JP2699230B2 - Photothermographic material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material capable of obtaining an image having excellent discrimination. Further, the present invention relates to a heat-developable color light-sensitive material capable of obtaining an excellent color image in a short time and capable of reducing the size and weight of the apparatus.

[0002]

2. Description of the Related Art A latent image is formed by imagewise exposing a photosensitive material having a photosensitive layer containing a photosensitive silver halide on a support, and then a latent image of silver halide is formed by thermal development. An image forming method for forming an image on a portion is disclosed in
947, etc. Further, a latent image is formed by imagewise exposing a photosensitive material having a photosensitive layer comprising a photosensitive silver halide, a reducing agent, a polymerizable compound and a binder on a support to form a latent image. An image forming method for forming a polymer compound in a portion where a latent image is formed is described in JP-A-61-69062 and the like.

Further, a light-sensitive material in which silver halide, a reducing agent, a color image-forming substance, and a polymerizable compound are contained in microcapsules (capsules containing light-sensitive materials such as silver halide are called photosensitive microcapsules). Are disclosed in JP-A-61-275742 and JP-A-61-278849.
No., published in Japanese Unexamined Patent Publication No. As an image forming method using the photosensitive material having the above configuration, a latent image is first formed by imagewise exposing the photosensitive material, and then the latent image is thermally developed to form an image or color on a portion where the latent image is formed. A method is generally used in which an image forming substance is formed and sometimes transferred to an image receiving material to obtain a transferred image on the image receiving material.

Japanese Patent Application Laid-Open No. 61-27574 discloses silver halide grains used in such an image forming method by thermal development.
Silver iodobromide emulsions prepared to contain a high proportion of iodine on the surface as described in No. 2 are used.
These emulsions have low fog in the image forming method by thermal development, and as a result, a good image of discrimination having a high maximum image density and a low minimum image density can be obtained.

On the other hand, in an equipment system using these photosensitive materials, an exposure step, a heat development step, and a subsequent pressure transfer step are continuously performed. In particular, in order to reduce the size of the apparatus in the exposure step, and further to shorten the processing time, it is desirable that the sensitivity of these photosensitive materials be high.

As a means for increasing the sensitivity of silver halide, means of chemical sensitization is generally known in the art. This is a means for increasing the efficiency of forming latent images of silver halide grains and increasing the sensitivity by adding sulfur compounds and noble metal compounds after desalting silver halide grains. These methods increase the sensitivity of ordinary silver halide sufficiently, however,
In the case of a silver iodobromide emulsion prepared so as to include a layer having a high silver iodide content on the surface used for the photothermographic material, the sensitivity was not sufficiently increased by ordinary chemical sensitization.

It is well known in the art that silver iodobromide emulsions prepared so as to include a layer having a high silver iodide content near the surface are generally difficult to chemically sensitize in the art. In the case of a photothermographic material, unless a silver iodobromide emulsion prepared so as to include a layer having a high silver iodide content near the surface is used, a good image of discrimination with less fog can be obtained. Development of an emulsion satisfying these conflicting requirements has been desired.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photothermographic material capable of obtaining an image having excellent discrimination in a short time. In particular, it is an object of the present invention to provide a photothermographic material capable of obtaining an image with high sensitivity and excellent discrimination. An object of the present invention is to provide a photothermographic material having excellent storage stability. Another object of the present invention is to provide a photothermographic material which is capable of rapid thermal development at a relatively low temperature and whose photographic performance is hardly changed even when the development temperature fluctuates.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a silver halide emulsion containing silver halide grains containing a layer having a high silver iodide content on the surface of the grains, and to provide desalting and iodine ionization. This has been attained by a photothermographic material comprising at least one silver halide emulsion characterized by being subjected to chemical sensitization before addition. A preferred embodiment of the present invention is a photothermographic material comprising at least one silver halide emulsion characterized in that a sensitizing dye is added before desalting in the production of the silver halide emulsion. is there. Further, a preferred embodiment of the present invention is characterized in that in the production of the silver halide emulsion, at least one kind of silver halide emulsion characterized in that the conductivity after desalting is 6 mScm ^-1 or less. It is a photosensitive material.

In a photosensitive material having a photosensitive layer containing photosensitive microcapsules containing at least a silver halide, a reducing agent, a polymerizable compound, and a color image forming substance on a support, the silver halide This has been attained by a photothermographic material characterized by containing at least one emulsion.

The photosensitive material used for the silver halide of the present invention will be described below. Here, silver halide, a reducing agent, a color image forming substance, a base precursor, a microcapsule, and a support used for a photothermographic material (hereinafter simply referred to as a "photosensitive material") will be particularly described. It goes without saying that the present invention can be applied to photosensitive materials other than photosensitive materials. As the silver halide emulsion contained in the photosensitive microcapsules of the present invention, any of silver chloroiodide, silver bromoiodide and silver chloroiodobromide can be used.

The silver halide grains have regular crystals such as cubic, octahedral, dodecahedral, and tetradecahedral,
Those having an irregular crystal system such as a sphere or a plate, those having a crystal defect such as a twin plane, or a composite thereof may be used. The grain size of the silver halide may be fine grains of about 0.01 μm or less or large grains having a projected area diameter of about 10 μm, and may be a polydisperse emulsion or US Pat. No. 3,574,628. 3,655,394
And the monodisperse emulsions described in British Patent No. 1,413,748 and the like. Tabular grains having an aspect ratio of about 5 or more can also be used in the present invention. Tabular grains are described in Photographic Science and Engineering (Gutoff, Photographic
Science and Engineering), Vol. 14, 248-257
P. (1970); U.S. Patent No. 4,434,226;
Nos. 4,414,310, 4,433,048, 4,439,520 and British Patent 2,112,1
It can be easily prepared by the method described in No. 57 or the like.

The internal crystal structure may be uniform, the interior and exterior may be composed of different halogen compositions, or may have a layered structure, but the outermost part has a high iodine content. With layers. Further, silver halides having different compositions may be bonded by epitaxial bonding, or may be bonded to a compound other than silver halide such as, for example, silver rhodan or lead oxide. Further, two or more kinds of silver halide grains having different halogen compositions, crystal habits, grain sizes and the like can be used in combination. Silver halide photographic emulsions that can be used in the present invention include, for example, Research Disclosure (RD) No. 17643 (December, 1978), 22-
Page 23, "I. Emulsion preparation and
types) "and No. 18716 (November 1979
), P. 648, and the like. A layer having a high silver iodide content at the outermost part of the silver halide emulsion of the present invention is prepared by adding only iodide ions after grain formation, iodide ions and silver ions simultaneously, or by adding AgI fine grains prepared in advance. it can. The iodide ion is added as an aqueous solution of a salt with an alkali metal cation, and among them, an aqueous solution of potassium iodide or sodium iodide is preferred.

As a method of adding iodine ions, the whole amount may be added with a Kippen, or the amount may be controlled to be constant per hour. However, not only the addition rate but also the temperature, stirring, and other conditions are controlled. Is preferred. Preferred addition conditions are as follows: temperature is 30 ° C. to 75 ° C., and silver in the emulsion is 1 mole, and the addition rate is 1 × 10 ⁻⁵ per minute.
To 1 × 10 ⁻² mol, more preferably at a temperature of 35 ° C. to 50 ° C., at a rate of 1 × 10 ⁻⁴ to 1 × 10 ⁻³ per minute.
Add moles. The amount of iodine ion added to form the outermost silver iodobromide layer is 0.01 mol% to 50 mol%, preferably 0.5 mol%, based on silver of all silver halide grains. It is preferred to add from 1 to 10 mol%, more preferably from 1 to 5 mol%.

The chemical sensitization of the silver halide emulsion is carried out before the addition of iodine ions. Additives used in chemical sensitization are Research Disclosure No. 17643 and No. 18
716, and the relevant locations are described in the table below. Preferably, sensitization with gold and sulfur is performed. Conditions for performing the chemical sensitization are as follows:
To 80 ° C, pH 4 to 10, pAg 7 to 10, time 1
0 minutes to 120 minutes is preferred. More preferably, a temperature of 60
C. to 75.degree. C., pH 5 to 8, pAg 8 to 9, time 30 to 80 minutes are good. The spectral sensitization of the silver halide emulsion may be performed before or after the chemical sensitization or before or after the addition of iodide ions, as long as it is before the desalting step. It is better to do it before addition. Research Disclosure Additives Used in Spectral Sensitization
No. 17643 and No. 18716,
The relevant locations are described in the table below. Conditions for performing the spectral sensitization include a temperature of 40 ° C. to 80 ° C. and a pH of 4-1.
0, pAg 7 to 10 and time 1 to 60 minutes are preferred. More preferably, the temperature is from 60 ° C. to 75 ° C., pH 5 to 8, p
Ag 8-9, time 5-30 minutes is good.

