JPS62101495A - Image-receiving sheet for thermal transfer - Google Patents

Abstract

PURPOSE:To enable a hard copy to be formed having images with favorable resolution, high density and a lustrous feeling, by providing an image-receiving layer comprising a sublimable dye receiving resin having a specified thermal deformation temperature and a releasing agent and having a specified surface roughness and a specified surface glossiness, on a base sheet. CONSTITUTION:An image-receiving sheet for thermal transfer comprises an image-receiving layer comprising a sublimable dye receiving resin and a releasing agent on a base sheet, in which the thermal deformation temperature of the resin is not lower than 100 deg.C, the surface roughness of the image-receiving layer is not more than 1mum, and the surface glossiness of the layer is not less than 80%. The resin is selected from, for example, a group consisting of a polycarbonate, a polysulfone, a polyacrylate and the like. The releasing agent, which prevents the image-receiving layer and a dye layer from being welded to each other at the time of recording, is selected from, for example, a group consisting of a silicon compound, a fluorine compound, a higher fatty acid, a metallic salt thereof, a surfactant and the like, and one highly compatible with the resin is preferred. With this image-receiving sheet, a transferred image with favorable resolution, a lustrous feeling and high density can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an image receiving sheet in a thermal transfer recording method.

BACKGROUND OF THE INVENTION Methods for reproducing images in the form of hard copies such as photographs from electrical image signals obtained from video cameras, still video cameras, televisions, video discs, phototransmission devices, etc. are being actively researched.

A thermal transfer image recording method is currently attracting attention as one of the promising methods.

Thermal transfer image recording involves sending an electric signal containing image information to a thermal head in which, for example, 4 to 16 electric heating elements are lined up in a row per crane, and at the same time applying a sublimable dye layer to the surface of a support sheet. ``Die sheet'' and ``
A hard copy is produced by moving a stack of "image-receiving sheets" in contact with a head, thereby transferring the dye from the adhesive sheet to the image-receiving sheet in dots.

However, conventional hard copies have the drawbacks of rough images, low density, and lack of gloss.

(Object of the Invention) An object of the present invention is to provide an image-receiving sheet capable of solving the above-mentioned drawbacks and forming a glossy hard copy with fine-grained, high-density images.

(Summary of the Invention) As a result of intensive research into the causes of the above-mentioned drawbacks, the present inventors found that: (1) Most conventional image-receiving sheets have an image-receiving layer made of a dye-receiving resin on a support sheet; The dye-receiving resin used has a heat deformation temperature of 80°C or lower, so that the image-receiving layer becomes resistant to Dice 1-1 during recording.
In order to prevent this, fillers or release agents are added to the image-receiving layer, and as a result,
In the former case, the surface of the image-receiving layer becomes uneven, resulting in an overall rough image; in the latter case, the low-density areas of the image are glossy, but the high-density areas have a thermally deformed surface. It was discovered that the image does not lose its luster due to the exposure to light, resulting in an overall lackluster image.

In addition, ■The surface of the conventional image-receiving layer has an average roughness (Ra) of 1 μm.
It was found that since the diameter is larger than m, the adhesion with the dye layer surface of the die sheet is poor, and therefore, the heat of the thermal head is not efficiently transferred and a high-density image cannot be obtained.

Furthermore, ■ the surface glossiness of the image-receiving sheet itself (JIS-Z
-8741) is less than 80%, it has been found that a glossy image cannot be obtained.

Therefore, as a result of further research, it was found that: ■ The dye-receptive resin used had a heat deformation temperature of 100°C or higher; ■
If the three requirements of the surface roughness of the image-receiving layer be 1 μm or less and the surface gloss of the image-receiving layer be 80% or more are simultaneously satisfied, then these requirements can be combined to create a book. The inventors have found that the object of the invention can be achieved, and have completed the present invention.

Therefore, the present invention provides an image-receiving sheet for thermal transfer comprising an image-receiving layer containing a sublimable dye-receiving resin and a release agent provided on a support sheet, wherein the heat distortion temperature of the resin is 100°C or higher. , an image-receiving sheet for thermal transfer, characterized in that the image-receiving layer has a surface roughness of 1 μm or less, and a surface gloss of the image-receiving layer is 80% or more.

