JPS6025775B2 - Heat-developable photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-developable photosensitive material, and particularly to a raw photosensitive material (a heat-developable photosensitive material that has not been exposed and developed) at high temperatures.
This invention relates to a highly sensitive heat-developable photosensitive material with improved storage stability.

Photographic methods using silver halide have been most widely practiced since they have superior photographic properties such as sensitivity and gradation compared to methods such as electrophotography and diazo photography.

In recent years, various techniques have been developed that can obtain images maintenance-free and in real time by changing the image forming method for photosensitive materials using silver halide from wet processing using a developing solution to dry processing using heating, etc. It has been researched and developed. Currently, the most successful photosensitive materials in the field of photosensitive materials capable of forming photographic images using such dry processing methods are U.S. Pat. No. 3,152,904 and U.S. Pat.
This is a heat-developable photosensitive material using a composition containing as essential components an organic silver salt, a small amount of silver halide, and a reducing agent described in each specification of No. 075.

This photosensitive material is stable at room temperature, but after being exposed to light, it is usually heated to a temperature of 80oC or higher, preferably 100oC.
When heated to a temperature above 0.000 m, the organic silver salt oxidizing agent and reducing agent in the photosensitive layer cause a redox reaction by the catalytic action of the metal nucleus generated from the exposed silver halide present in the vicinity, producing silver. As a result, the exposed portions of the photosensitive and thermosensitive layer quickly turn black, creating a contrast with the unexposed portions (background) and forming an image. This photosensitive system uses a method in which the silver halide remaining in the photosensitive material after development is not stabilized against light and is allowed to discolor due to light, but the same effect is obtained as if it were stabilized. play.

This is because only a small amount of silver halide is used, and most of it consists of stable white or light-colored organic silver salts that do not easily darken when exposed to light, so even if a small amount of silver halide changes color due to light, the entire Because it looks white or light colored,
This is because such slight discoloration is hardly a hindrance to the viewing eye. The above heat-developable light-sensitive material is usually produced by coating a light- and heat-sensitive layer containing the organic silver salt, silver halide, and reducing agent on a support.

Various materials are used to form the support, and these are selected depending on the appearance of the photothermographic material. For example, various plastic film supports are described in JP-A No. 51-51323, but such plastic films are mainly used for making transmission-type heat-developable photosensitive materials, and are not used for ordinary copying of documents. When making reflective photothermographic materials, paper is most commonly used from the viewpoint of cost and ease of handling. Now, in order to increase the sensitivity of the photothermographic material as described above,
As in the case of conventional wet-developable silver halide-gelatin emulsions, the most effective method is to use silver halide with a large grain size.

However, if silver halide with a large grain size, especially silver halide with an average grain size of 0.05 μm or more, is used in a heat-developable light-sensitive material, it is possible to improve its shelf life under high temperatures (which can be obtained from a heat-developable light-sensitive material stored for a long period of time). Our research has revealed that there is a decrease in the photographic properties of the photographic material (characteristics that maintain the photographic properties exhibited by the photosensitive material immediately after production), particularly a decrease in maximum image density. (
Comparative example 1). It has also been found that such a tendency for deterioration of raw storage stability is more likely to occur when the support is breathable, such as paper. We discovered that it is effective to improve this drawback by providing an undercoat layer made of a copolymer of vinyl chloride and vinyl acetate or a copolymer of vinyl chloride and vinylidene chloride. Sekisho 53-18772
A patent application was filed as No. 1.

However, as a result of subsequent research, it was found that although this method significantly improved the shelf life of photothermographic materials, it caused the problem of deterioration in image quality.

That is, when a heat-developable photosensitive material in which a light-sensitive and heat-sensitive layer is coated on an undercoat layer of the above-mentioned copolymer is exposed and heat-developed, in unexposed areas and lightly exposed areas (referred to as halftone areas),
The head is dotted with dots (spots). on the other hand,
As described in JP-A No. 49-6917, by providing a protective overcoat layer on the light and heat sensitive layer of a heat-developable photosensitive material, the transparency of the light and heat-sensitive layer and the stickiness during heat development can be improved. be able to.

However, according to our experiments, when a heat-developable photosensitive material with an undercoat layer and an overcoat layer is heat-developed, a defect occurs in which a large number of bubbles are generated in the coating film of the photosensitive material. There was found. Therefore, an object of the present invention is to improve the various drawbacks that occur when an undercoat layer is provided in order to improve the shelf life of a photothermographic material, and to further expand the effects of the undercoat layer.

The present invention capable of achieving these objects has the following technical configuration.

That is, the present invention provides a support, at least [a} organic silver salt,
'c' comprises a photosensitive layer comprising a skin-sensitive silver halide and a {d} binder, and an undercoat layer provided between the support and the photosensitive layer; and 'c' a reducing agent in the support or In the heat-developable photosensitive material containing the silver halide in at least one of the layers provided on a support, the support is breathable, and the photosensitive silver halide [b] has an average grain size of 0. 05 or higher, and the undercoat layer is {
e} A photothermographic material characterized by containing at least one type of vinyl chloride polymer or vinylidene chloride polymer and a higher alcohol having an 'f' melting point of 40 qo or more. The breathable support as used in the present invention is an object having numerous small pores through which gas can flow in and out, such as paper, cloth, unglazed plates such as bricks, porous synthetic polymers, etc. represents a sheet (for example, "Micro Filter" manufactured by Fuji Film ■).

Furthermore, such supports that have been subjected to treatments other than the undercoat layer of the present invention are also included in the breathable supports referred to in the present invention. An example is processed paper. Specific examples of processed paper include coated paper; art paper; baryta paper; gelatin-primed paper; polypinyl alcohol-primed paper; glassine paper; Kent paper; paper treated with conductivity with a metal thin film or carbon;
polysaccharoid, polyvinyl alcohol, casein,
Or paper sized with carboxymethylcellulose or the like; paper treated with a calendar. In addition, the above-mentioned cloths include cloths made of natural fibers such as cotton and wool, as well as nylon,
This includes synthetic fabrics such as acrylic fibers.

As the component {e} of the pinyl chloride polymer or the vinylidene chloride polymer constituting the undercoat layer of the present invention, various examples can be given.

