JP2686467B2 - Heat transfer sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer sheet used in combination with a heat transfer sheet. 2. Description of the Related Art As a conventional heat transferable sheet, there is known one in which a coating layer of a saturated polyester resin or the like is provided on the surface of synthetic paper, and this type of heat transferable sheet is made of polyethylene terephthalate or the like. A thermal transfer sheet that is used in combination with a thermal transfer sheet that has a thermal transfer layer consisting of a sublimable dye and a binder on the surface. Attempts have been made to form a natural color photographic image by heating a point-like heat-sensitive means such as a head to transfer the sublimable dye in the thermal transfer layer into the receiving layer. However, in the above-mentioned thermal transfer sheet, when synthetic paper containing a resin having a low heat resistance such as a polyolefin resin as a resin component is used as a base material, heating during image formation, etc. Due to the heat generated by the heat generation, the synthetic paper remains distorted and the heat-transferred sheet after image formation is curled. Further, the thermal transfer sheet using the general synthetic paper as described above has a problem that the image density is low during image formation and the image density varies. The present invention has been made in view of the above-mentioned problems, and it has a good flatness even after curling after image formation and a photographic image is formed, and has a high image density and no variation in image density. It is an object of the present invention to provide a heat-transferable sheet having good quality. [0006] That is, the present invention is a thermal transfer sheet in which a receiving layer for receiving a dye that migrates from the thermal transfer sheet when heated is provided on the substrate, wherein the substrate is a core material. A porous plastic film adhered to the core material, a receiving layer is provided on the porous plastic film side of the substrate directly or via an intermediate layer, and the core material is a plastic film or cellulose fiber paper. It is either one laminated with a plastic film or one extruded with a resin on cellulose fiber paper, wherein the porous plastic film is
The present invention is directed to a heat transferable sheet, which is characterized in that fine pores are formed by stretching a synthetic resin in a state of containing a fine filler. Embodiments of the present invention will be described with reference to the drawings. Drawing shows an example of the present invention, Drawing 1 is a longitudinal section showing one example of a heat transfer sheet of the present invention, and Drawings 2-4 are longitudinal section showing other examples of a heat transfer sheet of the present invention. . As shown in FIG. 1, the thermal transfer sheet 1 of the present invention.
Is a substrate 4 having a core material 3 attached to at least one surface of a porous plastic film 2 for preventing curling, and a receiving layer 5 provided on the porous plastic film side of the substrate 4. is there. Further, the base material 4 in the present invention has a core material 3 on one surface of the porous plastic film 2 as shown in FIG.
May be further adhered, and the porous plastic film 2 may be similarly adhered to the side of the core material 3 on which the porous plastic film is not provided. As the above-mentioned porous plastic film 2, it is possible to use a film in which fine pores are formed by stretching a synthetic resin in a state containing a fine filler. By using the porous plastic film 2, the heat-transferable sheet of the present invention has an effect that when an image is formed by thermal transfer, the image density is high and the image does not vary. This is because the heat energy efficiency is good due to the heat insulating effect of the fine pores, and the good cushioning property of the fine pores is provided on the base material and contributes to the receiving layer on which an image is formed. As the core material of the base material 4, a plastic film, a cellulose fiber paper laminated with a plastic film, or a cellulose fiber paper extrusion-coated with a resin is used. Examples of the cellulose fiber paper include high-quality paper, art paper, coated paper, wallpaper, backing paper, synthetic resin or emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin internal-addition paper, paperboard, and the like, and the plastic film described above. Examples of the rum include films of polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, methacrylate, polycarbonate and the like. The core material 3 may be the above cellulose fiber paper obtained by extrusion coating a resin such as polyolefin. The thickness of the core material 3 is 30 to 500
