JPH0441676B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a transfer type thermal recording method for obtaining a record by transferring dye on a transfer member to an image receptor by applying heat. Conventional structure and its problems As shown in FIG. 1, in the conventional transfer type thermal recording method, a transfer member 1 is heated with a thermal head 2 and a sublimable dye is applied to an image receptor 4 having a color developing layer 3 on its surface. Image 5 was obtained by sublimation. However, with this method, there is a problem of disturbance in image quality in the intermediate tone area. The main causes of this are drop-outs in the recording in areas where energy is applied and sublimation or scattering of the sublimable dye (noise) in areas where energy is not applied. Furthermore, when a thermal head is used as a recording means, the transfer body 1 made of an inexpensive and homogeneous film used to obtain a homogeneous image is fused by the high temperature generated by the thermal head and is stabilized on the thermal head. I was unable to drive. On the other hand, as an image receiver that forms an image by selectively heating the sublimable dye on the transfer member 1 according to an image signal, the base material is paper with uneven thickness made of pulp. Since the color developing layer formed in the image forming layer is made of inorganic fine particles and a dye-dyeable binder, not only the halftone image quality is not smooth and an image with high recording density cannot be obtained, but also the image quality is poor. The stability, including light resistance, was poor. OBJECTS OF THE INVENTION The present invention aims to provide a transfer-type thermal recording method that reduces dropouts and noise, especially in the intermediate tone area, and provides a good image and recording density by stably running a thermal head. purpose. Structure of the Invention In order to achieve the above object, the transfer type heat-sensitive recording method of the present invention provides a lubricious heat-resistant layer made of fine particles, a liquid lubricating substance, and a polymeric substance on one side of a substrate, and a lubricating heat-resistant layer on the other side. A transfer body provided with a coloring material layer consisting of a sublimable dye, non-sublimable particles in which some of the particles protrude from the surface of the coloring material layer, and a binder, and inorganic fine particles and a dye-dyeable binder. and an image receptor having a color developing layer on its surface made of a binder that is incompatible with the binder are arranged so that the colorant layer and the color developing layer face each other, and the transfer body An image is formed on the image receptor by selectively heating from the side of the slippery heat-resistant layer. Effects According to the above structure, the heat resistance of the lubricating heat-resistant layer in contact with the thermal recording means such as the thermal head of the transfer body is improved by the heat-resistant resin, the surface is roughened by the fine particles, and the liquid lubricity is improved. Since a small amount of the substance flows out from inside the slippery heat-resistant layer at high temperatures, stable running properties of the transfer body can be imparted. Further, due to the presence of non-sublimable particles in the coloring material layer that serve as a spacer, the transfer member and the image receiver are not subjected to an unnecessary pressing force. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view for explaining the transfer type thermal recording method of this embodiment. In the figure, 6 is a transfer body in this embodiment, and 7 is an image receptor. While moving these relatively, they are heated by a thermal head 2 to sublimate the sublimable dye, thereby obtaining a recorded image 5. The difference from the conventional example shown in FIG. 1 lies in the transfer body 6 and the image receptor 7, which will be explained next. FIG. 3 is an enlarged sectional view of the transfer body 6. In the figure, 8 is a polyethylene terephthalate film with a thickness of 9 μm, and 9 is a polyethylene terephthalate film with a coating liquid having the composition shown in Table 1 applied to its lower surface with a wire bar, and after evaporating the solvent with hot air at 60°C, It is a slippery heat-resistant layer that is cured by irradiation with a high-pressure mercury lamp.

[Table] In Table 1, white carbon (Carplex FPS-1) is a fine particle with a particle size of 0.5 μm.
Silicone oil is used as a liquid lubricating substance, and epoxy acrylate resin (viscosity
150 poise) was used. On the other surface of the substrate 8 are a sublimable dye and non-sublimable particles 1 whose particle size partially protrudes from the surface of the coloring material layer 11.