Namely, copolymers of polyvinyl chloride ester and pinyl chloride, copolymers of acrylic ester and vinyl chloride, copolymers of maleic ester and vinyl chloride, copolymers of fumaric ester and vinyl chloride, acrylonitrile and vinyl chloride. copolymer of vinyl alkyl ether and vinyl chloride, copolymer of vinyl chloride and vinylidene chloride, polyvinylidene chloride, copolymer of acrylonitrile and pinylidene chloride, copolymer of vinyl ester and vinylidene chloride An example is In the above, the acid constituting the vinyl ester includes carboxylic acid or sulfonic acid having 1 to 22 carbon atoms.

Specific examples of vinyl esters include vinyl acetate, vinyl stearate, vinyl butyrate, vinyl propionate, vinyl diethylsulfonacetate, and butyl vinylsulfonate. In the above, the alcohol constituting the acrylic acid ester, maleic acid ester or fumaric acid ester includes alcohols having 1 to 22 carbon atoms.

Specific examples of this alcohol include methanol, ethanol, and alcohol. Examples of these alcohols include rogol, isopropanol, butanol, isobutanol, lauryl alcohol, stearyl alcohol, and 2,3-epoxypropanol. When using copolymers, the proportions of pinyl chloride or pinylidene chloride and other monomers can be varied within wide limits.

50% vinyl chloride or vinylidene chloride (mole ratio)
The above cases are preferable. Particularly preferred is a case where vinyl chloride or pinylidene chloride accounts for 70% or more (molar ratio). In the case of a polymer of vinyl chloride and vinylidene chloride, the vinylidene chloride content is preferably 50% or more and 98% or less (molar ratio).

The degree of polymerization can vary within a wide range.

Generally, at least one copolymer selected from vinyl chloride polymers and vinylidene chloride polymers having a degree of polymerization of 30 or more is used. Preferably the degree of polymerization is 50 or more, 50,000
At least one polymer selected from the following vinyl chloride polymers and vinylidene chloride polymers is used. Other specific examples of vinyl chloride polymers and vinylidene chloride polymers include the following polymers.

Vinyl acetate-vinyl chloride copolymer, vinyl stearate-vinyl chloride copolymer, vinyl butyrate-vinyl chloride copolymer, vinyl propionate-vinyl monochloride copolymer, dimethylsulfonoacetate-vinyl chloride copolymer,
Butyl vinyl sulfonate-vinyl chloride copolymer, methyl acrylate-vinyl chloride copolymer, ethyl acrylate-
Vinyl chloride copolymer, lauryl acrylate-vinyl chloride copolymer, 2,3-epoxypropyl ester methacrylate-vinyl chloride copolymer, jetyl fumarate-vinyl chloride copolymer, jetyl maleate-vinyl chloride copolymer , dibutyl maleate-vinyl chloride copolymer, vinyl isobutyl ether-vinyl chloride copolymer, allyl 2.
3-epoxypropyl ether-vinyl chloride copolymer,
Examples include chlorophtadiene-vinyl chloride copolymer, methyl acrylate-pinylidene chloride copolymer, and ethyl methacrylate vinylidene monochloride copolymer.

Particularly preferred polymers in the present invention are vinyl acetate-vinyl chloride copolymer and vinyl chloride-vinylidene chloride copolymer.

The amount of component 'e) used in the present invention is 0.1 per pillow of support.
A range of 109 pm to 109 pm is preferred, and a range of 0.2 pm to 3 pm is particularly preferred.

By using component [f' higher alcohol as a component of the undercoat layer together with component 'd' above, both the shelf life and surface quality of the photothermographic material are dramatically improved.

The higher alcohol component [f}, which is the most characteristic feature of the present invention, is a higher alcohol having a melting point of 40 qo or higher, preferably 60 qo or higher, and the following are particularly preferred specific examples.

Namely, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecyl alcohol, eicosyl alcohol, ceryl alcohol. alcohol, mericyl alcohol, etc. The amount of component (f) used ranges from about 0.01 to about 1, preferably from about 0.05 to about 0.5, per support.

If it is too small, the area will not be improved. Further, the upper limit should be kept to an extent that does not affect photographic properties. The undercoat layer of the present invention is most commonly prepared by dissolving the above-mentioned components {e-- and other components} in an appropriate solvent and coating the solution on a support. Any known coating method may be used for coating, such as dipping method, air knife method, curtain coating, hopper coating, and extrusion coating. Examples of the solvent include cyclohexane, methylcyclohexanone, dimethylformamide, nitrobenzene, tetrahydrofuran, dibropyl ketone, methyl amyl ketone, methyl isobutyl ketone,
Examples include acetonylacetone, methyl ethyl ketone, dioxane, N.N dimethylacetamide, and mixed solvents consisting of these solvents. The undercoat layer of the present invention may contain various compounds.

For example, matting agents such as calcium carbonate, starch, titanium dioxide, zinc oxide, silica, dextrin, barium sulfate, alumina, kaolin, clay, diatomaceous earth, etc. can be included in the undercoat layer. Also, for example, West German Patent No. 972067 and West German Patent No. 1150274, French Patent No. 1530244, and US Patent No. 29333
It may contain optical brighteners such as hestilbenes, triazines, oxazoles and tocoumarins as described in the specifications of No. 9 and No. 340,607.

Further, the undercoat layer of the present invention may contain a ``compound having an effect of preventing thermal fogging on the heat-developable photosensitive material'' and a photodiscoloration inhibitor, which will be described later.

The heat-developable photosensitive material of the present invention has a photosensitive layer provided on the undercoat layer. The above-mentioned photosensitive layer means a layer containing at least component 'a} organic silver salt, component 'b} photosensitive silver halide, and component {d} binder.

However, this photosensitive layer may further contain a reducing agent and/or other additives. The organic silver salt of component (a) used in the present invention is a colorless, white or light-colored silver salt, which is heated to a temperature of 80 qo or more, preferably 10,000 qo or more in the presence of photosensitive silver halide. It sometimes reacts with reducing agents to produce silver (image).