The silver halide emulsion of the present invention is preferably desalted so that the electric conductivity at 40 ° C. becomes 6 mScm ⁻¹ or less. The desalination method is Research Disclosure No.1
Any of the methods described on pages 7643 and 23 may be used, but after adding a flocculant for gelatin, the pH is adjusted to precipitate the emulsion, the supernatant containing salt is removed, and water is added. It is preferable to use a so-called flocculation method in which washing and re-sedimentation of the emulsion are repeated. In the present invention, the conductivity after desalting is set to 6 mScm ^-1 or less, preferably 0.5 to 5 mScm ^-1 , more preferably 1 to 4 mScm ^-1 .
Scm ^-1 is good.

The silver halide emulsion is usually subjected to various ripenings. Additives used in such aging are research and
Disclosure No.17643 and No.18716
The relevant locations are summarized in the table below. Known photographic additives that can be used in the present invention are also described in 2 above.
Listed in two research disclosures,
The relevant places are shown in the table below. Additive type RD17643 RD18716 Chemical sensitizer page 23, page 648, right column Sensitivity enhancer Same as above Spectral sensitizer page 23-24 page 648, right column Superstrong sensitizer page 649, right column Antifoggant page 24-25 649 The right column of the page and stabilizers The details of the silver halide emulsion and photographic additives are described in the above-mentioned "Known Technique No. 5", pp. 2-17. The amount of silver halide used is 0.001 to 10 g, preferably 0.05 to ² g, in terms of silver per m ² of the light-sensitive material.
g. In the present invention, an organic silver salt can be used for both silver halides. The organic silver salt is described in “Known Technique No. 5” (Aztec Co., Ltd., issued on March 22, 1991), pp. 17-18.

The reducing agent that can be used by being housed in the photosensitive microcapsule of the present invention has a function of reducing silver halide and / or a function of accelerating (or suppressing) polymerization of a polymerizable compound. Examples of the reducing agent having the above function include hydroquinones, catechols, p-
Aminophenols, p-phenylenediamines, 3-
Pyrazolidones, 3-aminopyrazoles, 4-amino-5-pyrazolones, 5-aminouracils, 4,5-
Dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- or p-sulfonamidophenols, o- or p-sulfonamidonaphthols, 2,4-disulfonamidophenols, 2,
4-disulfonamidonaphthols, o- or p-acylaminophenols, 2-sulfonamidoindanones, 4-sulfonamido-5-pyrazolones, 3-sulfonamidoindoles, sulfonamidopyrazolobenzimidazoles, There are sulfonamidopyrazolotriazoles, α-sulfonamidoketones, hydrazines and the like.

The above various reducing agents are described in detail in the above-mentioned “Known Technique No. 5”, pp. 18-35. The amount of the reducing agent to be added can be varied widely, but is generally from 0.1 to 1500 mol%, preferably from 10 to 300 mol%, based on the silver salt. The color image forming substance that can be used in the light-sensitive material of the present invention is not particularly limited, and various types can be used. That is, it is a substance that is colored by itself (dye or pigment), is itself colorless or pale color, but has external energy (heating, pressurizing, light irradiation, etc.) or another component (color developer). A substance (color-forming agent) that forms a color by contact with is also included in the color image forming substance. As the color image forming substance of the present invention, as described in JP-A-62-187346, dyes and pigments which have excellent image stability and are themselves colored are preferred.

As the color image forming substance used in the present invention, as dyes and pigments, commercially available ones and known ones described in various documents can be used. For literature, refer to Color Index (CI) Handbook, “Latest Pigment Handbook”, edited by Japan Pigment Technology Association (1977), “Latest Pigment Application Technology”, CMC Publishing (1986), “Printing Ink Technology” (CMC Publishing). 1984). The details of the color image forming substance that can be used in the present invention and the technique of using the same are described in the above-mentioned “Known Technique No. 5”, pp. 35-50. In particular, pigments are preferable because of their excellent light fastness. The pigment is 5 to 6 parts by weight based on 100 parts by weight of the polymerizable compound.
It is preferable to use 0 parts by weight.

As the base precursor that can be used in the light-sensitive material of the present invention, base precursors of an inorganic base and an organic base (decarboxylation type, thermal decomposition type, reaction type, complex salt forming type, etc.) can be used. Details of these base precursors and the techniques for using them are described in the above-mentioned “Known Technique No. 5”.
No., pp. 55-86. Preferred base precursors are described in JP-A-59-180549, JP-A-59-180537, JP-A-59-195237, and JP-A-59-195237.
Nos. 1-32844, 61-36743 and 61-5
No. 1140, No. 61-52638, No. 61-5263
9, No. 61-53631, No. 61-53634,
Nos. 61-53635, 61-53636, 61
-53637, 61-53638, 61-53
Nos. 639, 61-53640, 61-55644
Nos. 61-55645, 61-55646, 61-84640, 61-107240, and 61
-219950, 61-251840, 61-
No. 252544, No. 61-313431, No. 63-3
No. 16740, No. 64-68746 and Japanese Patent Application No.
No. 54452, JP-A-59-155763, salts of organic acids and bases which are decarboxylated by heating.
No. 7, 59-166943 and 63-96159, compounds which release a base by heating.

The base precursor of the present invention includes 50
It is preferred to release the base at a temperature of
More preferably, it is released at a temperature of from 180 ° C to 180 ° C. The base precursor used in the light-sensitive material of the present invention is contained in a photosensitive microcapsule.
As described in No. 70159, a base precursor composed of a salt of a carboxylic acid and an organic base having a solubility of 1% or less in water and a polymerizable compound at 25 ° C. is particularly preferable.

In the case where the base precursor is contained in the microcapsules in the present invention, a photosensitive composition in which the base precursor is directly solid-dispersed in a polymerizable compound may be used (Japanese Patent Application Laid-Open No. Sho 64-32251; Kaihei 1-2
It is particularly preferable to use a photosensitive composition in which a base precursor is dispersed in water and emulsified in a polymerizable compound. (JP-A-63-21
8964, JP-A-2-14641, JP-A-3-2
For the dispersion of the base precursor in water, a nonionic or amphoteric water-soluble polymer described in “Known Technique No. 5”, pp. 128 to 135, can be used. .

The water-soluble polymer is preferably contained at a ratio of 0.1 to 100% by weight, more preferably at a ratio of 1 to 50% by weight, based on the base precursor. Further, the base precursor is preferably contained in an amount of 5 to 60% by weight, more preferably 10 to 50% by weight, based on the dispersion. Further, the base precursor is preferably contained in a ratio of 2 to 50% by weight based on the polymerizable compound,
More preferably, it is contained at a ratio of 5 to 30% by weight.

Various known techniques can be applied to the microcapsules that can be used as the photosensitive microcapsules that can be used in the present invention, without any particular limitation. The method described can be used. In the present invention, it is particularly preferable to use a melamine-formaldehyde resin, since a highly dense capsule can be obtained. Japanese Patent Application Laid-Open No. 2-216151 discloses, in order to obtain a capsule having particularly excellent wall denseness, a reaction product of a water-soluble polymer having a sulfinic acid group and a polymerizable compound having an ethylenically unsaturated group. A microcapsule in which a polymer wall of a high molecular compound such as a melamine / formaldehyde resin is provided around a membrane is disclosed, and is preferable in the present invention.

When an aminoaldehyde-based microcapsule is used, it is preferable that the amount of residual aldehyde is not more than a certain value, as in a photosensitive material described in JP-A-63-32535. The method is described in JP-A-63-14.
No. 2343 and the like. The average particle size of the photosensitive microcapsules is 1 to 50 μm, preferably 3 to 25 μm.
μm. It is preferable that the distribution of the particle diameter of the photosensitive microcapsules is uniformly distributed to a certain value or more as in the photosensitive material described in JP-A-63-5334.
The thickness of the photosensitive microcapsule is described in
As in the light-sensitive material described in JP-A-81336, it is preferable that the particle diameter is within a certain range.

When silver halide is contained in the microcapsules, the average grain size of the silver halide grains is preferably one-fifth or less of the average size of the photosensitive microcapsules. More preferably, it is set to 1 or less. By setting the average grain size of the silver halide grains to one fifth or less of the average size of the microcapsules, a uniform and smooth image can be obtained. When silver halide is contained in the microcapsules, it is preferable that silver halide be present in the wall material constituting the outer shell of the microcapsules. The photosensitive material containing silver halide in the wall material of the microcapsule is described in JP-A-62-169147.

In the production of the photosensitive microcapsule of the present invention, an oily liquid comprising a silver halide, a reducing agent, a color image-forming substance and a polymerizable compound containing a base precursor is dispersed in an aqueous medium, and the outer shell of the capsule is formed. In the formation, the aqueous medium preferably contains a nonionic water-soluble polymer and an anionic water-soluble polymer. In this case, the amount of the oily liquid containing the polymerizable compound is preferably 10 to 120% by weight based on the aqueous medium, and 20% by weight.
~ 90 wt% is more preferred.

