JPS6385544A - Image forming method - Google Patents

Abstract

PURPOSE:To eliminate uneven development and to shorten the time for processing by heating water to a specific temp. or above and supplying the same from the outside at the time of heating a photosensitive element in the presence of said water and bade (precursor) to transfer a diffusible dye to a dye fixing layer. CONSTITUTION:The photosensitive element is constituted of a base, photosensitive silver halide, binder and dye donative material, etc. Such photosensitive element is heated in the presence of the water and the base (precursor), after or simultaneously with imagewise exposing, to transfer the formed or released diffusible dye to the dye fixing element. The above-mentioned water is supplied from the outside and is supplied after the temp. thereof is increased to >=30 deg.C. Then, the sharp and high-density image having no unevenness is obtd. in the short time for processing.

Description

[Detailed description of the invention] Background of the invention Technical field The present invention relates to a method of forming an image by heating.

Prior Art and its Problems Many methods have been proposed for obtaining color images by heat development. Regarding a method of forming a color image by combining an oxidized developer and a coupler, U.S. Pat. , No. 761, 270 p.
- Aminophenol-based reducing agent is used in Belgian patent No. 802
, No. 519 and Research Disclosure Magazine 1975
Sep. 31, 32, sulfonamidophenolic reducing agents, and U.S. Pat. No. 4,021,240,
A combination of a sulfonamidophenol reducing agent and a 4-arm coupler has been proposed.

However, in this method, a reduced silver image and a color image are simultaneously generated in the exposed area after thermal development, resulting in a problem that the color image becomes cloudy.

To solve this problem, there are methods to remove the silver image by liquid processing or to transfer only the dye to another layer, such as a sheet containing an image-receiving layer. It has the disadvantage that it is not easy to transfer.

Furthermore, the above-mentioned methods generally require a relatively long time for development, and the resulting images have the drawbacks of high fog and low density.

In order to improve these drawbacks, the present inventors have provided an image forming method using silver halide in which a movable dye is formed in the form of an image and transferred to a dye fixing layer (Japanese Unexamined Patent Application Publication No. 58-1971). -149046, 59-154445,
No. 59-165054, No. 59-180548, U.S. Patent No. 4,503,137, No. 4,474.86
No. 7, No. 4,483,914, No. 4,455,3
63).

Among such image forming methods, in the image forming method in which heating is performed in the presence of water, a base and/or a base precursor, and a trace amount of water, it is common to supply water to a photosensitive material and heat it. .

However, in this case, unless the photosensitive material absorbs water uniformly and quickly, problems such as uneven development and a longer total processing time will occur.

(2) Purpose of the Invention An object of the present invention is to provide an image forming method that easily provides sufficient density in a short processing time without causing unevenness in development.

■Disclosure of invention These objects are achieved by the invention described below.

That is, the present invention involves heating a photosensitive element having at least a photosensitive silver halide, a binder, and a dye-providing substance on a support in the presence of water and a base and/or a base precursor after or simultaneously with imagewise exposure. death,
An image forming method in which a generated or released diffusible dye is transferred to a dye fixing layer, and the image forming method is characterized in that the water is supplied from the outside and the temperature of the water at that time is set to 30° C. or higher.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

In the image forming method of the present invention, a photosensitive element is heated in the presence of water and a base and/or a base precursor after or simultaneously with imagewise exposure.
t~l+ Casting medium I To place Prayer chair 7h ↓
A] In this case, the water is supplied from outside, and the temperature of the water at that time is 30°C or higher, preferably 35°C or higher. In the present invention, there is no particular limit to the temperature of the water, and steam may be applied, but if the temperature is too high, the method of supplying water from the outside will become mechanically complicated.
A temperature of about 60°C, particularly about 40 to 60°C is suitable.

From the viewpoint of shortening the total treatment time, it is desirable that the water application time be as short as possible. The preferred application time is 5 seconds or less, particularly preferably 2 seconds or less. For example, as shown in Table 4 in Examples below, in order to apply the necessary amount of water in 5 seconds or less, it is unstable at 25 °C, and above 30 °C.
2 is preferable.

In the present invention, water may be supplied by any method as long as water is supplied from the outside; for example, the method described in JP-A-61-147244 can be referred to.

For example, it may be ejected as a jet from a pore,
You can also wet it with a Kuep roller. Furthermore, a bottle containing water may be used in a compressed manner, and the present invention is not limited to these methods or other methods.

In the present invention, when water is supplied, it is preferable to supply water directly to the photosensitive element, but when using a dye fixing element, water is first supplied to the dye fixing element and then superimposed on the photosensitive element. Water may be absorbed into the photosensitive element by.

The water used in the present invention is not limited to so-called "pure water", but includes water in the widely conventional sense. Further, it may be an aqueous solution containing a base and/or a base precursor described below, or a mixed solvent with a low boiling point solvent such as methanol, DMF, acetone, or diisobutyl ketone. Furthermore, an aqueous solution containing an image forming accelerator and a hydrophilic heat solvent described in JP-A-61-147244 may also be used. Furthermore, the inclusion of a surfactant is advantageous in uniformly supplying water to the photosensitive element or dye fixing element.

The amount of water in the present invention is at least 0.1 times the weight of the total coating of the light-sensitive element and dye-fixing element, preferably 0.1 times the weight of the total coating of the light-sensitive element and dye-fixing element. The weight of water is within the range of 1 times to the maximum swelling volume of the entire coating film, and more preferably 0.1 times the weight of the entire coating film to the weight of water corresponding to the maximum swelling volume of the entire coating film. It is within the range of the amount obtained by subtracting the weight of the entire coating film.

