JP2622675B2 - Heat transfer sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet to be heat-transferred, and more particularly, to an image recording method in which a sublimation dye in a color material layer of a heat transfer sheet is heat-transferred according to image information. The present invention relates to a heat transfer sheet.

[Conventional technology]

In recent years, as a recording method for recording an image such as a photograph directly from an image on a CRT display, the thermal transfer sheet is heated by a thermal head or the like whose heat is controlled by an electric signal, and sublimation in a color material layer of the thermal transfer sheet is performed. A thermal transfer recording system has been adopted in which a dye is transferred onto a transfer-receiving sheet to record image information. This thermal transfer recording method has attracted attention as a method capable of transferring and recording a color image having a continuous change in color density by performing superimposed recording of cyan, magenta, and yellow. As the heat transfer sheet used in the thermal transfer recording method, conventionally, a sheet in which a polyether resin is applied to the surface of a base material and an image receiving layer to which a sublimable dye is transferred is formed.

[Problems to be solved by the invention]

However, the heat transfer sheet of the related art has a drawback that the transferred image has poor light fastness, reduces the sharpness of the transferred image during storage, and cannot maintain a beautiful image for a long period of time. This is considered to be because the dye is easily transferred to the vicinity of the surface of the image receiving layer of the heat transfer sheet in the sublimation transfer method in which the dye is sublimated and transferred by applying energy in a short time by the thermal head. .

[Means for solving the problem]

The present inventors have conducted intensive research to solve the above problems, and as a result, the image receiving layer is composed of a styrene-based resin or a resin mixture containing at least a styrene-based resin, using a specific base material, and further including the image-receiving layer. It has been found that when a cushion layer is provided between the substrate and the base material, the light resistance can be remarkably improved, and the present invention has been completed.

That is, the present invention includes: (1) an image receiving layer in which a sublimable dye in a color material layer of a thermal transfer sheet is heated and transferred to record in accordance with image information, and a base material on which the image receiving layer is carried In the heat transfer sheet, a styrene-based resin or a resin mixture containing at least a styrene-based resin is used as the image-receiving layer constituting resin, and a synthetic paper having microvoids is used as the base material. (2) The heat transfer sheet according to the above (1), wherein the resin constituting the image receiving layer is a styrene homopolymer, and (3) the resin constituting the image receiving layer is α-. (1) The heat transfer sheet according to the above (1), which is a copolymer of methylstyrene and vinyltoluene; (5) The heat transfer sheet according to (1) above, wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer and an acrylic monomer. (6) The resin constituting the image receiving layer is a styrene monomer. Transfer sheet according to the above (1), which is a copolymer of styrene and acrylonitrile; (7) the heat transfer sheet according to the above (1), wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer and maleic anhydride. (8) the heat receiving sheet according to the above (1), wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer, an acrylic ester and acrylamide; (9) the resin comprising the image receiving layer is a styrene homopolymer;
copolymer of α-methylstyrene and vinyltoluene, α
A copolymer of methylstyrene and styrene, a copolymer of styrene monomer and acrylic monomer, a copolymer of styrene monomer and acrylonitrile, a copolymer of styrene monomer and maleic anhydride, styrene (1) The heat transfer sheet according to the above (1), wherein a mixed resin of at least two or more of a copolymer of a monomer, an acrylic ester and an acrylamide is used, (10) a resin constituting the image receiving layer is a vinyl chloride-vinyl acetate copolymer A heat transfer sheet according to the above (1), which is a mixture of at least one resin selected from the group consisting of polymethacrylate, polyacrylate, and cellulose acetobutyrate, and a styrene-based resin; (1) containing a reaction product of an amino-modified silicone and an epoxy-modified silicone as a release agent therein. (12) The heat transfer sheet according to any one of (1) to (11) above, wherein a release agent layer is provided on a part or the entire surface of the image receiving layer. (13) The heat-receiving sheet according to the above (12), wherein the release agent layer is obtained by reacting an amino-modified silicone and an epoxy-modified silicone. (14) The above-mentioned (12), wherein the release agent layer comprises a catalyst-curable silicone. (15) Titanium oxide, zinc oxide, kaolin,
One or more selected from the group consisting of clay,
The heat transfer sheet according to any one of the above (1) to (14), wherein 5 to 20 parts by weight is contained with respect to 100 parts by weight of the resin.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a heat transfer sheet 1 according to the present invention. The heat transfer sheet 1 comprises a base material 2, an image receiving layer 3, and a cushion provided between the image receiving layer 3 and the base material 2. And a layer 5.