μ is preferred. Examples of the method for adhering the porous plastic film 2 and the core material 3 include pasting using a conventionally known adhesive, pasting using an extrusion laminating method, and pasting by heat bonding. Further, when the core material 3 is a plastic film, a lamination method and a calendering method which simultaneously serve to form the core material 3 may be used. The sticking means is appropriately selected according to the materials of the porous plastic film 2 and the core material 3. Specific examples of the adhesive include ethylene-
Emulsion adhesives such as vinyl acetate copolymers and polyvinyl acetates; water-soluble adhesives such as polyesters containing carboxyl groups; etc .; and adhesives for laminating include organic solvent solutions such as polyurethane-based and acrylic-based. An adhesive such as a type may be used. The receiving layer 5 functions to receive the sublimable dye transferred from the transfer sheet, and is provided on the substrate 4. Examples of the material of the layer 5 include the following synthetic resins. Those having an ester bond. Polyester resin, polyacrylate resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl toluene acrylate resin, etc. Those with a urethane bond. Polyurethane resin and the like. Those having an amide bond. Polyamide resin (nylon). Those with a urea bond. Urea resin and the like. Others that have highly polar bonds. Polycaprolactane resin, styrene resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, polyacrylonitrile resin, etc. In addition to the above resins, mixtures or copolymers of these can also be used. Alternatively, a receiving layer having the following sea-island structure, which is not simply constituted by using the above synthetic resin, can also be used. For example, -10
The first region of the receiving layer is formed of a synthetic resin having a glass transition temperature of 0 to 20 ° C., and the second region of the receiving layer is formed of a synthetic resin having a glass transition temperature of 40 ° C. or higher. The second area is exposed on the surface of the receiving layer 5 so that the first area is 15% or more of the surface and the first area is at the same time.
Regions are formed in islands independently of each other, and the length of each island in the longitudinal direction is preferably 0.5 to 200 μ. Any of the above-mentioned materials (1) to (3) and those having a sea-island structure may further contain an extender pigment such as silica, calcium carbonate, titanium oxide, zinc oxide, etc. be able to. As the method of forming the receiving layer 5, the above resin or the like is applied by a coating method such as air knife coating, reverse roll coating, gravure coating or wire bar coating, and dried to form. The receiving layer 5 may be directly provided on the base material 4, or may be provided on the base material 4 via the intermediate layer 6 as shown in FIG. Examples of the material of the intermediate layer 6 include saturated polyester, polyurethane, organic solvent solutions of acrylic acid ester and the like. Examples of the method for forming the intermediate layer 6 include reverse roll coating, gravure coating, wire bar coating, and the like, and the thickness of the layer 6 is preferably 3 to 15 μm. As the material for the intermediate layer 6, either an aqueous solution of a water-soluble synthetic resin or an aqueous synthetic resin emulsion may be used instead of the organic solvent solution of the synthetic resin. As the water-soluble synthetic resin, 1) polyacrylamide, 2) various resins containing a carboxyl group, for example, polyethylene, polyvinyl acetate, etc., 3) cellulose-based resin can be used. As the synthetic resin emulsion, an aqueous emulsion of synthetic resin emulsion such as polyacrylic acid ester, ethylene-vinyl acetate copolymer, polyurethane and polyester can be used. Further, the water-soluble synthetic resin and the synthetic resin aqueous emulsion can be used in combination. As a method of forming the intermediate layer 6 using a water-soluble synthetic resin or an aqueous emulsion, the above-mentioned coating means can be used, and in addition, an air knife coating method can be used. An extender pigment such as titanium oxide, zinc oxide, clay or calcium carbonate may be added to the intermediate layer 6 in order to improve the coating suitability of the coating material at the time of formation, the blocking resistance of the coating film and the hiding power. Good. The extender pigment is preferably 30 parts by weight or less with respect to 100 parts by weight of the resin solid content of the mid layer 6. In the heat transferable sheet 1 of the present invention, a resin layer 7 can be provided on the surface of the core material 3 on which the porous plastic film 2 is not provided, as shown in FIG. The resin layer 7
Mainly plays a role of preventing curling when the core material 3 is provided on only one surface of the porous plastic film 2, and also has a lubricity for facilitating taking out the heat-transferred sheets 1 one by one at the time of transfer. There is also an effect of giving. The resin layer 7 is, if necessary, a methacrylate resin such as a methyl methacrylate resin, an organic solvent solution of a vinyl chloride-vinyl acetate copolymer resin or an emulsion thereof, or a binder adder such as a synthetic rubber latex.
