JP2012006342A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer sheet which forms a heat-resistant slipping layer in an inline process even though it uses a binder resin comprised of hydroxy thermoplastic resin and polyisocyanate such as polyvinyl acetal resin, and which also inhibits a kickback phenomenon.SOLUTION: The thermal transfer sheet includes: a base material; a color material layer formed at one side of the base material; and a heat-resistant slipping layer formed at the other side of the base material with the color material provided thereon. The heat-resistant slipping layer includes a least a binder resin composed of hydroxy thermoplastic resin and polyisocyanate resin, a slipping material, and polyethylene wax. The hydroxyl number of the hydroxy thermoplastic resin is 9 mass% or higher, and a molar ratio (-NCO/-OH) between the isocyanate group of the polyisocyanate resin and the hydroxyl number of the hydroxyl thermoplastic resin is 0.3 to 2.0.

Description

  The present invention relates to a thermal transfer sheet having a color material layer on one side of a substrate and a heat-resistant slipping layer on the other side, and more specifically, without forming one end after forming the heat-resistant slipping layer. The present invention relates to a thermal transfer sheet capable of forming a color material layer in-line.

  Conventionally, various thermal transfer recording methods are known. Among them, methods for forming various full-color images using a thermal transfer sheet in which a color material layer carrying a dye for sublimation transfer with an appropriate binder is provided on a substrate have been proposed. An image formed using such a thermal transfer sheet is very clear and excellent in transparency because the color material used is a dye. It is possible to form a high-quality image that is similar to an image obtained by conventional offset printing or gravure printing and that is comparable to a full-color photographic image.

  When an image is formed using a thermal transfer sheet, generally, a printer having a linear thermal head in which heating elements are arranged in a row is used, and in a direction perpendicular to the length direction of the thermal head, An image is formed by transferring the dye to the transfer material by applying heat from the base material surface side while scanning the color material layer surface of the thermal transfer sheet and the transfer material.

  By the way, in a thermal transfer sheet, when printing is performed by bringing a thermal head into direct contact with a base material, sticking may occur during scanning due to frictional force generated between the base material and the thermal head, resulting in poor printing. . Further, the base material is fused to the thermal head by heat at the time of printing, which prevents the thermal transfer sheet from running and causes sticking, and in some cases, may cause sheet breakage. In order to prevent these problems, in the thermal transfer sheet, the surface of the substrate that comes into contact with the thermal head (that is, the surface opposite to the surface on which the color material layer is provided) is improved in heat resistance and running stability by imparting slipperiness. For the purpose, a heat resistant slipping layer is provided.

  The above heat-resistant slipping layer is formed by applying a coating solution in which a binder resin, a phosphate ester-based surfactant that is a slipping component, a lubricant such as talc, or the like is dissolved or dispersed in a suitable solvent, to a base material, It is formed by drying. For example, in JP-A-2009-61679, by using a polyvinyl acetal resin and a polyisocyanate as a binder resin, the hydroxyl group and the isocyanate group of polyvinyl acetal are cross-linked so that the coating strength of the heat-resistant slipping layer is increased. Thermal transfer sheets with improved heat resistance have been proposed. When such a binder resin is used, a certain amount of time is required for the crosslinking reaction to proceed. Therefore, the thermal transfer sheet is formed by a so-called offline process in which a colorant layer is formed after forming a heat-resistant slipping layer on the substrate. It needs to be manufactured.

  On the other hand, it has been proposed to use a polyamide resin or a silicone-modified polyamide resin as a binder resin for the heat-resistant slipping layer so that the thermal transfer sheet can be produced by an in-line process (for example, JP 2009-132089 A). . However, when the heat resistant slipping layer is formed using the resin as described above, although the heat transfer sheet can be manufactured in an inline process, the heat resistance of the heat resistant slipping layer is higher than that of the heat transfer sheet manufactured by the offline process. In some cases, it was inferior. In addition, the silicone component may bleed out from the heat resistant slipping layer, and depending on the storage state of the thermal transfer sheet, the dye may move from the colorant layer to the heat resistant slipping layer and move to other color portions of the colorant layer. In some cases, a so-called kickback phenomenon occurs in which re-transition occurs.

JP 2009-61679 A JP 2009-132089 A

  In a thermal transfer sheet that forms a heat-resistant slip layer using a binder resin composed of a polyvinyl acetal resin and a polyisocyanate, the cross-linking reaction between the polyvinyl acetal resin and the polyisocyanate is promoted in order to switch from an offline process to an inline process. Therefore, it is necessary to increase the curing rate. Recently, the present inventors have found that the phosphate ester surfactant added to the binder resin as a slipping component inhibits the reactivity of the polyisocyanate, and as a result, the crosslinking reaction takes time. As well as finding out, by using a specific binder resin, it was found that a heat transfer slip layer can be formed by an in-line process to produce a thermal transfer sheet, and the kickback phenomenon can be suppressed. The present invention is based on this finding.

  Therefore, the object of the present invention is to form a heat-resistant slipping layer by an in-line process even when a binder resin comprising a hydroxyl group-containing thermoplastic resin such as a polyvinyl acetal resin and a polyisocyanate is used. An object of the present invention is to provide a thermal transfer sheet capable of suppressing the back phenomenon.

The thermal transfer sheet according to the present invention comprises a base material, a color material layer provided on one surface of the base material, and a heat-resistant slip provided on the surface of the base material opposite to the surface provided with the color material layer. A thermal transfer sheet comprising a layer,
The heat-resistant slipping layer comprises at least a binder resin comprising a hydroxyl group-containing thermoplastic resin and a polyisocyanate resin, a lubricant, and polyethylene wax;
The hydroxyl value in the hydroxyl group-containing thermoplastic resin is 9% by mass or more,
The molar ratio (-NCO / -OH) between the isocyanate group in the polyisocyanate resin and the number of hydroxyl groups in the hydroxyl group-containing thermoplastic resin is 0.3 to 2.0. It is.

