JPH0326818B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-developable color diffusion transfer photographic element, and more particularly to a heat-developable color diffusion transfer photographic element in which an image formed on a heat-developable photosensitive layer is sublimated transferred to a dye-receiving layer to obtain a sharp color image. . Color photography using conventionally known photosensitive silver halide is superior to other color photography in terms of photosensitivity, gradation, image quality, etc., and has been most widely put into practical use. however,
In this method, wet processing is used for steps such as development, bleaching, fixing, and washing, which is time-consuming and labor-intensive, and there are concerns that processing chemicals may cause pollution to the human body, or There are many problems, such as contamination of people by treatment chemicals and the trouble and cost of waste liquid treatment. Therefore, there has been a demand for the development of a method for forming color images that allows dry processing. In recent years, with the development of computers, word processors, and various medical diagnostic devices, the use of color CRTs has progressed, and the demand for high-quality color hard copies is rapidly increasing. Among them, thermal transfer printers are the mainstream and have even been commercialized. However, there is a strong desire to further shorten the printing time, and there is a desire to develop a method for increasing thermal transfer efficiency. For example, methods for obtaining color hard copies of higher image quality by dry processing using silver halide are disclosed in Japanese Patent Application Laid-open Nos. 57-179840, 57-186744, and 57-1989.
It has been proposed in No. 198458 and Japanese Patent Application No. 122596/1984. However, even in the techniques disclosed above, the thermal transfer efficiency of the imagewise released thermal transferable dye to the image-receiving layer is not necessarily sufficient, and it is still desired to develop a method for increasing the thermal transfer efficiency. An effective means of improving such thermal transfer efficiency and increasing dye transferability is to use a material with high transfer efficiency in the dye image receiving layer. There is no description that suggests anything about an image-receiving layer with high transfer efficiency. Further, in the above-mentioned Japanese Patent Application Laid-Open No. 57-198458, the support of the photosensitive layer for color heat development also serves as an image receiving layer, and after color heat development, the photosensitive layer is peeled off and removed by physical means, and the support is removed by physical means. A method for viewing a dye image transferred to is described. In this case, an organic polymer material is used as the dye-receiving support, and the diffusible dye described in this publication diffuses and moves in the binder of the photosensitive layer, and finally dyes the support. It should be clearly distinguished from sublimation transfer, in which a sublimable dye moves through a binder by sublimation, to an image-receiving layer different from the support of the photosensitive layer. SUMMARY OF THE INVENTION It is therefore a first object of the present invention to provide a heat-developable color diffusion transfer photographic element having a dye-receiving layer with improved transfer efficiency, and a second object of the present invention is to provide a heat-developable color diffusion transfer photographic element having a dye receiving layer with improved transfer efficiency; An object of the present invention is to provide a heat-developable color diffusion transfer photographic element from which an image is obtained. (Structure of the Invention) The above-mentioned objects of the present inventors include a binder, an organic silver salt, a developer that develops the silver salt to produce a developed oxidized product, and a sublimation by oxidative coupling or diazo coupling with the developed oxidized product. at least one heat-developable photosensitive layer containing a thermally non-diffusible dye-providing substance capable of releasing a sublimable dye or a sublimable dye precursor; It has been discovered that this can be accomplished with a heat-developable color diffusion transfer photographic element having a dye-receiving layer comprising a saturated polyester layer undergoing transfer. That is, the heat-developable color diffusion transfer photographic element of the present invention uses a dye-receiving layer having a saturated polyester layer with particularly excellent transfer efficiency, and also contains sublimation in the heat-developable photosensitive layer in a stacked relationship with the dye-receiving layer. It is characterized by containing a heat non-diffusible dye-providing substance capable of releasing a sublimable dye or a sublimable dye precursor. The "sublimability" of the sublimable dye or sublimable dye precursor in the present invention generally refers to the property of changing from a solid to a gas without passing through a liquid state. It also includes substances that change from to gas,
Many dyes exhibiting this sublimation property are known in the art. For example, "Dye Handbook"
(Maruzen) is also listed. That is, sublimable dyes are immobile solids at low temperatures and non-diffusible in the absence of a solvent. When it is heated and exceeds a certain temperature, it sublimates and becomes a gas, exhibiting diffusivity and being able to move through space. For example, a sublimable dye coated on a support vaporizes when heated, leaves the support, and diffuses. If there is an image-receiving layer nearby, even if it is not in close contact with the support, it may be adsorbed on or inside the image-receiving layer.
