JP2009090516A - Thermal transfer image receiving sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer image receiving sheet which prevents the effects caused by the friction between the thermal transfer image receiving sheets, has an excellent writing suitability and adhesion to stamps in its back side, has a good anti-static function during the feeding, causes no troubles such as double feeding or jamming during the feeding or printing by a thermal transfer printer, and has a right slipperiness, demoldability, and contamination resistance on the back side layer. <P>SOLUTION: The thermal transfer image receiving sheet including a dye receiving layer on at least one surface of the base sheet has a back surface layer containing a thermoplastic resin, cellulose filler, anti-static additive, and lubricant on the base sheet surface opposite of the surface with the dye receiving layer deposited thereon, thereby solving the problem. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal transfer image-receiving sheet, more specifically, in a thermal transfer image-receiving sheet provided with a sublimable dye-receiving layer on at least one surface of a base material sheet, preventing the influence on the image-receiving surface due to friction between thermal transfer image-receiving sheets, Excellent transferability on the back side of the thermal transfer image-receiving sheet and adhesiveness such as stamps, and antistatic performance during transport. Troubles during transport such as double feeding and jamming when feeding or printing with a thermal transfer printer. The present invention relates to a thermal transfer image-receiving sheet having moderate slipping property, releasability and stain resistance in the back layer.

  Conventionally, in a thermal transfer image receiving sheet, a color material receiving layer is provided on the surface to improve the acceptability and retention of a color material such as a dye, and at the same time, the back side of the thermal transfer image receiving sheet is transported such as automatic paper supply and discharge in a printer. In order to improve the performance, to prevent the thermal transfer sheet and the image-receiving sheet from being fused when the image-receiving sheet is inserted into the printer by mistake, and when the image-receiving sheet after printing is stored in an overlapping manner In addition, for the purpose of preventing dyes, etc. from moving to the back side and lowering the image density on the front side or contaminating the back side, the back side is provided with appropriate slipperiness, releasability and stain resistance. It has been practiced to provide a back surface layer for this purpose.

  In recent years, the need to use the thermal transfer image-receiving sheet as a postcard such as a picture postcard has increased, and on the surface of the image-receiving sheet, for example, a color image such as a photograph is thermally transferred, and on the back surface, in addition to the above performance, In order to write an address, a sent message, or affix a stamp, it has become necessary to add writing ability and adhesiveness to the stamp. As a method for meeting such needs, for example, Patent Document 1 proposes a thermal transfer image-receiving sheet containing polyvinyl butyral resin and hydrophilic porous microsilica as a back layer. Patent Document 2 discloses a thermal transfer image receiving sheet in which the back layer contains nylon resin particles, barium sulfate, and a higher fatty acid salt. Moreover, in patent document 3, it is shown that a back surface layer contains a cellulose acetate resin and micro silica as a main component.

  In these patent documents, an inorganic filler such as silica or barium sulfate is included in the outermost surface of the back surface layer. However, the friction between the heat transfer image receiving sheets is strong due to the paper supply / discharge in the printer, and the influence on the image receiving surface ( Image quality such as streaks and unevenness) is likely to occur. Moreover, in patent document 4, the hydrophilic porous layer which has a thermoplastic resin and a hydrophilic porous particle as a main component as a 1st layer is formed in the back surface side of the base material sheet | seat of a thermal transfer image receiving sheet, and also on it. A layer in which a back coating layer containing a polyvinyl acetal resin, a silicone-modified acrylic resin and nylon resin particles is formed as a second layer has been proposed. However, the thermal transfer image-receiving sheet shown in Patent Document 4 is not satisfactory in writing ability and adhesiveness of stamps, and is manufactured in order to provide two layers containing particles on the back surface of the substrate. There is a problem with low productivity.

The present applicant has filed in Japanese Patent Application No. 2006-325411 the content of containing a thermoplastic resin and a cellulose filler in the back layer of the thermal transfer image-receiving sheet, eliminating the influence on the image-receiving surface due to friction between the thermal transfer image-receiving sheets, and writing suitability. It has excellent adhesive properties such as stamps, etc., but the antistatic performance of the back layer is not good, and it has been found that problems such as double feeding and jamming occur when feeding and printing with a thermal transfer printer. .
JP-A-9-175048 JP 2000-335120 A JP-A-8-244362 JP 2002-337463 A

  Therefore, in order to solve the above problems, the influence of the friction between the thermal transfer image receiving sheets on the image receiving surface is prevented, the back side of the thermal transfer image receiving sheet is excellent in writing ability and adhesiveness such as stamps, and antistatic performance in conveyance. Thermal transfer image-receiving sheet with good slippage, release property, and contamination resistance in the back layer, with no problems in transport such as double feeding or jamming when feeding or printing with a thermal transfer printer The purpose is to provide.