Such organic silver salts include silver salts of organic compounds having an imino group, a mercapto group, a thione group, or a carboxyl group, and specific examples thereof include the following. '1} Examples of silver salts of organic compounds having imino groups:
Penzotriazole silvers, saccharin silvers, phthalazinone silvers, phthalimide silvers, etc. Silver salts described in Tokokukan Sho 51-22431, [2] Silver discs of compounds having mercapto or thione groups; Examples: Silver salt of 2-mercaptobenzoxazole, silver salt of mercaptooxazole, silver salt of 2-mercaptobenzothiazole, silver salt of 2-mercaptobenzimidazole, Zenishio of 3-mercapto-4-phenyl-1,2,4 triazole, etc. 1971-22431, U.S. Patent No. 39$507,
Silver salts of organic compounds having a '3' carboxyl group, such as the silver salts described in U.S. Pat. Silver, silver palmitate, silver stearate, silver arachidonic acid, silver behenate, silver aliphatic carboxylate having 23 or more carbon atoms, silver adipate, silver sebacate, silver hydroxystearate, etc. No. 22431, U.S. Patent No. 3457075, and JP-A-50-19971. Silver salts described in each specification, 'o-aromatic silver carboxylate, others: silver benzoates, silver phthalates, phenyls. Silver acetate, silver salts of 4'-n-octadecyloxydiphenyl-4-carboxylic acid, etc. silver salts described in Tokusei No. 51-22431 and JP-A-50-9971 No. 4} Other silver salts: silver salt of 4-hydroxy-6-methyl-1131$7-tetrazaindene, silver salt of 5-methyl-7-hydroxy-1,2,3,4,6-bentazaindene, etc. Examples include silver salts described in the specifications of No. 122431 and Japanese Patent Application Laid-Open No. 50-93139.

Among the organic silver salts mentioned above, organic silver salts that are relatively stable to light are particularly suitable, and among them, those having 10 to 40 carbon atoms are particularly suitable.
, preferably 18 to 33 long chain aliphatic carboxylic acids. A specific example is CH3(CH2)nCO
It is a silver salt of OH (n: 16-31), and these may be mixed. The amount of organic silver salt used is 1 for the support (described later).
The amount of silver per pillow is about 0.1 to about 4, preferably about 0.2
From evening to about 2.5 evenings. If the amount is less than this, the image density will be too low, and if it is more than this, the image density will not change but the amount of silver used will increase, resulting in high costs. There are various methods for preparing such organic silver salts, including US Pat. No. 3,457,075 and US Pat.
No. 458544, No. 3700458, No. 3839
049, British Patent No. 1405867, British Patent No. 1173
No. 426, JP-A-51-22431, JP-A-51-1
No. 22011, which are detailed in each specification.

These methods are summarized as follows. That is, an organic silver salt forming agent (for example, an imino compound, a carboxylic acid, a mercapto compound, or a salt thereof) is mixed with a suitable solvent (for example, water, aliphatic hydrocarbons, esters, ketones, halogenated hydrocarbons, ethers, Liquid A dissolved or dispersed in aromatic hydrocarbons, alcohols, oils) and silver salts that can form organic silver salts (e.g., silver nitrate, trifluoroacetic acid, silver tetrafluoride, perchloric acid) silver) in a suitable solvent (e.g. water, alcohols, acid amides, amines, aqueous ammonia, ketones,
An organic silver salt is prepared by mixing liquid B dissolved or dispersed in (acetonitrile, dimethyl sulfoxide, aromatic hydrocarbons, pyridine, aliphatic hydrocarbons). Specific examples of the above-mentioned solvents include toluene, xylene, water, cyclohexane, cyclohexene, dodecene, bentane, hexane, hebutane, butyl acetate, amyl acetate, pentyl acetate, tricresyl phosphate, castor oil, methyl alcohol, ethyl alcohol, phthalate, etc. Examples include but are not limited to propyl alcohol, butyl alcohol, acetone, dioxane, methyl ethyl ketone, methyl isobutyl ketone, methylene chloride, dibutyl phthalate, dioxane, dimethylformamide, ammonia, acetonitrile, etc.The reaction temperature is about -8000 to about The reaction time can be anywhere from about 0.01 seconds to about 15 hours, preferably about 0.1 seconds to about 7 hours. The reaction pressure is anywhere from about 10-2 feet Hg to about 30 p atm, preferably at atmospheric pressure.The concentrations of the solutions or dispersions are: Liquid A;
Both B and B can be any amount from about 10-2% to about 1% by weight, and usually from about 1% to about 5% by weight. Ultrasonic waves may be applied during the preparation of organic silver salts as described in British Patent No. 1408123. In addition, polymers, alloy metal compounds, and surfactants are added during the preparation of organic silver salts in order to change the particle morphology, particle size, and/or photographic properties such as thermal stability, photostability, photosensitivity, and fog. May exist.

Examples of polymers include polyvinyl butyral as described in U.S. Pat. 22
In addition to mercury, lead, chromium, cobalt, and rhodium as described in the specifications of JP-A No. 43, JP-A No. 50-1116024, and JP-A No. 50-11-421, manganese, nickel, iron, Cerium can also be mentioned. The amount of surfactant surfactant polymer is about 0.19 to about 100 per mole of organic silver salt.
The amount of metal-containing compound is about 10-6 mole, about 10-1 mole per mole of organic silver salt.
moles, from about 10-5 moles to about 10 moles per mole of silver halide
-2 mol range is preferred. The particle size of the organic silver salt produced in this way has a major axis of about 10 microns to about 0.5 microns.
0.1 micron, preferably about 5 micron to about 0.1 micron. The photosensitive silver halides of component {b} used in the present invention include silver chloride, silver bromide, silver iodide, silver chlorobromoiodide,
Silver chlorobromide, silver chloroiodide, silver iodobromide, or a mixture thereof. The amount used is approximately 0.001 mol per 1 mol of organic silver salt.
It ranges from about 0.7 mole, preferably from about 0.01 mole to about 0.5 mole. In the present invention, the average particle size is 0.0
Silver halide having a particle diameter of 5 or more, preferably in the range of 0.05 to 5 degrees, is used.

