JPS62255187A - Thermal transfer sheet for forming color picture - Google Patents

Abstract

PURPOSE:To enable the remarkable simplification of a complicated galley proof process, by using the thermal transfer sheet for forming a color picture consisting of at least 3 kinds of thermal transfer sheets having respective dye carrying layers containing specific dyes of cyan, magenta, and yellow. CONSTITUTION:As a cyan dye, C.I. solvent blue 63 and the dye represented by formula (I) (either may contain dispersing agent and so on) are combined and preferably made into the mixture of which the mixing ratio is a range of 2.0-8.0pts.wt. the latter per 1pt.wt. of the former. Further, as a magenta dye, C.I. disperse red 60 and C.I. disperse violet 26 are made the mixture of which the mixing ratio is preferably a range of 0.3-1.0pt.wt. the latter per 1pt.wt. of the former. Further, the dye represented by formula (II) is used as a yellow dye. Thereby, color tone corresponding to each color of offset printing ink can be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal transfer sheet for color image formation, and more particularly to a color image formation sheet useful for proof printing of various color printings conventionally widely used commercially. The present invention relates to a thermal transfer sheet for use.

(Prior art) Conventionally, a large amount of color printing has been performed using offset printing, gravure printing, etc. When printing in color, the original is used as it is, or it is color separated by combining other originals, characters, symbols, etc. Then, plates for the three primary colors of cyan, magenta, and yellow are created, and a black plate is added as necessary to reproduce the hue, pattern, etc. of the original using each printing ink.

In order to print in large quantities, it is necessary to check in advance whether the color tone, layout, characters, symbols, etc. of the original and printed matter exactly match before printing in large quantities. A process called printing is being carried out. These proofs are used to check the color tone, layout, and other differences between the manuscript and the printed matter, but the manuscript and the printed matter are rarely exactly the same from the beginning, and the printed version is checked each time for differences. By making the following corrections and repeating this step several times, the manuscript and printed matter are sufficiently consistent. Additionally, even if the manuscript itself is insufficient, similar operations are repeated to meet the requests of the orderer.

(Problem to be solved by the invention) The proof printing process as described above is an essential process when performing mass printing, but this process is very complicated, such as plate correction, and the proof printing process can be omitted. Alternatively, there is a strong demand for cylindrical elements. However, at present, no means have been found that satisfactorily meet these demands.

The present inventor solved the problems of the prior art as described above,
As a result of intensive research to meet these two demands, the present invention was completed based on the finding that the above demands could be met by utilizing conventionally known thermal transfer technology.

(Means for Solving the Problems) That is, the present invention provides a thermal transfer sheet for color image formation comprising at least three types of thermal transfer sheets each having a dye-carrying layer containing a dye of each hue of cyan, magenta, and yellow. In the cyan dye labeled C. I.
It is a mixture of Solvent Blue 63 and a dye represented by the following formula (I), and the magenta dye is a mixture of C.I. I. Disbird's Red 60 and C.I. I. This is a thermal transfer sheet for forming a color image, which is a mixture of Disperse Eyelet 26, and the yellow dye is a dye represented by the following formula (n).

Star 4H9 Next, to explain the present invention in more detail, the main feature of the present invention is that from the countless known dyes for thermal transfer sheets, the three primary colors of conventional printing ink and offset printing ink, namely cyan, The key point is that the dyes closest to the magenta and yellow printing ink tones were selected, and thermal transfer sheets of the respective tones were prepared.

Most of the three primary colors of conventional offset printing inks are composed of pigments, but on the other hand, the coloring materials used in thermal transfer sheets are all sublimable (or heat transferable) dyes; The mechanism is different, and it has been almost impossible to select a heat-transferable dye that matches the three primary colors of the offset printing ink.

The present inventor further researched the selection of dyes that almost matched the three primary colors of printing ink, and found that for colors other than yellow, it was impossible to reproduce the three primary colors of printing ink with only one type of dye, but for cyan and magenta. discovered that the three primary colors of printing ink can be reproduced by combining two specific dyes.

That is, in the present invention, C.I. I
．． Solvent Blue 63 and the dye represented by (I) above (both may contain a dispersant, etc., the same applies hereinafter) are combined, preferably at a mixing ratio of 1 part by weight of the former to 2.0 parts by weight of the latter.
By making the mixture in the range of 0 to 8.0 parts by weight,
It is possible to reproduce the color tone equivalent to cyan ink of offset printing ink. If the mixing ratio falls outside of this range, the object of the present invention will not be fully achieved.