  Moreover, as an aspect of the present invention, the hydroxyl group-containing thermoplastic resin is preferably a polyvinyl butyral resin and / or a polyvinyl acetal resin.

  In the embodiment of the present invention, the lubricant is preferably composed of zinc stearate and zinc stearyl phosphate.

  Moreover, as an aspect of the present invention, the binder resin is preferably contained in the heat-resistant slipping layer in an amount of 30 to 90% by mass in terms of solid content.

  Furthermore, as an aspect of the present invention, the polyethylene wax is preferably contained in the heat-resistant slipping layer in an amount of 1 to 30% by mass in terms of solid content.

  In the present invention, as the binder resin constituting the heat resistant slipping layer, a resin comprising a hydroxyl group-containing thermoplastic resin having a hydroxyl value of 9% by mass or more and a polyisocyanate resin is used. It is possible to realize a thermal transfer sheet that can be formed by an in-line process and can also suppress a kickback phenomenon.

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

  The thermal transfer sheet according to the present invention comprises a base material, a color material layer provided on one surface of the base material, and a heat-resistant slip provided on the surface of the base material opposite to the surface provided with the color material layer. And a layer. FIG. 1 is a schematic cross-sectional view showing one embodiment of a thermal transfer sheet according to the present invention. A yellow color material layer (Y), a magenta color material layer (M), and a cyan color material are formed on one surface of a substrate 2. The color material layer 3 composed of three layers (C) is repeatedly provided in the surface order, and the heat resistant slipping layer 4 is provided on the other surface of the substrate 2.

  For example, a primer layer (adhesive layer) that can be described later is provided between the base material 2 and the heat-resistant slipping layer 4 or the base material 2 and the color material layer 3 are not limited to the layer structure shown in FIG. A primer layer (adhesive layer) may be provided between them, or a black color material layer (Bk) may be provided as the color material layer 3 in addition to the three types Y, M, and C. Alternatively, a protective layer-integrated thermal transfer sheet in which Y, M, C, BK, and a protective layer are repeatedly formed in the surface order on the side where the color material layer is provided may be used. Hereinafter, each member constituting the thermal transfer sheet will be described.

<Heat resistant slip layer>
In the thermal transfer sheet according to the present invention, a heat-resistant slipping layer is provided on one surface of the substrate. This heat-resistant slip layer improves the slip of the thermal transfer sheet when it is not heated to enable high-speed printing, and improves resistance to heat from the thermal head during high-speed printing. In the present invention, this heat-resistant slipping layer contains a hydroxyl group-containing thermoplastic resin having a hydroxyl value of 9% by mass or more and a polyisocyanate resin, and the isocyanate group in the polyisocyanate resin and the hydroxyl group-containing heat. Binder resin having a molar ratio (-NCO / -OH) to the number of hydroxyl groups in the plastic resin in the range of 0.3 to 2.0, a lubricant comprising zinc stearate and / or zinc stearyl phosphate, and polyethylene At least a wax. In the present specification, the “hydroxyl value” of the hydroxyl group-containing thermoplastic resin means the ratio of the monomer component having a hydroxyl group in the resin polymer, and the monomer component having a hydroxyl group with respect to the total mass of the resin polymer. It is a value calculated as a mass ratio (mass%).

  As described above, in the manufacturing process of the thermal transfer sheet, a sheet having a heat-resistant slip layer formed on one side of the substrate is prepared once, and then the side of the sheet on which the heat-resistant slip layer is provided is When a color material layer is formed on the opposite surface (that is, when a thermal transfer sheet is produced off-line), it is possible to spend a sufficient amount of time when forming the heat-resistant slip layer. As a resin binder that constitutes, a mixture of a polyvinyl butyral resin and a polyisocyanate resin has been used. However, after forming a heat-resistant slipping layer on one side of the substrate (or at the same time), a color material layer is formed on the opposite side of the substrate (that is, a thermal transfer sheet is produced in an inline process). In such a case, the binder resin in the heat resistant slipping layer needs to be sufficiently cured in a short time. Therefore, as described in JP-A-2009-132089, a polyamideimide resin or a polyamideimide silicone resin is used. Etc. were used. However, when a polyamide-based resin is used as a binder, the heat resistance from the thermal head during printing may be insufficient depending on the heating temperature.

  In addition, if the thermal transfer sheet is stored in a roll form, the dye in the color material layer oozes out and adheres to the surface of the heat-resistant slipping layer, and the so-called kickback may occur, causing the thermal transfer sheet to become dirty. there were. In the present invention, even when a thermal transfer sheet is produced by an in-line process, a thermal transfer sheet having excellent heat resistance can be obtained by using the above-described binder resin, and the binder resin and the specific above-described By combining with a lubricant, the occurrence of kickback can be suppressed even when the thermal transfer sheet is stored in a roll form.

  Examples of the hydroxyl group-containing thermoplastic resin used as the binder include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, and nitrified cotton, polyvinyl alcohol, polyvinyl pyrrolidone, and polymethacrylic acid. Vinyl resins such as ethyl esters, polyacrylamides, acrylonitrile-styrene copolymers, polyvinyl acetal resins such as polyvinyl butyral resins and polyacetoacetal resins, polyamideimide resins, polyurethane resins, silicone-modified or fluorourethane resins, acrylic resins, etc. Is mentioned. Among these, polyvinyl acetal resins such as polyvinyl butyral resins and polyacetoacetal resins having many hydroxyl groups in the molecule can be suitably used.