The average grain size of silver halide is "Mees"
), “The Theory of Photographic Process”
jc Process)''3d ed. pp36-4
3 (Mess & JamesMacMillan9)
66)". That is, the silver halide grains are photographed using a microscope (preferably an electron microscope), and the flea of the silver halide grains (if the silver halide grains are cubic, the length of the sides, if the silver halide grains are triangular plate-shaped, the length of the grains) is measured. It is determined by measuring the length of the sides and the diameter (if the shape is a hexagonal plate or sphere). When the size distribution of silver halide grains is wide, a histogram is created to find the average size, but when the size distribution is narrow, there is no need to create a histogram. The photosensitive silver halide is prepared as an emulsion by any method known in the photographic field, such as a single jet method or a double jet method.

Examples include Lippmann emulsions, ammonia method emulsions, thiocyanate or thioether ripening emulsions, and the like. Among these various emulsions, those having an average grain size of 0.05 mm or more are selected and used. The photosensitive silver halide prepared in advance in this way is mixed with a redox composition consisting of an organic silver salt and a reducing agent. No. 31 U.S. Pat.
No. 52904. Various efforts have been made to ensure sufficient contact between silver halide and organic silver salt. One is the presence of surfactants, an example of which is U.S. Pat. No. 376
Specification No. 1273, Tokusekki No. 50-32926 and No. 5
No. 0-132928 and each publication. Another method is to mix silver halides prepared in polymers with organic silver salts, e.g., US Pat. No. 3,706,566.
No. 5, No. 3706564, No. 371, and British Patent No. 136297. Another method is to enzymatically decompose a silver halide emulsion and then mix it with an organic silver salt, as described in British Patent No. 13/186. The silver halide used in the present invention is, for example, JP-A-50-1721
As described in Japanese Patent No. 6, it can also be prepared almost simultaneously with the production of organic silver salts. Still another method is to apply a photosensitive silver halide forming component (described later) to a solution or dispersion of an organic silver salt prepared in advance or to a sheet material containing an organic silver salt to form a part of the organic silver salt. It is also possible to form a photosensitive silver halide (this method is called a halide method).

It is described in US Pat. No. 3,457,075 that the silver halide thus formed is in effective contact with an organic silver salt and exhibits a favorable effect. on the other hand,
Components that can form photosensitive silver halide are compounds that produce silver halide by acting on organic silver salts, and the following simple tests can determine which compounds fall under this category and are effective. can be judged. That is, the organic silver salt is treated with a silver halide forming component, heated if necessary, and then subjected to X-ray diffraction. The purpose of this study is to investigate the presence of unique diffraction peaks in silver germide. The silver halide forming conditions are as follows.

The reaction temperature is about 18,000 to about 100 qo, preferably
It ranges from about 120°C to about 7000°C. The reaction time is from about 0.01 seconds to about 15 hours, preferably from about 0.1 seconds to about 15 hours.
Approximately 7 years old. Reaction pressure is approximately 10-2 side Hg
~300 atmospheres, preferably atmospheric pressure. Components that can form photosensitive silver halides include inorganic silver halides, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. No., U.S. Pat. No. 3,457,075, Hakama Ren Sho 50-178316, Hakama Kaisho 50-1115027, and Mochikai Sho 51-9813.

01 Inorganic halide: For example, a halide represented by MKn (where M represents day, N ratio and metal atom, x is CI, Br and 1, n is 1 when M is day, NH4 is
, When M is a metal atom, its valence is shown.

As metal atoms, lithium, sodium, potassium ~
These include cesium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, and cerium. ). ■ Onium halides: For example, quaternary halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide, etc.
quaternary phosphonium halides such as tetraethyl phosphonium bromide; tertiary sulfonium halides such as trimethylsulfonium iota 11ide, and the like. Glue Halogenated hydrocarbons: Examples include iodoform, bromoform, carbon tetrabromide, and 2-from-2-methylpropane.

'4) N-halogen compounds: N-chlorosuccinimide, N-bromosuccinimide, N-bromphthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromphthalazone, N-bromooxazolinone, N- Chlorophthalazone, N-bromoacetanilide,
Examples include N.N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 113-dibromo-4,4-dimethylhydantoin, and N-bromourazole.

[5l Other halogen-containing compounds: triphenylmethyl chloride, triphenylmethyl bromide, 2-frombutyric acid, 2
- Fromethanol, penzophenone dichloride, triphenyl bromide, etc. In the various methods described above, two or more types of silver halide forming components can be used in combination.

The amount used is approximately 0 per mole of organic silver salt of component 'a}.
．． 0.001 mole to about 0.5 mole, preferably about 0.01 mole to about 0.3 mole. If the amount is less than the lower limit above, the sensitivity will be low, and if the amount is more than the upper limit above, there will be photodiscoloration (
Undesirable background coloration (which occurs when the processed photosensitive material is left under room light) increases. In such a halide method, selection of halide temperature, pH and pAg during halide, selection of addition speed of halide agent, selection of halide agent, and dispersion of organic silver salt are performed. Halogenation generated by selecting a solvent, selecting a binder for dispersing the organic silver salt, adding a compound that forms a collar compound with silver ions, controlling defects in the organic silver salt particles by controlling the method for creating the organic silver salt particles, etc. The average particle size of silver can be increased to 0.05 or more.

The best conditions for the halide method vary greatly depending on the desired average grain size of silver halide and the type of organic silver salt used. Therefore, the best conditions for the halide method must be determined through careful experimentation.
Determining these types of conditions is easy for those skilled in the art. Regardless of the method, the produced silver halide is sensitized with, for example, a sulfur-containing compound, a gold compound, a platinum compound, a palladium compound, a silver compound, a tin compound, or a combination thereof.

Regarding these, for example, Tokusekki Sho 51-4151,
No. 51-49023, No. 51-69678, No. 51
-88216, 51-120715, 52-4
It is described in each specification of No. 821. A similar improvement in photographic properties is achieved by forming silver halide in the presence of a portion of a binder and precipitating the silver salt by centrifugation or the like, as described, for example, in JP-A-52-35623. , by applying the method of redispersion in the remaining part of the binder, ie the precipitation method in gelatin silver halide emulsion technology. Furthermore, as described in JP-A-53-28416 and U.S. Pat. No. 3,980,482, an amide compound or an imide compound may be present when a silver halide forming agent is allowed to act on an organic silver salt. It can be sensitized by

Some of the optical sensitizing dyes that are said to be effective for gelatin silver halide emulsions also exhibit a sensitizing effect on the heat-developable photosensitive material of the present invention.
It can be used to sensitize b'.