deposits to form a dye image. Sublimable dyes also have the ability to diffuse between layers in a gaseous state. That is, even if there is an intermediate layer between the layer in which the sublimable dye is released and the image-receiving layer, the dye can be diffused and transferred without requiring a solvent. Therefore, by utilizing this property, it is easy to design a multilayer color heat-developable photosensitive material. In addition to sublimation and transfer of a sublimable dye, in the present invention, a dye precursor may be sublimated and transferred to finally form a dye image. The above-mentioned dye precursor referred to in the present invention is one that ultimately contributes to image formation as a dye in the image-receiving layer, and at the time it is bound to the dye-providing substance, at the time it is released from the dye-providing substance,
At the time when the released dye precursor is being diffused or just after reaching the image-receiving layer, it is colorless, and regardless of whether the molecular extinction coefficient is large or small, or the maximum absorption wavelength may be different, but only when a reaction such as oxidation, reduction, decomposition, coupling, protonation, deprotonation, or ionization occurs, does the reaction occur on part or all of the dye precursor, and the dye means something that changes. The sublimable dye or sublimable dye precursor effectively used in the present invention is
It shows sublimation property as mentioned above at 250℃,
Preferably, it satisfies the following sublimation test. (Sublimation test) 100μ thick with 2g/ ^m2 gelatin subbing layer
A layer of 1.46 g/m ² of water-soluble polyvinyl butyral (degree of polymerization 650, average molecular weight 33000, degree of butyralization 9 mol%, degree of acetylation 12 mol%) was provided on a transparent polyethylene terephthalate film of
8.0×10 ^-4 mol/m ² of sublimable dye or sublimable dye precursor is contained in this layer by dispersing alumina bolumina, and filter paper (JISP3801, 6
A polyethylene terephthalate film with a thickness of 100 μm was attached to the film through one sheet, and in the drying test of the hot pressing test (JISL0850), B
After 40 seconds at a test temperature of 180° ± 5°C, the sublimable dye or sublimable dye precursor remaining in the water-soluble polyvinyl butyral layer is
It must have a sublimation property of 7.2×10 ^-4 mol/m ² or less. Furthermore, to describe the conditions of the sublimation test in detail, the hot pressing test described above is based on (JIS
According to the drying test of No. B (180° ± 5°C), place the above element on an ironing board with the polyethylene phthalate film with gelatin sublining facing up and keep it at room temperature. After heating for 40 seconds with an iron, the element is immediately peeled off, and the sublimable dye or sublimable dye precursor remaining in the water-soluble polyvinyl butyral layer is quantified and determined to be 7.2 × 10 ^-4 mol/m ² or less,
That is, it must have sublimation properties such that the sublimation rate (amount contained - amount remaining / amount contained) is 10% or more. In addition, it must have the above-mentioned water solubility. As the water-soluble polyvinyl butyral, ESLETSUKU W-201 (trade name, manufactured by Sekisui Chemical Co., Ltd.) can be used, and as the filter paper, square quantitative filter paper No. 6 (manufactured by Toyo Roshi Kaisha) can be used. The sublimable dye or sublimable dye precursor used in the present invention that can meet the above sublimation test does not contain, for example, a sulfo group or a carboxy group in its molecule, but a nitro group, a cyano group, or a hydroxyl group. , mercapto group, amino group,
It is preferable that it does not contain an amide group, a sulfonamide group, a carbonyl group, an ether group, a thioether group, or a metal atom, or preferably does not contain it. The present invention utilizes a sublimable dye or a sublimable dye precursor that can meet the sublimation test as described above in combination with a dye-receiving layer containing a saturated polyester layer to provide an effective high concentration to the image-receiving layer for the first time. A transferred image could be obtained, which is an unexpected effect of the present invention. Therefore, according to the present invention, compared to the conventional so-called instant photography method in which a dye is diffused in a concentrated alkaline solution that is harmful to the human body to form an image, the color thermal diffusion transfer method according to the present invention can be performed at a constant temperature. It is safe and excellent because a transferred image can be obtained by simply heating it for a period of time. In the present invention, the dye-providing substance capable of releasing the above-mentioned sublimable dye or sublimable dye precursor is thermally non-diffusible and substantially does not cause intralayer or interlayer diffusion even when heated. Furthermore, the dye-providing substance in the present