  In particular, in polyvinyl acetal resins, polyvinyl acetal used in conventional off-line production sometimes has insufficient heat resistance of a thermal transfer sheet when applied to in-line production, but has a hydroxyl value of 9% by mass. By using the above hydroxyl group-containing thermoplastic resin, the heat resistance of the thermal transfer sheet can be remarkably improved. In the present invention, the hydroxyl value of the hydroxyl group-containing thermoplastic resin is preferably 25% by mass or less. When the hydroxyl value of polyvinyl acetal exceeds 25% by mass, the resin is difficult to dissolve in a solvent such as ethyl acetate or toluene that dissolves the binder resin. Specifically, as a polyvinyl acetal resin having a hydroxyl value of 9 to 25% by mass, # 3000-1, # 3000-2, # 3000-4, # 3000-K, # 4000- manufactured by Denki Kagaku Co., Ltd. 1, # 4000-2 and the like.

  The polyisocyanate resin used as the curing agent crosslinks the hydroxyl group-containing thermoplastic resin using the hydroxyl group to improve the coating strength or heat resistance of the heat resistant slipping layer. Various polyisocyanates have been conventionally known, and among them, 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 polyisocyanate is in such an amount that the molar ratio (-NCO / -OH) between the isocyanate group in the polyisocyanate and the number of hydroxyl groups in the hydroxyl group-containing thermoplastic resin is in the range of 0.3 to 2.0. Added. If the amount of polyisocyanate used is too small, the crosslinking density is low and the heat resistance becomes insufficient, which is not preferable. On the other hand, if the amount of polyisocyanate used is too large, it becomes difficult to control the shrinkage of the coating film formed, the time for curing becomes long, unreacted isocyanate groups remain in the heat resistant slipping layer, and air This causes problems such as reacting with the water content. The specific amount of polyisocyanate used is suitably in the range of 5 to 200 parts by mass with respect to 100 parts by mass of the above-mentioned hydroxyl group-containing thermoplastic resin constituting the heat-resistant active layer.

  The lubricant contained in the heat resistant slipping layer has a function of improving the slipperiness of the heat resistant slipping layer, and can have sufficient slipping property particularly when heated by a thermal head (printing). Various known materials can be used as the lubricant, but metal soap is preferably used as the lubricant. By including metal soap as a lubricant, it is possible to reduce the coefficient of friction between the thermal transfer sheet and the thermal head when printing with intermediate or high transfer energy. Examples of such metal soap include polyvalent metal salts of alkyl phosphates and metal salts of alkyl carboxylic acids. In the present invention, among these metal salts, zinc stearate and / or zinc stearyl phosphate can be preferably used.

  The polyethylene wax contained in the heat resistant slipping layer improves the slipperiness of the heat resistant slipping layer, and particularly has a function of improving the slipperiness of the heat resistant slipping layer when not heated. As the polyethylene wax, polyethylene wax particles having a density of 0.94 to 0.97 (polyethylene wax finely divided into particles) can be suitably used. Polyethylene wax includes high-density or low-density polyethylene wax, and low-density polyethylene contains many ethylene polymer branches due to its structure, whereas high-density polyethylene is relatively polyethylene. It is mainly composed of a straight chain structure.

  As the polyethylene wax used in the heat-resistant slip layer of the thermal transfer sheet of the present invention, those having an average particle size of 15 μm or less, particularly 7 to 12 μm, can be suitably used. If the particle size is too small, the function of imparting the slipperiness of the heat resistant slipping layer will be reduced. On the other hand, if the particle size is too large, debris will easily adhere to the thermal head. In addition, the shape of the polyethylene wax particles can be spherical, square, columnar, needle-like, plate-like, indefinite shape, etc., but in the present invention, from the viewpoint of imparting the lubricity of the heat-resistant slipping layer, It is preferable to take the form of a spherical particle, and it becomes difficult for the residue to adhere to the thermal head while imparting excellent lubricity. By setting the average particle diameter of the polyethylene wax within the above range, the high-density polyethylene wax protrudes from the surface of the heat-resistant slipping layer, so that the thermal transfer sheet can have an appropriate slipping property.

  The polyethylene wax particles are preferably contained at a ratio of 0.5 to 8% by mass with respect to the total solid content (100% by mass) of the heat-resistant slip layer. If the content is too small, the slipping property of the heat resistant slipping layer is lowered, and if the content is too large, debris tends to adhere to the thermal head. Moreover, it is preferable that melting | fusing point of polyethylene wax is 110-140 degreeC. If the melting point is too low, the preservability of the thermal transfer sheet is lowered, or the polyethylene wax itself melts in the drying step after coating the heat resistant slipping layer, thereby inhibiting the slipping property of the heat resistant slipping layer, On the other hand, if the melting point is too high, the transfer of the coloring material at the time of thermal transfer tends to be non-uniform due to the surface irregularities of the heat-resistant slip layer. The melting point can be measured using a conventionally known method such as a differential scanning calorimeter (DSC).

  The heat-resistant slipping layer contains the above-mentioned lubricant and polyethylene wax in order to provide slipping properties at the time of printing and non-printing, but for the auxiliary adjustment of the slipperiness, inorganic or organic Fine particles or silicone oil can be added. Examples of the inorganic fine particles 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 fine particles such as graphite, nitrate and boron nitride. Organic fine particles include acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, polystyrene resin, nylon resin, etc., or crosslinked resin obtained by reacting these with a crosslinking agent. Examples thereof include fine particles.

  Any of the above inorganic or organic fine particles preferably has an average particle size of about 0.5 to 3 μm. The inorganic or organic fine particles are desirably used at a ratio of 5 to 40 parts by mass with respect to 100 parts by mass of the hydroxyl group-containing thermoplastic resin. If the addition amount is too small, the slipperiness is insufficient. If the amount is too large, the flexibility and film strength of the heat-resistant slip layer formed are lowered. In order to provide a heat resistant slipping layer on a base sheet, the above components are dissolved in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene, etc., and used as a heat resistant slipping layer forming ink. It forms on a base material sheet by the usual suitable printing methods, such as a coater and a wire bar, and the apply | coating method. Next, drying is performed by heating to a temperature of 30 ° C. to 80 ° C., and a resin having a hydroxyl group which is an active hydrogen group is reacted with polyisocyanate to form a heat-resistant slipping layer.