  The invention according to claim 1 is a thermal transfer image-receiving sheet in which a dye-receiving layer is formed on at least one surface of a substrate sheet, on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed, A back layer containing a thermoplastic resin, a cellulose filler, an antistatic agent and a slip agent is formed. The invention according to claim 2 is characterized in that a back surface intermediate layer is formed between the base material sheet according to claim 1 and the back surface layer.

  The thermal transfer image-receiving sheet of the present invention has a dye-receiving layer formed on at least one surface of the substrate sheet, and a thermoplastic resin and a cellulose filler on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed, By having a back surface layer containing an antistatic agent and a slip agent, it is particularly excellent in writing ability on the back side and adhesiveness such as stamps, and has good antistatic performance in transportation, and is supplied by a thermal transfer printer. There is no trouble in transport such as double feeding or jamming at the time of paper or printing, and moderate slipperiness and releasability in the back layer (the thermal transfer sheet when the front and back of the thermal transfer image receiving sheet are mistakenly inserted into the printer) Releasability), stain resistance, and the friction between the thermal transfer image receiving sheets, the influence on the image receiving surface due to rubbing between the back layer and the dye receiving layer (decrease in image quality such as streaks and unevenness) I was able to stop.

Hereinafter, each layer constituting the thermal transfer image receiving sheet of the present invention will be described in detail.
(Substrate sheet)
As the base sheet used in the present invention, synthetic paper (polyolefin, polystyrene, etc.), fine paper, art paper, coated paper, cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex Various plastic films or sheets such as impregnated paper, synthetic resin internal paper, cellulose fiber paper such as paperboard, polyolefin (polyethylene, polypropylene, etc.), polystyrene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, polymethacrylate, etc. can be used. In addition, a white opaque film formed by adding a white pigment or a filler to these synthetic resins, or a film having fine voids (microvoids) inside the substrate can be used, and is not particularly limited. Moreover, the laminated body by the arbitrary combinations of the said base material sheet can also be used.

  Examples of typical laminates include a laminate of cellulose fiber paper and synthetic paper, or cellulose fiber paper and a plastic film or sheet. The thickness of these base material sheets may be arbitrary, for example, the thickness of about 10-300 micrometers is common. When the base sheet as described above has poor adhesion to the receiving layer formed on the surface thereof, it is preferable to subject the surface to easy adhesion treatment such as primer treatment, corona discharge treatment or plasma treatment. Further, the thermal transfer image receiving sheet of the present invention can be applied to various uses such as a thermal transfer sheet capable of thermal transfer recording, cards, and a transmissive original document sheet by appropriately selecting a substrate sheet.

(Dye-receiving layer)
The dye receiving layer in the thermal transfer image receiving sheet of the present invention is for receiving the sublimation dye transferred from the thermal transfer 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-vinyl acetate Examples include 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 of the present invention can contain a release agent in the receiving layer in order to improve the releasability from the thermal transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine-based or phosphate-based surfactant, silicone oil, various silicone resins, and the like, but silicone oil is preferable. .

  Examples of the silicone oil include epoxy-modified silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, phenyl-modified silicone oil, vinyl-modified silicone oil, polyether-modified silicone oil, and hydrogen-modified silicone oil. Silicone oil and catalyst-curing silicone oil are preferred. The release agent is preferably added so as to be about 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin constituting the receiving layer.

  Further, the release agent layer can be provided by applying the above release agent dissolved or dispersed in a suitable solvent on a part of the surface of the receiving layer, followed by drying. As the release agent constituting the release agent layer, the reaction cured product of the amino-modified silicone oil and the epoxy-modified silicone oil described above is particularly preferable, and the thickness of the release agent layer is 0.01 to 5.0 μm, particularly 0.05-2.0 micrometers is preferable. When forming the receptor layer by adding silicone oil, the release agent 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, fine powder silica and the like are used for the purpose of improving the whiteness of the receiving layer and further enhancing the clarity of the transferred image. Fillers can be added. Further, a plasticizer such as a phthalic acid ester compound, a sebacic acid ester compound, or a phosphoric acid ester compound may be added.

