JP5181974B2 - Thermal transfer sheet - Google Patents

Description

  The present invention relates to a thermal transfer sheet, and more particularly, in a thermal transfer sheet in which a heat transferable color material layer is formed on one surface of a base film and a heat resistant slipping layer is formed on the other surface. No long-term heat treatment (aging) to form a layered cured film, no problem of dye kickback, and sufficient suppression of print residue during thermal transfer, high quality without color loss The present invention relates to a thermal transfer sheet from which a printed product can be obtained.

  Conventionally, as a thermal transfer sheet, a sublimation in which a plastic film such as a polyester film is used as a base film, and a dye layer which is a thermal transfer color material layer made of a sublimation dye and a binder resin is provided on one surface of the base film. There are two types of thermal transfer sheets: a thermal transfer sheet and a thermal melting type thermal transfer sheet provided with a thermal melting color material layer made of a thermal melting composition containing a colorant instead of the dye layer. These thermal transfer sheets are heated in the form of an image from the back by a thermal head, and a dye layer or a heat-meltable ink layer is transferred to a transfer material to form an image.

  Furthermore, in the case of conventional thermal transfer sheets, when a high temperature above the melting point of plastic is applied to the plastic film of the base film from the thermal head, the plastic film adheres (sticks) to the thermal head, causing residue to adhere. There are problems that the peelability and slipping property are impaired and the base film is torn. For this reason, a method of forming a heat-resistant layer made of a thermosetting resin having high heat resistance has been proposed. Although this method improves the heat resistance, the slip property of the thermal head is not improved. Furthermore, since the base material is a plastic thin film that cannot be treated at high temperature, long-term heat treatment (aging) for several tens of hours at a relatively low temperature is required after coating in order to obtain a sufficient cured film. This is not only troublesome in the process, but if strict temperature control is not performed, wrinkles are generated during heat treatment, or the opposite surface that contacts the coated surface is bonded and blocked. is there.

  In order to improve the slip property, it has been proposed to add a lubricant such as silicone oil, low melting point WAX, metal soap, surfactant, etc. to the heat-resistant layer to form a heat-resistant slip layer. When the above lubricant is used, there is a problem that when the thermal transfer sheet is wound up, it moves to the opposite surface or the thermal head is contaminated during printing. In addition, there is a method of adding a filler to remove these deposits, but if an inappropriate material is used, the coefficient of friction with the thermal head increases, causing wrinkles during printing, There is a problem of wearing.

  In addition, the thermal transfer sheet provided with the heat resistant slipping layer on the back surface of the base film has a heat resistance from the colorant layer due to the contact between the colorant layer and the heat resistant slipping layer when stored in a wound state after manufacture. There was a problem of dye transfer (kick) to the slipping layer. The dye transferred to the heat-resistant slipping layer is rolled back to re-transfer to another color material layer, protective layer, etc. (back), and the contaminated layer is thermally transferred to the image receiving sheet. There is also a problem that the printing accuracy is remarkably deteriorated due to a hue different from the color designated by. This is the problem of kickback. In addition, due to long-term contact between the heat-resistant slipping layer and the color material layer, the dye bleeds on the surface of the color material layer, resulting in background stains in which the unprinted area (the area without heating from the thermal head) is colored. was there.

  On the other hand, with the recent increase in speed of printers, it is required to increase the thermal energy of the thermal head, increase the sensitivity of the thermal transfer sheet, increase the dye content in the color material layer, etc. This increases the possibility of dye transfer to the heat resistant slipping layer and the occurrence of problems during thermal transfer due to this transfer. For this reason, the demand for a heat-resistant slipping layer having good kickback prevention performance is increasing.

  As a thermal transfer sheet with improved kickback prevention performance, for example, Patent Document 1 discloses that the Tg of a polyvinyl acetal resin used for a heat resistant slipping layer is 80 ° C. or higher and the melting point of a phosphate ester used as a lubricant. A thermal transfer sheet that is limited to 35 ° C. or more and suppresses retransfer (back) of the dye is proposed, and Patent Document 2 limits the roughness (SRz) of the heat-resistant slipping layer to 3.0 μm or more. It has been proposed that a thermal transfer sheet having a dye layer and a laminate layer provided on the other surface of the substrate to suppress coloring (back) to the laminate layer. Patent Document 3 discloses a heat-resistant resin, a lubricant having a melting point of 33 ° C. or higher and an IO value (a value that produces organic / inorganic properties from an organic conceptual diagram) of 0.23 or higher, A thermal transfer sheet with a heat-resistant slip layer formed from a mixture of polyisocyanate compounds having two or more isocyanate groups. It has been proposed that there is little retransfer of dyes, no blocking, and no thermal wrinkles. ing.

  However, in the recent thermal transfer recording system using a thermal transfer sheet, the thermal energy of the thermal head is steadily increasing in order to increase the printing speed and to output a clearer image at a higher density. As the thermal energy of the thermal head increases, head residue (hereinafter also referred to as “print residue”) is collected by scraping the heat-resistant resin of the back layer to the thermal head portion during thermal transfer. There has been a problem that dyes or the like are not transferred, and color loss or color unevenness occurs in the obtained printed matter. In particular, there is a problem in which the occurrence of such a print residue is noticeable in the thermal transfer sheet that improves the kickback performance as described above.