  The thickness of the heat resistant slipping layer is 0.05 to 5 μm, preferably 0.1 to 1 μm. If this film thickness is less than 0.05 μm, the effect as a heat-resistant slip layer is not sufficient, and if it is more than 1 μm, heat transfer from the thermal head to the heat transferable color material layer becomes worse, and the print density This causes the disadvantage of lowering. When providing a heat resistant slipping layer on a base material sheet, it is preferable to heat in order to promote the crosslinking reaction between the hydroxyl group-containing thermoplastic resin and the polyisocyanate. In order to prevent heat from being affected, it is preferable to provide the colorant layer after providing the heat-resistant slip layer on the base sheet.

<Base material>
The thermal transfer sheet according to the present invention has the above-mentioned heat-resistant slip layer provided on a substrate. The base material may be any material as long as it has a conventionally known heat resistance and strength. For example, a polyethylene terephthalate film, a 1,4-polycyclohexylenedimethylene terephthalate film, a polyethylene naphthalate film, Polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film, etc. The resin film etc. are mentioned.

  The substrate generally has a thickness of about 0.5 to 50 μm, preferably about 1.5 to 10 μm. The base material 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 preferred because of its low cost. Moreover, you may form an undercoat layer (primer layer) in the one surface or both surfaces as needed. The primer treatment can be performed, for example, by applying a primer solution to an unstretched film at the time of film formation by melt extrusion of a plastic film and then stretching the film. Moreover, it is also possible to apply and form a primer layer (adhesive layer) between the base material and the above-described heat-resistant slip layer. The primer layer may be, for example, a polyester resin, a polyacrylate ester resin, a polyvinyl acetate resin, a polyurethane resin, a styrene acrylate resin, a polyacrylamide resin, a polyamide resin, a polyether resin, or a polystyrene resin. , Polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinyl alcohol resin, vinyl resin such as polyvinylidene chloride resin, polyvinyl acetal resin such as polyvinyl acetoacetal and polyvinyl butyral, cellulose resin, etc. be able to.

<Color material layer>
The thermal transfer sheet according to the present invention is provided with a color material layer on the surface opposite to the surface provided with the heat-resistant slip layer of the above-described base material. When the desired image is monochromatic, the thermal transfer sheet of the present invention may be formed of only one color layer appropriately selected as the color material layer, or when the desired image is a full color image, As the color material layer, cyan, magenta, and yellow (and black as necessary) can be selected and formed.

  When the thermal transfer sheet of the present invention is a sublimation type thermal transfer sheet, a layer containing a sublimable dye is formed as a color material layer, and when it is a heat melting type thermal transfer sheet, a pigment or the like is used as a color material layer. A hot-melt ink layer colored with is formed. Hereinafter, the case where the thermal transfer sheet according to the present invention is a sublimation type thermal transfer sheet will be described as an example. However, the thermal transfer sheet may be a heat melting type, and the present invention is not limited to the sublimation type thermal transfer sheet.

  The sublimation dye used in the sublimation dye layer is not particularly limited, and conventionally known dyes can be used. Examples of the sublimable dye include diarylmethane dyes; triarylmethane dyes; thiazole dyes; merocyanine dyes; pyrazolone dyes; methine dyes; indoaniline dyes; Azomethine dyes such as imidazoazomethine and pyridone azomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes such as dicyanostyrene and tricyanostyrene; thiazine dyes; azine dyes; acridine dyes; benzeneazo dyes; , Thiophenazo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, disazo and other azo dyes; spiropyran dyes; Fluorane dyes; rhodamine lactam dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes; and the like. More specifically, compounds exemplified in JP-A-7-149062 Can be mentioned.

  In the dye layer, the sublimable dye is 5 to 90% by mass, preferably 20 to 80% by mass, based on the total solid content of the dye layer.

  When the amount of the sublimable dye used is less than the above range, the print density may be lowered, and when it exceeds the above range, the storage stability may be lowered.

  As the binder resin for supporting the dye, generally, a resin having heat resistance and appropriate affinity with the dye can be used. Examples of the binder resin include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose butyrate; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal, polyvinyl pyrrolidone Vinyl resins such as poly (meth) acrylates, poly (meth) acrylamides and the like; polyurethane resins; polyamide resins; polyester resins; Among the binder resins described above, cellulose resins, vinyl resins, acrylic resins, urethane resins, polyester resins, and the like are preferable, and vinyl resins are more preferable, from the viewpoint of excellent heat resistance, dye migration, and the like. Polyvinyl butyral, polyvinyl acetoacetal and the like are particularly preferable.

  The dye layer may use additives such as a release agent, inorganic fine particles, and organic fine particles as desired. Examples of the mold release agent include silicone oil and phosphate ester. Inorganic fine particles include carbon black, aluminum, molybdenum disulfide and the like. Examples of the organic fine particles include polyethylene wax.

  The above-mentioned dye layer is prepared by dissolving or dispersing the above-described dye and binder resin in an appropriate organic solvent or water together with additives to be added as necessary, and further, a gravure printing method, It can be formed by applying the coating liquid on one surface of the substrate and drying it by a known means such as a screen printing method or a reverse roll coating printing method using a gravure plate.

Examples of the organic solvent include toluene, methyl ethyl ketone, ethanol, isopropyl alcohol, cyclohexanone, dimethylformamide [DMF] and the like. The coating amount of the dye layer, dried 0.2~6.0g / ^{m 2} in solid standard, preferably 0.2 to 3.0 g / ^{m 2} approximately.