invention is capable of releasing a sublimable dye or a sublimable dye precursor as a function of development, and acts directly on the redox reaction during development, or indirectly through a cross-oxidizing agent, etc. This causes a release reaction. Reactions in which a dye donor releases a sublimable dye or a sublimable dye precursor include decomposition, elimination, and ligand exchange reactions, but in the present invention, a diazo coupling method using an active site substitution coupler is used. Alternatively, an oxidation coupling method is effective. For example, a dye formed by diazo coupling or oxidative coupling between an oxidized aromatic primary amine color developing agent and a coupler having a pallast group via a bond at its active site has sublimation properties. For example, in diazo coupling or oxidative coupling between an oxidized product of an aromatic primary amine color developing agent and a coupler having a sublimable dye or a sublimable dye precursor as a leaving group via a bond to the active site, the sublimable dye precursor is the reaction in which is released. The method of the present invention is the latter, and is based on the following general formula (1)
The dye-donating substances shown are effective. General formula (1) A-B-C (wherein, A represents a coupler residue; B represents a simple bond or a divalent bonding group; C represents a sublimable dye residue or a sublimable dye precursor residue; (represents a group) Particularly preferred dye-providing substances in the present invention are:
A in the general formula (1) is represented by the following general formula (2) or (3). General formula (2) General formula (3) In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and
R ₈ is a hydrogen atom, a halogen atom (preferably a chlorine atom, a bromine atom, an iodine atom), an alkyl group (preferably an alkyl group having 1 to 24 carbon atoms), such as a methyl group, an ethyl group, or a t-butyl group. group, s-octyl group, pentadecyl group, cyclohexyl group, trifluoromethyl group, benzyl group, phenethyl group, etc.), aryl group (e.g. phenyl group, naphthyl group, tolyl group, mesityl group, etc.),
Acyl groups (e.g. acetyl group, tetradecanoyl group, piparoyl group, benzoyl group, etc.), alkyloxycarbonyl groups (e.g. methoxycarbonyl group, benzyloxycarbonyl group, etc.), aryloxycarbonyl groups (e.g. phenoxycarbonyl group, P -Tolyloxycarbonyl group, α-
naphthothoxycarbonyl group, etc.), alkylsulfonyl group (e.g., methylsulfonyl group, etc.), arylsulfonyl group (e.g., phenylsulfonyl group, etc.), carbamoyl group (e.g., methylcarbamoyl group, butylcarbamoyl group, tetradecylcarbamoyl group, N-methyl -N-dodecylcarbamoyl group, phenylcarbamoyl group, etc.), acylamino group (e.g. n-butylamide group, β-
phenoxyacetamide group, β-methanesulfonamide acetamide group, β-methoxyacetamide group, etc.), alkoxy group (preferably an alkoxy group having 1 to 18 carbon atoms, such as methoxy group, ethoxy group, octadecyloxy group, etc.) ),
It represents a sulfamoyl group (eg, methylsulfamoyl group, phenylsulfamoyl group, etc.), a sulfoamino group (eg, methylsulfamino, tolylsulfamino), or a hydroxy group. However, preferably at least one of R ₁ , R ₂ , R ₃ and R ₄ and at least one of R ₅ , R ₆ , R ₇ and R ₈ are ballast groups that reduce thermal diffusivity, for example, A group containing a hydrophilic group such as a sulfo group, a carboxy group, or a hydroxy group, or a group containing an alkyl group and having 8 or more carbon atoms. In addition, at least one set of R ₁ and R ₂ and R ₃ and R ₄ , and at least one set of R ₅ and R ₆ , and R ₆ and R ₇ are bonded to each other, and saturated or unsaturated 5- to 6
It may form a membered ring. In the general formula (1), B represents a simple bond, ie, a case in which a coupler residue and a sublimable dye residue or a sublimable dye precursor residue are directly bonded, or a divalent bonding group. Examples of divalent bonding groups include: and so on. In the general formula (1), the sublimable dye residue represented by C is preferably a monoazo dye residue, an anthraquinone dye residue, a nitrodiphenylamine dye residue, or the like. The sublimation temperature of these sublimable dyes is 70℃~300℃
℃, preferably 80℃ to 250℃. There are various methods for measuring sublimation temperature, and the measured value may differ depending on the method. In the present invention, methods for evaluating the fastness of dyes can be used, and among them, the values measured by the drying test of the hot pressing test (JIS L0850) have shown a good correlation with the transfer characteristics. Specific examples of dye-providing substances that are particularly effective in the present invention are shown below, but the present invention is not limited thereto. (Exemplary dye-donating substance) The above heat non-diffusible dye-providing substance according to the present invention is used by being contained in the heat-developable photosensitive layer,
As the binder for the development photosensitive layer, either hydrophilic or hydrophobic polymers can be used.