The thermal transfer image-receiving sheet of the present invention has a thermoplastic resin as described above and other necessary additives such as a mold release agent, a plasticizer, a filler, a crosslinking agent, and a curing agent on at least one surface of the base sheet. , A catalyst, a heat release agent, an ultraviolet absorber, an antioxidant, a light stabilizer, and the like are dissolved in a suitable organic solvent, or a dispersion dispersed in an organic solvent or water is used, for example, a gravure printing method It is obtained by applying and drying by a forming means such as a screen printing method or a reverse roll coating method using a gravure plate to form a dye receiving layer. Application of an intermediate layer, a back surface layer, a back surface intermediate layer, and the like, which will be described later, is also performed by the same method as that for forming the dye receiving layer. The coating amount of the thus formed are dye-receiving layer, usually, 0.5 to 50 g / m ² approximately in the dry state, preferably 2 to 10 g / m ^2. Such a dye-receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating.

(Middle layer)
Between the receiving layer and the substrate sheet, any conventionally known intermediate is used to provide adhesion, whiteness, cushioning, concealing property, antistatic property, anti-curling property, etc. between the receiving layer and the substrate sheet. A layer can be provided. Binder resin used in the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid Examples include vinyl copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, epoxy resins, cellulose resins, ethylene-vinyl acetate copolymer resins, polyethylene resins, polypropylene resins, and the like. Of these, those having an active hydroxyl group can further be used as a cured product thereof.

Moreover, it is preferable to add fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate in order to impart whiteness and concealability. Furthermore, stilbene compounds, benzimidazole compounds, benzoxazole compounds, etc. are added as fluorescent brighteners to enhance whiteness, and hindered amine compounds, hindered phenol compounds to enhance the light fastness of printed materials. Benzotriazole compounds, benzophenone compounds, etc. may be added as UV absorbers or antioxidants, or cationic acrylic resins, polyaniline resins, various conductive fillers, etc. may be added to impart antistatic properties. it can. The coating amount of the intermediate layer is preferably about 0.5 to 30 g / m ^{2 in} a dry state.

(Back layer)
In the thermal transfer image receiving sheet of the present invention, a back layer is provided on the surface of the base sheet opposite to the surface on which the dye receiving layer is provided. The back layer of the present invention has a writing ability and adhesiveness such as stamps, and has antistatic performance, moderate slipperiness, and releasability (with the thermal transfer sheet when the front and back of the thermal transfer image-receiving sheet are inserted into the printer by mistake. Image receiving surface due to rubbing between the back layer and the dye receiving layer due to friction between the thermal transfer image receiving sheets. The effect on the image quality (decrease in image quality such as streaks and unevenness) is prevented. The structure of the back surface layer exhibiting this function contains a cellulose filler, an antistatic agent and a slip agent, and a thermoplastic resin as a binder resin.

  The cellulose filler contained in the back layer is a kind of carbohydrate, which is a main component of plant cells and fibers, and is a powder of cellulose, which is a natural polymer substance. It does not dissolve in water or hot water. The cellulose filler used in the present invention preferably has an average particle size of 5 to 20 μm. When the particle size is too small, the drying property in writing of water-based ink or the like is lowered, and the slipping property and the release property are likely to be lowered. On the other hand, if the particle size is too large, bleeding tends to occur at the time of writing, or the influence of image quality degradation such as streaks or unevenness on the image receiving surface due to rubbing between the back surface layer and the dye receiving layer tends to occur. Regarding the average particle size of the cellulose filler in the present invention, the average particle size was calculated on the basis of a volume based on a laser diffraction scattering method (microtrack method), and specifically measured with a microtrack particle size distribution measuring device manufactured by Nikkiso Co., Ltd. Is.

  The ratio of adding the cellulose filler in the back layer is preferably 0.5 to 3.0 in terms of the weight ratio of cellulose filler / thermoplastic resin to the thermoplastic resin of the binder resin in the back layer. When the addition ratio of the cellulose filler is too small, the drying property in writing of water-based ink or the like is lowered, and the slipping property and the release property are likely to be lowered. On the other hand, if the cellulose filler is added too much, the film strength of the back layer is lowered, the fixability of the ink to be written is lowered, or the ink to be written is liable to spread.

  The thermoplastic resin that is the binder resin in the back layer includes resins such as polyvinyl acetal, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl butyral, cellulose acetate, nitrile cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, starch, gelatin, and water-soluble Examples thereof include acrylic resins, water-soluble polyester resins, water-soluble urethane resins, mixtures and copolymers thereof, and vinyl acetate resin emulsions and vinyl chloride-vinyl acetate copolymer resin emulsions. In the back layer of the present invention, among the above binder resins, polyvinyl alcohol, water-soluble acrylic resin, water-soluble polyester resin, and water-soluble urethane resin are preferable because they easily exhibit the functions of the back layer such as writing suitability.

