JP2016210155A - Thermal transfer image receiving sheet and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer image receiving sheet with a handling property improved, and to provide a manufacturing method thereof.SOLUTION: A thermal transfer image receiving sheet includes a substrate, a reception layer on one face of the substrate, and a rear face resin layer on the other face of the substrate. The surface roughness Ra of the rear face resin layer is 0.65-1.14 μm. A handling property can be improved by using the thermal transfer image receiving sheet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer image-receiving sheet and a method for producing the same, and more specifically, a base material, a receiving layer on one surface of the base material, and a back resin layer on the other surface of the base material. The present invention relates to a thermal transfer image receiving sheet and a method for producing the same.

  Conventionally, various printing methods are known. Among them, the thermal diffusion type transfer method (sublimation type thermal transfer method) uses a sublimation dye as a color material, so that density gradation can be freely adjusted, and intermediate colors and gradations can be adjusted. It has excellent tone reproducibility and can form high-quality images comparable to silver halide photographs.

  This thermal diffusion transfer system is a method in which a thermal transfer ink sheet containing a dye (sublimation dye) and a thermal transfer image receiving sheet are superposed, and then the ink sheet is heated by a thermal head whose heat generation is controlled by an electrical signal. The dye in the ink sheet is transferred to the image receiving sheet to record image information. As such thermal diffusion transfer systems become widespread, the printing speed has been increased, and sufficient color density can be obtained even if the conventional thermal energy is printed using the conventional thermal transfer ink sheet and thermal transfer image receiving sheet. There are problems such as inability to obtain.

  Furthermore, there are various other problems in the thermal diffusion transfer system. For example, due to insufficient releasability of the image receiving sheet, the ink sheet sticks to the receiving layer surface of the image receiving sheet at the time of printing, and when the ink sheet is peeled off from the image receiving layer after printing, generation of peeling sound, Problems such as poor running and occurrence of peeling lines on the image have occurred.

  In sublimation transfer printing materials, for example, when 100 or more prints are continuously printed, the thermal transfer image-receiving sheet is peeled off from the front and back, peeled off from the ink ribbon, and friction between the printer and the conveying member in the printer system. There has been a problem that the handleability (hereinafter referred to as “separation”) of a printed matter printed by the static electricity is deteriorated. Therefore, it has been proposed to add a conductive agent to the release layer of the sublimation thermal transfer recording medium (ink ribbon) in order to improve the dispersibility (see Patent Document 1). Further, in order to improve the dispersibility, it has been proposed that a layered silicate is contained in at least one of the layers constituting the surface side having the receiving layer on the substrate in the thermal transfer image-receiving sheet (see Patent Document 2). ). However, even if it is any method of patent document 1 and 2, it is necessary to add an additive and an increase in cost is inevitable. In addition, when manufacturing an ink ribbon or a thermal transfer image-receiving sheet having a different layer structure, it is necessary to verify the mixing ratio of each layer again, and it is unclear whether or not the desired effect is exhibited. It wasn't.

JP 2011-194707 A JP 2013-082219 A

  The present invention has been made in view of the above-described background art, and an object thereof is to provide a thermal transfer image-receiving sheet with improved separation characteristics and a method for producing the same.

  As a result of intensive studies to solve the above problems, the present inventors have determined that the surface roughness Ra of the back surface resin layer formed on the surface opposite to the receiving layer of the substrate is within a specific range in the thermal transfer image receiving sheet. It has been found that the above problems can be solved by controlling. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
A thermal transfer image receiving sheet comprising a substrate, a receiving layer on one surface of the substrate, and a back resin layer on the other surface of the substrate,
A thermal transfer image receiving sheet is provided in which the surface roughness Ra of the back surface resin layer is 0.65 μm or more and 1.14 μm or less.

  In the aspect of the present invention, it is preferable that a hollow layer is further provided between the base material and the receiving layer.

  In the aspect of the present invention, it is preferable that a primer layer is further provided between the hollow layer and the receiving layer.

  In the aspect of the present invention, it is preferable that a surface resin layer is further provided between the base material and the hollow layer.

  In the aspect of this invention, it is preferable that the said back surface resin layer contains polyolefin resin.