These may be used alone or in combination. Among the above binders, hydrophilic binders include transparent or translucent hydrophilic colloids, such as proteins such as gelatin, gelatin derivatives, cellulose derivatives, starch, or natural substances such as polysaccharides such as gum arabic, and polyvinylpyrrolidone. , synthetic polymers such as water-soluble polyvinyl compounds such as acrylamide polymers, and the like. For example, a transparent synthetic polymer as a hydrophilic binder used in the present invention is disclosed in US Pat.
No. 3142586, No. 3193386, No. 3062674, No. 3220844, No. 3287289, No. 3411911,
etc. are described. Effective polymers include
Water-insoluble polymers containing monomers such as alkyl acrylate, alkyl methacrylate, acrylic acid, sulfoalkyl acrylate or sulfoalkyl methacrylate, and Canadian Patent No. 774054
Examples include those having circulating sulfobetaine units as described in No. Preferred polymers include polyvinyl butyral, polyacrylamide, cellulose acetate butyrate, cellulose acetate propionate, polymethyl methacrylate, polyvinyl pyrrolidone, polystyrene, ethyl cellulose, polyvinyl chloride, chlorinated rubber, polyisobutylene, butadiene styrene copolymer, vinyl chloride. Examples include vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, polyvinyl alcohol, polyvinyl acetate, benzyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate phthalate, and the like. Among these polymers, especially polyvinyl butyral, polyvinyl acetate ethyl cellulose,
Preferred are polymethyl methacrylate, cellulose acetate butyrate, and the like. If necessary, two or more types may be used in combination. The amount of the hydrophobic polymer binder is 1/10 to 10 times, preferably 1/4 to 4 times, the weight of the organic silver salt oxidizing agent described below. In the present invention, it is most advantageous to use a heat-developable photosensitive material using an organic silver salt for the photosensitive function and developability function. This is because in terms of photosensitivity, it is possible to improve sensitivity or spectral sensitization by using silver halide brought into catalytic contact with an organic silver salt. Furthermore, it is possible and, in fact, effective to improve the image quality by adding halation or anti-irradiation dyes in the method of the present invention in which a color image is separated from a silver image by sublimation transfer. In terms of developability, it has the advantage that it is easy to relate the dissolution physical development reaction of the organic silver salt that occurs by heating to the release reaction of the sublimable dye or sublimable dye precursor of the dye-providing substance. ing. That is, in the method of the present invention, the dissolution physical development reaction of an organic silver salt, the reaction in which a sublimable dye or a sublimable dye precursor is released using the reaction, and the conditions for sublimation and transfer thereof are appropriately set. In particular, it is possible to obtain clear color transfer images by only one heating (thermal development). Heat-developable photosensitive materials form images only by heat development.
Due to the specificity of not applying a fixing process, a well-known drawback is image deterioration due to printout. Therefore, conventional photothermographic materials have the trouble of having to be stored in a cool, dark place after image formation.
