JPH0441678B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a transfer body for heat-sensitive recording used for transfer recording by applying heat, and particularly to a transfer body effective for high thermal energy recording using a sublimable dye as a coloring material. Structure of conventional examples and their problems Full-color transfer bodies containing sublimable dyes have been widely studied. However, images recorded using these transfer bodies have problems with disturbances in halftone areas due to dropouts in areas where energy is applied and dye sublimation or scattering (noise) in areas where energy is not applied. There is. To prevent this, particles of 0.1 to 1000 μm are added, but this has the disadvantage of causing a decrease in concentration. OBJECTS OF THE INVENTION An object of the present invention is to provide a transfer member that does not cause dropouts or noise and provides good image quality and high recording density. Structure of the Invention In the thermal recording transfer body of the present invention, the coloring material layer provided on the surface of the substrate is made of sublimable dye and ultrafine particles prepared by a vapor phase method with an average particle diameter of 0.1 μm as the upper limit. and a binder that binds them together. Here, the coloring material layer contains ultrafine particles created by a vapor phase method in which the average particle diameter of a single grain is 0.1 μm as the upper limit, and as a result, the surface of the coloring material layer is ultrafine and has a rough surface. and uniform thermal conductivity. As a result, inhomogeneous transfer due to melting of the sublimable dye and contact with the image receptor is drastically reduced, and the heat applied to the transfer body is uniformly conducted to the sublimable dye through the ultrafine particles, resulting in a homogeneous transfer of the sublimable dye. Sublimation is promoted and a decrease in recording density can be prevented. Synthetic amorphous silica, alumina, titanium oxide, and silicic acid compounds are most likely to be used as ultrafine particles produced by a gas phase method with an average particle diameter of 0.1 μm as the upper limit. In particular, ultrafine particles produced by a vapor phase method are more uniform in particle size than pulverized particles, and therefore are effective when added to a coloring material layer because they are uniformly dispersed. DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of the configuration of a transfer body of the present invention. 1st
In the figure, 1 is a base and 2 is a coloring material layer, which is composed of a sublimable dye 3, ultrafine particles 4, and a binder 5. The ultrafine particles were produced by a gas phase method. Examples of materials produced by the gas phase method include high-purity ultrafine particulate silica, aluminum oxide, and titanium oxide sold by Nippon Aerosil Co., Ltd. under the name Aerosil. The weight ratio of ultrafine particles to binder is 10 ^-1
It can be used in the range of ~ ¹⁰² . This is because if the weight ratio is less than 10 ^-1 , it is impossible to uniformly roughen the surface, and if it is more than 10 ² , the particle size of the coating liquid increases and uniform roughening cannot be achieved. In particular, the effect is great when the ratio to the binder is in the range of 1 to 30.
Ultrafine particles are well dispersed by ultrasound, a ball mill, a homogenizer, etc. Next, a specific example will be explained. 2 parts by weight of various fine particles, 2 parts by weight of a sublimable dye represented by the following structural formula, 4 parts by weight of polysulfone, and 100 parts by weight of methylene chloride were stirred separately in a ball mill, and these were placed on a 12 μm thick condenser paper. The dispersion was coated with a wire bar to obtain a transfer body. Average particle size as fine particles produced by vapor phase method
Alumina of 0.02 μm, titanium oxide with an average particle size of 0.03 μm produced by the same vapor phase method, and alumina and titanium oxide with an average particle diameter of 5 μm produced by crushing the same were used. Using these transfer bodies, images were drawn on activated clay paper using a thermal head. The recording conditions were as follows. Main scanning and sub-scanning linear density: 4 dots/mm Recording power: 0.7 W/dot Head heating time: 2 to 8 msec The following table shows the number of dropouts and noise generated per 1000 dots when the head heating time is 4 msec. give. As a comparative example, the results are shown in which a liquid containing no fine particles was applied.

[Table] A transfer material with added fine particles has significantly reduced dropout and noise compared to a transfer material that does not contain fine particles. FIG. 2 shows the relationship between pulse width and recording density. Curve a is for alumina added using a vapor phase method, and curve c is for an average particle size of 5μ made by crushing.
The results show the results of applying a liquid containing m of alumina. The transfer material made by the vapor phase method and added with alumina and titanium oxide does not cause a decrease in concentration. Effects of the Invention As described above, the thermal recording transfer body of the present invention has the following features:
To provide a good recorded image with reduced dropout and noise without causing a decrease in density. Also,
Full-color images can also be obtained using three types of transfer bodies that provide recorded images in cyan, magenta, and yellow.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a transfer body for thermal recording according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between recording density and pulse width of the transfer body for thermal recording according to the embodiment. 1...Substrate, 2...Coloring material layer, 3...Dye, 4...
...Fine particles, 5...Binder.

Claims (1)

[Scope of Claims] 1 Sublimable dye on the surface of the substrate, the average diameter of the single particles is
A transfer material for heat-sensitive recording having a coloring material layer containing ultrafine particles and a binder produced by a vapor phase method with an upper limit of 0.1 μm, the surface of the coloring material layer being roughened by the ultrafine particles. . 2 The weight ratio of ultrafine particles to sublimable dye is
10 ^-1 - ^2. The heat-sensitive recording transfer body according to claim 1, wherein 3. The heat-sensitive recording transfer material according to claim 1, wherein the ultrafine particles are alumina or titanium oxide produced by a vapor phase method.