JP-A-9-300827 JP 2000-225775 A JP 2002-11967 A

  Therefore, in order to solve the above problems, the object of the present invention is to provide a thermal transfer sheet in which a heat transferable color material layer is formed on one surface of a base film and a heat resistant slipping layer is formed on the other surface. No long-term heat treatment to form a cured film of the heat-resistant slipping layer, no problem of dye kickback, sufficient suppression of print residue during thermal transfer, and high quality without color loss It is an object of the present invention to provide a thermal transfer sheet capable of obtaining a printed product.

  The above object is achieved by the present invention described below. That is, the present invention relates to a thermal transfer sheet having a heat transferable color material layer on one surface of a base film and a heat resistant slip layer formed on the other surface of the base film. Contains 5 to 10% of polyvinyl butyral and polyisocyanate in a proportion of 2.5 to 7 parts by mass of polyisocyanate with respect to 10 parts by mass of polyvinyl butyral and phosphate ester-based surfactant based on the total solid content. It is characterized by comprising a cured product of the composition for heat-resistant slipping layer containing 3 to 5% of a reactive silicone oil based on the total solid content.

The phosphate-based surfactant in the composition for heat resistant slipping layer is contained in a proportion of 5 to 10% based on the total solid content, and the reactive silicone oil is contained in a proportion of 3 to 5% based on the total solid content. By containing, the problem of dye kickback is prevented, and the slipperiness with the thermal head is improved. In the thermal transfer sheet of the present invention, the heat resistant slipping layer preferably contains a metal soap and further a filler. The metal soap makes the slipping property with the thermal head more stable, and the filler improves the cleaning property and slipping property of the residue adhering to the thermal head, and is also effective for preventing blocking in winding.
Further, in the thermal transfer sheet of the present invention, the reactive silicone oil is any one of one-end phenol group-modified silicone oil, one-end epoxy group-modified silicone oil, one-end diol group-modified silicone oil, and one-end carbinol group-modified silicone oil. It is preferable that

  In the thermal transfer sheet of the present invention described above, the heat resistant slipping layer contains polyvinyl butyral and polyisocyanate in a proportion of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and as a lubricant. A composition comprising a cured product of a composition for a heat-resistant slipping layer containing 5 to 10% of a phosphate ester surfactant based on the total solid content and 3 to 5% of a reactive silicone oil based on the total solid content. did. That is, with respect to the composition of the heat-resistant slipping layer, the polyisocyanate to be reacted and cured is contained in the above range with respect to polyvinyl butyral, and the composition for the heat-resistant slipping layer is not subjected to long-term heat treatment (aging). The heat-resistant slipping layer could be completely cured only by the coating and drying process of forming the heat-resistant slipping layer. The composition of the heat resistant slipping layer is used for reducing the content of polyisocyanate, and for reducing the amount of the phosphate phosphate surfactant and the content of the lubricant within the above range. A reactive silicone oil is added.

  By using the above-described thermal transfer sheet of the present invention, there is no problem of long-term heat treatment (aging) for forming a cured film of the heat-resistant slipping layer, no problem of dye kickback, and generation of print residue during thermal transfer Can be sufficiently suppressed, and a high-quality printed product without color loss can be formed.

Next, an embodiment of the invention will be described in detail.
FIG. 1 shows one embodiment which is a thermal transfer sheet of the present invention. The heat transferable color material layer 3 is provided on one surface of the base film 1, and the heat resistant slipping layer 2 is formed on the other surface of the base film 1. FIG. 2 shows another embodiment which is a thermal transfer sheet of the present invention. A yellow color material layer 31, a magenta color material layer 32, and a cyan color material layer 33 are repeatedly provided on one surface of the base film 1 as the heat transferable color material layer 3 in the surface order, and the other surface of the base film 1. In addition, the heat-resistant slip layer 2 is formed.
Below, each layer which comprises the thermal transfer sheet of this invention is demonstrated in detail.

(Base film)
The base film 1 constituting the thermal transfer sheet of the present invention may be any one as long as it has a conventionally known degree of heat resistance and strength, for example, 0.5 to 50 μm, preferably 1.5 to Polyethylene terephthalate film having a thickness of about 10 μm, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, Cellulose, cellulose derivatives such as cellulose acetate, resin films such as polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film In addition, paper such as condenser paper and paraffin paper, nonwoven fabric, or a composite of paper or nonwoven fabric and resin may be used.

  The base film 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, grafting treatment, etc. should be applied. Can do. Only one type of surface treatment may be performed, or two or more types may be performed. In the present invention, among the surface treatments described above, corona treatment or plasma treatment is preferable because of its low cost. Moreover, you may form an undercoat layer (primer layer) in the one surface or both surfaces as needed.