In the method of the present invention, even if the photosensitive layer is exposed and printout occurs, the resulting release reaction of the sublimable dye or sublimable dye precursor,
Furthermore, their influence on sublimation and transfer becomes extremely small. If a method of peeling the photosensitive layer and the image-receiving layer is used, almost no problems will occur. The photosensitive layer of the heat-developable photographic element used in the present invention basically contains (1) a binder, (2) an organic silver salt, (3) a photosensitive silver halide, (4) a developer, and (5) A thermally non-diffusible dye-providing substance is contained, but these are not necessarily contained only in the photosensitive layer, but may also be contained, for example, in a layer adjacent thereto. As the organic silver salt used in the present invention,
Organic acid silver salts such as gallotsucate silver salt, oxalate silver salt, especially fatty acid silver salts such as behenate silver salt, stearate silver salt, palmitate silver salt, imidazole silver salt, benzotriazole silver salt, Nitrogen acid silver salts such as 4-sulfobenzotriazole silver salt, 5-nitrobenzotriazole silver salt, and 4-hydroxybenzotriazole silver salt, as well as thione silver salt, saccharin silver salt, 5-chlorsalicylaldoxime silver salt, etc. be. Examples of the photosensitive silver halide used in the present invention include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide, and the like. The above-mentioned photosensitive silver halide can be prepared by any method known in the photographic field, such as a single-jet method or a double-jet method. Silver halide gelatin emulsions prepared according to the procedure give favorable results. The photosensitive silver halide described above may also be chemically sensitized by any method known in the photographic field. Examples of such sensitization methods include gold sensitization, sulfur sensitization, gold-sulfur sensitization, and reduction sensitization. This photosensitive silver halide may have coarse or fine grains, but the preferred grain size is about 1.5 microns to about 0.001 microns,
More preferably about 0.5 micron to about 0.05 micron. Furthermore, as another method for preparing photosensitive silver halide,
It is also possible to cause a photosensitive silver salt-forming component to coexist with an organic silver salt to form a photosensitive silver halide in a portion of the organic silver salt. The photosensitive silver salt forming component is a halogen releasing agent, and this method is well known in the field of heat-developable photosensitive materials. Furthermore, the developer used in the present invention includes a developer capable of oxidative coupling or diazo coupling with the dye-providing substance, such as paraphenylene diamines, sulfoamide anilines,
Sulfamic acids can be used alone or in combination. These developers may also be used as precursors, such as the following thermally decomposable precursors. Additives include acetylating agents, activators, stabilizers,
These include color toning agents, sensitizers, thermal antifoggants, printout inhibitors, spectral sensitizers, filter dyes, and the like.
These are described in detail in Research Disclosure No. 17029 (1978), and can be utilized in carrying out the method according to the present invention. According to the present invention, the dye sublimated and diffused from the heat-developable photosensitive layer by heat development is dyed into the dye image-receiving layer which is laminated with the photosensitive layer. The dye image-receiving layer according to the present invention includes a saturated polyester layer, and the saturated polyester includes a polymer compound obtained by polycondensation of a polybasic acid and a polyhydric alcohol. For example, a typical example is polyethylene terephthalate (PET, melting point 260°C), which is obtained by polycondensation of terephthalic acid and ethylene glycol. In addition, polybutylene terephthalate (PBT, melting point 224℃), poly 1,4-cyclohexane dimethyl terephthalate (PCHT, melting point 290℃)
℃), polyethylene isophthalate (melting point 107℃)
etc. However, since the photographic elements of this invention are heated to between 80° and 200°C during development, the melting point of the saturated polyester used in the image-receiving layer must be above the development temperature, and therefore at least 100°C.
It needs to be at least 120°C, preferably 120°C.
℃ or higher. The above-mentioned saturated polyester is to be distinguished from unsaturated polyester, which contains a double bond in its molecular structure that can be crosslinked with a vinyl compound to form a three-dimensional network structure. The dye image-receiving layer according to the present invention contains a saturated polyester having the above-mentioned melting point, but may also contain other organic polymeric substances, in which case the content of the other organic polymeric substances must be 60% by weight or less. is essential for achieving the purpose of the present invention. Generally, phthalic acid polyesters do not dissolve in many solvents, but recently granular soluble polyesters and water-dispersible saturated polyester binders have been developed. In the present invention, as the binder for layer coating, the above-mentioned saturated polyester may be used in the form of a solution in a solvent, but it is preferable to use a water-dispersed type because it is easy to handle. Further, as the image-receiving layer of the