The sublimable dye-receptive resin used in the present invention can be either a thermosetting resin or a thermoplastic resin, but it must have a heat distortion temperature of 100° C. or higher. In particular, a resin having a heat distortion temperature in the range of 100 to 250°C and having a polar group is preferable. Thus, for example, they are specifically selected from the group consisting of polycarbonates, polysulfones, acetal resins, alkyd resins, allyl resins, urea resins, melamine resins, epoxy resins, phenolic resins, unsaturated polyester resins, polyurethanes, Boaryaryl 1, etc. These resins can be used alone, but several types may be mixed or a copolymer may be used.

The mold release agent in the present invention is selected from, for example, silicon compounds, fluorine compounds, higher fatty acids and their metal salts, surfactants, etc., which prevent the image-receiving layer and the dye layer from adhering during recording. Those having good compatibility with the dye-receiving resin are preferred. This is because if the compatibility is poor, the image-receiving layer becomes non-uniform, the surface loses its luster, and uneven dye transfer occurs, resulting in the inability to obtain clear images.

In the present invention, the release agent is preferably used in an amount of 0.01 to 0.5 parts by weight per 1 part by weight of the dye-receiving resin. 0.
If it is less than 0.01, there is a tendency for fusion with the dye layer;
When the number is more than 5, the density of the transferred image decreases.

The image-receiving sheet of the present invention is produced by applying a coating solution in which a dye-receiving resin and a release agent are dissolved or dispersed in an organic solvent or water onto a support sheet such as a plastic sheet or synthetic paper using a wire bar coater, gravure coater, etc. Obtained by coating and drying. The appropriate thickness of the coating layer is usually 0.5 to 20 μm, preferably 1 to 5 μm.

In particular, in the present invention, the image receiving layer has a surface roughness of 1 μm or less,
Since the surface gloss must be 80% or higher, care must be taken in the application method and material selection.

On the other hand, the "die sheet" used in combination with the image-receiving sheet of the present invention consists of a support sheet and a sublimable dye layer coated thereon, and the sublimable dye layer is It consists of a sex dye and a binder. The sublimable dye is a dye that sublimes or vaporizes at 60° C. or higher, and mainly those used in thermal transfer printing such as disperse dyes and oil-soluble dyes can be used. For example, c, r, disperse yellow 1.3. ．． 8,9,16,41.54゜6
0.77 or 116, etc., 1.4 of C,1, Disperse thread. ．． 9,11,15,17,55゜59.60
．． ．． 73 or 83, C, 1, disperse blue 3. 14. 19. 26. 56°60.64,7
2.99 or 108, etc., C, T.

Solvent Yellow such as 77 or 116, C0■, Solvent Red such as 23.25 or 27, C,1, Solvent Blue 36. Examples include '83 or 105. These dyes can be used alone or in combination.

As the binder, thermoplastic or thermosetting resin is used,
For example, vinyl chloride JIF+, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, fluorine resin, butyral resin, melamine resin, natural rubber, synthetic rubber. , polyvinyl alcohol, and cellulose resin ring Lf. These resins can be used alone, but several types may be mixed or a copolymer may be used. To form a sublimable dye layer on a support sheet,
A coating solution may be prepared by dissolving or dispersing a sublimable dye, a binder, and, if necessary, a heat-fusible substance in a solvent or water, and this may be coated using a wire bar coater, air knife coater, gravure coater, etc., and dried. The thickness of the sublimable dye layer is usually 0.1 to 20 μm, preferably 1 to 5 μm.

Furthermore, a heat-resistant layer may be provided on the opposite side of the dye sheet to the sublimable dye layer (that is, on the back side) in order to prevent fusion between the thermal head and the support sheet. For example, a heat-resistant layer is formed by applying a coating solution containing a heat-resistant resin such as silicone resin or fluororesin, or a thermosetting resin such as polyurethane, epoxy resin, phenolic resin, or amino resin dissolved in a solvent to the back of the support sheet and drying it. can get. Furthermore, the heat-resistant layer includes silica powder,
It may contain talc powder, metal powder, wax, etc.
The thickness of the heat-resistant layer is 0.01 to 5 mm, preferably 0.01 mm.
A suitable thickness is 1 to 1 μm.

Hereinafter, the present invention will be specifically explained with reference to Examples.