  As the antistatic agent in the back layer, a cationic polymer or anionic polymer that is an ion conductive antistatic agent, a conductive needle crystal that is an electronic conductive antistatic agent, or a conductive layered silicate is preferably used. This is because an excellent antistatic function can be exhibited without impairing the functions of components other than the antistatic agent contained in the back surface layer, that is, the components of the cellulose filler, the slip agent, and the thermoplastic resin. As the anionic polymer, known ones can be used, and in particular, an alkali salt of polystyrene sulfonic acid and a sodium salt of polyacrylic acid (for example, polyacrylic acid, polymethacrylic acid, sodium salt of poly-α-ethylacrylic acid). Polymerized acrylic acids such as potassium polyacrylate, sodium salt of acrylic acid and methyl acrylate copolymer, and alkali salts of acrylic acid copolymer, etc. are preferred, and the surface of the back layer does not ooze and is wound up There is no blocking in the state. Among the above-mentioned copolymers, as an alkali salt of polystyrene sulfonic acid, for example, there is one commercially available under the trade name of Chemistat 6120 manufactured by Sanyo Chemical Industries, Ltd. and can be obtained.

  As the cationic polymer, known ones can be used, and in particular, a cationic polymer obtained by copolymerization of styrene, vinyl chloride ammonium chloride, and each monomer of vinyl benzyl amine quaternary salt is preferable. It does not ooze out and does not cause blocking in the wound state. Each monomer of vinylbenzyl ammonium chloride and vinylbenzyl amine quaternary salt is organic or inorganic such as vinylbenzyl boron, magnesium, calcium, zinc, chromium, aluminum, iron, cobalt, nickel and titanium. The acid salt may be changed. In the above, the graft and / or block polymer of the polymer chain of the styrene and vinylbenzyl salt has been described. Instead of the styrene polymer chain, a polyolefin polymer chain, a polyester polymer chain, an epoxy polymer chain, and Grafted and / or block polymer cationic polymers can be used with any of the urethane polymer chains.

  A cationic acrylic resin can be used as the cationic polymer. Examples of the cationic acrylic resin include monomers having reactive groups such as carboxyl groups and hydroxyl groups such as acrylic acid, methacrylic acid, or mono (meth) acrylates of glycols such as ethylene glycol with these acids. Reactivity of glycidyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltriethanolammonium chloride, glycidyltrimethylammonium chloride, glycidyldimethylbenzylammonium chloride, glycidyldimethylbutylammonium chloride Monomers or copolymers obtained by reacting quaternary ammonium salts, or copolymers with other monomers can be mentioned. As such a cationic acrylic resin, various products can be obtained and used under the trade name of Electon from Soken Chemical Co., Ltd., for example. Such a cationic polymer can be used by being added in an amount of 10% by mass to 200% by mass with respect to the thermoplastic resin as a binder for the back layer.

The conductive needle crystal as the antistatic agent can be obtained by treating the surface of the needle crystal with a conductive agent. Examples of the acicular crystal include potassium titanate, titanium oxide, aluminum borate, silicon carbide, silicon nitride and the like. TiO ₂ -based compounds are preferred from the viewpoint of coloring in white, and it is necessary to consider the stability against dispersion, but TiO ₂ has a high hardness and is very excellent in terms of the stability of conductivity with respect to dispersion strength. It is preferable. When the hardness is low, crystals are broken at the time of dispersion, resulting in a decrease in conductivity and a problem that the conductivity is changed due to a slight variation in dispersion at the time of coating. As the conductive agent, SnO ₂ / Sb, InO ₃ / Sn, and ZnO / Al are generally known and can be used. However, considering conductivity, stability, cost, etc., SnO ₂ / Sb The system is particularly preferred.

  Factors affecting the conductivity include the size and amount of conductive needle crystals. As the conductive acicular crystals, those having a fiber diameter of 0.05 to 3 μm, a fiber length of 1 to 200 μm, and an aspect ratio of 10 to 200 are generally used. The higher the aspect ratio, the more advantageous the conductivity. Yes, sufficient conductivity can be obtained with a small addition amount, but from the viewpoint of dispersibility, stability and coating suitability, the fiber diameter is 0.1 to 1.0 μm, the fiber length is 1 to 20 μm, and the aspect ratio is 10 to 50. More preferably, the fiber diameter is 0.1 to 0.3 μm, the fiber length is 1 to 6 μm, and the aspect ratio is 10 to 20. As such a conductive needle crystal, for example, it can be obtained and used under the brand name FT-3000 manufactured by Ishihara Sangyo Co., Ltd. The aspect ratio is the fiber length / fiber diameter. The addition amount of the conductive needle-like crystal can be added up to about 1% by mass to 500% by mass with respect to the resin binder, but if it is too small, stable conductivity cannot be obtained, and it is too much. In some cases, it is disadvantageous in terms of cost, and coloring problems may occur.