Examples of nonionic water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polymethylvinyl ether, polyacryloylmorpholine, polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate-co-acrylamide, hydroxyethyl cellulose, hydroxyethyl cellulose, and the like. Propyl cellulose and methyl cellulose can be exemplified. Examples of the anionic water-soluble polymer include polystyrene sulfinic acid, a copolymer of styrene sulfinate, a polystyrene sulfonate, a copolymer of styrene sulfonic acid, polyvinyl sulfate, polyvinyl sulfonate, and maleic anhydride. -Styrene copolymers, maleic anhydride-inbutylene copolymers and the like can be mentioned. In this case, the concentration of the anionic water-soluble polymer in the aqueous medium is preferably in the range of 0.01 to 5% by weight, and more preferably in the range of 0.1 to 2% by weight. In the above case, it is particularly preferable to use a nonionic water-soluble polymer in combination with a water-soluble polymer having a small amount of sulfinic acid groups. Further, in order to reduce the solubility of the base precursor in the polymerizable compound, in the polymerizable compound, polyethylene glycol, polypropylene glycol, benzoic acid amide, cyclohexylurea, octyl alcohol, dodecyl alcohol, stearyl alcohol, -OH such as stearoamide,-. SO ₂ NH ₂ , −
A compound having a hydrophilic group such as CONH ₂ or —NHCONH ₂ can also be added.

In the present invention, in addition to the above-mentioned reducing agent, a known antioxidant for preventing the polymerizable compound from being oxidatively degraded and for preventing oxygen oxidation during thermal development can be used together with the polymerizable compound. Such antioxidants include 2,2 '
-Methylene-bis- (4-methyl-6-t-butylphenol), 2,6-di-t-butylphenol, 2,
2'-butylidene-bis- (4-methyl-6-tert-butylphenol), 2-tert-butyl-6- (3'-tert-butyl-5'-methyl-2'-hydroxybenzyl) -4
Phenolic antioxidants such as -methylphenyl acrylate and 4,4'-thio-bis- (3-methyl-6-t-butylphenol); diphenyldecyl phosphite;
Triphenyl phosphite, tris- (2,4-di-t
Phosphite-based antioxidants such as -butylphenyl) phosphite and tris- (2-ethylhexyl) phosphite; dilauryl-3,3'-thio-dipropionate, pentaerythritol-tetrakis- (β-lauryl-thio) -Propionic acid esters), thio-dipropionic acid and the like; sulfur-based antioxidants; phenyl-1-naphthylamine, 6-ethoxy-2,2,4-trimethyl-
Examples include amine antioxidants such as 1,2-dihydroquinoline and dioctyliminodibenzyl.

Materials that can be used for the support include glass, paper, woodfree paper, baryta paper, coated paper, cast coated paper, synthetic paper, metal and analogs thereof, polyester, polyethylene, polypropylene, acetylcellulose, and cellulose. Esters, polyvinyl acetal,
Examples include films of polystyrene, polycarbonate, polyethylene terephthalate, polyimide, and the like, and papers laminated with resin materials and polymers such as polyethylene. For details, refer to “Known Technique No. 5
No. ", pages 144 to 149. Among these, a preferred support of the present invention is a polymer film, and from the viewpoint of the thermal conductivity described above, a polymer film of 50 μm or less is particularly preferred.

In order to further coat the photosensitive layer on the support,
It is preferable to provide an undercoat layer described in JP-A-61-113058 on a polymer film, or to provide a metal vapor-deposited film of aluminum or the like on the polymer film.
Therefore, as a support for the photosensitive material of the present invention, 50 μm
A polymer film having a thickness of not more than m and having an aluminum deposition film is particularly preferable.

Hereinafter, other components that can be used in the light-sensitive material of the present invention will be described. Details of these components are described in the above-mentioned “Known Technique No. 5”, pp. 98-144 and 86-
It is described on page 88. The binder that can be used in the photosensitive material can be contained alone or in combination in the photosensitive layer. It is preferable to use a hydrophilic binder mainly. Representative examples of the hydrophilic binder include transparent or translucent hydrophilic binders, such as natural substances such as gelatin, gelatin derivatives, cellulose derivatives, starch, and gum arabic, and polyvinyl alcohol, polyvinylpyrrolidone, and acrylamide polymers. And synthetic polymer materials such as water-soluble polyvinyl compounds. Other synthetic polymeric substances include dispersed polyvinyl compounds which increase the dimensional stability of the photographic material, especially in the form of a latex. The photosensitive material using a binder is described in JP-A-61-69062. Japanese Patent Application Laid-Open No. 62-209525 discloses a photosensitive material using a binder together with microcapsules.
There is a description in the publication.

As the anti-smudge agent used in the light-sensitive material, a particulate solid at ordinary temperature is preferable. Specific examples include starch particles described in British Patent No. 12323347, polymer fine powder described in U.S. Pat. No. 3,625,736, and microcapsule particles containing no color former described in British Patent No. 1235991. US Patent No. 2
Examples include cellulose fine powder, inorganic particles such as talc, kaolin, bentonite, pyroxene, zinc oxide, titanium oxide, and alumina described in the specification of Japanese Patent No. 71375. The average particle size of the above particles is preferably in the range of 3 to 50 μm in terms of volume average diameter, more preferably in the range of 5 to 40 μm. As described above, when the oil droplets of the polymerizable compound are in the form of microcapsules, it is more effective that the particles are larger than the microcapsules. Various image formation accelerators can be used for the photosensitive material.

The image formation accelerator has a function of accelerating the transfer of a base or a base precursor, promoting the reaction of a reducing agent with a silver salt, and promoting the immobilization of a dye-donating substance by polymerization. Are classified into the above-mentioned bases or base precursors, nucleophilic compounds, oils, thermal solvents, surfactants, compounds interacting with silver or silver salts, compounds having an oxygen removing function, and the like. However, these substance groups generally have a composite function and usually have some of the above-mentioned promoting effects. Details of these are described in specifications and gazettes such as U.S. Pat. No. 4,678,739, columns 38 to 40 and JP-A-62-209443. Hexavalent metal compounds described in Japanese Patent Application No. 2-2727878 are also effective.

In a system in which a polymerizable compound in a portion where a latent image of silver halide is not formed is polymerized,
A heat or photopolymerization initiator can be used for the purpose of initiating polymerization or, after image transfer, polymerizing an unpolymerized polymerizable compound. Examples of the thermal polymerization initiator include azo compounds, organic peroxides, inorganic peroxides, and sulfinic acids. Details of these are described in pages 6 to 18 of "Addition Polymerization / Ring-Opening Polymerization" (ed. By Kyoritsu Shuppan, 1983) edited by the Society of Polymer Science and the Editing Committee for Polymer Experiments.

Examples of the photopolymerization initiator include benzophenones, acetophenones, benzoins, thioxanthones and the like. These details are described in “Ultraviolet Curing System” (1989, Sogo Gijutsu Center), pages 63 to 147 and the like. In the light-sensitive material, various surfactants can be used for the purpose of coating aid, improving releasability, improving slipperiness, preventing static charge, accelerating development, and the like. Specific examples of the surfactant are described in JP-A-62-173.
463, 62-183457 and the like.

An antistatic agent can be used in the photosensitive material for the purpose of preventing static charge. As an antistatic agent, it is described in Research Disclosure Magazine, November 1978, No. 17643 (p. 27). In the photosensitive layer of the photosensitive material,
Dyes or pigments may be added for the purpose of preventing halation or irradiation. JP-A-63-29748 discloses a light-sensitive material having a white pigment added to the light-sensitive layer.
There is a description in the publication.

A dye having a property of decoloring by heating or light irradiation may be contained in the microcapsules of the photosensitive material. The dye having the property of decoloring by heating or light irradiation can function as a dye corresponding to a yellow filter in a conventional silver salt photographic system. A photosensitive material using a dye having a property of decoloring upon heating or light irradiation as described above is described in JP-A-63-974940.

When a solvent for a polymerizable compound is used for the light-sensitive material, it is preferable to use it by encapsulating it in a microcapsule different from the microcapsules containing the polymerizable compound.
Incidentally, a photosensitive material using an organic solvent miscible with the polymerizable compound encapsulated in the microcapsule is disclosed in
It is described in JP-A-2-209524.

Various antifoggants or photographic stabilizers can be used in the present invention. For example,
Azoles and azaindenes described in RD17643 (1978), pp. 24-25, JP-A-59-168442.
Carboxylic acids and phosphoric acids containing nitrogen described in JP-A-59-116636, mercapto compounds and metal salts thereof described in JP-A-59-111636, and acetylene compounds described in JP-A-62-87957 are used. .