(Heat resistant slipping layer)
The heat resistant slip layer 2 is formed for the purpose of improving the running performance, heat resistance, etc. of the thermal head during printing. In the present invention, the heat-resistant slipping layer is composed of a cured product of a composition for heat-resistant slipping layer containing polyvinyl butyral and polyisocyanate, a phosphate ester surfactant, and a reactive silicone oil. Polyvinyl butyral which reacts with polyisocyanate to form a binder resin contains —OH groups, which are reactive groups with polyisocyanate, in an appropriate ratio. Among the above compounds, molecular weight is particularly 60,000 to 200. Polyvinyl butyral having a glass transition temperature of 60 to 110 ° C. and a vinyl alcohol part content of 15 to 40% is preferable. When the mass of the vinyl alcohol part contained is less than 15%, the crosslinking density of the binder of the heat resistant slipping layer is low, and the heat resistance is lowered. On the other hand, if the mass of the vinyl alcohol part contained exceeds 40%, the crosslinking density of the heat resistant slipping layer is too high, and a large amount of polyisocyanate is required. Long-term heat treatment (aging) is required.

  The polyisocyanate and the polyvinyl butyral are reacted and cured by heating or the like to form a cured product that is a resin having excellent heat resistance and mechanical strength. This hardened | cured material can improve the heat resistance of a heat resistant slipping layer, coating-film intensity | strength, and adhesiveness with a base film. The polyisocyanate used in the present invention may be a polyisocyanate conventionally used for the synthesis of paints, adhesives or polyurethanes.

  As the polyisocyanate, various kinds of polyisocyanate have been conventionally known. Of these, it is desirable to use an adduct of an aromatic isocyanate. As the aromatic polyisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, Examples include p-phenylene diisocyanate, trans-cyclohexane, 1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatephenyl) thiophosphate, especially 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Or, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferable.

  The addition amount of polyisocyanate is in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral which is a binder resin constituting the heat resistant slipping layer. When the amount of polyisocyanate used is insufficient, the heat resistance is insufficient because the crosslinking density is low. On the other hand, if the amount is too large, the shrinkage of the formed coating film cannot be controlled, and the curing time is prolonged, unreacted- NCO groups remain in the slipping layer, causing problems such as reaction with moisture in the atmosphere.

As a slipperiness imparting agent (lubricant) to be added to the heat resistant slipping layer to improve the slipperiness, a phosphate ester surfactant that can provide sufficient slipperiness when heated by a thermal head (during printing) Add. As the phosphate ester surfactant,
1) A long-chain alkyl phosphate ester, for example, a saturated or unsaturated higher alcohol having 6 to 20 carbon atoms, preferably 12 to 18 carbon atoms, such as cetyl alcohol, stearyl alcohol, oleyl alcohol, etc. and phosphoric acid Mono and / or diester, etc.
2) Phosphate esters such as polyoxyalkylene alkyl ether or polyoxyalkylene alkyl aryl ether,
3) Alkylphenol or alkylnaphthol (nonylphenol) having at least one, preferably 1-2 alkyl groups having an alkylene oxide adduct (usually 1 to 8 addition moles) or 8 to 12 carbon atoms of the saturated or unsaturated alcohol. Nonionic or anionic phosphate ester surfactants such as phosphate mono- or diester salts of dodecylphenol and diphenylphenol).

  The amount of the phosphate ester surfactant used is 5% to 10% with respect to the total solid content of the heat resistant slipping layer. If the amount of phosphate ester surfactant added is small, the thermal releasability to the thermal head will not be sufficient, causing print defects, head defects, and sticking. When the thermal transfer sheet is wound and stored, the dye of the thermal transfer colorant layer facing the heat transfer layer is transferred to the heat resistant slipping layer, or the phosphate ester surfactant of the heat resistant slipping layer is used. It may shift to the heat transferable color material layer excessively and affect the color reproducibility of the printed matter.

  The heat resistant slipping layer in the thermal transfer sheet of the present invention contains a reactive silicone oil. The reactive silicone oil is a silicone oil having a functional group, and is blended for the purpose of reducing surface friction and preventing sticking. In general, known reactive silicone oils can be used. Examples thereof include alcohol-modified, amino-modified, epoxy-modified, methacryl-modified, mercapto-modified, phenol-modified, diol-modified, carbinol-modified silicone oil. Also, depending on the position of the functional group, there are a side chain (modified) type, a both terminal (modified) type, a single terminal (modified) type, etc. In the present invention, it is possible to use a silicone oil having these functional groups. it can. A double-ended type or a single-ended type is preferred.

  The reactive silicone oil is contained in an amount of 3% to 5% with respect to the total solid content of the heat resistant slipping layer. If the amount of silicone oil added is small, it will not be possible to obtain releasability from the thermal head, and it will be easy to fuse with the thermal head. On the other hand, if the amount of silicone oil added is too large, dye transferability increases, causing the problem of kickback, or the silicone oil adheres to the thermal head during printing and causes the problem of contamination.

  The heat-resistant slipping layer contains a phosphate ester surfactant and reactive silicone oil to provide lubricity at the time of printing and non-printing, but to improve the cleanability to the thermal head. In order to improve the kickback prevention performance, an inorganic or organic filler can be added. Examples of the inorganic filler include clay minerals such as talc and kaolin, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as aluminum hydroxide and magnesium hydroxide, sulfates such as calcium sulfate, and oxides such as silica. Inorganic fillers such as graphite, nitrate and boron nitride. Examples of organic fillers include acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, polystyrene resin, nylon resin, etc., or a crosslinked resin obtained by reacting these with a crosslinking agent. A filler etc. are mentioned.