  Moreover, the conductive layered silicate salt as an antistatic agent can also be used. Conductive layered silicate is a compound obtained by reacting sodium, magnesium and lithium salts with sodium silicate under appropriate conditions. The particle size is preferably 30 nm or less. For example, it can be obtained and used under the trade name of Laponite S, JS, Nippon Silica Kogyo Co., Ltd. As addition amount, 20 mass%-200 mass% are preferable with respect to the resin binder, Furthermore, 50 mass%-200 mass% are the most preferable. The back layer can be used as an antistatic agent by using one or a combination of two or more of the above cationic polymers, conductive needle crystals, and conductive layered silicate.

  In the back layer, in addition to the above cellulose filler, antistatic agent and thermoplastic resin, as a slip agent, at least one selected from polyolefin resin, polyamide resin, zinc stearate, silica, calcium carbonate, kaolin, etc. By including the filler, the sliding property such as automatic paper feeding and discharging in the printer and the releasability from the thermal transfer sheet when the front and back of the thermal transfer image receiving sheet are erroneously inserted into the printer are improved. Examples of the polyolefin resin include polyethylene wax and polypropylene wax, which can be used. When the filler selected from the above polyolefin resin, polyamide resin, zinc stearate, silica, calcium carbonate, and kaolin is contained in the back layer, only one kind of the above various fillers may be contained, or polyethylene wax and polyamide resin It is also possible to contain two or more different types of fillers that contain each filler.

In the above-mentioned various additives, the filler of polyethylene wax and zinc stearate is excellent in releasability from the thermal transfer sheet particularly when the front and back sides of the thermal transfer image receiving sheet are mistakenly inserted into the printer. In addition, each filler of polyamide resin, silica, calcium carbonate, and kaolin is excellent in slipperiness such as automatic paper supply / discharge in a printer. The above-mentioned cellulose filler, antistatic agent and slip agent, and the back layer containing a thermoplastic resin as a binder resin are usually applied in a dry state of about 0.1 to 20 g / m ² , preferably about 0.000. 5 to 10 g / m ² .

(Back layer)
In the thermal transfer image-receiving sheet of the present invention, a back surface intermediate layer can be provided between the base material sheet and the back surface layer, if necessary, when the adhesion between the both is low. Any conventionally known intermediate layer can be provided for the purpose of imparting adhesiveness, whiteness, cushioning property, concealing property, antistatic property, anticurling property, etc. between the back surface layer and the substrate sheet. Binder resin used in the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid Examples thereof include vinyl copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, epoxy resins, cellulose resins, ethylene-vinyl acetate copolymer resins, polyethylene resins, and polypropylene resins.

Among the binder resins described above, for the binder resin having an active hydroxyl group, an isocyanate can be further added to use the cured isocyanate as a binder. The coating amount of the back surface intermediate layer is preferably about 0.5 to 30 g / m ^{2 in} a dry state.

Next, an Example and a comparative example are given and this invention is further explained in full detail. In the text, “part” or “%” is based on mass unless otherwise specified.
(Example 1)
As a base material sheet, on a transparent polyethylene terephthalate film (Lumirror T60, # 25, manufactured by Toray Industries, Inc.), an intermediate layer coating solution having the following composition is wire bar coated to a dry coating amount of 2.0 g / m ² . The intermediate layer was formed by coating and drying. On the intermediate layer, a dye receptive layer coating solution having the following composition was applied by wire bar coating so that the dry coating amount was 4.0 g / m ² and dried to form a dye receptive layer.

<Intermediate layer coating solution>
Polyurethane resin (Nippon Polyurethane Industry Co., Ltd., NIPPON 5199) 25.0 parts Titanium oxide (Tochem Products, TCA-888) 75.0 parts Methyl ethyl ketone / toluene (mass ratio 1: 1) 400.0 parts

<Dye-receiving layer coating solution>
Vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., Solvein C) 100.0 parts Epoxy-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-3000T) 5.0 parts methyl ethyl ketone / Toluene (mass ratio 1: 1) 400.0 parts

On the other surface of the base sheet on which the intermediate layer and the dye receiving layer are formed, a back surface intermediate layer coating solution having the following composition is coated by wire bar so that the dry coating amount is 2.0 g / m ^2. Application and drying were carried out to form a back surface intermediate layer. On the back surface intermediate layer, a back surface layer coating solution having the following composition was applied by wire bar coating to a dry coating amount of 3.0 g / m ² and dried to form a back surface layer. 1 thermal transfer image-receiving sheet was prepared.