Moreover, as a magenta dye, C. I. Disbirds Red 60 and C. I. Disperse Eye Iolette 26
Preferably, the mixing ratio is 1 part by weight of the former to 0 part by weight of the latter.
．． By using a mixture in the range of 3 to 1.0 parts by weight, a color tone corresponding to magenta ink of offset printing ink can be reproduced.

If the mixing ratio is outside this range, the object of the present invention cannot be achieved within 1 minute.

Further, by using the dye represented by the formula (II) as the yellow dye, it is possible to reproduce a color tone corresponding to the yellow color of Offsera i printing ink.

In addition, the above C. I. Solvent Blue 63 is Kayas
etBlue 714 (manufactured by Nippon Kayaku), the above formula (I
) The dye represented by Foron Brllia
nt Blue S-R (manufactured by Sandoz), C. I. Disbirds Red 28 is 1.5RedG (manufactured by Mitsui Toatsu Chemical), C. I. Disperse violet is Macrolex Red Violet R (manufactured by Bayer), and the dye represented by formula (II) is F
oron Br1lliant Yellow 5-B
It is available on the market as GL (manufactured by Sandoz) and the like.

The present invention utilizes a combination of specific dyes as described above,
Three-color thermal transfer sheets of cyan, magenta, and yellow are provided, respectively, but these three-color thermal transfer sheets may be separate thermal transfer sheets, or a continuous base sheet''-1 of your choice. A dye-carrying layer containing dyes of two colors may be formed in this order, and any conventionally known black-colored thermal transfer sheet may be combined with these embodiments.

By using a thermal transfer sheet like the one described above, before printing a large amount of color using conventional offset printing, the colors of the original can be separated using a color scanner, and a thermal transfer recording device equipped with a computer can be connected to this. By printing in color and using it as a proof, you can correct the colors of printed matter, change the layout, insert symbols, characters, other documents, etc. without having to create or modify a plate each time. The final decision can be made through computer processing.

The thermal transfer sheet of the present invention is characterized by using a specific combination of three colors of dyes as described in -1- below, and other than that, the structure may be the same as that of a conventionally known thermal transfer sheet.

The base sheet used in the construction of the thermal transfer sheet of the present invention containing the above-mentioned dye may be any conventionally known material having a certain degree of heat resistance and strength, for example, 0.5 to 50 gm, Preferably 3 to 10/1. Examples include paper with a thickness of about 200 m, various processed papers, polyester films, polystyrene films, polypropylene films, polysulfone films, polycarbonate films, polyvinyl alcohol films, cellophane, etc., with polyester films being particularly preferred.

The dye-carrying layer provided on the surface of the base sheet as described above is a layer in which the dye is supported by any binder resin.

As the binder resin for supporting the dye,
Any conventionally known ones can be used, and preferred examples include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose acetate butyrate, polyvinyl alcohol, and polyacetic acid. Vinyl resins such as vinyl, polyvinyl butyral, polyvinyl pyrrolidone, and polyacrylamide, polyester, etc. are heat resistant.

This is preferable from the viewpoint of dye migration.

The dye-carrying layer of the thermal transfer sheet of the present invention is basically formed from the above-mentioned materials, but may also contain various conventionally known additives as required.

Such a dye-carrying layer is preferably prepared by adding the above-mentioned combinations of dyes, binder resin, and other optional components to a suitable solvent and dissolving or dispersing each component to prepare a coating liquid or ink for forming a compatible layer. and add this to the above base material sheet]
- Form by coating and drying.

The support layer formed in this way has a density of 0.2 to 5,0
gm, preferably about 0.4 to 2.0 #Lm, and the dye in the carrier layer has a thickness of about 5 to 2.0 #Lm of the weight of the carrier layer.
Suitably it is present in an amount of 70% by weight, preferably 10-60% by weight.

The thermal transfer sheet of the present invention as described above is fully useful for thermal transfer as it is, but it is also possible to provide an anti-adhesive layer, that is, a release layer, on the surface of the dye-carrying layer. This prevents adhesion between the thermal transfer sheet and the transfer material during thermal transfer, allows use of a higher thermal transfer temperature, and forms images with even better density.

