JPH05286273A - Thermal transfer sheet and thermal transfer method - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer sheet and a thermal transfer method by which a high-quality and high-density image can be formed with a high dye transfer efficiency even on a transfer medium having no dyeability. CONSTITUTION:On one surface of a substrate film 11, dye layers 12 of one or more colors and one or more accepting layers 14 are provided in a face sequential manner. A release layer 15 is provided between the accepting layer 14 and the substrate film 11. A binder in the dye layers 12 and a binder in the release layers 15 are made of resins having releasability to the accepting layers 14. At least one or more of the resins are commonly used for both the binders.

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 and a thermal transfer method, and more particularly to a thermal transfer sheet and a thermal transfer method capable of forming a high quality and high density image.

[0002]

2. Description of the Related Art Conventionally, when the output printing of a computer or a word processor is performed by a thermal transfer system, a thermal transfer sheet having a dye layer provided on one surface of a base film is used. This thermal transfer sheet is provided with a heat-resistant base film and a dye layer formed by applying and drying an ink in which a sublimable dye is mixed in a binder on the base film. Then, heat is applied from the back side of the thermal transfer sheet by the thermal head to transfer a large number of color dots of three colors or four colors to the transfer material to form a full color image. The formed image is clear and excellent in transparency because the color material used is a dye, and the reproducibility and gradation of intermediate colors are high, and it is possible to form high-quality images equivalent to conventional full-color photographic images. ..

However, it is impossible to form a high-quality image as described above on a transfer material having no dye-dyeing property such as ordinary plain paper. A dye receiving layer is formed in advance on a transfer material having no sticking property.

[0004]

To form a dye receiving layer in advance on a material to be transferred, a method of applying a coating liquid for the receiving layer and a method for applying the coating for the receiving layer on a substrate film in advance are used. There is a method of transferring a receiving layer formed by applying a liquid to a transfer material. In the latter method, it is necessary to peel off the receiving layer from the base film well when transferring the receiving layer to the transfer material. Therefore, it is necessary to interpose a peeling layer between the base film and the receiving layer. Is being done.

This peeling layer is required to have good peelability from the receiving layer and also to have a certain degree of adhesiveness to the receiving layer in order to make the film breaking of the receiving layer good. To be done. Then, as a method for providing adhesiveness between the release layer and the receiving layer, a coating liquid for the receiving layer is applied before the release layer applied on the base film is completely solidified. Therefore, there is a method in which the release layer and the receiving layer are slightly mixed at the interface.

However, when the release layer and the receptive layer are slightly mixed at the interface as described above, when the receptive layer is transferred to the transfer material, the release layer and the receptive layer are completely mixed at the interface. Does not separate, and a minute amount of the release layer is transferred to the transfer material together with the receiving layer. Then, when the transfer is performed on the receiving layer where the release layer remains in this way, the dye layer of the thermal transfer sheet is fused with the receiving layer, or the sensitivity is lowered (the transfer amount of the dye is reduced).
The problem occurs.

The present invention has been made in view of the above circumstances, and is applicable to a transfer material having no dye dyeing property.
An object of the present invention is to provide a thermal transfer sheet and a thermal transfer method, which have high dye transfer efficiency and are capable of forming a high-quality and high-density image.

[0008]

In order to achieve such an object, the thermal transfer sheet of the present invention comprises a base film and one or more dyes which are provided on one surface of the base film in a frame-sequential manner. Layer and one or more receiving layers, and a release layer between the receiving layer and the base film, and the binder of the dye layer and the release layer are peeled from the receiving layer. In addition to being composed of a resin having properties, at least one kind of the constituent resins is common.

Further, in the thermal transfer method of the present invention, after the receiving layer provided on the substrate film via the release layer is transferred onto the material to be transferred, heat is applied from the back surface of the thermal transfer sheet to the thermal transfer sheet. In the thermal transfer method of transferring a dye from the dye layer provided on the surface of the dye to the receiving layer on the transfer material, the binder of the dye layer and the release layer are formed of a resin having releasability with respect to the receiving layer. And at least one of the constituent resins is common.