A color material layer 11 made of 0 and a binder is formed. Here, the relationship between the non-sublimable particles 10 and the coloring material layer 11 in the present invention shows good results when the height h of the coloring material layer 11 from the reference plane is within the range of 0.1 to 100 μm, and 1 μm≦ It has an especially excellent effect when h≦10μm. That is, non-sublimable particles 1
Suitable particle sizes for 0 are between 0.1 and 100 μm, especially between 1 and 10 μm. In this example, alumina particles of 1 to 10 μm were used,
The thickness of the color material layer 11 was 2 μm. The coloring material layer 11 is formed by applying a dye solution consisting of 4 parts by volume of each sublimable dye represented by the molecular formula of or, 4 parts by volume of polysulfone as a binder, and 100 parts by volume of monochlorobenzene as a solvent onto the substrate 8 using a wire bar. A transfer body was prepared. Here, the dyes , and are colored cyan, magenta, and yellow, respectively. FIG. 4 is an enlarged sectional view of the image receptor 7 in this embodiment. In the figure, 12 is polypropylene synthetic paper, and has a color developing layer 13 on one side thereof. The color developing layer 13 was prepared by mixing the following three types of emulsion coating solutions A, B and C in appropriate proportions, applying the mixture using a wire bar, and drying by evaporating the solvent with hot air. Coating liquid A: 20% by volume aqueous dispersion of polyester (trade name: Vylonal) B: 20% by volume aqueous dispersion of polyethylene C: 20% by volume aqueous dispersion of silica with an average particle size of 200㎓ Color developer layer 13 is dye-dyeable The binder 14 is made of polyester as a binder, polyethylene which is incompatible with the polyester, and inorganic fine particles 15 of silica having an average particle size of 200㎓. With such a structure, a microscopic void 16 is generated in the color developing layer 13, and the sublimable dye easily reaches the coloring point 17 and develops color. The transfer body 6 in FIG. 3 and the image receptor 7 in FIG. I made him draw it. The recording conditions were as follows. Main scanning and sub-scanning linear density: 4 dots/mm Recording power: 0.7 W/dot Thermal head heating time: 8 m ^sec Table 2 shows the number of image dropouts and noise generated under these conditions, and the transfer material. The maximum length max (dpi) of the minimum distance dpi between projected figures between any alumina particle pi existing in No. 6 and particles existing in its vicinity is shown. FIG. 5 shows the relationship between the arrangement of alumina particles 10 and dpi. The dpi was determined from a scanning electron micrograph taken from a direction perpendicular to the substrate 8. Further, h defined in FIG. 3 was determined from scanning electron micrographs of the cross section of the transfer body, and was 7 μm or less in all cases where the amount of alumina particles was varied. In addition, as a comparative example, the results when no alumina particles were mixed are also shown.

[Table] In addition, the recording densities were 1.3, 1.2, and 0.8 for cyan, magenta, and yellow, respectively. The color reproducibility at this time is shown in FIG. 6 as a chromaticity diagram. Furthermore, these images were subjected to sunlight fastness tests in accordance with JIS and LO841 standards. Table 3 shows coating liquid A,
The volume ratio of B and C, the recording density of each color of cyan, magenta, and yellow, and the grade of sunlight fastness are shown.

[Table] *Comparative example According to the above results, according to this example, a transfer material in which the coloring material layer contains alumina particles (non-sublimable particles) with some particles protruding from the surface of the coloring material layer was obtained. Dropouts and noise are reduced because the image is recorded using a silica (inorganic particle), polyester (dye-dyed material), etc. Images are recorded using an image receptor that has a color developing layer consisting of a dye-stainable binder) and polyethylene (a dye-dyeable binder and an incompatible binder), resulting in improved recording density and fastness. An excellent transfer type thermal recording method can be obtained. Furthermore, with this configuration, the dye penetrates into the dyed layer and a deep, high-density image can be formed, so that the color reproduction range can be expanded as shown in the chromaticity diagram shown in FIG. Note that the scope of the present invention is not limited to the examples, and similar effects were obtained in various embodiments as described below. (1) Fine particles used in the slippery heat-resistant layer include metals, metal oxides, metal sulfides, metal carbides, graphite, carbon black, minerals, inorganic salts,
Organic salts, organic pigments, etc. can be used, but especially synthetic amorphous silica, carbon black, alumina,