The state of the film during swelling is unstable, and depending on the conditions, it may cause local bleeding.To avoid this, add water equivalent to the maximum swelling volume of the entire coated film of the photosensitive element and dye fixing element. The situation is preferable. Specifically, 1 g to 50 g, especially 2 g to 35 g, and even 3 g to 3 g per square meter of the total area of the photosensitive element and dye fixing element.
A range of 25g is preferred.

Note that a portion of the water, generally 20% or less, may be incorporated into the material.

A preferred image forming method in the present invention involves heating in the presence of a trace amount of water and a base and/or a base precursor after or simultaneously with image exposure, and at the same time as development, diffusion is generated in a portion corresponding to or inversely corresponding to a silver image. The coloring matter is transferred to the dye fixing layer. According to this method, the production or release reaction of the diffusible dye proceeds extremely quickly, and the movement of the diffusible dye to the dye fixing layer also proceeds rapidly, so that a high-density color image can be obtained in a short time.

The base and/or base precursor used in the present invention can be incorporated into both the photosensitive element and the dye fixing element. It can also be supplied dissolved in water.

In the present invention, the image forming reaction system contains, as a base precursor, a basic metal compound that is sparingly soluble in water, and a compound that undergoes a complex formation reaction with metal ions constituting the sparingly soluble metal compound using water as a medium, and then heated. It is sometimes preferable to raise the pH of the system by reaction of these two compounds.

Here, the image reaction system means a region where an image forming reaction occurs. Specifically, layers belonging to both the photosensitive element and the dye fixing element can be mentioned. If two or more layers are present, any of the layers may be used.

The poorly soluble metal compound and the complex forming compound need to be added at least in separate layers in order to prevent them from reacting before the development process. For example, in a so-called mono-sheet material in which a photosensitive element and a dye fixing element are provided on the same support, it is preferable that the above-mentioned two additive layers are separate layers, and one or more layers are interposed between them. A more preferred embodiment is one in which the poorly soluble metal compound and the complex-forming compound are contained in layers provided on separate supports. for example,
It is preferable that the poorly soluble metal compound is contained in the photosensitive element and the complex-forming compound is contained in the dye fixing element having a support separate from the photosensitive element. The complex-forming compound may be supplied after being dissolved in water to be coexisting. Hardly soluble metal compounds are disclosed in Japanese Patent Application Publication No. 5
6-174830, 53-102733, etc., and the average particle size thereof is 50 microns or less.
Particularly preferred is 5 microns or more. The poorly soluble metal compound may be added to any layer of the photosensitive element, such as the photosensitive layer, intermediate layer, or protective layer, or may be added to two or more layers separately.

The amount of a poorly soluble metal compound or complex-forming compound to be added to the layer on the support depends on the type of compound, the particle size of the poorly soluble metal compound, the rate of complex formation reaction, etc. It is appropriate to use it in an amount of 50 weight percent or less, more preferably in a range of 0.01 weight percent to 40 weight percent.

In addition, when the complex-forming compound is dissolved in water and supplied, the amount is 0.005 mol to 5 mol per liter.
, especially a concentration of 0.05 mol to 211101 is preferred. Furthermore, in the present invention, the content of the complex-forming compound in the reaction system is set at a molar ratio of 1 to the content of the poorly soluble metal compound.
/100 times to 100 times, especially 1/! 0 times or 620 times is preferable.

Examples of poorly soluble metal compounds include carbonates, hydroxides, and oxides of zinc, aluminum, calcium, barium, and the like. Regarding complex-forming compounds, see, for example, N.E. Martill, R.M. Smith (8, E.
Silk artell, R.

M, Sm1th) co-author, “Critical Stability Constances”
LyConstants) J Volumes 4-5, Blenheim Press (Plenu II Press). Specifically, aminocarboxylic acids, imidinoacetic acids, pyridylcarboxylic acids, amine phosphoric acids, carboxylic acids (mono, di, tri, tetracarboxylic acids, and more) osphono, hydroxy, oxo, ester, amide, alkoxy, mercapto, alkylthio, compounds with substituents such as phosphino), hydroxamic acids,
Examples include salts with alkali metals such as polyacrylates and polyphosphoric acids, guanidines, amidines, or quaternary ammonium salts.

The base of the present invention includes an inorganic base such as an alkali metal or alkaline earth metal hydroxide, a secondary or tertiary phosphate, a borate, a carbonate, a quinolinate, a metaborate: ammonium hydroxide hydroxides of quaternary alkylammonium; hydroxides of other metals, etc., and organic bases include aliphatic amines (trialkylamines, hydroxylamines, aliphatic polyamines): aromatic Amines (N-alkyl substituted aromatic amines, N-
Hydroxyalkyl-substituted aromatic amines and bis[
p-(dialkylamino)phenylcomethanes), heterocyclic amines, amidines, cyclic amidines, guanidines, and cyclic guanidines, and those having a pKa of 8 or more are particularly preferred.

Salts of the above-mentioned organic bases and weak acids, such as carbonates, bicarbonates, borates, secondary and tertiary phosphates, quinolates, acetates, metaborates, etc., are also preferably used.

In addition to these compounds, compounds described in JP-A-59-218443 are also preferably used.

