JPH0789247A - Sublimable thermal transfer medium and recording - Google Patents

Abstract

PURPOSE:To obtain a sublimable thermal transfer medium which is free from the missing of dots in a low density part by preventing the medium from becoming fused to a thermal head due to its heat and also inhibiting the generation of a sticking phenomenon. CONSTITUTION:This sublimable thermal transfer medium consists of a sublimable thermal transfer layer containing a sublimable dye and a resin binder provided on one side of a basic sheet and a heat-resistant layer containing a lubricant and a resin binder on the other side of the basic sheet. In this medium, the lubricant is formed into a particle or an aggregate in the heat-resistant layer, and the height of a part protruding from the surface of the heat-resistant layer of the particle or the aggregate is 1/50 or more and 1/2 or less the thickness of the basic sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer medium, particularly a sublimation type thermal transfer medium used for color recording in OA terminals such as copiers, facsimiles and printers and color recording of CRT images in televisions, computers and the like. Regarding

[0002]

2. Description of the Related Art In recent years, a sublimation type thermal transfer recording method has been developed to obtain a color image easily and at high speed, excellent continuous tone and a silver salt photographic-like full color image. . The sublimation type thermal transfer medium used in this recording method has a sublimable thermal transfer layer containing a sublimation dye and a resin binder formed on one surface of a base material sheet such as a PET film, and a heat from a thermal head on the other surface of the base material sheet. A heat-resistant layer containing a lubricant and a resin binder is formed in order to prevent fusion due to. There have been many proposals for this heat-resistant layer, including a heat-melt type thermal transfer recording medium.
That is, a heat-resistant layer comprising a heat-resistant resin binder (Japanese Patent Laid-Open No. 55-7467), a method for improving the heat-resistant layer is to add heat-resistant fine particles, a lubricant, a surfactant, etc., The particle size is defined, and further, the particle size is defined in comparison with the thickness of the heat-resistant layer (JP-A-56-155794, JP-A-61-1499).
2, JP-A-63-145088, JP-A-3-4228
7, JP-A-3-65396).

[0003]

However, in the recent sublimation type thermal transfer recording method, higher energy is required at the time of recording as compared with the heat melting type, so that the structure of the heat-resistant layer proposed hitherto has sufficient effect. If the sublimation type thermal transfer medium (hereinafter also referred to as a transfer medium) does not run smoothly due to fusion, the transfer medium is damaged during printing, or sticking unevenness occurs even if printing is possible. When fine particles are added to the heat-resistant layer, if the fine particles are too small, irregularities cannot be formed on the surface of the heat-resistant layer, and the effect of preventing fusion is hardly expected. On the other hand, even if the fine particles are sufficiently large and unevenness is formed on the surface of the heat-resistant layer to exert the effect of preventing fusion, another problem of dot omission occurs at the low density portion. This dot dropout in the low density portion is magnified to n times when recording the transfer medium transport speed at 1 / n (n> 1) of the image receiver transport speed (also referred to as speed difference mode recording), and is remarkable. This causes deterioration of image quality.

An object of the present invention is to provide a sublimation type thermal transfer transfer medium which can obtain an image free from sticking due to heat from a thermal head and free from sticking unevenness and missing dots in a low density portion, and the transfer medium. It is an object of the present invention to provide a recording method capable of exhibiting the above effect even if the recording speed is 1 / n (n> 1) of the image carrier speed.

[0005]

According to the present invention, firstly, a sublimable thermal transfer layer containing a sublimable dye and a resin binder is provided on one surface of a base sheet, and the other surface of the base sheet is provided. In a sublimation type thermal transfer medium provided with a heat resistant layer containing a lubricant and a resin binder, the heat resistant layer is formed by a lubricant composed of particles or aggregates, and the particles or aggregates protrude from the surface of the heat resistant layer. Provided is a sublimation type thermal transfer medium in which the height of the protruding portion is 1/50 or more and 1/2 or less of the thickness of the substrate sheet. Secondly, there is provided a sublimation type thermal transfer transfer medium in which the resin binder of the heat resistant layer is a curable phosphazene compound. Furthermore, thirdly, using the first or second sublimation type thermal transfer medium, the transfer speed of the transfer medium is 1 / n (n> n) of the transfer speed of the image receptor.
A sublimation type thermal transfer recording method for performing recording in 1) is provided.

