JP2003001952A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure good transfer of a transfer protective layer without providing a mold release layer while a close contact strength of a thermal transfer dye layer to the base sheet is held in a good state, in a thermal transfer sheet comprising the thermal transfer dye layer and the transfer protective layer in parallel on one side surface of the base sheet. SOLUTION: The thermal transfer sheet comprises the thermal transfer dye layers 2 to 4 and the transfer protective layer 5 in parallel on one side surface of the base sheet 1 in such a manner that the layers 2 to 4 are provided on the sheet 1 via a primer layer 6, and the protective layer 5 is provided directly on the sheet 1.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet used in a thermal transfer recording system such as a sublimation thermal transfer system. [0002] In a sublimation thermal transfer system, a thermal transfer sheet in which a heat transfer dye layer containing a sublimable dye is provided on the surface of a base sheet having a heat-resistant lubricating layer on the back surface is widely used. I have. When a full-color image is formed by a sublimation thermal transfer method, a thermal transfer dye layer of a thermal transfer sheet is superimposed on a material to be transferred, and heated from a back surface of the thermal transfer sheet by a thermal head according to color image information to form a large number of color dots. Although a full-color image is reproduced by transferring the image to a transfer material such as photographic paper and using the multicolored dots, there is a drawback that the resulting dye image has insufficient scratch resistance and light resistance. Therefore, in order to protect the obtained full-color image, a transparent transfer protective layer that is transferred to the printing screen after printing is provided on such a thermal transfer sheet in parallel with the thermal transfer dye layer on the base sheet of the thermal transfer sheet. Is provided. Further, as shown in FIG. 6, for a thermal transfer sheet, a base sheet 1 having a heat-resistant lubricating layer 7 formed on the back surface is used.
Is formed on one side thereof a primer layer 6 for ensuring good adhesive strength of the thermal transfer dye layers 2 to 4 to the base material sheet 1. On the primer layer 6, the thermal transfer dye layers 2 to 4 and the transfer protective layer are formed. 5 is also provided. In addition, the transfer protection layer 5
As shown in FIG. 7, a release layer 8 is formed on the primer layer 6 at a portion where the transfer protection layer 5 is to be formed, and the transfer protection layer 5 is formed on the release layer 8 as shown in FIG. Has also been done. However, in the case of the thermal transfer sheet shown in FIG. 6, since the transfer protective layer 5 is provided on the base material sheet 1 via the primer layer 6, printing is not possible. There is a problem that the transfer protection layer 5 cannot be smoothly transferred to paper. In the case of the thermal transfer sheet shown in FIG. 7,
Since the number of steps of forming the release layer 8 is increased, not only the production cost of the thermal transfer sheet is increased, but also problems such as deterioration of the coated surface and an increase in the residual solvent of the transfer protective layer 5 are caused. May adversely affect sex. An object of the present invention is to ensure good transfer of a transfer protective layer without providing a release layer, while maintaining good adhesion strength of a thermal transfer dye layer to a substrate sheet. Means for Solving the Problems The present inventors formed a primer layer between a thermal transfer dye layer and a substrate sheet, while forming a primer layer between the thermal transfer dye layer and the substrate sheet. The present inventors have found that the object of the present invention can be achieved by directly providing a transfer protective layer on a substrate sheet without forming a primer layer in the region, and have completed the present invention. That is, the present invention relates to a thermal transfer sheet in which a thermal transfer dye layer and a transfer protective layer are provided in parallel on one side of a substrate sheet, wherein the thermal transfer dye layer is provided on the substrate sheet via a primer layer. And a heat transfer sheet, wherein the transfer protection layer is provided directly on the base sheet. Hereinafter, a thermal transfer sheet of the present invention will be described in detail with reference to the drawings. The thermal transfer sheet of the present invention is shown in FIG.
As shown in FIG. 1, a primer layer 6 is provided on a base sheet 1 and thermal transfer dye layers 2 to 4 are further provided thereon, but the transfer protection layer 5 is not a primer layer 6 but a base sheet. 1 has a structure directly provided. Note that a heat-resistant lubricating layer 7 may be provided on the back surface of the base sheet 1 to prevent sticking between the thermal transfer sheet and the thermal head during thermal transfer and to ensure good running of the thermal transfer sheet. As shown in FIG. 2, the thermal transfer sheet of the present invention may be provided with a sensor mark 9 for detecting the sheet position in addition to the thermal transfer dye layers 2 to 4 and the transfer protective layer 5. . The thermal transfer dye layers 2 to 4 correspond to yellow, magenta, and cyan, however, the order of yellow, magenta, and cyan does not necessarily have to be the same. Further, as shown in FIG. 3, the thermal transfer dye layer 1 of black, not yellow, magenta or cyan, is used.
