JP2001022029A - Heat-developable image recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the heat-developable image recording material prevented from occurrence of coating trouble at the time of forming an image forming layer or the like and occurrence of pinholes and uneven development at the time of heat-development. SOLUTION: This heat-developable image recording material is provided on at least one side of a support with an image forming layer in which heat development processing is executed at a developing temperature of 80 deg.C to 140 deg.C, and an aqueous coating fluid for the image forming layer comprising a latex and image forming additives is prepared by filtering at least >=50 weight % of the dry solid fraction of the total additives through a filter having ports sized each to 2 to 30 μm, and then adding them to the latex, and the image forming layer is formed by applying this aqueous coating fluid and drying it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable image recording material and a method for producing the same, and more particularly to a heat-developable image recording material having no coated surface defects useful for scanners, imagesetters and the like, and a method for producing the same. . The heat-developable image recording material of the present invention can be used as a heat-developable black-and-white image recording material, a microdevelopment material for heat development, and a radiographic material for heat development, which are excellent in production suitability.

[0002]

2. Description of the Related Art One of the methods for exposing a photographic light-sensitive material is to scan an original figure and to expose a silver halide photographic light-sensitive material based on an image signal of the original figure, thereby obtaining a negative image or a positive image corresponding to the image of the original figure. An image forming method based on a so-called scanner method for forming an image is known. Further, there is a demand for a scanner photosensitive material having a super-high contrast characteristic for a case of printing on a printing plate directly after the output from a scanner to a film, without going through a turning process, or a scanner light source having a soft beam profile. A photosensitive material having a photosensitive layer on a support and performing image formation by exposing the image,
Many are known. Among them, a technology for forming an image by thermal development is a system that can simplify environmental protection and image forming means. In recent years, in the field of photoengraving, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental conservation and space saving. Therefore, there is a need for a technique relating to a photosensitive heat-developable material for photolithography, which can be efficiently exposed by a laser scanner or a laser imagesetter and can form a sharp black image having high resolution and sharpness. It has been. These photosensitive heat-developable materials eliminate the use of solution-based processing chemicals and can provide customers with a simpler heat-development system that does not damage the environment.

A method for forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,457,075 and D.C. Morgan and B.A. Shelly
y) "Heat treated silver system (Thermall
y Processed Silver Systems) ”(Imaging
Processings and Materials (Imaging Proc
esses and Materials) Neblette Eighth Edition, Stage
rge), V. Walworth, A .; Shep (Sh
epp) compilation, page 2, 1969). Such photosensitive materials are prepared by dispersing a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in. The photosensitive material is stable at normal temperature, but when heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate. This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. These techniques are applied not only to the graphic arts field, but also to black-and-white photosensitive materials, micro-sensitive materials, and X-ray photosensitive materials, and are also being applied to color photosensitive materials. And, it is being developed as a heat development system which does not require any aqueous processing solution.

At this time, a water-dispersible polymer, particularly a latex, which is preferably used as a binder for the heat-developable photosensitive material, is useful, and is suitable for the design of a photosensitive material which is less polluting than an organic solvent. You.
However, in contrast to the gelatin systems that have been used in conventional aqueous systems, these coating solutions have latex itself as dispersed particles, and various coexisting photographic additives are also dispersed particles,
It contains coarse particles that are insufficiently dispersed in advance, or is formed by agglomeration and precipitation in a coating solution, so that there is a problem that image defects occur after coating. Further, as a more serious problem, precipitated latex or dispersed particles may cause clogging in a pipe, agglomeration by a liquid feed pump, or production problems such as generation of a coating streak due to adhesion to the tip of a coating gasser portion. Sometimes. Particularly in the case of a latex binder, foreign matter of latex or additive dispersed particles is
During the drying process after coating, unevenness of drying occurs mainly on foreign substances, and crack-like defects and the like are generated. For example, a 100 μm pinhole is a problem in the case of graphic arts for commercial printing, and a pinhole of several microns is a serious problem in the case of micro-photosensitive materials that are used in an enlarged manner. Become. In addition, when a latex binder is used, there is a big problem that bubbles existing in a coating solution cause film cracking during drying after coating, which was not possible when a gelatin binder was used.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art. That is, an object of the present invention is to provide a heat-developable image recording material which does not cause a coating failure at the time of forming an image forming layer or the like and does not cause pinholes or uneven development during heat development. Another object of the present invention is to provide a method for producing a heat-developable image recording material having such characteristics.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, prepared by adding an image forming additive material filtered through a filtration filter having a specific pore size to latex. The present inventors have found that an excellent heat-developable image recording material exhibiting the desired effect can be produced by forming an image forming layer using an aqueous coating solution for the image forming layer, and have provided the present invention. That is, the present invention relates to a heat-developable image recording material having an image-forming layer on at least one of the supports and subjected to a heat-development process at a developing temperature of 80 ° C. or more and 140 ° C. or less. The aqueous coating solution for the image forming layer contains at least 50% by weight (in terms of dry solid content) or more of 2%
prepared by adding to a latex after filtering through a filtration filter having a pore size of m or more and 30 μm or less,
A heat-developable image recording material, wherein the image-forming layer is formed by applying and drying the aqueous image-forming coating solution. The image-forming layer of the heat-developable image-recording material of the present invention is preferably formed using an image-forming aqueous coating solution that has been filtered with a filtration filter having a pore size of 2 μm or more and 30 μm or less before coating. Further, it is more preferable that the aqueous coating solution for the image forming layer is defoamed before coating. Further, the present invention provides a method for producing a heat-developable image recording material, comprising an image-forming layer on at least one of the supports, wherein the heat-development is carried out at a development temperature of 80 ° C. or more and 140 ° C. or less. The aqueous coating solution for the image forming layer comprising the additive material is added to the latex after at least 50% by weight (in terms of dry solids) or more of the additive material for the image forming layer is filtered through a filter having a pore size of 2 μm to 30 μm. The method further comprises a step of forming the image forming layer by applying and drying the prepared aqueous coating solution for image formation prepared by the above method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a heat-developable image recording material of the present invention and a method for producing the same will be described in detail. The heat-developable image recording material of the present invention has an image-forming layer on at least one of the supports, and is subjected to a heat-development treatment at a developing temperature of 80 ° C or more and 140 ° C or less. Its features are:
An aqueous coating solution for image formation prepared by filtering at least 50% by weight (in terms of dry solid content) or more of the additive material for an image forming layer through a filtration filter having a pore size of 2 μm or more and 30 μm or less, and then adding the latex to a latex, is coated. The point is that the image forming layer is formed by drying. The aqueous coating solution used to form the image forming layer in the invention contains latex as a binder. The constituent components of the aqueous coating solution for the image forming layer other than the latex are referred to as "added materials for the image forming layer" in this specification. Latex is a binder in which a water-insoluble hydrophobic polymer is dispersed as fine particles in a water-soluble dispersion medium. The latex used in the present invention has a dispersed state in which the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or partially hydrophilic in the polymer molecule. Any of those in which the molecular chains themselves are molecularly dispersed may be used. Regarding the latex preferably used in the present invention, `` Synthetic resin emulsion (Taira Okuda, Hiroshi Inagaki edited,
Published by The Society of Polymer Publishing (1978)), `` Application of synthetic latex
(Edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, published by the Society of Polymer Publishing (1993)), `` The Chemistry of Synthetic Latex (Souichi Muroi, Published by the Society of Polymer Publishing (1970)) '', etc. ing. The average particle size of the latex dispersed particles of the present invention is 1 to
It is 500 nm, more preferably 5 to 300 nm, particularly preferably 10 to 200 nm. There is no particular limitation on the particle size distribution of the dispersed particles, and they may have a wide particle size distribution or a monodispersed particle size distribution. The latex of the present invention may be a polymer latex having a uniform structure, or a so-called core / shell type polymer latex. In this case, the glass transition temperature of the polymer constituting the core and the glass transition temperature of the polymer constituting the shell may be different.

The glass transition temperature (T) of the polymer contained in the polymer latex used as the binder for the image forming layer
g) is −50 ° C. to 1 from the viewpoint of film strength and prevention of damage due to damage.
It is particularly preferred that the temperature be in the range of 00 ° C. The minimum film formation temperature (MFT) of the polymer latex of the present invention is from -30 ° C to 9
It is preferably 0 ° C, more preferably about -30 ° C to 80 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. The film forming aid is also called a temporary plasticizer, and is an organic compound (usually an organic solvent) that lowers the minimum film forming temperature of the polymer latex. Issued (197
0)) ”and the like. Examples of the polymer species used in the polymer latex for the image forming layer include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. . The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is 5,000 to 1,000 in weight average molecular weight.
000, preferably about 10,000 to 100,000. If the molecular weight is too small, the mechanical strength as a binder is insufficient, and if it is too large, the film-forming property is poor, which is not preferable.

Specific examples of the polymer latex used in the aqueous coating solution for the image forming layer of the heat-developable image recording material of the present invention include the following. Methyl methacrylate / ethyl methacrylate / methacrylic acid copolymer, methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene /
Acrylic acid copolymer, styrene / butadiene / acrylic acid copolymer, styrene / butadiene / divinylbenzene / methacrylic acid copolymer, methyl methacrylate / vinyl chloride / acrylic acid copolymer, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer can be exemplified. . These polymers are also commercially available, and the following polymers can be used. For example, as an example of acrylic resin, Sebian A-
4635,46583, 4601 (all manufactured by Daicel Chemical Industries, Ltd.), Ni
pol Lx811, 814, 821, 820, 857, 857x2 (all manufactured by Zeon Corporation), VONCORT R3340, R3360, R3370, 4280, 28
30, 2210 (manufactured by Dainippon Ink and Chemicals, Inc.), Julimer ET-410, 530, SEK101-SEK301, FC30, FC35 (manufactured by Nippon Pure Chemical Co., Ltd.), Polysol F410, AM200, AP50 (manufactured by Showa High School) Molecule Co., Ltd.), VONCORT R3370, 4280, Nipol L
x857, methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene / acrylic acid copolymer, Nipol G57 vinyl chloride resin
6. Polyester resins such as Alon D5071 of vinylidene chloride resin, and FINETEX ES650, 611, 675, 850 (all manufactured by Dainippon Ink & Chemicals, Inc.), WD-size, WMS (all manufactured by Eastman Chemical), polyurethane HYD as resin
LACSTAR 731 is a rubber-based resin such as RAN AP10, 20, 30, 40, VONDIC 1320NS (all manufactured by Dainippon Ink and Chemicals, Inc.)
As vinyl chloride resin such as 0K, 3307B, 4700H, 7132C, LQ-618-1 (manufactured by Dainippon Ink & Chemicals, Inc.), Nipol Lx416, 410, 430, 435, 2507 (manufactured by Nippon Zeon Co., Ltd.) Is N
ipol G351, G576 (Nippon Zeon Co., Ltd.), etc., as vinylidene chloride resin, L502, L513 (all Asahi Kasei Kogyo Co., Ltd.), Aron D7020, D5040, D5071 (all Toa Gosei Co., Ltd.), etc. Chemipearl S1 as olefin resin
20, SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.) and the like. Further, a styrene / butadiene-based polymer latex is preferably used, and specifically, LACSTAR3307B, Nipol Lx430, and 435 of a rubber-based resin are preferably used.

In the present invention, if necessary, a hydrophilic polymer may be contained in a range of 25% by weight or less of the whole binder. For example, various kinds of gelatins (alkali treatment, acid treatment,
Enzyme treatment, modification (phthalation, succination, trimellitation, etc.), denaturation, gelatin with special molecular weight distribution etc.), substituted or unsubstituted celluloses, hydrophilic binders such as natural gum arabic, dextran, etc. polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyacrylamide, polyacrylate (Na, K, or the like may be NH _4), polyvinyl sulfonate (Na, K, etc. NH _4), polystyrene sulfonates (Na, K, etc. NH ₄₎ or the like may be added. The amount of the hydrophilic polymer to be added is preferably 25% by weight or less of all the binders in the layer, more preferably 15% by weight.
The following is preferred. Latex is generally filtered during manufacture. By performing filtration, it is possible to remove a stagnation or the like generated in a liquid stagnant portion of the reaction vessel or a portion that is likely to be dried due to high temperature during production.