<Back surface intermediate layer coating solution>
Polyurethane resin (manufactured by Nippon Polyurethane Industry Co., Ltd., Nippon Run 5199) 5 parts Isocyanate curing agent (Mitsui Chemicals Polyurethane Co., Ltd., Takenate A-14) 10 parts Methyl ethyl ketone / toluene / isopropyl alcohol (mass ratio 2: 2: 1) 70 copies

<Back layer coating solution 1>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 25.0 parts Polyethylene wax dispersion 0.8 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.32 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemistat 6120, solid content 30.4%, polystyrene sulfonate alkali salt as the main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.12 parts The average particle diameter of the polyethylene wax dispersion is measured by a Coulter counter method, and the polyethylene wax dispersion and polypropylene described below are used. The average particle size of the wax dispersion was measured by the Coulter counter method.

(Example 2)
A thermal transfer image receiving sheet of Example 2 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 2>
2.50 parts of acrylic ester resin (Jurimer AT-613, manufactured by Nippon Pure Chemicals Co., Ltd.) 1.25 parts of polyethylene wax dispersion (manufactured by Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
2.06 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemist 6120, solid content 30.4%, polystyrene sulfonic acid alkali salt as the main component)
2.50 parts of cellulose filler (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 25.03 parts

(Example 3)
A thermal transfer image receiving sheet of Example 3 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 3>
Polyester resin (Toyobo Co., Ltd., Vylonal MD1480) 2.50 parts Polyethylene wax dispersion 1.25 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
2.06 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemist 6120, solid content 30.4%, polystyrene sulfonic acid alkali salt as the main component)
2.50 parts of cellulose filler (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 25.03 parts

Example 4
A thermal transfer image receiving sheet of Example 4 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 4>
2.50 parts urethane-modified copolymer polyester resin (Dainippon Ink & Chemicals, AP40)
Polyethylene wax dispersion 1.0 part (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.64 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemistat 6120, solid content 30.4%, based on polystyrene sulfonate alkali salt)
2.00 parts of cellulose filler (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 19.52 parts

(Example 5)
A thermal transfer image receiving sheet of Example 5 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 5>
1.25 parts of urethane-modified copolyester resin (manufactured by Nikka Chemical Co., Ltd., Neo Sticker 1200)
Polyethylene wax dispersion 0.93 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.52 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemist 6120, solid content 30.4%, polystyrene sulfonate alkali salt as the main component)
Cellulose filler 1.85 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 19.12 parts

(Example 6)
A thermal transfer image receiving sheet of Example 6 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 6>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 2.50 parts Nylon (registered trademark) 12 filler 0.16 parts (polyamide resin filler, MW330, manufactured by Shinto Chemical Co., Ltd.)
1.32 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Ltd., Chemistat 6120, solid content 30.4%, polystyrene sulfonate alkali salt as the main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.76 parts

(Example 7)
A thermal transfer image-receiving sheet of Example 7 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 7>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 2.50 parts Polypropylene wax dispersion (manufactured by Mitsui Chemicals, Chemipearl WP100, average particle size 1 μm) 0.80 parts Anionic polymer 1.32 parts (Sanyo Chemical Industry Co., Ltd., Chemistat 6120, solid content 30.4%, polystyrene sulfonic acid alkali salt as the main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.12 parts

(Example 8)
In the thermal transfer image receiving sheet produced in Example 1, the thermal transfer image receiving sheet of Example 8 was produced in the same manner as in Example 1 except that the back layer had the following composition.
<Back layer coating solution 8>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 2.50 parts Silica fine particles (manufactured by Fuji Silysia, Cicilia 256N, average particle size 3 μm) 0.16 parts Anionic polymer 1.32 parts (Sanyo Chemical Industries ( Co., Ltd., Chemistat 6120, solid content 30.4%, polystyrenesulfonic acid alkali salt as the main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.76 parts

Example 9
A thermal transfer image receiving sheet of Example 9 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 9>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 2.50 parts Zinc stearate filler (manufactured by Chukyo Yushi Co., Ltd., Hydrin L-536) 0.46 parts Anionic polymer 1.32 parts (Sanyo Kasei) Manufactured by Kogyo Co., Ltd., Chemistat 6120, solid content 30.4%, polystyrene sulfonic acid alkali salt as the main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.46 parts