In addition to the above-mentioned base precursors, salts of organic acids and bases that decompose by decarboxylation upon heating, compounds that decompose to release amines through reactions such as intramolecular nucleophilic substitution reactions, Rossen rearrangement, and Beckmann rearrangement. Compounds that release a base by causing some kind of reaction when heated, such as compounds that generate a base by electrolysis, etc., are preferably used. Preferred base precursors of the former type that generate a base upon heating include salts of trichloroacetic acid described in British Patent No. 998,949, etc., and U.S. Patent No. 4,060.
Salt of α-sulfonylacetic acid as described in , No. 420 of JP-A-1972
Salts of propiolic acids described in No. 9-180537, 2-carboxycarboxamide derivatives described in U.S. Pat. No. 4,088,496, and thermal decomposition using an alkali metal or alkaline earth metal in addition to an organic base as the base component. hydroxam carbamates described in JP-A-59-168-440 using Rossen rearrangement; Examples include the aldoxime carbamates described above. Others, British Patent No. 998,
No. 945, U.S. Patent No. 3,220,864, JP-A No. 5
Also useful are the base precursors described in No. 0-22625, British Patent No. 2,079,480, and the like.

The following compounds can be mentioned as compounds that generate bases by electrolysis.

For example, electrolysis of various fatty acid salts can be cited as a typical method using electrolytic oxidation.

Through this reaction, carbonates of alkali metals and organic bases such as guanidines and amidines can be obtained extremely efficiently.

In addition, methods using electrolytic reduction include the production of amines by reduction of nitro and nitroso compounds; production of amines by reduction of nitriles; nitro compounds, azo compounds,
Examples include the production of p-aminophenols, p-phenylenediamines, and dorazines by reduction of azoxy compounds and the like. p-aminophenols, p
- Phenylenediamines and hydrazines can be used not only as bases, but also directly as color image-forming substances.

Of course, it is also possible to generate an alkaline component by electrolyzing water in the coexistence of various inorganic salts.

In addition to the above, there are various methods of generating bases, and the compounds used in these methods are all useful as base precursors. For example, there is a method of generating a base by electrolysis, as described in Japanese Patent Application No. 74702/1980.

The base and/or base precursor can be used alone or in combination of two or more.

The amount of base and/or base precursor used in the present invention can be used within a wide range. When used in the photosensitive layer and/or dye fixing layer, it is appropriate to use the coating film in an amount of 50% by weight or less, more preferably 0.01% to 40% by weight. Ranges are useful. Further, when used in the present invention by dissolving in water, 0, O05rnale/
Concentrations of It to 2 mole/11 are preferred, especially 0,05 mole/ffi to 1 mole/1
A concentration of is preferred. These added amounts have no direct relationship to pH. This is because when layered with a dye fixing element, etc., the base etc. may migrate to other layers.

In the present invention, heating is performed, but since the present invention contains a solvent called water, the maximum temperature of the photosensitive element is the aqueous solution in the photosensitive element (each M1 additive is dissolved in the added water).
Determined by the boiling point of The minimum temperature is preferably 50°C or higher. The boiling point of water is 100℃ under normal pressure;
If the material is heated to a higher temperature, water may be lost due to evaporation, so it is preferable to cover the surface of the photosensitive material with a water-impermeable material. In this case, since the boiling point of the aqueous solution also rises, the temperature of the photosensitive material also rises, which is advantageous.

The heating means may be a simple hot plate, an iron, a hot roller, a heat generating plate using carbon, titanium white, etc., or the like.

Silver halides that can be used in the present invention include silver chloride, silver bromide,
Alternatively, silver chlorobromide, silver chloroiodide, or silver chloroiodobromide may be used.

Specifically, U.S. Patent No. 4,500,626, column 50, Research Disclosure June 1987 issue 9.
Pages - 10 (RD17029), JP-A-61-1072
No. 40, Patent Application No. 60-225176, No. 60-228
Any of the silver halide emulsions described in No. 267 and the like can be used.

The silver halide emulsion used in the present invention may be of the surface latent image type in which latent images are mainly formed on the grain surfaces, or may be of the internal latent image type in which the latent images are formed inside the grains. It may also be a so-called core-shell emulsion in which the inside of the grain and the surface layer of the grain have different phases. Further, in the present invention, a direct reversal emulsion in which an internal latent image type emulsion and a nucleating agent are combined can also be used.

Silver halide emulsions may be used as they are after ripening, but they are usually used after being chemically sensitized. For emulsions for conventional light-sensitive materials, well-known sulfur sensitization methods, photosensitization methods, noble metal sensitization methods, etc. can be used alone or in combination. These chemical sensitizations can also be carried out in the presence of nitrogen-containing heterocyclic compounds (JP-A-58-126526, JP-A-58-215644).
issue).

The coating amount of the photosensitive silver halide used in the present invention ranges from 1 tng to 10 g/m'' in terms of silver.

In the present invention, an organic metal salt can also be used as an oxidizing agent together with photosensitive silver halide. In this case, the photosensitive silver halide and the organic metal salt need to be in contact or at a close distance.

Among such organic metal salts, organic silver salts are particularly preferably used.

Examples of organic compounds that can be used to form the above-mentioned organic silver salt oxidizing agent include compounds described in JP-A-61-107240 and U.S. Pat. No. 4,500,626, columns 52 to 53. be.

Also useful are silver salts of carboxylic acids having an alkynyl group, such as silver phenylpropiolate described in Japanese Patent Application No. 113235/1982, and silver acetylene described in Japanese Patent Application No. 90089/1982. Two or more types of organic silver salts may be used in combination.

The above-mentioned organic silver salts contain, per mol of photosensitive silver halide,
0.01 to 10 mol, preferably 0.01 to 1
Moles can be used together. The total coating amount of photosensitive silver halide and organic silver salt is 60 mg to 10 g in terms of silver.
/m'' is appropriate.