0 may be provided, and as shown in FIG. 4, thermal transfer dye layers 2 to 4 and 10 composed of four colors of yellow, magenta, cyan, and black may be formed. Further, as shown in FIG. 5, a transfer type dye receiving layer 1 for forming a dye receiving layer on plain paper so that a dye image can be formed on plain paper.
1 may be provided. As the substrate sheet 1, various conventionally known substrates can be used. For example, a polyester film, a polystyrene film, a polypropylene film,
A polysulfone film, a polycarbonate film, a polyamide film, an aramid film and the like can be used. The thickness of the base sheet 1 is not particularly limited, but is usually 1 to 30 μm, preferably 2 to 10 μm.
μm. The thermal transfer dye layers 2 to 4 and 10 are formed by dispersing a dye in a binder resin to form a film. As such a dye, various known dyes conventionally used in a thermal transfer dye layer of a thermal transfer sheet can be used. For example, as a yellow dye, an azo dye, a disazo dye, a methine dye,
Examples include styryl dyes, pyridone / azo dyes, and mixed dyes thereof. Examples of the magenta dye include an azo dye, an anthraquinone dye, a styryl dye, a double-ring type azo dye, and a mixed dye thereof. Examples of the cyan dye include anthraquinone dyes, naphthoquinone dyes, heterocyclic azo dyes, indoaniline dyes, and mixed dyes thereof. As the binder resin constituting the thermal transfer dye layers 2 to 4, and 10, various known resins conventionally used in thermal transfer dye layers of thermal transfer sheets can be used. For example, cellulose resins such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, cellulose acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetoacetal, polyvinyl acetate, vinyl resins such as polystyrene or copolymers thereof, and various urethanes Resins, polyester resins and the like. The transfer protective layer 5 is formed by forming a transparent resin into a film, and may contain various dye stabilizers and fillers as necessary. As the resin constituting the transfer protection layer 5, various known resins conventionally used in the transfer protection layer of a thermal transfer sheet can be used. It is preferable to use one exhibiting adhesiveness. For example, a cellulose acetate butyrate resin, a vinyl chloride-vinyl acetate copolymer, a polyvinyl butyral resin, a polyester resin and the like can be mentioned. The thickness of the transfer protective layer 5 can be appropriately determined according to the kind of the thermoplastic resin, the desired degree of adhesive strength, the edge cut (tailing) at the time of thermal transfer, and the like. Is preferably about 1 to 10 μm from the viewpoint of transferability. Examples of the dye stabilizer include antioxidants, ultraviolet absorbers, and light stabilizers which have been conventionally used as additives for synthetic resins. Here, as the antioxidant, a primary antioxidant such as a phenol antioxidant, a monophenol antioxidant, a bisphenol antioxidant, an amine antioxidant, or a sulfur antioxidant; And secondary antioxidants such as phosphorus antioxidants. Specifically, Sum
ilizer BBN-S, Sumilizer BH
T, Sumilizer GM, Sumilizer
MB, Sumilizer TPP-R (above, manufactured by Sumitomo Chemical Co., Ltd.), Yoshinox 425, Yoshinox SR (above, manufactured by Yoshitomi Pharmaceutical Co., Ltd.), Irganox l
081, Irganox-1222 (all manufactured by Ciba-Geigy), and Mark A0-40 (manufactured by Adeka Argus Chemical Co., Ltd.). Examples of the ultraviolet absorber include a salicylic acid ultraviolet absorber, a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, and a cyanoacrylate ultraviolet absorber. Specifically, Tinuv
in P, Tinuvin 234, Tinuvin 3
20, Tinuvin 327 (all manufactured by Ciba-Geigy), Sumisorb 110, Sumisorb
140 (manufactured by Sumitomo Chemical Co., Ltd.), Kemiso
rb 110, Kemisorb 140, Kemis
orb 12, Kemisorb 13 (manufactured by Chemipro Kasei Co., Ltd.), Uvinul X-19, Uvin
ul Ms-40 (all manufactured by BASF), Tomisorb 100, and Tomisorb 600 (all manufactured by Yoshitomi Pharmaceutical Co., Ltd.)
