JP2011056893A - Thermal transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer sheet which has a good sliding property between a heat-resistant sliding layer and a thermal head, which prevents a problem wherein a wrinkle occurs therein, dregs are apt to accumulate on the thermal head and the thermal head is apt to wear in printing and which has heat resistance. <P>SOLUTION: The thermal transfer sheet includes: a dye layer on one surface of a base material sheet; a hot-melt coloring ink layer and/or a thermal transferring protective layer formed thereon in order; and a heat-resistant sliding layer formed on the other surface of the base material sheet. The heat-resistant sliding layer is formed of two kinds of layers distinguished by different colors. The dye layer is provided at a side opposite from the base material sheet at a position where the heat-resistant sliding layer A is exposed to the surface. The hot-melt coloring ink layer and/or the thermal transferring protective layer are provided at a side opposite from the base material sheet at a position where the heat-resistant sliding layer B is exposed to the surface. The heat-resistant sliding layer A contains a lubricant in a non-curable resin and the heat-resistant sliding layer B contains a filler in a curable resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal transfer sheet. More specifically, the present invention relates to a thermal transfer sheet in which a heat transferable color material layer is formed on one surface of a base sheet and a heat resistant slipping layer is formed on the other surface. The present invention relates to a thermal transfer sheet having good heat resistance that prevents slippage between a layer and a thermal head, prevents wrinkles from being generated on the thermal transfer sheet during printing, and prevents residue from being easily deposited on the thermal head.

  Conventionally, various thermal transfer recording methods are known. Among them, thermal transfer having a dye layer in which a dye for sublimation transfer is used as a recording material and this is supported on a base sheet such as a polyester film with an appropriate binder. A method for forming various full-color images by thermally transferring sublimation dyes from a sheet onto a transfer material that can be dyed with sublimation dyes, for example, a thermal transfer image-receiving sheet in which a dye-receiving layer is formed on paper or plastic film, etc. has been proposed. ing. In this case, as the heating means, the color dots having a large number of three or four colors adjusted by heating with the thermal head of the printer are transferred to the receiving layer of the thermal transfer image receiving sheet, and the multicolored color dots are transferred. To reproduce the full color of the document. The image formed in this way is very clear and excellent in transparency because the coloring material used is a dye, so the resulting image is excellent in the reproducibility and gradation of intermediate colors, It is possible to form a high-quality image similar to an image obtained by offset printing or gravure printing and comparable to a full-color photographic image.

  Such a thermal transfer sheet is heated and recorded by a thermal transfer printer. As the printing speed of the thermal transfer printer increases, the energy applied per unit time by the thermal head at the time of printing becomes higher. The amount of heat received by the sheet is higher than before. Further, during normal printing, tension is applied to the thermal transfer sheet in the flow direction. Therefore, the thermal energy and tension at the time of printing cause elongation of the base sheet of the thermal transfer sheet, resulting in deformation of the thermal transfer sheet such as wrinkles. There is a problem that the sheet cannot be conveyed and printing becomes impossible. In addition, the thermal energy at the time of printing described above is particularly high when the recording is performed using a sublimation type thermal transfer sheet, due to the difference in the recording method, compared with the case of recording with a heat melting type thermal transfer sheet. It has been.

  When performing high-density or high-speed printing with a conventional thermal transfer sheet, if the high temperature above the melting point of plastic is applied to the plastic film of the base sheet, the base sheet loses heat and the thermal transfer sheet As a result, wrinkles are generated, and as a result, image unevenness due to the wrinkles occurs in the printed image. In order to prevent wrinkles from occurring in such a thermal transfer sheet, it has been proposed to form a layer (heat resistant slipping layer) containing various heat resistant resins on the surface opposite to the thermal transfer color material layer surface of the base sheet. .

  For example, Patent Document 1 describes that a heat-resistant slip layer of a thermal transfer sheet is crosslinked with a heat-crosslinkable polymer that is a heat-resistant resin to improve heat resistance. Further, Patent Document 2 describes that the heat resistance is improved by crosslinking an electron beam crosslinkable polymer, which is a heat resistant resin, on the heat resistant slipping layer of the thermal transfer sheet. Patent Document 3 describes that the heat-resistant slip layer of the thermal transfer sheet is crosslinked with an ultraviolet-crosslinkable polymer that is a heat-resistant resin to improve heat resistance.

  However, in these methods, if the layer thickness is increased in order to obtain the desired performance, a large amount of energy is required to cure the heat-resistant resin. As a result, the base sheet of the thermal transfer sheet is heated. There was a problem that deformation occurred. In addition, it has been proposed to add a lubricant such as silicone oil, low melting point WAX, and surfactant to improve the slip property (slip property) between the back side of the thermal transfer sheet and the thermal head. When these lubricants are 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 particular, when thermal transfer recording is performed in a long run in order to obtain a large number of printed materials, there is a problem in that debris adheres to and accumulates on the thermal head and affects the image quality of the printed material.

  Further, if a heat-resistant slipping layer containing a resin cured with isocyanate and an inorganic filler such as silica is used, even if the thermal head residue is attached, the residue can be removed. There is a problem that the heat-resistant slipping layer in contact with the magnetic head is very hard, the amount of wear of the thermal head is increased, and the life of the thermal head is shortened.