  Any of the above inorganic or organic fillers preferably has an average particle size of about 0.5 to 5.0 μm. Moreover, said inorganic or organic filler has a preferable content rate of 3%-6% with respect to the total solid of a heat-resistant slipping layer. If the amount of the filler added is too small, the cleaning property is insufficient, while if too large, the flexibility and film strength of the heat-resistant slip layer formed are lowered.

  Examples of the metal soap include polyvalent metal salts of alkyl phosphates and metal salts of alkyl carboxylic acids. As the polyvalent metal salt of the alkyl phosphate, those known as additives for plastics can be used. The polyvalent metal salt of the alkyl phosphate ester is generally obtained by substituting the alkali metal salt of the alkyl phosphate ester with a polyvalent metal, and various grades are available. The alkyl group in the alkyl phosphate ester preferably has 12 or more carbon atoms, and a stearyl group is particularly preferred because of its excellent lubricity. Further, the metal salt in the polyvalent metal salt of alkyl phosphate is preferably zinc or aluminum salt. In addition, regarding the metal salt of the alkyl carboxylic acid of the above metal soap, the alkyl group preferably has 11 or more carbon atoms, particularly preferably a dodecyl group or a heptadecyl group, and as the metal salt, magnesium salt, zinc salt, aluminum salt Is preferred. The metal soap may be added in order to further stabilize the slidability of the thermal head and the heat resistant slipping layer.

  In order to provide the heat resistant slipping layer on the base film, the above components are dissolved in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene, etc., and the composition for heat resistant slipping layer (ink or coating liquid) is obtained. Is prepared and formed on the substrate film by a conventional appropriate printing method such as gravure coater, roll coater, wire bar, and coating method. Next, drying is performed by heating to a temperature of 30 ° C. to 80 ° C., and a resin having a hydroxyl group that is an active hydrogen group is reacted and cured with polyisocyanate to form a heat-resistant slipping layer.

The thickness of the heat-resistant slip layer is a coating weight of ^{solids, 0.5g / m 2 ~5.0g / m} 2, and preferably from ^{1.0g / m 2 ~2.0g / m 2} . When this film thickness is less than 0.5 g / m ² , the effect as a heat-resistant slip layer is not sufficient, and when it is thicker than 5.0 g / m ² , the thermal head to the heat transferable color material layer Heat transfer becomes worse, and the printing density is lowered. When a heat resistant slipping layer is provided on the base film, it is preferable to heat in order to promote the reaction between the binder resin and the polyisocyanate, but in order not to affect the heat transferable color material layer. In addition, it is preferable to provide a heat transferable color material layer after the heat resistant slipping layer is provided on the base sheet.

(Heat transferable color material layer)
When the heat transferable color material layer 3 formed on the other surface of the base film provided with the heat resistant slipping layer is a sublimation type heat transfer sheet, it forms a layer containing a sublimation dye, In the case of a melt-type thermal transfer sheet, the layer is formed with a hot-melt ink colored with a pigment or the like. Hereinafter, although a sublimation type thermal transfer sheet will be described in detail as a representative example, the present invention is not limited to only a sublimation type thermal transfer sheet.

  As the dye used in the sublimation type heat transferable color material layer, any dye conventionally used in known heat transfer sheets can be used in the present invention and is not particularly limited. These dyes include methines such as diarylmethane, triarylmethane, thiazole and merocyanine, indoaniline, azomethine such as acetophenone azomethine, pyrazoloazomethine, imidazole azomethine and pyridone azomethine, xanthene and oxazine. Cyanomethylene, thiazine, azine, acridine, benzeneazo, and pyridoneazo, thiophenazo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo represented by dicyanostyrene and tricyanostyrene Azo, such as, disazo, spiropyran, indolinospiropyran, fluoran, rhodamine lactam, naphthoquinone, anthraquinone, quinophthalone It is. Specifically, the following dyes are used.

C. I. (Color Index) Disperse Yellow 51, 3, 54, 79, 60, 23, 7, 141, 201, 231
C. I. Disperse Blue 24, 56, 14, 301, 334, 165, 19, 72, 87, 287, 154, 26, 354
C. I. Disperse thread 135, 146, 59, 1, 73, 60, 167
C. I. Disperse Orange 149
C. I. Disperse violet 4, 13, 26, 36, 56, 31
C. I. Solvent Yellow 56, 14, 16, 29
C. I. Solvent Blue 70, 35, 63, 36, 50, 49, 111, 105, 97, 11
C. I. Solvent Red 135, 81, 18, 25, 19, 23, 24, 143, 146, 182
C. I. Solvent Violet 13
C. I. Solvent Black 3
C. I. Solvent Green 3

  For example, Foron brilliant yellow S-6GL (Sand, Disperse Yellow 231), Macrolex Yellow 6G (Bayer, Disperse Yellow 201) as a yellow dye, and MS-RED-G (Mitsui Toatsu Chemical Co., Ltd.) as a magenta dye Company, Disper Thread 60), Macrolex Red Violet R (manufactured by Bayer, Dispers Violet 26), cyan dye is Kayaset Blue 714 (Nippon Kayaku Co., Ltd., Solvent Blue 63), Foron Brilliant Blue S-R (Sand, Disperse Blue 354), Waxoline Blue AP-FW (ICI, Solvent Blue 36) and the like.