As this mold release layer, even if an inorganic powder with anti-adhesive properties is simply attached, it has a considerable effect. It can be formed by providing a release layer of 0.01 to 5 pLm, preferably 0.05 to 2 gm.

Incidentally, the inorganic powders or release polymers described in [2] can exhibit sufficient effects even if they are included in the dye-carrying layer.

Furthermore, a heat-resistant layer may be provided on the back surface of such a thermal transfer sheet in order to prevent adverse effects caused by the heat of the thermal head.

The transfer material used to form an image using the thermal transfer sheet as described above may be any material as long as its recording surface has dye receptivity to the above-mentioned dyes. If the material is paper, metal, glass, synthetic resin, etc., which does not have a dye, a dye-receiving layer may be formed on at least one surface thereof.

Examples of transfer materials that do not require the formation of a dye-receiving layer include polyolefin resins such as polyethylene and polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetate, and polyacrylic ester. vinyl polymers such as polyethylene terephthalate, polyester resins such as polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers,
Examples include fibers, woven fabrics, films, sheets, and molded products made of cellulose resins such as cellulose diacetate and cellulose triacetate, polycarbonate, polysulfone, and polyimide.

Particularly preferred are sheets or films made of polyester or processed paper provided with a polyester layer. In addition, even if the transfer material is non-dyeable such as paper, metal, glass, etc., a solution or dispersion of a dyeable resin as described in 1-1 is applied and dried on the recording surface, or By laminating the resin film, it can be used as a transfer material.

Furthermore, even if the transfer material has the dyeability described above, a dye-receiving layer may be formed on the surface thereof from a resin having better dyeability, as in the case of the paper described above.

The dye-receiving layer thus formed can be formed from a single material or a plurality of materials, and it goes without saying that it may further contain various additives as long as the intended purpose is not hindered.

Such a dye-receiving layer may be of any thickness.

Generally, the thickness is 5 to 50 #Lm. Although such a dye-receiving layer is preferably a continuous coating, it may also be formed as a discontinuous coating using a resin emulsion or resin dispersion.

Such a transfer material is basically as described above and can be used as is, but it is possible to incorporate an inorganic powder for anti-adhesion into the transfer material or its dye-receiving layer. In this way, even if the temperature during thermal transfer is increased, adhesion between the thermal transfer sheet and the material to be transferred can be prevented, and even better thermal transfer can be performed. Particularly preferred is finely powdered silica.

Furthermore, in place of or in combination with the inorganic powder such as silica, the above-mentioned resin having good mold releasability may be added. Particularly preferred release polymers include cured products of silicone compounds, such as epoxy-modified silicone oil and
Examples include cured products made of mino-modified silicone oil. Such a release agent may be used in an amount of about 0.5 to about 0.5 to about 0.5 of the weight of the dye receiving layer.
A ratio of 30% by weight is good.

In addition, the transfer material used has "
- An inorganic powder as described above may be attached to enhance the anti-adhesive effect, or a layer made of a mold release agent having excellent mold release properties as described above may be provided.

Such a release layer exhibits a sufficient effect at a thickness of about 0.01 to 5) inches to further improve dye receptivity while preventing adhesion to the dye receptive layer of the thermal transfer sheet. be able to.

Any conventionally known means for imparting thermal energy can be used as the means for imparting 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, such as a thermal printer ( For example, by controlling the recording time using a recording device such as a thermal printer TN-5400 manufactured by Toshiba ■,
By applying a thermal energy of about 00 m J/mm', the intended purpose can be fully achieved.

(Operations/Effects) By using the thermal transfer sheet of the present invention as described above, before carrying out a large amount of color printing using various printing methods, especially offset printing methods, the original can be color separated using a color scanner. By connecting this to a thermal transfer recording device equipped with a computer and printing in color, this can be used as a proof print, allowing you to correct the color of printed matter, change the layout, insert symbols, characters, other documents, etc. computer without the need to create or modify versions each time.
It can be finally determined by the above processing. Therefore, by creating the final plate in the state determined in this manner, the complicated proof printing process as in the prior art is greatly simplified.

Next, the above will be explained in more detail with reference to Examples. still,
In the text, parts or percentages are by weight unless otherwise specified.

