JPH08169186A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE: To prevent a substantial thermal contraction from occurring caused by heating of a thermal head at the time of transfer and consequently, make almost free from the generation of a curl after image formation, eliminate any trouble attributable to the curling as in a conventional thermal transfer sheet and provide excellent lubricity. CONSTITUTION: A thermal transfer sheet 1 is composed of a receptor layer 5 which receives dye immigrated from a thermal transfer medium at the time of heating, on a base material 4. In addition, the base material 4 consists of a synthetic paper 2 attached to one surface of a core material 3, and the receptor layer 5 is provided on the synthetic paper 2 side of the base material 4 directly or through an intermediate layer. At the same time, a resin layer 6 is provided on the side where the synthetic paper 2 is not attached of the core material 3.

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. It is used together with a thermal transfer sheet provided with a thermal transfer layer composed of an organic dye and a binder, and these sheets are superposed so that the thermal transfer layer and the receiving layer are in contact with each other. It has been attempted to form a natural color photographic image by transferring the sublimable dye in the thermal transfer layer to the receiving layer by heating it with a dot-like heat-sensitive means such as a thermal head controlled by a signal to generate heat. .

[0003]

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

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and uses a base material in which a core material for preventing curling is attached to synthetic paper, and the synthetic paper of the core material is attached. By providing a resin layer on the non-coated side, curling after image formation is suppressed, slipperiness is imparted, and a heat-transferable sheet having good flatness and good finish even after forming a photographic image is provided. To aim.

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 synthetic paper on one side of a core material. And a receiving layer is provided on the synthetic paper side of the base material directly or via an intermediate layer, and a resin layer is provided on the side of the core material on which the synthetic paper is not attached.

[0006]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the basic structure of the heat-transferable sheet of the present invention. The heat-transferable sheet 1 is provided with a receiving layer 5 on a base material 4 having a core material 3 provided on the lower surface of a synthetic paper 2. At the same time, the resin layer 6 is provided on the side of the core material 3 where the synthetic paper is not attached.
Is provided.

As the synthetic paper 2, any synthetic paper can be used as long as it is generally used as a synthetic paper base material for a heat transferable sheet. In particular, a synthetic paper provided with a paper-like layer containing fine pores. (For example, commercially available synthetic paper YUPO: made by Oji Yuka Synthetic Paper) is preferable. The fine pores in the paper-like layer can be formed, for example, by stretching a synthetic resin in the state of containing a fine filler. Commercially available synthetic paper YUPO is a film-type synthetic paper, and the main raw material is polypropylene resin, with inorganic filler and a small amount of additives added as raw material, and fine pores are formed by biaxially stretched film forming method. The film is formed while being generated, and has a three-layer structure of a base layer and paper-like layers formed on both front and back surfaces of the base layer. The base layer is stretched and oriented in the longitudinal and transverse directions, and both paper-like layers are transversely oriented. It is stretched and oriented only in the direction. Due to the fine pores generated in the stretching step, light is diffusely reflected and becomes white and opaque, which has a paper-like property. There are basically four grades of YUPO, depending on the above-mentioned three-layer structure and the amount of fine pores, as shown below. (1) FPG grade (standard product): Both surfaces have the same paper-like layer, high whiteness and opacity,
Both paper-like layers have many fine holes. (2) SGG grade: The paper-like layer on one side has the same number of fine pores as the FPG grade, and the paper-like layer on the other side has high surface strength and a high-gloss surface. Alternatively, those in which fine pores are not formed. (3) TPG grade: Semi-transparent on both sides of the paper-like layer with few fine pores. (4) K
PG grade: A paper-like layer with an increased surface strength, both surfaces having strong surfaces, few micropores, and slightly lower opacity than the FPG grade. In addition, thick grades with the above-mentioned (1) to (4) grades of YUPO bonded together, and grades (YUPO coat) with a special coat on the surface of the above (1) to (4) grade YUPO There is. The heat-transferable sheet formed by using the synthetic paper provided with the paper-like layer containing the fine pores has an effect that when an image is formed by thermal transfer, the image density is high and the image does not vary. It is considered that the fine pores have a heat insulating effect, the thermal energy efficiency is good, and the fine pores have a good cushioning property, which contributes to the receiving layer provided on the synthetic paper and on which an image is formed. Be done. In addition, the paper-like layer containing the fine pores is directly attached to the core material 3
It is also possible to provide it on the surface of.

The core material 3 of the base material 4 may be cellulose fiber paper or plastic film, and a laminate of the above cellulose fiber paper and plastic film may also be used. Examples of the cellulose fiber paper include high-quality paper, art paper, coated paper,
Examples include wallpaper, 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 includes polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, methacrylate, Examples of the film include polycarbonate. As the core material 3, the cellulose fiber paper obtained by extrusion coating a polyolefin or the like can be used.
Further, the thickness of the core material 3 is preferably 30 to 500 μ.