  Next, as a binder resin for carrying the above dye, cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, acetic acid / butyric acid cellulose, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl Examples include vinyl resins such as acetoacetal and polyvinylpyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, and polyester resins. Among these, cellulose , Polyurethane-based, vinyl-based, acrylic-based and polyester-based resins are preferably used in terms of heat resistance, dye transferability and the like.

The dye layer, which is a sublimation-type heat transferable color material layer, adds these dyes and a binder resin, and additives (for example, release agents, etc.), fillers, etc., if necessary, to one surface of the base film. And dissolved in an appropriate organic solvent such as toluene, methyl ethyl ketone, ethanol, isopropyl alcohol, cyclohexanone, DMF, or dispersed in an organic solvent or water, for example, gravure printing, screen printing, reverse roll coating printing A coating film can be formed by coating and drying by means such as a method. Dye layer formed in this way, in the coating amount in thickness, in the dry state, 0.2~5.0g / m ² preferably has a thickness of about 0.4 to 2.0 g / m ² The sublimable dye in the dye layer should be present in an amount of 5 to 90% by mass, preferably 10 to 70% by mass, based on the mass of the dye layer. If the image of the desired heat transferable color material layer is monocolor, it is formed by selecting one of the dye layers such as yellow, magenta, and cyan. If the image is a full color image, suitable yellow, magenta , And cyan (add black if necessary) to form each dye layer.

  The above-described heat transferable color material layer can be provided with a color material layer having a single hue on a base film to form a monocolor print, but at least two or more different hues can be formed. It is preferable to form the heat transferable color material layer on the base film in the surface order. Form two or more dye layers using sublimation dye, combination of dye layer and heat transferable color material layer of heat-meltable ink, or more than two heat-transferable color material layers of heat-meltable ink. May be. In the present invention, in particular, a yellow dye layer, a magenta dye layer, and a cyan dye layer are formed in the surface order as a heat transferable color material layer containing a sublimation dye on a base film, and high quality heat transfer comparable to a full color photographic image. It is preferable to form an image. In the case of a black character or pattern thermal transfer image, it is possible to obtain black by overlaying the above three colors of the yellow color material layer, magenta color material layer, and cyan color material layer of the dye layer. It is preferable to add a color material layer made of black heat-meltable ink using a black colorant to the base film. As a result, a clear image having a high black density can be obtained.

  In addition, the thermal transfer sheet of the present invention may be a transfer protective layer, provided that a heat transferable color material layer is provided on one side of the base film and a heat resistant slipping layer is provided on the other side of the base film. An undercoat layer or other layers may be provided. When the transfer protective layer is formed surface-sequentially with the above-described heat transferable color material layer, the protective layer protecting the image surface can be transferred after image formation, which is useful. The layer configuration and composition of the transfer protective layer are not particularly limited, and can be selected from conventionally known techniques depending on the characteristics of the base film, the heat transferable color material layer, and the like to be used. In addition, the undercoat layer considers the adhesion between the base film and the dye layer or the base film and the heat-resistant slip layer, and particularly improves the transfer efficiency of the dye when provided between the dye layer and the base film. The composition and the like can be appropriately selected from conventionally known techniques.

  The thermal transfer sheet of the present invention has not only very little color transfer (back) to the protective layer and the like due to retransfer of the dye, but also less dye transfer (kick) to the heat-resistant slipping layer, and color reproducibility. It is excellent, and even when used after storage, the hue can be suitably reproduced even in a low density region. The binder resin of the heat-resistant slipping layer of the present invention is a resin obtained by curing polyvinyl butyral with polyisocyanate. In the composition of the heat-resistant slipping layer, the polyisocyanate to be reaction-cured with respect to polyvinyl butyral is polyvinyl butyral. Long-term heat treatment (aging) is performed by containing 2.5 to 7 parts by mass with respect to 10 parts by mass, that is, by reducing the amount of polyisocyanate added to polyvinyl butyral to a minimum. In addition, it became possible to complete the curing of the heat-resistant slipping layer only by applying the composition for heat-resistant slipping layer and forming the heat-resistant slipping layer, which is a drying process. The heat-resistant slipping layer can be efficiently formed on the base film without going through the aging process off-line after the winding having the heat-resistant slipping layer formed thereon.

  Further, the thermal transfer sheet of the present invention is a cured product of the composition for heat resistant slipping layer constituting the heat resistant slipping layer, and the phosphate ester surfactant for improving the slipperiness is 10% with respect to the total solid content. By suppressing the addition amount in the following range, the kickback amount, which is the retransfer of the dye, was suppressed. However, although the amount of the phosphate ester surfactant added is small, the slipping property is lowered, but in order to supplement the slipping property, the reactive silicone oil is added to the total solid content of the heat resistant slipping layer by 5%. It was contained in the following. In this way, by optimizing the content ratio of the material for the heat-resistant slip layer composition constituting the heat-resistant slip layer, the heat-resistant slip layer that is a cured film can be obtained without performing long-term heat treatment (aging). It can be formed efficiently and the problem of dye kickback can be prevented, and a heat-resistant slip layer with excellent heat resistance and slip properties can be formed. As a result, the generation of print residue during thermal transfer can be sufficiently suppressed. Thus, it has become possible to form a high-quality print without color loss.

