JPH054232B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a dye transfer member used for recording by thermal transfer, and particularly to a dye transfer member used for high-speed recording using an electronic device such as a thermal head or a laser beam. Conventional Structure and Problems Conventionally, full-color thermal transfer materials containing sublimable dyes that can be applied to high-speed recording have been widely used. However, the images recorded by these methods suffer from disturbances in image quality, especially in the intermediate tone area, and the main causes of this are drop-outs in the recording in areas where energy is applied and dye sublimation or scattering (dropouts) in areas where energy is not applied. It is known that this is caused by noise (noise). OBJECTS OF THE INVENTION An object of the present invention is to provide a dye transfer member that reduces dropouts and noise, particularly in the halftone region, and provides recorded images with good image quality. Structure of the Invention The dye transfer material of the present invention has a substrate, a sublimable dye, non-sublimable particles, and a binder that binds them together, and some of the non-sublimable particles are connected to the binder or the substrate of the sublimable dye. Any point in the range that protrudes from a parallel surface (reference plane) and is surrounded by a circle with a radius of 200 μm from each point on the outer periphery of the cross section of any non-sublimable particle on this reference plane is another non-sublimable particle. Characterized by being occupied. To explain this with reference to Figures 1 and 2, 1 is a base, 2 is a layer consisting of a sublimable dye and a binder,
3 represents a non-sublimable particle, the particle 3 protrudes from the reference plane l of the layer 2, and the radius r=
The structure is such that any point in the range 2a surrounded by a 200 μm circle is occupied by other non-sublimable particles. Among these, especially when other non-sublimable particles are present somewhere in the area surrounded by the circle of r=20 μm, this has an extremely large effect. In the present invention, the non-sublimable particles do not necessarily need to be exposed beyond the sublimable dye-binder layer (the layer consisting of the sublimable dye and binder is hereinafter abbreviated as this), and the non-sublimable particles do not necessarily need to be exposed outside the sublimable dye-binder layer (hereinafter referred to as a layer consisting of a sublimable dye and binder), and are The non-sublimable particles 3 may be covered with a sublimable dye-binder layer 2', as shown in FIG. In this case, the reference plane l becomes as shown in the figure. Even in this case, the effect of the non-sublimable particles described later is not impaired at all. Further, non-sublimable particles as shown in FIG. 4 are distinguished by broken lines in the figure and are regarded as two particles. The same applies to those having three or more protrusions. Furthermore, as shown in FIG.
Good results are obtained when the height h of the sublimable dye-binder layer 2 from the reference plane l is within the range of 0.1 to 30 μm. Further, the particle size of the particles 3 is preferably in the range of 0.1 to 10 μm. Next, the action of the non-sublimable particles 3 will be explained using the recording example shown in FIG. 5 using the thermal head 5. 1 Non-contact action Since the sublimable dye-binder layer 2 and the clay paper 5 do not come into direct contact, the dye does not transfer due to pressure or melting, and the dye transfers only by sublimation or vaporization, resulting in a good transparent image. give. 2. Heat conduction effect The heat applied from the thermal head 4 through the substrate 1 is smoothly conducted to the dye near the non-sublimable particles themselves, helping to sublimate the dye uniformly. Also,
The binder has the following functions. That is,
Since a sufficient amount of sublimable dye is retained and the distance between the reference surface 1 and the clay paper 5 is made close, sufficient recording density can be given to the image. Further, the dye transfer member can be made to withstand repeated use. The effect of non-sublimable particles is not limited only when they are present on the substrate, but also when they partially penetrate into the substrate. In addition, if there are no other non-sublimable particles within the outside shaded area in Figure 2, or if
is smaller than 0.1 μm, the effect of non-sublimable particles is not sufficient. The material constituting the non-sublimable particles is selected from metals, metal oxides, metal sulfides, graphite, carbon black, silicon carbide, minerals, inorganic salts, organic pigments, or polymeric compositions. Examples of highly effective methods are listed below. Metal: aluminum, silicon, germanium,
tin, copper, zinc, silver, iron, cobalt, nickel,
Chromium and alloys based on chromium. Metal oxides: alumina, beryllium oxide, magnesium oxide, copper zinc oxide, zinc oxide, indium oxide, tin oxide, titanium oxide, silicon oxide, iron oxide, cobalt oxide, nickel oxide, manganese oxide, tantalum oxide, vanadium oxide, oxide Tungsten, molybdenum oxide, and their compounds doped with impurities. Metal sulfides: copper sulfide, zinc sulfide, tin sulfide, molybdenum sulfide. Minerals: Magnesium minerals, lime minerals, strontium minerals, barium minerals, zirconium minerals, titanium minerals, tin minerals, phosphorus minerals, aluminum minerals (waxite, kaolin, clay), silicon minerals (quartz, mica, talc, zeolite, diatom) soil). Inorganic salts: carbonates or sulfates of alkaline earth metal elements (maglucium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate). Polymer compositions: phenolic resin, melamine resin, urethane resin, epoxy resin, silicone resin, urea resin, diallyl phthalate resin, alkyd resin, acetal resin, acrylic resin, methacrylic resin, polyester resin, cellulose resin, starch and its derivatives , polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene,
Fluorine resin, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polyamide, polyvinyl alcohol, polycarbonate,
Polysulfone, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyether ether ketone, polyamino bismaleimide, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, polyamideimide, polyacrylonitrile, AS resin , ABS resin, SBR, and compositions based on these. All of these materials have high mechanical strength and are not destroyed by the pressure of bringing the dye transfer member and receiver into intimate contact, for example, and are suitable for achieving the objectives of the present invention. In addition to the above-mentioned polymer compositions, those having a melting point or softening point of 100° C. or higher are particularly effective. This is because many of the sublimable dyes used have sufficient sublimation ability even below 100°C, and polymer compositions that meet this condition will not be transferred to the image receptor, so high-quality transparent images can be obtained using dyes alone. This is so that you can be saved. Furthermore, the thermal conductivity of non-sublimable particles is 10 ^-3 cal/
When the temperature is cm·s·k or more, the heat conducted from the substrate to the non-sublimable particles is smoothly conducted to the dye near the non-sublimable particles, which helps the dye to sublimate uniformly and improves the image quality. In addition, the thermal conductivity of the base is 10 ^-3 cal/
A similar effect is given when the distance is cm・s・k or more. Description of Examples Example 1 5 parts by volume of sublimable dye represented by the structural formula of Formula 1, 5 parts by volume of polycarbonate, dichloromethane
100 parts by volume and alumina particles with an average particle size of 3 μm were mixed in different amounts and stirred separately in a ball mill.
The dispersion was applied to a 12 μm thick capacitor paper using a wire bar to obtain a dye transfer material. Using these, images were drawn on activated clay paper using a thermal head. The recording conditions were as follows. Linear density of main scanning and sub-scanning: 4 dots/mm Recording power: 0.7 W/dot Head heating time: 4 msec Table 1 shows the number of dropouts and noise generated per 1000 dots, and the number of dropouts and noise that exist on the dye transfer material. The maximum length max (dpi) of the minimum distance dpi between the projected figures between the alumina particle pi and particles existing in its vicinity is shown. Figure 6 shows the arrangement of particles and
Shows the relationship with dpi. The dpi was determined from scanning electron micrographs taken perpendicularly to capacitor paper. In addition, h defined in Figure 1 was determined from scanning electron micrographs of the cross section of the dye transfer material, and was found to be 7 μm in all cases with different amounts of alumina particles.
It was below. In addition, as a comparative example, the results when no alumina is mixed are also shown.