The sublimation type thermal transfer medium of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a base sheet, 2
Is a sublimable thermal transfer layer, and 3 is a heat resistant layer. As the base material sheet 1, a polyester film, a polysulfone film, a polystyrene film, an aramid film, a polyarylate film, a polyethylene naphthalate film, or the like is used. Its thickness is 0.5 to 20 μm, preferably 3 to 10 μm.

The sublimable thermal transfer layer 2 is formed of at least a sublimable dye and a resin binder, and the sublimable dye is a dye that sublimes or vaporizes at 60 ° C. or higher, and is mainly a thermal transfer printing such as a disperse dye or an oil-soluble dye. Any of those used in C.I. I. Disperse Yellow 1, 3, 8, 9, 16, 41, 54, 60, 77, 1
16, etc., C.I. I. Disperse Red 1, 4, 6,
11, 15, 17, 55, 59, 60, 73, 83, C.I. I. Disperse Blue 3, 14, 19, 2
6, 56, 60, 64, 72, 99, 108, etc., C.I.
I. Solvent Yellow 77, 116, C.I. I.
Solvent Red 23, 25, 27, etc., such as C.I. I. Solvent Blue 36, 83, 105 etc. are mentioned,
These dyes may be used alone or in combination of several kinds.

A thermoplastic or thermosetting resin is used as the resin binder, and as the resin having a relatively high glass transition point or high softening property, for example, vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene,
Examples thereof include polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, fluororesin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, and cellulose resin.
One of these resins may be used, or several of them may be used, or a copolymer may be used.

In order to form the sublimable thermal transfer layer 2, the sublimation dye and the resin binder are dispersed or dissolved in a solvent and coated on the substrate sheet 1 using a coating device such as a gravure coater and dried. The sublimable thermal transfer layer 2
Any additive may be added to. Moreover, you may provide an intermediate | middle layer between the base material sheet 1 and the sublimable heat transfer layer 2 as needed.

The heat resistant layer 3 is formed of at least a lubricant and a resin binder. As the lubricant, one that forms particles or aggregates in the heat-resistant layer 3, for example, graphite,
Carbon black, molybdenum disulfide, silica, alumina, titanium oxide, zinc oxide, calcium carbonate, aluminum carbonate, zinc stearate, polyvalent metal salts of alkyl phosphates, alkali metal salts of phosphates, alkalis of phosphates Earth metal salts, fluorinated carbon, melamine resin crosslinked powder, acrylic resin crosslinked powder, styrene / acrylic resin crosslinked powder, amino resin crosslinked powder, silicone powder,
Teflon powder or the like is used.

Examples of the resin binder include thermoplastic resins having various heat resistances, thermosetting resins, radiation curable resins and the like. In particular, cellulosic resins such as ethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and cellulose acetate, polyvinyl butyral, polyvinyl alcohol, vinyl resins such as polyvinyl acetal, polyurethane resins, silicone-modified urethane resins, polyester resins (these resins are isocyanates as crosslinking agents. And the like), and a radiation polymer such as an acryloyl group or a methacryloyl group, more preferably a radiation curable resin such as a curable phosphazene compound.

The method for preparing the coating liquid used when forming the heat-resistant layer 3 is as follows:
It is prepared using a dispersing means such as a main roll or a ball mill. At this time, additives can be added if necessary. As a coating method, a gravure coater, a wire bar coater, a reverse roll coater or the like is used to coat and dry the base material sheet 1. When using a thermosetting resin, aging treatment is further performed. When a radiation curable resin is used, it is cured by irradiation with radiation.

Next, the height of the portion of the lubricant particles or agglomerates protruding from the heat-resistant layer is set to 1/50 or more and 1/2 or less of the thickness of the base sheet. As such a method, a particle diameter of the lubricant particles may be appropriately selected, or a heat resistant layer containing no lubricant may be laminated on the heat resistant layer containing lubricant. Further, in order to cause the lubricant aggregate to protrude from the surface of the heat-resistant layer, a combination of a lubricant and a resin binder is appropriately selected, a dispersion degree is adjusted, a lubricant particle size is appropriately selected, or a lubricant is included. It can be realized by laminating a heat-resistant layer that does not exist.