JP-A-6-278373 JP-A-6-171248 Japanese Patent Laid-Open No. 2-128899

  As described above, under the high-speed printing conditions, wrinkles are generated on the thermal transfer sheet, and adverse effects such as accumulation of debris on the thermal head are likely to occur. A thermal transfer sheet with a heat transferable colorant layer and a heat resistant slipping layer on the other side has good slipperiness between the heat resistant slipping layer and the thermal head, and wrinkles are generated on the thermal transfer sheet during printing. It is another object of the present invention to provide a thermal transfer sheet having heat resistance that prevents the residue from being easily deposited on the thermal head and the thermal head from being easily worn.

  The above object is achieved by the present invention described below. That is, the present invention has a dye layer as an essential component on one surface of the base sheet, and further forms a heat-meltable colored ink layer and / or a heat transferable protective layer in the surface order, and the other side of the base sheet. In the thermal transfer sheet in which the heat-resistant slip layer is formed on the surface, two types of the heat-resistant slip layer are separately applied, and the base sheet at a position where one type of the heat-resistant slip layer A is exposed on the surface The dye layer is provided on the opposite side, and the heat-meltable colored ink layer and / or the heat-transferable protective layer is provided on the opposite side of the base sheet where the other heat-resistant slip layer B is exposed on the surface. The heat resistant slipping layer A contains a lubricant in a non-curable resin, and the heat resistant slipping layer B contains a filler in a curable resin.

  By adopting the above configuration, the dye layer in the thermal transfer sheet is a configuration in which the heat-resistant slipping layer A does not contain a curable resin and contains a lubricant in a non-curable resin even when high heat is applied in high-speed printing. It is flexible, and it is difficult for wrinkles to occur on the thermal transfer sheet at the time of printing, and further, it is difficult to wear the thermal head. On the other hand, in the heat resistant slipping layer A, debris is likely to be deposited on the thermal head. However, in order to obtain a large number of printed products, when thermal transfer recording is performed with a long run, the debris adheres to the thermal head. A large amount of debris accumulates and tends to affect the image quality of the printed matter. On the other hand, since the heat-resistant slip layer of the thermal transfer sheet to be used has the heat-resistant slip layer A and the heat-resistant slip layer B for each screen unit of the printed matter, the thermal head residue is attached to the heat-resistant slip layer B. And you can clean it. That is, when a dye is transferred from a dye layer to a thermal transfer image-receiving sheet to form a thermal transfer image for one screen, there is residue attached to the thermal head, but a heat-resistant slipping layer mainly composed of a curable resin. When transferring the heat-meltable colored ink layer and / or the heat-transferable protective layer at the position B, the thermal head residue can be frequently cleaned on a screen-by-screen basis with the heat-resistant slipping layer B. As a result, a print with excellent image quality can be formed. However, in the heat resistant slipping layer B, wear of the thermal head is likely to occur, but the heat resistant slipping layer A and the heat resistant slipping layer B which are difficult to wear the thermal head are separately applied on the back side of the thermal transfer sheet. Since the heat-resistant slip layer B is not always in contact with the thermal head, there is no problem.

  The curable resin in the heat resistant slipping layer B is a resin curable with isocyanate or chelate, and the non-curable resin of the heat resistant slipping layer A contains a curable resin curable with isocyanate or chelate. It is preferable that the main component is a thermoplastic resin. Thereby, the heat-resistant slipping layer B by the thermosetting crosslinked material can be formed stably by heating.

  The heat-resistant slip layer B is provided on the entire back surface of the base sheet, and the heat-resistant slip layer A is formed on the opposite side of the base sheet in the region where the dye layer is provided. Preferably, it is provided above. As a result, the heat-resistant slipping layer A and the heat-resistant slipping layer B can be separately coated by matching the formation position of the heat-resistant slipping layer A. As a result, the heat-resistant slipping layer B can be separately coated. Manufacturing is efficient.

  In the thermal transfer sheet of the present invention, in the dye layer in the thermal transfer sheet, even when high heat in high-speed printing is applied by a thermal head, the heat-resistant slipping layer A does not contain a curable resin, and the non-curable resin contains a lubricant. It is flexible and does not easily wrinkle the thermal transfer sheet during printing. On the other hand, the heat resistant slipping layer A has a defect that debris is easily deposited on the thermal head, but the heat resistant slipping layer B can compensate for the defect. That is, when the heat-meltable colored ink layer and / or the heat-transferable protective layer is transferred at the position of the heat-resistant slip layer B mainly composed of a curable resin, the thermal head residue is transferred to the heat-resistant slip layer B. Can be cleaned. However, although the heat-resistant slip layer B has a defect that the thermal head is likely to be worn, the heat-resistant slip layer A and the heat-resistant slip layer B that are difficult to wear the thermal head are separately applied on the back side of the thermal transfer sheet. Therefore, there is no problem in practical use.

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.