Various development stoppers can be used in the photosensitive material for the purpose of always obtaining a constant image with respect to the processing temperature and processing time during development. The term "development terminator" as used herein means that after appropriate development, the base is quickly neutralized or reacts with the base to reduce the base concentration in the film, and interact with a compound that stops development or silver and silver salts to suppress development. Compound. Specific examples include an acid precursor that releases an acid when heated, an electrophilic compound that causes a substitution reaction of a coexisting base when heated, or a nitrogen-containing heterocyclic compound, a mercapto compound, and a precursor thereof. For further details, see JP-A-62-253159, pages (31) to (32), and JP-A-1-72419.
No. 79, No. 1-3471, and the like.

In addition to the examples described above, examples of optional components that can be contained in the photosensitive layer and modes of use thereof are also described in the above specification of a series of photosensitive materials, and in Research Disclosure Magazines Vol. 170, 197.
No. 17029, June 2008 (pages 9 to 15). As a layer that can be optionally provided on the photosensitive material,
Examples include an image receiving layer, a heating element layer, an antistatic layer, an anti-curl layer, a peeling layer, a cover sheet or a protective layer, and an antihalation layer (colored layer).

A photosensitive material using a heating element layer is disclosed in JP-A-61-294434, and a photosensitive material provided with a cover sheet or a protective layer is disclosed in JP-A-62-264.
Japanese Patent Application Laid-Open No. 1047/10447 discloses a photosensitive material provided with a colored layer as an antihalation layer.
Nos. 3 and 4, respectively. Further, examples of other auxiliary layers and modes of use thereof are described in the above-mentioned series of photosensitive materials.

In the image forming method using the photosensitive material of the present invention, an image receiving material is generally used together with the photosensitive material. Hereinafter, the image receiving material will be described. The details are described in the above-mentioned “Known Technique No. 5”, pages 149 to 178. The image receiving material may be a support alone, but it is preferable to provide an image receiving layer on the support. The support for the image receiving material is not particularly limited, but is the same as the support for the photosensitive material, such as glass, paper, woodfree paper, baryta paper, coated paper, cast coated paper, synthetic paper, cloth, metal and the like. , Polyester, polyethylene, polypropylene, acetyl cellulose, cellulose ester, polyvinyl acetal,
Examples include films such as polystyrene, polycarbonate, and polyethylene terephthalate, and paper laminated with a resin material or a polymer such as polyethylene.

In the case where a porous material such as paper is used as the support for the image receiving material, a method disclosed in Japanese Patent Application Laid-Open No. 62-20953 is used.
It preferably has a certain degree of smoothness as in the image receiving material described in Japanese Patent Application Laid-Open Publication No. 0-0. An image receiving material using a transparent support is described in JP-A-62-209531. The image receiving layer of the image receiving material is composed of a white pigment, a binder, and other additives, and the white pigment itself or voids between the particles of the white pigment increase the receptivity of the polymerizable compound.

Examples of the white pigment used in the image receiving layer include inorganic white pigments such as oxides such as silicon oxide, titanium oxide, zinc oxide, magnesium oxide, and aluminum oxide, magnesium sulfate, barium sulfate, calcium sulfate, and carbonate. Alkaline earth metal salts such as magnesium, barium carbonate, calcium carbonate, calcium silicate, magnesium hydroxide, magnesium phosphate, magnesium hydrogen phosphate, and others, aluminum silicate, aluminum hydroxide, zinc sulfide, sugar clay, talc , Kaolin, zeolite, acid clay, activated clay, glass and the like. Organic white pigments include polyethylene, polystyrene, benzoguanamine resin, urea-formalin resin,
Melamine-formalin resin, polyamide resin and the like can be mentioned. These white pigments may be used alone or in combination, but those having a high oil absorption to the polymerizable compound are preferred.

As the binder used in the image receiving layer of the present invention, a water-soluble polymer, a polymer latex, a polymer soluble in an organic solvent, and the like can be used. Examples of the water-soluble polymer include carboxymethylcellulose, hydroxyethylcellulose, cellulose derivatives such as methylcellulose, gelatin, phthalated gelatin, casein, proteins such as ovalbumin, dextrin, starches such as etherified starch, polyvinyl alcohol,
Polyvinyl alcohol partial acetal, poly-N-vinyl pyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinyl imidazole, polyvinyl pyrazole, synthetic polymers such as polystyrene sulfonic acid, etc., locust bean gum, pullulan, gum arabic, alginic acid Soda and the like.

Examples of the polymer latex include styrene-butadiene copolymer latex, methyl methacrylate / butadiene copolymer latex, acrylate and / or methacrylate ester polymer or copolymer latex, ethylene / vinyl acetate copolymer Polymer latex and the like can be mentioned. Examples of the polymer soluble in an organic solvent include a polyester resin, a polyurethane resin, a polyvinyl chloride resin, and a polyacrylonitrile resin.

As for the method of using the binder, two or more binders can be used in combination, and further, two binders can be used together in such a ratio as to cause phase separation. An example of such a usage is disclosed in JP-A-1-154789.
There is a description in the official gazette. The average particle size of the white pigment is 0.1.
1 to 20 μm, preferably 0.1 to 10 μm, and the coating amount is 0.1 g to 60 g, preferably 0.5 g to 30 g.
Range. The weight ratio of the white pigment to the binder is preferably in the range of 0.01 to 0.4 binder, and more preferably in the range of 0.03 to 0.3.

The image receiving layer may contain various additives as described below in addition to the binder and the white pigment. For example, when a color developing system including a color former and a developer is used, the image receiving layer can contain a developer. Representative examples of the developer include phenols, organic acids or salts thereof, and esters.When a leuco dye is used as a color image forming substance, a zinc salt of a salicylic acid derivative is preferable. Among them,
Zinc 3,5-di-α-methylbenzylsalicylate is preferred. The color developer is preferably contained in the image receiving layer at a coating amount of 0.1 to 50 g / m ² . More preferably, it is in the range of 0.5 to 20 g / m ² .

The image receiving layer may contain a thermoplastic compound. When a thermoplastic compound is contained in the image receiving layer, the image receiving layer itself is preferably constituted as an aggregate of fine particles of the thermoplastic compound. The image receiving layer having the above configuration has an advantage that a transferred image can be easily formed and a glossy image can be obtained by heating after forming the image.
The thermoplastic compound is not particularly limited, and may be arbitrarily selected from known plastic resins (plastics) and waxes. However, the glass transition point of the thermoplastic resin and the melting point of the wax are preferably 200 ° C. or less. An image receiving material having an image receiving layer containing thermoplastic compound fine particles as described above is disclosed in
It is described in JP-A-2-280071 and JP-A-62-280739.

The image receiving layer may contain a photopolymerization initiator or a thermal polymerization initiator. In image formation using an image receiving material, a color image forming substance is transferred together with an unpolymerized polymerizable compound. For this reason, a photopolymerization initiator or a thermal polymerization initiator can be added to the image receiving layer for the purpose of curing treatment (fixing treatment) of the unpolymerized polymerizable compound. An image receiving material having an image receiving layer containing a photopolymerization initiator is disclosed in JP-A-62-161149, and an image-receiving material having an image receiving layer containing a thermal polymerization initiator is disclosed in JP-A-62-161149.
Each of these is described in Japanese Patent Publication No. 210444.

In the image forming method of the present invention, the photosensitive material is heated from the surface of the support on which the photosensitive layer is not coated, simultaneously with the imagewise exposure, after the imagewise exposure, or after the imagewise exposure. And a series of steps such as a step of superposing the surface of the photosensitive material on which the photosensitive layer is coated and the image receiving material and pressing the same.

As the exposure method in the imagewise exposure step, various exposure means can be used. Generally, a latent image of silver halide is obtained by imagewise exposure to radiation containing visible light. The type of light source and the amount of exposure are determined by the photosensitive wavelength of silver halide (in the case of dye sensitization, the sensitized wavelength)
Alternatively, it can be selected according to the sensitivity.

Typical light sources include natural light, ultraviolet light, visible light, infrared light, fluorescent light, tungsten lamp, mercury lamp, halogen lamp, xenon flash lamp, and laser light sources (gas laser, solid laser, Chemical lasers, semiconductor lasers, etc.), light emitting diodes, plasma arc tubes, FOT and the like. In a special case, a high-energy radiation source such as X-ray, γ-ray, or electron beam can be used.

The light-sensitive material of the present invention, particularly in the case of a full-color light-sensitive material, is composed of microcapsules having photosensitivity in a plurality of spectral regions, so that it is necessary to perform image exposure with a corresponding plurality of spectral lines. It is. Therefore, the above light sources may be used alone or in combination of two or more. When choosing a light source,
It goes without saying that a light source suitable for the photosensitive wavelength of the photosensitive material can be selected, but it can be selected in consideration of whether image information is transmitted via an electric signal, the processing speed of the entire system, compactness, power consumption, and the like.