(Example 10)
The thermal transfer image receiving sheet of Example 10 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back layer coating solution 10>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 2.50 parts Polyethylene wax filler 0.80 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.21 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Chemista SA09, solid content 33%, polystyrene sulfonate alkali salt as main component)
Cellulose filler 10.0 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.22 parts

(Example 11)
A thermal transfer image receiving sheet of Example 11 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 11>
2.50 parts of polyvinyl butyral resin (Denka Butyral # 3000-1, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Nylon (registered trademark) 12 filler 0.20 part (polyamide resin filler, MW330, manufactured by Shinto Chemical Co., Ltd.)
Cation-modified acrylic resin (ELECOND PQ-50B, manufactured by Soken Chemical Co., Ltd.) 0.98 parts Cellulose filler 2.00 parts (manufactured by Nippon Paper Chemicals Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Methyl ethyl ketone / ethanol (mass ratio 1: 1) 20.99 parts

Example 12
A thermal transfer image receiving sheet of Example 12 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 12>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 2.50 parts Polyethylene wax filler 0.80 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
Conductive needle crystal (FT-3000, manufactured by Ishihara Sangyo Co., Ltd.) 0.40 parts (average fiber diameter 0.27 μm, average fiber length 5.15 μm, aspect ratio 19.1, crystal base is TiO ₂ , crystal The conductive agent is SnO ₂ / Sb)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 16.03 parts

(Example 13)
A thermal transfer image receiving sheet of Example 13 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 13>
Polyester resin (Toyobo Co., Ltd., Vylonal MD1480) 1.25 parts Polyethylene wax filler 0.93 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
Conductive synthetic layered silicate (Laponite JS, manufactured by Wilbur Ellis) 0.46 parts Cellulose filler 1.85 parts (Nippon Paper Chemicals, Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 20.17 parts

(Example 14)
A thermal transfer image receiving sheet of Example 14 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 was changed to the following composition.
<Back layer coating solution 14>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 2.50 parts Polyethylene wax filler 0.80 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.32 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Chemist SA09, solid content 33%, polystyrene sulfonate alkali salt as main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG06MG, average particle size 6 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 15.12 parts

(Comparative Example 1)
A thermal transfer image receiving sheet of Comparative Example 1 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 16>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 2.50 parts Polyethylene wax filler 0.80 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 13.10 parts

(Comparative Example 2)
A thermal transfer image receiving sheet of Comparative Example 2 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 17>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 2.50 parts Anionic polymer 1.32 parts (Sanyo Chemical Industries, Chemista SA09, solid content 33%, polystyrenesulfonic acid alkali salt Main component)
Cellulose filler 1.60 parts (Nippon Paper Chemical Co., Ltd., Chemipearl WG10MG2, average particle size 10 μm)
Water / isopropyl alcohol (mass ratio 1: 1) 14.58 parts

(Comparative Example 3)
A thermal transfer image-receiving sheet of Comparative Example 3 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 18>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries, Inc., IJC403A) 2.50 parts Polyethylene wax filler 0.80 parts (Mitsui Chemicals, Chemipearl W310, average particle size 10 μm)
1.32 parts of anionic polymer (manufactured by Sanyo Chemical Industries, Chemist SA09, solid content 33%, polystyrene sulfonate alkali salt as main component)
Water / isopropyl alcohol (mass ratio 1: 1) 3.38 parts

(Comparative Example 4)
A thermal transfer image-receiving sheet of Comparative Example 4 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 19>
2.50 parts of polyvinyl butyral resin (Denka Butyral # 3000, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Nylon (registered trademark) 12 filler 0.20 part (polyamide resin filler, MW330, manufactured by Shinto Chemical Co., Ltd.)
Cation-modified acrylic resin (ELECOND PQ-50B, manufactured by Soken Chemical Co., Ltd.) 0.98 parts Water / isopropyl alcohol (mass ratio 1: 1) 6.32 parts

Using the thermal transfer image receiving sheets of Examples 1 to 15 and Comparative Examples 1 to 4 prepared as described above as samples, the following items were tested, and the results are shown in Table 1.
<Writing aptitude>
On the back surface of the thermal transfer image-receiving sheet, letters were handwritten using an oil pen, aqueous pen, pencil, and ballpoint pen, and writing aptitude was evaluated according to the following criteria.
○: Smooth writing with sufficient writing density, no bleeding, and good fixability.
Δ: Written density is slightly light, and bleeding occurs slightly in the writing area. However, there is no practical problem.
X: The characters in the writing part cannot be read by lightly rubbing the writing part with a finger. Or writing is difficult.