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. On one surface of the base sheet 1, as the heat-resistant slip layer 2, the heat-resistant slip layer A (21) and the heat-resistant slip layer B (22) are separately formed to form the heat-resistant slip layer A. The dye layer 3 is provided on the opposite side of the base sheet 1 at the position, and the thermal transfer protective layer 4 is provided on the opposite side of the base sheet 1 at the position where the heat-resistant slip layer B is formed. As the layer 3, a yellow dye layer 31, a magenta dye layer 32, a cyan dye layer 33, and a thermal transferable protective layer 4 are repeatedly provided in the surface direction in the flow direction of the base sheet 1.

  FIG. 2 shows another embodiment which is a thermal transfer sheet of the present invention. On one surface of the base sheet 1, a yellow dye layer 31, a magenta dye layer 32, a cyan dye layer 33, a heat-meltable black ink layer 5, and a heat transferable protective layer 4 are formed on the base sheet 1 as the dye layer 3. In the flow direction, repeatedly provided in the surface order, the heat-resistant slip layer B (22) is provided on the entire surface of the other surface of the base sheet 1 as the heat-resistant slip layer 2 in contact with the base sheet 1. On the opposite side of the base material sheet 1 in the region where the dye layer 3 is provided, the heat-resistant slip layer A (21) is partially provided on the heat-resistant slip layer B (22). Thus, the dye layer 3 is provided on the opposite side of the base sheet 1 at the position where the heat-resistant slip layer A (21) is exposed on the surface, and another heat-resistant slip layer B (22) is exposed on the surface. The heat-meltable black ink layer 5 and the heat-transferable protective layer 4 are provided on the opposite side of the base sheet 1 at the position where the heat transfer is performed. A primer layer can be provided between the base sheet and the heat-resistant slip layer, or between the base sheet and the dye layer.

Below, each layer which comprises the thermal transfer sheet of this invention is demonstrated in detail.
(Substrate sheet)
The substrate sheet 1 constituting the thermal transfer sheet of the present invention may be any material as long as it has a conventionally known degree of heat resistance and strength, for example, 0.5 to 50 μm, preferably about 3 to 10 μm. Polyethylene terephthalate film, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, In addition to cellulose derivatives such as cellulose acetate, polyethylene films, polyvinyl chloride films, nylon films, polyimide films, ionomer films, and other resin films Further, it may be paper such as condenser paper or paraffin paper, nonwoven fabric, or a composite of paper or nonwoven fabric and resin.

(Heat resistant slipping layer)
The heat-resistant slip layer 2 is formed for the purpose of improving the runnability, heat resistance, etc. of the thermal head during printing. In the present invention, the heat-resistant slip layer is a heat-resistant slip layer A which is two types of layers. And the heat-resistant slip layer B are coated on the base sheet. The heat-resistant slipping layer A does not contain a curable resin, and has a constitution in which a non-curable resin contains a lubricant, is flexible, and heat-transfers the dye from the dye layer of the thermal transfer sheet to the thermal transfer image-receiving sheet for printing. Prevents thermal transfer sheet from wrinkling. The heat-resistant slip layer B has a configuration in which a filler is contained in the curable resin, and can solve the disadvantage that debris is likely to be deposited on the thermal head of the heat-resistant slip layer A. That is, when transferring the heat-meltable colored ink layer and / or the heat-transferable protective layer at the position of the heat-resistant slip layer B, the thermal head residue can be cleaned with the heat-resistant slip layer B. Since the curable resin itself constituting the heat resistant slipping layer B has high heat resistance and is not significantly damaged by heating (it does not become a residue), the curable resin itself has the above cleaning effect. Moreover, a cleaning effect can be given more by containing a hard filler with a shot-type abrasion degree of 15-100 mg.

  The binder resin that forms the heat-resistant slip layer A is a non-curable resin and is a thermoplastic resin. However, although it is not a thermosetting resin, a relatively high polymer having a glass transition temperature of 70 to 150 ° C. is used in order to provide heat resistance. As a preferable thermoplastic resin, known resins can be used, for example, polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylate resins, polyacrylamide resins. , Polyamide resins, polyether resins, polystyrene resins, polyethylene resins, polypropylene resins, polyolefin resins, vinyl resins such as polyvinyl chloride resins and polyvinyl alcohol resins, cellulose resins, hydroxyethyl cellulose resins, cellulose acetate resins And cellulose-based resins such as polyvinyl acetoacetal resins and polyvinyl butyral resins, silicone-modified resins, and long-chain alkyl-modified resins.

  Examples of the lubricant contained in the heat resistant slipping layer A include phosphate ester surfactants, dimethylpolysiloxane, methylphenylpolysiloxane, polyethylene wax, montan wax, fatty acid amide, fatty acid ester, and polyvalent metal of alkyl phosphate ester. Salts, metal soaps such as metal salts of alkyl carboxylic acids, long chain aliphatic compounds, low molecular weight polypropylene, block copolymers of ethylene oxide and propylene oxide, condensates of fatty acid salts and polyether compounds, perfluoroalkyl ethylene oxide One or a mixture of two or more of an adduct, a long-chain alkylsulfonic acid sodium salt, a sorbitan acid ester compound, a higher alcohol and / or a reaction product of a higher amine and an isocyanate can be used.

