, polypropylene (PP), Polyolefins such as polyethylene (PE) and polymethylpentene; polyvinyl chloride; polyvinyl alcohol (PVA); polyvinyl acetate; vinyl chloride-vinyl acetate copolymer; polyvinyl resins such as polyvinyl butyral and polyvinyl pyrrolidone (PVP); (Meth) acrylic resins such as acrylate, polymethacrylate and polymethylmethacrylate, imide resins such as polyimide and polyetherimide, cellophane, cellulose acetate, nitrocellulose, cellulose acetate propionate (CAP) and cellulose acetate butyrate A film containing a resin material such as a cellulose resin such as (CAB), a styrene resin such as polystyrene (PS), a polycarbonate, and an ionomer resin (hereinafter, simply referred to as a resin film) can be used. In the present invention, “(meth) acrylate” means both “aclate” and “methacrylate”.

  The surface of the release substrate is preferably subjected to a surface treatment such as a corona treatment, a flame treatment, a plasma treatment, and a flame treatment in order to improve the adhesion to an adjacent layer.

  The thickness of the release substrate is preferably 20 μm or more and 200 μm or less, and more preferably 50 μm or more and 125 μm or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved. Further, the release substrate can be more easily peeled off from the adhesive layer, and it is possible to prevent wrinkles (hereinafter, referred to as peeling wrinkles) from being generated in the adhesive layer during peeling.

  The release substrate can be produced by forming the above-mentioned material into a film by a conventionally known method, and when forming the adhesive layer, the film can be laminated on the paper substrate via the adhesive layer. Note that a commercially available film may be used as the release substrate.

(Porous layer)
In one embodiment, the thermal transfer image-receiving sheet of the present invention includes a porous layer between a paper substrate and a receiving layer. As a result, heat loss during image formation can be reduced, and cushioning properties can be imparted to the thermal transfer image receiving sheet, so that a better image can be formed on the receiving layer.

In one embodiment, the porous layer is a porous resin film having fine voids inside.
The porous resin film contains at least one resin material, and examples thereof include polyester, polyamide, polyolefin, vinyl resin, (meth) acrylic resin, imide resin, cellulose resin, styrene resin, polycarbonate, and ionomer resin.
Among these, polyester and polyolefin are preferable, PET and PP are more preferable, and PET is particularly preferable from the viewpoint of preventing occurrence of peeling wrinkles.

  The porous resin film can contain the above-mentioned additives within a range not to impair the properties of the present invention.

  Further, the surface of the porous resin film is preferably subjected to the above-mentioned surface treatment in order to improve the adhesion to an adjacent layer.

In another embodiment, the porous layer includes hollow particles and a resin material.
The hollow particles may be organic hollow particles composed of a resin material or the like, or may be inorganic hollow particles composed of a glass or the like.However, the organic hollow particles are excellent in dispersibility. Is preferred.
Examples of the resin material constituting the organic hollow particles include a styrene resin, a (meth) acrylic resin, a phenol resin, a fluororesin, a polyamide, an imide resin, a polycarbonate, and a polyether.
Further, the hollow particles may be expanded particles or non-expanded particles.
The volume average particle size of the hollow particles is not particularly limited, but may be, for example, 0.1 μm or more and 15 μm or less.
The volume average particle size is measured using a particle size distribution / particle size distribution measuring device (Nanotrack particle size distribution measuring device, manufactured by Nikkiso Co., Ltd.) in accordance with JIS Z 8819-2 (issued in 2001). .

  Examples of the resin material include polyester, polyamide, polyolefin, vinyl resin, (meth) acrylic resin, imide resin, cellulose resin, styrene resin, polycarbonate, and ionomer resin.

  The thickness of the porous layer is preferably 20 μm or more and 80 μm or less, and more preferably 35 μm or more and 75 μm or less. Thereby, the curl prevention of the thermal transfer image-receiving sheet can be further improved, and a higher density image can be formed on the receiving layer.