<Other layers>
If the thermal transfer sheet according to the present invention is provided with a color material layer on one side of a substrate and a heat-resistant slipping layer on the other side of the substrate, an adhesive layer and a release layer as a transfer protective layer Further, other layers such as a release layer or an undercoat layer may be provided. When the transfer protective layer is formed in the surface order with the color material layer described above, the protective layer protecting the image surface can be transferred after image formation.

  The configuration and preparation of the transfer protective layer are not particularly limited, and can be selected from conventionally known techniques according to the characteristics of the base material sheet, the color material layer, and the like to be used. The undercoat layer is not particularly limited, and a composition that improves the adhesion between the base material and the color material layer and the transfer efficiency of the dye can be appropriately selected and provided.

<Image Forming Method Using Thermal Transfer Sheet>
The thermal transfer sheet according to the present invention can be printed by heating and pressurizing a portion corresponding to the printing portion from the heat-resistant slipping layer side of the above-mentioned substrate using a thermal head or the like, and transferring the color material to the transfer material. it can. The printer used when performing thermal transfer is not particularly limited, and a known thermal transfer printer can be used.

  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 provided with a dye receiving layer on one surface on a substrate. Hereinafter, each layer constituting the thermal transfer image receiving sheet will be described.

  The base material layer constituting the thermal transfer image-receiving sheet has a function of holding the receiving layer, but since heat is applied at the time of thermal transfer, it preferably has a mechanical strength that does not hinder handling even in a heated state. . The material of the base material layer is not particularly limited, and examples thereof include capacitor paper, glassine paper, sulfuric acid paper, synthetic paper (polyolefin-based, polystyrene-based, etc.), high-quality paper, art paper, coated paper, Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, silver salt photographic printing paper coated with polyethylene on both sides Resin-coated paper used as a base material, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride , Polyvinylidene chloride, etc. Seed plastic film or sheet can be used, also white pigment, these synthetic resins, formed by adding a filler, a film (porous film) having fine voids (microvoids) inside the substrate can also be used.

  Moreover, the laminated body by arbitrary combinations of an above-described material can also be used as a base material layer. Examples of typical laminates include cellulose fiber paper and synthetic paper, or synthetic paper in which cellulose fiber paper and plastic film or sheet are laminated. Such laminated synthetic paper may be a two-layer body, but in order to give the texture and texture of the base material, synthetic paper, plastic film and porous film were bonded to both sides of cellulose fiber paper (used as a core material). It may be a three-layer body or a laminate of three or more layers. Moreover, the laminated body which coated the resin layer in which the hollow particle was disperse | distributed on the surfaces, such as a coated paper, resin coated paper, and a plastic film, and provided heat insulation may be sufficient.

  The method for laminating the laminate is not limited to methods such as dry lamination, wet lamination, and extrusion. Moreover, as a method for laminating the hollow particle layer as described above, application means such as gravure coat, comma coat, blade coat, die coat, slide coat, curtain coat, etc. can be used, but it is not limited to these.

  The thickness of these bonding base material or laminated base material may be arbitrary, and a thickness of about 10 to 300 μm is generally common. Moreover, when the above-mentioned base material has poor adhesion to the layer formed on the surface, it is preferable to subject the surface to various primer treatments and corona discharge treatments. Moreover, when providing a hollow particle layer, it is preferable to carry out multilayer coating simultaneously with a receiving layer or another layer by slide coating or curtain coating from a viewpoint of adhesiveness or manufacturing efficiency.

  The dye receiving layer provided on the base material layer 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, acrylic-styrene resin, cellulose resin, polysulfone resin, polyvinyl chloride resin, vinyl chloride- Acrylic resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyurethane resin, polystyrene resin, polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer Examples thereof include resins, epoxy resins, polyvinyl alcohol resins, gelatin and derivatives thereof. Two or more of these resin materials may be mixed and used.

  The thermal transfer image-receiving sheet may contain a release agent in the dye-receiving layer in order to improve releasability from the thermal transfer sheet. Various release agents such as solid waxes such as polyethylene wax, amide wax, Teflon (registered trademark), fluorine-based or phosphate-based surfactant, silicone oil, reactive silicone oil, curable silicone oil, etc. Silicone oil, various silicone resins, and the like can be mentioned, and among these, silicone oil is preferable. An oily oil can be used as the silicone oil, but a curable oil is preferred. Examples of the curable silicone oil include a reaction curable type, a photo curable type, and a catalyst curable type, and a reaction curable type and a catalyst curable type silicone oil are particularly preferable.

  The addition amount of these curable silicone oils is preferably 0.5 to 30% by mass of the resin constituting the dye receiving layer. Alternatively, the release agent layer may be provided by partially dissolving and dispersing the release agent in a suitable solvent on the surface of the receptor layer and then drying. The thickness of the release agent layer is preferably 0.01 to 5.0 μm, particularly preferably 0.05 to 2.0 μm. In addition, when silicone oil is added and formed when forming the dye receiving layer, the release agent layer can be formed even if the silicone oil bleed out on the surface after coating is cured. In forming the dye receiving layer, titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica, etc. are used for the purpose of improving the whiteness of the dye receiving layer and further enhancing the clarity of the transferred image. Pigments and 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.

  Between the base material layer and the dye receiving layer, for the purpose of imparting adhesiveness between the dye receiving layer and the base material, whiteness, cushioning property, concealing property, antistatic property, anti-curling property, etc., conventionally known Any intermediate layer can be provided. The binder resin used for 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. -Vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer resin, polyethylene resin, polypropylene resin, etc. Of the resins having an active hydroxyl group, those isocyanate cured products can be used as a binder.

Moreover, it is preferable to add fillers, such as a titanium oxide, a zinc oxide, magnesium carbonate, a calcium carbonate, to an intermediate | middle layer in order to provide whiteness and concealment property. In addition, 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 resistance 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.