Effective optical sensitizing dyes include cyanine, merocyanine, rhodacyanine, complex (trinuclear or tetranuclear) cyanine or merocyanine, holopolar cyanine, styryl, hemicyanine, oxonol, hemioxonol, xanthene dyes, and the like. Among cyanine pigments, thiazoline nucleus, oxazoline nucleus, pyrroline nucleus,
More preferred are those having a basic nucleus such as a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, and an imidazole nucleus. Cyanine dyes having an imino group or a carboxyl group are particularly effective. In addition to the above-mentioned basic nucleus, merocyanine dyes include, for example, a thiohydantoin nucleus. It may have an acidic nucleus such as a dunnine nucleus, an oxazolidinedione nucleus, a thiazolidinedione nucleus, a barbituric acid nucleus, a thiazolineone nucleus, a malononitrile nucleus, or a pyrazolone nucleus. In particular, merocyanine dyes having an imino group or a carboxyl group are effective. As a specific example of a sensitizing dye particularly effective for the heat-developable photosensitive material of the present invention, US Pat.
No. 79, JP-A No. 50-105127, JP-A No. 50-104
Examples include merocyanine dyes having a rhodanine nucleus, a thiohydantoin nucleus, or a 2-thio-2,4-oxazolidinedione nucleus, as described in each specification of No. 637.

Other trinuclear merocyanine dyes as described in U.S. Pat. No. 3,719,495, JP-A-49-1771
sensitizing dyes mainly for silver iodide as described in No.
Rhodacyanine dyes as described in No. 77943, JP-A-49-96717 and JP-A-49-1023
Acid dyes such as 2',7-dichlorofluorescein dyes, as described in the specifications of No. 28 and British Patent No. 1417382, Samurai Seki Sho 50-15642
Merocyanine dyes such as those described in Japanese Patent Application No. 49-10168 can also be used in the present invention.

The amount of these dyes added is from about 10-4 mole to about 1 mole per mole of silver halide of component {b-, or silver halide-forming component.

The above-mentioned component 'a) and component {b}' are dispersed in a binder and coated on the undercoat layer of the present invention to form a photosensitive layer.

Suitable binders are generally hydrophobic, but may also be hydrophilic. These binders are preferably transparent or translucent, and include, for example, proteins such as gelatin, cellulose derivatives, polysaccharides such as dextran,
There are natural products such as gum arabic and other synthetic polymers. Particularly suitable binders can be selected from those described in Tokkan Sho 51-22431, among which particularly preferred binders include polyvinyl butyral, polyvinyl acetate, ethyl cellulose, polymethyl methacrylate, and cellulose. Mention may be made of acetate butyrate, gelatin, polyvinyl alcohol. If necessary, two or more types may be used in combination. The amount of binder is from about 1:1 to about 1:10, preferably from about 4:1 to about 1:4, by weight to the organic silver salt of component [a}.
Particularly preferred is a heat-developable photosensitive material in which an overcoat polymer layer is provided on the photosensitive layer described above.

This overcoat layer can increase the transparency of the photosensitive layer, increase the image density, and further improve the shelf life.
The thickness of the top coat polymer layer is about 1 micron to about 20 microns. is appropriate. Suitable polymers for the top coat polymer layer include those described in JP-A-49-6917, specifically polyvinyl chloride, polyvinyl acetate, copolymers of vinyl chloride and vinyl acetate, polystyrene, Polymethyl methacrylate, methylcellulose, ethylcellulose, cellulose acetate butyrate, cellulose acetate, polyvinylidene chloride, cell. -propionate "Cellulose acetate phthalate, polycarbonate, cellulose acetate propionate,
Examples include polyvinylpyrrolidone, polystyrene, polyvinyltoluene, nitrocellulose, styrene-isobutylene copolymers, gelatins, polymer latexes such as 2-acetoacetoxyethyl methacrylate, carboxypolyesters, and the like. If desired, the top coat polymer layer may contain carriers such as polysaccharides such as titanium dioxide, kaolin, zinc oxide, silica, alumina, and starch, making it possible to write with stamp ink, ink, ballpoint pens, pencils, etc. can.
The top coat polymer layer may also contain antihalation dyes, filter dyes, ultraviolet absorbers, acid stabilizers such as higher fatty acids, and color toning agents such as phthalazinone.
The reducing agent used in the present invention, component 'c}, preferably reduces when heated in the presence of exposed silver halide,
It is capable of reducing organic silver salt (component {a}). This component (c) is one of the essential components of Matsumoto's invention,
It may be contained in at least one of the above-mentioned layers, ie, the support, the undercoat layer, the photosensitive layer, and the topcoat layer. Suitable reducing agents include mono-, bis-, tris- or tetrakisphenols, mono- or bis-naphthols, di- or polyhydroxynaphthalenes, di- or polyhydroxybenzenes, hydroxymonoethers, ascorbic acids, 3-pyrazolidones. , pyrazolines, pyrazolones, reducing sugars, phenylenediamines, hydroxylamines, reductones, hydrooxamic acids, hydrazides, amidoximes, N-hydroxyureas, etc. Specific examples thereof include: Tokuseki Showa 51-22
431, U.S. Pat. No. 3,615,533, U.S. Pat. No. 3,679
No. 426, No. 3672904, No. 3751252
No. 3751255, No. 3782949, No. 3801321, No. 3794488, No. 38
93863, Belgian Patent No. 786086, US Patent No. 3770448, Belgian Patent No. 3819382, Belgian Patent No. 3
No. 773512, No. 3928686, No. 3839
No. 048, No. 3887378, Japanese Unexamined Patent Publication No. 50-155
No. 41, No. 50-36143, U.S. Patent No. 38278
No. 8, Japanese Patent Publication No. 50-136110, No. 50-1160
No. 2, No. 50-147711, No. 51-23721, Tokusekki No. 51-32324, and No. 51-51933. It can be selected and used as appropriate.

Particularly preferred among these compounds are polyphenols, sulfonamidophenols, and naphthols.

Preferred specific examples of polyphenols are 2,4-dialkyl-substituted orthobisphenols, 216-dialkyl-substituted parabisphenols, or mixtures thereof.