As the substrate 2, synthetic paper having microvoids is used.

The thickness of the substrate 2 is usually 50 to 400 μm, particularly 70 to 170 μm.
μm is preferred.

In the present invention, the image receiving layer 3 is composed of a styrene resin or a resin mixture containing at least a styrene resin.

Examples of the styrene resin include a styrene homopolymer, a copolymer of α-methylstyrene and vinyltoluene, a copolymer of α-methylstyrene and styrene, a copolymer of a styrene monomer and an acrylic monomer, Examples include a copolymer of a styrene monomer and acrylonitrile, a copolymer of a styrene monomer and maleic anhydride, and a copolymer of a styrene monomer, acrylic ester and acrylamide.

Some specific examples of the styrene-based resin include Hymer SBM-100, Hymer SBM-73F, Hymer SAM-955 (all styrene-acrylic, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), KA
1039-S (Styrene-acrylic type, Arakawa Chemical Co., Ltd.)
RMD-4511 (styrene-acrylonitrile-based, UCC
TYRIL-767 (styrene-acrylonitrile, Do
w company), CYMAC100 (styrene-acrylonitrile, A
CC) and Oxylac SH-101 (styrene-maleic acid copolymer resin, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.).

The above styrene resins can be used alone or in combination of two or more.

In the present invention, it is also possible to use a mixture of the styrene resin and another resin as the resin constituting the image receiving layer.

As a resin used by mixing with the styrene resin,
For example, vinyl chloride-vinyl acetate copolymer, polymethacrylate, polyacrylate, cellulose acetobutyrate and the like can be mentioned.

A mixture of one or more of these resins and a styrene-based resin can be used. The mixing ratio of the styrene resin to the other resin is about 100 to 900 parts by weight based on 100 parts by weight of the styrene resin.

By mixing styrene-based resin and vinyl chloride-vinyl acetate copolymer-based resin, improvement of coating properness,
There are advantages such as improvement of physical properties (improvement of flexibility) of the film. Specific examples of the vinyl chloride-vinyl acetate copolymer include VYHH, VMC
H (manufactured by UCC) and the like.

Further, by mixing the polyester resin, there are advantages such as improvement in dyeing properties of dyes and improvement in coating suitability. Specific examples of the polyester resin include Vylon200 (manufactured by Toyobo),
TP200, TP235 (manufactured by Nippon Gosei) and the like.

In the present invention, the image receiving layer 3 is used for the purpose of improving the whiteness of the image receiving layer 3 to further enhance the sharpness of the transferred image, imparting writability to the surface of the heat transfer sheet, and preventing retransfer of the transferred image. A white pigment can be added therein. Further, by adding a white pigment, transfer of an image having higher clarity and excellent heat resistance and moisture resistance can be performed.

As the white pigment, titanium oxide, zinc oxide, kaolin clay and the like are used, and these can be used in combination of two or more. As the titanium oxide, anatase-type titanium oxide and rutile-type titanium oxide can be used.As the anatase-type titanium oxide, for example, KA-10, KA-15, and KA
-20, KA-30, KA-30, KA-60, KA-80, KA-90 (all manufactured by Titanium Industry Co., Ltd.), KR as rutile titanium oxide
-310, KR-380, KR-460, KR-480 (all manufactured by Titanium Industry Co., Ltd.). The addition amount of the white pigment is preferably 5 to 50 parts by weight based on 100 parts by weight of the resin constituting the image receiving layer 3.

In the present invention, an ultraviolet absorber may be added to the image receiving layer 3. By adding an ultraviolet absorber, the light fastness of the dyed dye is further improved. As the ultraviolet absorber, benzophenone type, hindered amine type,
Benzotriazoles and the like can be mentioned. The addition amount is about 0.05 to 5 parts by weight based on 100 parts by weight of the resin constituting the image receiving layer 3.