[0010]

[Function] Even if a slight amount of the releasing layer remains on the surface of the receiving layer transferred onto the material to be transferred, the binder and the releasing layer of the dye layer of the thermal transfer sheet are made of a resin having releasability from the receiving layer. Since it is composed of at least one kind of common resin, the dye in the dye layer reaches the receiving layer through the residual release layer, while the residual release layer serves as a binder of the dye layer. It is removed together from the surface of the receiving layer. This prevents fusion between the dye layer and the receiving layer of the thermal transfer sheet, improves the dye transfer efficiency, and enables high-quality and high-density image formation.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of the thermal transfer sheet of the present invention. In FIG. 1, a thermal transfer sheet 10 includes a base film 11 and a dye layer 1 on one surface of the base film 11.
2 (Yellow 12Y, Magenta 12M, Cyan 12C)
And a receiving layer 14 are provided in a frame-sequential manner, and the receiving layer 14 is formed on the base film 11 via the release layer 15 so as to be peelable. An adhesive layer 16 is provided on the above.

As the base film 11, the base film used in the conventional thermal transfer sheet can be used as it is and is not particularly limited. For example, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, plastic films such as ionomer, glassine paper, condenser paper, Paper such as paraffin paper and non-woven fabric are preferably used. Moreover, these composites can also be used as a base film.

The thickness of such a base film can be appropriately determined so as to obtain the required strength and thermal conductivity, and is, for example, about 3 to 100 μm. Dye layer 1
Reference numeral 2 is a layer in which a dye is supported by a binder. As the dye, the dye used in the conventional thermal transfer sheet can be used as it is and is not particularly limited. For example, the preferred dye is MS as the red dye.
Red G, Macrolex Red Violet R, Ceres Red HBSL, Reso
lin Red F3BS and the like, yellow dyes such as Holon Brilliant Yellow 6GL, PTY-52, Macrolex Yellow 6G and the like, and further blue dyes such as Kayaset Blue 714, Waxolin Blue AP-FW and Holon. Brilliant blue SR, MS blue 100 and the like can be mentioned.

The binder for carrying the dye as described above is composed of a resin having releasability with respect to the receiving layer 14, and also has at least one kind in common with the constituent resin of the releasing layer 15 described later. Is. As such a binder, for example, acetoacetal resin, polyvinyl butyral resin, acetal resin such as polyvinyl formal resin, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate resin such as cellulose acetate butyrate, polyvinyl alcohol, Examples thereof include polyvinyl resins such as polyvinylpyrrolidone and polyacrylamide, polyesters, urethane resins and the like. Among these, cellulose type, acetal type, butyral type and polyester type are particularly preferable. Of these resins, the resin common to the constituent resin of the release layer 15 is about 10 to 100% by weight in the binder, preferably 30 to 80% by weight.
Included to some extent.

In addition to the above-mentioned dyes and binders, the dye layer 12 may contain various conventionally known additives as required. Then, the above dye in a suitable solvent,
A binder and additives are added to dissolve or disperse each component to prepare an ink, which is applied and dried on the above-mentioned base film by a known means to form the dye layer 12.

The dye layer thus formed is 0.1
.About.5.0 .mu.m, preferably about 0.4 to 2.0, and the dye layer contains 5 to 90% by weight, preferably 10 to 70% by weight of the dye.

The release layer 15 is an acetal resin such as acetoacetal resin, polyvinyl butyral resin or polyvinyl formal resin, a cellulose resin such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate or cellulose acetate butyrate, polyvinyl alcohol. , Vinylpyrrolidone, polyacrylamide, and other vinyl resins, polyester, urethane resins, and other resins. Further, these resins may be used as a binder to contain a releasing agent such as silicone oil, a phosphoric acid ester-based surfactant, or a fluorine-based surfactant, or a surfactant. At least one kind of resin forming the release layer 15 is common to the resin forming the binder of the dye layer. As a result, even if a small amount of the release layer 15 remains on the surface of the receiving layer 14 transferred onto the transfer material, the dye in the dye layer 12 remains on the surface of the receiving layer 14. The release layer can be easily passed through to reach the receiving layer. During transfer, the release layer remaining on the surface of the receiving layer 14 is easily fused and integrated with the binder of the dye layer 12 and removed from the surface of the receiving layer 14. This prevents fusion between the dye layer and the receiving layer of the thermal transfer sheet, and improves the dye transfer efficiency.

In the release layer 15 as described above, acetal resin and cellulose resin are particularly preferable as the resin common to the resin constituting the binder of the dye layer. Further, the resin which is common to the resin constituting the binder of the dye layer is contained in the release layer 15 in an amount of about 10 to 100% by weight, preferably about 30 to 80% by weight.

For such a release layer 15, an ink prepared by dissolving or dispersing the above resin with necessary additives added in a suitable solvent is prepared on a base film by a known means. It is formed by coating and drying, and the thickness is 0.5-
It is preferably about 5 μm.