The latex concentration of the coating solution for at least one image forming layer of the present invention is 1 to 40% by weight, more preferably 5 to 35% by weight, particularly preferably 5 to 3% by weight.
0% by weight. The content of the latex in the photothermographic material after coating and drying is 0.5 to 10.0 g.
/ M ² , more preferably 1 to 5.0 g / m ² . Hereinafter, typical additive materials for the image forming layer used in the coating solution for the image forming layer will be described. Generally, since the latex binder is handled in a water-dispersed state, the additive material for the image forming layer is also dissolved or dispersed in a solution mainly composed of water. However, when the coating material for an image forming layer is prepared by mixing the additive material for an image forming layer with other components, it is not necessary to mix the additive material for an image forming layer as an aqueous solution. Therefore, an organic solvent or a mixture of an organic solvent and water may be used as the solvent or the dispersion medium, and there is no problem as long as the coating solution for the image forming layer is a stable solution. The coating liquid for an image forming layer having a latex may be subjected to crosslinking using a curing agent. Further, it is particularly preferable to use a hydrophilic polymer in combination. As a preferable crosslinking agent, a known curing agent can be used. As these, for example, the compounds described in RD307105, the literature in Chapter X can be used. Among them, use of a polyfunctional isocyanate compound having two or more isocyanate groups or an epoxy compound is preferred. By using such a curing agent, a high molecular weight can be obtained, and the cross-linking of a latex or a hydrophilic polymer can prevent the film from being softened due to a high temperature during thermal development, thereby forming a strong film-forming film. it can.

The image forming layer contains various additives for image formation in addition to latex as a binder. They include long-chain fatty acid silver (eg, silver behenate, silver stearate, etc.), photosensitive silver halide (eg, silver chloride, silver chlorobromide, silver iodochlorobromide, etc.), ultra-high contrast agents, high contrast enhancement Agents, sensitizing dyes, antifoggants, dyes, UV agents, film quality improvers (eg, colloidal silica), surfactants, pH adjusters, etc., as long as they can be contained in the image forming layer. Not done. These inclusions may be materials that dissolve in water or may be added in the form of dispersed particles. In general, these materials are often subjected to rough dust removal at the raw material stage, but even in such a case, it is often found that they contain dust of a size that cannot be visually observed. To avoid this problem, some materials use a full-fledged filter to remove dust. However, when coarse particles are contained when finally provided as a coating solution, the dispersion often loses dispersion stability, and as a result, coarse particles are generated in the coating solution due to aggregation or the like. However, this may cause a problem on an image.

Therefore, in the present invention, the additive material for the image forming layer to be added to the latex or the like at the time of forming the aqueous coating solution for the image forming layer is to remove the coarse particles existing in the solution or dispersion of the raw material before the addition. It is important to remove by filtration. The "filtration" described here is filtration by a filtration filter, and the type and structure of the filtration filter are not particularly limited, provided that the filtration filter can remove foreign substances that do not pass through a pore size of 2 to 30 μm. Anything is fine. The system for removing coarse particles using these filtration filters is also not particularly limited, and is not particularly limited as long as no major problem occurs in filtration. In the present invention, the filtration pore size of the filtration filter is 2 μm or more and 30 μm or less, more preferably 2 μm or less.
A filtration filter having a pore size of not less than m and not more than 20 μm, and in some cases not less than 2 μm and not more than 10 μm is preferably used. Examples of materials for these filtration filters include paper,
Cloth, cellulose acetate polymer, polysulfone,
Polyether sulfone, polyacrylonitrile, polyether, fluorine (polyvinylidene fluoride) polymer,
Examples thereof include polyamide, polyimide, polyethylene, polypropylene, stainless steel, and ceramic. The form is a flat membrane, a cartridge membrane, a hollow fiber membrane, or the like, and is not particularly limited. The filtration filter preferably used in the present invention is a flat membrane made of cloth or filter paper, and more preferably a cartridge type filtration filter or a ceramic filtration filter. In order to filter the added material for an image forming layer of the present invention with such a membrane (disk type) or a cartridge filtration filter, it is particularly preferable to use a housing provided with a cartridge filtration filter.

Many of these filtration filters are commercially available from Fuji Photo Film Co., Ltd. Among them, Fujifilm microfiltration filter PPE type (polypropylene filter) made of cartridge type polypropylene nonwoven fabric, PPF03 (3 μm), PPF10
(10 μm), PPF30 (30 μm), Fujifilm microfiltration filter FPC3P (polypropylene woven cloth, 3 μm), FPC10P (10 μm), FPC20
P (20 μm) or the like can be preferably used. Furthermore, Paul Epocell (various sizes) and profile filters (2, 3, 5, 1) marketed by Paul Corporation
0 μm pore size), CN commercially available from Millipore
03 (3 μm), CN06 (6 μm), CN25 (25 μm)
μm) can also be used. These filtration filters have a large area with a pleated flat membrane, and are compact and space-saving.

The use of these filtration filters is not particularly limited, as long as the addition material solution for the image forming layer is not clogged and coarse particles can be removed. However, in general, the above filtration filter is
It is effective without taking up the installation area by using it mounted on the housing. Preferred devices for these housings include stainless steel FS1-1, 1-2, 1-3, or FS3, FS6, FS12, FS-24, etc., commercially available from Fuji Photo Film Co., Ltd.
Further, FPM1-1 made of polypropylene or the like is used. The size and shape of the housing are not particularly limited, and may be circular, square, or a single filter loaded type, and may be loaded with two or more filters at a time. Furthermore, it can also be used by connecting two or more filters to greatly increase the filter area. Further, in the present invention, a flat membrane type can also be used. These are used in a very common filtration method.A filtration filter is installed on the receiving part, the device that will be the liquid storage part is firmly fixed on it, and the filter mounting part is tightened with a tightening member to filter the filtrate. It is to prevent leakage. At this time, packing is mounted on the filter installation part to prevent liquid leakage.

When filtering the additive material solution for the image forming layer of the present invention, there is no limitation on the pressure for sending the solution. Is preferably removed. In particular, pressurization is often carried out by a method in which the coating solution is sent by a pump or the like, but it is also preferable to arrange the coating solution at a higher position than the filter and to filter the solution by natural pressure. Furthermore, it is preferable to apply pressure to the coating liquid with a gas, in which case the tank in which the coating liquid is present is actually a closed system. When applying pressure with a pump at the time of liquid feeding, pressurization by its own weight, or even pressurization with gas, especially when applying pressure, unless the filter is damaged or clogged and the performance is deteriorated, Not limited. For example, the pressure applied to the filtration filter is 0.00
5 kg / cm ² or more 50 kg / cm ² by weight, more preferably 0.1 kg / cm ² or more 10 kg / cm ^2, particularly preferably preferably 0.01 kg / cm ² or more 5 kg / cm ^2. In addition, when the filtrate is filtered under reduced pressure, the degree of vacuum is preferably 750 mmHg or less and 10 mmHg, more preferably 700 mmHg or less and 100 mmHg. Particularly, 400 mmHg or less of 700 mmHg or less is preferable.

The present invention is characterized in that the additive material for the image forming layer is filtered before mixing with the latex.
The time from filtration to application is not particularly limited. It is also preferable to perform filtration with the above-mentioned filtration filter even after preparing the aqueous coating solution for the image forming layer, but the time from filtration to application is not particularly limited. As long as the filtered additive material for the image forming layer or the aqueous coating solution for the image forming layer does not form coarse particles, it may be considerably before the application. However, in view of production efficiency, filtration is generally 12 minutes from immediately before application.
It is preferably within 1 month, more preferably within 6 months from immediately before application, even more preferably within 1 month from immediately before application, and particularly preferably within 15 days from immediately before application. Here, "before coating" includes a case where the additive material liquid is present in the middle of a liquid feed pipe from the tank storing the additive material liquid to the coating greaser, and in this case, so-called online filtration is preferable. It should be noted that there is no problem even if the filtered additive material solution or the image forming layer aqueous coating solution is temporarily stored in a stock tank other than the step of final application.

The aqueous coating solution for the image forming layer is preferably defoamed before coating. Here, “before coating” refers to any timing between the time when the aqueous coating solution for the image forming layer is prepared and the time when coating is performed. For this reason, the aqueous coating solution for image formation may be defoamed after preparation and then filtered, or the aqueous coating solution may be filtered and defoamed after preparation. It is preferable to form an image forming layer using the defoamed coating solution, since coating streaks, coating repelling, and pinholes are less likely to appear on the heat-developable image recording material of the present invention.
The heat-developable image recording material of the present invention may have a plurality of image forming layers. When there are a plurality of image forming layers, at least one of them is formed by using the above-mentioned aqueous coating solution for image formation. Preferred is a case where all the image forming layers are formed using the above-mentioned aqueous coating solution for image formation.

Hereinafter, the constituent layers of the present invention will be described. First, materials used for at least one image forming layer will be described. Organic silver salts and silver halides are contained in the image forming layer as essential materials, but other materials do not necessarily have to be contained in the image forming layer. The photosensitive silver halide used in the present invention may be any of silver chloride, silver chlorobromide, and silver iodochlorobromide. Further, the distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously. The method for forming the photosensitive silver halide in the present invention is well known in the art, and for example, using the method described in Research Disclosure No. 17029 of June 1978, and U.S. Pat.No. 3,700,458. Can be. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method in which a silver supply compound and a halogen supply compound are added to another polymer solution to prepare photosensitive silver halide grains and mixed with an organic silver salt can be used.
In the present invention, the latter method can be preferably used. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically 0.20 μm or less, more preferably 0.01 μm or more.
It is preferably 0.15 μm or less, more preferably 0.02 μm or more and 0.12 μm or less. The grain size as used herein refers to the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical particles, rod-shaped particles, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited, but the spectral sensitizing efficiency when a spectral sensitizing dye is adsorbed is high.
The proportion occupied by the [100] plane is preferably high. The ratio is preferably 50% or more, more preferably 65% or more,
80% or more is more preferable. The ratio of the Miller index [100] plane was determined by T. Tani; J. Imaging Sci., 29, 165 (1985) using the dependence of the adsorption of sensitizing dye on the [111] and [100] planes. It can be determined by the method described.

The photosensitive silver halide grains are the same as those in the periodic table.
It preferably contains a metal or a metal complex of Group VII or Group VIII (Groups 7 to 10). Of the periodic table
Rhodium, rhenium, ruthenium, preferably as the central metal of the Group VII or Group VIII metal or metal complex
Osnium and iridium. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is 1n per mole of silver.
Mol to 10 mmol, preferably 10 nmol to 100 μm.
A molar range is more preferred. As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used.

The silver halide emulsion is preferably chemically sensitized. As the method of chemical sensitization, known methods such as a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, and a noble metal sensitization method can be used, and these are used alone or in combination. When used in combination, for example,
Sulfur sensitization method and gold sensitization method, sulfur sensitization method and selenium sensitization method and gold sensitization method, sulfur sensitization method and tellurium sensitization method and gold sensitization method, sulfur sensitization method and selenium sensitization method Tellurium sensitization and gold sensitization are preferred. The sulfur sensitization used in the present invention is usually carried out by adding a sulfur sensitizer and stirring the emulsion at a high temperature of 40 ° C. or higher for a certain period of time. As the sulfur sensitizer, known compounds can be used.For example, in addition to sulfur compounds contained in gelatin, various sulfur compounds such as thiosulfates, thioureas, thiazoles, rhodanines and the like are used. be able to. Preferred sulfur compounds are thiosulfates and thiourea compounds. The amount of sulfur sensitizer added is
It changes under various conditions such as pH, temperature, size of silver halide grains and the like during chemical ripening, but it is 10 ^-7 to 10 ^-2 mol, preferably 10 ^-5 mol, per mol of silver halide.
10 to ³ mol.