For example, 1,1-bis(2-hydroxy-3,5-dimethylphenyl)-3,5,5-trimethylhexane, 1.
1-bis(2-hydroxy-31t-butyl-5-methylphenyl)methane, 1,1-bis(2-hydroxy-315-d-butylphenyl)methane, 2,6-methylenepis(2-hydroxy-31t-butyl-5-methylphenyl)-4-methyl Phenol, 6,6-benzylidene bis(2,4-di-tert-butylphenol)
, 6,6-benzylidene bis(2-t-butyl-4-methylphenol), 6,6-benzylidene bis(2-t-butyl-4-methylphenol)
．． 4-dimethylphenol), 1,1-bis-(2-hydroxy-3,5-dimethylphenyl)-2-methylpropane, 1,1,5,5-tetrabis-(2-hydroxy-3,5-dimethylphenyl) -2,4-ethylbentane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-methyl-5-t-butylphenyl)propane, 2
．． Examples include 2-pis(4-hydroxy-3.5-di-t-butylphenyl)propane. Preferred specific examples of naphthols include 2,2'-dihydroxy-1,1'-binaphthyl, 6,6-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, and 6,6-dinitro-2,2-dihydroxy-1,1'-binaphthyl. , pis(2-hydroxy-1naphthyl)methane, 4.4'
-dimethoxy1'1'-dihydrocer-2,2-binaphthyl. Further, preferable specific examples of sulfonamide phenols include 4-benzenesulfonamide phenol, 2-benzenesulfonamide phenol,
2,6-dichloro4-benzenesulfonamidophenol is mentioned.

In addition, when using phenylene diamines as a reducing agent,
In particular, U.S. Pat. No. 3,531,286 and U.S. Pat.
In combination with phenolic or active methylene color couplers such as those described in No. 8, color images can be obtained. Similarly, U.S. Patent No. 37612
A color image can also be obtained according to the specification of No. 7B. Among the above reducing agents, examples having an alkyl group or an acyl group such as a methyl group, ethyl group, propyl group, isopropyl group, or butyl group in at least one of both substitution positions adjacent to the hydroxyl substitution position of the aromatic nucleus Mono-, bis-, tris-, or tetrakis-phenols having a 2,6-di-t-butylphenol group are most preferred because they are stable to light and have the advantage of little photodiscoloration.

Furthermore, as described in U.S. Pat. When exposed to light, it is decomposed or inactivated, and the reduction no longer progresses, so it has the advantage of eliminating photodiscoloration.

Examples of photodegradable reducing agents include ascorbic acid or its derivatives, furoin, benzoin, and dihydre. xyacetone, glyceraldehyde,. Tetrahydroxyquinone disonic acid, 4-methoxy-1-naphthol, Tokusekki Showa 50-1997
Examples include aromatic polysulfur compounds as described in No. 1 Publication. U.S. Patent Nos. 3,827,889 and 375
As described in the Specification of Han No. 29, a photothermographic material is made using such a photodegradable reducing agent, and a positive image is directly obtained by exposing the material to imagewise light to destroy the reducing agent. You can also do it. Furthermore, a compound that promotes the photodegradability of the reducing agent can be used in combination. An appropriate reducing agent is selected based on the type (performance) of the organic silver salt (component 'a}) used.

For example, stronger reducing agents are suitable for silver salts that are relatively difficult to reduce, such as silver salts of penzotriazole and silver behenate; For silver salts that are easily reduced, weaker reducing agents are suitable. Suitable reducing agents for the silver salt of penzotriazole include, for example, 1-phenyl-3-pyrazolidones, ascorbic acid, monocarboxylic acid esters of ascorbic acid, and naphthols such as 4-methoxy-1 naphthols. For silver behenate, bis(hydroxyphenyl)methane-based o-bisphenols,
There are many such as hydroquinone. Examples of silver caprate and silver laurate include substituted tetrakisphenols, bis(hydroxyphenyl)alkane o-pisphenols, p-bisphenols such as substituted bisphenol A, and p-phenylphenol. . Regarding the selection method, the easiest method for those skilled in the art would be to prepare a light-sensitive material as shown in the Examples and examine the superiority or inferiority of the reducing agent based on its photographic properties.

The amount of the reducing agent used in the present invention varies depending on the type of organic silver salt, reducing agent, and other additives, but is generally about 0.05 mol to about 10 mol per mol of organic silver salt. ,
Preferably from about 0.1 to about 3 moles are typical. Two or more of the various reducing agents mentioned above may be used in combination.

The heat-developable photosensitive material of the present invention contains the above components {a-'f
), the following additives may be added as desired to impart desired performance.

A toning agent can be used as one such additive.

This toning agent is preferably used when the resulting image is desired to be a deep-colored image, especially a black image. The amount used is about 0.0001 mol to about 2 mol, preferably about 0.0 mol per mol of organic silver salt.
0.005 moles to about 1 mole. An effective color toning agent is selected and determined depending on the type of organic silver salt and reducing agent used. Suitable toning agents include phthalazinones, oxazinediones, cyclic imides, urazoles, and 2-pyrazolin-5-ones; specific examples thereof include U.S. Pat. Nos. 3,846,136 and 3,782,941.
No. 3844797, No. 3832186, No. 3881938, No. 3 General No. 5967, British Patent No. 1 Paper No. 0795, Special Seki No. 50-1511, No. 49-91215, No. 50-1 No. 67132, 50-676
No. 41, No. 50-114217, No. 50-32 Rudder No. 7, No. 51-22431, and Mochiseki No. 52-99813, so refer to them for the colors you should use. Able to decide on dispensing. Some of them are phthalazinone, N-acetylphthalazinone, N-
Examples include hydroxyethyl phthalazinone, phthalimide, N-hydroxyphthalimide, penzoxazinedione, and uracil. One of the additives that may be added as desired is a compound having an effect of preventing heat fog on the photothermographic material.

