Abstract: Thermal dye transfer printing systems which are adapted For multiple-use printing modes wherein one dye transfer sheet is repeatedly used and which comprise a dye transfer sheet having, on a substrate, a dye transfer layer containing a sublimable dye and a binder resin and a dye receiving sheet having a dye receiving layer which has a diffusion rate of the dye smaller than the dye transfer layer. This is effective in suppressing a lowering of printing density owing to the increase in number of printing cycles using one dye transfer sheet. Alternatively, the dye transfer sheet is constituted such that the dye transfer layer is made of a plurality of sub-layers in which the concentration of the dye decreases from the sub-layer formed directly on the substrate toward the surface side of the dye transfer layer. The dye is invariably supplied from the higher concentration sub-layers to ensure full color printing with a remarkably increasing number of multiple-use printing cycles.

Abstract: A method of resistive sheet transfer recording is disclosed, in which the thermal diffusion coefficient of a resistive sheet (1) in the range of 1 to 100.times.10.sup.-6 m.sup.2 /s is combined with that of an electrode head (2) in the range of 0.1 to 50.times.10.sup.6 m.sup.2 /s, thereby making it possible to form a high-quality image at high sensitivity and high speed.

Abstract: It can be obtained a receiving sheet for a dye transfer type thermal printing which is improved in a curing speed, image reliability, recording sensitivity, and dot reproducibility, and useful for high speed and/or relative-speeds printing by arranging a polymer layer on a substrate and then a cured resin layer of a moisture-curable resin on the polymer layer.

Abstract: Thermal dye transfer printing systems which are adapted for multiple-use printing modes wherein one dye transfer sheet is repeatedly used and which comprise a dye transfer sheet having, on a substrate, a dye transfer layer containing a sublimable dye and a binder resin and a dye receiving sheet having a dye receiving layer which has a diffusion rate of the dye smaller than the dye transfer layer. This is effective in suppressing a lowering of printing density owing to the increase in number of printing cycles using one dye transfer sheet. Alternatively, the dye transfer sheet is constituted such that the dye transfer layer is made of a plurality of sub-layers in which the concentration of the dye decreases from the sub-layer formed directly on the substrate toward the surface side of the dye transfer layer. The dye is invariably supplied from the higher concentration sub-layers to ensure full color printing with a remarkably increasing number of multiple-use printing cycles.

Abstract: A dye transfer sheet consisting of a transfer substrate and a coloring material layer comprising a high concentration layer which comprises a dye and is formed on the transfer substrate and a low concentration layer which comprises a water soluble resin or water dispersible resin having a polydimethylsiloxane structure and has a lower dye concentration than the high concentration layer and is formed on the high concentration layer. A dye transfer sheet consisting of a transfer substrate and a coloring material layer comprising a high concentration layer which comprises a dye and a binder polymer cross-linked with a cross-linking agent and is formed on the transfer substrate and a low concentration layer which comprises a water soluble resin or water dispersible resin and has a lower dye concentration than the high concentration layer and is formed on the high concentration layer.

Abstract: The dye transfer type thermal printing sheet of the present invention comprises(a) a substrate, and(b) a lamina comprisinga dye andeither a cured product of a moisture curing type resin or a reaction-cured product of a moisture curing type resin and a reactive silicone oil,on at least one side of the substrate.According to the present invention, a surface release property and surface lubricity can easily be imparted to the color material layer or to the surface layer. Further, since no crosslinking agent is required to cure the resin, curing at low temperature becomes possible. The dye transfer type thermal printing sheet of the present invention can provide a printing sheet useful for high speed recording and/or relative speed recording.

Abstract: When a dyeable layer comprises cured product of at least one moisture-curable type resin, it can have a high image reliability, permit easy control of the printing sensitivity and serve for both low-speed printing and high-speed printing. A receiving sheet having a dyeable layer excellent in surface slipperiness which is useful for high-speed printing and/or relative-speeds printing, can be obtained when the dyeable layer comprises cured product of a moisture-curable type resin, or reaction cured product of a moisture-curable type resin with a reactive silicone oil.

Abstract: A thermal transfer printing system comprising a dye transfer sheet having a dye carrier layer containing at least one sublimable dye and a dye acceptor sheet having a dye-receiving layer with good affinity for the sublimable dye. The two sheets are arranged during printing operations in such a way that they are facing through a slippage means which is in the form of a layer of particles of lubricating or thermally releasable materials. This system is adapted for a printing process in which a relative speed of the dye transfer sheet to a thermal printing head is smaller than a relative speed of the dye acceptor sheet under which the dye transfer sheet is heated in an imagewise pattern to permit the sublimable dye to deposit on the dye-receiving layer according to the imagewise pattern. The dye transfer sheet and the dye acceptor sheet most suitable for use in the system are also described.