Example 1 Three kinds of ink compositions for forming a dye-carrying layer having the following compositions were prepared. In the cyan and yellow ink compositions, the components were dissolved and then filtered to remove insoluble matter. A dry coating amount of 1.0 g/r was applied to a 9ti-m thick polyethylene terephthalate film with heat-resistant treatment on the back side of each film.
The cyan of the present invention is coated and dried to achieve rf,
Three-color thermal transfer sheets, magenta and yellow, were obtained.

2ヱヱL Kayaset Blue714
1.00 copies Foron Br1lliant BIue
S-R 4.80 parts (contains dispersant) Polybutyral resin 4.60 parts Methyl ethyl ketone 44.80 parts Toluene
44.80 copies Edan EU MS Red G 2.
Part 8 Part 1 Macrolex Red Violet
R1,58 parts polybutyral resin 4.
32 parts Methyl ethyl ketone 43.34 parts Toluene 42.92 parts Cyclohexanone 5.0 parts Foron Br1lliant Yellow S-
6GL fl, 00 parts (contains dispersant) Polybutyral resin 4.52 parts Methyl ethyl ketone 43.99 parts Toluene
40.99 parts cyclohexanone 4.50 parts Next, synthetic paper (manufactured by Tamago Yuka) was used as a base sheet.

Using Yubo FPG #150), apply a coating liquid with the following composition to one side of the coating at a dry rate of 4.5 g/rr? The transfer material was coated at a ratio of 100° C. and dried at 100° C. for 30 minutes to obtain a transfer material.

Polyester resin (Vylon200, manufactured by Sokushobo) 11
．． 5 parts vinyl chloride-vinyl acetate copolymer (VYHH1U
CC) 5.0 parts Amino-modified silicone oil (KF-393, Shin-Etsu Chemical Acid) 1.2 parts Epoxy-modified silicone oil (X-22-343, Shin-Etsu Chemical) 1.2 parts Methyl ethyl ketone/toluene /cyclohexanone (weight ratio 4
:4:2) 102 parts The three-color thermal transfer sheet of the present invention and the transfer material described above were placed one on top of the other with their respective dye-carrying layers and dye-receiving surfaces facing each other, and a head was applied from the back side of the thermal transfer sheet. Voltage iov, printing time 4
Recording was performed with a thermal head under the conditions of , 0 rssec, and a three-color image was obtained. When the color rendering properties of these three-color images were compared with a proof print image using standard colors of offset printing ink (G Set Ink, manufactured by Moroboshi Ink), good agreement was found.

Example 2 In Example 1, three colors of dye-carrying layer forming inks were used.
A continuous sheet with three colors in the same manner as in Example 1, except that cyan, magenta, and yellow were applied and dried in that order in a fixed area on one continuous sheet (Example 1 and the rotating base material).''
A continuous sheet-shaped thermal transfer sheet for color image formation of the present invention was obtained, in which the color images were arranged in sequence.

Using this thermal transfer sheet, thermal transfer was performed successively in the order of cyan, magenta, and yellow in the same manner as in Example 1 to form a color image. On the other hand, for comparison, a color image was formed from the same document using a proofing machine using standard offset ink (G set ink, manufactured by Moroboshi Ink), and when compared with the color image above, it was impossible to distinguish with the naked eye. The color rendering properties of these two types of color images were as shown in FIG.

[Brief explanation of drawings]

FIG. 1 shows a color image (A
) and the standard offset ink color image (B) using a reflection densitometer (Macbeth RD-918), measure the density with blue-violet, green, and red filters, and calculate these values as GA.
This is a color circle created based on the TF method. Procedural amendments stamped) June 9, 1986

Claims (3)

[Claims] (1) A thermal transfer sheet for color image formation comprising at least three types of thermal transfer sheets each having a dye-carrying layer containing a dye of each hue of cyan, magenta, and yellow, wherein the cyan dye is C.I. I. It is a mixture of Solvent Blue 63 and a dye represented by the following formula (I), and the magenta dye is a mixture of C.I. I. Dispersed Red 60 and C.I. I. A thermal transfer sheet for color image formation, which is a mixture of Disperse Violet 26, and wherein the yellow dye is a dye represented by the following formula (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (2) Thermal transfer sheet for color image formation according to claim (1), wherein the base sheet is one sheet, and dye-supporting layers of three colors are formed on the surface of the base sheet in any order. . (3) The thermal transfer sheet for color image formation according to claim (1), further comprising a thermal transfer sheet having a black dye-supporting layer.