As an example of such compounds, mention may be made of mercury compounds as described in US Pat. No. 3,589,903. Mercury compounds include mercury bromide, mercury iodide,
Mercury acetate is preferred. As a second compound that prevents heat fogging, JP-A-49-10724 and JP-A-49-9761
No. 3, No. 49-90118, and No. 51-22431, N-halogeno compounds such as N-halogenosuccinimide and N-halogenoacetamide can be used. Other compounds that prevent heat fog include U.S. Pat.
No. 01123331, No. 50-134421, JP-A No. 51-4741, No. 51-42529, No. 51-51323, No. 51-57435, No. 51-782
No. 27, No. 51-1043, No. 52-4252, etc. Compounds such as lithium salts, peroxides, persulfates, rhodium salts, cobalt salts, palladium compounds, cerium compounds , sulfinic acids, thiosulfonic acids, disulfides, rosin acids, polymer acids, etc. may also be used. Among these compounds, in particular, sodium benzenesulfinate, sodium p-toluenesulfinate, sodium benzenethiosulfonate, cerium compounds such as cerium nitrate, cerium bromide, palladium acetylacetone rust body, rhodium acetylacetone body, fatty acids etc. are preferred. Other preferred specific examples are described in JP-A-51-22431. Other examples of additives that may be added as desired include photodiscoloration of processed heat-developable photosensitive materials (a phenomenon in which the light gradually changes color when unexposed areas of the photosensitive material are exposed to room light after processing). There are compounds that are effective in preventing this.

Stabilizer precursors such as azole thioethers and blocked azolethiones, such as those described in U.S. Pat. No. 39,041;
Tetrazolylthio compound described in U.S. Pat.
No. 9624 and US Pat. No. 74,946. Gen Compound, U.S. Patent No. 3893
1-carbamoyl- described in No. 859 specification
2-tetrazoline-5-thiones, Hakama Kaisho 51-260
Single sulfur as described in Publication No. 19 can be used. In addition to the additives mentioned above, various additives known in the field of photothermographic materials may be added. Such additives can be contained in at least one layer or in two or more layers of the support, undercoat layer, photosensitive layer, and topcoat layer described above. In addition to the above-mentioned layers, the heat-developable photosensitive material of the present invention includes a vapor-deposited metal layer described in U.S. Pat. It is also possible to provide a magnetic material layer as described in Japanese Patent No. 50-13609y.

The heat-developable photosensitive material of the present invention is roughly as follows.

[A] Prepare a coating solution for undercoat layer containing component [e] and component 'f}.

Separately, an organic silver salt is produced by reacting an organic salt forming agent and a silver ion supplying agent (for example, silver nitrate) using the various methods described above.

After washing the organic silver salt thus prepared with water, alcohol, etc., it is dispersed in the component (d-binder). For dispersion, a colloid mill, mixer, ball mill, etc. can be used. A silver halide forming agent is added to the silver salt polymer dispersion thus prepared to convert a portion of the organic silver salt into silver halide. Alternatively, silver halide may be prepared in advance and added, or silver halide may be prepared simultaneously with the organic silver salt. In this way, a coating solution for a photosensitive layer is prepared. When a sensitizing dye is used, it is preferably added to the photosensitive layer coating solution in the form of a solution. Shiichi: Make a coating solution for the top coat layer.

'2} Component [c] A reducing agent is preferably added in the form of a solution to one or more of the above coating liquids (i), {o}, and (i).

In some cases, the support may be impregnated with a reducing agent. If desired, additives such as a color toning agent, a heat fog inhibitor, etc. are added to a suitable coating solution, preferably in the form of a solution.

N The coating solution prepared in this manner is coated on an air-permeable support in the order of an undercoat layer, a photosensitive layer, and an overcoat layer.

Any method may be used for application. In other words, immersion fishing method,
Coating may be carried out by air knife method, curtain coating method, hopper coating, or methods such as those described in US Pat. No. 2,761,791 and British Patent No. 837,095. Furthermore, two or more types of coating liquids may be applied simultaneously (multi-coating). If desired, the front or back side of the support, or the layer coated on the support, can be printed so that a predetermined pattern can be applied to a vehicle ticket, postcard or other document. can do.

One of the preferred embodiments of the present invention is: o Breathable support o Undercoat layer consisting of a mixture of components {el and component 'f} o
This is a heat-developable photosensitive material in which photosensitive layers consisting of components {a', 'W, 'c-' and {d-) are laminated in sequence.

Another preferred embodiment of the present invention includes: o a breathable support, o an undercoat layer containing component 'e} and component [f}, and o component [
This is a heat-developable photosensitive material in which a photosensitive layer consisting of phantom, {b}, 'c' and 'd) and an overcoat layer are sequentially layered.

Particularly preferred embodiments of the present invention include: o a support paper, o at least one copolymer selected from pinychloride-vinyl acetate copolymer or vinyl chloride-vinylidene chloride copolymer, and a higher alcohol undercoat layer having a melting point of 40°C or higher; o This is a heat-developable photosensitive material in which a photosensitive layer consisting of components Y, [b}, [c', and 'd-, and an overcoat layer are laminated in sequence.

The heat-developable photosensitive material thus produced is cut into a usable size and then imagewise exposed.

If necessary, preheating (8000 to 140°C) may be applied before exposure. Light sources used for image exposure include tungsten lamps, crab light lamps for copying such as those used mainly for fogging diazo-sensitive materials, mercury lamps, iodine lamps,
Various light sources include a xenon lamp, a CRT light source, and a laser light source. The manuscript may include not only line images such as technical drawings, but also photographic images with gradation, and it is also possible to photograph images of people and landscapes using a camera. As for the shading method, it is possible to overlap the original with a close shading, a reflective shading, or an enlarged shading. The exposure amount varies depending on the sensitivity of the photosensitive material, but for high-sensitivity ones it is about 10
lux seconds, and low-sensitivity ones require about 1 lux second.
The image-exposed photosensitive material is then heated (approximately 80°C to approximately 1
80° C., preferably about 100 qo to about 150 oo). The heating time can be arbitrarily adjusted, such as from 1 second to 6 minutes. This is determined in relation to the heating temperature. There are various means for heating, for example, the sensitive material may be brought into contact with a simple heated plate, it may be brought into contact with a heated drum, or in some cases, it may be passed through a heated space. good. Also, U.S. Patent No. 381
Heating may be performed by high frequency heating or laser beam as described in the 1885 specification. A deodorizing agent can also be provided in the processor to prevent odors generated during heating. Also, some kind of fragrance can be included so that the odor of the photosensitive material is not detected. In order to further stabilize the heat-developable photosensitive material thus processed against light and heat after processing, various methods such as those described below may be applied.