According to another aspect of the present invention,
A method for producing a thermal transfer image receiving sheet, comprising a base material, a receiving layer on one surface of the base material, and a back surface layer on the other surface of the base material,
While extruding the resin onto the base material, the resin is passed between the pair of satin rolls and nip rolls so that the resin is in contact with the satin rolls, and the surface roughness Ra is 0.65 μm or more and 1.14 μm or less. There is provided a method for producing a thermal transfer image receiving sheet, comprising a step of forming a back surface resin layer on the substrate.

According to another aspect of the present invention,
A method for producing a thermal transfer image receiving sheet, comprising a base material, a receiving layer on one surface of the base material, and a back surface resin layer on the other surface of the base material,
A method for producing a thermal transfer image receiving sheet, comprising a step of embossing a back surface resin layer of the thermal transfer image receiving sheet using a satin roll and adjusting a surface roughness Ra of the back surface resin layer to 0.65 μm or more and 1.14 μm or less. .

  In another aspect of the present invention, it is preferable that the surface roughness Ra of the satin roll is 0.66 μm or more and 5.86 μm or less.

  In another aspect of the present invention, the satin roll preferably has a temperature of 100 to 130 ° C.

  According to the present invention, by adjusting the surface roughness Ra of the back surface resin layer within a specific numerical range without adding a separate additive to the thermal transfer image-receiving sheet, the friction resistance is reduced and the spreading property is improved. Can be made. Further, since charging due to friction is suppressed only by the uneven shape of the back surface resin layer, a desired effect can be exhibited regardless of the layer configuration of the thermal transfer image receiving sheet.

1 is a schematic cross-sectional view showing an embodiment of a thermal transfer image receiving sheet according to the present invention. It is the schematic diagram which showed one Embodiment of the manufacturing method of the thermal transfer image receiving sheet by this invention.

<Thermal transfer image receiving sheet>
The thermal transfer image-receiving sheet according to the present invention comprises a substrate, a receiving layer on one surface of the substrate, and a back resin layer on the other surface of the substrate. The thermal transfer image-receiving sheet may further include a hollow layer between the base material and the receiving layer, may further include a primer layer between the hollow layer and the receiving layer, and a surface resin between the base material and the hollow layer. A layer may further be provided.

  The layer configuration of one embodiment of the thermal transfer image receiving sheet according to the present invention will be described with reference to the schematic cross-sectional view of FIG. A thermal transfer image receiving sheet 10 shown in FIG. 1 includes a base material 11, a surface resin layer 16, a hollow layer 15, a primer layer 14, and a receiving layer 13 in this order on one surface of the base material 11. The back surface layer 12 is provided on the other surface (surface opposite to the receiving layer 13) of the base material. Hereinafter, each layer constituting the thermal transfer image receiving sheet of the present invention will be described.

(Base material layer)
Since the base layer of the thermal transfer image-receiving sheet is heated during thermal transfer, it is preferable to use a material having a mechanical strength that does not hinder handling even when heated. As a material for such a base material layer, it is preferable to use a paper base material. Examples of paper base materials include condenser paper, glassine paper, sulfuric acid paper, synthetic paper (polyolefin, polystyrene), fine paper, art paper, coated paper, resin coated paper, cast coated paper, paperboard, base paper, and photographic base paper , Synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, and synthetic resin internal paper.

  Although the thickness of a base material layer is not specifically limited, Preferably it is 50 micrometers or more and 300 micrometers or less, More preferably, they are 100 micrometers or more and 250 micrometers or less, More preferably, they are 120 micrometers or more and 180 micrometers or less. When the thickness of the base material layer is within the above range, the rigidity of the obtained thermal transfer image-receiving sheet is suitable.

(Resin layer)
When using a paper base material as the base material layer, it is preferable to provide resin layers on both the receiving layer side (front surface side) and the back surface side of the core material made of the paper base material. As the resin layer, it is preferable to provide a polyolefin resin layer, for example, high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene, polybutene, polyisobutene, polyisobutylene, polybutadiene, polyisoprene, ethylene-vinyl acetate copolymer, etc. Among them, polypropylene, high density polyethylene, medium density polyethylene, and low density polyethylene are preferably used. In order to improve whiteness, a filler such as titanium oxide may be added to the surface resin layer on the receiving layer side.