The heat transfer sheet 1 of the present invention is provided with a cushion layer 5 between the substrate 2 and the image receiving layer 3 as shown in FIG. As a material constituting the cushion layer 5, for example, urethane resin,
Acrylic resin, ethylene resin, butadiene rubber, epoxy resin and the like can be mentioned. The thickness of the cushion layer is 2-20
It is preferably about μm. By providing such a cushion layer 5, an image corresponding to image information with few nozzles can be transferred and recorded with good reproducibility.

The heat transfer sheet 1 of the present invention can contain a release agent in the image receiving layer 3 in order to improve the releasability from the heat transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphate-based surfactants; silicone oil; and the like, but silicone oil is preferred.

As the silicone oil, an oily oil can be used, but a curable oil is 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. As the reaction-curable silicone oil, those obtained by reacting and curing an amino-modified silicone oil and an epoxy-modified silicone oil are preferable. As the amino-modified silicone oil, KF-393, KF-857, and KF-85 are preferable.
8, X-22-3680, X-22-3801C (manufactured by Shin-Etsu Chemical Co., Ltd.)
And epoxy-modified silicone oils such as KF-100T, KF-101, KF-60-164, and KF-103 (manufactured by Shin-Etsu Chemical Co., Ltd.). KS-705F-PS, KS as catalyst-curable or photocurable silicone oil
-705F-PS-1, KS-770-PL-3 (catalyst-curable silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.), KS-720, KS
-774-PL-3 (above, photocurable silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.). The addition amount of these curable silicone oils depends on the amount of resin 100 constituting the image receiving layer 3.
It is preferably 0.5 to 30 parts by weight based on parts by weight.

Further, as shown in FIG. 2, the release agent layer 4 may be provided on a part of the surface of the image receiving layer 3 by dissolving or dispersing the release agent in an appropriate solvent and applying it, followed by drying. it can. The release agent constituting the release agent layer 4 is particularly preferably a cured product of the above-mentioned amino-modified silicone oil and epoxy-modified silicone oil. The thickness of the release agent layer 4 is preferably 0.01 to 5 μm, particularly preferably 0.05 to 2 μm. The release agent layer 4 may be provided on a part of the surface of the image receiving layer 3 as shown in FIG. 2 or may be provided on the entire surface. Dot impact recording, heat-sensitive melt transfer recording, and recording with a pencil or the like can be performed on the portion where the release agent layer 4 is not provided, and sublimation transfer recording is performed on the portion where the release agent layer 4 is provided. Sublimation transfer recording and other recording methods can be performed together, for example, recording is performed on a portion not provided by another recording method.

Further, a lubricating layer can be provided on the back surface of the substrate. In some cases, the heat transfer sheets are stacked and fed one by one to perform the transfer. In this case, if a slip layer is provided, the slip between the sheets becomes smooth, and the sheets can be fed accurately one by one. Examples of the material of the lubricating layer include a methacrylate resin such as methyl methacrylate or a corresponding acrylate resin, and a vinyl resin such as a vinyl chloride-vinyl acetate copolymer.

Further, an antistatic agent can be contained in the heat transfer sheet. By incorporating an antistatic agent, the sliding between the sheets can be made smoother,
This has the effect of preventing dust from adhering to the heat transfer sheet.
The antistatic agent may be contained in the substrate or the image receiving layer, or may be provided as an antistatic agent layer on the back surface of the substrate or the like, but is preferably provided on the back surface of the substrate as the antistatic layer.

In the present invention, it is also possible to provide a detection mark on the heat transfer sheet. The detection mark is extremely convenient when positioning the heat transfer sheet and the heat transfer target sheet.
For example, a detection mark that can be detected by the photoelectric tube detection device can be provided on the back surface of the base material by printing or the like.