The silver halide used in the present invention may be spectrally sensitized with methine dyes or others.

The dyes used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes.

Specifically, Japanese Patent Publication Nos. 59-180550 and 60-1
No. 40335, Research Disclosure Magazine 197
The sensitizing dyes described in June 1988 issue, pages 12-13 (RD17029), JP-A-60-111239, Japanese Patent Application No. 1983
Examples include heat-decolorizable sensitizing dyes described in Japanese Patent No. 172,967 and the like.

These sensitizing dyes may be used alone or in combination, and combinations of sensitizing dyes are often used particularly for the purpose of supersensitization.

Along with the sensitizing dye, it is a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light,
Substances exhibiting supersensitization may also be included in the emulsion (e.g., U.S. Pat. Nos. 2,933,390 and 3,635,72).
No. 1, No. 3,743,510, No. 3,615,6
No. 13, No. 3,615,641, No. 3゜617.
No. 295 and No. 3,635,721).

The stiff sensitizing dye may be added to the emulsion at or before chemical ripening, or as described in U.S. Pat. No. 4,183,
It may be carried out before or after nucleation of silver halide grains according to No. 756 and No. 4,225.666.

The amount added is generally about 10-8 to 10-2 mol per mol of silver halide.

The photosensitive element of the present invention is a dye-donating compound that produces or releases a diffusible dye in response to or inversely to this reaction when silver ions are passed through the silver under high temperature conditions. Contains sexual substances. Additionally, silver can be used as the image forming material.

Examples of the dye-donating substances used in the present invention include:
Compounds that form pigments by oxidative coupling reactions (
couplers). This coupler is 4
It may be an equivalent coupler or a 2-equivalent coupler. Also,
Two-equivalent couplers that have a diffusion-resistant group as a leaving group and form a diffusible dye by oxidative coupling reaction are also preferred. Specific examples of developers and couplers can be found in The Theory of the Photographic Process by James, 4th edition (T, 11°James ″The Theo
ry of the Photographic
Process'') pages 291-334, and 354-
361 pages, JP-A-58-123533, JP-A No. 5B-14
No. 9046, No. 58-149047, No. 59-111
No. 148, No. 59-124399, No. 59-1748
No. 35, No. 59-231539, No. 59-23154
No. 0, No. 60-2950, No. 60-2951, No. 6
No. 0-14242, No. 60-23474, No. 60-6
It is described in detail in No. 6249, etc.

Another example of the dye-donating substance is a compound that has the function of releasing or diffusing a diffusible dye in an imagewise manner. This type of compound can be represented by the following general formula (LI).

(Dye X)n Y (LI
) Dye represents a dye group, - a dye group or a dye precursor group which has been shortened in time; Inversely, a difference is created in the diffusivity of the compound represented by (Dye-X)n-Y, or Dye is released and diffusion occurs between the released Dye and (Dye X)n-Y. Represents a group having the property of causing a difference in gender, n represents 1 or 2, and when n is 2, two Dye-Xs may be the same or different.

As a specific example of the dye-donating substance represented by the general formula (LI), for example, a dye developer in which a hydroquinone developer and a dye component are linked is disclosed in US Pat. No. 3,134,764.
No. 3,362.819, No. 3,597,20
No. 0, No. 3,544,545, No. 3,482,9
It is described in No. 72, etc. In addition, a substance that releases a diffusible dye through an intramolecular nucleophilic substitution reaction is disclosed in U.S. Patent No. 3,
No. 980,479, etc., and JP-A-49-111.628, etc., disclose substances that release diffusible dyes through an intramolecular rewinding reaction of isoxacilone rings.

Another example is to make a dye-releasing compound into an oxidized form without dye-releasing ability, coexist with a reducing agent or its precursor, and after development, reduce it with the reducing agent that remains unoxidized to produce a diffusible dye. A method of releasing dye has also been devised, and a specific example of the dye-donating substance used therein is disclosed in Japanese Patent Application Laid-Open No. 53
-110,827, 54-130,927, 5
It is described in No. 6-164,342 and No. 53-35.533. Japanese Patent Application No. 60-244,873 describes a compound that releases a diffusible dye by cleavage of the N-0 bond by the remaining fueling agent as a dye-donating substance that releases a diffusible dye by a similar mechanism. Are listed.

Furthermore, as described in JP-A-59-185333, a donor-acceptor reaction occurs in the presence of a base and releases a diffusible dye, but when it reacts with an oxidized form of a reducing agent, dye release does not substantially occur. Non-diffusible compounds (LDA compounds) can also be used.

In all of these methods, the diffusible dye is released or diffused in areas where development has not occurred, and the dye is neither released nor diffused in areas where development has occurred.

On the other hand, as a substance that releases a diffusible dye in the area where development occurs, it is a coupler that has a diffusible dye as a leaving group and that releases a diffusible dye by reaction with an oxidized form of a reducing agent (DDR coupler). However, British Patent No. 1,330,52
No. 4, Special Publication No. 48-39,165, British Patent No. 3゜4
No. 43.940, etc., and is preferably used in the present invention.