  The back surface resin layer has a surface roughness Ra of 0.65 to 1.14 μm, preferably 0.7 to 1.1 μm, and more preferably 0.75 to 1.05 μm. By adjusting the surface roughness Ra of the back surface resin layer within the above range, the contact area can be reduced, the charge amount can be suppressed, and the dispersibility can be improved. Although the adjustment method of surface roughness Ra of a back surface resin layer is not specifically limited, For example, it can adjust suitably using a satin finish roll which is demonstrated with the following manufacturing method.

  In the present invention, the surface roughness Ra is an arithmetic average roughness, and is a value measured in accordance with JIS B 0601. For example, it can be measured with a surface roughness measuring machine (trade name: Surfcom, manufactured by Tokyo Seimitsu Co., Ltd.).

(Receptive layer)
The receiving layer of the thermal transfer image receiving sheet is for receiving the sublimation dye transferred from the thermal transfer ink sheet and maintaining the formed image. As the resin for forming the receiving layer, polycarbonate resin, polyester resin, polyamide resin, acrylic resin, cellulose resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid Examples include vinyl copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyurethane resins, polystyrene resins, polypropylene resins, polyethylene resins, ethylene-vinyl acetate copolymer resins, and epoxy resins.

  The thermal transfer image receiving sheet can have a release agent in the receiving layer in order to improve the release property from the thermal transfer ink sheet. Various release agents such as solid waxes such as polyethylene wax, amide wax, Teflon (registered trademark), fluorine-based or phosphate-based surfactant, silicone oil, reactive silicone oil, curable silicone oil, etc. Silicone oil and various silicone resins can be mentioned, and silicone oil is preferable. An oily oil can be used as the silicone oil, but a modified silicone oil is preferred. As the modified silicone oil, amino-modified silicone, epoxy-modified silicone, aralkyl-modified silicone, epoxy-aralkyl-modified silicone, alcohol-modified silicone, vinyl-modified silicone, urethane-modified silicone and the like can be preferably used, but epoxy-modified silicone, aralkyl-modified silicone, etc. Epoxy-aralkyl-modified silicones are particularly preferred. It is also preferable to use a combination of two or more of these release agents. The amount of these modified silicone oils added is preferably 0.5% by mass or more and 30% by mass or less of the resin constituting the receiving layer.

  In the formation of the receiving layer, pigments and fillers such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, and fine powder silica are used for the purpose of improving the whiteness of the receiving layer and further enhancing the sharpness of the transferred image. Can be added. Moreover, you may add plasticizers, such as a phthalic acid ester compound, a sebacic acid ester compound, and a phosphoric acid ester compound.

The receiving layer is made of thermoplastic resin and other necessary additives such as mold release agents, plasticizers, fillers, crosslinking agents, curing agents, catalysts, heat release agents, UV absorbers, antioxidants, and light. Formed by applying and drying a coating solution in which a stabilizer or the like is dissolved or dispersed in an organic solvent or water by a forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate can do. The coating amount of the thus formed receptor layer is usually extent 0.5 g / ^{m 2} or more 50 g / ^{m 2} or less in the dry state, preferably 2 g / ^{m 2} or more 10 g / ^{m 2} or less.

(Release layer)
The thermal transfer image receiving sheet may further have a release layer on at least a part of the surface of the receiving layer. The release layer can be formed by applying the above release agent dissolved or dispersed in an appropriate solvent and then drying. Although it does not specifically limit as a mold release agent used for a mold release layer, The reaction hardened | cured material of an amino modified silicone oil and an epoxy modified silicone oil is preferable. The thickness of the release agent layer is preferably 0.01 μm or more and 5.0 μm or less, and more preferably 0.05 μm or more and 2.0 μm or less. When forming the receptor layer by adding silicone oil, the release layer can be formed even if the silicone oil bleed out on the surface after application is cured. In the formation of the receiving layer, pigments such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, and finely divided silica are used for the purpose of improving the whiteness of the receiving layer and further enhancing the sharpness of the transferred image. Fillers can be added. Further, a plasticizer such as a phthalic acid ester compound, a sebacic acid ester compound, and a phosphoric acid ester compound may be added.

(Hollow layer)
The hollow layer of the thermal transfer image-receiving sheet has heat insulation properties that can prevent heat applied during image formation by thermal transfer from being lost due to heat transfer to a substrate or the like. As the hollow layer, it is preferable to use a porous film having microvoids inside. The porous film is preferably a porous film containing a polyolefin resin, for example, a polypropylene resin or a polyethylene terephthalate resin as a base resin and having fine voids inside.