  In the thermal transfer sheet of the present invention, a predetermined portion is heated and pressed by a thermal head or the like on the heat-resistant slipping layer side of the above-described base film, and a coloring material such as a dye in a portion corresponding to a printing portion in the thermal transferable coloring material layer Can be transferred to a transfer material and printed. When the thermal transfer sheet of the present invention is a thermal sublimation thermal transfer sheet, a thermal transfer image receiving sheet or the like can be used as the transfer material. The thermal transfer image-receiving sheet is not particularly limited as long as the recording surface has dye acceptability. For example, a dye-receiving layer is formed on at least one surface of a substrate such as paper, metal, glass, or synthetic resin. Things can be mentioned. When the thermal transfer sheet is a heat-melting type thermal transfer sheet, ordinary paper, plastic film, or the like can be used as a material to be transferred. The printer used for performing the thermal transfer is not particularly limited, and a known thermal transfer printer can be used.

Next, the present invention will be described more specifically with reference to examples. Hereinafter, unless otherwise specified, parts or% is based on mass.
Example 1
The following composition 1 for heat-resistant slipping layer is applied to one surface of a base film of a polyethylene terephthalate film (Diafoil K203E, manufactured by Mitsubishi Polyester Film Co., Ltd.) having a thickness of 6 μm and subjected to easy adhesion treatment using a wire bar coater. Was applied at a rate of 0.5 g / m ^{2 in} terms of solid content and dried in an oven at 100 ° C. for 1 minute to form a heat resistant slipping layer.

<Composition 1 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 69.6 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 38.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

Apply the following composition for the cyan dye layer (C) to the other surface of the above-mentioned base film (to the easy adhesion treatment surface) with a gravure coater so that the dry coating amount is 0.8 g / m ^2. And dried to form a cyan dye layer, which is a heat transferable color material layer, to produce a heat transfer sheet of Example 1.

<Composition for cyan dye layer (C)>
・ C. I. Solvent Blue 63 3.0 parts / Polyvinyl butyral resin 3.0 parts (BX-1, Sekisui Chemical Co., Ltd.)
・ Methyl ethyl ketone 41.0 parts ・ Toluene 41.0 parts

(Example 2)
A thermal transfer sheet of Example 2 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 2 for heat resistant slipping layer described below.
<Composition 2 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 50.7 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 75.1 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ 7.5 parts of phosphate ester surfactant (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 6.7 mass parts of polyisocyanate with respect to 10 mass parts of polyvinyl butyral.

(Example 3)
A thermal transfer sheet of Example 3 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 3 for heat resistant slipping layer described below.
<Composition 3 for heat resistant slipping layer>
-65.6 parts of polyvinyl polyvinyl butyral (SREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
Polyisocyanate 36.4 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
-Phosphate-based surfactant 10.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

Example 4
A thermal transfer sheet of Example 4 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 4 for heat resistant slipping layer described below.
<Composition 4 for heat resistant slipping layer>
-Polyvinyl polyvinyl butyral 68.0 parts (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
Polyisocyanate 37.8 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-Reactive silicone oil 5.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Example 5)
A thermal transfer sheet of Example 5 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 5 for heat resistant slipping layer described below.
<Composition 5 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 69.6 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 38.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-173DX, manufactured by Shin-Etsu Chemical Co., Ltd., one-end epoxy group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Example 6)
A thermal transfer sheet of Example 6 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 6 for heat resistant slipping layer described below.
<Composition 6 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 69.6 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 38.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-176DX, manufactured by Shin-Etsu Chemical Co., Ltd., one-end diol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Example 7)
A thermal transfer sheet of Example 7 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 7 for heat resistant slipping layer described below.
<Composition 7 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 69.6 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 38.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-Reactive silicone oil 3.0 parts (X-22-160AS, manufactured by Shin-Etsu Chemical Co., Ltd., one-end carbinol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 1)
A thermal transfer sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 8 for heat resistant slipping layer described below.
<Heat resistant slipping layer composition 8>
・ Polyvinylpolyvinyl butyral 78.3 parts (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
-Polyisocyanate 19.3 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 1.1 mass parts of polyisocyanate with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 2)
A thermal transfer sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 9 for heat resistant slipping layer described below.
<Composition 9 for heat resistant slipping layer>
・ 43.5 parts of polyvinyl polyvinyl butyral (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
Polyisocyanate 96.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Reactive silicone oil 3.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 10 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 3)
A thermal transfer sheet of Comparative Example 3 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 10 for heat resistant slipping layer described below.
<Composition 10 for heat resistant slipping layer>
・ 68.8 parts of polyvinyl polyvinyl butyral (SREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
-Polyisocyanate 38.2 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 4.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-Reactive silicone oil 5.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 4)
A thermal transfer sheet of Comparative Example 4 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 11 for heat resistant slipping layer described below.
<Composition 11 for heat resistant slipping layer>
-62.4 parts of polyvinyl polyvinyl butyral (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
Polyisocyanate 34.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 12.0 parts (Plysurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-Reactive silicone oil 5.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 5)
A thermal transfer sheet of Comparative Example 5 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 12 for heat resistant slipping layer described below.
<Composition 12 for heat resistant slipping layer>
-Polyvinyl polyvinyl butyral 66.4 parts (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
-Polyisocyanate 36.9 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
-Phosphate-based surfactant 10.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-Reactive silicone oil 2.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 6)
A thermal transfer sheet of Comparative Example 6 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 13 for heat resistant slipping layer described below.
<Composition 13 for heat resistant slipping layer>
-Polyvinyl polyvinyl butyral 63.2 parts (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
-Polyisocyanate 35.1 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
-Phosphate-based surfactant 10.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
Reactive silicone oil 6.0 parts (X-22-1821, manufactured by Shin-Etsu Chemical Co., Ltd., one-end phenol group-modified silicone oil)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