  As the resin binder contained in the hollow layer, it is preferable to use an emulsion in which a water-insoluble hydrophobic polymer is dispersed as fine particles in a water-soluble dispersion medium, or a hydrophilic binder. As such an emulsion, acrylic, polyester, polyurethane, SBR (styrene-butadiene rubber), polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, polyolefin, or the like may be used. It is possible to use a mixture of two or more of these as required. Examples of hydrophilic binders include gelatin and derivatives thereof, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, dextran, dextrin, polyacrylic acid and salts thereof, agar, κ-carrageenan, λ. -Carrageenan, iota-carrageenan, casein, xanthene gum, locust bean gum, alginic acid and gum arabic can be mentioned, with gelatin being particularly preferred. By using such a hydrophilic binder, the interlayer adhesion between the dye receiving layer and the layer in contact with the dye receiving layer can be improved. In particular, when each layer is formed by an aqueous coating method and a simultaneous multilayer coating method, the viscosity of each coating solution can be adjusted to a desired range by using gelatin as a binder resin, and a desired film thickness can be obtained. . In the present invention, commercially available gelatin can also be used, and for example, RR, R, CLV (manufactured by Nitta Gelatin Co., Ltd.) and the like are preferable.

  EXAMPLES Next, although an Example is given and this invention is demonstrated still in detail, this invention is not limited to these Examples. In addition, unless otherwise indicated, a part or% is a mass reference | standard.

Example 1
On one surface of a base sheet of a polyethylene terephthalate film having a thickness of 4.5 μm that has been subjected to easy adhesion treatment, the coating amount 1 for a heat-resistant slipping layer having the following composition is applied in an amount of 0.5 g / m ^{2 in} terms of solid content. The heat resistant slipping layer was formed by applying and drying.
<Coating liquid 1 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 6.00 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 8.00 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.) 3.00 parts Zinc stearate (SZ-PF, Sakai Chemical Industry Co., Ltd.) 3.00 parts Filler (Microace P-3, 1.50 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.00 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 12.58 parts Toluene 62.92 parts

Next, a primer layer coating solution having the following composition is applied to a part of the surface of the base sheet opposite to the side provided with the heat-resistant slip layer by a gravure printing machine so that the dry coating amount is 0.10 g / m. ^The primer layer was formed by coating and drying so as to be ² .
<Primer layer coating solution>
Colloidal silica (particle size 4-6nm, solid content 10%) 30 parts (Snowtech ° OXS, manufactured by Nissan Chemical Industries, Ltd.)
Polyvinylpyrrolidone resin (K-90, manufactured by ISP) 3 parts Water 50 parts Isopropyl alcohol 17 parts

Subsequently, a yellow dye layer coating liquid (Y), a magenta dye layer coating liquid (M), and a cyan dye layer coating liquid (C) having the following composition are applied on the primer layer by a gravure printing machine. The coating was applied and dried so that the dry coating amount was 0.6 g / m ² .

<Yellow dye layer coating liquid (Y)>
Disperse dye (Disperse Yellow 231) 2.5 parts Disperse dye (Yellow dye A represented by the following chemical formula) 2.5 parts Binder resin 4.5 parts (Polyvinylacetoacetal resin KS-5, manufactured by Sekisui Chemical Co., Ltd.) )
Phosphate-based surfactant 0.1 part (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
Polyethylene wax 0.1 part Methyl ethyl ketone 45.0 parts Toluene 45.0 parts

<Magenta dye layer coating solution (M)>
Disperse dye (MS Red G) 1.5 parts Disperse dye (Macrolex Red Violet R) 2.0 parts Binder resin 4.5 parts (Polyvinylacetoacetal resin KS-5, manufactured by Sekisui Chemical Co., Ltd.)
Phosphate-based surfactant 0.1 part (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
Polyethylene wax 0.1 part Methyl ethyl ketone 45.0 parts Toluene 45.0 parts

<Cyan dye layer coating solution (C)>
Disperse dye (Solvent Blue 63) 2.5 parts Disperse dye (Disperse Blue 354) 2.5 parts Binder resin (Polyvinylacetoacetal resin KS-5, manufactured by Sekisui Chemical Co., Ltd.) 4.5 parts Phosphate ester Surfactant 0.1 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
Polyethylene wax 0.1 part Methyl ethyl ketone 45.0 parts Toluene 45.0 parts

In addition, a part of the surface of the base sheet opposite to the side on which the heat-resistant slip layer is provided is coated with a release layer coating liquid having the following composition using a gravure printing machine at a solid content of 1.0 g / m. ^After coating and drying at a ratio of ² to form a release layer, the above primer layer coating solution is applied onto the release layer by a gravure printing machine so that the dry coating amount is 0.10 g / m ² ). Applied to and dried to form a primer layer, and on the primer layer, a protective layer coating solution having the following composition was applied at a rate of 1.5 g / m ^{2 in} terms of solid content using a gravure printer, Dried to form.

<Release layer coating solution>
Urethane resin (Chrisbon 9004, manufactured by DIC Corporation) 20.0 parts Polyvinylacetoacetal resin (KS-5, manufactured by Sekisui Chemical Co., Ltd.) 5.0 parts Dimethylform alumide 80.0 parts Methyl ethyl ketone 120.0 parts

<Coating liquid for protective layer>
Polyester resin (Byron 200, manufactured by Toyobo Co., Ltd.) 69.6 parts Acrylic copolymer reactively bonded with a reactive ultraviolet absorber (UVA635L, manufactured by BASF Japan) 17.4 parts Silica (Silicia 310, manufactured by Fuji Silysia) 25 Methyl ethyl ketone 20 parts Toluene 20 parts

  As described above, the heat-resistant slipping layer is provided on one surface of the base material layer, the primer layer / dye layer (Y, M, C) is laminated on the other surface of the base material layer, and the release layer. A thermal transfer sheet provided with a laminate of / primer layer / protective layer was obtained.