  As a method for producing fine voids in the film, a compound is prepared by kneading organic fine particles or inorganic fine particles (one kind or plural kinds) incompatible with the resin as the base of the film. Microscopically, this compound forms a fine sea-island structure with the base resin and fine particles incompatible with the base resin, and the compound is formed into a film and stretched to form the sea-island interface. The fine voids as described above are generated by the peeling of the film or the large deformation of the region forming the island.

  As a method for forming the fine voids, for example, a method in which polypropylene is mainly used and polyester or acrylic resin having a melting point higher than that of polypropylene is added thereto. In this case, polyester or acrylic resin serves as a nucleating agent that forms fine voids. In any case, the content of the polyester and acrylic resin is preferably 2 or more and 10 parts by mass or less with respect to 100 parts by mass of polypropylene. When the content is 2 parts by mass or more, fine voids can be sufficiently generated, and the printing sensitivity can be further improved. Moreover, when content is 10 mass parts or less, the heat resistance of a porous film can fully be ensured.

  Moreover, when producing the porous film which uses polypropylene as the base resin, it is preferable to further add polyisoprene in order to generate more fine and dense voids. Thereby, higher printing sensitivity can be obtained. For example, a porous film having high printing sensitivity can be obtained by preparing a compound composed mainly of polypropylene, blended with acrylic resin or polyester, and polyisoprene, forming a compound, and stretching.

(Primer layer)
The primer layer of the thermal transfer image-receiving sheet is provided between the receiving layer and the hollow layer. Adhesion between the receiving layer and the porous film, whiteness, cushioning property, concealing property, antistatic property, and anti-curling property The purpose of granting. In the present invention, any conventionally known primer layer can be provided. The binder resin used for the primer layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl chloride- Examples thereof include vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer resin, polyethylene resin, and polypropylene resin.

Moreover, it is preferable to add fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate in order to impart whiteness and concealment. Furthermore, stilbene compounds, benzimidazole compounds, and benzoxazole compounds are added as fluorescent brightening agents to enhance whiteness, and hindered amine compounds and hindered phenol compounds are used to increase the light fastness of printed materials. Add compounds, benzotriazole compounds, benzophenone compounds, etc. as UV absorbers or antioxidants, or add cationic acrylic resins, polyaniline resins, and various conductive fillers to impart antistatic properties can do. The coating amount of the primer layer is preferably about 0.5 g / m ² or more and 5 g / m ² or less in a dry state. The primer layer and the like may be applied by the same method as the receiving layer forming means.

<Method for producing thermal transfer image-receiving sheet>
The method for producing a thermal transfer image receiving sheet according to the present invention is a method for producing a thermal transfer image receiving sheet comprising a substrate, a receiving layer on one surface of the substrate, and a back resin layer on the other surface of the substrate. Then, while extruding the resin on the substrate, the resin is passed through a pair of rollers consisting of a satin roll and a nip roll so that the resin is in contact with the satin roll, and a back surface resin layer is formed on the substrate. It includes a process. The back resin layer is as described in detail above.

  One embodiment of the process of forming the back surface resin layer of the method for producing a thermal transfer image receiving sheet according to the present invention will be described with reference to the schematic view of FIG. First, the base material 11 is placed on the nip roll 21. Next, while melting and extruding the resin 23 from the die head 22 onto the base material 11, the base material 11 and the resin 23 are passed between the pair of satin roll 20 and the nip roll 21 so that the resin 23 is in contact with the satin roll 20. Then, the laminated sheet 25 having the back surface resin layer 12 formed on the substrate 11 is conveyed onto the guide roll 24.

  The surface roughness Ra of the satin roll used in the production method of the present invention is preferably 0.66 μm or more and 5.86 μm or less, more preferably 0.7 μm or more and 5.0 μm or more, and further preferably 0.9 μm or more. It is 4.0 μm or less, and more preferably 1.0 μm or more and 3.5 μm or less. The surface roughness Ra of the satin roll can be appropriately adjusted by a known process such as a sandblast process on the roll surface. Moreover, the temperature of the satin roll is preferably 100 to 130 ° C, more preferably 105 to 125 ° C, and still more preferably 110 ° C to 120 ° C. By using such a satin roll, a back resin layer having a desired surface roughness Ra can be formed.