If the height of the portion of the lubricant particles or agglomerates protruding from the surface of the heat-resistant layer is less than 1/50 of the thickness of the base sheet, fusion occurs, causing poor running and damage to the transfer medium. On the other hand, if it exceeds 1/2, missing dots in the low density portion and stick unevenness in the image density portion occur, and the intended purpose of the present invention cannot be achieved.

[0015]

EXAMPLES The present invention will be described in more detail below with reference to examples. "Parts" in the examples are by weight.

Example 1 <Heat-resistant layer coating liquid> Teflon powder (MP 1100 manufactured by DU PONT, average particle size 3 μm) 3 parts Polyvinyl butyral (BX-1 manufactured by Sekisui Chemical Co., Ltd.) 10 parts Diisocyanate (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) 5 parts Toluene 100 parts Methyl ethyl ketone 100 parts A heat-resistant layer coating solution having the above composition was dispersed and prepared by a ball mill, applied on a 6 μm-thick aramid film with a wire bar, dried with hot air, and further heated in an atmosphere of 60 ° C. Aged for 24 hours. The film thickness of the obtained heat-resistant layer was 1 μm, the Teflon powder formed particles in the heat-resistant layer, and the height of the portion of the particles protruding from the surface of the heat-resistant layer was measured with a laser microscope (1LM21W manufactured by Lasertec). However, it was 2 μm (1/3 of the thickness of the base sheet). Next, a sublimable heat transfer layer coating liquid having the following composition is prepared, coated on a surface opposite to the heat resistant layer using a wire bar, dried with hot air, and then yellow, followed by magenta and cyan sublimable heat transfer layers. Then, a sublimation type thermal transfer transfer medium was produced. The film thickness of each sublimable thermal transfer layer was 1 μm. <Sublimation heat transfer layer coating liquid> Yellow heat transfer dye (YELLOW VP manufactured by Mitsui Toatsu Dye Co., Ltd.) 10 parts (Magenta heat transfer dye (MAGENNTA VP manufactured by Mitsui Toatsu Dye Co., Ltd.) 10 parts) (Cyan heat transfer dye) (Cyan VP manufactured by Mitsui Toatsu Dye Co., Ltd. 10 parts) Polyvinyl butyral (BX-1 manufactured by Sekisui Chemical Co., Ltd.) 10 parts Toluene 100 parts Methyl ethyl ketone 100 parts <Image Receptor> An image receiving layer having the following composition on a synthetic paper of 180 μm as a base sheet. After applying the coating liquid using a wire bar, it was dried with hot air to prepare an image receptor. Polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) 15 parts Toluene 100 parts Methyl ethyl ketone 100 parts The sublimation type thermal transfer transfer medium and the image receptor prepared as described above are mounted on a printer having a line thermal head with a thermal head resolution of 12 dots / mm. When recording was carried out, fusion due to heat from the thermal head did not occur, and the transfer medium ran smoothly. Also, an image without missing dots in the low density portion was obtained. However, some sticking unevenness occurred in the high density area of the image.

Comparative Example 1 Teflon powder of the heat-resistant layer coating liquid in Example 1 was changed to Teflon powder having an average particle diameter of 11 μm (MP1 manufactured by DU PONT).
000) was used, and a sublimation type thermal transfer transfer medium and an image receptor were prepared and recorded in the same manner as in Example 1. The Teflon powder formed particles in the heat resistant layer, and the height of the part of the particles protruding from the surface of the heat resistant layer was 10 μm. The recording result in this case was that the fusion of the heat from the thermal head did not occur and the transfer medium traveled smoothly, but the obtained image had sticking unevenness in the high density portion and in the low density portion. Missing dots occurred.

Comparative Example 2 A heat-resistant layer coating solution having the following composition was further applied onto the heat-resistant layer of Example 1 using a wire bar, dried with hot air, and further aged in an atmosphere of 60 ° C. for 24 hours. I went. The dry film thickness of only the laminated heat-resistant layers was 2 μm. <Coating liquid for heat-resistant layer for lamination> Polyvinyl butyral (BX-1 manufactured by Sekisui Chemical Co., Ltd.) 10 parts Diisocyanate (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) 5 parts Toluene 100 parts Methyl ethyl ketone 100 parts Teflon powder forms particles in the heat-resistant layer in this example. The height of the formed portion of the particles protruding from the surface of the heat resistant layer was 0.05 μm. In addition, the transfer medium and the image receptor were prepared and recorded in the same manner as in Example 1 except for the above. In this case, heat transfer by the thermal head occurred, the transfer medium could not run smoothly, and the transfer medium was damaged during recording.

