JPH0615975A - Thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To provide a thermal transfer image receiving sheet suppressed in curling after the formation of an image, showing good flatness after a photograph like image is formed and forming a good finish image having high density and free from the irregularity of image density. CONSTITUTION:A core material 3 for preventing curling is bonded to at least the single surface of a porous plastic film 2 to form a base material and a receiving layer 5 is provided to the porous plastic film of the base material to constitute a thermal transfer image receiving sheet 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet used in combination with a thermal transfer sheet.

[0002]

2. Description of the Related Art As a conventional heat transferable sheet, one in which a coating layer of saturated polyester resin or the like is provided on the surface of synthetic paper is known, and this kind of heat transferable sheet is sublimated on the surface of polyethylene terephthalate or the like. Of a thermal head or the like that is used in combination with a thermal transfer sheet provided with a thermal transfer layer composed of an organic dye and a binder, and these sheets are superposed, and heat is generated from the back side of the thermal transfer sheet by being controlled by an electric signal according to image information. Attempts have been made to form a natural color photographic tone image by transferring the sublimable dye in the thermal transfer layer to the receiving layer by heating with a dot-like heat-sensitive means.

[0003]

However, in the above-mentioned heat transferable sheet, when synthetic paper containing a resin having low heat resistance such as polyolefin resin as a resin component is used as a base material, it is brought about by heating during image formation. Distortion remains on the synthetic paper due to heat, and the heat-transferred sheet after image formation curls.

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 heat transferable sheet of the present invention is a heat transferable sheet in which a receiving layer for receiving a dye that migrates from the heat transfer sheet when heated is provided on the base material, wherein the base material is a core material. A porous plastic film is attached to at least one surface of the substrate, and a receiving layer is provided on the porous plastic film side of the base material directly or via an intermediate layer.

[0007]

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 sectional views 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.

Examples of the core material 3 in the base material 4 include cellulose fiber paper or plastic fill, and a laminate of the above cellulose fiber paper and a plastic film can be used. As the cellulose fiber paper, high-quality paper, art paper, coated paper, wallpaper,
Examples of the backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard and the like, and the plastic film include polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, methacrylate, polycarbonate and the like. Film. The core material 3 may be the above cellulose fiber paper obtained by extrusion coating a polyolefin or the like. The thickness of the core material 3 is preferably 30 to 500 μm.

Examples of the method for adhering the porous plastic film 2 and the core material 3 include pasting using a conventionally known adhesive, pasting by the 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-
Examples include vinyl acetate copolymers, emulsion adhesives such as polyvinyl acetate, water-soluble adhesives such as polyesters containing a carboxyl group, and adhesives for lamination, such as polyurethane-based and acrylic-based organic solvent solutions. Examples include adhesives such as types.

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, polyacrylic ester resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl toluene acrylate resin, etc. Those with a urethane bond. Polyurethane resin etc. Those having an amide bond. Polyamide resin (nylon). Those with a urea bond. Urea resin etc. 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, the receiving layer having the following sea-island structure may be used instead of the one formed by simply using the synthetic resin as described above. 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) polyacrylic amide, 2) various resins containing a carboxyl group, for example, polyethylene, polyvinyl acetate, etc., 3) cellulose resin, etc. 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. It is also possible to mix and use the water-soluble synthetic resin and the synthetic resin aqueous emulsion. 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 a coating method, a means such as a mill bar coating, an air knife coating, a reverse roll coating or the like can be used, and the coating amount is appropriately selected depending on 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 phosphoric acid ester-based surfactants; and release agents such as silicone oil. Silicone oil is preferred. As the silicone oil, oily ones can be used, but curable ones are 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 a reaction-cured amino-modified silicone oil and 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,
It is particularly 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 above-mentioned 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 resin layer 7 described above 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 transfer sheet 1 to a predetermined position at the time of transfer by a photoelectric tube detection device or the like and to set the image accurately so that an image can always be formed 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.

[0030]

As described above, the heat-transferable sheet of the present invention has a constitution in which the core material is adhered to the porous plastic film as the base material, so that the heat-transferable sheet is substantially contracted by the heating of the thermal head during transfer. Does not happen, and as a result,
Curling hardly occurs after the image is formed, the problem due to the curling in the conventional heat-transferred sheet is eliminated, and the heat-transferred sheet having good flatness after transfer can be obtained.

Further, since the heat transferable sheet of the present invention uses the porous plastic film as the lower layer side of the receiving layer, when an image is formed by thermal transfer, the heat energy efficiency is high due to the heat insulating effect of the fine pores, In addition, since the cushioning property is good due to the fine pores, there is an effect that the image density is high and the variation of the image does not occur, and in combination with the good flatness, the heat transferable sheet having a good finish can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a thermal transfer 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 symbols]

 1 Thermal Transfer Sheet 2 Porous Plastic Film 3 Core Material 4 Base Material 5 Receiving Layer 6 Intermediate Layer

Claims (6)

[Claims] 1. A heat transferable sheet comprising a base material and a receptive layer for receiving a dye which migrates from the heat transfer sheet when heated, wherein the base material has a porous plastic film adhered to at least one surface of a core material. And a receiving layer provided on the porous plastic film side of the substrate directly or via an intermediate layer. 2. The heat transferable sheet according to claim 1, wherein the porous plastic film is formed by stretching a synthetic resin in a state of containing a fine filler to form fine pores. 3. The heat-transferable sheet according to claim 1, wherein the core material is a cellulose fiber paper or a plastic film. 4. The heat transferable sheet according to claim 1, wherein a resin layer is provided on the side of the core material on which the porous plastic film is not adhered. 5. 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. 6. The heat-transferable sheet according to claim 1, wherein the receiving layer is provided with a release agent layer.