  The production method of the present invention may further include a step of forming a surface resin layer and a step of forming a hollow layer, a primer layer, a receiving layer and the like on the surface resin layer. The order of the step of forming the surface resin layer and the step of forming the surface resin layer is not particularly limited. The surface resin layer, the hollow layer, the primer layer, and the receiving layer are as described in detail above.

  The method for producing a thermal transfer image-receiving sheet according to the present invention also comprises a substrate, a thermal transfer image-receiving sheet comprising a receiving layer on one surface of the substrate and a back resin layer on the other surface of the substrate. The method includes a step of embossing the back resin layer of the thermal transfer image-receiving sheet using a satin roll and adjusting the surface roughness Ra of the back resin layer to 0.65 μm or more and 1.14 μm or less. In this manufacturing method, the surface roughness Ra of the back surface resin layer can be adjusted after each layer such as the back surface resin layer and the receiving layer of the thermal transfer image receiving sheet is formed by a conventionally known method.

<Thermal transfer ink sheet>
The thermal transfer ink sheet used together with the thermal transfer image-receiving sheet of the present invention is a layer in which a heat transferable color material layer is provided on one side of a base sheet and a heat resistant slipping layer is provided on the other side of the base sheet. What has a structure is good. Hereinafter, each layer constituting the thermal transfer ink sheet will be described.

(Substrate sheet)
As the material of the base sheet constituting the thermal transfer ink sheet, conventionally known materials can be used, and even other materials can be used as long as they have a certain degree of heat resistance and strength. be able to. For example, polyethylene terephthalate, polyester, polypropylene, polycarbonate, polyethylene, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyimide, nylon, cellulose acetate, ionomer and other resin films, condenser paper, paraffin paper, and other non-woven fabrics Etc. These may be used alone, or a laminate in which these are arbitrarily combined may be used. Among these, polyethylene terephthalate which is a versatile plastic that can be thinned and is inexpensive is preferable.

  The thickness of the base sheet can be appropriately selected according to the material so that the strength, heat resistance and the like are appropriate, but usually it is preferably about 0.5 μm to 50 μm, more preferably 1 μm to 20 μm. More preferably, it is 1 μm or more and 10 μm or less.

  The base sheet may be subjected to a surface treatment in order to improve adhesion with an adjacent layer. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, and grafting treatment are applied. can do. Only one type of the surface treatment may be applied, or two or more types may be applied.

  Furthermore, it is also possible to apply and form an adhesive layer on the base sheet as an adhesive treatment of the base sheet. An adhesion layer can be formed from the following organic materials and inorganic materials, for example. Examples of the organic material include polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polyether resins, polystyrene resins, Examples thereof include polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl alcohol resins, polyvinyl pyrrolidone and vinyl resins such as modified products thereof, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral. Examples of the inorganic material include silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or hydrate, suspicion bakumaite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, oxidation Examples thereof include ultrafine particles of colloidal inorganic pigments such as magnesium and titanium oxide.

  Moreover, when manufacturing a plastic film by extending | stretching as said surface treatment, a primer liquid can be apply | coated to an unstretched film and it can also carry out by extending | stretching after that (primer process).

(Heat transferable color material layer)
The thermal transfer ink sheet is provided with a thermal transfer color material layer on one surface of a base sheet. When the thermal transfer ink sheet is a sublimation type thermal transfer ink sheet, a layer containing a sublimation dye is formed as the thermal transferable color material layer, and when the thermal transfer type thermal transfer ink sheet is a hot melt composition containing a colorant A layer containing a heat-meltable ink is formed. A layer region containing a sublimable dye and a layer region containing a heat-meltable ink composed of a heat-melting composition containing a colorant are provided in a surface sequence on a continuous base sheet. Also good.