<Friction between image receiving sheets>
Using the thermal transfer image-receiving sheets of each of the examples and comparative examples prepared above, after being left for 3 days under a load of 20 kg / cm ² in an environment of 60 ° C. in advance, after storage in each example The 100 thermal transfer image-receiving sheets are placed in the paper feeding section of a Canon photo printer CP710 and combined with the dedicated thermal transfer sheet for the CP710 printer to perform thermal transfer recording. The influence on the image receiving surface due to the rubbing of the image, that is, the presence or absence of image quality defects such as streaks and unevenness in the thermal transfer recording portion (image portion) was examined. Evaluation was performed according to the following criteria.
◯: There is no image quality defect such as streak or unevenness, and it is very good.
Δ: Some image quality defects such as streaks and unevenness occur, but there is no problem.
X: Image quality defects such as streaks and unevenness occur.

<Releasability>
In the dedicated thermal transfer sheet of Canon photo printer CP710, for each color of yellow, magenta, and cyan, the back surfaces of the thermal transfer image receiving sheets of the above examples and comparative examples are overlapped with each dye layer facing each other. Under the conditions, thermal transfer recording was performed using a thermal head, and the releasability, that is, the thermal fusing property between the back surface of the thermal transfer image receiving sheet and the dye layer of the thermal transfer sheet was examined.

(Printing conditions)
-Thermal head: KGT-217-12MPL20 (manufactured by Kyocera)
-Heating element average resistance value: 3195 (Ω)
・ Print density in the main scanning direction; 300 dpi
・ Print density in the sub-scanning direction; 300 dpi
Applied power: 0.12 (w / dot)
・ One line cycle: 5 (msec.)
・ Printing start temperature: 40 (℃)
Gradation control method Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 in one line period with a pulse length obtained by equally dividing one line period into 256, the duty of each divided pulse The ratio was fixed at 60%, the number of pulses was 200, and three-color solid printing of yellow, magenta, and cyan was performed.

Evaluation of releasability was performed according to the following criteria.
○: No heat fusion, light peeling and good.
X: It is heat-sealed and is defective.

(Adhesiveness of stamps)
Tap water was applied to the half of the adhesive surface of the Japanese postage stamp, and the above-mentioned stamp was rubbed onto the back surface of each thermal transfer image-receiving sheet prepared in the examples and comparative examples with an index finger. After leaving in a room at 25 ° C. for 5 hours, the part not coated with tap water was held between the thumb and forefinger, the stamp was peeled off from the thermal transfer image-receiving sheet, and evaluated according to the following criteria.
○: After the stamp is peeled off, a part of the stamp remains on the back surface of the thermal transfer image-receiving sheet, and a trace remains.
X: The stamp is easily peeled off from the back surface of the thermal transfer image receiving sheet, no stamp remains on the back surface of the thermal transfer image receiving sheet, and no trace remains.

(Antistatic property)
In each of the thermal transfer image receiving sheets of Examples and Comparative Examples, 50 thermal transfer image receiving sheets of each example (for example, the thermal transfer image receiving sheets of Example 1 in Example 1) are stacked in an environment of 25 ° C. and 30% RH. Using the thermal transfer sheet for Canon photo printer CP710, the receiving layers of the thermal transfer image receiving sheets of the above-mentioned examples and comparative examples and the dye layer of the thermal transfer sheet are opposed to each other, and the yellow and magenta are printed with Canon photo printer CP710. Then, 50 image-receiving sheets were continuously printed under the conditions of printing in cyan order to form a full-color image. As the antistatic property of the thermal transfer image-receiving sheet in the printing, the antistatic property was evaluated by checking the presence or absence of two sheets or printing misalignment (1 mm or more). The judgment criteria are as follows.
○: Two out of 50 sheets are not inserted and no printing misalignment occurs.
X: More than 10 out of 50 sheets, two sheets were inserted, and printing misalignment occurred.

The evaluation results of the above tests are shown in Table 1 below.

Claims (2)

  In a thermal transfer image-receiving sheet in which a dye-receiving layer is formed on at least one surface of a substrate sheet, a thermoplastic resin, a cellulose filler, and an antistatic material are formed on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed. A thermal transfer image-receiving sheet, wherein a back layer containing an agent and a slip agent is formed. 2. The thermal transfer image receiving sheet according to claim 1, wherein a back surface intermediate layer is formed between the base material sheet and the back surface layer.