Example 2
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 2 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 2 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 8.53 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 10.97 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd. 2.44 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 0.37 parts Filler (Microace P-3, Japan 1.22 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 0.98 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Example 3
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 3 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 3 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 7.21 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content: 100% by mass, NCO = 17.3% by mass) 5.65 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 3.32 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 3.32 parts Filler (Microace P-3, 1.67 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.34 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Example 4
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat-resistant slipping layer coating liquid 1 was replaced with the heat-resistant slipping layer coating liquid 4 having the following composition and a heat-resistant slipping layer was formed.
<Coating fluid 4 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 7.23 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
9.41 parts of polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.42 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 1.42 parts Filler (Microace P-3, 1.68 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.35 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Example 5
A thermal transfer sheet was produced in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 5 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 5 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 8.53 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 6.69 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.67 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 1.67 parts Filler (Microace P-3, 1.98 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.96 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Example 6
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 6 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 6 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 11 mass%) 8.00 parts (# 3000-K, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content: 100% by mass, NCO = 17.3% by mass) 6.00 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.) 3.00 parts Zinc stearate (SZ-PF, Sakai Chemical Industry Co., Ltd.) 3.00 parts Filler (Microace P-3, 1.50 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.00 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 12.59 parts Toluene 62.92 parts

Example 7
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 7 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 7 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 11 mass%) 10.50 parts (# 3000-K, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 4.72 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.) 1.67 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 1.67 parts Filler (Microace P-3, 1.98 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.96 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Comparative Example 1
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 8 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 8 for heat resistant slipping layer>
Polyamideimide resin (solid content 25%) 13 parts (HR-15ET, manufactured by Toyobo Co., Ltd.)
Polyamidoimide silicone resin (solid content 25% 13 parts (HR-14ET, manufactured by Toyobo Co., Ltd.)
Silicone oil (solid content 100%) 0.7 part (KF965-100, manufactured by Shin-Etsu Chemical Co., Ltd.)
Zinc stearyl phosphate (solid content 100%) 2.6 parts (LBT-1870 purification, Sakai Chemical Industry Co., Ltd.)
Zinc stearate (GF-200, manufactured by NOF Corporation, solid content 100%) 2.6 parts Talc (Microace P-3, manufactured by Nippon Talc Co., Ltd., solid content 100%) 2.6 parts Ethanol 32.8 parts Toluene 32.7 parts

Comparative Example 2
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 9 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 9 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 2.0 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 5.0 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Phosphate ester surfactant 1.3 parts (Plysurf A208N, Daiichi Kogyo Seiyaku Co., Ltd.)
Talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.) 0.3 part Methyl ethyl ketone 45.7 parts Toluene 45.7 parts

Comparative Example 3
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 10 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 10 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 4.50 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content: 100% by mass, NCO = 17.3% by mass) 12.59 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1870 refinement, manufactured by Sakai Chemical Industry Co., Ltd.) 2.11 parts Zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.) 2.11 parts Filler (Microace P-3, 1.06 parts polyethylene wax (melting point 110-118 ° C., average particle size 10 μm) 2.13 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Comparative Example 4
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 11 having the following composition and a heat resistant slipping layer was formed.
<Coating liquid 11 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 7.96 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 10.37 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1870 purification, Sakai Chemical Industry Co., Ltd.) 0.31 part Zinc stearate (SZ-PF, Sakai Chemical Industry Co., Ltd.) 0.31 part Filler (Microace P-3, 1.06 parts polyethylene wax (melting point 110-118 ° C., average particle size 10 μm) 2.13 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 62.92 parts Toluene 12.58 parts

Comparative Example 5
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the heat resistant slipping layer coating liquid 1 was replaced with the heat resistant slipping layer coating liquid 12 having the following composition and a heat resistant slipping layer was formed.
<Coating fluid 12 for heat resistant slipping layer>
Polyvinyl butyral resin (hydroxyl value 20% by mass) 12.00 parts (# 3000-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
Polyisocyanate (solid content 100% by mass, NCO = 17.3% by mass) 2.00 parts (Bernock D750-45, manufactured by Dainippon Ink & Chemicals, Inc.)
Zinc stearyl phosphate (LBT-1870 purification, Sakai Chemical Industry Co., Ltd.) 3.00 parts Zinc stearate (SZ-PF, Sakai Chemical Industry Co., Ltd.) 3.00 parts Filler (Microace P-3, 1.50 parts polyethylene wax (melting point: 110 to 118 ° C., average particle size: 10 μm) 3.00 parts (polywax 3000, manufactured by Toyo Petrolite Co., Ltd.)
Methyl ethyl ketone 12.58 parts Toluene 62.92 parts

  In the heat resistant slipping layer coating liquids 1 to 12, the molar ratio of isocyanate groups to hydroxyl groups of polyvinyl butyral resin (-NCO / -OH), the content of binder resin (polyvinyl butyral resin and polyisocyanate), lubricant ( The contents of zinc stearate and zinc stearyl phosphate are as shown in Table 1 below.

Evaluation of heat resistance Each thermal transfer sheet obtained above was combined with a thermal transfer image-receiving sheet for a sublimation printer (CP9000D) manufactured by Mitsubishi Electric Corporation, and the frictional force during printing was measured under the following conditions. In addition, the thermal transfer printer with a frictional force measurement function described in Japanese Patent Application Laid-Open No. 2003-300338 was used for measurement of printing and frictional force.
<Printing conditions>
Thermal head: Toshiba Hokuto Electronics thermal head, head resistance 5020Ω resolution 300 dpi (dots per inch)
Line speed: 1 ms / Line (Resolution in the paper transport direction is 300 lpi (line per inch))
Pulse duty: 90%
Applied voltage: 30.0V
Printing pressure: 40N
Print image: gradation image with a width of 1388 pixels x length of 945 pixels and gradations of 0 to 255 (one pixel corresponds to one dot)