present invention, a saturated polyester film itself with a thickness of 20 to 200 μm may be used, but it is also possible to use a saturated polyester film itself having a thickness of 20 to 200 μm. Mix an aqueous dispersion of the substance, or an aqueous solution or a solvent solution, and if necessary, add a paint mixed with common pigments such as calcium carbonate, titanium dioxide, clay, etc., and apply 0.5 to 30 g/m to the support. A layer formed by coating approximately ² layers can be used as an image-receiving layer. Examples of other organic polymer substances used in the present invention include polyvinylpyrrolidone, polycarbonate, polyamide, cellulose acetate, polystyrene, polyvinylcarbazole, polyvinyl alcohol, polyvinyl butyrol, polymethyl methacrylate, polyethylene methacrylate, polyvinyl chloride, etc. Examples include, but are not limited to. Among these organic polymeric substances, polyvinylpyrrolidone is most preferred, and a dye image-receiving layer suitable for the purpose of the present invention can be obtained. In addition, as the support used for the image-receiving layer in the present invention, as mentioned above, a wide range of materials can be used as long as it can withstand the temperature during heat development processing, such as glass, paper, metal, and their analogues. In addition to polyimide films, acetyl cellulose films, cellulose ester films, polyvinyl acetal films, polystyrene films, polycarbonate films, polyethylene terephthalate films, and films or resin materials related thereto. Typical examples of preparing a dye image-receiving layer by using a support as the dye-receiving layer and coating the saturated polyester layer according to the present invention thereon will be described below. Preparation Example 1 A 10% aqueous dispersion of saturated polyester (Pyronal MD-1200 manufactured by Toyobo Co., Ltd.) was applied onto baryta paper using a wire bar so that the dry film thickness was approximately 3μ (approx. 3g/m ² in coating amount). The mixture was dried to prepare a dye-receiving paper. Preparation Example 2 Aqueous dispersion of saturated polyester used in Preparation Example 1
Slurry of heavy calcium carbonate (Maruo Calcium Super 1500) in 100ml of 10% liquid (solid content 70%)
Mix 25ml and proceed in the same manner as in Preparation Example 1 until the dry film thickness is approx.
A dye-receiving paper with a 9μ image-receiving layer was prepared. Preparation Example 3 Saturated polyester pellets (Toyobo Pylon)
200) was dissolved in 150 ml of methyl ethyl ketone and coated on a glass surface using a wire bar to prepare an image-receiving layer having a dry film thickness of approximately 5 μm (coating amount: 5 g/m ² ). Preparation Example 4 Saturated polyester aqueous dispersion used in Preparation Example 1 10
% solution 100ml and polyvinylpyrrolidone 10% aqueous solution 50ml
10 g of titanium dioxide was added to the mixed solution, and the mixture was thoroughly stirred, and then coated on baryta paper to a dry film thickness of about 3 μm (coating amount: about 3 g/m ² ), and dried to prepare a dye image-receiving paper. In the present invention, imagewise exposure to photographic elements can include sunlight, tungsten lamps, fluorescent lamps,
Mercury lamp, halogen lamp, xenon lamp,
Laser light, light emitting diode, CRT, or
This is performed using OFT (optical fiber tube), etc. In the present invention, development is carried out by heat development, and any method applicable to ordinary heat-developable photosensitive materials can be used for this heat development. For example, the photosensitive material may be brought into contact with a heated plate, a heated roller or drum, passed through a high-temperature atmosphere, high-frequency heating may be used, or a conductive layer may be provided in the photosensitive material to conduct electricity. It is also possible to utilize Joule heat generated by a strong magnetic field.
There are no particular restrictions on the heating pattern in thermal development, including methods of preheating and then reheating, and methods of heating at high temperatures for short periods of time.
Alternatively, it is possible to continuously raise, lower, or repeat heating at a low temperature for a long time, or even to heat discontinuously, but a simple pattern is preferable. Usually, the developing temperature is 80℃~200℃, and the developing time is 1 second~10
A range of minutes is preferred. For heat development, a commercially available heat development machine can also be used. For example, “Image forming 4634 type”
(Sony Tektronix), "Developer Module 277" (3M), and "Video Hard Copy Unit NWZ-301" (Japan Radio). The imagewise distribution of the sublimable dye or sublimable dye precursor formed from the dye-providing substance by heat development is such that at least a portion of it is sublimated into the image-receiving layer by the heat during heat development or by reheating. , transcribed. The stacking relationship between the photothermographic material and the image-receiving layer means that they both share a support and form the same coating composition, or that they each have separate supports and dyes are mixed together. The layer containing the dye-donating substance and the image-receiving layer are in close contact with each other, and the layer containing the dye-donating substance and the image-receiving layer are separated from each other by an intermediate layer or a certain gap. This indicates that they are in a substantially parallel state. If the photothermographic material and the