(Example 1) +l) Production of image-receiving sheet Polyurethane resin 50 parts by weight Tuboran 3110; heat distortion temperature 100°C or higher manufactured by Nippon Polyurethane) Hardening agent 10 parts by weight (Coronate 1 manufactured by Nippon Polyurethane) Silicone oil
A coating solution consisting of 39 parts by weight of ethyl acetate (SF-841'L; manufactured by Resilicone) was applied to synthetic paper (SF-841'L; ) using a wire bar.
It was coated onto a support sheet) and thermally cured at 100° C. for 5 hours to produce an image-receiving sheet with an image-receiving layer surface average roughness (Ra) of 0.3 μm and surface gloss of 95%.

(2) Manufacture of Guisheet Sublimable dye = 5 parts by weight (C, I
, Disperse Red60) Ethyl cellulose: 5 parts by weight methyl ethyl ketone
=90 parts by weight of the composition was dispersed in a ball mill for 20 hours, and then coated on a 6 μm polyester film (support sheet) using a wire bar to form a 1 μm thick sublimable dye layer.

Next, a heat-resistant layer with a thickness of 0.5μ is placed on the opposite side of the sublimation dye layer.
A silicone resin layer of m was provided.

(3) Thermal transfer recording The sublimable dye layer of the die sheet and the image-receiving layer of the image-receiving sheet are superimposed, and the thermal head (0
, 2 W/dat), and thermal transfer recording was performed by varying the application time.

(Comparative Example 1) On the other hand, for comparison, 20 parts by weight of polyester resin, 0.5 parts by weight of silicone oil (byron-200; manufactured by Toyobo, heat distortion temperature: 65°C),
-8417; manufactured by Toray Silicone) Coating a coating solution consisting of 79.5 parts by weight of methyl ethyl ketone on synthetic paper (support sheet) using a wire bar,
The film was dried by heating at 100° C. for 2 hours to produce an image-receiving sheet with an image-receiving layer surface average roughness (Ra) of 0.2 μm and surface gloss of 90%.

Then, thermal transfer recording was performed in the same manner as in Example 1 using this image-receiving sheet.

After observing with the naked eye the surface condition and image quality of the hard copies (image receiving sheets on which red images were recorded) obtained by thermal transfer recording in Example 1 and Comparative Example 1,
Image density is measured using a densitometer (product name: Sakushi PDA-
65), and the results are shown in Tables 1 and 2.

Table 1 (Surface condition/image quality) Table 2 (Image density) Example 2 Polycarbonate 10 parts by weight (Panlite L-1225; heat distortion temperature 135°C, manufactured by Teijin Kasei) Silicone oil 0.5 parts by weight (X-
22-343; Shin-Etsu Silicone) Methylene chloride
89.5 parts by weight of the composition solution was applied onto synthetic paper (support sheet) using a wire bar, and heated at 100°C.
After heating and drying for 2 hours, the average roughness of the surface of the image receiving layer (Ra)
An image receiving sheet with a surface gloss of 0.2 μm and a surface gloss of 90% was produced.

Next, thermal transfer recording was performed using the same die sheet as in Example 1, and an image density of 1.58 was obtained with an application time of 10 m5ec, and the image was clear without loss of gloss on the surface of the image-receiving layer.

Example 3 In the same manner as in Example 2, except that the polycarbonate was replaced with polyarylate CP-3001 (manufactured by Unitika) with a heat distortion temperature of 160°C), the average roughness of the surface of the image receiving layer (Ra) was changed.
An image receiving sheet with a surface gloss of 85% and a surface gloss of 0.4 μm was produced.

Then, when thermal transfer recording was performed using this image receiving sheet in the same manner as in Example 1, the image density was 1.
No. 49 was obtained, and the surface of the image-receiving layer did not lose its gloss and the image was clear.

(Effects of the Invention) As described above, according to the image-receiving sheet of the present invention, a high-density transferred image that is fine, clear, and glossy can be obtained.

Claims (1)

[Scope of Claims] An image-receiving sheet for thermal transfer comprising an image-receiving layer containing a sublimable dye-receptive resin and a release agent provided on a support sheet, wherein the resin has a heat distortion temperature of 100°C or higher, An image-receiving sheet for thermal transfer, characterized in that the image-receiving layer has a surface roughness of 1 μm or less and a surface gloss of 80% or more.