As a method for preparing silver halide, a so-called halide method in which a part of silver of an organic silver salt is halogenated with an organic or inorganic halide is also preferably used. The organic halide used herein may be any compound as long as it is a compound that reacts with an organic silver salt to generate a silver halide, and includes N-halogenimide (N-bromosuccinimide, etc.), quaternary nitrogen halide (e.g. Tetrabutylammonium bromide), an association of a quaternary nitrogen halide and a halogen molecule (pyridinium bromide perbromide), and the like. As the inorganic halogen compound, any compound may be used as long as it is a compound which reacts with an organic silver salt to generate silver halide, and includes an alkali metal or ammonium halide (such as sodium chloride, lithium bromide, potassium iodide, and ammonium bromide). ), Alkali earth metal halides (calcium bromide, magnesium chloride, etc.), transition metal halides (ferric chloride, cupric bromide, etc.), metal complexes with halogen ligands (sodium iridium bromide) , Ammonium rhodate, etc.), halogen molecules (bromine, chlorine, iodine)
and so on. Further, a desired organic / inorganic halide may be used in combination.

In the present invention, the amount of the halide to be added is preferably from 1 mmol to 500 mmol, more preferably from 10 mmol to 250 mmol, as a halogen atom per 1 mol of the organic silver salt.
mmol is more preferred. The organic silver salt that can be used in the present invention is relatively stable to light, but at 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. It is a silver salt that forms a silver image when heated as described above. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Silver salts of organic acids, especially silver salts of long-chain fatty carboxylic acids (with 10 to 30, preferably 15 to 28 carbon atoms) are preferred. The ligand is 4.0 to 10.
Complexes of organic or inorganic silver salts having a complex stability constant in the range of 0 are also preferred. The silver donor material can preferably comprise about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include:
Silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and Including silver camphorate, mixtures thereof and the like.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but a needle crystal having a short axis and a long axis is preferable. In the present invention, the minor axis is 0.01 μm or more and 0.2 μm or more.
The length is preferably 0 μm or less, the major axis is 0.10 μm or more and 5.0 μm or less, the minor axis is 0.01 μm or more and 0.15 μm or less, and the major axis is 0.10 μm or more and 4.0 μm or less. The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the percentage of the value obtained by dividing the standard deviation of the length of each major axis by the minor axis and major axis, respectively, is preferably 100% or less, more preferably 80% or less,
More preferably, it is 50% or less.

The organic silver salt that can be used in the present invention includes:
Preferably, desalting can be performed. The desalting method is not particularly limited, and a known method can be used. A known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, or floc-forming water washing by a coagulation method can be preferably used. For the purpose of obtaining fine particles having a small particle size and no aggregation, a method of preparing a solid fine particle dispersion using a dispersant is used for the organic silver salt that can be used in the present invention. The method of dispersing the organic silver salt into solid fine particles is carried out by using a known fine-granulating means (for example, ball mill, vibrating ball mill, planetary ball mill, sand mill, colloid mill, jet mill, roller mill, high-pressure homogenizer) in the presence of a dispersing aid. Used and can be dispersed mechanically. When the organic silver salt is formed into solid fine particles using a dispersant, for example,
Synthetic anionic polymers such as polyacrylic acid, copolymers of acrylic acid, maleic acid copolymers, maleic acid monoester copolymers, acryloylmethylpropanesulfonic acid copolymers, and semi-synthetic materials such as carboxymethyl starch and carboxymethyl cellulose Anionic polymers, anionic polymers such as alginic acid and pectic acid,
52-92716, anionic surfactants described in WO88 / 04794, etc., compounds described in JP-A-9-179243, or known anionic, nonionic, cationic surfactants, and others Known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or naturally occurring polymer compounds such as gelatin can be appropriately selected and used.

[0027] While the organic silver salt can be used in a desired amount, indicated by the amount of heat developable image recording material 1 m ² per 0 as silver.
1 to 5 g / m ² is preferred, and more preferably 0.5 to 3 g / m ²
It is. The heat-developable image recording material of the present invention preferably contains a reducing agent for an organic silver salt. The reducing agent for the organic silver salt may be any substance that reduces silver ions to metallic silver, preferably an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred. The reducing agent is 5 to 50% based on 1 mol of silver on the surface having the image forming layer.
(Mol), more preferably 10 to 40% (mol). The layer to which the reducing agent is added may be any layer on the side having the image forming layer. When it is added to a layer other than the image forming layer, it is preferable to use a relatively large amount of 10 to 50% (mol) with respect to 1 mol of silver. Further, the reducing agent may be a so-called precursor which is derivatized so as to have a function effectively only during development. In heat-developable image recording materials using organic silver salts, a wide range of color toning agents are disclosed in
No. -6077, No. 47-10282, No. 49-5019, No.
No. 49-5020, No. 49-91215, No. 49-91215, No. 50-2524, No. 50-32927, No. 50-67132
No. 50-67641, No. 50-114217, No. 51-
No. 3223, No. 51-27923, No. 52-14788, No.
No. 52-99813, No. 53-1020, No. 53-76020, No. 54-156524, No. 54-156525, No. 61-183
No. 642, JP-A-4-56848, JP-B-49-10727, JP-A-54-20333, U.S. Patent 3,080,254,
3,446,648, 3,782,941 and 4,123,
No. 282, No. 4,510,236, British Patent 1380795
And Belgian Patent No. 841910.

In order to obtain a high-contrast image, the heat-developable image recording material of the present invention preferably contains a super-high contrast agent in the image forming layer and / or the layer adjacent thereto. Further, in the present invention, for forming a super-high contrast image, a high contrast accelerator can be used in combination with the above super-high contrast agent. For example, the amine compounds described in U.S. Pat. 5,545,5
The acrylonitriles described in the specification of Japanese Patent Application No. 07, specifically C
N-1 to CN-13, hydrazine compounds described in the specification of US Pat. No. 5,558,983, specifically, CA-1 to CA-6, Japanese Patent Application No. 8-132836.
Salts, specifically A-1 to A
-42, B-1 to B-27, C-1 to C-14 and the like can be used. As the sensitizing dye in the present invention, any dye can be used as long as it can spectrally sensitize the silver halide grains in a desired wavelength region when adsorbed on the silver halide grains. As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, and the like can be used.

As an example of spectral sensitization to red light, He-Ne
For lasers, so-called red light sources such as red semiconductor lasers and LEDs, the I-1 described in JP-A-54-18726 is used.
To I-38 compound, I-1 to I-35 compound described in JP-A-6-75322 and I- described in JP-A-7-287338.
Compounds 1 to I-34, Dyes 1 to 20 described in JP-B-55-39818, I-1 to I-3 described in JP-A-62-284343
From compound 1 and I-1 described in JP-A-7-287338
The compound of I-34 and the like are advantageously selected. 750-1400nm
Can be spectrally advantageously sensitized to various semiconductor dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes. Useful cyanine dyes include, for example, thiazoline nuclei, oxazoline nuclei, pyrroline nuclei, pyridine nuclei,
A cyanine dye having a basic nucleus such as an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, and an imidazole nucleus. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example,
U.S. Pat.Nos. 3,761,279 and 3,719,495,
3,877,943, British Patent 1,466,201, ibid.
469,117, 1,422,057, JP-B-3-1039
No. 1, JP-A-6-52387, JP-A-5-341432,
It may be appropriately selected from known dyes as described in JP-A-6-94781 and JP-A-6-301141.

Further, as a dye forming a J-band, Example 5 of US Pat. Nos. 5,510,236 and 3,871,887 is used.
The dyes described in JP-A-2-96131 and JP-A-59-48753 are disclosed and can be preferably used in the present invention. The silver halide emulsions and / or organic silver salts of the present invention are further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and have a reduced sensitivity during storage in inventory. Can be stabilized. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are
U.S. Pat.Nos. 2,131,038 and 2,694,716 thiazonium salts described in U.S. Pat.Nos. 2,886,437 and 2,444,605 Azaindene described in U.S. Pat. salt,
Urazole described in U.S. Pat.No. 3,287,135, sulfocatechol described in U.S. Pat.No. 3,235,652, oxime described in British Patent No. Described polyvalent metal salts, thyuronium salts described in U.S. Pat.
Palladium, platinum and gold salts described in 6,263 and 2,597,915, halogen-substituted organic compounds described in U.S. Pat.Nos. 4,108,665 and 4,442,202, U.S. Pat. No. 4,137,079, No. 4,138,365 and No.
There are a triazine described in 4,459,350 and a phosphorus compound described in U.S. Pat. No. 4,411,985.

The antifoggant preferably added to the image forming layer may be added by any method such as a solution, a powder and a dispersion of solid fine particles. Dispersion of solid fine particles can be performed by a known means of micronization (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.)
Done in When dispersing the solid fine particles, a dispersing aid may be used. The heat-developable image recording material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. In the present invention, a mercapto compound, a disulfide compound, and a thione compound can be contained for controlling development by suppressing or promoting development, for improving spectral sensitization efficiency, for improving storage stability before and after development, and the like. .

In the present invention, 50% by weight or more (in terms of dry solid content) of the additive material for the image forming layer is 2 μm to 30%.
The mixture is filtered with a filtration filter having a pore size of not more than μm and mixed with latex to prepare an aqueous coating solution for image formation. The above 50% by weight or more means that the ratio of the filtered additive material for the image forming layer to the total solid content other than the latex component after the image forming layer is dried is 50% by weight or more. The amount of the additional material for the image forming layer to be filtered is more preferably 70% by weight or more, and particularly preferably 80% by weight or more. As the rate of filtration of the additional material for the image forming layer is higher, a more uniform solution of the coating solution for the image forming layer can be prepared, and the cause of streaks and unevenness during coating can be eliminated.
In the present invention, the reason that filtration of all the additional materials for the image forming layer is not required is that some materials do not originally contain coarse particles or coarse substances.

Next, binders such as a protective layer, an intermediate layer, a back layer, and a back protective layer which are non-image layers will be described. As a binder for these layers, a polymer binder is preferably used, and these are obtained by dispersing a water-insoluble hydrophobic polymer as fine particles in a water-soluble dispersion medium, and a binder for an image layer can be preferably used. The glass transition temperature (Tg) of the polymer of the polymer latex used as the binder in the non-image layer has a different preferable temperature range between the back layer and the image forming layer. The back layer has a glass transition temperature of 25 ° C. to 100 ° C. in particular from the viewpoint of film strength and prevention of adhesion failure in order to come into contact with various devices, and the image forming layer promotes diffusion of photographic useful materials during heat development, and has a high Dmax. -To obtain good photographic properties such as low fog-
A glass transition temperature of 30C to 40C is preferred, and a glass transition temperature of 0C to 40C is particularly preferred. The minimum film formation temperature (MFT) of the polymer latex is -30 ° C to 90 ° C,
More preferably, it is about 0 ° C to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. The film-forming assistant is also called a temporary plasticizer and is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of the polymer latex. ))"It is described in.

Next, the present invention is characterized in that at least one additional material for the image forming layer for the image forming layer is filtered, which has the greatest effect on the image. However, in addition to this image forming layer, an intermediate layer, a protective layer, and other functional layers may be mentioned as layers that affect the state of the coated surface. Therefore, in the present invention, it is very preferable that the added materials other than the image forming layer are filtered in advance before coating. In particular, when an additive material for forming an image is added to a layer other than the image forming layer, it is preferable to perform filtration in order to prevent unevenness of the image and pinhole defects. The intermediate layer, protective layer or functional layer described in the present invention generally contains a latex binder as a main component and contains other water-soluble compounds and dispersing materials. For example, as materials other than photosensitive materials, ultra-high contrast agents, high contrast accelerators, sensitizing dyes, antifoggants, dyes, UV agents, film quality improvers (such as colloidal silica), surfactants,
There are various types such as pH adjusters, and there is no particular limitation. Above all, a slipping agent, a matting agent, a surfactant for application, an antistatic agent, and a film quality improving agent (such as colloidal silica) are added to the protective layer liquid to impart surface characteristics. These materials will be described later. In filtering the coating solution for the non-image layer on the image forming layer side other than the image forming layer, the same filter as described in the filtration of the coating solution for the image forming layer can be used. At that time, the filtration pore size of the filtration filter is 2 μm or more and 30 μm or less,
More preferably, it is 2 μm or more and 10 μm or less, particularly preferably 2 μm or more and 5 μm or less, and in some cases, a filtration filter having a pore size of 2 μm or more and 3 μm or less is preferably used.