As a method for attaching the synthetic paper 2 and the core material 3,
Examples thereof include pasting using a conventionally known adhesive, pasting using an extrusion laminating method, and pasting by thermal bonding. When the core material 3 is a plastic film, the core material 3 is used.
Examples of the method include a laminating method and a calendering method, which simultaneously serve to form the above. The sticking means is appropriately selected according to the materials of the synthetic paper 2 and the core material 3. Specific examples of the adhesive include ethylene-vinyl acetate copolymer, emulsion adhesives such as polyvinyl acetate, water-soluble adhesives such as polyester containing a carboxyl group, and the like. Examples of the adhesive include organic solvent solution type adhesives such as polyurethane type and acrylic type.

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.

(A) Those having an ester bond.

Polyester resin, polyacrylic ester resin, polycarbonate resin, polyvinyl acetate resin,
Styrene acrylate resin, vinyl toluene acrylate resin, etc.

(B) Those having a urethane bond.

Polyurethane resin and the like.

(C) Those having an amide bond.

Polyamide resin (nylon).

(D) Those having a urea bond.

Urea resin and the like.

(E) Others having a highly polar bond.

Polycaprolactan resin, styrene resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, polyacrylonitrile resin and the like. In addition to the above resins, mixtures or copolymers of these can also be used.

Alternatively, the following receiving layer having a sea-island structure can be used instead of the above-mentioned synthetic resin. For example, the first region of the receiving layer is formed of a synthetic resin having a glass transition temperature of −100 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. And the second region are both exposed on the surface of the receiving layer 5, the first region is 15% or more of the surface, and at the same time, the first regions are formed into islands independently of each other. The length is preferably 0.5 to 200 μ.

Any one of the above-mentioned materials (a) to (e) and one having a sea-island structure may further contain silica, calcium carbonate, titanium oxide, zinc oxide, etc., if necessary. An extender pigment can be included.
As the method for forming the receiving layer 5, air knife coating, reverse roll coating,
It is applied by a coating method such as gravure coating or wire bar coating, and dried to form.

The receiving layer 5 can be directly provided on the base material 4, or can be provided on the base material 4 via an intermediate layer. The material of the intermediate layer, saturated polyester, polyurethane,
Examples include organic solvent solutions such as acrylic acid esters.
Examples of the method for forming the intermediate layer include reverse roll coating, gravure coating, wire bar coating, and the like, and the thickness of the layer is preferably 3 to 15 μm.

As the material for the intermediate layer, either or both of an aqueous solution of a water-soluble synthetic resin and 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. Synthetic resin emulsions include polyacrylic acid ester, ethylene / vinyl acetate copolymer,
Aqueous emulsions of synthetic resins such as 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 the method for forming the intermediate layer using the water-soluble synthetic resin or the aqueous emulsion, the above-mentioned coating means can be used, and in addition, the 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 in order to improve the coating suitability of the coating composition during formation, the blocking resistance of the coating film and the hiding power. . 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 intermediate layer.

The resin layer 6 has a core material 3 on one surface of the synthetic paper 2.
It also has an effect of playing a reinforcing role of preventing curling from the base material provided with, and imparting lubricity for facilitating taking out the heat-transferred sheets 1 one by one at the time of transfer.
The resin layer 6 includes a methacrylate resin such as a methyl methacrylate resin, an organic solvent solution such as a vinyl chloride-vinyl acetate copolymer resin or an emulsion thereof, a binder such as a synthetic rubber latex, and if necessary, clay, calcium carbonate, It can be formed by applying and drying a liquid to which a filler such as 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 6 can also be provided by extrusion coating of polyolefin or the like.

In the heat transferable sheet 1 of the present invention, an antistatic layer 7 can be provided on the side of the base material 4 on which the receiving layer 5 is not provided. For example, as shown in FIG. Can be provided. The antistatic layer 7 may be provided on the resin layer 6 by mixing an antistatic agent in the resin forming the resin layer 6 and bleeding the antistatic agent on the surface of the resin layer 6. Is. Antistatic agents include surfactants such as cationic surfactants (eg, quaternary ammonium salts, polyamine derivatives, etc.), anionic surfactants (eg, alkyl phosphates, etc.), zwitterionic surfactants. Agents or nonionic surfactants and the like. The antistatic layer 7 can be formed by gravure coating, bar coating or the like using the above-mentioned surfactant.