For example, U.S. Pat.
No. 4826: A method of stabilizing a heat-developable photosensitive material by treating it with a solution containing a thiosulfate, thiocyanate, triphenylphosphine, mercapto compound, etc. as described in each specification; JP-A-51-80226. Method of stabilizing with an aldehyde compound described in Tsubaki Kaisho No. 50-15432, No. 50-177034, No. 50-156
No. 425, No. 51-328, and No. 51-121332, for example, a layer containing a stabilizer such as a mercapto compound or a halogen-containing compound is added to a heat-developable photosensitive material after, before, or during processing. There are methods for stabilizing it by applying it to The heat-developable photosensitive material according to the present invention can be used for various purposes other than ordinary calligraphy and painting reproduction, and is therefore very useful.

For example, US Pat. No. 3,607,282, US Pat. No. 3,58990
Directly assisted positive images can be recorded as described in each specification of No. 1, and as described in Samurai Seki No. 47-465y, U.S. Patent No. 3,679,414, and U.S. Pat. It can be used as a lithographic printing plate as shown in U.S. Pat. No. 3,767,394, U.S. Pat. It can also be applied to commuter passes as described in Japanese Patent Application Laid-open Nos. 50-87318, 50-125737, and Tsubaki Publication No. 51-4107. The heat-developable photosensitive material of the present invention has the effect of improving raw storage stability at high temperatures by providing an undercoat layer made of a vinyl chloride polymer or a vinylidene chloride polymer, and is also made of such a polymer. This improves the problem of spot generation caused by the undercoat layer, and by providing an overcoat layer, the transparency of the photosensitive layer is improved, the stickiness of the coating film is improved, the image density is increased, and the shelf life is improved. At the same time as the advantages, there are disadvantages due to the structure in which the photosensitive layer is sandwiched between an undercoat layer and an overcoat layer.
That is, this solution solves the problem of foaming during thermal development. Therefore, the present invention makes it possible for the first time to obtain a heat-developable photosensitive material that is excellent in both raw storage stability and image quality. The present invention will be explained in more detail with reference to Examples below.

EXAMPLE 340 ml of behenic acid was added to 5,000 ml of water and heated to 85°C to melt.

(referred to as liquid A) Separately add 20 parts of sodium hydroxide to 50 parts of water.
An aqueous solution of 0.0% was prepared. (Referred to as liquid B.
) Solution A was heated to 85 qo, and solution B was added to the fly at a rate of 100 qo per minute.

A mixed dispersion of sodium behenate-behenic acid was obtained. (Referred to as liquid C.) 30o0 while continuing to pump liquid C.
Cooling was kept constant.

Separately, an aqueous solution was prepared by dissolving 85 parts of silver nitrate in 500 parts of water.

(referred to as Liquid ○) Liquid D was added to Liquid C at a rate of 100 ships per minute to obtain a dispersion containing silver behenate {E}.

Dispersion E was left in a light frame for 90 minutes at 30oo.

Next, 40 parts of polyvinyl butyral was added to 1 part of isoamyl acetate.
The liquid leg dissolved in 000 Z was added and heated at 30qC for 10 minutes. Then, immediately after settling, the liquid phase portion was removed and the solid phase portion was centrifuged (300 ratio, p.m. for 30 minutes).
After adding 1 powder, mix with a solution of 270% polypynyl butyral dissolved in 1800% isopropanol,
Dispersion was performed using a homogenizer for 60 minutes. In this way, a uniform polymer dispersion containing behenic acid and behenic acid (referred to as liquid G) was obtained. Keeping the liquid G at 50:0, add 160:0 of a 4.2% by weight acetone solution of N-furomosuccinimide (silver halide forming agent) to the lantern.
The reaction was allowed to proceed for 0 minutes to form silver bromide (average particle size approximately 0.07 microns) that was catalytically contacted with a portion of the silver behenate. The silver behenate-silver behenate monobromide polymer dispersion thus formed is hereinafter referred to as a liquid solution. liquid day 30
The coating solution was prepared by maintaining the temperature at 0.000000000000000000000000000000000000000000000000000000000000000000000 note level picture of next ingredient at 5 minute interval. i) Sensitizing dye (formula below) (0.0
25wt% ethylene glycol monomethyl ether liquid)
240 secretion ii) Sodium benzenethiosulfonate (antifogging agent) (0.01wt% methanol solution) 240 above iii) m-nitrobenzoic acid (antifogging agent) (0.5wt% ethanol solution)
240 machines [iV] Phthalazinone (color toning agent)
(4.5 wt% ethylene glycol monomethyl ether solution) 600'V) Reducing agent (formula below) (1 K% acetone solution) 960
A total silver content of 0 on a support with the various undercoating layers shown in the table.
．． It was coated so as to form a support of 4 ta'.

After drying (1 minute at 70 qC), a top coat layer was formed by applying a solution prepared by dissolving 45 parts of cellulose diacetate in a mixed solvent of 810 parts of acetone and 90 parts of ethanol to a dry film thickness of about 1 micron. Dry at 50qo for 1 minute.
Heat-developable photosensitive materials (1) to (2) were prepared. Each sample in Table 1 was divided into two parts, and one part was given a light intensity of 30,000 lux·sec, which is enough to obtain Dmax, from a tungsten light source through an optical wedge, and then developed by heating at 130° C. for 8 seconds.

The other one was stored in a 3530 in an atmosphere of 80% RH for one week (to check its viability), and then exposed and developed in the same machine.

The results are shown in Table 2. Table 2 In the above table

Claims (1)

[Claims] 1 a support, at least a photosensitive layer comprising (a) an organic silver salt, (b) a photosensitive silver halide, and (d) a binder; and an undercoat layer provided between the support and the photosensitive layer; and (c) a heat-developable photosensitive material containing a reducing agent in the support or in at least one of the layers provided on the support, wherein the support is breathable;
b) Photosensitive silver halide has an average grain size of 0.05μ
Thermal development according to the above, and wherein the undercoat layer contains (e) at least one type of vinyl chloride polymer or vinylidene chloride polymer and (f) a higher alcohol having a melting point of 40° C. or higher. photosensitive material.