In addition, in methods using these raw materials, image contamination due to oxidative decomposition products of the reducing agent becomes a serious problem. Dye-releasing compounds (DRR compounds) have also been devised and are particularly advantageously used in the present invention. Representative examples are U.S. Pat. No. 3,928,312 and U.S. Pat.
No. 53,312, No. 4,055,428, No. 4,
No. 336,322, JP-A-59-65839, JP-A No. 59
-69839, 53-3819, 51-104
, No. 343, Research Disclosure Magazine 1746
No. 5, U.S. Patent No. 3,725,062, U.S. Patent No. 3.72
No. 8,113, No. 3,443,939, JP-A-58
-116,537, 57-179840, U.S. Patent No. 4,500,626, and the like. Specific examples of this type of dye-donating substance include the aforementioned U.S. Pat. No. 4,500,626, columns 22-
List the compounds listed in column 44.

Among them, the compound described in the above-mentioned U.S. patent (1
) ~ (3), (lo) ~ (13), (16) ~ (19
), (28) to (30), (33) to (35), (
38) to (40) and (42) to (64) are preferred.

Compounds described on pages 80 to 87 of Japanese Patent Application No. 59-246468 are also useful. In addition, as a dye-donating substance other than those mentioned above, a dye silver compound in which an organic silver salt and a dye are combined (Research Disclosure Magazine 197
May 1976 issue, pp. 54-58), azo dye used in heat-developable silver dye bleaching method (US Pat. No. 4,235,957, Research Disclosure, April 1976 issue, pp. 30-32) etc.), leuco dyes (U.S. Pat. No. 3,98
5°565, 4,022,617, etc.) can also be used.

Hydrophobic additives such as the dye-providing compounds described above and the imaging promoters described below are described in U.S. Pat.
They can be incorporated into the layers of the photosensitive element by known methods such as the method described in No. 7. In this case, JP-A-59
No. -83154, No. 59-178451, No. 59-1
No. 78452, No. 59-178453, No. 59-17
No. 8454, No. 59-t78455, No. 59-178
A high boiling point organic solvent such as that described in No. 457 may be used in combination with a low boiling point organic solvent having a boiling point of 50° C. to 160° C., if necessary.

The amount of the high-boiling organic solvent is 10 g or less, preferably 5 g or less, per 1 g of the dye-providing substance used.

Also, Japanese Patent Publication No. 51-39853, Japanese Patent Publication No. 51-5994
The dispersion method using a polymer described in No. 3 can also be used.

In the case of a compound that is substantially insoluble in water, it can be dispersed and contained in the form of fine particles in the binder in addition to the method described above.

Various surfactants can be used when dispersing hydrophobic substances into hydrophilic colloids.

For example, Nos. (37) to (3) of JP-A No. 59-157636.
The surfactants listed on page 8) can be used.

In the present invention, it is desirable to include a reducing substance in the photosensitive material. Reducing substances include those generally known as reducing agents, as well as the aforementioned dye-donating substances having reducing properties.

Also included are reducing agent precursors that do not themselves have reducing properties but develop reducing properties through the action of nucleophiles and heat during the development process.

Examples of reducing agents used in the present invention include U.S. Pat.
, No. 49-5° of No. 500,626, No. 4,483 of the same.
, No. 914, columns 30-31, JP-A-60-14033
No. 5, pages (17) to (+8), JP-A-1284-1984
No. 38, No. 6゜-128436, No. 60-12843
Reducing agents described in No. 9, No. 60-128437, etc. can be used. Also, JP-A-56-138,736, JP-A-56-138,736;
Reducing agent precursors such as those described in US Pat. No. 7-40,245 and US Pat. No. 4,330,617 can also be used.

Combinations of various reducing agents can also be used, such as those disclosed in US Pat. No. 3,039,869.

In the present invention, the amount of reducing agent added is 0 per mole of silver.
．． 01 to 20 mol, particularly preferably 0.1 to 10 mol.

In the present invention, a compound that activates development and simultaneously stabilizes images can be used in the photosensitive element. For specific compounds preferably used, see U.S. Patent Nos. 4 and 5.
No. 00,626, columns 51-52.

Various antifoggants or photographic stabilizers can be used in the present invention. Examples include Research Disclosure magazine, December 1978 issue 24-2.
Azoles and azaindenes described on page 5, JP-A-59
Nitrogen-containing carboxylic acids and phosphoric acids described in Japanese Patent Application No. 168442, or mercapto compounds and metal salts thereof described in JP-A-59-111636, Japanese Patent Application No. 60-22
Acetylene compounds described in No. 8267 are used.

In the present invention, the photosensitive element may contain an image toning agent if necessary. Specific examples of effective toning agents include compounds described in JP-A-61-147244.

In order to obtain a wide range of colors in the chromaticity diagram using the three primary colors yellow, magenta and cyan, a light-sensitive element having at least three silver halide emulsion layers each sensitive to a different spectral region is used. Bye. For example, there are combinations of three layers such as a blue-sensitive layer, a green-sensitive layer, and a red-sensitive layer, and a combination of a green-sensitive layer, a red-sensitive layer, and an infrared-sensitive layer. Each of these photosensitive layers may be divided into two or more layers, if necessary.

The photosensitive element used in the present invention may contain various additives known for use in heat-developable photosensitive elements and layers other than the photosensitive layer, such as a protective layer, an intermediate layer, an antistatic layer, an antihalation layer, and a dye fixing layer. It can have a release layer, a matte layer, etc. to facilitate peeling off from the element. Various additives are listed in Research Disclosure Magazine, 1978, 6.
Plasticizers, matting agents, sharpness-improving dyes, antihalation dyes, surfactants, optical brighteners, anti-slip agents, etc. described in Japanese Patent Application Laid-open No. 61-88256, pages 9 to 15 of the Monthly issue, There are additives such as antioxidants and anti-fading agents.