image-receiving layer are in a stacked relationship, it is possible to form a clear color image by sublimation transfer. In the present invention, the image-receiving layer contains, for example, titanium white, silica, acid clay, heavy or light calcium carbonate, talc, kaolin, natural Alternatively, general pigments such as synthetic silicates, aluminum hydroxide, zinc oxide, etc. can be included as appropriate. Further, the image-receiving layer may be integrated with the photosensitive layer, or may be in a form that can be separated from the photosensitive layer. Examples of the present invention are shown below. <Preparation of 4-hydroxybenzotriazole silver salt> Dissolve 34.0 g of silver nitrate in 450 c.c. of water, add aqueous ammonia dropwise while stirring, and stop dropping when the formed silver oxide is completely dissolved. did. The above ammoniacal silver nitrate solution was added to a solution of 27.5 g of 4-hydroxybenzotriazole (synthesized according to the method described in Japanese Patent Application No. 1065/1982) in 350 c.c. of ethanol and stirring. The reaction solution was filtered, washed with water and methanol, and dried to obtain 46.4 g of white crystals. Example 1 To 7.26 g of 4-hydroxybenzotriazole silver, 24 c.c. of a water-soluble polyvinyl butyral 25% aqueous solution (Sekisui Chemical Co., Ltd., Eslec W-201), 116 c.c. of water, and 70 c.c. of methanol were added, and an alumina ball mill was added. The mixture was pulverized and dispersed to obtain a silver salt dispersion. To 25 c.c. of this silver salt dispersion, add 0.21 g of phthalic acid, 0.16 g of phthalazine, and 0.93 g of the exemplary dye-providing substance CPM-2.
g, 0.42 g of the following developer, 5 c.c. of a 25% aqueous solution of water-soluble polyvinyl butyral, 10 c.c. of water, and 36 mg of silver iodide emulsion with an average particle size of 0.04 μm converted to silver.
on photographic baryta paper to a wet film thickness of 55μ.
It was applied with a wire bar so that (Developer) The dried sample was exposed to 30,000 CMS through a step wedge. On the other hand, a photographic element of the present invention was prepared using a polyethylene terephthalate film with a thickness of 50 μm as the dye image-receiving layer, and this was designated as Sample 1. For comparison, a photographic element was prepared using a polyimide film as the image-receiving layer. This was designated as sample 2. Wash paper was sandwiched between the coated surface of the exposed sample and the image receiving layer made of the synthetic resin film, and the sample was pressed and heated for 30 seconds using an iron with a surface temperature of 150°C, and then the sample and the resin film were pulled together. I peeled it off. The transferred image on the film surface obtained by heat development was measured, and the results are shown in Table 1 below.

[Table] As is clear from Table 1, Sample 1 having the image-receiving layer according to the present invention can obtain a dye image with superior transfer density compared to the comparative sample. Example 2 4.5 g of silver behenate, 20 c.c. of toluene, 20 c.c. of acetone
cc and 3.2 g of polyvinyl butyral were added, and Dispersion-1 was prepared using an ultrasonic homogenizer. Behenic acid dispersion 2 was obtained by heating and dissolving 3.4 g of behenic acid in 40 c.c. of an 8% by weight polyvinyl butyral acetone solution and stirring under ice cooling. On the other hand, 0.20 g of phthalic acid, 0.13 g of phthalazine, 2.55 g of the following developer, and 0.92 g of CPM-3 were dissolved in 40 c.c. of an 8% by weight polyvinyl butyral acetone solution to obtain Solution-1. (Developer) Further, silver trifluoroacetate and lithium bromide were reacted in a 10% by weight polyvinyl butyral acetone solution to obtain Emulsion-1. Mix 10c.c. of dispersion-1 and 10c.c. of dispersion-2,
Then, 0.3 cc of a 0.05% by weight methanol solution of the following sensitizing dye and 20 mg of mercuric acetate were added. (sensitizing dye) Finally, Solution 1 was added and coated onto a transparent polyester film using a wire bar to a wet film thickness of 74 μm to form a photosensitive layer. On top of that, a white reflective layer and an image-receiving layer having the following composition:
A was provided, and another transparent polyimide film was adhered on top of the image-receiving layer-A to prepare sample 3 for comparison. <White reflective layer> (Unit: g/m ² ) Titanium dioxide (average particle size: 1.5μ) 15 Cellulose diacetate 1.2 Sodium dodecyl sulfate 0.08 Ethanol 25 Water 30 <Image-receiving layer-A> (Unit: g/m ² ) Cellulose diacetate 1.6 Ethanol 21 Water 42 On the other hand, a photosensitive layer, a white reflective layer, and an image-receiving layer were prepared in exactly the same manner as Sample 3 except that an image-receiving layer-B having the following composition was provided as an image-receiving layer, and a polyimide film was adhered to form the present invention. Sample 4 was prepared. <Image receiving layer B> (Unit: g/m ² ) 40% saturated polyester aqueous dispersion (Pional MD-1200 manufactured by Toyobo) 4.0 Water 63 The photosensitive layer side of these samples was exposed to 30,000 CMS through a step wedge. An iron with a surface temperature of 100°C was pressed onto the photosensitive layer side for 30 seconds. A negative silver image and a positive image of the unreacted dye-providing substance were formed in the photosensitive layer, and a yellow reflective negative image as shown in Table 2 below was obtained in the image-receiving layer.