Example 2 In Example 1, Teflon powder was used as a lubricant, and zinc stearate phosphoric acid ester powder (LBT-produced by Sakai Chemical Industry Co., Ltd.) was used.
The heat resistant layer was formed in the same manner as in Example 1 except that the heat resistant layer was replaced with 1830). The lubricant formed aggregates in the heat-resistant layer, and the height of the portion of the aggregate protruding from the surface of the heat-resistant layer was 2.5 μm. A transfer medium and an image receptor were prepared and recorded in the same manner as in Example 1 except that the heat resistant layer was formed as described above. According to the recording result in this example, fusion due to heat from the thermal head did not occur, and the transfer medium ran smoothly. An image without missing dots was obtained in the low density area. However, some sticking unevenness occurred in the high density area of the image.

Comparative Example 3 A heat resistant layer was formed in the same manner as in Example 1 except that the lubricant in the coating solution for the heat resistant layer of Example 1 was replaced by melamine resin crosslinked powder (Eposter S manufactured by Nippon Shokubai Kagaku Kogyo KK). The lubricant formed an aggregate in the heat-resistant layer, and the height of the portion of the aggregate protruding from the surface of the heat-resistant layer was 5 μm. A transfer medium and an image receptor were prepared and recorded in the same manner as in Example 1 except that the heat resistant layer was formed in this manner. In this case as well, fusion due to heat from the thermal head did not occur and the transfer medium ran smoothly, but in the obtained image, sticking unevenness occurred in the high density portion and dot omission occurred in the low density portion. It was

Comparative Example 4 A heat-resistant layer coating liquid for lamination having the following composition was further applied onto the heat-resistant layer of Example 2 using a wire bar, dried with hot air, and further aged at 60 ° C. for 24 hours. It was The dry film thickness of only the laminated heat-resistant layers was 5 μm. <Heat layer coating solution for lamination> Polyvinyl butyral (BX-1 manufactured by Sekisui Chemical Co., Ltd.) 25 parts Diisocyanate (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) 12 parts Toluene 100 parts Methyl ethyl ketone 100 parts In this case, the lubricant is an aggregate in the heat resistant layer. And the protrusion height of the aggregate from the heat-resistant layer was 0.05 μm.
A transfer medium and an image receptor were prepared and recorded in the same manner as in Example 1 except that the heat resistant layer was formed in this manner. As a result, heat transfer from the thermal head occurred, the transfer medium did not run smoothly, and the transfer medium was damaged during printing.

Example 3 <Heat-resistant layer coating liquid> Zinc stearate phosphate ester powder (LBT-1830 manufactured by Sakai Chemical Industry Co., Ltd.) 3 parts Curable phosphazene compound (N-2000 manufactured by Idemitsu Petrochemical Co., Ltd.) 10 parts 1-hydroxy Cyclohexyl phenyl ketone 0.3 part Methyl isobutyl ketone 100 parts The heat-resistant layer coating solution having the above composition was dispersed and prepared by a ball mill, coated on a 6 μm-thick aramid film with a wire bar, dried with hot air, and further integrated light amount. 1500
Ultraviolet rays were radiated so as to obtain mj / cm ² . The dry film thickness is 1 μm, and the lubricant forms aggregates in the heat-resistant layer.
The height of protrusion of the aggregate from the heat-resistant layer was 1 μm. A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 1 except that the heat resistant layer was formed as described above. As a result, the fusion due to the heat from the thermal head did not occur, and the transfer medium ran smoothly. In addition, a good image was obtained without sticking unevenness in the high density portion and missing dots in the low density portion.

Example 4 A heat resistant layer was formed in the same manner as in Example 3 except that the lubricant of the heat resistant layer of Example 3 was changed to zinc stearate (SZ-2000 manufactured by Sakai Chemical Industry Co., Ltd.). The lubricant forms aggregates in the heat-resistant layer, and the protrusion height of the aggregates from the heat-resistant layer is 1.5μ.
It was m. A transfer medium and an image receptor were prepared and recorded in the same manner as in Example 1 except that the heat resistant layer was formed as described above. As a result, the fusion due to the heat from the thermal head did not occur, and the transfer medium ran smoothly. In addition, a good image was obtained without sticking unevenness in the high density portion and missing dots in the low density portion.