The heat transfer sheet 1 of the present invention having the above-described configuration is superimposed on the heat transfer sheet 6 such that the color material layer 7 of the heat transfer sheet 6 and the image receiving layer 3 of the heat transfer sheet 1 are in contact with each other as shown in FIG. After the thermal transfer sheet 6 is heated from the support member 8 side by a thermal head or the like, the transfer sheet 6 is peeled off, whereby the sublimable dye in the color material layer 7 is transferred to the image receiving layer 3 of the heat transfer sheet 1 and heat transfer is performed. An image corresponding to the image information is recorded on the sheet 1. Examples of the sublimable dye used for the thermal transfer sheet 6 include relatively low molecular weight disperse dyes having a molecular weight of about 150 to 600, oil dyes, certain basic dyes, and intermediates which can be changed to these dyes. These sublimable dyes are selected and used in consideration of thermal transfer temperature, thermal transfer efficiency, hue, color rendering, weather resistance and the like.
The color material phase 7 of the thermal transfer sheet 6 is formed by, for example, dispersing the above-described sublimable dye in a synthetic resin binder and applying it to the surface of the support material 8. Examples of such a synthetic resin binder include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose acetate butyrate; polyvinyl alcohol, polyvinyl butyral, and polyvinylpyrrolidone;
Examples thereof include vinyl resins such as polyester, polyvinyl acetate, and polyacrylamide. Among these resins, polyvinyl butyral having excellent acid resistance or a cellulose resin is preferable. Examples of the support material 8 of the thermal transfer sheet 6 include a polyester film, a polystyrene film, a polysulfone film, a polyvinyl alcohol film, a cellophane film, and the like, and a polyester film is particularly preferable in terms of heat resistance. The thickness of the support member 8 is preferably 0.5 to 50 μm, particularly preferably 3 to 10 μm.

The thermal transfer sheet 6 is heated from the support member 8 side by a heating means such as a thermal head. It is preferable to provide a lubricating layer containing a lubricant such as wax or a release agent on the heated surface of the support member 8. Thus, it is possible to prevent fusion between the heating means and the support member 8.

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

Example 1 A 6 μm-thick polyethylene terephthalate film (S-PET manufactured by Toyobo Co., Ltd.) having one surface subjected to corona discharge treatment was used as a support material, and the color of the following composition was formed on the corona discharge-treated surface of the support material. The material phase composition is applied by wire bar coating so that the thickness when dried becomes 1 μm to form a color material layer, and a silicone oil (X-41-4003A:
After dropping two drops of the product (made by Shin-Etsu Silicone Co., Ltd.) with a dropper, it was spread over the entire surface to form a lubricating layer to obtain a thermal transfer sheet.

Color material layer composition Disperse dye (manufactured by Nippon Kayaku: Kayaset Blue 136) 4 parts by weight Ethyl hydroxyethyl cellulose (manufactured by Hercules) 5 parts by weight Toluene 40 parts by weight Methyl ethyl ketone 40 parts by weight Dioxane 10 parts by weight On the other hand, synthetic paper of 150 μm (Oji Yuka: YUPO-FPG-15
0) as a base material, and the thickness of the cushion layer composition having the following composition when dried by wire bar coating on this surface.
It was applied to a thickness of 10 μm and dried to form a cushion layer.

Cushion layer composition Elvaloy 742 (ethylene resin: Tg = -32 ° C) 15.0 parts by weight Toluene 42.5 parts by weight Methyl ethyl ketone 42.5 parts by weight Next, the image receiving layer composition having the following composition was dried on the surface of the cushion layer by wire bar coating. Thickness 4
μm, and temporarily dry with a drier.
The resultant was dried in an oven at a temperature of 30 ° C. for 30 minutes to form an image receiving layer, thereby obtaining a heat transfer sheet.

Image receiving layer composition Hymer SBM100 (Mitsubishi Chemical: styrene-acrylic copolymer) 14 parts by weight KF-393 (Shin-Etsu Silicone: Amino-modified silicone oil) 1 part by weight X-22-343 (Shin-Etsu Silicone: Epoxy-modified silicone oil) 1 part by weight Toluene 42 parts by weight Methyl ethyl ketone 42 parts by weight The above-mentioned thermal transfer sheet and the thermally stopped sheet are overlapped so that the color material layer and the image receiving layer are in contact with each other. Output
Heated at 1 W / dot, pulse width 0.3 to 0.45 m / sec, dot density 3 dot / mm, and transferred the cyan disperse dye in the color material layer of the thermal transfer sheet to the image receiving layer of the thermal transfer sheet. A cyan image was transferred.

Next, a light fastness test of the image transferred to the heat transfer sheet was performed under the following conditions. As a result of measuring the fading rate of the image after the light resistance test, the fading rate was 91%.

Light fastness test Exposure was performed for 10 hours under the conditions based on JIS L0842.

The fading rate is represented by a percentage obtained by measuring the image density immediately after printing and the image density after testing with a Macbeth reflection densitometer (RD-918), and dividing the image density after testing by the image density immediately after printing.

