JP2601439B2 - Thermal transfer sheet for color image formation - Google Patents

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 for forming a color image, and more particularly to a thermal transfer sheet for forming a color image which is useful for proof printing of various color prints which have been widely used in the past.

[0002]

2. Description of the Related Art Conventionally, a large amount of color printing is performed by offset printing, gravure printing, or the like. In such color printing, a manuscript is left as it is or another manuscript is printed.
Color separation is performed by combining characters, symbols, and the like, to create three primary color plates of cyan, magenta, and yellow. Further, if necessary, a black plate is added, and the hue and pattern of the original are reproduced with the respective printing inks.

In order to perform large-volume printing, it is necessary to check beforehand whether or not the color tone, layout, characters, symbols, etc. of the original and the printed matter match exactly before mass printing. Conventionally, a process called proof printing is performed. With such a proof, the color tone between the manuscript and the printed matter,
Layout and other dissimilarity checks,
From the beginning, the manuscript and the printed matter hardly match completely, and the printing plate is corrected each time for different points, and by repeating such a process several times, the manuscript and the printed matter are sufficiently matched. I have. Further, even when the original document is insufficient, the same operation is repeated to meet the request of the orderer.

[0004]

The above-described conventional proof printing process is an essential process when performing large-volume printing, but this process is very complicated, such as plate correction.
There is a strong demand for omitting or simplifying the proof printing process. However, at present, no means has been found which sufficiently satisfies these demands. The present inventor has solved the above-mentioned problems of the prior art, and as a result of earnest research to meet the above-mentioned demands, has found that the above-mentioned demands can be met by using a conventionally known thermal transfer technique. .

[0005]

That is, the present invention relates to a color image forming thermal transfer sheet comprising a base sheet and a dye supporting layer formed on one surface of the base sheet. The dye contained is C.I. I. Despers Red 60 and C.I. I. A color image forming thermal transfer sheet, which is a mixture with Despers Violet 26.

[0006]

The dye in the dye-carrying layer of the thermal transfer sheet has at least C.I. I. By using Disperse Red 60, it is possible to provide a thermal transfer sheet for color image formation useful for color matching of proof prints.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The main feature of the present invention is to select a specific dye exhibiting color reproducibility closest to the color tone of magenta printing ink among the three primary colors of conventional printing inks, particularly offset printing inks, from a myriad of conventionally known magenta dyes. That is, the thermal transfer sheet is formed.

Most of the three primary colors of conventional offset printing inks are composed of pigments, while the color materials used for the thermal transfer sheet are all sublimable (or heat transferable) dyes. Have different coloring mechanisms from each other, and it has been almost impossible to select a heat transferable dye that matches the three primary colors of the offset printing ink.

That is, in the present invention, C.I. I. Disperse Red 60 alone or C.I. I. Disperse Violet 26 and C.I. I. By using a mixture with Disperse Red 60, a color tone equivalent to the magenta ink of the offset printing ink can be reproduced. In addition, C.I. I. Disperse Red 60 and C.I. I. When a mixture with Disperse Violet 26 is used, the mixture ratio is preferably adjusted to C.I. I. Disperse Red 60 per part by weight of C.I. I. Disperse Violet 26 0.3
When the content is in the range of 1.0 to 1.0 parts by weight, the color tone corresponding to the magenta ink of the offset printing ink can be more preferably reproduced.

When a full-color image for proof printing is formed using the magenta thermal transfer sheet of the present invention,
The magenta thermal transfer sheet is used in combination with a cyan thermal transfer sheet and a yellow thermal transfer sheet. Dyes suitable for use in the cyan thermal transfer sheet include C.I.
I. Solvent Blue 63 and a dye represented by the following formula (I) (each of which can include a dispersant and the like, the same applies hereinafter), and the mixing ratio is preferably 2.0 to 8.0 parts by weight per 1 part by weight of the former. By using the mixture in the range of part, the color tone corresponding to the shear ink of the offset printing ink can be reproduced. If the mixing ratio is out of the range, the object cannot be achieved sufficiently.

Embedded image

A dye suitable for use in the yellow thermal transfer sheet is a dye represented by the following formula (II):
By using the dye, a color tone corresponding to the yellow color of the offset printing ink can be satisfactorily reproduced.

Embedded image

The above C.I. I. Disperse Red 6
0 is MS Red G (manufactured by Mitsui Toatsu Chemicals), C.I. I.
Disperse Violet 26 is Macrolex
Red Violet R (manufactured by Bayer), C.I. I.
Solvent Blue 63 is Kayaset Blue
714 (manufactured by Nippon Kayaku) and the dye represented by the formula (I) is Foron Brilliant Blue S-
R (manufactured by Sand), a dye represented by the formula (II):
Foron Brilliant Yellow S-
It can be obtained from the market as 6GL (made of sand) or the like and used in the present invention.