The heat-transferable sheet 1 of the present invention has a receptive layer 5 in order to improve releasability from the heat-transfer sheet, if necessary.
The release agent layer 8 can be formed on the surface of the receptor layer 5. For example, the release agent layer 8 can be provided on the surface of the receptor layer 5 as shown in FIG. Agents can be included. It is also possible to further incorporate a release agent into the receiving layer 5 and then bleed the release agent onto the surface of the receiving layer 5 so that a release agent layer is provided on the surface of the receiving layer 5. Examples of the material of the release agent layer 8 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. 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 receptive layer 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, and particularly preferably 0.
05-2 micrometer is preferable.

The thermal transfer sheet 1 of the present invention is the sheet 1
A phototube detection mark that can be detected by a phototube detection device or the like can be provided on the surface, preferably the back surface. By providing the mark, the transfer target sheet 1 can be accurately set at a predetermined position by a photoelectric tube detection device or the like at the time of transfer, and an image can be always formed at an accurate desired position. 1) Thermal transfer sheet 1 grade,
Type such as size is detected, 2) Heat transfer sheet 1
The accuracy of the front and back of the set is detected, and 3)
The direction of the heat-transferred sheet 1 is detected, and the heat-transferred sheet 1 is detected.
There is an advantage in the work process when actually performing the transfer. 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.

Next, the present invention will be described in more detail with reference to specific examples.

Example 1 An organic solvent solution of a polyurethane resin-polyisocyanate adhesive was applied to one surface of a synthetic paper having fine pores (thickness 110 μm, manufactured by Oji Synthetic Paper: YUPO FPG) (10 g / dry coating amount). m ² ), dried and cast-coated paper (US basis weight 84 g / m ² ) was attached to the surface to form a base material.
Then, a toluene / methyl ethyl ketone = 1/1 mixed solvent solution of a polyester resin (Toyobo: Byron 200) was applied onto the synthetic paper of the above-mentioned substrate using a wire bar (drying amount 7 g / m ² ) and dried. An intermediate layer was formed. Then, an ink composition for forming a receiving layer having the following composition was coated on the above intermediate layer by a reverse roll method (coating amount at dry time: 4 g / m ² ) and dried to form a receiving layer.

Ink Composition for Receptor Layer Formation Polystyrene resin (Hercules: Picotex 100) 15 parts by weight Toluene / methyl ethyl ketone = 1/1 mixed solvent 75 parts by weight Amino-modified silicone oil (KF393 manufactured by Shin-Etsu Chemical) .. 5 parts by weight 5 parts by weight of epoxy-modified silicone oil (X-22-343 manufactured by Shin-Etsu Chemical Co., Ltd.) Then, on the surface of the cast coated paper on the side without the receiving layer, toluene / methyl ethyl ketone of polymethylmethacrylate resin = 1 / One solution (concentration: 12%) was applied using a wire bar (applied dry amount of 4 g / m ² ) and dried to form a resin layer.

Next, a 1% isopropanol solution of an antistatic agent (Analytical Chemical Laboratory of Skokey: Statiside) was applied onto the above resin layer (coating amount at dry time: 0.1 g / m ² ) and dried. A heat transfer sheet was obtained.

On the other hand, an ink composition for forming a heat-resistant slip layer having the following composition was prepared on a polyethylene terephthalate film having a thickness of 6 μm, coated with a miya bar # 6, and dried with warm air.

Ink composition for forming heat-resistant slip layer Polyvinyl butyral resin (S-REC BX-1) 4.5 parts by weight Toluene 45 parts by weight Methyl ethyl ketone 45.5 parts by weight Phosphoric acid ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) Plysurf A-208S) 0.45 parts by weight Diisocyanate "Takenate D-110N" 75% ethyl acetate solution 2 parts by weight The above film was cured by heating in an oven at 60 ° C for 12 hours. The amount of ink applied after drying is about 1.2g
/ M ² .

Next, an ink composition for forming a heat-sensitive sublimation transfer layer having the following composition was prepared on the surface of the film opposite to the heat-resistant slip layer, and the composition was applied with a miya bar # 10 (applied amount: about 1.2 g / m 2). ² ) and dried with warm air to form a transfer layer to obtain a thermal transfer sheet.

Ink Composition for Forming Thermal Sublimation Transfer Layer Disperse Dye (Nippon Kayaku: Kayaset Blue 714) 4 parts by weight Polyvinyl butyral resin (Eslec BX-1) 4.3 parts by weight Toluene 40 40 parts by weight Methyl ethyl ketone ··· 40 parts by weight Isobutanol ··· 10 parts by weight The transfer layer of the thermal transfer sheet is faced to the receiving layer of the thermal transfer sheet obtained above, and a thermal transfer printer is used to transfer heat from the back side of the thermal transfer sheet. When an image was formed by heating with a head so as to obtain the highest image density, the image was not rough, the image density was good, and the curl of the heat-transferred sheet was hardly observed.