In particular, since the matting agent is generally provided with large matting agent particles in order to provide a convex portion on the surface, the pore size of the filtration filter requires a certain size, for example, preferably 2 μm or more and 30 μm or less. More preferably, it is 5 μm or more and 25 μm or less. Furthermore, when preparing a matting agent coating solution in advance, only the matting agent solution is separately filtered through a filter having a large pore size, and the coating solution of another material is filtered through a matting agent with a filtering filter having a small pore size. It is preferable to mix and use them together. Preferred amounts of the matting agent are 5 to 400 mg / m ² ,
In particular from 5 to 100 mg / m ^2. The matting agent used in the present invention may be any solid particles which do not adversely affect the photographic properties. Examples of inorganic matting agents include silicon dioxide, oxides of titanium and aluminum, carbonates of zinc and calcium, sulfates of barium and calcium, silicates of calcium and aluminum, and examples of organic matting agents include cellulose. Mention may be made of organic polymeric matting agents such as esters, polymethyl methacrylate, polystyrene or polydivinylbenzene and copolymers thereof. In the present invention, a porous matting agent described in JP-A-3-109542, page 2, lower left column, line 8 to page 3, upper right column, line 4;
No. 127142, page 3, upper right column, line 7 to page 5, lower right column, line 4; matting agent surface-modified with alkali;
It is more preferable to use an organic polymer matting agent described in paragraph Nos. "0005" to "0026" of JP-A-42. Further, two or more of these matting agents may be used in combination. For example, a combination of an inorganic matting agent and an organic matting agent, a combination of a porous matting agent and a non-porous matting agent, a combination of an amorphous matting agent and a spherical matting agent, mats having different average particle sizes. (For example, a matting agent having an average particle size of 1.5 μm or more and a matting agent having an average particle size of 1 μm or less described in JP-A-6-118542).

Next, the slip agent added to the coating solution for the protective layer on the image forming layer side or the back side in the present invention will be described. In the slip agent-dispersed particles preferably used in the present invention, a heat-developable image recording material is prepared by coating and drying, and is present on the surface or in the vicinity of the surface to reduce friction with a contacting partner substance. If it is present, it is not particularly limited, but is preferably a slip agent represented by the general formula (1). Formula (1) (R ¹ COO) _p L (COOR ² ) _q (wherein R ¹ and R ² are a substituted or unsubstituted alkyl, alkenyl, aralkyl or aryl group having 1 to 60 carbon atoms) And when p or q is 2 or more, a plurality of R ¹ and R ² may be the same or different from each other; L is a p + q-valent carbon atom which may contain an oxygen atom or a sulfur atom. A hydrogen group, p and q each represent an integer of 0 to 6 and 1 ≦ p + q ≦ 6) The total number of carbon atoms in the compound represented by the general formula (1) is not particularly limited, but is generally 20. More preferably, 30
The above is more preferable, for example, 40 to 100, and more preferably 5
It is 0-100, especially 50-80.

Examples of the substituent which the alkyl group, alkenyl group, aralkyl group or aryl group may have in the definition of R ¹ and R ² include a halogen atom, a hydroxy group, a cyano group, an alkoxy group and an aryloxy group. Group, alkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, amino group, acylamino group, sulfonylamino group, ureido group, carbamoyl group, sulfamoyl group, acyl group, sulfonyl group, sulfinyl group, aryl group and alkyl group Can be mentioned. These groups may further have a substituent. Preferred substituents are a halogen atom, a hydroxy group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an acylamino group, a sulfonylamino group, an acyl group, and an alkyl group. As a halogen atom,
A fluorine atom and a chlorine atom are preferred. The alkyl component in the alkoxy group, the alkylthio group and the alkoxycarbonyl group is the same as the alkyl group of R ² described later. The amino group of the acylamino group and the sulfonylamino group may be an N-substituted amino group, and the substituent is preferably an alkyl group.
The group bonded to the acylamino group, the carbonyl group of the acyl group and the sulfonyl group of the sulfonylamino group are an alkyl group and an aryl group, and the above-mentioned alkyl group is preferable.

R ¹ and R ^{2 each} have ^{1 to} 60 carbon atoms, preferably 1 to 40 carbon atoms, more preferably 10 to 40 carbon atoms.
A substituted or unsubstituted alkyl group, alkenyl group, aralkyl group, or aryl group.The alkyl group, alkenyl group, and aralkyl group may be linear, branched, or include a cyclic structure, or a mixture thereof. May be. Examples of preferred R ¹ and R ² are methyl, ethyl, propyl, butyl, octyl, t-octyl, dodecyl, tetradecyl, hexadecyl, 2-hexyl decyl, octadecyl, and _{C n H 2n-1 (n} 20~6
0), eicosyl, docosanyl, mericinyl, octenyl, myristoleyl, oleyl, ersyl, phenyl, naphthyl, benzyl, nonylphenyl, dipentylphenyl, cyclohexyl, and groups having the above substituents.

L is a p + q-valent hydrocarbon group which may contain an oxygen atom or a sulfur atom. Although the carbon number of the hydrocarbon group is not particularly limited, it is preferably 1 to 60, more preferably 1 to 40, and still more preferably 10 to 40. “p + q valence” in a p + q valent hydrocarbon group means that p + q hydrogen atoms in the hydrocarbon are removed and p R ¹ COO— groups and q R ² OCO— groups are bonded thereto. Is shown. p and q represent an integer of 0 to 6 and 1 ≦ p + q
≦ 6, preferably 1 ≦ p + q ≦ 4. Also,
It is preferred that either p or q is 0. The compound represented by the general formula (1) may be a synthetic product or a natural product. Natural compounds or synthetic compounds made from natural higher fatty acids or alcohols, even if they are synthetic, include those having different numbers of carbon atoms, straight-chain and branched ones, and mixtures of these. There is nothing wrong with using. From the viewpoint of quality stability of the composition, a synthetic product is preferable. In particular, for natural products, various chemicals and additives are used in the collecting and refining process, and contamination of impurities is inevitable. For example, a serious problem such as failure of coating repelling due to mixing of a silicone-based antifoaming agent occurs. As the compound, a compound which is a main component of the material is represented. Specific examples of preferred compounds represented by the general formula (1) are shown below.

[0040]

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These compounds are described, for example, in JP-A-58-1983.
A part is described in 90633. In addition to the above compounds, montanic acid esters, carnauba wax, oleostock and the like can also be added as examples of natural products.
The general formula (1) has a melting point of 50 ° C to 200 ° C, more preferably 60 ° C to 200 ° C, and particularly preferably 70 ° C to 160 ° C. In the present invention, in addition to the compound represented by the general formula (1), it can be used in combination with other known slip agents. Preferred examples of the known slipping agent are similar to the compound represented by the general formula (1), for example, higher aliphatic amides described in US Pat. No. 4,275,146, US Pat. No. 933,516, higher fatty acids or metal salts thereof, other higher alcohols and derivatives thereof, polyethylene wax, paraffin wax, microcrystalline wax, polyoxyethylene alkylphenyl ether compounds and the like. In addition, natural fats and oils, waxes and oils, such as beeswax, can also be used in combination. In the present invention, when these are used in an aqueous solution, they are added in the form of a dispersion.

The dispersed particles of the slipping agent represented by the general formula (1) are added to the coating solution for the protective layer in the form of a dispersion in an aqueous solution. In this case, another organic solvent can be appropriately selected and contained in the aqueous dispersion. Preferred are alcohols, ketones, glycol derivatives, lower fatty acid esters, haloalkanes, and hydrocarbons. In particular, in a solvent system in which water is mixed and used, the solvent is selected from alcohols, ketones, and glycol derivatives that are water and a homogeneous solvent.
The use of ketones, lower fatty acid esters and haloalkanes is preferred. At this time, the ratio of water to the organic solvent is 100 to
50/0 to 50 VOL%, more preferably 100 to 50 VOL%
75/0 to 25 VOL%. Fine dispersions are known dispersion techniques, for example, dispersion by mechanical shearing force, ultrasonic dispersion,
It is obtained by a precipitation method by mixing two liquids and the like.

The slip agent-dispersed particles represented by the general formula (1)
It is preferred that the compound be melted at a temperature equal to or higher than the melting point of the compound before being dispersed in advance. Then, a water solvent system as a dispersion medium is similarly heated to a high temperature, and a molten slipping agent is added thereto and finely dispersed by various dispersion methods. Here, the melting point of the general formula (1) is a melting point 50 effective for the scratching property.
When the slipping agent represented by the general formula (1) is used because the temperature is not lower than 200 ° C and not higher than 200 ° C, it is preferable to disperse the water at a temperature of not lower than 50 ° C and lower than 100 ° C.

In the present invention, it is preferable to use a dispersant for dispersion of the general formula (1), and a surfactant is particularly preferable. They are preferably represented by the following general formula (2). General formula (2) Ro-Ao-Xo In the formula, Ro represents a substituted or unsubstituted alkyl group, alkenyl group or aryl group containing at least 10, preferably 12 or more carbon atoms. Ao represents a divalent linking group or a single bond, and Xo represents a water-soluble group.
Ao preferably represents an alkylene group, an arylene group or a composite group thereof, which is a divalent substituted or unsubstituted linking group interrupted by a different atom such as oxygen, ester group, amide group, sulfonyl group, and sulfur. It may be. Preferred specific compounds of these surfactants are shown below, but are not limited thereto.

[0045]

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[0046]

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[0047]

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[0048]

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The surfactant represented by the general formula (2) is preferably added in an amount of 0.1 to 200% by weight, more preferably 0.5 to 100% by weight based on the general formula (1).
%, Particularly preferably 1 to 50% by weight. In dispersing, after mixing the slip agent of the general formula (1) and the dispersant of the general formula (2) together in advance, water or heated hot water may be added, or the slip agent of the general formula (1) may be added. The agent and the dispersant of the general formula (2) may be separately added or dispersed, and there is no particular limitation. The slip agent-dispersed particles can be prepared, for example, by the following procedure. Compound LB-7
(Melting point 90 ° C.) 100 g, p-nonylphenoxypolyoxyethylene (average degree of polymerization 10) 10 g and C ₄₀ H ₈₁ O
10 g of (CH ₂ CH ₂ O) ₁₆ H is added to a 2 liter stainless steel dispersing machine, heated to 100 ° C. and mixed to obtain a viscous mixture. This molten liquid is heated to 95 ° C hot water 80
Add 0g and homogenize at high speed (10,000 rotations, 10 minutes)
Disperse with. Further, the disperser is cooled while the stirring is continued, and the internal temperature is gradually lowered. In this way, it is possible to prepare dispersed particles of the slipping agent having an average particle diameter of 0.14 μm determined by the light diffraction method. Other slip agent-dispersed particles can be prepared by a similar method. In the present invention, the slip property on the image layer side of the heat-developable image recording material obtained by applying the coating solution for the protective layer has a dynamic friction coefficient of 0.25 or less and 0.0 or less.
5 or more, more preferably 0.2 or less 0.05
It is more preferably 0.17 or less and 0.05 or more. The dynamic friction coefficient was evaluated at 25 ° C and 60 ° C.
In a% RH environment, the dynamic friction of a 5-mm diameter stainless steel hard ball with a load of 100 g applied thereto at a speed of 60 mm / sec with the surface of a protective layer containing a slip agent was measured.

Next, in the present invention, a fluorine-containing surfactant is preferably used in a coating solution for a protective layer. Fluorosurfactants are preferably used because of their unique properties.Especially, addition of a small amount lowers the surface tension of the coating solution to provide excellent coating performance and good surface condition. Thus, it can be used for antistatic. The fluorine-containing surfactant preferably used in the present invention is represented by the following general formula (3). Formula (3) Rf-AX wherein Rf is a partially or perfluorinated substituted or unsubstituted alkyl or alkenyl group containing at least 3, preferably 7 or more fluorine atoms, or Represents an aryl group. A represents a divalent linking group or a single bond, and X represents a water-soluble group. A preferably represents an alkylene group, an arylene group or a composite group thereof, which is a divalent substituted or unsubstituted linking group interrupted by a heteroatom such as oxygen, ester group, amide group, sulfonyl group or sulfur. It may be.