  The amount of the lubricant added is in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight, based on 100 parts by weight of the binder resin. When the addition amount of the lubricant is less than 1 part by mass in the above, sufficient slidability with respect to the thermal head is not obtained, and the thermal transfer sheet sticks to the thermal head, and print wrinkles are generated. On the other hand, when the addition amount of the lubricant exceeds 100 parts by mass in the above, when the thermal transfer sheet is wound and stored, the lubricant of the heat resistant slipping layer moves to the overlapping heat transferable colorant layer, and the heat transferable colorant layer In the case of a dye layer using a sublimable dye, the dye easily moves to the heat-resistant slipping layer. When this is used for printing, debris adheres to the thermal head. The color reproducibility of the image will also be adversely affected.

  Further, it is preferable to further improve the slipperiness by adding a filler to the heat resistant slippery layer A. The filler has a shot-type wear degree of 15 to 100 mg, more preferably 20 to 40 mg. If the degree of wear is lower than 15 mg, the particles are too soft and are crushed by heat and pressure during printing, and head scum and sticking are likely to occur. If the degree of wear is higher than 100 mg, head wear resistance is deteriorated. The above-mentioned shot-type wear level refers to the amount of wear due to shot wear by weighing the powder to be measured together with water and shot into a measuring glass tube and rotating the specified number of revolutions. It is a method of defining the degree. However, the shot used here is a lead ball shot (2A) defined by the JIS standard.

  Examples of the filler (particle) 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 silica. Inorganic particles such as oxides such as graphite, graphite, boron nitride, etc., or organic resin particles composed of acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, polystyrene resin, nylon resin, etc. Or crosslinked resin fine particles obtained by reacting these with a crosslinking agent. The particles as described above are desirably used at a ratio of 5 to 40 parts by mass with respect to 100 parts by mass of the binder resin. If the addition amount is too small, the slipperiness is insufficient, while if it is too much, the heat resistance formed. The flexibility and film strength of the slipping layer are reduced.

  The binder resin that forms the heat-resistant slip layer B is a curable resin, and examples thereof include a polyol resin that is a compound containing two or more hydroxyl groups (OH), and is crosslinked by adding a crosslinking agent. The polyol resin contained in the heat-resistant slip layer B is not particularly limited, and examples thereof include a polyvinyl acetal resin, a polyvinyl acetoacetal resin, a polyester resin, a polyacrylate resin, a polyurethane resin, and a polyacrylate. Resin, polyamide resin, polycarbonate resin, polyether resin, and cellulose resin. Among these, cellulose resins such as cellulose acetate propionate or polyvinyl acetal resins such as polyvinyl butyral are preferable in terms of high molecular weight and hydroxyl value.

  Examples of the cellulose-based resin include CAB553-0.4 (manufactured by Eastman Chemical Co., Ltd.) and CAP482-0.5 (manufactured by Eastman Chemical Co., Ltd.). Examples of the polyvinyl acetal-based resin include BX-1 (manufactured by Sekisui Chemical Co., Ltd.). , BM-1 (manufactured by Sekisui Chemical Co., Ltd.) and the like can be suitably used. The blending amount of the polyol resin is preferably 30 to 90% by mass and more preferably 50 to 80% by mass with respect to the total solid content of the heat resistant slipping layer. Further, the hydroxyl value of the polyol resin is preferably 5 to 100 KOHmg / g, and more preferably 10 to 80 KOHmg / g. The number average molecular weight (measured by size exclusion chromatography) is preferably from 1,000 to 200,000, and more preferably from 10,000 to 100,000. When the blending amount, the hydroxyl value, and the number average molecular weight of the polyol resin are in the above ranges, handling as a material is easy, and a coating film having good strength and flexibility can be formed.

  Examples of the crosslinking agent contained in the heat resistant slipping layer B include polyisocyanate, and various types are conventionally known. Of these, it is desirable to use an adduct of 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 (isocyanatophenyl) 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.

  These polyisocyanates include, for example, Takenate (manufactured by Takeda Pharmaceutical Co., Ltd.), Barnock (manufactured by Dainippon Ink and Chemicals Co., Ltd.), Coronate (manufactured by Nippon Polyurethane Industry Co., Ltd.), Duranate (manufactured by Asahi Kasei Kogyo Co., Ltd.), Dismodule It can be obtained under a trade name such as (manufactured by Bayer) and used in the present invention. The addition amount of the polyisocyanate is suitably in the range of 5 to 200 parts by mass with respect to 100 parts by mass of the binder resin constituting the heat resistant slipping layer. The -NCO / -OH ratio is preferably in the range of 0.6 to 2.0. 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 may remain in the slipping layer and cause problems such as reaction with moisture in the atmosphere. In addition, as a hardening | curing agent of binder resin which has reactive groups, such as a hydroxyl group, not only said polyisocyanate but a chelate compound, carbodiimide, etc. can also be used.

  As the filler contained in the heat resistant slipping layer B, the same kind as that described in the heat resistant slipping layer A can be used. Among them, a hard filler having a shot-type wear degree of about 100 to 160 mg is used. The residue deposited on the thermal head can be cleaned by printing with the slipping layer A. Moreover, a slip agent with a thermal head can be improved by making the heat resistant slipping layer B contain a lubricant. As the lubricant contained in the heat resistant slipping layer B, those described in the lubricant contained in the heat resistant slipping layer A can be used in the same manner.