Titanium oxide and the like are useful. Synthetic amorphous silica includes anhydrous silica and hydrated silica, and ultrafine particles produced by a gas phase method are useful as anhydrous silica. For example, high-purity ultrafine particulate silica (product name: Aerosil, Nippon Aerosil Co., Ltd.) developed by West German Dexa GmbH, aluminum oxide and titanium oxide (both produced by Nippon Aerosil Co., Ltd.), which were similarly produced by a vapor phase method. etc. Depending on the characteristics of the sublimable dye used, ultrafine silica may react with the sublimable dye. In such cases, the silanol groups present in the silica may be chemically combined with methyl groups, etc. Partially substituted bonded hydrophobic silica can be used. Ultrafine particles are well dispersed by ultrasonic waves, triple rolls, homogenizers, and the like. The main component of white carbon is hydrated silicon dioxide and may also contain calcium silicate. For example, they are commercially available under the names of Shionogi & Co., Ltd. "Carplex", Nippon Silica Industries Co., Ltd. "Nipseal", Mizusawa Chemical Industries Co., Ltd. "Silton", etc. The fine particles can be used in an amount of 0.1 to 20% by weight based on the binder. Particularly stable is the range of 5 to 10 V.0% by weight. (2) Liquid lubricating substances include, for example, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrodienepolysiloxane, fluorosilicone oil, and various other modified silicone oils (epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, denaturation, alcohol denaturation, polyether denaturation, alkyl/aralkyl/polyether denaturation, epoxy/polyether denaturation, etc.),
Silicone-based lubricating substances such as copolymers of organic compounds such as polyoxyalkylene glycol and silicone, various fluorosurfactants such as fluoroalkyl compounds, fluoro-based lubricants such as low polymers of trifluorochloroethylene, etc. synthetic oils, saturated hydrocarbons, animal and vegetable oils, minerals, etc. (3) The polymer material used for the slippery heat-resistant layer is not particularly limited, and may include thermoplastic resin,
Various resins (crosslinked resins) cured by heat, light, electron beam, etc. can be used. In particular, the cured resin has good adhesion to the substrate and good heat resistance. Examples include silicone-based, acrylate-based, epoxy-based, and unsaturated aldehyde-based resins. Among these, cured products of acrylate resins exhibit excellent properties. Furthermore, since the resin cured by light or electron beams is easily cured in a short time, it is easy to produce long transfer bodies and exhibits good characteristics. For example, light or electron beam cured products of oligoacrylates and spiran resins,
Alternatively, photocured epoxy resins using aromatic diazonium salt catalysts are excellent. Various reactive diluents can be added to the resin. The film thickness of the polymer composition is not particularly limited. Generally, from a production standpoint, polymer compositions with a film thickness of 0.1 μm or more are easily obtained and exhibit uniform characteristics. (4) Disperse dyes, basic dyes, and diformers of basic dyes are used as sublimable dyes. (5) As a binder for sublimable dyes and non-sublimable particles, instead of polysulfone, binders with high melting points or softening points such as polycarbonate, polyphenylene oxide, and cellulose derivatives can be used to bind to the image receptor due to heat during recording. This contributes to obtaining high-quality transparent images without causing melt transfer. (6) In place of spherical alumina, non-sublimable particles include metals, metal oxides, metal sulfides, metal carbides, graphite, carbon black, silicon carbide, minerals, inorganic salts, organic pigments, and polymer compositions. Choose from one of them. Examples of highly effective methods are listed below. Metals: aluminum, silicon, germanium, tin, copper, zinc, silver, iron, cobalt, nickel, chromium, and alloys based on these. Metal oxides: alumina, beryllium oxide, magnesium oxide, cuprous oxide, zinc oxide, indium oxide, tin oxide, titanium oxide, silicon oxide, iron oxide, cobalt oxide, nickel oxide, manganese oxide, tantalum oxide, vanadium oxide,
Tungsten oxide, 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 (magnesium carbonate, calcium carbonate,
Strontium carbonate, barium carbonate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate), and metal silicates. Polymer composition: 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, fluororesin, polyethylene, polypropylene, polystyrene, polydivinylbenzene, Polyvinyl acetal, polyamide, polyvinyl alcohol, polycarbonate, polysulfone, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyether ether ketone, polyamino bismuthimide, 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 will not be destroyed by the pressure of bringing the transfer member and receiver into close 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 produced using only sublimable dyes. This is because it can be obtained. (7) As the inorganic fine particles used in the color developing layer of the image receptor, particles of alumina, activated clay, etc. with a particle size of 10 μm or less can be effectively used instead of silica. In particular, inorganic fine particles made of silica, alumina, or titanium oxide with an average particle size of 500 Å or less have an extremely high density of coloring points per unit volume.