X is a hydrophilic group, for example, of the general formula-(BO)
n-R ⁴ polyoxyalkylene group (where B is -CH ₂ CH
_2- , -CH ₂ CH ₂ CH ₂ -or -CH ₂ CH (OH) CH _2- , n represents an average degree of polymerization of a polyoxyalkylene group, and 1 to 50
Is the number of R ⁴ represents a substituted or unsubstituted alkyl group or aryl group), a hydrophilic betaine group, for example,-+ N (R ⁵ ) (R ⁶ ) -AIK-COO-and-+ N
(R ⁵ ) (R ⁶ ) -AIK-SO _3- (wherein AIK represents a lower alkylene group having 1 to 5 carbon atoms, for example, methylene, ethylene, propylene and butylene, and R ⁵ and R ⁶ each independently represent hydrogen. Atom, a substituted or unsubstituted alkyl group, alkenyl group, aralkyl group, aryl group such as a methyl group, an ethyl group, a benzyl group or the like having 1 to 12 carbon atoms and a hydrophilic cation group such as-+ N (R ⁵ ) (R ⁶ ) (R ⁷ ) · Y-(where
R ⁵ , R ⁶ and R ⁷ have the same meanings as R ⁵ described above, and Y − represents an inorganic or organic anion, and is a hydroxy group, a halogen group, a sulfate group, a carbonate group, a perchlorate group, or an organic carboxylic acid group. ,
Organic sulfonic acid group, organic sulfate group, etc.), and preferably a hydrophilic anionic group such as -SO ₃ M, -OSO ₃
M, -COOM, -O-PO (OM) ₂ , -PO (OM) ₂ , -O-PO (OM) (OAR
f), -PO (OM) (OA-Rf) and the like. Here, M represents an inorganic or organic cation, preferably a hydrogen atom, an alkali metal (eg, Li ⁺ , Na ⁺ , K ⁺ ), an alkaline earth metal (eg, Mg ²⁺ , Ca ²⁺ ), and a carbon number of 0. ~ 18 ammonium,
And lower alkylamines. A and Rf are as defined above. Specific examples of typical fluorine-containing surfactants are shown below.

[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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In the present invention, the coating amount of the fluorine-containing surfactant is not more than 250 mg and not more than 0.01 mg per m ² . It is preferably 100 mg or less and 0.1 mg or more, more preferably 50 mg or less and 0.5 mg. The protective layer coating liquid preferably has a pH of 2 or more and 7 or less. In the thermal development, a compound having a low pKa such as phthalic acid or 4-methylphthalic acid is used as a developer, but it is preferable that the compound is present as far as possible from an image forming layer (emulsion layer). Therefore, these acidic substances are preferably added to the coating solution for the protective layer. At that time,
The pH of the coating solution for the protective layer is lowered to generally 4 or less and 2 or more. The neutral region is preferable in consideration of the stability of the latex, but deterioration in photographic performance is observed, and neutral pH cannot be used. Accordingly, the pH of the coating solution for the protective layer is preferably 2 or more and 7 or less, more preferably 2 or more and 5 or less, and particularly preferably 2 or more and 4 or less. As a result, a heat development recording material having excellent heat development activity can be obtained.

The back layer is described below. The total amount of the binder for the back layer is preferably in the range of 0.01 to 15 g / m ² , more preferably 0.05 to 10 g / m ² . A cross-linking agent for cross-linking, a surfactant for improving coating properties, and the like may be added to each layer. Each of these layers may be provided in two or more layers. When the image forming layer has two or more layers, it is preferable to mainly use a polymer latex as a binder for all the layers. The protective layer is a layer provided on the image forming layer and refers to a layer which is not a protective layer when two or more layers are present, and is preferably at least one layer. The back layer is a layer provided on the undercoat layer on the back surface of the support, and there may be two or more layers. However, it is preferable to use a polymer latex for at least one layer, particularly for the back layer of the protective layer.

The Beck smoothness in the present invention can be measured by the Japanese Industrial Standard (JIS) P8119 “Smoothness test method of paper and paperboard using Beck tester” and TAPPI standard method T4.
79 can be easily obtained. The Beck smoothness of at least one of the surface having the image forming layer and the surface of the protective layer opposite to the surface having the image forming layer of the heat-developable image recording material of the present invention is preferably 2000 seconds or less, more preferably 1 second or less.
0 second to 2000 seconds. The Beck smoothness of the surface of the protective layer on the side having the image forming layer of the heat-developable image recording material and the surface of the protective layer on the opposite side are determined by the average particle size of fine particles called a matting agent contained in the layers on both sides and the addition. It can be controlled by varying the amount.
The matting agent is preferably contained in the protective layer which is the protective layer farthest from the support on the side having the image forming layer, and is preferably contained in the protective layer or the back layer which is not the protective layer on the opposite side. .

In the present invention, an antistatic layer comprising a conductive antistatic agent is preferably used. The antistatic agent is not particularly limited, and may be an organic substance or an inorganic compound. In the case of an organic substance, it may be any of an anion, a cation, or a nonion, and may be a low molecular compound or a high molecular compound. In the case of an organic compound, a polymer is preferable. For example, the anionic polymer electrolyte is a polymer containing a carboxylic acid, a salt thereof, and a sulfonate, for example, JP-A-48-22017 and JP-B-46-24159. JP-A-51-30725, JP-A-51-129216, and JP-A-55-129216.
95942. Examples of the cationic polymer include, for example,
JP-A-121523, JP-A-48-91165, and JP-B-49-24582. Ionic surfactants as low molecular compounds also have anionic and cationic properties. For example, JP-A-49-85826 and JP-A-49-33630.
No. 2,992,108, U.S. Pat. No. 3,206,312, JP-A-48-87.
No. 826, JP-B-49-11567, JP-B-49-11568, and JP-A-55-70837.

An antistatic layer made of an inorganic conductive material is very useful, and among them, preferred as an antistatic agent are ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ and In _2.
At least one metal oxide selected from O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , and V ₂ O ₅ or a composite oxide thereof (Sb, P, B, In, S, Si, C), which may be crystalline or sol. Furthermore, conductive carbon particles may be used.
The fine particles of the conductive crystalline or sol-like metal oxide or its composite oxide used in the present invention have a volume resistivity of 10 ⁷ Ω · cm or less, more preferably 10 ³ Ω · cm or less. The shape is not particularly limited, and various shapes such as a sphere, a rod, a needle, a scale, and a plate can be used.
Further, the material may be hollow, and a material such as carbon nanofiber corresponds thereto. Its primary particle size is 0.00001
２2 μm, particularly preferably 0.0001-1 μm. In order to provide conductivity more efficiently, the primary fine particles are partially aggregated (eg, 2 to 10000 aggregates),
It is preferable to use an aggregate of fine particles or fillers of conductive crystalline or sol oxide or a composite oxide thereof having a thickness of 0.01 to 0.5 μm. The relationship between the crystallite size and the particle size of these conductive particles is not particularly limited. When the crystallinity is high, the ratio between the crystallite size and the particle size is 1/1, and the crystallinity is low. In the case of low amorphousness, the ratio can be as high as 1/2000.

Particularly, as the conductive material, a conductive antimony-containing or coated tin oxide fine powder is useful, and these are easily available as commercial products, and include spherical and needle-like materials. Particularly, the acicular conductive antimony-containing tin oxide powder useful therein is described in detail. Although there is no particular limitation on the method of making the pattern, these methods are described in, for example, JP-A-9-12314.
JP-A-8-231222 and JP-A-8-21744
No. 5,8-217444, U.S. Pat.
No. 75957, EP-A-719730, JP-A-56-120519, and JP-A-62-158.
No. 199, and the like. Among them, the acicular conductive antimony-containing or coated tin oxide fine powder preferably used has a minor axis average particle diameter of at least one of 0.005 to 1 μm and a major axis average particle diameter of 0.05 to
It is 10 μm, the aspect ratio is 3 or more, and the specific resistance is 1 kΩ · cm or less, preferably the short-axis average particle diameter is 0.005 to 0.5 μm, more preferably 0.05 to 0.5 μm.
0.5 to 0.2 μm, and the major axis average particle diameter is 0.05 to 0.2 μm.
It is 10 μm, more preferably 0.1-5 μm, and particularly preferably 0.1-3. The aspect ratio of the short axis average particle diameter to the long axis average particle diameter is 3 or more, and preferably 5
More preferably, it is 7 or more. The specific resistance of the acicular conductive antimony-containing tin oxide fine powder is 1 kΩ · cm or less, preferably 500 Ω · cm or less, particularly preferably 100 Ω · cm or less. In order to provide conductivity more efficiently, the primary fine particles are partially aggregated to form 0.05 to 1.
It is preferable to use an agglomerate in the form of a fine powder containing tin oxide or needle-like conductive antimony having a thickness of 0 μm. The ratio of the amount of the acicular conductive antimony-containing or deposited tin oxide fine powder to the binder is preferably from 1/300 to 100/1, more preferably from 1/100 to 100/5. The method of dispersing the spherical or acicular conductive metal fine powder (for example, antimony-containing or coated tin oxide fine powder) in the binder is as follows.
For example, various known means other than JP-A-6-35092 can be used, but a kneader, a pin type mill, an annular type mill and the like are preferable.

In the present invention, the undercoating material is not particularly limited, and examples thereof include gelatin, SBR, and acrylate polymers. Among them, a vinylidene chloride undercoat layer which is preferably used is described. In the heat-developable image recording material, a support coated on both sides with an undercoat layer containing a vinylidene chloride copolymer and having a thickness of 0.3 μm or more (total thickness per one side) is used. Dimensional change can be prevented. The polyester support preferably used in the present invention is subjected to a heat treatment, preferably a heat treatment at a temperature of 130 ° C. or more and 185 ° C. or less after providing an undercoat layer containing vinylidene chloride. The vinylidene chloride copolymer comprises 70 to 99.9% by weight, more preferably 85 to 99% by weight of vinylidene chloride monomer and 0.1 to 5% by weight, more preferably 0.2 to 3% by weight.
It is a copolymer containing a carboxyl group-containing vinyl monomer by weight.

Specific examples of the specific vinylidene chloride material will be given below, but it should not be construed that the invention is limited thereto. V-1 Latex of vinylidene chloride: methyl acrylate: acrylic acid (90: 9: 1) (average molecular weight: 42000) V-2 Vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (8
7: 4: 4: 4: 1) latex (average molecular weight 40,000) V-3 Vinylidene chloride: methyl methacrylate: glycidyl methacrylate: methacrylic acid (90: 6: 2: 2)
Latex (average molecular weight 38000) V-4 Vinylidene chloride: ethyl methacrylate: 2-
Hydroxyethyl methacrylate: latex of acrylic acid (90: 8: 1.5: 0.5) (average molecular weight 44000) V-5 Core / shell type latex (core 90% by weight, shell 10% by weight) Core chloride Vinylidene: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (93:
3: 3: 0.9: 0.1) Shell part Vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (8
8: 3: 3: 3: 3) (Average molecular weight 38000) V-6 Core-shell type latex (core 70% by weight, shell 30% by weight) Core vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (9
2.5: 3: 3: 1: 0.5) Shell part Vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (90: 3: 3: 1: 3) (average molecular weight: 20,000) of vinylidene chloride copolymer layer The thickness is preferably 0.3 μm or more and 4 μm or less, more preferably 0.6 μm or more and 3 μm or less, and still more preferably 1.0 μm or more and 2 μm or less, in order to obtain a good coated surface.

Various supports can be used in the heat-developable image recording material of the present invention. Typical supports are polyethylene terephthalate, polyethylene naphthalate,
Such as polyester, cellulose nitrate, cellulose ester, polyvinyl acetal, and polycarbonate. Among them, biaxially stretched polyester, especially polyethylene terephthalate (PET) has strength, dimensional stability,
It is preferable from the viewpoint of chemical resistance and the like. The thickness of the support is preferably 60 to 200 μm as a base thickness excluding the undercoat layer. The support used in the heat-developable image recording material of the present invention is used for reducing the internal strain remaining in the film during biaxial stretching and eliminating the heat shrinkage distortion generated during the heat development.
Polyester, particularly polyethylene terephthalate, which has been subjected to a heat treatment in a temperature range of 30 to 185 ° C is preferably used. Such a thermal relaxation treatment may be performed at a constant temperature within the temperature range, or may be performed while increasing the temperature.