The receiving layer 14 is for receiving sublimable dyes transferred from the thermal transfer sheet after being transferred to any transfer target and maintaining the formed pixels. Examples of the resin for forming the receiving layer 14 include polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylic ester, polyethylene terephthalate and poly Examples include polyester resins such as butylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulose resins such as cellulose diacetate, and polycarbonate. Particularly preferred are vinyl resins and polyester resins.

The receptive layer 14 is an ink prepared by dissolving or dispersing the above-mentioned resin with necessary additives in a suitable solvent to form a release layer already formed on the base film. It is formed by coating and drying on 15 by a known means. Additives contained in the receiving layer 14 include titanium oxide, zinc oxide, and kaolin for the purpose of improving the whiteness of the receiving layer to further improve the sharpness of the transferred image and improving the film breakage of the receiving layer. Pigments and fillers such as clay, calcium carbonate and finely divided silica can be used.
The thickness of the receiving layer 14 is preferably about 1 to 20 μm.

The adhesive layer 16 is used for favorably transferring the receiving layer 14 to the transferred material. For example, polyamide resin, acrylic resin, vinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin, polyester. It is formed by applying and drying a solution of heat-sensitive adhesive resin such as resin.
The thickness of the adhesive layer 16 is preferably about 0.5 to 10 μm.

In order to form the receiving layer on the transferred material, the above-mentioned releasing layer 15, receiving layer 14 and adhesive layer 16 are formed on the base film without using the above-mentioned composite type thermal transfer sheet. You may use the receiving layer transfer sheet laminated | stacked.

A back layer may be provided on the back surface of the base film. The back layer is formed from a binder resin and other necessary additives. Examples of the binder resin include ethyl cellulose, hydroxyethyl cellulose,
Hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose resin such as nitrified cotton, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, acrylic resin, polyacrylamide, acrylonitrile-styrene copolymer, etc. Vinyl resin,
Examples thereof include polyester resin, polyurethane resin, silicone-modified or fluorine-modified urethane and the like. Among these, it is preferable to use a resin having some reactive groups, for example, a hydroxyl group, and use a polyisocyanate or the like as a crosslinking agent to form a crosslinked resin layer.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental example 1) A release layer coating solution having the following composition was applied to the surface of a 6 μm-thick polyester film (Lumirror manufactured by Toray Industries, Inc.) as a base film in a film flow direction of 90 cm.
A coating layer having a width of 30 cm was applied with a bar coater at an interval of (application amount = 0.2 g / m ² (dry)) and dried to form a release layer.

(Composition of coating liquid for release layer) Acetoacetal resin (KS-1 manufactured by Sekisui Chemical Co., Ltd.) 100 parts by weight Methyl ethyl ketone / toluene (weight ratio 1/1) 400 parts by weight , A receptive layer coating solution having the following composition was applied by a bar coater so as to be aligned with the release layer (coating amount =
3 g / m ² (when dried)), after temporary drying with a dryer, 10
Dry in an oven at 0 ° C. for 30 minutes to form a receptive layer,
Further, an adhesive solution having the following composition was similarly applied so as to be aligned with the above-mentioned receiving layer (application amount = 2 g / m ² (dry)) and dried to form an adhesive layer.

(Composition of coating liquid for receiving layer) -Vinyl chloride / vinyl acetate copolymer resin (1000A manufactured by Denki Kagaku KK) 100 parts by weight-Epoxy-modified silicone (KF- manufactured by Shin-Etsu Chemical Co., Ltd.) 393) 4 parts by weight Amino-modified silicone (X-22-343 manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts by weight Methyl ethyl ketone / toluene (weight ratio 1/1) 400 parts by weight (composition of adhesive solution) Acrylic resin (BR-106 manufactured by Mitsubishi Rayon Co., Ltd.) 100 parts by weight Methyl ethyl ketone / toluene (weight ratio 1/1) 400 parts by weight Next, an ink for a cyan dye layer having the following composition is received by a gravure coater. 90 cm in the area where no layer is formed
Apply with a width of 30 cm at intervals (application amount = 1.5 g
/ M ² (when dried)) and dried to form a cyan dye layer.