  In order to provide the heat-resistant slip layer A and the heat-resistant slip layer B on the base sheet, the necessary components are dissolved or dispersed in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene and the like. As a layer forming ink, this is formed on a base sheet by a conventional appropriate printing method such as gravure coater, roll coater, wire bar, and coating method. It is then dried by heating to a temperature between 30 ° C and 80 ° C. In the case of the heat resistant slipping layer B, the heat resistant slipping layer may be formed by reacting a binder resin having a reactive group such as a hydroxyl group with a curing agent. The thickness of the heat-resistant slip layers A and B is 0.5 to 5 μm, preferably 1 to 2 μm. When the film thickness is less than 0.5 μm, the effect as the heat resistant slipping layer is not sufficient, and when it is thicker than 5 μm, heat transfer from the thermal head to the dye layer is deteriorated and the print density is lowered. When a heat resistant slipping layer is provided on the base sheet, it is preferable to heat the heat resistant slipping layer B in order to promote the reaction between the binder resin having a reactive group such as a hydroxyl group and the curing agent. In order to prevent the layer from being affected by heat, it is preferable to provide a dye layer, a thermal transfer protective layer, and a heat-meltable colored ink layer after providing a heat-resistant slipping layer on the base sheet.

  When the heat-resistant slipping layer A and the heat-resistant slipping layer B are separately applied on the base sheet in the arrangement shown in FIG. 1, for example, carbon black or a fluorescent color former is applied to the coating solution of the heat-resistant slipping layer A. The heat-resistant slipping layer A is first applied to the base sheet, the heat-resistant slipping layer A is applied to the gravure plate, and the heat-resistant slipping layer B is applied to form a pattern. Layer A is printed intermittently. Next, using a detector (sensor) capable of reading the carbon black and fluorescence color of the printed heat resistant slipping layer A, the printed head and end portions of the heat resistant slipping layer A are detected. Then, the position of the heat-resistant slip layer B is aligned with the portion adjacent to the heat-resistant slip layer A, and printing is applied. At that time, even in the printing of the heat resistant slipping layer B, the heat resistant slipping layer B is formed on the gravure plate to be used, and the heat resistant slipping layer B is formed into a pattern with a space between the heat resistant slipping layer A applied. Print intermittently. In the arrangement of FIG. 1, after coating the heat-resistant slipping layer separately, when applying the dye layer and the heat transferable protective layer, the carbon black and the fluorescent color former contained in the heat-resistant slipping layer A are used with a sensor. By detecting, the printing positions of the yellow, magenta, and cyan dye layers can be matched, and the printing position of the heat transferable protective layer can also be matched by detecting the heat-resistant slipping layer A in the same manner.

  In the case of the arrangement shown in FIG. 2, the heat-resistant slip layer B is first formed on the entire surface of the base sheet, and then the heat-resistant slip is applied with a coating liquid to which carbon black or a fluorescent color former is added. The conductive layer A is formed. As the gravure plate for printing the heat-resistant slipping layer A, a patterned one is used with a space formed between the heat-meltable black ink layer and the heat-transferable protective layer. After that, when coating the dye layer, the heat-meltable black ink layer, and the heat-transferable protective layer in the arrangement shown in FIG. 2, the carbon black and the fluorescent color former contained in the heat-resistant slip layer A are used with a sensor. Detect and align the printing positions of the yellow, magenta, and cyan dye layers, and also match the printing positions of the heat-meltable black ink layer and the heat transferable protective layer by detecting the heat-resistant slip layer A in the same manner. Can do.

(Dye layer)
The dye layer 3 formed on the other surface of the base sheet on which the heat-resistant slip layer A is provided is a layer containing a sublimable dye. As the sublimation dye, any dye conventionally used in known thermal transfer sheets can be used in the present invention and is not particularly limited. These dyes include methine series such as diarylmethane series, triarylmethane series, thiazole series, merocyanine, indoaniline series, azomethine series such as acetophenone azomethine, pyrazoloazomethine, imidazolazomethine, pyridone azomethine, xanthene series, oxazine series. 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, 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, a release agent, etc.), fillers, and the like as necessary to one surface of the base sheet. 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.

(Hot-melting colored ink layer)
The heat-meltable colored ink layer 5 formed on the other surface of the base sheet on which the heat-resistant slip layer B is provided is formed from the following heat-meltable colored ink. The heat-meltable colored ink used in the present invention comprises a colorant and a vehicle, and various additives are added as necessary. As the colorant, among organic or inorganic pigments or dyes, those having a color density required as a recording material and not discolored by light, heat, temperature or the like are preferable. In addition, a substance that develops color when heated or a substance that develops color when brought into contact with a substance applied to the transfer medium can also be used. In addition to cyan, magenta, yellow, black and the like, various colorants can be used as the colorant.