In particular, the protective layer usually contains an organic or inorganic matting agent to prevent adhesion. Further, this protective layer may contain a mordant and an ultraviolet absorber. Each of the protective layer and the intermediate layer may be composed of two or more layers.

Further, the intermediate layer may contain a reducing agent to prevent color fading and color mixing, an ultraviolet absorber, and a white pigment such as titanium dioxide. A white pigment may be added not only to the intermediate layer but also to the emulsion layer for the purpose of improving sensitivity.

The photographic element of the present invention is comprised of a light-sensitive element that forms or releases a dye upon heat development and, optionally, a dye-fixing element that fixes the dye.

In particular, in systems that form images by diffusion transfer of dyes, a photosensitive element and a dye fixing element are essential.A typical example is a photosensitive element and a dye fixing element, which are attached to two supports [-]. It is roughly divided into two types: one in which it is coated on the same support, and one in which it is coated on the same support. The relationship between the photosensitive element and the dye fixing element, the relationship with the support, and the relationship with the white reflective layer is described in JP-A-61-147244, U.S. Patent No. 4.500,
The relationship described in column 57 of No. 626 is also applicable to the present application.

The dye fixing element preferably used in the present invention has at least one layer containing a mordant and a binder. As the mordant, those known in the photographic field can be used, and specific examples thereof include those described in JP-A-61-88256. The dye fixing element can be provided with auxiliary layers such as a protective layer, a release layer, and an anti-curl layer, if necessary. In particular, it is useful to provide a protective layer. One or more of the above layers may include hydrophilic heat solvents, plasticizers, anti-fade agents, UV absorbers, slip agents, matting agents, antioxidants, and dispersed vinyl to increase dimensional stability. Compounds, surfactants, optical brighteners, etc. may also be included. In addition, especially in a system in which thermal development and dye transfer are carried out simultaneously in the presence of a small amount of water, it is preferable for the dye fixing element to contain a base and/or a base precursor, which will be described later, in order to improve the storage stability of the photosensitive element. . Specific examples of these additives are described in JP-A-61-88256.

In the present invention, an image formation accelerator can be used in the photosensitive element and/or the dye fixing element. Image formation promoters include promoting redox reactions between silver salt oxidizing agents and reducing agents;
It has functions such as promoting reactions such as generation of dye from dye-donating substances, decomposition of dye, and release of diffusible dye, and promotion of transfer of dye from the light-sensitive material layer to the dye fixing layer. Based on their functions, they are classified into the aforementioned bases or base precursors, nucleophilic compounds, high-boiling organic solvents (oils), thermal solvents, surfactants, and compounds that interact with silver or silver ions. However, these substance groups generally have multiple functions and usually have some of the above-mentioned promoting effects. Details of Kowara are described in JP-A-61-93451.

Various development stoppers can be used in the photosensitive element and/or dye fixing element of the present invention in order to always obtain a constant image despite fluctuations in processing temperature and processing time during development.

The development stopper referred to here is a compound that neutralizes the base immediately after proper development or reacts with the base to lower the base concentration in the film and stop development, or a compound that inhibits development by interacting with silver and silver salts. It is a compound that Specifically, examples include acid precursors that release acids when heated, electrophilic compounds that undergo a substitution reaction with coexisting bases when heated, nitrogen-containing heterocyclic compounds, mercapto compounds, and their precursors (for example, No. 60-108837, No. 60-1
No. 92939, No. 60-230133 or No. 60-
Compounds described in No. 230134 and the like. ) Compounds that release mercapto compounds upon heating are also useful; for example, JP-A-61-67851, JP-A-61-61-
No. 147244, No. 61-124941, No. 61-1
No. 85743, No. 61-182039, No. 61-18
No. 5744, No. 61-184539, No. 61-'18
There are compounds described in No. 8540 and No. 61-53632.

A hydrophilic binder can be used for the photosensitive element and/or dye fixing element of the present invention. Typical hydrophilic binders are transparent or translucent hydrophilic binders, such as gelatin, proteins such as gelatin derivatives, cellulose derivatives, and natural substances such as starch, polysaccharides such as gum arabic, polyvinylpyrrolidone, Includes synthetic polymeric materials such as water-soluble polyvinyl compounds such as acrylamide polymers. Dispersed vinyl compounds, which are used in latex form and increase the dimensional stability of the photographic material, can also be used. These binders can be used alone or in combination.

Soukai 1 old “Ottoba!
The coating amount is preferably 10 g or less, more preferably 7 g or less.

The ratio of the high boiling point organic solvent dispersed in the binder together with a hydrophobic compound such as a dye-donating substance and the binder is 1 g of binder to 1 g of solvent or less, preferably 0.
A suitable amount is 5 cc or less, more preferably 0.3 cc or less.

The constituent layers (photographic emulsion layer, dye fixing layer, etc.) of the light-sensitive element and/or dye fixing element of the present invention may contain an inorganic or organic hardening agent.

Specific examples of hardening agents include those described in JP-A-61-147244 and JP-A-59-157636, page (38), and these can be used alone or in combination.

Further, in order to promote dye transfer, a hydrophilic thermal solvent that is solid at room temperature and soluble at high temperature may be incorporated into the photosensitive element or dye fixing element.

The hydrophilic thermal solvent may be incorporated into either the photosensitive element or the dye fixing element, or may be incorporated into both. Further, the layer to be incorporated may be any of an emulsion layer, an intermediate layer, a protective layer, and a dye fixing layer, but it is preferably incorporated in the dye fixing layer and/or a layer adjacent thereto. Examples of hydrophilic heat solvents include ureas, pyridines, amides, sulfonamides, imides, alnyls, oximes, and other heterocycles. Further, a high boiling point solvent may be included in the light-sensitive element and/or the dye-fixing element in order to promote dye transfer.