When the image information does not pass through an electric signal, for example, direct photographing of a landscape or a person, direct copying of an original image,
In the case of exposure through a positive such as a reversal film, an exposure apparatus for printing such as a camera, a printer or an enlarger, and an exposure apparatus for a copying machine can be used. In this case, a two-dimensional image can be simultaneously exposed in one shot, or can be scanned and exposed through a slit or the like. The original image can be enlarged or reduced. In this case, the light source is not a monochromatic light source such as a laser, but a light source such as a tungsten lamp or a fluorescent lamp, or a combination of a plurality of monochromatic light sources.

When image information is recorded via an electric signal, a light emitting diode and various lasers may be used in combination according to the color sensitivity of the heat-developable color photosensitive material as an image exposure apparatus. Various devices known as an image display device (CRT, liquid crystal display, electroluminescence display, electrochromic display, plasma display, etc.) can also be used. In this case, the image information is an image signal obtained from a video camera or an electronic still camera, a television signal represented by the Nippon Television Signal Standard (NTSC),
An image signal obtained by dividing an original image into a large number of pixels by a scanner or the like, and an image signal stored in a recording material such as a magnetic tape or a disk can be used.

When exposing a color image, LEDs, lasers, fluorescent tubes, and the like are used in combination in accordance with the color sensitivity of the light-sensitive material, but the same one may be used in combination, or a combination of different kinds may be used. You may. The color sensitivity of the photosensitive material is R (red), G (green), B (blue) in the field of photography.
Although the photosensitivity is normal, in recent years, it is often used in combination of UV, IR, and the like, and the use range of the light source is expanding. For example, the color sensitivity of the photosensitive material is (G, R, IR)
Or (R, IR (short wave), IR (long wave)),
(UV (short wave), UV (medium wave), UV (long wave)), (U
V, B, G). The light source may be another type such as a combination of two LEDs and a laser. The light emitting tube or element may be subjected to scanning exposure using a single tube or element for each color, or an array of elements may be used to increase the exposure speed. Available arrays include LED arrays, liquid crystal shutter arrays, magneto-optical element shutter arrays, and the like.

As the image display device described above, a CRT
There is a color display and a monochrome display as described above, but a method of performing exposure several times by combining a monochrome display with a color filter may be adopted. Existing 2
The two-dimensional image display device may be used in a one-dimensional manner like FOT, or may be used by dividing one screen into several parts and combining them with scanning.

By the above imagewise exposing step, a latent image is obtained on the silver halide contained in the microcapsules. The image forming method of the present invention includes a step of heating the photosensitive material simultaneously with or after the imagewise exposure in order to thermally develop the photosensitive material. Preferably, thermal development is performed by heating from the surface of the support on which the photosensitive layer of the photosensitive material is not coated.

The heating means is disclosed in JP-A-61-29
As in the light-sensitive material described in Japanese Patent No. 4434, a heating element layer may be provided on the surface of the support on which the light-sensitive layer of the light-sensitive material is not coated, and heating may be performed. Further, as described in JP-A-61-147244, a hot plate, an iron, and a heat roller are used, or as described in JP-A-62-144166, a photosensitive material is sandwiched between a heat roller and a belt. A heating method may be used.

That is, the photosensitive material may be brought into contact with a heating element having a surface area larger than the area of the photosensitive material to heat the entire surface simultaneously, or a heating element having a smaller surface area (heating plate,
(A heat roller, a heat drum, etc.), and the entire surface may be heated over time by scanning it.
In addition to the heating method in which the heating element is brought into direct contact with the photosensitive material as described above, the photosensitive material can be heated in a non-contact state by applying electromagnetic waves, infrared rays, hot air or the like to the photosensitive material.

In the image forming method of the present invention, heat development is performed by heating the photosensitive material from the surface of the support on which the photosensitive layer is not coated. The side with the mark may be in direct contact with the air,
In order to keep heat so as not to escape heat, it may be covered with a heat insulating material or the like. In this case, it is preferable not to apply a strong pressure (10 kg / cm ² or more) to the photosensitive layer so as not to break the microcapsules contained in the photosensitive layer.

The heat development by heating is carried out at the same time as or after the imagewise exposure, but it is preferred that the heating is carried out 0.1 seconds or more after the imagewise exposure. The heating temperature is generally
60 ° C. to 250 ° C., preferably 80 ° C. to 180 ° C., and the heating time is between 0.1 second to 10 seconds, preferably 0.1 second
It is between seconds and 5 seconds.

The photosensitive material is subjected to thermal development as described above to polymerize the polymerizable compound in the portion where the silver halide latent image is formed or in the portion where the silver halide latent image is not formed. In the case where a polymerization inhibitor is formed by a reaction with a reducing agent in a portion where a silver halide latent image is formed, heat or photopolymerization starting in a photosensitive layer, preferably added in a microcapsule in advance. The agent can be decomposed by heating or irradiating light to uniformly generate radicals and polymerize the polymerizable compound in the portion where the latent image of silver halide is not formed. In this case, in addition to the imagewise exposure step and the heat development step described above, a step of heating or exposing the entire surface is required if necessary. The method is the same as the imagewise exposure step or the heat development step.

In the image forming method of the present invention, the unpolymerized polymerizable compound is transferred to the image receiving material by a step of pressing the photosensitive material having a polymer image formed on the photosensitive layer and the image receiving material in a superposed state, A color image can be obtained on the image receiving material. As the above-mentioned pressurizing method, a conventionally known method can be used.

For example, the photosensitive material and the image receiving material may be sandwiched between press plates such as a presser, or may be pressed while being conveyed using a pressure roller such as a nip roll. The pressure may be intermittently applied by a dot impact device or the like.
Further, air pressurized to a high pressure can be blown by an air gun or the like, or pressurized by an ultrasonic generator, a piezoelectric element, or the like. The pressure required for pressurization is 500 kg / cm ² or more,
Preferably, it is 800 kg / cm ² or more. However, when heating is combined with 40 ° to 120 ° C. during pressurization, 500 kg / cm
It may be ² or less.

The light-sensitive material of the present invention has many uses such as a light-sensitive material for color photographing and printing, a light-sensitive material for printing, a light-sensitive material for computer graphic hard copy, and a light-sensitive material for copiers. It is possible to create a compact and inexpensive image forming system such as a copying machine, a printer, and a simple printing machine.

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EXAMPLES Example 1 Preparation of Silver Halide Emulsion (EB-1) (Invention) 24 g of lime-treated inert gelatin was added to distilled water.
After dissolution at 0 ° C for 1 hour, KBrlg was added, and 1
The pH was adjusted to 3.2 by adding N sulfuric acid. Add (AG
After adding 10 mg of S-1), Solution I and Solution II were added to 7
It was added simultaneously at 5 ° C. over 15 minutes. Further, III
Solution and IV solution were added simultaneously at 75 ° C. over 15 minutes. After the addition was completed, the pH was adjusted to 6.0 with 1N NaOH, and the PAg was adjusted to 9.4 by adding KBr.
Add 1.9 mg and 2.3 mg of (AZ-4) and add 75
Aged at 60 ° C for 60 minutes. After aging, 480 mg of (SB-1) was added and aging was performed for 20 minutes, and then 200 g of an aqueous solution containing 4.1 g of KI was added at an equal flow rate over 5 minutes after the addition. To this emulsion, 1.1 g of (CK-1) was added, sedimented, washed with water so as to obtain the target electric conductivity, desalted, dissolved in 6 g of lime-processed gelatin, and further dissolved in (ATR-
0.8% of a 3.5% aqueous solution of 3) and (ATR-
1.5 cc of a 72% solution of 1) and KBr were added to adjust the pH to 6.2 and pAg 8.5. Average particle size 0.
550 g of a monodispersed silver iodobromide emulsion (EB-1) having a particle diameter of 35 μm, a coefficient of variation of 15%, and an electric conductivity of 4 mScm ⁻¹ was prepared. (CK-1) Polyisobutylene-monosodium combaleate (AZ-4) Sodium thiosulfate pentahydrate

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Preparation of Silver Halide Emulsion (EB-2) (Invention) As in the case of silver halide emulsion (EB-1), except that (S
B-1) KI over 5 minutes before adding 480 mg.
200 g of an aqueous solution containing 1 g was added at an equal flow rate, and then 480 mg of (SB-1) was added. The mixture was aged for 20 minutes, and then settled, desalted, and washed with water.

Preparation of Silver Halide Emulsion (EB-3) (Comparative Example) As in the case of silver halide emulsion (EB-1), (A)
(SB-1) without adding (AZ-1) and (AZ-4).
-1) After adding 480 mg and aging for 20 minutes, 200 g of an aqueous solution containing 4.1 g of KI was further added at an equal flow rate over 5 minutes after the addition.