  As the material of the heat transferable color material layer, conventionally known dyes can be used, but those having good characteristics as a printing material, for example, having a sufficient coloring density and changing color due to light, heat, temperature, etc. Preferred are diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenone azomethine, pyrazoloazomethine, imidazolazomethine, imidazoazomethine, pyridone Azomethine dyes such as azomethine, xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acridine dyes, benzeneazo dyes, pyridoneazo, thiophenazo, iso Thiazoleazo, pyro Azo dyes such as ruazo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, and disazo, spiropyran dyes, indolinospiropyran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes, quinophthalone dyes And dyes. Specifically, red dyes such as Disperse Red 60, Disperse Violet 26, CeresRed 7B, Samaron Red F3BS, yellow dyes such as Disperse Yellow 231, PTY-52, Macrolex Yellow 6G, Solvent Blue 63, Waxolin Blue AP-FW, Holon Brilliant Blue S-R, MS Blue 100, C.I. I. And blue dyes such as Solvent Blue 22. In addition, the dye contained in the ribbon used by the sublimation type thermal transfer system marketed can also be used.

  Examples of the binder resin for supporting the dye include cellulose resins such as ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, and cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetate resin, and polyvinyl butyral resin. And vinyl resins such as polyvinyl acetal resin and polyvinyl pyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, and polyester resins. Among these, cellulose-based, vinyl-based, acrylic-based, polyurethane-based, and polyester-based resins are preferable from the viewpoints of heat resistance, dye transferability, and the like.

  Examples of the method for forming the heat transferable color material layer include the following methods. For the heat-transferable colorant layer obtained by adding additives such as a release agent to the dye and binder resin as necessary, dissolving in an appropriate organic solvent such as toluene and methyl ethyl ketone, or dispersing in water. A coating solution (dissolved solution or dispersion) is applied to one surface of a substrate sheet by, for example, a gravure printing method, a reverse roll coating method using a gravure plate, a roll coater, a bar coater, etc., and dried. Can be formed. The heat transferable color material layer has a thickness of about 0.2 μm or more and 5.0 μm or less, and the content of the sublimable dye in the heat transferable color material layer is 5 mass% or more and 90 mass% or less, preferably 5 It is preferable that they are mass% or more and 70 mass% or less.

(Protective layer)
The thermal transfer ink sheet may be provided with a protective layer in the surface order on the same side as the thermal transferable color material layer. After the color material is transferred to the thermal transfer image-receiving sheet, the protective layer is transferred to cover the image, whereby the image can be protected from light, gas, liquid, abrasion and the like. Other layers such as an adhesive layer, a release layer, or an undercoat layer may be provided as a protective layer.

(Heat resistant slipping layer)
The heat resistant slipping layer is mainly composed of a heat resistant resin. The heat resistant resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyether resin, polybutadiene resin, styrene-butadiene copolymer resin, Acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, cellulose acetate-hydrodiene Phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, Fine chlorinated polyolefin resins.

  The heat resistant slipping layer may be formed by blending additives such as a slipperiness imparting agent, a crosslinking agent, a release agent, an organic powder, and an inorganic powder in addition to the above heat resistant resin.

  In general, the heat-resistant slipping layer is prepared by adding the above-mentioned heat-resistant resin and the above-mentioned slipperiness-imparting agent and additives that are optionally added to the solvent, and dissolving or dispersing each component to form a heat-resistant slipping layer coating solution. After the preparation, the heat resistant slipping layer coating solution can be applied on a substrate and dried. As the solvent in the heat resistant slipping layer coating solution, the same solvents as those in the dye ink can be used.

Examples of the coating method of the heat resistant slipping layer coating liquid include wire bar coating, gravure printing, screen printing, reverse roll coating using a gravure plate, and gravure coating is particularly preferable. The heat resistant slipping layer coating solution may be applied so that the dry coating amount is preferably 0.1 g / m ² or more and 3 g / m ² or less, more preferably 1.5 g / m ² or less.

<Image forming method>
In the image forming method using the thermal transfer image receiving sheet of the present invention, the thermal transfer ink receiving sheet is superposed on a thermal transfer ink sheet containing a heat diffusible dye, and heated in accordance with a recording signal. An image can be formed by transferring the contained heat diffusible dye to the thermal transfer image-receiving sheet.

  As a thermal transfer recording apparatus that can be used in such an image forming method, a known apparatus can be used and is not particularly limited. In the present invention, a commercially available thermal transfer recording apparatus can be used, and examples thereof include a sublimation thermal transfer printer (manufactured by ALTECH ADS (model: MEGAPICEL III), manufactured by DNP Photo Lucio (model: DS40)).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples.