The support used in the photosensitive element and/or dye fixing element of the present invention is one that can withstand processing temperatures. As general supports, not only glass, paper, polymer films, metals and their analogs can be used, but also those described as supports in JP-A-61-147244 can be used.

The photosensitive element and/or the dye fixing element may be in the form of an electrically conductive heating layer as a heating means for thermal development or diffusion transfer of the dye.

The transparent or opaque heating element in this case can be made using conventionally known techniques for producing resistive heating elements.
As a resistance heating element, there are two methods: a method using a thin film of an inorganic material exhibiting semiconductivity, and a method using a thin film of an organic material in which conductive fine particles are dispersed in a binder. Materials that can be used in these methods include those described in Japanese Patent Application No. 151,815/1984.

In the present invention, the method of coating the heat-developable photosensitive layer, S retention layer, intermediate layer, undercoat layer, back layer, dye fixing layer, and other layers is described in U.S. Pat. No. 4,500,626, Nos. 55 to 56 III. method can be applied.

Radiation, including visible light, can be used as a light source for imagewise exposure to record an image on the photosensitive element. In general, light sources used for normal color printing, such as tungsten lamps, mercury lamps, halogen lamps such as iodine lamps, xenon lamps, laser light sources, CRT light sources, light emitting diodes (LEDs), etc.
No. 244 and No. 561g of U.S. Pat. No. 4,500.626.
The light source described in 1 can be used.

In the present invention, the steps of thermal development and dye transfer may be performed independently or simultaneously. Further, it may be continuous in the sense that transfer is performed subsequent to development in the -step.

For example, (1) after imagewise exposing and heating the photosensitive element,
There are two methods: (2) a method in which the dye-fixing elements are stacked one on top of the other and heated if necessary to transfer the diffusible dye to the dye-fixing element; and (2) a photosensitive element is imagewise exposed, and the dye-fixing elements are stacked on top of the other and heated.

The heating temperature in the heat development step can be developed at about 0°C to about 250°C, particularly about 0°C to about 180°C. When heating in the presence of water as in the present invention, the upper limit of the heating temperature is below the boiling point. When the transfer step is performed after the heat development step, the heating temperature in the transfer step is more preferably about 10° C. lower than the temperature at which transfer is possible within the range from the temperature in the heat development step to room temperature.

As a heating means in the development and/or transfer process, a hot plate, an iron, a hot roller, etc. are used.
There is a method described in No. 7244. In addition, layers of conductive materials such as graphite, carbon black, metals, etc. are applied to the photosensitive element and/or the dye fixing element,
This conductive layer may be heated directly by passing an electric current through it.

The pressure conditions and method of applying pressure when overlapping the photosensitive element and the dye fixing element and bringing them into close contact are described in Japanese Patent Application Laid-Open No. 1472-1986.
The method described in No. 44 can be applied.

Any of a variety of thermal development equipment can be used to process the photographic elements of this invention. For example, JP-A No. 59-75247,
Described in No. 59-177547, No. 59-181353, No. 60-18951, Utility Application No. 60-116734, etc.! c +-1-7″ 1.% Su Ono=
Ii? -shiA</I'+! Master! , /
Right1im='r)17-■ Specific effects of the invention According to the present invention, the photosensitive element is heated in the presence of water and a base and/or a base precursor after or simultaneously with the imagewise exposure, In the image forming method in which the generated or released diffusible dye is transferred to the dye fixing layer, the above-mentioned water is supplied from the outside and the temperature of the water is kept at 30°C or higher, so that there is no unevenness in development. , an image with sufficient density can be easily obtained in a short processing time.

(2) Specific Examples of the Invention Hereinafter, specific examples of the present invention will be shown and the present invention will be explained in more detail.

Example 1 This article describes how to make benzotriazole silver emulsion.

28 g of gelatin and 13.2 g of benzotriazole were dissolved in 300 ml of water. This solution was kept at 40°C and stirred. A solution prepared by dissolving 17 g of silver nitrate in 100 ml of water was added to this solution over a period of 2 minutes.

The pH of the benzotriazole silver emulsion was adjusted and allowed to settle to remove excess salt. Then the pH was adjusted to 6.30.
Accordingly, a benzotriazole silver emulsion with a yield of 400 g was obtained.

Next, we will discuss how to make an acetylene silver emulsion.

28 g of gelatin and 26.7 g of potassium 4-acetylaminophenylpropiolate were dissolved in 500+afi of water. This solution was kept at 40°C and stirred. To this solution, add 17 g of silver nitrate to 100 ml of water. A solution dissolved in was added over 2 minutes, and the mixture was further stirred for 10 minutes.

The pH of this emulsion was adjusted to 6.30, and centrifugation yielded 400 g of acetylene silver emulsion.

We will describe how to make silver halide emulsions for the fifth and first layers.

A well-stirred aqueous gelatin solution (containing 20 g of gelatin and 3 g of sodium chloride in 100 ml of water and kept at 75°C) contains an aqueous solution 1 & 600 ml containing sodium chloride and potassium bromide.
and a silver nitrate aqueous solution (0.59 mol of silver nitrate dissolved in 600 aIJl of water) were simultaneously added at equal flow rates over 40 minutes.

In this way, a monodisperse cubic silver chlorobromide emulsion (50 mol % of bromine) with an average grain size of 0.40 was prepared.