Example 5 <Sublimable thermal transfer layer coating liquid (A liquid)> Polyvinyl butyral (BX-1 manufactured by Sekisui Chemical Co., Ltd.) 7 parts Diisocyanate (Coronate L manufactured by Nippon Polyurethane Co.) 3 parts Polyethylene oxide (R-400) 3 Part Heat transfer dye (MS Cyan VP manufactured by Mitsui Toatsu Dye Co., Ltd.) 30 parts Ethyl alcohol 170 parts Butyl alcohol 20 parts <Sublimable thermal transfer layer coating liquid (liquid B)> Polyvinyl butyral (Sekisui Chemical BX-1) 10 Part Diisocyanate (Coronate L manufactured by Nippon Polyurethane Company) 3 parts Heat transfer dye (MS Cyan VP manufactured by Mitsui Toatsu Dyes Co., Ltd.) 20 parts Toluene 57 parts Methyl ethyl ketone 57 parts Dioxane 76 parts <Sublimable thermal transfer layer coating liquid (C liquid)> Styrene-maleic acid copolymer (BASF Corporation Suprapearl AP30) 5 parts below Liquid G 12 parts Heat transfer dye (MS Cyan VP manufactured by Mitsui Toatsu Dyes Co., Ltd.) 5 parts Tetrahydrofuran 20 parts <G liquid synthesis> Dimethylmethoxysilane 15 parts Methyltrimethoxysilane 9 parts Toluene 12 parts Mixture consisting of methylethylketone 12 parts The solution was stirred, and 13 parts of 3% sulfuric acid was added thereto to prepare a solution G. Solution A, solution B, and C prepared as described above
The solution was applied to the surface of the sample having the same base sheet and heat-resistant layer as in Example 1 on the opposite side of the heat-resistant layer from solution A to solution B sequentially.
A coating layer of liquid C was formed. Each of these coating layers was coated using a wire bar, and after coating, dried with hot air. Then 60
Aging treatment was performed at 24 ° C. for 24 hours to form a sublimable thermal transfer layer, and a transfer medium was produced. <Image Receiving Body> A synthetic paper having a thickness of 150 μm (Yupo FPG-150 manufactured by Oji Yuka Synthetic Paper Co., Ltd.) was used as a base sheet, and an image receiving layer coating solution having the following composition was applied onto the base sheet using a wire bar. After that, it is dried with hot air and further at 60 ° C for 2
An aging treatment was performed for 4 hours to form an image receiving layer. The film thickness of the image receiving layer was 5 μm. <Image-receiving layer coating liquid> Vinyl chloride-vinyl acetate-vinyl alcohol copolymer (VAGH manufactured by Union Carbide) 10 parts Diisocyanate (Coronate L manufactured by Nippon Polyurethane Co.) 5 parts Epoxy-modified silicone oil (SF8411 manufactured by Dow Corning Toray Silicone Co., Ltd.) ) 2 parts Toluene 20 parts Methyl ethyl ketone 60 parts Using the transfer medium and image receptor prepared as described above, thermal head resolution: 12 dots / mm, image receptor transport speed: 8.4 mm / sec, transfer medium transport speed:
Printing was performed under a thermal printer condition of 0.8 mm / sec. As a result, the fusion due to the heat from the thermal head did not occur, and the transfer medium ran smoothly. Although some sticking unevenness occurred in the high density area of the image, good images without missing dots were obtained in the low density area.

Comparative Example 5 A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 5 except that the heat-resistant layer of the transfer medium had the structure of Comparative Example 1. As a result, the transfer medium ran smoothly without fusing due to heat from the thermal head, but some sticking unevenness occurred in the high-density area of the image, and dot omissions magnified 15 times occurred remarkably. Image quality was degraded.

Comparative Example 6 A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 5 except that the heat-resistant layer of the transfer medium had the structure of Comparative Example 2. As a result, heat transfer from the thermal head occurred, the transfer medium did not run smoothly, and the transfer medium was damaged during printing.

Example 6 A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 5 except that the heat-resistant layer of the transfer medium had the structure of Example 4. As a result, a fusion image due to heat from the thermal head did not occur, the transfer medium ran smoothly, and neither sticking unevenness in the high density portion of the image nor missing dots in the low density portion occurred, and a good image was obtained. .