The thermal transfer sheet of the present invention is characterized by using the specific magenta dye as described above, and the other configuration may be the same as the configuration of a conventionally known thermal transfer sheet. As the base sheet used in the thermal transfer sheet of the present invention, any base sheet having conventionally known heat resistance and strength to some extent may be used. For example, paper having a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm, various processed papers, polyester film, polystyrene film, polypropylene film, polysulfone film, polycarbonate film, polyvinyl alcohol film, cellophane, etc. Particularly preferred are polyester films.

The dye-carrying layer provided on the surface of the substrate sheet as described above may be made of C.I. I. Disperse Red 60, or C.I.
I. Disperse Violet 26 and C.I. I. This is a layer in which a mixture with Disperse Red 60 is supported by an arbitrary binder resin. As the binder resin for supporting the dye, any of conventionally known binder resins can be used, and preferred examples thereof include ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate and the like. Cellulose resins, polyvinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl pyrrolidone, and polyacrylamide, and polyester resins are preferred from the viewpoints of heat resistance, dye transferability, and the like.

The dye-carrying layer of the thermal transfer sheet of the present invention is basically formed of the above-mentioned materials, but may also contain various additives as conventionally known, if necessary. Such a dye-carrying layer is preferably prepared by adding the above-mentioned dye, binder resin and other optional components in an appropriate solvent and dissolving or dispersing each component to prepare a coating solution or ink for forming a supporting layer. Is applied and dried on the above-mentioned base sheet. The dye-carrying layer thus formed has a thickness of 0.1 mm.
It has a thickness of about 2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the dye in the support layer accounts for 5 to 70% by weight, preferably 10 to 60% by weight of the weight of the support layer. It is preferably present in an amount of

Although the thermal transfer sheet of the present invention as described above is sufficiently useful as it is for thermal transfer as it is, an anti-adhesion layer, that is, a release layer may be further provided on the surface of the dye-carrying layer. Is provided, it is possible to prevent sticking between the thermal transfer sheet and the material to be transferred at the time of thermal transfer, to use a higher thermal transfer temperature, and to form an image with even better density.

As the release layer, even if only an anti-adhesive inorganic powder is adhered, a considerable effect is exhibited.
For example, from a resin having excellent releasability such as silicone polymer, acrylic polymer, and fluorinated polymer, 0.01 to
It can be formed by providing a release layer of 5 μm, preferably 0.05 to 2 μm. The inorganic powder or the releasable polymer as described above has sufficient effects even if it is included in the dye-carrying layer. Further, a heat-resistant layer may be provided on the back surface of such a thermal transfer sheet in order to prevent adverse effects due to the heat of the thermal head.

The transfer material used to form an image using the above-described thermal transfer sheet may be any material as long as its recording surface has a dye-accepting property for the dye. In the case of paper, metal, glass, synthetic resin or the like having no dye receptivity, a dye receiving layer may be formed on at least one surface thereof. Examples of the transfer material that does not need to form a dye receiving layer include, for example, polyolefin resins such as polyethylene and polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, polyvinyl acetate, and vinyl such as polyacrylester. Polymers, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers,
Ionomers, cellulose resins such as cellulose diacetate and cellulose triacetate, polycarbonate, polysulfone, fibers made of polyimide, etc., woven fabrics,
Films, sheets, molded products and the like can be mentioned.

Particularly preferred is a sheet or film made of polyester or a processed paper provided with a polyester layer. Further, even for paper, metal, glass, and other non-dyeable transfer receiving materials, the recording surface is coated with a solution or dispersion of the above-described dyeable resin and dried, or the resin By laminating the film, a material to be transferred can be obtained.

Further, even in the case of the above-mentioned transferable material having dyeing properties, a dye-receiving layer may be formed on the surface thereof from a resin having better dyeing properties as in the case of the above-mentioned paper. . The dye receiving layer formed in this way can be made of a single material,
Further, it may be formed from a plurality of materials, and may further include various additives as long as the intended purpose is not hindered.

The dye receiving layer as described above may have any thickness, but generally has a thickness of 5 to 50 μm. Further, such a dye receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating using a resin emulsion or a resin dispersion. The material to be transferred is basically as described above, and can be used satisfactorily as it is. However, the above-mentioned material to be transferred or its dye receiving layer can contain an inorganic powder for preventing adhesion. In this way, even if the temperature at the time of thermal transfer is further increased, adhesion between the thermal transfer sheet and the material to be transferred can be prevented, and more excellent thermal transfer can be performed. Particularly preferred is finely divided silica.