  The vehicle is mainly composed of a wax, and in addition, a mixture of a wax and a drying oil, resin, mineral oil, cellulose, rubber derivatives, or the like is used. In addition, the heat-meltable colored ink layer made of heat-meltable colored ink can contain a heat conductive material in order to give good heat conductivity and melt transferability. Examples of such a heat conductive material include carbonaceous materials such as carbon black, aluminum, copper, tin oxide, and molybdenum disulfide. As a method of forming a heat-meltable colored ink layer on a substrate sheet using the above-mentioned heat-meltable colored ink, known methods such as hot melt coating, hot lacquer coating, gravure coating, gravure reverse coating, roll coating, etc. A method is mentioned. The thickness of the heat-meltable colored ink layer made of heat-meltable colored ink can be appropriately determined in consideration of the required printing density, heat sensitivity, etc., and is usually about 0.1 to 30 μm.

(Thermal transfer protective layer)
As the protective layer forming material and forming method of the thermal transferable protective layer 4 in the present invention, various materials conventionally known as protective layer forming resins can be used. Examples of resins for forming the protective layer include polyester resins, polystyrene resins, acrylic resins, polyurethane resins, acrylic urethane resins, resins obtained by modifying these resins with silicone, mixtures of these resins, and ionizing radiation curable resins. It can be illustrated. The above resin is dissolved in a solvent to prepare a coating solution, and the coating solution is applied and dried to form a heat transferable protective layer. The thickness of the protective layer is about 0.5 μm to 10 μm.

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
A gravure coater is used on one surface of a base sheet of a polyethylene terephthalate film having a thickness of 6 μm that has been subjected to easy adhesion treatment, and the following coating solution 1 for heat-resistant slipping layer 1 is 1.0 g / m ^{2 in} terms of solid content. Then, the heat resistant slipping layer A was formed by applying and drying in a pattern in the arrangement as shown in FIG.

<Coating liquid 1 for heat resistant slipping layer A>
・ Acrylic resin 65 parts (Dianar BR-80, manufactured by Mitsubishi Rayon Co., Ltd.)
・ 5 parts of talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 10 parts of zinc stearyl phosphate (refined LBT1830, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 10 parts of zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.)
-Polyethylene wax 10 parts (Polywax TM 1000, manufactured by Baker Petrolite)
・ Fluorescent whitening agent 1 part (UVITEX OB, manufactured by Ciba Japan Co., Ltd.)
・ Methyl ethyl ketone 400.0 parts ・ Toluene 400.0 parts

Further, as shown in FIG. 1, a gravure coater is used for the uncoated portion of the heat resistant slipping layer A, and the following heat resistant slipping layer B coating liquid 1 is converted to 1.0 g / m ^{2 in} terms of solid content. The heat resistant slipping layer B was formed by coating and drying in a pattern at a ratio of However, the fluorescent whitening agent contained in the heat resistant slipping layer A was detected by a sensor, and the position of the heat resistant slipping layer B was aligned so as to be arranged as shown in FIG.
<Coating liquid 1 for heat-resistant slip layer B>
・ 30 parts of polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
110 parts of polyisocyanate (Bernock D750-45, solid content 45% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Phosphate surfactant 15 parts (Pricesurf A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.)
・ Talc (Microace L-3, manufactured by Nippon Talc Kogyo Co., Ltd.) 5 parts ・ Methyl ethyl ketone 400.0 parts ・ Toluene 400.0 parts

On the other side of the base sheet (on the easy-adhesion treated side), a gravure coater, using the following coating liquid, yellow dye layer (Y), magenta dye layer (M), cyan dye layer (C), It was formed in this order by repeating the surface sequence. However, each dye layer was formed under the region where the heat-resistant slip layer A was applied, as shown in FIG. The fluorescent whitening agent contained in the heat resistant slipping layer A was detected by a sensor, and the printing positions of the yellow, magenta and cyan dye layers were adjusted. Each dye layer (Y, M, C) was applied and dried at a rate of 1.0 g / m ^{2 in} terms of solid content, using the following coating solution for each dye layer (Y, M, C). .

<Yellow dye layer coating liquid (Y)>
Disperse dye (holon brilliant yellow-S-6GL) 5.5 parts Binder resin 4.5 parts (polyvinyl acetoacetal resin KS-5, manufactured by Sekisui Chemical Co., Ltd.)
・ Phosphate 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 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 (Kayaset Blue 714) 4.5 parts-Binder resin (polyvinylacetoacetal resin KS-5, manufactured by Sekisui Chemical Co., Ltd.) 4.5 parts-Phosphate ester surfactant 0.1 parts ( Price Surf A208N (Daiichi Pharmaceutical Co., Ltd.)
・ Polyethylene wax 0.1 part ・ Methyl ethyl ketone 45.0 parts ・ Toluene 45.0 parts

A ratio of 1.0 g / m ^{2 in} terms of solid content using the following coating solution for a heat transferable protective layer as shown in FIG. Was applied and dried to form a heat transferable protective layer, and a heat transfer sheet of Example 1 was produced. However, between the thermal transferable protective layer and the base sheet, using the following release layer coating solution, it was coated and dried at a rate of 1.0 g / m ^{2 in} terms of solid content, A release layer was formed. The release layer and the heat transferable protective layer were printed by aligning the fluorescent whitening agent contained in the heat resistant slipping layer A by detecting it with a sensor.
<Coating liquid for thermal transfer protective layer>
・ 100.0 parts of vinyl chloride-vinyl acetate copolymer resin (Solvine CNL Nissin Chemical Industry Co., Ltd.)
・ Toluene 150.0 parts ・ Methyl ethyl ketone 150.0 parts