The heat treatment of the support may be performed in the form of a roll, or may be performed while transporting the support in the form of a web. In the case where the transfer is carried out in the form of a web, the transfer tension of the support during the heat treatment is preferably relatively low, and specifically, 7 kg /
cm ² or less, particularly preferably to 4.2 kg / cm ² or less. The lower limit of the transport tension at this time is not particularly limited, but is about 0.5 kg / cm ² . Such a heat treatment is preferably performed after a treatment for improving the adhesiveness of the image forming layer and the back layer to the support, an undercoating layer containing a vinylidene chloride copolymer, and the like are applied. The heat shrinkage of the support after heating at 120 ° C. for 30 seconds is preferably −0.03% to + 0.01% in the machine direction (MD) and 0 to 0.04% in the transverse direction (TD). . The support may include a vinylidene chloride copolymer layer if necessary,
An undercoat layer using BR, polyester, gelatin or the like as a binder may be applied. These undercoat layers may have a multilayer structure, or may be provided on one side or both sides of the support. At least one of these undercoat layers can be a conductive layer. The general thickness (per layer) of the undercoat layer is 0.01 to 5 μm, more preferably 0.05 to 1 μm.
μm. There is no problem that the undercoat layer also serves as the above-mentioned conductive layer.

In the present invention, the exposure apparatus used for imagewise exposure may be any apparatus capable of performing exposure with an exposure time of less than 10 ^-7 seconds.
D), an exposure apparatus using a Light Emitting Diode (LED) as a light source is preferably used. In particular, LD is more preferable in terms of high output and high resolution. Any of these light sources may be used as long as it can generate light of an electromagnetic wave spectrum in a target wavelength range. For example, for LD,
Dye lasers, gas lasers, solid-state lasers, semiconductor lasers, and the like can be used. The exposure is performed by overlapping the light beams of the light source, and the overlap means that the sub-scanning pitch width is smaller than the beam diameter. For example, the overlap can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient) when the beam diameter is expressed by a half width of beam intensity (FWHM). In the present invention, the overlap coefficient is preferably 0.2 or more. The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a plane scanning method, or the like can be used.
The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface type, a multi-channel is preferably used.

The heat-developable image recording material of the present invention has a low haze upon exposure and tends to cause interference fringes. Examples of this interference fringe prevention technology include a technology for obliquely entering a laser beam into a photosensitive material, which is disclosed in Japanese Patent Application Laid-Open No. 5-113548, and a technology disclosed in International Patent Publication WO95 / 31754. There are known methods using a multimode laser, and it is preferable to use these techniques.
In the heat development step of the image forming method, development may be performed by any method, but usually development is performed by raising the temperature of the photosensitive material exposed imagewise. A preferred embodiment of the heat developing machine used is a type in which the heat-developable image recording material is brought into contact with a heat source such as a heat roller or a heat drum.
No. 5-56499, Patent No. 684453, JP-A-9-29269
No. 5, JP-A-9-297385 and International Patent WO95 /
Japanese Patent Application Laid-Open No. 7-13294, International Patent WO 97/28489, Japanese Patent Application 97/28488 and Japanese Patent Application Laid-Open No. There is a machine. A particularly preferred embodiment is a non-contact type thermal developing machine. Preferred development temperature is 80 to 250 ° C
And more preferably 100 to 140 ° C. The development time is preferably from 1 to 180 seconds, more preferably from 5 to 90 seconds. As a method for preventing processing unevenness due to dimensional change during heat development of the heat-developable image recording material of the present invention, 80 ° C or more 115 ° C
A method in which an image is formed at a temperature of less than 3 seconds and heated for 3 seconds or more and then thermally developed at 110 ° C. to 140 ° C. to form an image (a so-called multi-stage heating method) is effective.

FIG. 1 shows an example of the configuration of a heat developing machine used for the heat development of the heat-developable image recording material of the present invention. FIG. 1 is a side view of the heat developing machine. The heat developing machine shown in FIG. 1 carries a pair of carry-in rollers 11 (a lower roller is a heat roller) for carrying the heat-developable image recording material 10 into a heating section while correcting and preheating the heat-developable image recording material 10 in a plane, and heat development after heat development after heat development. It has an unloading roller pair 12 that unloads the image recording material 10 from the heating unit while correcting it into a flat shape. The heat-developable image recording material 10 is moved from the carry-in roller pair 11 to the carry-out roller pair
Developed while transported to In the conveying means for conveying the heat-developable image recording material 10 during the heat development, a plurality of rollers 13 are provided on the side in contact with the surface having the image forming layer, and the non-woven fabric ( For example, a smooth surface 14 on which polyphenylene sulphite or Teflon is adhered is provided. The back surface of the heat-developable image recording material 10 is smoothed by driving a plurality of rollers 13 in contact with the surface having the image forming layer.
4 and is transported. As the heating means, a heater 15 is provided at an upper portion of the roller 13 and a lower portion of the smooth surface 14 so as to be heated from both sides of the heat-developable image recording material 10. As a heating means in this case, a plate heater or the like can be used. Although the clearance between the roller 13 and the smooth surface 14 differs depending on the member of the smooth surface, the heat-developable image recording material 10
Is appropriately adjusted to a clearance that can be conveyed. Preferably it is 0 to 1 mm.

The material of the surface of the roller 13 and the smooth surface 14
Is a high-temperature durable, heat-developable image recording material 10
Any material may be used as long as it does not hinder the conveyance of the roller. However, the material of the roller surface is preferably silicon rubber, and the member having a smooth surface is preferably a nonwoven fabric made of aromatic polyamide or Teflon (PTFE). It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely. The pre-heating section upstream of the heat development processing section has a temperature and time lower than the heat development temperature (for example, about 10 to 20 ° C.) and sufficient for evaporating the water content in the heat development image recording material. The temperature is preferably set to a temperature higher than the glass transition temperature (Tg) of the support of the heat-developable image recording material 10 so that development unevenness does not occur. Further, a guide plate 16 is provided downstream of the thermal development processing section, and a slow cooling section is further provided. The guide plate is preferably made of a material having low thermal conductivity, and is preferably cooled gradually. As described above, the description has been given according to the illustrated example, but is not limited thereto.
The heat developing machine used in the present invention, such as that described in Japanese Patent Publication No. 294, may have various configurations. In the case of the multi-stage heating method preferably used in the present invention, in the above-described apparatus, two or more heat sources having different heating temperatures may be provided, and heating may be performed continuously at different temperatures.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The following materials, amount used,
The ratio, operation, and the like can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

[Example] <Example 1> 1. Preparation of silver halide emulsion 1-1) Emulsion A 11 g of alkali-treated gelatin (2700 ppm or less as calcium content), 30 mg of potassium bromide, and 10 mg of sodium benzenethiosulfonate were dissolved in 700 ml of water, and the pH was adjusted at 40 ° C. After adjusting to 5.0, an aqueous solution containing 18.6 g of silver nitrate 159 m
l and potassium bromide at 1 mol / l (NH ₄ ) ₂ RhCl
₅ (H ₂ O) at 5 × 10 ⁻⁶ mol / liter and K ₃ IrCl ₆
While maintaining an aqueous solution containing 2 × 10 ⁻⁵ mol / l at pAg 7.7 by a control double jet method over 6 minutes and 30 seconds. Then, 476 ml of an aqueous solution containing 55.5 g of silver nitrate, 1 mol / l of potassium bromide and 2 × of K ₃ IrCl ₆ were added.
10 ^- was added over 28 minutes 30 seconds at ⁵ mol / liter controlled double jet method while maintaining the pAg7.7 a halogen salt aqueous solution containing. Thereafter, the pH was lowered to cause coagulation and sedimentation, followed by desalting treatment. 0.17 g of compound A, low molecular weight gelatin having an average molecular weight of 15,000 (calcium content: 20 ppm or less) 5
1.1 g was added to adjust the pH to 5.9 and pAg 8.0. The obtained particles were cubic particles having an average particle size of 0.08 μm, a projected area variation coefficient of 9%, and a (100) plane ratio of 90%. The silver halide grains thus obtained were heated to 60 ° C., and 76 μmol of sodium benzenethiosulfonate was added per 1 mol of silver, and 3 minutes later, 71 μmol of triethylthiourea was added, followed by aging for 100 minutes.
After adding 5 × 10 ⁻⁴ mol of -hydroxy-6-methyl-1,3,3a, 7-tetrazaindene, the temperature was lowered to 40 ° C. Thereafter, the temperature was maintained at 40 ° C., and 12.8 × 10 ⁻⁴ mol of the following sensitizing dye A and 6.4 × 10 ⁻³ mol of compound B were added to 1 mol of silver halide with stirring. The mixture was rapidly cooled to ℃ to complete the preparation of silver halide emulsion A. Immediately before coating, the obtained emulsion A was heated to 40 ° C. to dissolve it, and the filtration was examined using a Fujifilm microfilter PPF.
In order to fix the filter during filtration, a filter cartridge FS manufactured by Fuji Photo Film Co., Ltd. was used.
1-1 was used.

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1-2) Preparation of Organic Acid Silver Dispersion <Organic Acid Silver A> Behenic acid manufactured by Henkel (product name Eden)
or C22-85R) 87.6 g, distilled water 423 ml, 5N-NaOH aqueous solution 49.
2 ml, tert-butyl alcohol 120 ml mixed, at 75 ℃
The mixture was stirred and reacted for 1 hour to obtain a sodium behenate solution. Separately, prepare 206.2 ml of an aqueous solution of 40.4 g of silver nitrate,
Was kept warm. The reaction vessel containing 635 ml of distilled water and 30 ml of tert-butyl alcohol was kept at 30 ° C., and while stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were kept at a constant flow rate for 62 minutes 10 seconds and 60 minutes, respectively. Added over minutes. At this time, only the silver nitrate aqueous solution was added for 7 minutes and 20 seconds after the start of the silver nitrate aqueous solution addition, and then the sodium behenate solution was started to be added.
For 9 minutes and 30 seconds, only the sodium behenate solution was added. At this time, the temperature in the reaction vessel was 30 ° C,
The liquid temperature was controlled so as not to rise. In addition, the piping of the addition system for the sodium behenate solution was kept warm by steam tracing, and the liquid temperature at the outlet of the addition nozzle tip was 75%.
The steam amount was controlled so as to reach ℃. Also,
The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double tube. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After completion of the addition of the sodium behenate solution, the mixture was left to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid thus obtained was stored as a wet cake without drying. When the morphology of the obtained silver behenate particles was evaluated by electron micrographing, the average projected area diameter was 0.52 μm,
It was a flaky crystal having an average particle thickness of 0.14 μm and a variation coefficient of the average equivalent sphere diameter of 15%.

Next, a dispersion of silver behenate was prepared by the following method. To a wet cake having a dry solid content of 100 g, 7.4 g of polyvinyl alcohol (trade name: PVA-217, average degree of polymerization: about 1700, filtered with a 3 μm pore size filter) and water are added, and the total amount is adjusted to 385 g. Pre-dispersed with a mixer. Next, the pre-dispersed stock solution is
(Product name: Microfluidizer M-110S-E
H, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) at a pressure of 1750 kg / cm ² and treated three times to obtain a silver behenate dispersion. For cooling operation, install a coiled heat exchanger before and after the interaction chamber, respectively.
The desired dispersion temperature was set by adjusting the temperature of the refrigerant. The silver behenate particles contained in the silver behenate dispersion thus obtained were particles having a volume-weighted average diameter of 0.52 μm and a coefficient of variation of 15%. Particle size measurements are available from Malvern Instruments Lt.
d. Performed with MasterSizerX. When evaluated by electron microscopy, the ratio of the long side to the short side was 1.5, and the particle thickness was 0.14μ.
m, and the average aspect ratio (ratio of the equivalent circle diameter of the projected area of the grain to the grain thickness) was 5.1. Filtration of the obtained silver behenate dispersion was examined using Fujifilm Microfilter PPF. In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used.