Example 2 A solution of chlorinated polypropylene in toluene / methyl ethyl ketone mixed solvent (weight ratio 1/1) was applied as a primer layer on one surface of synthetic paper (thickness 60 μ, made by Oji Oka Kasei Synthetic Paper: YUPO) (when dried) The coated amount was 0.5 g / m ² ) and the synthetic paper and high-quality paper (US basis weight 105 g / m ² ) were dry laminated with a urethane adhesive to form a substrate.

Next, a liquid prepared by mixing and dispersing clay (solid content weight ratio 1: 2) in styrene-butadiene latex was applied to the surface side of the high-quality paper of the above-mentioned substrate using a wire bar (coating amount when dry 8 g / M ² ) and dried to form a resin layer.

Next, the same intermediate layer as in Example 1 (coating amount on dry basis: 5 g / m ² ) was provided on the surface of the synthetic paper of the above base material,
Further, a receiving layer-forming composition having the following composition was applied onto the intermediate layer using a wire bar and dried, and a coating amount when dried was 3 g.
/ M ² of the receiving layer was formed to obtain a heat transferable sheet.

Receptor layer forming composition Polyester resin (Toyobo: Byron 200) 10 parts by weight Amino-modified silicone (Shin-Etsu Chemical: KF-393) ... 0.5 parts by weight Epoxy-modified silicone (Shin-Etsu Chemical: X-22-343) 0.5 parts by weight Solvent (toluene / methyl ethyl ketone = 1/1) 89 parts by weight An image was formed on the obtained heat-transferable sheet by using a thermal transfer sheet in the same manner as in Example 1. However, almost no curling of the heat-transferred sheet was observed.

Example 3 The same constitution as in Example 1 was used by using a synthetic paper (thickness 110 μm, Peachcoat WP-110 manufactured by Nisshinbo Co., Ltd.) manufactured by the pigment coating method and having no fine pores. A heat transfer sheet was formed.

An image was formed on the obtained heat-transferable sheet by using the heat-transfer sheet in the same manner as in Example 1. As a result, the curl was small, but the image was slightly uneven and the sharpness of the photographic image was poor. there were.

Example 4 First, a resin having the following composition was coated on one surface of a high quality paper having a thickness of 100 μm.

Resin composition Polypropylene (Mitsui Petrochemical: LA-221) 96 parts by weight Titanium (white) 4 parts by weight Next, synthetic paper (thickness 60 μ, made by Oji Yuka Synthetic Paper: YUPO FPG) Then, a resin having the above composition was used in the same manner and extrusion-laminated to form a base material so that the surface of the high-quality paper not coated with the resin was in contact with the surface. The same receiving layer as in Example 1 was formed on the surface of the above-mentioned base material on the side of the synthetic paper to obtain a heat transferable sheet.

An image was transferred and formed on the obtained heat-transferable sheet in the same manner as in Example 1. When the heat-transferred sheet was used, curl was hardly recognized and the quality was good.

Example 5 In Example 4, a 100 μm-thick quality paper was coated with a 100 μm-thickness.
An image was formed on the receiving layer of the heat transferable sheet in the same manner as in Example 4 except that the polypropylene was changed to a drawn polypropylene, and no curl was observed, and the quality was good.

[0050]

As described above, the heat transferable sheet of the present invention has a constitution in which the base material is the synthetic paper and the core material is attached to the base material, and the resin layer is provided on the side of the core material where the synthetic paper is not attached. Therefore, substantial thermal contraction due to heating of a thermal head or the like does not occur during transfer, and as a result, curling does not occur after image formation, and a problem due to curling in a conventional heat-transferred sheet is solved. In addition to this effect, it has the effect of being excellent in lubricity.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a heat transferable sheet of the present invention.

FIG. 2 is a vertical sectional view showing the constitution of the heat transferable sheet of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heat transfer sheet, 2 ... Synthetic paper, 3 ... Core material, 4 ... Base material, 5 ... Receptor layer, 6 ... Resin layer, 7 ... Antistatic layer, 8 ... Release agent layer

Claims (6)

[Claims] 1. A thermal transfer sheet having a substrate and a receiving layer for receiving a dye which migrates from the thermal transfer sheet when heated, wherein the substrate comprises a core material and synthetic paper adhered to one side thereof. A heat-transferable sheet, characterized in that a receiving layer is provided on the synthetic paper side of the base material either directly or via an intermediate layer, and a resin layer is provided on the side of the core material on which the synthetic paper is not adhered. 2. The heat transferable sheet according to claim 1, wherein the core material is a cellulose fiber paper or a plastic film. 3. The heat transfer sheet according to claim 1, wherein the synthetic paper is a synthetic paper provided with a paper-like layer containing fine pores. 4. The heat transferable sheet according to claim 1 or 2, wherein the synthetic paper comprises only a paper-like layer containing fine pores. 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 release layer is provided on the receiving layer.