Abstract: A dye-receiving sheet comprising a substrate and a dye-receiving layer formed on one side of the substrate, the substrate being made of an extruded, biaxially stretched sheet of a mixture of white fine particles and a polyester resin. The extruded, stretched sheet has a specific gravity of from 1.0 to 1.38. A layer of polymer having a thermal deformation temperature or softening point lower than that of the extruded, stretched sheet may be formed on the extruded, stretched sheet. The dye-receiving sheet has high brightness and good flexibility with high printing sensitivity.

Abstract: A thermal transfer printing system comprising a dye transfer sheet having a dye carrier layer containing at least one sublimable dye and a dye acceptor sheet having a dye-receiving layer with good affinity for the sublimable dye. The two sheets are arranged during printing operations in such a way that they are facing through a slippage means which is in the form of a layer or particles of lubricating or thermally releasable materials. This system is adapted for a printing process in which a relative speed of the dye transfer sheet to a thermal printing head is smaller than a relative speed of the dye acceptor sheet under which the dye transfer sheet is heated in an imagewise pattern to permit the sublimable dye to deposit on the dye-receiving layer according to the imagewise pattern. The dye transfer sheet and the dye acceptor sheet most suitable for use in the system are also described.

Abstract: A dye-receiving sheet comprising a substrate and a dye-receiving layer formed on one side of the substrate, the substrate being made of an extruded sheet of a mixture of white fine particles and a polyester resin and a layer of a polymer material or composition whose thermal deformation temperature or softening point is lower than that of the extruded sheet. This sheet has high printing sensitivity.

Abstract: This invention provides a magnetic fluid having a rich hue and containing an organic compound as dispersion medium.The magnetic fluid of this invention is constructed by mixing, into a magnetic dispersion, a colorant prepared by beforehand treating a coloring material with a solubilizing treating agent or a dispersibilizing treating agent. Said solubilizing treating agent or dispersibilizing treating agent has a hydrophobic group and a functional group absorbable or linkable to said coloring material. As said coloring material, a dyestuff, an organic pigment or an inorganic pigment is used. A colorant prepared by subjecting an intermediate of said coloring material to said treatment is also usable. Further, a colorant prepared by pretreating a coloring material so as to give the coloring material an absorbability or a linkability to said solubilizing treating agent or dispersibilizing treating agent and then subjecting the beforehand pretreated coloring material to said treatment is also usable.

Abstract: Dye-receiving sheets for heat transfer recording comprising on a substrate, a dye-receiving layer consisting essentially of a cured product of an acrylate having two acrylic or methacrylic unsaturated bonds. The sheet is used in combination with a dye transfer sheet comprising a sublimable dye, and has a high affinity for the dye and a high heat resistance without bleeding of the dye.

Abstract: In an image forming method including the steps of electrostatically adhering light-transmissive particles onto the surface of a photoconductive substrate, exposing an image on the particles, and developing the image by separating the particles through which no light is transmitted from the particles through which light is transmitted in order to obtain a particle image consisting of one of the particle groups, the step of equalizing the potentials of the particles through which light is transmitted and those of the particles through which no light is transmitted is inserted between the exposure step and the development step. This additional step eliminates the defect in the conventional method in which degradation of color purity occurs at a thick color portion.

Abstract: This invention provides a magnetic fluid which is diversified in hue and stable in the electric fields.The magnetic fluid of this invention is composed of a dispersion of ferromagnetic particles dispersed by a surfactant, and a colorant having the same charge as the dispersing medium in said dispersing medium.The dyes effective for use in this invention are the nonionic azo dyes, anthrquinone dyes and metal-containing dyes, and the pigments useful in this invention are the organic or inorganic pigments treated so as to have an isoelectric point in the dispersing medium. A magnetic fluid having black color or other desired hues can be obtained by properly selecting the dye and/or pigment.The magnetic fluid of this invention exhibits its excellent properties particularly when used as a recording material.

Abstract: The disclosure is directed to light-transmitting image forming particles each containing at least a colorless subliming dye which develops color through reaction with a color developing agent, and also a coloring agent, and moreover, having at least a pair of parallel faces. When applied to a particular image forming process as disclosed, the particles can provide color images with an expanded latitude and a superior color purity, while, by bevelling or planing-off the edges defining the parallel faces, exposure amount may be reduced as compared with particles without such bevelling.

Abstract: An image forming process comprising steps of arranging on a support member, in accordance with image signals, image forming particles containing dye former which develops its color in reaction with a color developing agent, heat-transferring the dye former from the particles to an image receiving substrate. After the heat-transfer step, the color developing agent is caused to adhere to the dye former heat-transferred on the image receiving substrate to provide colored images.Choice of the image receiving substrate and the color developing agent is expanded. Fogging is not caused, color purity is not lowered, and the other image receiving material is not polluted due to reevaporation of the dye former which is on the image receiving substrate and is not reacted with color developing agent.