When the porous layer is made of a porous resin film, the porous resin film can be produced by a known method. For example, a mixture obtained by kneading insoluble organic particles or inorganic particles with the resin material described above. Into a film. In one embodiment, the porous resin film can be produced by forming a film containing a mixture containing a first resin material and a second resin material having a higher melting point than the first resin material. In this case, the second resin material functions as a nucleus material for forming a fine void.
In the present invention, a commercially available porous film may be used.
When the porous layer is a porous resin film, it can be formed by bonding the film to a paper base via the following adhesive layer.
When the porous layer is a layer containing hollow particles and a resin material, the porous layer is obtained by dispersing or dissolving the above-mentioned material in water or a suitable solvent to form a coating liquid, which is then roll-coated. It is formed by applying a known method such as a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method on a paper substrate to form a coating film, and then drying the coating film. it can.

(Release layer)
In one embodiment, the thermal transfer image-receiving sheet of the present invention may include a release layer between the adhesive layer and the release substrate. The release layer is a layer that is peeled off from the adhesive layer together with the release substrate when the release substrate is peeled off.By providing the release layer, the adhesion between the release substrate and the adhesive layer can be adjusted, and the release wrinkles can be removed. Occurrence can be prevented.

  In one embodiment, the release layer includes one or more resin materials, such as (meth) acrylic resin, polyurethane, acetal resin, polyamide, polyester, melamine resin, polyol resin, cellulose resin, and silicone. Resins. Among these, silicone resins are particularly preferable from the viewpoint of mold release properties.

  In one embodiment, the release layer includes one or more release materials, for example, a silicone oil, a phosphate plastic material, a fluorine compound, a wax, a metal soap, a filler, and the like. .

  The release layer can contain the above-mentioned additive as long as the properties of the present invention are not impaired.

  The thickness of the release layer is preferably from 0.1 μm to 2 μm, more preferably from 0.2 μm to 1 μm. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved.

  The release layer is obtained by dispersing or dissolving the above material in water or a suitable solvent to form a coating liquid, which is then subjected to a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method. A known method such as a rod coating method or the like can be used to form a coating film by applying the composition on a release substrate and drying the coating film.

(Back layer)
In one embodiment, the thermal transfer image-receiving sheet of the present invention includes a back surface layer on the surface of the release substrate opposite to the surface on which the adhesive layer or the like is provided. Thereby, the transportability of the thermal transfer image receiving sheet in the printer can be improved, and curling of the thermal transfer image receiving sheet can be prevented.

  In one embodiment, the back layer includes one or more resin materials, such as polyolefin, vinyl resin, (meth) acrylic resin, cellulose resin, polyester, polyamide, polycarbonate, styrene resin, polyurethane, and the like. Can be

  In one embodiment, the backside layer comprises one or more fillers, for example, organic fillers such as (meth) acrylic particles, polyamide particles and polyethylene wax and silicon dioxide particles, calcium carbonate particles and oxidized particles. Examples include inorganic fillers such as titanium particles. Further, an organic-inorganic hybrid type filler may be used.

  The back surface layer can contain the above-mentioned additive as long as the properties of the present invention are not impaired.

  The thickness of the back surface layer is preferably 0.5 μm or more and 4 μm or less, more preferably 1 μm or more and 3 μm or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved.

  The back layer is prepared by dispersing or dissolving the above material in water or a suitable solvent to form a coating liquid, which is then roll-coated, reverse roll-coated, gravure coated, reverse gravure coated, bar-coated, and rod-coated. It can be formed by applying a known method such as a coating method on a release substrate or the like to form a coating film, and drying the coating film.

(Adhesive layer)
In one embodiment, the thermal transfer image-receiving sheet of the present invention includes an adhesive layer between a paper substrate and a porous layer.

  In one embodiment, the adhesive layer includes one or more resin materials, and examples thereof include polyester, polyurethane, polycarbonate, (meth) acrylic resin, styrene resin, vinyl resin, and cellulose resin.

  In one embodiment, an adhesive layer contains the above-mentioned hardening material.

  The thickness of the adhesive layer is preferably 1 μm or more and 15 μm or less, more preferably 2 μm or more and 10 μm or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved.