It can be formed by coating and drying a liquid to which a filler such as clay, calcium carbonate, silica, or titanium oxide is added. As an application method, a means such as myrbar coating, air knife coating, reverse roll coating and the like can be used, and the amount of application is appropriately selected according to the curl balance. The resin layer 7 can also be provided by extrusion coating of polyolefin or the like. In the heat transferable sheet 1 of the present invention, the antistatic layer 8 can be provided on the side of the base material 4 where the receiving layer 5 is not provided.
When the resin layer 7 is formed as shown in FIG. 5, it can be provided on the lower surface of the resin layer 7. When the resin layer is formed, the antistatic layer 8 mixes the antistatic agent in the resin forming the resin layer 7 and causes the antistatic agent to bleed on the surface of the resin layer 7, resulting in It is also possible to provide it on the resin layer 7. As the antistatic agent, a surface active agent such as a cationic surface active agent (eg, quaternary ammonium salt, polyamine derivative, etc.), an anionic surface active agent (eg, alkyl phosphate, etc.), zwitterion. Type surfactants or nonionic surfactants. The antistatic layer 8 can be formed by applying gravure coating, bar coating or the like using the above surfactant. The heat-transferable sheet 1 of the present invention may have a release agent layer 9 formed on the receiving layer 5 in order to improve the releasability from the heat transfer sheet, if necessary. For example, as shown in FIG. A release agent layer 9 can be provided on the surface of the layer 5,
Although not specifically shown, the receptive layer 5 may contain a release agent. Further, a release agent is contained in the receiving layer, and then the release agent is allowed to bleed on the surface of the receiving layer 5,
As a result, a release agent layer can be provided on the surface of the receiving layer 5. Examples of the material of the release agent layer 9 include solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphate ester-based surfactants; and release agents such as silicone oil. Silicone oil is preferred. As the silicone oil, an oily oil can be used, but a curable oil is preferable. Examples of the curable silicone oil include a reaction curable type, a photocurable type, and a catalyst curable type, and a reaction curable type silicone oil is particularly preferable. The reaction-curable silicone oil is preferably one obtained by reacting and curing an amino-modified silicone oil and an epoxy-modified silicone oil. When the releasing agent of the curable silicone oil is contained in the receiving layer 5, the addition amount thereof is preferably 0.5 to 30 wt% of the resin constituting the receiving layer 5. The thickness of the release agent layer 9 is preferably 0.01 to 5 μm,
Particularly, the thickness is preferably 0.05 to 2 μm. The heat-transferable sheet 1 of the present invention may be provided with a slipping layer for facilitating the removal of the sheets 1 one by one, if necessary. The slippery layer can be provided as the lowermost layer of the heat transferable sheet 1 so that the heat transferable sheets adjacent to each other can slip easily. The material of the slippery layer is a methacrylate resin such as methyl methacrylate or the like. Examples thereof include acrylate resins or corresponding acrylate resins, vinyl-based resins such as vinyl chloride-vinyl acetate copolymer resins, and the like.
It is formed by applying the same coating method as above and drying. (Note that the above-mentioned resin layer 7 can also function as a slipping layer.) The heat-transferable sheet 1 of the present invention is the sheet 1.
A photoelectric tube detection mark that can be detected by a photoelectric tube detection device or the like can be provided on the surface, preferably the back surface. By providing the above-mentioned mark, it is possible to align the heat-transferred sheet 1 to a predetermined position at the time of transfer by a photoelectric tube detection device or the like and accurately set it, and always form an image at an accurate desired position. ) The type such as the grade and size of the heat-transferred sheet 1 is detected, 2) the accuracy of the front and back sides when the heat-transferred sheet 1 is set is detected, 3) the direction of the heat-transferred sheet 1 is detected, and the heat-transferred sheet is transferred. There is an advantage in the work process when the transfer is actually performed using the sheet 1.