(Comparative Example 7)
A thermal transfer sheet of Comparative Example 7 was produced in the same manner as in Example 1 except that the composition 1 for heat resistant slipping layer in Example 1 was changed to the composition 14 for heat resistant slipping layer described below.
<Composition 14 for heat resistant slipping layer>
・ Polyvinylpolyvinyl butyral 69.6 parts (ESREC BX-1, Sekisui Chemical Co., Ltd.)
Polyisocyanate 38.7 parts (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 5.0 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
-3.0 parts of dimethyl silicone oil (KF965-100, manufactured by Shin-Etsu Chemical Co., Ltd.)
-Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.0 part-Talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 4.0 parts-Methyl ethyl ketone 100.0 parts -Toluene 100.0 parts The ratio with respect to polyvinyl butyral in said polyisocyanate is 2.5 mass parts of polyisocyanates with respect to 10 mass parts of polyvinyl butyral.

The thermal transfer sheets of each of the above Examples and Comparative Examples were evaluated for kickback prevention, slipperiness of the heat resistant slipping layer, and printing wrinkles. The evaluation method will be described below.
Evaluation method (prevention of kickback)
The heat-resistant slippery layer surface that has been cut into a size of 5 cm × 5 cm and the dye-transferred surface and the protective layer surface are superimposed, and a load of 20 kgf / cm ² is applied using a constant load compression tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) The dye is forcibly retransferred in an environment of 60 ° C. and humidity 20% RH (transition time: 24 hours). However, the protective layer used was the protective layer portion of Canon Inc. color ink / paper set KP-36IP (trade name). However, conditions for dye transfer to the heat-resistant lubricating layer is a thermal transfer sheet of Examples and Comparative Examples described above, superposed heat-resistant lubricating layer surface and the dye layer surface, similar to the loading conditions of the above, the 20 kgf / cm ² The dye was forcibly transferred by leaving it to stand under an environment of 60 ° C. and humidity 20% RH for 24 hours.

  The protective layer surface to which the dye was retransferred and the image receiving surface of the image receiving paper were superposed, and transfer was performed at 105 ° C. and 4 mm · sec / line using a laminating tester (Lamipacker LPD2305PRO, manufactured by Fuji Plastics). Further, the protective layer was peeled off from the image receiving paper, and the hue of the transfer part was measured using GRETAG Spectrolino (D65 light source, viewing angle 2 °; manufactured by Gretag) in accordance with JIS Z 8722 condition a. As the image receiving paper, Canon Inc. color ink / paper set KP-36IP (trade name) was used.

(Evaluation criteria)
(Circle): Color difference (DELTA) E * ab of the transfer material of the protective layer to which dye was retransferred, and the transfer material of the protective layer which was not dye-transferred is less than 1.5.
X: The color difference ΔE * ab between the transfer product of the protective layer to which the dye has been retransferred and the transfer product of the protective layer to which the dye has not been transferred is 1.5 or more.

(Slippery)
Using a thermal head KST-105-13FAN manufactured by Kyocera Corporation, solid (tone value 255/255: density max) and white portion (tone value 0 / tone) with a load of 4 kgW and printing energy 0.10 W / dot 255) was printed at a printing pressure of 30 N, and the dynamic friction force between the thermal head and the heat-resistant slipping layer was measured. The friction coefficient was obtained by dividing the dynamic friction force by the printing pressure.
As the image receiving paper, Canon Inc. color ink / paper set KP-36IP (trade name) was used, and the width of the image receiving paper was 7 cm.

(Evaluation criteria)
The ratio of the friction coefficient (μ255) in the solid printing portion and the friction coefficient (μ0) in the white printing was evaluated for μ255 / μ0 based on the following criteria.
○: 0.7 ≦ μ255 / μ0 ≦ 1.2
X: μ255 / μ0> 1.2 or μ255 / μ0 <0.7
Δ: The ratio of the friction coefficient is in the range of “◯” described above, but print residue adheres to the thermal head.

(Print wrinkles)
Using a thermal head KST-105-13FAN manufactured by Kyocera Corporation, a solid (tone value 255/255: density max.) Is printed at a printing pressure of 30 N with a load of 4 kgW and a printing energy of 0.10 W / dot. The number of wrinkles to be counted was counted. However, as the image receiving paper, Canon Inc. color ink / paper set KP-36IP (trade name) was used, and the width of the image receiving paper was 7 cm.

(Evaluation criteria)
The number of wrinkles generated per screen printed was visually confirmed and counted.
○: 0 △: 1 to 5 ×: 6 or more

Table 1 shows the evaluation results of the above-described kickback prevention property, slipperiness and printing wrinkles.