(Ink Composition for Cyan Dye Layer) Cyan Disperse Dye (Kayaset Blue 714 manufactured by Nippon Kayaku Co., Ltd.) ... 4.0 parts by weight Acetacetal resin (KS-1 manufactured by Sekisui Chemical Co., Ltd.) ... 5.0 parts by weight Similarly, in the above ink composition, the disperse dye was replaced with a yellow disperse dye (Hollon Brilliant Yellow 6G manufactured by Sand).
L), the ink for the yellow dye layer and the disperse dye are magenta disperse dyes (MS Red manufactured by Mitsui Toatsu Chemicals Inc.)
Using the magenta dye layer ink described in G), a yellow dye layer and a magenta dye layer were formed face-sequentially to obtain a thermal transfer sheet (Sample-1) of the present invention.

A thermal transfer sheet of the present invention was prepared in the same manner as in Sample 1 except that a cellulose resin (EHEC manufactured by Hercules Co., Ltd.) was used in place of the acetoacetal resin as the binder for the release layer resin and the dye layer. (Sample-2) was obtained.

Further, a polyvinyl alcohol (NH-26 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was used in place of the acetoacetal resin as the binder for the resin of the release layer and the dye layer. An inventive thermal transfer sheet (Sample-3) was obtained.

For comparison, a thermal transfer sheet (comparative sample) was prepared in the same manner as in Sample-1, except that the release layer was the same as that of Sample-1 and the dye layer was the same as that of Sample-2. -1) was obtained.

A thermal transfer sheet (comparative sample-Comparative Sample-) was prepared in the same manner as in Sample-1, except that the release layer was the same as the release layer of Sample-1 and the dye layer was the same as the dye layer of Sample-3. 2)
Got

Next, with respect to each of the thermal transfer sheets (Samples 1 to 3 and Comparative Samples 1 to 2) obtained as described above, the receiving layer surface (adhesive layer surface) and plain paper were superposed on each other and a thermal head was used. Under the conditions described above, plain paper was transferred onto the entire surface of the receiving layer.

(Receiving layer transfer conditions) -Output: 1 W / dot-Pulse width: 0.3 msec.-Dot density: 3 dots / mm Subsequently, a yellow dye layer was overlaid on each receiving layer to obtain a yellow signal. Based on the printing, a yellow image was formed. In addition, a magenta dye layer was overlaid on each of the receiving layers and printing was performed based on a magenta signal to form a magenta image on the yellow image. Further, a cyan dye layer was overlaid on each of the receiving layers, printing was performed based on a cyan signal to form a yellow image and a cyan image on the magenta image, thereby forming a full-color image. The sensitivity of the full-color image thus formed was measured with a Macbeth densitometer, and relative comparison was performed.

[0035]

[Table 1] As shown in Table 1, the thermal transfer sheet of the present invention (Sample 1
3), the sensitivity was good even if a slight amount of the release layer remained on the surface of the receiving layer transferred on the plain paper, the dye transfer efficiency was high, and high-quality and high-density image formation was possible. .. However, in the comparative thermal transfer sheets (Comparative Samples 1 and 2), the dye transfer efficiency was low and the image density was insufficient.

[0036]

As described in detail above, according to the present invention, even when a trace amount of the releasing layer is transferred to the transfer material together with the receiving layer and transfer is performed on the receiving layer where the releasing layer remains, the dye The dye in the layer reaches the receptor layer through the residual release layer, so that the dye transfer efficiency is high, and the residual release layer is removed from the surface of the receptor layer together with the binder of the dye layer, and the thermal transfer sheet is formed. The fusion of the dye layer and the receiving layer is prevented, and high quality and high density image formation becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a thermal transfer sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Thermal transfer sheet 11 ... Base film 12 ... Dye layer 14 ... Receiving layer 15 ... Release layer 16 ... Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 31/00 C 9012-2C

Claims (3)

[Claims] 1. A base film, a base film, a dye layer of one or more colors and one or more receiving layers provided on one side of the base film in a frame order, and the receiving layer and the base film. And a release layer between the dye layer and the release layer are composed of a resin having releasability with respect to the receiving layer, and at least one of the constituent resins is common. A thermal transfer sheet characterized by being a thing. 2. A transfer layer is provided on the surface of the thermal transfer sheet by transferring heat from a back surface of the thermal transfer sheet after transferring a receiving layer provided on a base material film via a release layer onto a transfer material. In a thermal transfer method for transferring a dye from a dye layer to the receiving layer on a material to be transferred, the binder of the dye layer and the release layer are composed of a resin having releasability with respect to the receiving layer, and the constituent resin The thermal transfer method is characterized in that at least one of them is common. 3. The thermal transfer method according to claim 2, wherein the thermal transfer sheet is one in which the dye layer and the receiving layer are provided in a surface sequential manner on one surface of a substrate film.