1-3) Preparation of solid dispersion of reducing agent (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane) 1,1-bis (2- (Hydroxy-3,5-dimethylphenyl) -3,5,5-
To 25 g of trimethylhexane, 25 g of a 20% aqueous solution of MP-203 manufactured by Kuraray Co., Ltd., 0.1 g of Safinol 104E manufactured by Nissin Chemical Co., Ltd., 2 g of methanol and 48 ml of water were added and stirred well. The slurry was left for 3 hours. Then 1
360 g of zirconia beads having a diameter of 360 mm were prepared and put into a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) for 3 hours to prepare a solid dispersion of a reducing agent. Particle size, 80% by weight of particles is 0.3 μm
It was 1.0 μm or less. Filtration of the obtained reducing agent solid dispersion was examined using a Fujifilm microfilter PPF. In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used.

1-4) Preparation of solid dispersion of polyhalogen compound To 30 g of polyhalogen compound-A, 4 g of MP-203 of Kuraray Co., Ltd., 0.25 g of compound C and 66 g of water were added. Stir well, then prepare 200g of 0.5mm zirconia silicate beads, put in a vessel together with the slurry, disperse with a disperser (1 / 16G sand grinder mill: manufactured by Imex Co., Ltd.) for 5 hours, and disperse the solid Was prepared. As for the particle diameter, 80% by weight of the particles were 0.3 μm or more and 1.0 μm or less. Filtration of the obtained solid dispersion of the polyhalogen compound-A was examined using a Fujifilm microfilter PPF. In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used. Polyhalogen compound-
For B, a solid dispersion was prepared in the same manner as for the polyhalogen compound-A, and had the same particle diameter. Filtration of the obtained polyhalogen compound-B dispersion was examined using a Fujifilm microfilter PPF. In order to fix the filter during filtration, Fuji Photo Film Co., Ltd.
The filter cartridge FS1-1 manufactured by Toshiba was used.

1-5) Preparation of solid dispersion of nucleating agent To 10 g of compound AA as a nucleating agent, 2.5 g of polyvinyl alcohol (PVA-217 manufactured by Kuraray) and 87.5 g of water were added, and the mixture was stirred well to form a slurry. Left for 3 hours. Then 0.5mm
Prepare 240g of zirconia beads in a vessel together with the slurry and place in a vessel (1 / 4G sand grinder mill:
The mixture was dispersed for 10 hours using IMEX Co., Ltd. to prepare a solid dispersion. Particle size, 80% by weight of the particles is 0.1 μm or more 1.
It was 0 μm or less and the average particle size was 0.5 μm. Filtration of the obtained nucleating agent dispersion liquid was examined using a Fujifilm microfilter PPF. In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used.

1-6) Preparation of Solid Dispersion of Compound Z To 30 g of Compound Z, 3 g of MP-203 (manufactured by Kuraray Co., Ltd.) and 87 ml of water were added, and the mixture was thoroughly stirred to obtain a slurry. Left for hours. Thereafter, a solid dispersion of the compound Z was prepared in the same manner as in the preparation of the solid dispersion of the reducing agent. As for the particle diameter, 80 wt% of the particles were 0.3 μm or more and 1.0 μm or less. Filtration of the obtained dispersion of the compound Z was examined using a Fujifilm microfilter PPF. In order to fix the filter during filtration, a filter cartridge FS1 manufactured by Fuji Photo Film Co., Ltd. was used.
-1 was used.

1-7) Preparation of Image Forming Layer Coating Solution The following binder, material, and silver halide emulsion A were added to 1 mol of silver of the organic acid silver microcrystal dispersion prepared above. Water was added to obtain an image forming layer coating solution. The viscosity was 20-70 cp (25 ° C.) and the pH was 7.4. The obtained coating solution for the image forming layer was used as it was without filtration, or Fujifilm Micro Filter PPF03 (3 μm) was used as the additive material in the above items 1-1) to 1-6). Further, the other additional materials were similarly subjected to filtration by using Fujifilm Micro Filter PPF03 (3 μm) as necessary. Note that a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used to fix the filter in the filtration. Binder: Luckstar 3307B 397 g as solids (manufactured by Dainippon Ink and Chemicals, Incorporated; glass transition temperature of 17 ° C. with SBR latex), which was previously filtered using a Fujifilm microfilter PPF03 (pore size: 3 μm) immediately before preparation.・ Reducing agent (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane) 149 g as solids ・ Polyhalogen compound-A 34.8 g as solids ・ Polyhalogen Compound-B 9.0 g as solid content-0.30 g as sodium ethyl thiosulfonate (5% aqueous solution)-1.04 g as benzotriazole (5% methanol solution)-polyvinyl alcohol (PVA manufactured by Kuraray Co., Ltd.) -235) (5% aqueous solution) 10.8 g as solids ・ 6-iso-propylphthalazine (5% methanol solution) 15.0 g as solids ・ Sodium dihydrogen orthophosphate dihydrate ( (5% aqueous solution) 0.37 g as solid content ・ Compound Z 9.7 g as solid content ・ Nucleating agent Compound AA 5.0 g ・ Dye A Coating amount which gives an optical density of 783 nm of 0.3 (0.37 g as a guide) ・ Silver halide emulsion A (5% methanol solution) 0.06 mol of Ag

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[0082] 2. Preparation of coating solution for lower protective layer on image forming layer
Ltd. of methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2 Glass transition temperature 57 ° C. at a polymer latex solution (copolymer (wt%), solid 21.5% as the concentration, of H ₂ O was added to 15 wt% containing) 956G compound D with respect to the solid content of the latex as coalescent, compound E-1 0.81, compound E-2 0.81 g compound S 1.62 g, 1.98 g of matting agent (polystyrene particles, average particle size 7 μm) and 23.6 g of polyvinyl alcohol (Kuraray Co., Ltd., PVA-235, 5% aqueous solution) were added, and further added.
H2O was added to prepare 1 liter of a coating solution. Viscosity 2
It was 0-70 cp (25 ° C) and the pH was 5.4. Fujifilm micro filter PPF10 (pore size 1
(0 μm). In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used.

[0083] 3. Preparation of coating solution for upper protective layer on image forming layer
Ltd. of methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2 Glass transition temperature 54 ° C. at a polymer latex solution (copolymer (wt%), solid 21.5% as the concentration, 15 wt% containing compound D with respect to the solid content of the latex as coalescent) of H ₂ O was added to 630 g, 1.44 g of lubricant dispersed particles 10 wt% solution described in the text,
0.36 g of compound E-1, 0.36 g of compound E-2,
0.72 g of compound E-3, 7.95 g of compound F, 72 g of compound S, 1.18 g of a matting agent (polystyrene particles, average particle size 7 μm) and polyvinyl alcohol (Kuraray
8.30 g of a PVA-235 (5% aqueous solution, manufactured by Co., Ltd.) was added, and H ₂ O was added to prepare 1 liter of a coating solution. Viscosity is 20-70 cp
(25 ° C.) and the pH was 2.9. The surface tension was between 25 and 28 dynes / cm. Filtration was performed using Fujifilm Micro Filter PPF10 (10 μm). In order to fix the filter in the filtration, a filter cartridge FS1-1 manufactured by Fuji Photo Film Co., Ltd. was used.

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[0085] 4. PET support with backing / priming layer
Preparation of 4-1) Support Using terephthalic acid and ethylene glycol, a PET having an IV (intrinsic viscosity) of 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (weight ratio)) was obtained according to a conventional method. Obtained. After pelletizing this, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and quenched,
An unstretched film having a thickness of 120 μm after heat setting was prepared. Using rolls with different peripheral speeds,
The film was longitudinally stretched 3.3 times and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck part of the tenter, knurling is performed on both ends, and 4.8 kg / cm ²
Rolled up. In this way, width 2.4m, length 3500m,
A roll having a thickness of 120 μm was obtained.

4-2) Undercoat layer (a) Polymer latex (1) (core-shell type latex having a core of 90% by weight and a shell of 10% by weight, core: vinylidene chloride / methyl acrylate / methyl methacrylate / Acrylonitrile / acrylic acid = 93/3/3 / 0.9 / 0.1 (% by weight), shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3/3 (% by weight) the weight average molecular weight 38000 of the polymer latex) in 3.0g / m ² · 2,4- dichloro-6-hydroxy -s- triazine 23 mg / m ² · matting agent solid basis embodying the undercoat consisting of (polystyrene, mean particle size 2.4 μm) 1.5 mg / m ^{2 The} obtained coating solution was filtered using a profile filter (pore size: 5 μm) immediately before coating.

4-3) Undercoat layer (b) Deionized gelatin (Ca ²⁺ content 0.6 ppm, jelly strength 230 g) 50 mg / m
^{(2) The} prepared coating solution was filtered using Fujifilm Micro Filter PPF03 (pore size: 3 μm) immediately before coating.

4-4) Conductive layer ・ Julima ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) 96 mg / m ²・ Alkali-treated gelatin (molecular weight about 10,000, Ca ²⁺ content 30 ppm) 42 mg / m ²・ Deionization treatment Gelatin (Ca ²⁺ content 0.6 ppm) 8 mg / m ² · Compound A 0.2 mg / m ² · Poly (degree of polymerization 12) oxyethylene nonylphenyl ether 10 mg / m ² · Sumitex Resin M-3 (water-soluble melamine compound, 18 mg / m ² · Dye A Coating amount at which the optical density of 783 nm becomes 1.2 · SnO ₂ / Sb ₂ O ₃ (9/1 weight ratio, needle-like fine particles, major axis / minor axis = 20-30, Ishihara Sangyo Co., Ltd. FP10) 160 mg / m ² · Matting agent (cross-linked polymethyl methacrylate, average particle size 5 μm) 7 mg / m ^{2 The} obtained coating solution was filtered using Fujifilm Micro Filter PPF10 (pore size 10 μm) immediately before coating.

4-5) Back protective layer Polymer latex- (2) (methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1 (% by weight) Copolymer)) 1000 mg / m ^{2 in} solid content, polystyrene sulfonate (molecular weight: 1,000 to 5,000) 2.6 mg / m ² · sodium cetyl sulfate 10 mg / m ² · cellosol 524 (Carnauba wax, Chukyo Yushi Co., Ltd.) 15 mg / m ² · Sumitex Resin M-3 The obtained coating solution for the polyhalogen back protective layer was filtered using a Fujifilm Micro Filter PPF03 (pore size: 3 μm) immediately before coating. (Water-soluble melamine compound, manufactured by Sumitomo Chemical Co., Ltd.) 218 mg / m ²

4-6) PET with Back / Undercoat Layer
Preparation of Support An undercoat layer (a) and an undercoat layer (b) were sequentially applied to both surfaces of the support (base), and each was dried at 180 ° C for 4 minutes. Next, the undercoat layer (a) and the undercoat layer (b) were applied, and a conductive layer and a protective layer were sequentially applied to one surface on one side.
After drying for minutes, a PET support with a back / subbing layer was prepared. The dry thickness of the undercoat layer (a) was 2.0 μm. In preparing each coating layer, each coating liquid was passed through an ultrasonic defoaming machine immediately before coating in order to sufficiently remove bubbles existing in the liquid, and the bubbles were removed.

[0091] 5. Transport Heat Treatment 5-1) Heat Treatment The prepared PET support with the back / undercoat layer was placed in a heat treatment zone having a total length of 200 m set at 160 ° C., and was transported at a tension of 3 kg / cm ² and a transport speed of 20 m / min. 5-2) Post-heat treatment After the above heat treatment, post-heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and the film was wound. The winding tension at this time is 10
kg / cm ² .

[0092]

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[0093] 6. Preparation of heat-developable image recording material The above-described undercoat layer (a) and the undercoat layer (b) were coated on the undercoat layer of the PET support on which the undercoat layer (b) was coated.
It was applied so as to be 1.7 g / m ² . Further, the coating solution for the lower protective layer on the image forming surface was simultaneously coated with the coating solution for the image forming layer such that the solid content of the polymer latex was 1.31 g / m ² . Thereafter, the coating solution for the upper protective layer of the image forming layer was applied thereon so that the applied amount of the solid content of the polymer latex was 3.02 g / m ² , thereby producing a heat-developable image recording material. In addition, in producing each coating layer, each coating solution is to sufficiently remove bubbles present in the solution,
It was passed through an ultrasonic defoaming machine immediately before coating to remove bubbles. The film surface pH on the image forming side of the obtained heat-developable image recording material was 4.
9. The Beck smoothness was in the range of 400 to 900 seconds, the pH of the opposite film surface was 5.9, and the Beck smoothness was 560.