This greatly contributes to increasing recording density. Activated clay, silica, etc. having acidity are also effective. (8) Instead of polyester, polyamide, acrylic resin,
Acetate resins are used, and it is effective to use hydrocarbon resins such as polypropylene, polystyrene, polybutadiene, styrene-butadiene rubber (SBR), fluorine resins, or silicone resins instead of polyethylene as binders that are incompatible with these resins. It is. (9) The best image can be obtained when the shape of the non-sublimable particles is spherical, but even if they are polygonal, as shown in FIG. 7, sublimable dye 19 Even if the coloring material layer 11 is covered with , a good image can be obtained if the height h from the reference surface of the coloring material layer 11 is within the range of 0.1 to 100 μm. (10) In contrast to FIG. 7, which shows the configuration of the longitudinal section of non-sublimable particles in the coloring material layer, in FIG. The effect is great when any point in the range 20 of r=200 μm is occupied by other non-sublimable particles. Among these, especially r = 20μm
If other non-sublimable particles exist somewhere in the area surrounded by , it will have a significant effect. (11) The substrate used for the transfer body and image receptor is not limited to polyethylene terephthalate and polypropylene synthetic paper, but polymer films are particularly effective. For example, ester polymers such as polyethylene terephthalate, polyethylene naphthalate, and polycarbonate, amide polymers such as nylon, cellulose derivatives such as acetyl cellulose and cellophane, polyvinylidene fluoride, and tetrafluoroethylene-hexafluoropropylene copolymers. , fluorine-based polymers such as tetrafluoroethylene, ether-based polymers such as polyoxymethylene, polyacetal, polystyrene, polyethylene, polypropylene,
Olefinic polymers such as methylpentene polymers, imide polymers such as polyimide, polyamideimide, polyetherimide, etc. can be used. In particular, polyester-based polymers are thin,
It is useful because it has a certain degree of heat resistance and is inexpensive. In addition, imide-based, amide-based, and other polymers, which have a base material that is more heat resistant than polyester polymers, are useful when the transfer body is used repeatedly or at high speeds because they have excellent heat resistance. (12) In the examples, color images were explained, but very unique effects are also shown when using multiple types of sublimable dyes. That is, in order to obtain a black image using sublimable dyes, usually a plurality of types of sublimable dyes are used.
However, due to non-uniform transfer of the sublimable dye due to direct contact between the transfer member and the receiver, or preferential transfer of the sublimable dye near the receiver, a wide range of recording densities from low to high recording densities can be achieved. It has been extremely difficult to obtain good black images over a long period of time. However, according to the transfer type thermal recording method of the present invention, the transfer to the image receptor is facilitated by uniform sublimation of each sublimable dye, and the preferential transfer of the sublimable dye existing near the image receptor is achieved. Therefore, each sublimable dye is evenly transferred to the image receptor. Therefore, good black images can be obtained over a wide recording density range. If at least one of the multiple types of sublimable dyes is selected from basic dyes (including colored dyes or color formers that develop color with electron acceptors) and at least one type is selected from disperse dyes, image reception is possible. By appropriate selection of the body, blacks with very good color tone and high recording density can be obtained. This is thought to be because the basic dye and the disperse dye have different die sites (dying points) and do not cause harmful interactions with each other in dyeing and color development. In addition, by combining appropriate types of dyes, good images of arbitrary hues can be obtained in a wide range of recording densities. Effects of the Invention As described above, according to the transfer type thermal recording method of the present invention, stable running properties of the transfer member are provided, and good images with less dropouts and noise can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a transfer example for explaining a conventional transfer method, FIG. 2 is a cross-sectional view of a transfer example for explaining a transfer method in an embodiment of the present invention, and FIG.
The figure and FIG. 4 are cross-sectional views of the transfer body and the image receptor;
Figure 5 is a diagram explaining the arrangement of non-sublimable particles, Figure 6 is a diagram explaining the arrangement of non-sublimable particles.
The figure is a chromaticity diagram of a recorded image, FIGS. 7 and 8 are cross-sectional views of the transfer body, and FIG. 9 is a cross-sectional view of non-sublimable particles. 5... Image, 6... Transfer body, 7... Image receptor,
8, 12... Base body, 9... Slippery heat-resistant layer, 10...
Non-sublimable particles, 11...coloring material layer, 13...color developing layer, 14...binder, 15...inorganic fine particles.

Claims (1)

[Claims] 1. A slippery heat-resistant layer made of fine particles, a liquid lubricating substance, and a polymeric substance is provided on one surface of the substrate, and a sublimable dye and some particles of a coloring material layer are provided on the other surface. A transfer body provided with a coloring material layer consisting of non-sublimable particles and a binder protruding from the surface, inorganic fine particles, a dye-dyeable binder, and a binder incompatible with this binder. an image receptor having a color developing layer on its surface, the colorant layer and the color developer layer being arranged in a facing state, and selectively heated from the lubricious heat-resistant layer side of the transfer body. A transfer type thermal recording method for forming an image on the image receptor. 2. The transfer type heat-sensitive recording method according to claim 1, wherein the binder incompatible with the dye-dyeable binder is a hydrocarbon resin, a fluororesin, or a silicone resin. 3. The transfer type thermal recording method according to claim 1, wherein the inorganic fine particles are fine particles having a particle size of 500 Å or less. 4. The transfer type thermal recording method according to claim 1, wherein the inorganic fine particles are acidic fine particles.