In place of or in combination with the above-mentioned inorganic powder such as silica, the above-mentioned resin having good releasability may be added. A particularly preferred release polymer is a cured product of a silicone compound, for example, a cured product composed of an epoxy-modified silicone oil and an amino-modified silicone oil. Such a release agent preferably accounts for about 0.5 to 30% by weight of the weight of the dye receiving layer. Further, the surface of the dye receiving layer of the transfer material to be used may be made to adhere to the inorganic powder as described above to enhance the anti-adhesion effect, or from the above-described release agent having excellent release properties. May be provided.
Such a release layer has a sufficient effect at a thickness of about 0.01 to 5 μm, and can further improve the dye receptivity while preventing adhesion to the dye receiving layer of the thermal transfer sheet.

As the means for applying thermal energy used when performing thermal transfer using the thermal transfer sheet of the present invention as described above and the recording material as described above, any conventionally known applying means can be used. For example, a thermal printer (for example, thermal printer TN-540 manufactured by Toshiba)
By controlling the recording time with a recording device such as 0), the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² .

[0024]

Next, the present invention will be described more specifically with reference to examples and reference examples. In the following description, parts and% are based on weight unless otherwise specified. Example 1 An ink composition for forming a dye-carrying layer having the following composition was prepared, and coated and dried on a 9 μm-thick polyethylene terephthalate film having a heat-treated back surface so that the dry coating amount was 1.0 g / m ^2. Thus, a thermal transfer sheet of the present invention was obtained.

Magenta MS Red G 2.86 parts Macrolex Red Violet R 1.56 parts Polyvinyl butyral resin 4.32 parts Methyl ethyl ketone 43.34 parts Toluene 42.92 parts Cyclohexanone 5.00 parts

Next, a synthetic paper (Yupo FPG # 150, manufactured by Oji Oil Chemical Co., Ltd.) was used as a base sheet, and a coating solution having the following composition was dried on one of the surfaces at a rate of 4.5 g / m ² when dried. And dried at 100 ° C. for 30 minutes to obtain a transfer-receiving material. Polyester resin (Vylon 200, manufactured by Toyobo) 11.5 parts Vinyl chloride / vinyl acetate copolymer (VYHH, manufactured by UCC) 5.0 parts Amino-modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts Epoxy-modified series Corn (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts Methyl ethyl ketone / toluene / cyclohexanone (weight ratio 4: 4: 2) 102.0 parts

REFERENCE EXAMPLE 1 An ink composition for forming a dye-carrying layer having the following composition was prepared and applied to a 9 μm-thick polyethylene terephthalate film having a heat-resistant back surface so that the dry coating amount was 1.0 g / m ² . Coating and drying were performed to obtain cyan and yellow thermal transfer sheets. Cyan color Blueset 714 1.00 parts Foron Brilliant Blue SR 4.80 parts (containing dispersant) Polyvinyl butyral resin 4.60 parts Methyl ethyl ketone 44.80 parts Toluene 44.80 parts

Yellow Foron Brilliant Yellow S-6GL 6.00 parts (containing dispersant) Polyvinyl butyral resin 4.52 parts Methyl ethyl ketone 43.99 parts Toluene 40.99 parts Cyclohexanone 4.50 parts Magenta thermal transfer sheet of the present invention described above. And, the cyan and yellow thermal transfer sheet of the reference example and the transfer material,
Each of the dye-carrying layer and the dye-receiving surface are opposed to each other and overlapped,
A head applied voltage of 10 V and a printing time of 4.0 msec. Recording was performed with a thermal head under the conditions described above, and three-color images were obtained. When the color rendering properties of these three color images were compared with a proof print image using a standard color of an offset printing ink (G set ink, manufactured by Morohoshi ink), good agreement was observed.

[0029]

By using the thermal transfer sheet of the present invention as described above, the color separation of the original is performed by a color scanner prior to performing a large amount of color printing by various printing methods, particularly, the offset printing method. By connecting a thermal transfer recording device equipped with a computer and performing color printing and replacing it with proof printing, color correction of printed matter, layout change, insertion of symbols, characters, other manuscripts etc. Can be finally determined by processing on a computer without creating or modifying the. Therefore, by preparing the final plate in the state determined in this way, a complicated proof printing process as in the prior art is greatly simplified.

Claims (1)

(57) [Claims] 1. A color image forming thermal transfer sheet comprising a base sheet and a dye-carrying layer formed on one surface of the base sheet, wherein the dye contained in the dye-carrying layer is C.I. I. Despers Red 60 and C.I. I. Desperate
A thermal transfer sheet for forming a color image , which is a mixture with Violet 26 .