[0094] 7. Heat development 7-1) Exposure treatment The resulting heat-developable image recording material was subjected to a single-channel cylindrical inner surface equipped with a semiconductor laser having a beam diameter (FWHM of 1/2 the beam intensity) of 12.56 μm, a laser output of 50 mW, and an output wavelength of 783 nm. The exposure time was adjusted by changing the number of rotations of the mirror, and the exposure amount was changed by changing the output value, and exposure was performed at 2 × 10 ⁻⁸ seconds using a laser exposure apparatus of the system. The overlap coefficient at this time was set to 0.449. 7-2) Heat development treatment The exposed heat-developable image recording material was heated using a heat-development machine shown in FIG.
Smooth surface is made of Teflon non-woven fabric.
The heat development processing was performed at 120 ° C. for 25 seconds for 25 seconds.
The temperature accuracy in the width direction was ± 1 ° C.

[0095] 8. Evaluation 8-1) Filtration property of the coating solution for the image forming layer The prepared coating solution for the image forming layer was subjected to a filtration test with a Fuji Photo Film Microfilter PPF03 (pore size: 3 μm), and the increase in the filtration pressure was measured as follows. evaluated. At this time, the liquid sending amount was A: no increase in filtration pressure was observed. B: A slight increase in filtration pressure was observed. C: A considerable increase in filtration pressure was observed. D: Filtration pressure rise was remarkably poor, and filtration was difficult. 8-2) Evaluation of Streaks The surface of the coated photosensitive material was visually observed to evaluate streaky unevenness. The evaluation was classified as follows. A: No coating streak is observed. B: Some coating streaks are observed. C: Applied streaks are considerably recognized. D: The coating streak is observed on the entire surface.

8-3) Evaluation of Coated Repelling The surface of the coated photosensitive material was visually observed to evaluate repelling defects (circular). The evaluation was classified as follows. A: No repelling is observed. B: The coating repelling was slightly recognized, but the size was small. C: The coating repelling was considerably recognized and the size was large. D: Repelling was observed on the entire surface, and the size was extremely large. 8-4) Evaluation of Pinhole A sample (size: 60 cm × 75 cm) was heated using a heat developing machine shown in FIG. Developed. The temperature accuracy in the width direction was set at ± 1 ° C. The heat-developed sample was transmitted through a high-intensity Shark Sten, and a pinhole was visually observed and evaluated as follows. A: No pinhole is observed. B: Pinholes are slightly observed. C: Pinholes are considerably recognized. D: Many pinholes are recognized and the size is large.

8-5) Evaluation of unevenness in thermal development Using a thermal developing machine shown in FIG. 1, a sample (size: 60 cm × 75 cm) was thermally developed under the above-mentioned conditions, and wrinkles of the sample during processing were evaluated. The occurrence was visually observed. The evaluation was classified as follows. A: No unevenness in thermal development is observed. B: Heat development unevenness is slightly observed. C: Thermal development unevenness is considerably recognized. 8-6) Scratches A sample (size: 60 cm × 75 cm) was heat-developed under the above-mentioned conditions using the heat developing machine shown in FIG. 1, and the level of occurrence of scratches on the image side after the processing was visually observed. The evaluation was classified as follows. A: Almost no damage is observed after thermal development, and there is no actual harm on the print. B: Slight damage after thermal development is observed, and it appears on the print. C: Damage after thermal development is considerably recognized, and irreparable harm occurs on the print.

8-7) Evaluation with dust The obtained sample was heat-treated at 120 ° C. for 25 seconds in the entire exposed state to obtain a blackened sample. This sample was placed at 25 ° C, 10
The humidity was adjusted for 2 hours under the condition of% RH, the back surface and the emulsion surface were overlapped, and rubbed 10 times with an excessive weight of 1 kg / cm ² . Pulverized polystyrene pieces were scattered on the emulsion surface, and the degree of adhesion was visually observed. A: No adhesion of polystyrene pieces was observed. B: Some polystyrene fragments are observed. C: Polystyrene pieces are considerably recognized. 8-8) Conductivity The obtained raw sample was conditioned at 25 ° C. and 10% RH for 2 hours, silver paint was applied to the side surface, and the electric resistance (Ω) of the sample was measured.

8-9) Method of Measuring Dimensional Change Rate Due to Heat Development Processing Two holes each having a diameter of 8 mm were formed at intervals of 200 mm on a sample (size 5 cm × 25 cm) which had been exposed to light over its entire surface.
The distance between the two holes was accurately measured using a pin gauge with a precision of / 1000 mm. The dimension at this time is defined as X (unit: mm). Then, using the heat developing machine shown in FIG.
After the heat development processing under the developing condition of second, the dimensions 120 minutes later were measured with a pin gauge. The dimension at this time is Y (unit: m
m). The dimensional change rate was evaluated by a value obtained by the following formula. This is an evaluation value in the horizontal direction of the base. Dimensional change rate (%) = [(Y−X) / 200] × 100

8-10) Evaluation Results The characteristics of the obtained samples 01 to 08 were evaluated. As is clear from Table 1, Samples 02 to 06 of the present invention had good filterability of the coating solution for the image forming layer and satisfied all of the coating streaks, the coating repellency, and the pinholes. Further, the sample of the present invention is excellent in all ranks A in heat development unevenness, scratching, and dusting, and has a resistance of 10%.
Of the eighth power (Ω). In addition, the dynamic friction coefficients are all 0.
11 or less, which was excellent characteristics. Further, the dimensional change rate due to the heat development treatment was 0.009%, which was small and good. On the other hand, Comparative Sample 01, which does not filter the additional material for the image forming layer at all, has a level at which the filterability of the coating solution for the image forming layer is extremely poor and cannot be substantially produced, and a coating streak,
All of the repelling and pinholes were very bad. Further, Comparative Samples 07 and 08 in which the amount of filtration of the additive material for the image forming layer was less than 50% by weight had insufficient filterability of the coating solution of the image forming layer, and poor coating streaks, coating cissing and pinholes. It was a problem as a product. In addition, all the filtration filters used for filtering the additive material for the image forming layer of Sample 04 were Fujifilm microfiltration filters PPE01 (1 μm).
An attempt was made to prepare an aqueous coating solution for an image forming layer instead of m) (Sample 041). However, clogging occurred immediately after filtration, and an aqueous coating solution for an image forming layer could not be prepared. From the above, it is apparent that a problem occurs if the pore size of the filter for filtering the additive material for the image forming layer is too small. From the above, it is apparent that the present invention can provide an extremely excellent heat-developable image recording material, which is prepared by filtering an additive material through a filter having a specific pore size when preparing an aqueous coating solution for an image forming layer. It is because of that.

[0101]

[Table 1]

Example 2 Sample 03 of the present invention of Example 1
Example 1 was repeated except that the coating solution for the image forming layer, the coating solution for the lower protective layer on the image forming surface, and the coating solution for the upper protective layer on the image forming layer were simultaneously extruded in this order in the preparation of the heat-developable image recording material. A sample 23 was obtained in exactly the same manner as described above. This sample satisfied all of the coating streak, the coating repelling, and the pinhole. From the above, it is clear that the characteristics of the present invention do not change in any of the divided coating and the simultaneous multi-layer coating.

<Example 3> Sample 03 of the present invention of Example 1
In Example 1, except that the coating solution for the image forming layer was further filtered with a Fujifilm microfilter FFP10
A sample 33 was obtained in exactly the same manner as described above. The coating streak, coating repellency, and pinhole were all at the A level, and the image was observed at a magnification of 10 times. As a result, it was confirmed that the fine pinholes were further reduced as compared with Sample 01, and the sample was excellent. From the above, it is clear that in the present invention, it is preferable to further filter after preparing the coating solution for the image forming layer.

<Example 4> Sample 03 of the present invention of Example 1
In Example 1, except that the coating solution for the image forming layer was not subjected to ultrasonic defoaming, but was allowed to stand for a short time after the preparation, and then applied.
A sample 43 was obtained in exactly the same manner as described above. Although the sample 43 was acceptable as a commercial product, the coating streaks, the coating repelling and the pinholes were all at the B level, and deterioration was observed. From the above, it is clear that in the present invention, the defoaming treatment of the coating solution for the image forming layer is preferable.

<Example 5> Sample 03 of the present invention of Example 1
, A sample 53 was obtained in exactly the same manner as in Example 1 except that the slip agent-dispersed fine particles added to the outermost layer coating solution on the image layer side were excluded. This sample 53 satisfied all of the coating streak, the coating repelling, and the pinhole. However, heat development unevenness was slightly observed, and the slip characteristic was reduced to 0.30, but no serious problem occurred in practical use. From the above, it is clear that in the present invention, it is preferable to contain fine particles dispersed with a slip agent.

Example 6 Sample 03 of the present invention of Example 1
A sample 63 was obtained in exactly the same manner as in Example 1 except that the fluorine-based surfactants (compounds E-1 and E-2) added to the protective layer coating solution on the image forming layer side were removed. At this time, the surface tension of the protective layer coating solution was 33 dynes / cm. These samples were evaluated in exactly the same manner as in Example 1. As a result, there was no actual harm, but the initial application was slightly unstable when the application speed was increased to 120 m / min. On the other hand, the coating liquid of Sample 07, which is a preferred embodiment of the present invention, had a surface tension of 26 dynes / cm, formed stable ghee beads even at high-speed coating, and had a stable coating. From these results, it is apparent that the addition of a fluorine-based surfactant is effective in desirably exhibiting the desired effects of the present invention.

<Example 7> Sample 03 of the present invention of Example 1
Example 1 was the same as Example 1 except that the acicular conductive antimony-containing tin oxide fine powder of the conductive layer on the back side of the image layer was removed.
A sample 73 was obtained in exactly the same manner as described above. While the conductivity of sample 03 is 10 ⁸ Ω, the conductivity of sample 73 is 10 ⁸ Ω.
¹⁵ Ω, and the conductivity was deactivated. These samples were evaluated exactly as in Example 1. As a result, it was confirmed that, although there was no actual harm, the surface was slightly uneven when observed in detail by reflection. On the other hand, in the case of the coating liquid of Sample 03, which is a preferred embodiment of the present invention, these unevenness was not observed at all, and an excellent image could be obtained. From these results, it is clear that it is effective to provide a conductive layer in order to desirably exhibit the desired effects of the present invention.

[0108]

According to the present invention, it has been clarified that coating streaks, coating repelling, and pinholes are improved, and that unevenness and damage during thermal development can be significantly reduced. Further, a dimensional change with time after thermal development can be reduced. Further, an excellent heat-developable image material free from dust can be produced.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration example of a heat developing machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 heat-developed image recording material 11 carry-in roller pair 12 carry-out roller pair 13 roller 14 smooth surface 15 heating heater 16 guide plate A preheating section B heat development processing section C slow cooling section

Claims (4)

[Claims] 1. A heat-developable image recording material having an image-forming layer on at least one of its supports and subjected to a heat-development treatment at a development temperature of 80 ° C. or more and 140 ° C. or less, comprising: The aqueous coating solution for an image forming layer is formed by adding at least 50% by weight (in terms of dry solid content) or more of the additive material for an image forming layer to 2 μm or more and 30 μm or more.
m. Image recording material. 2. The heat-developable image recording material according to claim 1, wherein the aqueous coating solution for image formation is filtered with a filter having a pore size of 2 μm or more and 30 μm or less before coating. 3. The heat-developable image recording material according to claim 1, wherein the aqueous coating solution for the image forming layer is defoamed before coating. 4. A method for producing a heat-developable image recording material having an image-forming layer on at least one of the supports and performing a heat-development process at a developing temperature of 80 ° C. or more and 140 ° C. or less, comprising: The aqueous coating solution for an image forming layer composed of an additive material is coated with at least 50% by weight (in terms of dry solid content) or more of the additive material for an image forming layer in an amount of 2 μm or more and 30 μm or more.
m, which is prepared by adding a latex to a latex after filtration through a filtration filter having a pore size of not more than m, and applying and drying the prepared aqueous coating solution for image formation to form the image forming layer. A method for producing a heat-developable image recording material.