Preparation of silver halide emulsion (EB-4) (Comparative Example) A silver halide emulsion (EB-
In 3), 1.9 mg of (AZ-1) and 2.3 of (AZ-4) were added.
mg was added and the mixture was aged at 75 ° C. for 60 minutes.

Preparation of Silver Halide Emulsion (EB-5) (Comparative Example) Silver halide emulsion (EB-5) which had been settled, desalted and washed with water
19 mg of (AZ-1) and 23 mg of (AZ-4) were added to 3), and the mixture was aged at 75 ° C for 60 minutes.

Preparation of Silver Halide Emulsion (EB-6) (Invention) As in the case of silver halide emulsion (EB-1), except that the finished emulsion was washed with water so as to have an electric conductivity of 8 mScm ^-1. Salting was performed to prepare a silver halide emulsion (EB-6).

Preparation of Silver Halide Emulsion (EB-7) (Invention) As in the case of silver halide emulsion (EB-1), except that the finished emulsion was washed with water so as to have an electric conductivity of 7 mScm ^-1 and dewatered. Salting was performed to prepare a silver halide emulsion (EB-7).

Preparation of Silver Halide Emulsion (EB-8) (Invention) As in the case of silver halide emulsion (EB-1), except that the finished emulsion was washed with water so as to have an electric conductivity of 6 mScm ^-1. Salting was performed to prepare a silver halide emulsion (EB-8).

Preparation of Silver Halide Emulsion (EB-9) (Invention) As in the case of silver halide emulsion (EB-1), except that the finished emulsion was washed with water so as to have an electric conductivity of 5 mScm ^-1 and dewatered. Salting was performed to prepare a silver halide emulsion (EB-9).

Preparation of Silver Halide Emulsion (EB-10) (Invention) As in the case of silver halide emulsion (EB-1), except that the finished emulsion was washed with water so as to have an electric conductivity of 2 mScm ^-1. Salting was performed to prepare a silver halide emulsion (EB-10).

Preparation of Silver Halide Emulsion (EB-11-20) (Invention) As in the case of silver halide emulsion (EB-1), (A)
Before adding Z-1) and (AZ-4), the following compounds (AA-1) to (AA-10) are added as shown in Table 1, and (AZ-1) and (AZ- The amount of (4) was changed as shown in Table 1 to obtain a silver halide emulsion (EB-11).
-20) were prepared.

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[Table 1]

Preparation of solid dispersion (KB-1) 5.4 of lime-processed gelatin in a 300 ml dispersion container
110 g of a 5% aqueous solution of polyethylene glycol (average molecular weight: 2,000), 70 g of a base precursor (BG-1) and 200 ml of glass beads having a diameter of 0.5 to 0.75 mm were added thereto.
Disperse at 0 rpm for 30 minutes, adjust the pH to 6.5 with 2N sulfuric acid, and adjust the base precursor (BG
-1) solid dispersion (KB-1) was obtained.

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Preparation of Pigment Dispersion (GY-1) 45 g of Chromofine Yellow 5900 (trade name, manufactured by Dainichi Seika Co., Ltd.) was mixed with 255 g of the polymerizable compound (MN-1), and the mixture was mixed with an Eiger motor mill (Eiger. The mixture was stirred at 5,000 rpm for 1 hour using an engineer (manufactured by Engineering Co., Ltd.) to obtain a dispersion (GY-1). Polymerizable compound (MN-1) Compound described in Synthesis Example 1 of JP-A-64-68339 (manufactured by Nippon Kayaku Co., Ltd.)

Preparation of Photosensitive Composition (PB-1) To 45 g of the pigment dispersion (GY-1) was added (SV) of (1P-1).
-1) 9 g of a 10% (wt%) solution, (RD-1) 2.
3g, (RD-3) 3.1g, (FF-3) (SV-
1) 2 g of a 0.5% (wt%) solution and (ST-1)
0.5 g was added and dissolved to prepare an oily solution. To this solution, 7.6 g of a silver halide emulsion (EB-1) and 24 g of a solid dispersion (KB-1) were added, and the mixture was stirred at 10,000 rpm for 5 minutes using a 40φ dissolver while keeping the temperature at 60 ° C. Thus, a W / O emulsion photosensitive composition (PB-1) was obtained.

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The photosensitive microcapsule dispersion (CB-
Preparation of 1) 46 g of water was added to 4 g of a 15% aqueous solution of the polymer (2P-4).
In addition, the mixed solution was adjusted to pH 5.0 with 2N sulfuric acid. To this solution, 50 g of a 10% aqueous solution of the polymer (2P-2) was added and mixed at 60 ° C. for 30 minutes. This mixture was added to the photosensitive composition (PB-1), and the mixture was stirred at 6000 rpm for 20 minutes at 60 ° C. using a 40φ dissolver.
An emulsion in the form of an O / W emulsion was obtained. Separately, 31.5 g of melamine was mixed with 5% aqueous solution of formaldehyde 37%.
2.2 g and 170.3 g of water were added, and the mixture was heated to 60 ° C. and stirred for 30 minutes to obtain a transparent aqueous solution of a melamine-formaldehyde precondensate.

25 g of this precondensate is added to the emulsion in the form of the W / O / W emulsion cooled to 40 ° C.
The pH was adjusted to 5.0 using 2N sulfuric acid while stirring at 1200 rpm with a propeller blade. Next, this liquid was heated to 70 ° C. in 30 minutes, and stirred for 30 minutes. Add 10.3g of 40% aqueous solution of urea to this and add 2N sulfuric acid
The pH was adjusted to 3.5 and stirring at 70 ° C. was continued for a further 40 minutes. After cooling this solution to 40 ° C, κ─ carrageenan 3
9% aqueous solution was added, the mixture was stirred for 10 minutes, and the pH was adjusted to 6.5 using a 2N aqueous sodium hydroxide solution to prepare a photosensitive microcapsule dispersion liquid (CB-1).

Preparation of High Boiling Point Organic Compound Dispersion (HB-1) MN-1 was added to 15 g of a 5% aqueous solution of sodium dodecylbenzenesulfonate in 50 g of a 10% aqueous solution of polymer (PC-3) kept at 60 ° C. 50 g was added, and the mixture was dispersed with a homogenizer (manufactured by Nippon Seiki) at 8000 rpm for 10 minutes. Polymer (PC-3) PVAKL318 (Kuraray's carboxy-modified PVA)

Preparation of High Boiling Point Organic Compound Capsule (HC-1) To 45 g of (MN-1) as a high boiling point organic compound, (1P
9 g of a (SV-1) 10% (wt%) solution of
(RD-1) 1.6 g, (RD-2) 1.2 g, (FF
2 g of (SV-1) 0.5% (wt%) solution of -3) was added and dissolved to prepare an oily solution (YU-1). 36 g of water was added to 4 g of a 15% aqueous solution of the polymer (2P-4), and the mixed solution was adjusted to pH 5.0 with 2N sulfuric acid. To this solution, 60 g of a 10% aqueous solution of the polymer (2P-2) was added and mixed at 60 ° C. for 30 minutes. This mixture was added to the oily solution composition (YU-1) and stirred at 6000 rpm for 20 minutes at 60 ° C. using a 40φ dissolver to obtain an emulsion in an emulsion state. Polymer (2P-4) Potassium polyvinylbenzenesulfinate-co-acrylamide Polymer (2P-2) Polyvinylpyrrolidone K-9
Next, in the preparation of the photosensitive microcapsule dispersion (CB-1), a high boiling organic compound was prepared in the same manner except that the oily solution composition (YU-1) was used instead of the photosensitive composition (PB-1). A compound capsule dispersion (HC-1) was prepared.

A photosensitive microcapsule dispersion (CB-2)
To 20) Preparation of photosensitive microcapsules in the same manner as photosensitive microcapsule dispersion liquid (CB-1), except that silver halide emulsion (EB-2 to 20) is used instead of silver halide emulsion (EB-1). Dispersions (CB-2 to 20) were prepared. The sample numbers of the photosensitive microcapsule dispersions (CB-2 to 20) correspond to the corresponding silver halide emulsions (EB-2 to EB-2).
0).

Preparation of Photosensitive Material 101 45 g of the photosensitive microcapsules (CB-1) were taken out, heated at 40 ° C. without stirring, dissolved and mixed, and mixed with the surfactant (WW-1). 6.5 g of 1% aqueous solution, 8 g of 1% aqueous solution of surfactant (WW-2), (HB-1)
7.5 g of dispersion and 7.5 g of (HC-1) dispersion
And 15 cc of water were added and stirred at 40 ° C. for 10 minutes to mix. This solution was filtered with a 44 μm mesh filter cloth to prepare a capsule coating solution 101.