  The adhesive layer is obtained by dispersing or dissolving the above material in water or a suitable solvent to form a coating liquid, and applying the coating liquid by a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a known method such as a coating method on a paper substrate to form a coating film, and drying the coating film.

(Primer layer)
In one embodiment, the thermal transfer image-receiving sheet of the present invention includes a primer layer between any layers. Thereby, the adhesion between the layers can be improved.

  In one embodiment, the primer layer contains one or more resin materials, and examples thereof include polyester, polyurethane, polycarbonate, (meth) acrylic resin, styrene resin, vinyl resin, and cellulose resin.

  In one embodiment, the primer layer comprises a layered silicate. Thereby, conductivity can be imparted to the primer layer, and the judgment of the printed matter can be improved.

  In addition, the primer layer may contain the above-mentioned additive as long as the characteristics of the present invention are not impaired.

  The thickness of the primer layer is preferably 0.5 μm or more and 5 μm or less, more preferably 0.7 μm or more and 2 μm or less. Thereby, the curl prevention of the thermal transfer image receiving sheet can be further improved.

  The primer layer is obtained by dispersing or dissolving the above material in water or a suitable solvent to form a coating solution, and applying the coating solution by a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a known method such as a coating method on a substrate or the like to form a coating film, and drying the coating film.

  Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Except where otherwise described below, contents, blending ratios, and the like are based on mass.

Example 1
As the paper base material, coated paper A (S Utrilo (registered trademark) coat, manufactured by Daio Paper Co., Ltd.) having a thickness of 105 μm was prepared.
On one surface of the paper base material, a coating liquid for forming an adhesive layer having the following composition was applied and dried to form an adhesive layer having a thickness of 3 μm, and through the adhesive layer, a porous layer having a thickness of 38 μm was formed. (Crispar (registered trademark) K1211, manufactured by Toyobo Co., Ltd.).
(Coating liquid for forming adhesive layer)
-30 parts by mass of polyurethane (Takelac (registered trademark) A-969V, manufactured by Mitsui Chemicals, Inc.)
-Isocyanate compound 10 parts by mass (Takenate (registered trademark) A-5, manufactured by Mitsui Chemicals, Inc.)
・ Ethyl acetate 60 parts by mass

On the porous layer, a coating liquid for forming a primer layer having the following composition was applied and dried to form a primer layer having a thickness of 1.0 μm.
(Coating liquid for forming primer layer)
Polyester 10 parts by mass (Polyester (registered trademark) WR905, manufactured by Nippon Synthetic Chemical Co., Ltd.)
-Conductive synthetic layered silicate 10 parts by mass (Laponite JS, manufactured by Wilper Ellis Co., Ltd.)
・ 80 parts by mass of water

A coating liquid for forming a receiving layer having the following composition was applied on the primer layer and dried to form a receiving layer having a thickness of 4.0 μm.
(Coating liquid for receiving layer formation)
-Vinyl chloride-vinyl acetate copolymer 12 parts by mass (Solvain (registered trademark) C, manufactured by Nissin Chemical Industry Co., Ltd.)
・ Epoxy-modified silicone 0.8 parts by mass (X-22-3000T, manufactured by Shin-Etsu Chemical Co., Ltd.)
-0.24 parts by mass of amino-modified silicone (X-22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Toluene 30 parts by mass ・ Methyl ethyl ketone (MEK) 30 parts by mass

A PET film (E5000, manufactured by Toyobo Co., Ltd.) having a thickness of 50 μm was prepared as a release substrate, and a coating liquid for forming a release layer having the following composition was applied to one surface of the PET film and dried. A release layer of 5 μm was formed.
(Coating liquid for release layer formation)
・ 100 parts by mass of silicone resin (KS-847H, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ 200 parts by mass of toluene