Manufactured), Viosorb-80, Viosorb-90
(Above, manufactured by Kyodo Yakuhin Co., Ltd.). Further, examples of the light stabilizer include a hindered amine light stabilizer. For example, specifically, SANOL LS-770, SANOL LS-765, SANOL LS774 (manufactured by Sankyo), SumisorbTM
Such as those specified by trade names such as -061 (manufactured by Sumitomo Chemical Co., Ltd.). The fillers that can be incorporated in the transfer protective layer 5 include powdery inorganic fillers such as silica, talc, clay, zeolite, titanium oxide, zinc oxide, and carbon;
A powdery organic filler made of a silicone resin, a Teflon resin, a benzoguanamine resin or the like can be used. The primer layer 6 of the thermal transfer sheet of the present invention comprises
The above-mentioned base sheet 1 and a resin showing adhesiveness to the thermal transfer dye layers 2 to 4 and 10, such as a polyester resin, an acrylic resin, and a methacrylic acid resin,
It can have the same configuration as the primer layer in the conventional thermal transfer sheet. If necessary, various curing agents may be blended. As a curing agent that can be incorporated in the primer layer, a polysocyanate compound having two or more isocyanate groups can be preferably exemplified. Specifically, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-xylene diisocyanate, hetisamethylene diisocyanate, 4,4 '
-Methylenebis (cyclohexylisocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1,3-di (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethyl
Examples thereof include hexamethylene diisocyanate and the like, and adducts of polyisocyanates in which a diisocyanate and a polyol are partially subjected to an addition reaction (polyisocyanate prepolymer; for example, agucto in which tolylene diisocyanate and trimethylolpropane are reacted). The heat-resistant lubricating layer 7 that can be used in the thermal transfer sheet of the present invention is composed of at least a resin and a lubricant, and various hardeners and fillers can be added as needed. The resin that can be used for the heat-resistant lubricating layer 7 includes
Known resins conventionally used in heat-resistant lubricating layers of thermal transfer sheets can be used, but resins having a relatively high glass transition temperature are preferred, such as polyvinyl acetal, polyvinyl butyral, phenoxy resin, acetopropyl cellulose, and the like. Can be used. As the lubricant to be incorporated into the heat-resistant lubricating layer 7, conventionally known lubricants can be used, and examples thereof include a phosphate-based lubricant and a silicone-based lubricant. As the curing agent that can be used in the heat-resistant lubricating layer 7, a polysocyanate compound having two or more isocyanate groups can be preferably exemplified. Specifically, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-xylene diisocyanate, hetisamethylene diisocyanate, 4,4 '
-Methylenebis (cyclohexylisocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1,3-di (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethyl
Examples thereof include hexamethylene diisocyanate and the like, and adducts of polyisocyanates in which a diisocyanate and a polyol are partially subjected to an addition reaction (polyisocyanate prepolymer; for example, agucto in which tolylene diisocyanate and trimethylolpropane are reacted). Examples of the filler that can be used for the heat-resistant lubricating layer 7 include powdery inorganic fillers such as silica, talc, clay, zeolite, titanium oxide, zinc oxide, and carbon;
Examples include a powdery organic filler made of a silicone resin, a Teflon (registered trademark) resin, a benzoguanamine resin, or the like. The thermal transfer sheet of the present invention is prepared by applying a primer layer-forming coating on a substrate sheet other than the portion where the transfer protective layer is to be provided by a known method such as gravure printing, drying, and curing if necessary. To form a primer layer, a thermal transfer dye layer forming paint is applied on the primer layer by a known method, dried, and cured if necessary to form a thermal transfer dye layer. It can be manufactured by applying a coating for forming a transfer protective layer to a base sheet portion where the transfer protective layer is not formed, drying, and curing as necessary to form a transfer protective layer. The thermal transfer sheet of the present invention described above can be used in the same manner as a known thermal transfer sheet in which a thermal transfer dye layer and a transfer protective layer are provided in parallel on a base sheet. The present invention will be described below in detail with reference to examples. Example 1 A 6 μm thick polyester film (Lumirror, Toray Industries, Inc.) was gravure coated with the coating composition for forming a heat-resistant lubricating layer shown in Table 1 so as to have a dry thickness of 1 μm. After drying, a heat-resistant lubricating layer was provided. As a result, a base sheet was obtained. [Table 1] Coating composition components for forming heat-resistant lubricating layer in parts by weight S-LEC KS-5 (manufactured by Sekisui Chemical Co., Ltd.) 5.0 Coronate L45E (curing agent, manufactured by Nippon Polyurethane) 2.0 Plysurf A208S ( Lubricant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. 