Comparative Example 7 A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 5 except that the heat-resistant layer of the transfer medium had the structure of Comparative Example 3. As a result, the transfer medium ran smoothly without fusing due to heat from the thermal head, but some sticking unevenness occurred in the high-density area of the image, and dot omissions magnified 15 times occurred, resulting in remarkable image quality. Caused a decline.

Comparative Example 8 A transfer medium and an image receptor were prepared and recorded in exactly the same manner as in Example 5 except that the heat-resistant layer of the transfer medium had the structure of Comparative Example 4. As a result, heat transfer from the thermal head occurred, the transfer medium did not run smoothly, and the transfer medium was damaged during printing.

The composition of each heat-resistant layer of the transfer medium of the above Examples and Comparative Examples, the height of the portion of the particles or aggregates contained in the heat-resistant layer protruding from the surface of the heat-resistant layer, the height and the thickness of the base sheet. Table 1 to 3 and the recording evaluation results of the transfer medium.
Shown in. <Evaluation characteristics and method of displaying results> ・ Fusion due to heat from the thermal head ◯: No fusing ×: Fusing occurred ・ Dot missing in low density area ◯: No dot missing ×: Dot missing occurred ・ High density area in image Sticking in ○: No sticking ×: Sticking occurred

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

As is clear from Tables 1 to 3, the height of the portion of the particles or aggregates contained in the heat-resistant layer protruding from the surface of the heat-resistant layer is 1 to 2.5 μm, and the thickness of the base sheet is 6 μm. In the transfer medium of the example formed with a height in the range of / 6 to 1.2.4, sticking unevenness was slightly observed in some of the transfer media, but in both cases, fusion due to heat from the thermal head and low No missing dots in the density area. On the other hand, the height of the part protruding from the surface of the heat-resistant layer is 0.05μ
m, a sheet formed to a height of 1 / 120th of the thickness of the base sheet, fusion occurred, the transfer medium became defective in running, and damaged (see Comparative Examples 3, 4, 6, and 8). . The height of the portion protruding from the surface of the heat-resistant layer is 5 μm or 10 μm.
m, and if it is formed as high as 1 / 1.2 or 1 / 0.6 of the thickness of the base sheet, the occurrence of fusion can be avoided, but in both cases, dot dropout in the low density area and high density area in the image Sticking unevenness occurs. Such recording results are obtained with substantially the same tendency not only in the normal mode recording but also in the speed difference mode recording (Examples 5 to 6 and Comparative examples 5 to 5).
8). Further, when a curable phosphazene compound is used as the resin binder of the heat-resistant layer, more excellent effect can be obtained (see Examples 3, 4, and 6).

[0035]

As described above, according to the present invention, fusion due to heat from the thermal head is prevented, the transfer medium runs smoothly, the transfer medium is damaged during printing, and the high density portion of the image is generated. It is possible to obtain a sublimation type thermal transfer medium in which sticking unevenness does not occur and dot dropout does not occur in a low density portion. Further, even when the transfer speed of the transfer medium is recorded at 1 / n (n> 1) of the transfer speed of the image receptor, that is, the speed difference mode method can also obtain the above-described effects.

[Brief description of drawings]

FIG. 1 is a sectional view of a sublimation type thermal transfer medium according to the present invention.

[Explanation of symbols]

 1 ... Substrate sheet, 2 ... Sublimable heat transfer layer, 3 ... Heat resistant layer.

Claims (3)

[Claims] 1. A sublimation heat transfer layer containing a sublimable dye and a resin binder is provided on one surface of a base sheet, and a heat-resistant layer containing a lubricant and a resin binder is provided on the other surface of the base sheet. In the sublimation type thermal transfer medium, the heat-resistant layer is formed of a lubricant composed of particles or aggregates, and the particles or aggregates protrude from the surface of the heat-resistant layer, and the height of the protruding portion is 1 mm of the thickness of the base sheet. / 50 or more 1/2
The following is a sublimation type thermal transfer medium. 2. The sublimation type thermal transfer medium according to claim 1, wherein the resin binder of the heat resistant layer is a curable phosphazene compound. 3. The sublimation type thermal transfer medium according to claim 1, wherein the transfer speed of the transfer medium is 1 / n of the transfer speed of the image receptor.
A sublimation-type thermal transfer recording method for recording with (n> 1).