[Example 1]
As a base material layer, a white base paper (thickness 150 μm, manufactured by Mitsubishi Paper Industries Co., Ltd.), which is a paper base material, was prepared, and an apparatus including a pair of satin roll and nip roll as shown in FIG. The base material was placed on the nip roll side, while the polyethylene resin was melt extruded from the die head onto the paper base material, the paper base material and the polyethylene resin were passed so that the polyethylene resin was in contact with the satin roll, and the back surface resin was placed on the base material. The surface roughness Ra of the back surface resin layer was measured using a surface roughness measuring instrument (trade name: Surfcom, manufactured by Tokyo Seimitsu Co., Ltd.) and found to be 0.71 μm. The surface roughness Ra of the roll was 0.73 μm.

  A polyethylene resin was melt-extruded on the opposite surface of the base material on which the back surface resin layer was formed to form a surface resin layer. Subsequently, a hollow layer coating solution, a primer layer coating solution, and a receiving layer coating solution having the following composition are applied with a gravure coater and dried at 110 ° C. to form a hollow layer, a primer layer, and a receiving layer. Thus, a thermal transfer image receiving sheet was obtained.

(Composition of coating solution for hollow layer)
・ Hollow particles (volume average particle size: 0.5 μm, average hollow ratio: 45%, manufactured by Rohm and Haas Co., Ltd., trade name: Ropeke ST) 59 parts by mass ・ Gelatin (made by Nitta Gelatin Co., Ltd., trade name) : N1236) 28 parts by mass binder resin (styrene / acrylic resin, manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: New Coat B-13) 5 parts by mass binder resin (styrene / acrylic resin, BASF Japan Ltd.) Product name: Jonkrill 62J) 8 parts by mass

(Composition of primer layer coating solution)
Polyester resin (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: WR-905) 13.1 parts by mass Titanium oxide (manufactured by Tochem Products Co., Ltd., trade name: TCA-888) 26.2 parts by mass Brightening agent (benzimidazole derivative, manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Ubitex BAC) 0.39 parts by mass / water / isopropyl alcohol [IPA] (mass ratio 2/1) 60 parts by mass

(Composition of coating solution for receiving layer)
・ Vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Solvain C)
60 parts by mass / epoxy-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-3000T)
1.2 parts by mass / methylstil modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: 24-510)
0.6 parts by mass / methyl ethyl ketone / toluene (mass ratio 1/1) 5 parts by mass

[Example 2]
A back surface resin layer was formed in the same manner as in Example 1 except that the surface roughness Ra of the satin roll was changed to 1.03 μm. Subsequently, in the same manner as in Example 1, a surface resin layer, a hollow layer, a primer layer, and a receiving layer were formed to obtain a thermal transfer image receiving sheet. The surface roughness Ra of the back surface resin layer was 0.75 μm.

[Example 3]
A back surface resin layer was formed in the same manner as in Example 1 except that the surface roughness Ra of the satin roll was changed to 3.14 μm. Subsequently, in the same manner as in Example 1, a surface resin layer, a hollow layer, a primer layer, and a receiving layer were formed to obtain a thermal transfer image receiving sheet. The surface roughness Ra of the back resin layer was 0.89 μm.

[Comparative Example 1]
A back resin layer was formed in the same manner as in Example 1 except that the satin roll was changed to a mirror roll (surface roughness Ra: 0.65 μm). Subsequently, in the same manner as in Example 1, a surface resin layer, a hollow layer, a primer layer, and a receiving layer were formed to obtain a thermal transfer image receiving sheet. The surface roughness Ra of the back surface resin layer was 0.64 μm.

[Comparative Example 2]
A back surface resin layer was formed in the same manner as in Example 1 except that the surface roughness Ra of the satin roll was changed to 5.87 μm. Subsequently, in the same manner as in Example 1, a surface resin layer, a hollow layer, a primer layer, and a receiving layer were formed to obtain a thermal transfer image receiving sheet. The surface roughness Ra of the back resin layer was 1.15 μm.

[Evaluation of thermal transfer image-receiving sheet]
The thermal transfer image-receiving sheets prepared in the above-described examples and comparative examples were subjected to (1) appearance, (2) writability evaluation, (3) glue adhesion evaluation, and (4) separation evaluation.