2.5 Silica (Nipsil E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.) 0.5 Methyl ethyl ketone 45.0 Toluene 45.0 The primer layer forming paint shown in Table 2 was applied by gravure so as to have a dry thickness of 0.1 μm on the surface on which the layer was not provided, and dried and cured to form a primer layer. The paint for forming a thermal transfer dye layer 3 and the paint for forming a transfer protective layer shown in Table 4 were each coated with gravure at a predetermined position so as to have a dry thickness of 1.0 μm, and dried to produce a thermal transfer sheet. It should be noted, thermal transfer dye layer is formed on the primer layer, whereas, the transfer protective layer was formed directly on the substrate sheet. [0040] [Table 2] for forming a primer layer coating composition component parts UE3600 ( Unitika Co., Ltd. 2.0 Takenate D110N (Takeda Pharmaceutical Co., Ltd.) 0.2 Methyl ethyl ketone 48.9 Toluene 48.9 Table 3 Coating composition components for thermal transfer dye layer formation Parts by weight Dye: Disperse violet 26 0 Polyvinyl butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.) 5.0 Methyl ethyl ketone 45.0 toluene 45.0 [Table 4] Coating composition component for forming transfer protective layer Part by weight Dellepet 560F (manufactured by Asahi Kasei Corporation) 5 .0 silica (Nipsil E-200A, (manufactured by Nippon silica industrial Co., Ltd.) 1.0 Methyl ethyl ketone 47.0 toluene 47.0 [0043] Comparative Example 1 A thermal transfer sheet was obtained by repeating Example 1 except that the transfer protective layer was not provided directly on the base material sheet, but on the primer layer. A thermal transfer sheet was obtained by repeating Example 1 except that the thermal transfer dye layer and the transfer protective layer were directly provided on the base sheet without providing the thermal transfer dye layer and the transfer protective layer. Regarding the thermal transfer sheets 1 and 2, the thermal transfer dye layer of the obtained thermal transfer sheet was cut and pasted on the magenta portion of a UPC 8840 (print media for UP-D8800 manufactured by Sony Corporation) ribbon, and the obtained transfer protective layer was transferred to the transfer protective layer of the ribbon. Cut and pasted on the paper, and then print it with a UP-D8800 (a full-color printer manufactured by Sony Corporation) on a solid printing paper of UP8840 to determine whether or not the transfer protection layer has been fused and the state of the transfer. It was visually observed for the door. Table 5 shows the obtained results. [Table 5] From the results shown in Table 5, it can be seen that in the case of the thermal transfer sheet of Example 1, no fusion of the thermal transfer dye layer occurred, and the transfer protective layer was well transferred to photographic paper. On the other hand, in the case of the thermal transfer sheet of Comparative Example 1 in which the primer layer was also formed between the transfer protective layer and the base sheet, the transfer protective layer did not peel off from the base sheet and did not transfer to photographic paper. Was. Also, in the case of the thermal transfer sheet of Comparative Example 2 in which no primer layer was formed between the thermal transfer dye layer and the base sheet, it can be seen that fusion occurred in the thermal transfer dye layer. According to the thermal transfer sheet of the present invention, the thermal transfer dye layer is provided on the base sheet via the primer layer, and the transfer protective layer is provided directly on the base sheet. Good transfer of the transfer protective layer can be ensured without providing a release layer, while keeping the adhesion strength of the dye layer to the substrate sheet in a good state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a thermal transfer sheet of the present invention. FIG. 2 is a top view of an example of the thermal transfer sheet of the present invention. FIG. 3 is a top view of an example of the thermal transfer sheet of the present invention. FIG. 4 is a top view of an example of the thermal transfer sheet of the present invention. FIG. 5 is a top view of an example of the thermal transfer sheet of the present invention. FIG. 6 is a sectional view of a conventional thermal transfer sheet. FIG. 7 is a cross-sectional view of a conventional thermal transfer sheet. [Description of Signs] 1 Base sheet, 2, 3, 4, 10 Thermal transfer dye layer, 5
Transfer protection layer, 6 primer layer, 7 heat-resistant lubricating layer, 8
Release layer, 9 sensor mark, 11 transfer dye receiving layer

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Sano Motohiko             6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Soni             ー Inc. F term (reference) 2C068 AA06 AA22 BB26 BC16 BD17                       BD23                 2H111 AA33 BA02 BA03 BB06

Claims (1)

Claims: 1. A thermal transfer sheet in which a thermal transfer dye layer and a transfer protective layer are provided in parallel on one side of a substrate sheet, wherein the thermal transfer dye layer is provided on the substrate sheet via a primer layer. A heat transfer sheet, wherein the transfer protection layer is provided directly on the base sheet.