A coating liquid for forming an adhesive layer having the following composition is applied to the other surface of the paper substrate and dried to form an adhesive layer having a thickness of 10 μm, and the release substrate and the release layer are formed through the adhesive layer. The laminate of the above, laminated from the side on which the release layer is provided, a receiving layer, a primer layer, a porous layer, an adhesive layer, a paper substrate, an adhesive layer, a release layer, A thermal transfer image-receiving sheet comprising a release substrate and a release substrate in this order was obtained.
(Coating liquid for forming adhesive layer)
45 parts by mass of (meth) acrylic adhesive (SK Dyne (registered trademark) 1251, manufactured by Soken Chemical Co., Ltd., viscosity 6.5 Pa / s)
・ Epoxy compound 1 part by mass (E-AX, manufactured by Soken Chemical Co., Ltd.)
・ 0.3 parts by mass of isocyanate compound (L-45, manufactured by Soken Chemical Co., Ltd.)
・ Ethyl acetate 53.7 parts by mass

Examples 2 to 15 and Comparative Examples 1 and 2
The type of porous resin film used for the porous layer, the type and thickness of the paper substrate, the type and content of the adhesive in the adhesive layer, the content of the curing agent, the thickness of the adhesive layer, and the thickness of the release substrate A thermal transfer image-receiving sheet was produced in the same manner as in Example 1, except that at least one of the kind and the thickness was changed as shown in Table 1.
The details of each constituent material in Table 1 are as follows.
(Porous layer)
・ Crisper (registered trademark) K1212: manufactured by Toyobo Co., Ltd., thickness 75 μm
(Paper base)
-Coated paper B: S Utrilo (registered trademark) coated, manufactured by Daio Paper Co., Ltd., 156 μm in thickness
-Fine paper: manufactured by Nippon Paper Industries, Shiraoi (registered trademark), 96 μm thick
(Adhesive layer)
-SK Dyne (registered trademark) 1310: manufactured by Soken Chemical Co., Ltd., (meth) acrylic adhesive, viscosity 9 Pa / s
-SK Dyne (registered trademark) 1717: manufactured by Soken Chemical Co., Ltd., (meth) acrylic adhesive, viscosity 6.5 Pa / s
(Release substrate)
・ E5007: Toyobo Co., Ltd., thickness 25 μm

<< Measurement of retention force after 1 hour >>
A test piece having a width of 20 mm was prepared from each of the thermal transfer image-receiving sheets obtained in the above Examples and Comparative Examples. Next, the release substrate was peeled off from the test piece, and the pressure-sensitive adhesive layer was adhered to a PET film that had not been subjected to surface treatment with an adhesion area of 20 mm in width × 20 mm in length, and a 1 kg compression roll was applied at 40 mm / min. 5 times reciprocation at the speed described above and pressure bonding, and allowed to stand in an environment of 25 ° C. for 30 minutes.
After standing, a 1 kg weight is attached to one end of the test piece according to JIS Z 0237, and the test piece is allowed to stand at 80 ° C. for 1 hour, and then the moving distance of the test piece (holding force after 1 hour) is measured. did. Table 1 summarizes the measurement results.

<<<< Adhesive strength evaluation test >>
A test piece having a width of 25 mm and a length of 100 mm was prepared from each of the thermal transfer image receiving sheets obtained in the above Examples and Comparative Examples. Next, the release substrate was peeled off from the test piece, the adhesive layer was attached to a stainless steel plate with an adhesive area of 25 mm in width and 75 mm in length, and a 1 kg pressure roll was reciprocated 5 times at a speed of 40 m / min, and pressed. It was left still for 1 minute in an environment of 25 ° C.
After standing, the peeling force when the test piece is peeled off from the stainless steel plate in the length direction at a tensile speed of 300 mm / min by the 180 ° peeling method according to JIS Z 0237 (issued in 2009). Was measured using a Tensilon tensile tester (Autograph, manufactured by Shimadzu Corporation), and the adhesive strength of the thermal transfer image-receiving sheet was evaluated based on the following evaluation criteria. In the measurement of the peeling force, the peeling force data for the 25 mm portion where peeling started was rejected, and the average of the peeling force after that was adopted.
(Evaluation criteria)
A: The peeling force was 10 N / 25 mm or more.
B: The peel force was 2 N / 25 mm or more and less than 10 N / 25 mm.
NG: The peeling force was less than 2 N / 25 mm.