(1) Appearance evaluation The appearance on the back side of the thermal transfer image-receiving sheet was visually evaluated. The evaluation criteria are as follows.
[Evaluation criteria]
○: At first glance, no roughness was recognized.
X: Roughness was recognized at first glance.

(2) Writability evaluation Writing to the back surface resin layer of the thermal transfer image-receiving sheet with an oil-based ballpoint pen was performed, and it was visually confirmed whether the written characters were rubbed by rubbing with a finger after 1 minute. The evaluation criteria are as follows.
[Evaluation criteria]
○: Characters did not fade when rubbed with a finger.
X: Characters were faint when rubbed with fingers.

(3) Adhesive adhesive evaluation Various pastes (Pritt (registered trademark), Glue, Arabic Yamato (registered trademark), Pit (registered trademark), Fuchi glue, one-yen stamp) are applied on the back layer of the thermal transfer image-receiving sheet. It was pasted on plain paper, peeled off after 24 hours, and evaluated for adhesiveness according to the following evaluation criteria. [Evaluation criteria]
○: Not peeled off in all glues.
(Triangle | delta): It peels easily in all the glues or one part glue.
X: It does not stick in all glues or some glues.

(4) Evaluation of judgment property Using the thermal transfer image-receiving sheet prepared above, 100 natural images were printed with a sublimation transfer printing system “Print Center (DNP Photo Lucio Co., Ltd.)”, and the prints were aligned. The ease was sensory evaluated.
[Evaluation criteria]
○: Can be easily aligned, and has good judgment.
(Triangle | delta): It can arrange, and the judgment property was normal.
X: It was not able to arrange, and the judgment property was unsatisfactory.

The results of the above evaluations are shown in Table 1. It has been found that the thermal transfer image-receiving sheet of the example satisfying the configuration of the present invention is superior in appearance, writing property, glue adhesiveness, and judgment as compared with the thermal transfer image-receiving sheet of the comparative example.

DESCRIPTION OF SYMBOLS 10 Thermal transfer image receiving sheet 11 Base material 12 Back surface resin layer 13 Receiving layer 14 Primer layer 15 Hollow layer 16 Surface resin layer 20 Pear surface roll 21 Nip roll 22 Die head 23 Resin 24 Guide roll

Claims (9)

A thermal transfer image receiving sheet comprising a substrate, a receiving layer on one surface of the substrate, and a back resin layer on the other surface of the substrate,
The thermal transfer image receiving sheet, wherein the back surface resin layer has a surface roughness Ra of 0.65 μm or more and 1.14 μm or less.   The thermal transfer image receiving sheet according to claim 1, further comprising a hollow layer between the substrate and the receiving layer.   The thermal transfer image receiving sheet according to claim 2, further comprising a primer layer between the hollow layer and the receiving layer.   The thermal transfer image receiving sheet according to claim 2, further comprising a surface resin layer between the base material and the hollow layer.   The thermal transfer image receiving sheet according to any one of claims 1 to 4, wherein the back surface resin layer contains a polyolefin resin. A method for producing a thermal transfer image receiving sheet, comprising a base material, a receiving layer on one surface of the base material, and a back surface resin layer on the other surface of the base material,
While extruding the resin onto the base material, the resin is passed between the pair of satin rolls and nip rolls so that the resin is in contact with the satin rolls, and the surface roughness Ra is 0.65 μm or more and 1.14 μm or less. The manufacturing method of a thermal transfer image receiving sheet including the process of forming a back surface resin layer on the said base material. A method for producing a thermal transfer image receiving sheet, comprising a base material, a receiving layer on one surface of the base material, and a back surface resin layer on the other surface of the base material,
A method for producing a thermal transfer image receiving sheet, comprising a step of embossing a back surface resin layer of the thermal transfer image receiving sheet using a satin roll and adjusting a surface roughness Ra of the back surface resin layer to 0.65 μm or more and 1.14 μm or less. .   The manufacturing method of the thermal transfer image receiving sheet of Claim 6 or 7 whose surface roughness Ra of the said satin roll is 0.66 micrometer or more and 5.86 micrometers or less.   The manufacturing method of the thermal transfer image receiving sheet as described in any one of Claims 6-8 whose temperature of the said satin roll is 100-130 degreeC.

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