Comparative Example 1 Vylon 200 (Toyobo polyester: Tg = 67 ° C.) was used in place of the styrene copolymer on the same base material as in Example 1, and the other composition contents were the same as those in Example 1. Thickness of 5μm when dried by wire bar coating
And dried to obtain a heat transfer sheet.

Using the same thermal transfer sheet as in Example 1, transfer was performed on this thermal transfer sheet under the same conditions. Next, a light fastness test of this heat transfer sheet was performed under the same conditions as in Example 1.
As a result of measuring the fading rate after the light resistance test, the fading rate was 50%.

〔The invention's effect〕

As described above, the heat-receiving sheet of the present invention is such that the image receiving layer to which the sublimable dye in the coloring material layer of the thermal transfer sheet is transferred is made of a styrene-based resin or a mixed resin containing at least a styrene-based resin, By using a synthetic paper having microvoids as a base material and further providing a cushion layer between the image receiving layer and the base material, the image transferred to the image receiving layer has excellent light resistance, and the transferred image is excellent. Has a variety of effects, such as a very small decrease in color and the ability to maintain image clarity almost equal to that immediately after transfer for a long period of time.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention in the drawings, FIG. 1 is a longitudinal sectional view showing one embodiment of the heat transfer sheet of the present invention, FIG. 2 is a longitudinal sectional view showing another embodiment of the heat transfer sheet of the present invention, FIG. FIG. 3 is a longitudinal sectional view showing a state in which the heat transfer sheet and the heat transfer sheet are overlapped and the sublimable dye of the heat transfer sheet is transferred to the heat transfer sheet. DESCRIPTION OF SYMBOLS 1 ... Heat transfer sheet 2 ... Base material 3 ... Image receiving layer 4 ... Release layer 5 ... Cushion layer

Claims (15)

(57) [Claims] 1. A heat transfer sheet having an image receiving layer on which a sublimable dye in a color material layer of a thermal transfer sheet is transferred by heating to record according to image information, and a base material on which the image receiving layer is carried. Using a styrene-based resin or a resin mixture containing at least a styrene-based resin as an image-receiving layer constituting resin, using a synthetic paper having microvoids as a substrate, and further forming a cushion layer between the image-receiving layer and the substrate. A heat transfer sheet characterized by being provided. 2. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a styrene homopolymer. 3. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of α-methylstyrene and vinyltoluene. 4. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of α-methylstyrene and styrene. 5. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer and an acrylic monomer. 6. The method according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer and acrylonitrile.
Item. 7. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer and maleic anhydride. 8. The heat transfer sheet according to claim 1, wherein the resin constituting the image receiving layer is a copolymer of a styrene monomer, acrylic ester and acrylamide. 9. An image-receiving layer comprising a styrene-based homopolymer, a copolymer of α-methylstyrene and vinyltoluene, a copolymer of α-methylstyrene and styrene, or a copolymer of styrene-based monomer and acrylic-based monomer. Mixed resin of at least two of copolymer, copolymer of styrene monomer and acrylonitrile, copolymer of styrene monomer and maleic anhydride, copolymer of styrene monomer, acrylic ester and acrylamide 2. The heat-transferable sheet according to claim 1, wherein said sheet is used. 10. A resin comprising at least one resin selected from the group consisting of vinyl chloride-vinyl acetate copolymer, polymethacrylate, polyacrylate, and cellulose acetobutyrate, and a styrene resin. 2. The heat-transferable sheet according to claim 1, which is a mixture of the following. 11. The heat transfer sheet according to claim 1, wherein the image receiving layer contains a reaction product of an amino-modified silicone and an epoxy-modified silicone as a release agent. 12. The heat transfer sheet according to claim 1, wherein a release agent layer is provided on a part or the entire surface of the image receiving layer. 13. The heat transfer sheet according to claim 12, wherein the release agent layer is obtained by reacting an amino-modified silicone and an epoxy-modified silicone. 14. The heat transfer sheet according to claim 12, wherein the release agent layer is made of catalyst-curable silicone. 15. An image receiving layer comprising 5 to 20 parts by weight of one or more selected from the group consisting of titanium oxide, zinc oxide, kaolin and clay based on 100 parts by weight of the resin. Item 15. The heat transfer sheet according to any one of Items 1 to 14.