  In the thermal transfer sheet in Example 1, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate ester surfactant is all solid. Containing 5% of the reactive component and 3% of the reactive silicone oil based on the total solid content, the kickback prevention property, the slipping property of the heat resistant slipping layer, and all the print wrinkle evaluation results were good. Moreover, in the thermal transfer sheet in Example 2, the heat-resistant slipping layer contains polyisocyanate close to the upper limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and a phosphate ester surfactant. Contains 7.5% of the total solid content and 3% of the reactive silicone oil based on the total solid content. Excellent evaluation results for kickback prevention, heat-resistant slip layer and printing wrinkles Met.

  In the thermal transfer sheet in Example 3, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate ester surfactant is completely solid. 10% to the upper limit of the specified range, containing 3% of the reactive silicone oil based on the total solid content, and all evaluation results for kickback prevention, heat-resistant slip layer and printing wrinkles It was good. Moreover, in the thermal transfer sheet in Example 4, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and a phosphate ester surfactant is used. Containing 5% of total solids and 5% of reactive silicone oil at the upper limit of the specified range, all evaluations of kickback prevention, heat-resistant slip layer and printing wrinkles The result was good.

  In the thermal transfer sheet of Example 5, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate ester surfactant is all solid. Containing 5% with respect to the content, and changing the kind of reactive silicone oil used in Examples 1 to 4 to include 3% with respect to the total solid content, preventing kickback and heat-resistant slipping layer All the evaluation results of slipperiness and wrinkle of printing were good. Moreover, in the thermal transfer sheet in Example 6, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate ester surfactant is added. Containing 5% of the total solid content and changing the kind of reactive silicone oil used in Examples 1 to 5 to include 3% of the total solid content. All the evaluation results of the slipperiness of the adhesive layer and the print wrinkles were good.

  In the thermal transfer sheet in Example 7, the heat-resistant slipping layer contains polyisocyanate at a lower limit in the range of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate ester surfactant is all solid. Containing 5% with respect to the content, and changing the kind of reactive silicone oil from that used in Examples 1 to 6 to include 3% with respect to the total solid content. All the evaluation results of slipperiness and wrinkle of printing were good.

  In the thermal transfer sheet in Comparative Example 1, the heat-resistant slipping layer contains 1.1 parts by weight of the polyisocyanate with respect to 10 parts by weight of polyvinyl butyral, and is less than the specified range, thus preventing kickback and slipping of the heat-resistant slipping layer. Was good, but the evaluation result of printing wrinkles was poor. Further, in the thermal transfer sheet in Comparative Example 2, the heat-resistant slipping layer contains 10 parts by weight of polyisocyanate with respect to 10 parts by weight of polyvinyl butyral. The evaluation results of slipperiness and printing wrinkles were poor. The thermal transfer sheet in Comparative Example 3 contains 4% of the phosphate ester-based surfactant with respect to the total solid content, and is less than 5 to 10% with respect to the total solid content, which is a preferred range. The evaluation results of the slipperiness of the heat resistant slipping layer and the print wrinkles were poor.

  The thermal transfer sheet in Comparative Example 4 contains 12% of the phosphate ester surfactant based on the total solid content, which is larger than the specified range, and the slip resistance and printing wrinkle of the heat resistant slipping layer are good, but the kickback prevention property is good. It was bad. In the thermal transfer sheet in Comparative Example 5, the heat-resistant slipping layer contains 2% of the reactive silicone oil with respect to the total solid content, and is less than 3 to 5% with respect to the total solid content, which is a preferred range. Although it was good, the sliding property of the heat resistant slipping layer and the evaluation result of the printing wrinkle were poor. The thermal transfer sheet in Comparative Example 6 contains 6% of the reactive silicone oil based on the total solid content, which is larger than the specified range, and the heat-resistant slipping layer has good sliding properties and printing wrinkles, but has poor kickback prevention properties. there were. In the thermal transfer sheet of Comparative Example 7, the heat-resistant slipping layer is not composed of a cured product of a composition containing reactive silicone, and the kickback prevention property is good. The result was bad.

It is sectional drawing which shows one embodiment which is the thermal transfer sheet of this invention. It is sectional drawing which shows other embodiment which is the thermal transfer sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base film 2 Heat resistant slipping layer 3 Thermal transferable color material layer

Claims (4)

  In a thermal transfer sheet having a heat transferable color material layer on one side of a base film and a heat resistant slipping layer formed on the other side of the base film, the heat resistant slipping layer is made of polyvinyl butyral and polyisocyanate. The polyisocyanate is contained in a proportion of 2.5 to 7 parts by mass with respect to 10 parts by mass of polyvinyl butyral, and the phosphate surfactant is contained in an amount of 5 to 10% based on the total solid content. A thermal transfer sheet comprising a cured product of a composition for a heat-resistant slipping layer containing 3 to 5% based on the total solid content.   The thermal transfer sheet according to claim 1, wherein the heat-resistant slipping layer further contains a metal soap.   The thermal transfer sheet according to claim 1, wherein the heat-resistant slipping layer further contains a filler.   The reactive silicone oil is any one of one-end phenol group-modified silicone oil, one-end epoxy group-modified silicone oil, one-end diol group-modified silicone oil, one-end carbinol group-modified silicone oil, The thermal transfer sheet according to claim 1.

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