Under the above printing conditions, the solid printing pattern (high density area) with the highest printing gradation value and the solid pattern (intermediate density area) with 128/255 gradation (gray) were printed, and the dynamic friction coefficient at that time was measured. The heat resistance was evaluated according to the following evaluation criteria.
1: Dynamic friction coefficient is 0.5 or more 2: Dynamic friction coefficient is 0.4 or more and less than 0.5 3: Dynamic friction coefficient is 0.4 or less

  Also, under the above conditions, change the gradation value to 5 increments, print a solid pattern, and print the highest energy one weaker than the occurrence of defects such as wrinkles, sticking, scratching of the heat resistant slipping layer, etc. Using the gradation values, the printing performance of each thermal transfer sheet was evaluated. It is assumed that the gradation value of the print data corresponds to 100% solid of 255 gradation, and the ratio of the gradation value at the time of printing divided by 255 is the applied energy of the pattern with respect to the maximum applied energy (for example, If the gradation value at the time of printing is 210 gradations, 210/255 = 0.823, that is, 82% solid). Therefore, it can be said that the higher the maximum print gradation value, the higher the applied energy can be withstood. The evaluation results were as shown in Table 1 below.

<Durability evaluation of thermal transfer sheet>
The sublimation transfer printer (CW) manufactured by Citizen System Co., Ltd. using each of the thermal transfer sheets obtained above and the sublimation thermal transfer image receiving sheet for the sublimation transfer printer (CW-01) manufactured by Citizen System Co., Ltd. -01) is used to print a thermal transfer image-receiving sheet with a gradation value of 255/255 (maximum applied energy: black image) with a dye layer of Ye, Mg, and Cy, and whether or not the thermal transfer sheet is broken after printing. It was examined visually. The evaluation criteria were as follows.
1: The thermal transfer sheet after printing has considerable breakage and considerable elongation.
2: Fracture is slightly seen in the thermal transfer sheet after printing, but almost no elongation is seen.
3: Although there is some breakage in the thermal transfer sheet after printing, no elongation is seen at all.
4: No breakage and no elongation at all on the thermal transfer sheet after printing.
The evaluation results were as shown in Table 1 below.

Back Evaluation The heat-resistant slipping layer and the magenta dye layer of each of the thermal transfer sheets obtained above were opposed to each other, subjected to a load of 20 kg / cm ² and stored for 96 hours in an environment of 40 ° C. and 90% humidity. The dye in the dye layer was transferred (kicked) to the layer side. The heat-resistant slipping layer and the protective layer were made to face each other, and a load of 20 kg / cm ² was applied, and the layer was stored for 24 hours in an environment of 50 ° C. and humidity of 20%. Thereafter, the protective layer transfer body to which the dye of the heat-resistant slipping layer has transferred (back) and the image receiving surface of the image receiving paper (color ink / paper set KP-36IP, manufactured by Canon Inc.) are superposed, and a laminating tester (Lamipacker) Transfer was performed at 110 ° C. and 4 mm / sec / line using LPD2305PRO (manufactured by Fuji Pla Co., Ltd.). Further, the substrate sheet is peeled off from the image receiving paper, and the hue of the transfer portion is measured using Gretag Spectrolino (D65 light source, viewing angle 2 °) manufactured by Gretag, and the color difference (ΔE ^* ) is calculated by the following formula. Evaluation was based on criteria.
ΔE ^* = ((difference in L ^* value before and after facing) ² + (difference in a ^* value before and after facing) ² + (difference in b ^* value before and after facing) ² ) ^1/2

1: Color difference ΔE ^* between the transfer product transferred from the unpreserved protective layer and the transfer product transferred from the backed protective layer transfer member is 3.5 or more. 2: The transfer product transferred from the non-preserved protective layer and the back The color difference ΔE ^* of the transferred product obtained by transferring the transferred protective layer transfer material is 2.5 or more and less than 3.5 3: The transferred product obtained by transferring the unprotected protective layer and the transferred product obtained by transferring the backed protective layer transfer material less color difference Delta] E ^* is 1.5 or more 2.5 4: unsaved and transcripts transferring the protective layer, the color difference of the transcripts transferred protective layer transfer member was back Delta] E ^* is less than 1.5

The evaluation results were as shown in Table 2 below.

DESCRIPTION OF SYMBOLS 1 Thermal transfer sheet 2 Base material 3 Color material layer 4 Heat resistant slipping layer

Claims (6)

Thermal transfer comprising: a base material; a color material layer provided on one surface of the base material; and a heat-resistant slipping layer provided on a surface opposite to the surface provided with the color material layer of the base material. A sheet,
The heat-resistant slipping layer comprises at least a binder resin comprising a hydroxyl group-containing thermoplastic resin and a polyisocyanate resin, a lubricant, and polyethylene wax;
The hydroxyl value in the hydroxyl group-containing thermoplastic resin is 9% by mass or more,
The molar ratio (-NCO / -OH) between the isocyanate group in the polyisocyanate resin and the number of hydroxyl groups in the hydroxyl group-containing thermoplastic resin is 0.3 to 2.0, Thermal transfer sheet.   The thermal transfer sheet according to claim 1, wherein the hydroxyl group-containing thermoplastic resin is a polyvinyl butyral resin and / or a polyvinyl acetal resin.   The thermal transfer sheet according to claim 1 or 2, wherein the lubricant comprises zinc stearate and zinc stearyl phosphate.   The thermal transfer sheet according to any one of claims 1 to 3, wherein the binder resin is contained in the heat-resistant slipping layer in an amount of 30 to 90% by mass in terms of solid content.   The thermal transfer sheet according to any one of claims 1 to 4, wherein the lubricant is contained in the heat-resistant slipping layer in an amount of 5 to 40% by mass in terms of solid content.   The thermal transfer sheet according to any one of claims 1 to 5, wherein the polyethylene wax is contained in the heat-resistant slipping layer in an amount of 1 to 30% by mass in terms of solid content.

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