[Table] As shown in Table 2, sample 4 of the present invention having an image-receiving layer according to the present invention can obtain a transferred image with a higher maximum reflection density by thermal development than the comparative sample. Example 3 4-hydroxybenzotriazole silver 8.71 g CPM-3 13.3 g Ossein gelatin 10% by weight aqueous solution 84 c.c. Water 120 c.c. Methanol 96 c.c. The above composition was dispersed in an alumina ball mill,
Dispersion-3 was obtained. Solution-2 having the following composition was similarly prepared. Ossein gelatin 10% by weight aqueous solution 42c.c. 4-aryl-3-amino-5-mercapto-
1,2,4-triazole 28 mg Methanol 10.5 cc Emulgen 950 (KAO-ATLAS) 245 mg Dimethylurea 3.5 g After mixing 25 c.c. of the above dispersion-3 and 15 c.c. of solution-2, the average particle size A 0.04 μm silver bromide emulsion was added in an amount of 0.11 g in terms of silver, and coated on photographic baryta paper to obtain a first photosensitive layer. Next, 8.71 g of 4-hydroxybenzotriazole silver in Dispersion-3 was replaced with 7.80 g of 5-nitrobenzotriazole, and 13.3 g of CPM-3 was replaced with 12.8 g of CPM-8, and Dispersion-4 was prepared in the same manner.
I got it. Take 25 c.c. of the dispersion liquid-4, add thereto 3.2 cc of a 0.02 wt% methanol solution of the following sensitizing dye, then add 15 c.c. of solution-2, and apply on top of the first photosensitive layer. This was used as a second photosensitive layer. (sensitizing dye) The obtained sample was exposed to white light of 100,000 CMS through a step wedge, and the sample (A) was
Sample (B) was obtained by using Kodatsu Kurafuten Filter No. 74 in addition to the conditions of sample (A), and sample (B) was obtained by using Kodatsu Kuratuten Filter No. 94 in addition to the conditions of sample (A). C). Meanwhile, 1.2 g/m 2 of saturated polyester (used in Example 2), 0.6 g/m ² of polyvinylpyrrolidone, and 1.2 g/m ² of titanium dioxide were applied to photographic baryta paper according to the preparation method of Preparation Example 4 above. g/m ² and dried to prepare image-receiving paper. The photosensitive layer side of each sample and the coated surface of the image receiving paper were placed together and heated for 30 seconds using an iron with a surface temperature of 160°C. The maximum and minimum reflection densities of the image-receiving paper of each sample obtained by tearing it off are determined according to the measurement light in the third section below.
Shown in the table.

Table 3 shows that in the heat-developable color diffusion transfer photographic elements of the present invention, not only monochrome images but also multi-color images can be obtained by heat development. In addition, even if the heating time was shortened to 20 seconds, it was almost 3rd.
Results close to the table were obtained and it was found that further reductions in processing time were possible with the heat-developable color diffusion transfer photographic elements of the present invention.

Claims (1)

[Claims] 1. A binder, an organic silver salt, a developer that develops the silver salt to produce an oxidized developer, and a thermal nondiffusion capable of releasing a sublimable dye or a sublimable dye precursor through oxidative coupling or diazo coupling with the oxidized developer. at least one heat-developable photosensitive layer containing a sublimable dye-providing substance; and a dye-receiving layer comprising a saturated polyester layer in stacked relation with the heat-developable photosensitive layer and to which the sublimable dye or sublimable dye precursor is transferred. A heat-developable color diffusion transfer photographic element characterized in that it has.