<Release layer coating solution>
・ Urethane resin (Chrisbon 9004, manufactured by DIC) 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

(Example 2)
Using a gravure coater on one surface of a 6 μm thick easily adhesive-treated polyethylene terephthalate film base sheet, 1.0 g of B coating liquid 1 for heat resistant slipping layer used in Example 1 in terms of solid content is used. The heat resistant slipping layer B was formed by coating and drying the entire surface of the base material sheet at a ratio of / m ² . Further, in the arrangement as shown in FIG. 2, the heat-resistant slip layer A coating solution 1 used in Example 1 is 1.0 g / m ^{2 in} terms of solid content on the heat-resistant slip layer B. The heat resistant slipping layer A was formed by coating and drying in a ratio.

Using the yellow, magenta, and cyan coating liquids used in Example 1 by a gravure coater on the other side of the base sheet (on the easy adhesion treatment side), a yellow dye layer (Y), a magenta dye layer (M) and the cyan dye layer (C) were repeatedly formed in this order in the surface order. However, each dye layer was formed under the region where the heat resistant slipping layer A was applied, as shown in FIG. The fluorescent whitening agent contained in the heat resistant slipping layer A was detected by a sensor, and the printing positions of the yellow, magenta and cyan dye layers were adjusted. Each dye layer (Y, M, C) was applied and dried at a rate of 1.0 g / m ^{2 in} terms of solid content, using each dye layer (Y, M, C) coating solution.

As shown in FIG. 2, the following heat-meltable black ink is applied to the remaining part of the base sheet on which each dye layer is formed, and applied at a rate of 1.0 g / m ^{2 in} terms of solid content. It dried and formed the heat-meltable black ink layer. The hot-melt black ink layer was printed by aligning the fluorescent whitening agent contained in the heat-resistant slip layer A with a sensor.
<Heat-meltable black ink>
・ 20.0 parts of vinyl chloride-vinyl acetate copolymer resin solution (Solvine CNL manufactured by Nissin Chemical Industry Co., Ltd.)
Carbon black 10.0 parts Methyl ethyl ketone / toluene (mass ratio 1/1) 70.0 parts

As shown in FIG. 2, the release layer coating liquid used in Example 1 is used as the solid content in the remaining portions where the above dye layers and the heat-meltable black ink layer are formed. Coating, drying and forming at a rate of 1.0 g / m ^{2 in} terms of conversion, and using the coating solution for the heat transferable protective layer used in Example 1 on the release layer, the solid content conversion Was applied and dried at a rate of 1.0 g / m ² to form a thermal transferable protective layer, and a thermal transfer sheet of Example 2 was produced. The release layer and the heat transferable protective layer were printed by aligning the fluorescent brightening agent contained in the heat resistant slipping layer A with a sensor.

(Example 3)
In the thermal transfer sheet produced in Example 1, only the coating solution for the heat resistant slipping layer A was changed as follows, and the thermal transfer sheet of Example 3 was produced in the same manner as in Example 1.
<Coating fluid 2 for heat resistant slipping layer A>
・ 65 parts of polyvinyl butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
・ 5 parts of talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 10 parts of zinc stearyl phosphate (refined LBT1830, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 10 parts of zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.)
-Polyethylene wax 10 parts (Polywax TM 1000, manufactured by Baker Petrolite)
・ Fluorescent whitening agent 1 part (UVITEX OB, manufactured by Ciba Japan Co., Ltd.)
・ Methyl ethyl ketone 400.0 parts ・ Toluene 400.0 parts

Example 4
In the thermal transfer sheet produced in Example 1, only the coating solution for the heat resistant slipping layer A was changed as follows, and the thermal transfer sheet of Example 4 was produced in the same manner as in Example 1.
<Coating fluid 3 for heat resistant slipping layer A>
・ 65 parts of polyester urethane resin (Byron UR-3200, manufactured by Toyobo Co., Ltd.)
・ 5 parts of talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 10 parts of zinc stearyl phosphate (refined LBT1830, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 10 parts of zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.)
-Polyethylene wax 10 parts (Polywax TM 1000, manufactured by Baker Petrolite)
・ Fluorescent whitening agent 1 part (UVITEX OB, manufactured by Ciba Japan Co., Ltd.)
・ Methyl ethyl ketone 400.0 parts ・ Toluene 400.0 parts

(Example 5)
In the thermal transfer sheet produced in Example 1, only the coating solution for the heat resistant slipping layer A was changed as follows, and the thermal transfer sheet of Example 5 was produced in the same manner as in Example 1.
<Coating fluid 4 for heat resistant slipping layer A>
・ 65 parts of polyamide-imide resin (Vilomax HR-15ET, manufactured by Sekisui Chemical Co., Ltd.)
・ 5 parts of talc (Microace P-3, manufactured by Nippon Talc Industry Co., Ltd.) 10 parts of zinc stearyl phosphate (refined LBT1830, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 10 parts of zinc stearate (SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.)
-Polyethylene wax 10 parts (Polywax TM 1000, manufactured by Baker Petrolite)
・ Fluorescent whitening agent 1 part (UVITEX OB, manufactured by Ciba Japan Co., Ltd.)
・ Methyl ethyl ketone 400.0 parts ・ Toluene 400.0 parts