[Table] Example 2 Average particle diameters are 0.1, 0.5, 1, 2, 3, respectively.
Alumina particles of 5, 10, 15, 20, 50 and 100μm
20 parts by volume, 5 parts by volume of the sublimable dye of Example 1, 5 parts by volume of polyester resin (trade name: Vylon 200), and 100 parts by volume of chloroform were stirred separately in a ball mill for each alumina particle. A dye transfer material was prepared by coating the same substrate as No. 1 in the same manner. Recording was performed in the same manner as in Example 1 using these, and the second
The table shows the number of dropouts and noise generated per 1000 dots, max (dpi), and h.

[Table] From the above examples, it can be seen that the recorded images obtained using the dye transfer material of the present invention have good image quality with far less dropout and noise than the comparative examples. In particular, max (dpi) 20μm, 1μm
Particularly excellent results were obtained in the case of h15 μm.
This is clear from the low noise and dropout in Table 2. In addition, dye transfer materials having other non-sublimable particles or binders according to the present invention other than these examples also have a max (dpi) of 200 μm,
Excellent effects were obtained when the conditions of 0.1 μm and 30 μm were met. Effects of the Invention As described above, the dye transfer member of the present invention provides recorded images with good image quality with reduced dropouts and noise. Furthermore, full-color images can be obtained using three types of dye transfer bodies that develop cyan, magenta, and yellow colors.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a dye transfer body according to the present invention;
Figure 2 is a diagram showing the cross section of non-sublimable particles at the reference plane of the sublimable dye-binder layer and the range where other non-sublimable particles exist, and Figures 3 and 4 are other configurations of the dye transfer body. A vertical cross-sectional view showing an example, Figure 5 is a cross-sectional view of the recording state in a thermal head, and Figure 6 is a cross-sectional view of the recording state in a thermal head.
It is a diagram of the definition of dpi. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Sublimable dye-binder layer, 3...Non-sublimable particles, l...Reference surface, h...
Projection height of non-sublimable particles.

Claims (1)

[Scope of Claims] 1. Comprising a substrate, a sublimable dye, non-sublimable particles, and a binder that binds them together, with a portion of the non-sublimable particles protruding from a surface of the binder or sublimable dye that is substantially parallel to the substrate. , and the radius from each point on the circumference of the cross section of any non-sublimable particle at this surface
A dye transfer material characterized in that any point within the range surrounded by a 200 μm circle is occupied by other non-sublimable particles. 2 The height of any non-sublimable particle from the surface is
The dye transfer member according to claim 1, which has a particle size within the range of 0.1 to 30 μm. 3 The thermal conductivity of non-sublimable particles is 10 ^-3 cal/cm・
3. The dye transfer material according to claim 1 or 2, wherein the dye transfer material has a particle size of s·k or more. 4. The dye transfer material according to claim 1 or 2, wherein the substrate has a thermal conductivity of 10 ^-3 cal/cm·s·k or more.