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This coating solution was applied on a 12 μm-thick polyethylene terephthalate film on an aluminum-deposited surface of a support having aluminum deposited thereon by an extrusion method so as to have a coating amount of 100 cc / m ² and dried at 60 ° C. The photosensitive material 101 was prepared by winding the film under the conditions of 25 ° C. and 65% so that the coated surface was on the inside.

Preparation of photosensitive materials 102 to 120 As in the case of the photosensitive material 101, the photosensitive microcapsules (C-1) were used instead of the photosensitive microcapsules (CB-1).
B-2 to 20), a light-sensitive material 101 is prepared.
Coating, drying and wrapping were carried out in the same manner as in the above to prepare photosensitive materials 102 to 120. The last two digits of the number of the photosensitive material correspond to the number of the photosensitive microcapsule used therefor.

Preparation of Image Receiving Material (RS-1) Calcium carbonate (PC700, manufactured by Shiraishi Industry Co., Ltd.) 24
0 g, surfactant (Poise 520, manufactured by Kao Corporation) 5.
After stirring and mixing 6 g and 354.4 ml of water, a dispersing machine (trade name: Ultra Disperser (LK-41)
(Type), manufactured by Yamato Scientific Co., Ltd.) at 8000 rpm for 3 minutes. 52 g of this dispersion and an aqueous solution 4 of 10% polyvinyl alcohol (PVA-117, manufactured by Kuraray Co., Ltd.)
0 g, and further 1% of surfactant (WW-3)
4 ml of an aqueous solution and 22 ml of water were added to prepare a coating solution for forming an image receiving layer.

This coating liquid was weighed to 80 g / m ^{2 on} a paper support (fiber length distribution defined by JIS-P-8207, and the sum of the weight% of the remaining 24 mesh and the weight% of the remaining 42 mesh was 30). Paper support using a base paper having a fiber length distribution of about 60% to 60% [JP-A-63-18623].
No. 9]), and then uniformly applied to a thickness of 65 g / m ² , followed by drying at 60 ° C. to prepare an image receiving material (RS-1).

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Image formation Processing condition A: 5000 lux using a halogen lamp adjusted to a color temperature of 3100 ° K and passing through a wedge whose transmission density is continuously changed from 0 to 4.0 in a black silver image and density is 0 to 4.0.
Exposure was performed under an exposure condition of 1 second. Immediately after the exposure, the opposite side of the surface coated with the light-sensitive material was brought into close contact with a drum heated to 150 ° C. and heat-developed for 1.0 second. After 8 seconds, the image receiving material (RS-1) and the coated surfaces are superimposed on each other to be 3.2 cm.
/ Cm ² at a speed of 3 cm in diameter and 200 kg / cm ² (surface temperature
70 ° C.), and the image receiving material was peeled off from the photosensitive material immediately after passing through the pressure roller. Sensitivity (Minimum image density + 0.2 is necessary to obtain the density than the transferred image receiving paper material.
The smaller the number, the higher the sensitivity of the photosensitive material. ),and,
The maximum image density (the higher the density, the better the discrimination) was measured. The results are shown in Table 2.

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[Table 2]

Light-sensitive materials 101 to 102 and 106 of the present invention
It can be seen that the samples No. to No. 120 have high sensitivity and good discrimination. In particular, regarding the minimum image density, of the photosensitive material of the present invention, the conductivity of the completed emulsion is 6 mScm.
Photosensitive material 101 to 102, 108 of the present invention which is not more than ^-1
~ 120 indicates good performance. Example 2

Preparation of Silver Halide Emulsion (EG-1) (Invention) 24 g of lime-processed inert gelatin was added to distilled water.
After dissolution at 0 ° C for 1 hour, KBrlg was added, and 1
The pH was adjusted to 3.2 by adding N sulfuric acid.

After adding 10 mg of (AGS-1) to this solution, Solution I and Solution II were added simultaneously at 75 ° C. over 15 minutes. After the addition was completed, the pH was adjusted to 6.0 with 1N NaOH, and the pAg was adjusted to 9.4 by adding KBr.
2.5 mg and (AZ-4) 3.3 mg were added, and the mixture was aged at 75 ° C. for 60 minutes. After aging, 480 mg of (SG-1) was added, and the temperature was raised to 35 ° C. 20 minutes after the addition, and 200 g of an aqueous solution containing 4.1 g of KI was added at a constant flow rate over 5 minutes.

To this emulsion, 1.1 g of (CK-1) was added, sedimented, washed with water so as to obtain a target electric conductivity, desalted, dissolved in 6 g of lime-treated gelatin, and further dissolved in (ATR).
-3) 0.8 cc of 3.5% aqueous solution, (ATR-1) 7
1.5 cc of 2% solution and KBr were added to adjust the pH to 6.2, pAg.
Was adjusted to 8.5. 550 g of a monodispersed silver iodobromide emulsion (EG-1) having an average grain size of 0.20 μm, a coefficient of variation of 19%, and an electric conductivity of 4 mScm ⁻¹ was prepared.

Solution I AgNO ₃ 80 g distilled water 600 cc Solution II KBr 72.8 g distilled water 600 cc

Preparation of Silver Halide Emulsion (EG-2) (Comparative Example) As in the case of silver halide emulsion (EG-1), (A)
(SG-1) and (AZ-4) without adding (SG
-1) After adding 480 mg and aging for 20 minutes, 200 g of an aqueous solution containing 4.1 g of KI was further added at an equal flow rate over 5 minutes after the addition.

Preparation of a silver halide emulsion (EG-3) (Comparative Example) A silver halide emulsion (EG-
2.5 mg of (AZ-1) and 3.3 of (AZ-4)
mg was added and the mixture was aged at 75 ° C. for 60 minutes.

Preparation of Silver Halide Emulsion (EG-4) (Invention) As in the case of silver halide emulsion (EG-1), except that the finished emulsion is washed with water so as to have an electric conductivity of 7 mScm ^-1 and halogenated. A silver halide emulsion (EG-4) was prepared.

Preparation of silver halide emulsion (ER-1) (this invention) 24 g of deionized gelatin was added to distilled water, and
After dissolution over a period of time, KBrlg was added, and the pH was adjusted to 3.2 by adding 1N sulfuric acid. After 10 mg of (AGS-1) was added to this solution, Solution I and Solution II were added simultaneously at 75 ° C. over 15 minutes. After the addition is completed, the pH is adjusted to 1N NaOH.
The pAg was adjusted to 9.4 by addition of KBr to 6.0, and 5.0 mg of (AZ-1) and 6.5 mg of (AZ-4).
And aged at 75 ° C. for 60 minutes. After aging (SR-1)
120 mg, (SR-6) 120 mg, and (SR-2)
300 mg was added, the temperature was raised to 35 ° C. 20 minutes after the addition, and an aqueous solution 200 containing 4.1 g of KI was taken over 5 minutes.
g was added at an equal flow rate.

To this emulsion, 1.1 g of (CK-1) was added, sedimented, washed with water so as to attain the target electric conductivity, desalted, dissolved in 6 g of lime-treated gelatin, and further dissolved in (ATR).
-3) 0.8 cc of 3.5% aqueous solution, (ATR-1) 7
1.5 cc of 2% solution and KBr were added to adjust the pH to 6.2, pAg.
Was adjusted to 8.5. Monodispersed silver iodobromide emulsion (ER-1) 550 having an average grain size of 0.21 μm and a variation coefficient of 20%
g was prepared.

Solution I AgNO ₃ 80 g Distilled water 600 cc Solution II KBr 72.8 g Distilled water 600 cc

Preparation of Silver Halide Emulsion (ER-2) (Comparative Example) As in the case of silver halide emulsion (ER-1), except that (A
Z-1) and (AZ-4) without adding (SR
-1) 120 mg, (SR-6) 120 mg, and (SR
-2) After adding 300 mg and aging for 20 minutes, 200 g of an aqueous solution containing 4.1 g of KI was further added at an equal flow rate over 5 minutes after the addition.

Preparation of Silver Halide Emulsion (ER-3) (Comparative Example) A silver halide emulsion (ER-E) which has been settled, desalted and washed with water.
In 2), 5.0 mg of (AZ-1) and 6.5 of (AZ-4) were added.
mg was added and the mixture was aged at 75 ° C. for 60 minutes.

Preparation of Silver Halide Emulsion (ER-4) (Invention) As in the case of silver halide emulsion (ER-1), except that the finished emulsion is washed with water so as to have an electric conductivity of 7 mScm ^-1. A silver halide emulsion (ER-4) was prepared.

[0120]

Embedded image

Preparation of Pigment Dispersion (GM-1) Rubin F6B was added to 270 g of the polymerizable compound (MN-1).
30 g (trade name, manufactured by Hoechst) was mixed, and the mixture was stirred at 5,000 rpm for 1 hour using an Eiger motor mill (manufactured by Eiger Engineering) for 1 hour to obtain a dispersion (GM-
1) was obtained.