(Comparative Example 1)
In the thermal transfer sheet produced in Example 1, the heat resistant slipping layer is not separately applied to the two types of layers, but the heat resistant slipping layer A coating liquid 1 used in Example 1 is used to The heat resistant slipping layer A was formed on the entire surface of one surface by coating and drying. No other heat-resistant slip layer was provided. The other dye layer and the heat transferable protective layer were formed in the same manner as in Example 1 to produce a heat transfer sheet of Comparative Example 1.

(Comparative Example 2)
In the heat transfer sheet produced in Example 1, the heat-resistant slipping layer is not separately applied to the two types of layers, but using the coating solution 1 for the heat-resistant slipping layer B used in Example 1, The heat resistant slipping layer B was formed on the entire surface of one surface by coating and drying. No other heat-resistant slip layer was provided. The other dye layer and the heat transferable protective layer were formed in the same manner as in Example 1 to prepare a heat transfer sheet of Comparative Example 2.

The thermal transfer sheets of each of the above Examples and Comparative Examples were evaluated for printing wrinkles, thermal head residue, and thermal head durability. The evaluation method will be described below.
Evaluation method 1. Printing Wrinkles The thermal transfer sheet produced in each example was printed under the following printing conditions using the transfer target shown below, and the state of the printing wrinkles was evaluated with the naked eye.
<Printing conditions>
Transfer object: CP8000D manufactured by Mitsubishi Electric Corporation CP8000D manufactured by Mitsubishi Electric Corporation Sublimation printer Continuous printing of 100 patterns (100 sheets) of a solid pattern and a halftone pattern, and wrinkles on the printed material I checked the image quality.
The criteria for evaluating print wrinkles are as follows.
○: No print wrinkles.
Δ: Fine print wrinkles at the edge of the printed material.
X: Print wrinkles are conspicuous on the printed material.

2. Thermal head residue Under the printing conditions when the above printing wrinkles were evaluated, in each example, 100 sheets were continuously printed, and then the thermal head was removed from the printer, and the thermal head residue was observed with a microscope. The adhesion amount of was evaluated. However, in each example, the condition is that no debris is attached to the thermal head at the time of the first printing start. Thermal head residue tends to occur at the part where the thermal transfer sheet hits both sides of the thermal transfer sheet, so the judgment was made in the thermal head where the thermal head deposits hit the both sides of the thermal transfer sheet. The case where it was generated to cover the heater line was marked as x, and the case where it was not so large as to cover the heater line was marked as ◯.

3. Thermal head durability Under the printing conditions when the above-mentioned printing wrinkles are evaluated, however, the number of continuous prints is not 100, but after printing 30000, the friction surface with the thermal transfer sheet of the thermal head The durability of the thermal head was examined using a microscope.
The criteria for evaluating the durability of the thermal head are as follows.
○: Thermal head wear is hardly confirmed.
X: Wear of the thermal head can be clearly confirmed.

Table 1 shows the evaluation results of the print wrinkles, thermal head residue, and thermal head durability.

DESCRIPTION OF SYMBOLS 1 Base material sheet 2 Heat resistant slipping layer 3 Dye layer 4 Thermal transferable protective layer 5 Heat-meltable black ink layer 21 Heat resistant slipping layer A
22 Heat-resistant slip layer B
31 Yellow dye layer 32 Magenta dye layer 33 Cyan dye layer

Claims (3)

  A dye layer is essential on one side of the base sheet, and a heat-meltable colored ink layer and / or a heat transferable protective layer is formed in the surface order, and the other side of the base sheet is heat resistant and slippery. In the thermal transfer sheet in which the layer is formed, the heat-resistant slipping layer is divided into two types of layers, and on the opposite side of the base sheet at the position where one type of heat-resistant slipping layer A is exposed on the surface, A dye layer is provided, and the heat-meltable colored ink layer and / or the heat-transferable protective layer is provided on the opposite side of the base sheet where the other heat-resistant slip layer B is exposed on the surface. The heat transfer sheet is characterized in that the conductive layer A contains a lubricant in a non-curable resin, and the heat-resistant slip layer B contains a filler in the curable resin.   The curable resin in the heat-resistant slip layer B is a resin curable with isocyanate or chelate, and the non-curable resin of the heat-resistant slip layer A contains a curable resin curable with isocyanate or chelate. The thermal transfer sheet according to claim 1, wherein the thermal transfer sheet is mainly composed of a thermoplastic resin. The heat-resistant slip layer B is provided on the entire back surface of the base sheet, and the heat-resistant slip layer A is formed on the opposite side of the base sheet in the region where the dye layer is provided. The thermal transfer sheet according to claim 1, wherein the thermal transfer sheet is provided on the top.

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