After washing with water and desalting, sodium thiosulfate 5B and 20 mg of 4-hydroxy-6-methyl-1,3,3a,7-titrazaindene were added to perform chemical sensitization at 60°C. The yield of emulsion was 600 g.

Next, a method for preparing a silver halide emulsion for the third layer will be described.

A well-stirred gelatin aqueous solution (20 g of gelatin and 3 g of sodium chloride in 10,100 O of water)
containing 600 mI of melon solution and kept warm at 75°C)
! , and an aqueous silver nitrate solution (0.59 mol of silver nitrate dissolved in 600 mA of water) were simultaneously added at equal flow rates over 40 minutes.

In this way, a monodisperse cubic silver chlorobromide emulsion (80 mol % bromine) with an average grain size of 0.35 was prepared.

After washing with water and desalting, 5 mg of sodium thiosulfate and 20 mg of 4-hydroxy-6-methyl-1,3,3a,7-chitrazaindene were added to perform chemical sensitization at 60°C.
The yield of emulsion was 600 g.

Next, how to make a gelatin dispersion of a dye-donating substance will be described.

5 g of yellow dye-donating substance (A), 0.5 g of sodium succinate 2-ethyl hexyl ester sulfonate, and 2 triisononyl phosphate as surfactants.
．． N star 5g, add 30al of ethyl acetate, and heat at about 60℃
The mixture was heated and dissolved to form a homogeneous solution. After lime with this solution, homogenize for 10 minutes at 10,000 rpm.
Dispersed at m. This dispersion is called a yellow dye-providing substance dispersion.

Except for using magenta dye-donating substance (B) and using 2.5g of dibutyl phthalate as a high boiling point solvent,
A dispersion of a magenta dye-providing substance was prepared in the same manner as described above.

In the same manner as the yellow dye dispersion, a cyan dye-providing substance dispersion was prepared using the cyan dye-providing substance (C).

With these, color photosensitive materials A, B, and C having multilayer structures as shown in Table 1 were prepared. The coating amounts of gelatin and polymer are as shown in Table 2 for photosensitive materials A, B, and C.

Nidibutyl phthalate, *3: 1.3-vinylsulfonyl-2-propanol, *4: (isoC911,90)3P=0, Ne5:
Size 3 to 5-1 Umbrella 6: Size 0.2 to 0.3-1 *7: Polymer table 2 Miku ■ -〇 Photosensitive materials A to C are immersed in water baths with different water temperatures for 2 seconds each, and the water temperature and The material was immediately squeezed in an environment at the same temperature to squeeze out excess water on the surface, and the amount of water absorbed by each photosensitive material was determined. The results are shown in Table 3.

Table 3 Photosensitive materials A B C water temperature
Water absorption (g/m2) 25℃ 4.8 9.5 10.430℃
6,3 13゜4 11840℃ 9.5
15.6 16.050℃ 13.5 16
．． 5 17.0 Furthermore, the time required to absorb 10 g/m' of water was determined for each light-sensitive material, and the results are shown in Table 4.

Table 4 Photosensitive material A B C water temperature
Water absorption time (seconds) 25℃ 9
2.1 1.9 30℃ 4.5 1.6 1.6 40℃ 2.5 1.3 1.3 50℃ 1.5 1.0 1.0 From the above results, it can be seen that First, it can be seen that when the water temperature is 30° C. or higher, the water absorption time can be significantly shortened.

Next, we will discuss how to make the dye fixing material.

63g of gelatin, 130g of mordant with the following structure, 1300g
mj! The solution was dissolved in water, coated on a paper support laminated with polyethylene to a wet film thickness of 42 mm, and then dried.

Mordant Further on top of this, 35 g of gelatin as a protective layer, 1.2
-bis(vinylsulfonylacetamido)ethane 4.0
A dye fixing material was prepared by applying a solution obtained by dissolving 135 g of guanidine picolinate in 800 mu of water to a wet film thickness of 17 coats and drying it.

A tungsten light bulb is used for the multilayered color photosensitive material A, and a G, R1IR three-color separation filter with continuously changing density (G is 500 to 600nII1.R is 60
0-700nIn bandpass filter, IR is 70
The film was exposed to light at 500 lux for 1 second through a filter (constructed using a filter that transmits at least 0 r++n).

This exposed light-sensitive material was immersed for 2 seconds in a bath maintained at the water temperature shown in Table 5 and then squeezed, and then stacked on dye-fixing material A so that the film surface was in contact with the material. After heating for 20 seconds using a beat roller whose temperature is adjusted so that the temperature of the water-absorbed film is 95°C, the dye-fixing material is peeled off from the light-sensitive material, and a three-color separation filter of G and RlIR is deposited on the dye-fixing material. Clear images of yellow, magenta, and cyan were obtained in response to this. Measure the maximum density (Dmax) and minimum density (Dmin) of each color using a Macbeth reflection densitometer (RD-51).
9). The results are shown in Table 5.

From the above results, it can be seen that when processing according to the present invention at a water temperature of 30° C. or higher, particularly 40° C. or higher, an even, clear, high-density image can be obtained.

Claims (1)

[Claims] A photosensitive element having at least a photosensitive silver halide, a binder and a dye-donating substance on a support is heated in the presence of water and a base and/or a base precursor after or simultaneously with imagewise exposure to produce or release In an image forming method in which a diffusible dye is transferred to a dye fixing layer,
An image forming method characterized in that the water is supplied from outside, and the temperature of the water at that time is set to 30° C. or higher.