Preparation of Pigment Dispersion (GC-1) To 255 g of the polymerizable compound (MN-1), 45 g of copper phthalocyanine (CI Pigment 15), and Solsperse 500
0 (manufactured by ICI) 1.13 g, Solsperse 24000
3.37 g (manufactured by ICI) was mixed and stirred at 5,000 rpm for 1 hour using an Eiger motor mill (manufactured by Eiger Engineering) to obtain a dispersion (GC-1).

Preparation of Photosensitive Composition (PG-1) To 45 g of the pigment dispersion (GM-1) was added the (SV) of (1P-1).
-1) 9 g of a 10% (wt%) solution, (RD-1) 2.
3g, (RD-3) 3.1g, (FF-3) (SV-
1) 2 g of a 0.5% (wt%) solution and (ST-1)
0.5 g was added and dissolved to prepare an oily solution. To this solution, 7.6 g of a silver halide emulsion (EG-1) and 24 g of a solid dispersion (KB-1) were added, and the mixture was stirred at 10,000 rpm for 5 minutes using a 40φ dissolver while keeping the temperature at 60 ° C. , W / O emulsion photosensitive composition (P
G-1) was obtained.

Preparation of Photosensitive Composition (PR-1) To 45 g of the pigment dispersion (GC-1) was added (S) of (1P-4).
V-1) 9 g of a 10% (wt%) solution, (RD-1)
2.3 g, (RD-2) 3.1 g, (FF-3) (S
V-1) 2 g of a 0.5% (wt%) solution and (ST-
1) 0.5 g was added and dissolved to prepare an oily solution.

To this solution was added a silver halide emulsion (ER-1).
7.6 g and 24 g of the solid dispersion (KB-1) were added, and 5
While maintaining the temperature at 0 ° C., the mixture was stirred at 10,000 rpm for 5 minutes using a 40φ dissolver to obtain a W / O emulsion photosensitive composition (PR-1).

The photosensitive microcapsule dispersion (CG-
Preparation of 1) 36 g of water was added to 4 g of a 15% aqueous solution of the polymer (2P-4).
In addition, the mixed solution was adjusted to pH 5.0 with 2N sulfuric acid. To this solution, 60 g of a 10% aqueous solution of the polymer (2P-2) was added and mixed at 60 ° C. for 30 minutes. This mixture was added to the photosensitive composition (PG-1), and the mixture was stirred at 6000 rpm for 20 minutes at 60 ° C. using a 40φ dissolver, and the W / W
An emulsion in the form of an O / W emulsion was obtained. Polymer (2P-4) Potassium polyvinylbenzenesulfinate-co-acrylamide

4 g of a 15% aqueous solution of the polymer (2P-4)
Was added to the mixture, and the mixture was adjusted to pH 5.0 with 2N sulfuric acid. To this solution, 50 g of a 10% aqueous solution of the polymer (2P-2) was added and mixed at 60 ° C. for 30 minutes. The photosensitive composition (PR-1) was added to the mixture, and the mixture was stirred at 6000 rpm for 20 minutes at 60 ° C. using a 40φ dissolver to obtain an emulsion in an emulsion state. Separately, 31.5 g of melamine was mixed with 5% aqueous solution of formaldehyde 37%.
2.2 g and 170.3 g of water were added, and the mixture was heated to 60 ° C. and stirred for 30 minutes to obtain a transparent aqueous solution of a melamine-formaldehyde precondensate.

25 g of this precondensate was added to the emulsion in the above-mentioned emulsion cooled to 40 ° C., and the pH was adjusted with 2N sulfuric acid while stirring at 1200 rpm with a propeller blade.
It was adjusted to 5.0. Then, the solution was heated to 70 ° C. for 30 minutes.
And the mixture was further stirred for 30 minutes. To this, 10.3 g of a 40% aqueous urea solution was added, and the pH was adjusted to 3 with 2N sulfuric acid.
5, and stirring at 70 ° C. was continued for another 40 minutes.
After cooling this solution to 40 ° C., 9 g of a 3% aqueous solution of K-carrageenan was added, and the mixture was stirred for 10 minutes, adjusted to pH 6.5 with a 2N aqueous sodium hydroxide solution, and dispersed in a photosensitive capsule dispersion liquid (CG-1). ) Was prepared.

Next, in the preparation of (CB-1) in Example 1, except that (PR-1) was used instead of (PB-1), the photosensitive microcapsule dispersion liquid (CR-
1) was prepared.

A photosensitive microcapsule dispersion (CG-2)
Preparation of the photosensitive microcapsules in the same manner as the photosensitive microcapsule dispersion liquid (CG-1) except that the silver halide emulsion (EG-2 to 4) is used instead of the silver halide emulsion (EG-1). Dispersions (CG-2 to CG-4) were prepared. The sample numbers of the photosensitive microcapsule dispersions (CG-2 to CG-4) corresponded to the corresponding silver halide emulsions (EG-2 to EG-4).

A photosensitive microcapsule dispersion (CR-2)
Preparation of photosensitive microcapsules in the same manner as in photosensitive microcapsule dispersion liquid (CR-1) except that silver halide emulsion (ER-2 to 4) is used instead of silver halide emulsion (ER-1) Dispersions (CR-2 to 4) were prepared. The sample numbers of the photosensitive microcapsule dispersions (CR-2 to CR-4) corresponded to the corresponding silver halide emulsions (ER-2 to ER-3).

Preparation of Photosensitive Material 201 15 g of photosensitive microcapsules (CB-1) and (CG
-1) and 15 g of (CR-1) were separately taken out, heated to 40 ° C. without stirring, dissolved and mixed, and a 5% aqueous solution of a surfactant (WW-1) 6. 5
g, 1 g of a 1% aqueous solution of a surfactant (WW-2), (HB
-1) 7.5 g of the dispersion and 7.5 g of the (HC-1) dispersion and 15 cc of water were added, and the mixture was stirred at 40 ° C. for 10 minutes and mixed. This solution was filtered through a 44 μm mesh filter cloth to prepare a capsule coating solution 201.

This coating solution was applied on an aluminum-deposited surface of a support obtained by evaporating aluminum on a 12 μm-thick polyethylene terephthalate film by an extrusion method so as to have a coating amount of 100 cc / m ^2, and dried at 60 ° C. The film was rolled up at 25 ° C. and 65% so that the coated surface was on the inside, and a photosensitive material 201 was prepared.

Preparation of photosensitive materials 202 to 204 In the same manner as in photosensitive material 201, photosensitive microcapsules shown in Table 3 were used instead of photosensitive microcapsules (CB-1), (CG-1) and (CR-1). A coating solution was prepared, and coated, dried, and rolled in the same manner as the photosensitive material 201 to prepare photosensitive materials 202 to 204. In addition,
(CB-3), (CB-4) and (CB-8) are examples of the first embodiment.
What was prepared by was used.

[0135]

[Table 3]

Image formation Processing condition B: 5000 lux using a halogen lamp adjusted to a color temperature of 3100 ° K and passing through a wedge whose transmission density is continuously changed from 0 to 4.0 in a black silver image.
Exposure was performed under an exposure condition of 1 second. Immediately after the exposure, the opposite side of the surface coated with the light-sensitive material was brought into close contact with a drum heated to 150 ° C. and heat-developed for 1.0 second. After 2 seconds, the image receiving material (RS-1) and the coated surfaces are overlapped with each other to be 3.2 cm.
/ Cm ² at a speed of 3 cm in diameter and 200 kg / cm ² (surface temperature
70 ° C.), and the image receiving material was peeled off from the photosensitive material immediately after passing through the pressure roller.

[0137]

[Table 4]

The sensitivity and maximum image density of each color were measured in the same manner as in Example 1. The results are shown in Table 3. The photosensitive material 201 of the present invention is superior to Comparative Examples 202 to 204 in both sensitivity and discrimination.

Claims (4)

(57) [Claims] 1. A silver halide emulsion containing silver halide grains including a layer having a high silver iodide content on the surface of the grains,
A photothermographic material comprising at least one silver halide emulsion which has been chemically sensitized before desalting and adding iodine ions. 2. The photothermographic material according to claim 1, wherein the silver halide emulsion has a sensitizing dye added before desalting. 3. A silver halide emulsion having an electric conductivity of 6 after desalting.
3. The photothermographic material according to claim 1, wherein the photothermographic material has a mScm ^-1 or less. 4. A light-sensitive material comprising a support having thereon a photosensitive layer containing photosensitive microcapsules containing at least silver halide, a reducing agent, a polymerizable compound, and a color image-forming substance on the support. A photothermographic material comprising at least one silver halide emulsion of 2 or 3.