<< Curl prevention evaluation test >>
A test piece having a width of 152.4 mm and a length of 101.6 mm was prepared from each of the thermal transfer image receiving sheets obtained in the above Examples and Comparative Examples.
After the test piece was allowed to stand for 24 hours in an environment of 20 ° C. and a relative humidity of 60%, the test piece was placed on a flat table so that the four corners were lifted, and the lift height of the four corners was measured. Specifically, in the case of a curl in which the receiving layer surface side is concave, it is placed on a flat table so that the receiving layer surface is upward, and in the case of a curl in which the receiving layer surface side is convex, the receiving layer surface is downward. The measurement was performed on a flat table. The maximum lift height at the four corners is defined as the amount of curl (a positive value for the convex curl toward the receiving layer, and a negative value for the concave curl toward the receiving layer), and the curl of the thermal transfer image-receiving sheet based on the following evaluation criteria. The prevention was evaluated. The evaluation results are summarized in Table 1. Table 1 also shows the measured curl amounts.
(Evaluation criteria)
A: The absolute value of the curl amount was less than 3 mm.
B: The absolute value of the curl amount was 3 mm or more and less than 10 mm.
NG: The absolute value of the curl amount was 10 mm or more.

<< Test to prevent sticking material from protruding >>
Each of the thermal transfer image-receiving sheets obtained in the above Examples and Comparative Examples was formed into a roll having a width of 152.4 mm, and a sublimation type thermal transfer printer (DS-RX1, manufactured by Dai Nippon Printing Co., Ltd.) was used. (Manufactured by Dai Nippon Printing Co., Ltd.).
Image formation under the environment of 40 ° C. and relative humidity of 80% and cutting in the width direction of the thermal transfer image receiving sheet are repeated on a receiving layer provided on the thermal transfer image receiving sheet to have a size of width 152.4 mm × length 101.6 mm. 100 prints were produced. The inside of the printer after the production of the printed matter was visually observed, and the heat transfer image-receiving sheet was evaluated for its sticking-out prevention property based on the following evaluation criteria.
(Evaluation criteria)
A: No adhesion of the adhesive material was confirmed on the transfer path of the thermal transfer image receiving sheet in the printer.
B: Adhesion of a small amount of adhesive was confirmed on the thermal transfer image-receiving sheet conveyance path in the printer, but it was not practically problematic.
NG: A large amount of adhesion of the adhesive material was confirmed in the transfer path of the thermal transfer image-receiving sheet in the printer, and there was a problem in practical use.

10: thermal transfer image-receiving sheet, 11: receiving layer, 12: paper substrate, 13: adhesive layer, 14: release substrate, 15: porous layer, 16: release layer, 17: back layer, 18: adhesive layer 19 : Primer layer, 20: test piece, 21: PET film

Claims (8)

A receiving layer, a paper substrate, an adhesive layer containing an adhesive, and a release substrate,
A thermal transfer image-receiving sheet, characterized in that the retention force after one hour measured according to JIS Z 0237 is 100 μm or more and 500 μm or less.   The thermal transfer image-receiving sheet according to claim 1, wherein the adhesive contains a (meth) acrylic resin.   The thermal transfer image-receiving sheet according to claim 1, wherein the thickness of the adhesive layer is 2 μm or more and 15 μm or less.   The thermal transfer image-receiving sheet according to any one of claims 1 to 3, wherein the thickness of the paper substrate is from 80 m to 180 m.   The thermal transfer image-receiving sheet according to any one of claims 1 to 4, wherein the thickness of the release substrate is 20 µm or more and 200 µm or less.   The thermal transfer image-receiving sheet according to claim 1, wherein the thickness of the receiving layer is 2 μm or more and 15 μm or less.   The thermal transfer image-receiving sheet according to claim 6, further comprising a porous layer having a thickness of not less than 20 m and not more than 80 m between the paper base and the receiving layer.   The thermal transfer image-receiving sheet according to claim 1, further comprising a release layer having a thickness of 0.1 μm or more and 2 μm or less between the adhesive layer and the release substrate.

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