The photoelectric tube detection mark can be provided by using the same material and forming method as those of the conventionally known photoelectric tube detection mark. As described above, the heat transferable sheet of the present invention comprises a core material and a porous plastic film adhered to the core material, which is directly or directly attached to the porous plastic film. Since the receiving layer is provided via the intermediate layer, substantial thermal contraction due to heating of the thermal head during transfer does not occur, and as a result, curling does not occur after image formation, and There is an effect that the problem due to the occurrence of curling in the heat-transferred sheet is eliminated, and a heat-transferred sheet having good flatness after transfer can be obtained. Further, the heat transferable sheet of the present invention has a core material which is either a plastic film, a cellulose fiber paper laminated with a plastic film, or a cellulose fiber paper which is extrusion coated with a resin, and the core material is a porous plastic. As compared with the case where a curable resin is applied to a porous plastic film to form a cured resin coating film, the formed film is a porous film. Since there is no problem such as distortion when forming a coating film, the substrate has good flatness, and the receptive layer is provided on the substrate with good flatness, so image reproducibility is improved. Excellent in.
Further, the heat transferable sheet of the present invention is one in which the above-mentioned porous plastic film is formed with fine pores by stretching a synthetic resin in a state of containing a fine filler, and the above-mentioned porous plastic film is a foamed plastic material. Compared with a foamed plastic film formed by mixing and foaming agents, a uniform porous layer is formed,
Moreover, heat resistance and water resistance are improved by stretching, and uniformity,
Since a film having excellent physical properties such as flatness can be easily obtained, it is possible to obtain a heat transferable sheet which is more excellent in curl prevention and flatness as compared with the case where a foamed plastic film is laminated. The heat-transferable sheet of the present invention has a core material which is a plastic film, a cellulose fiber paper laminated with a plastic film, or a cellulose fiber paper which is extrusion coated with a resin. Thus, a curable curable sheet having excellent flatness can be obtained. Further, since the heat transferable sheet of the present invention uses the porous plastic film on the lower layer side of the receiving layer, when an image is formed by heat transfer, the heat energy efficiency is high due to the heat insulating effect of the fine pores, Further, since the fine pores have a good cushioning property, the image density is high, and there is an effect that the image does not fluctuate, and in combination with the good flatness described above, a heat transferable sheet having a good finish can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an example of a heat transferable sheet of the present invention. FIG. 2 is a vertical sectional view showing another example of the heat-transferable sheet of the present invention. FIG. 3 is a vertical cross-sectional view showing another example of the heat transferable sheet of the present invention. FIG. 4 is a vertical sectional view showing another example of the heat-transferable sheet of the present invention. [Explanation of Codes] 1 Heat Transfer Sheet 2 Porous Plastic Film 3 Core Material 4 Base Material 5 Receiving Layer 6 Intermediate Layer

Claims (1)

(57) [Claims] In a thermal transfer sheet having a receptive layer for receiving a dye that migrates from a thermal transfer sheet when heated, the substrate comprises a core material and a porous plastic film attached to the core material, A receiving layer is provided on the porous plastic film side of the substrate directly or via an intermediate layer, and the above core material is applied to the plastic film or cellulose fiber paper.
Laminated plastic film or cell
Extrusion coating of resin on loin fiber paper
The heat transfer sheet , wherein the porous plastic film is formed by drawing a synthetic resin in a state of containing a fine filler to form fine pores. 2. The heat transferable sheet according to claim 1, wherein a resin layer is provided on a side of the core material on which the porous plastic film is not adhered. 3. The heat-transferable sheet according to claim 1, wherein an antistatic layer is provided on the side of the base material having no receiving layer. 4. The thermal transfer sheet according to claim 1, wherein a release agent layer is provided on the receiving layer.