JP2006301499A - Silver salt photothermographic dry imaging material, image recording method and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silver salt photothermographic dry imaging material having low fog, high density and excellent storage stability and ensuring little density unevenness, and to provide an image recording method and an image forming method using the same. <P>SOLUTION: The silver salt photothermographic dry imaging material is obtained by disposing on a support a photosensitive layer containing a photosensitive silver halide emulsion containing non-photosensitive silver salt of aliphatic carboxylic acid particles and photosensitive silver halide grains, a reducing agent for silver ions and a binder and other constituent layers, wherein 80-100 mol% of the non-photosensitive silver salt of aliphatic carboxylic acid particles are composed of silver behenate, and the silver salt photothermographic dry imaging material contains a fluorochemical surfactant represented by formula (1): Rf-(O-Rf')<SB>n</SB>-L-X<SB>m</SB>in at least one of the constituent layers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a silver salt photothermographic dry imaging material excellent in raw storage stability and stability of a silver image after heat development while maintaining low fog and high density, and without occurrence of coating unevenness, and image using the same The present invention relates to a recording method and an image forming method.

  Conventionally, in the medical and printing plate making fields, waste liquids resulting from wet processing of image forming materials have been a problem in terms of workability. In recent years, reduction of waste processing liquids has been strongly desired from the viewpoint of environmental conservation and space saving. It is rare. Therefore, silver salt photothermographic dry imaging materials capable of forming an image only by applying heat have been put into practical use and are rapidly spreading in the above fields.

  Silver salt photothermographic dry imaging materials (hereinafter also referred to as photothermographic materials, photothermographic materials or simply photosensitive materials) have been proposed for a long time (see, for example, Patent Documents 1 and 2).

  This heat-developable material is usually processed by a heat-development processing apparatus called a heat-development processor that applies stable heat to the heat-developable material to form an image. As described above, with the rapid spread of thermal development materials in recent years, a large amount of this thermal development processing apparatus has been supplied to the market.

  However, depending on the temperature and humidity environment during heat development processing, the slipperiness changes between the heat development material and the transport roller or processing member of the heat development processing apparatus, resulting in poor transport and density unevenness. was there. Another problem is that the silver image density of the heat-developable material formed fluctuates due to long-term storage. It has been found that these phenomena remarkably occur in a heat-developable material that forms an image by heat development after image exposure by laser light.

  In recent years, there has been a demand for a compact laser imager and a quick process. In order to obtain a sufficient density of the heat-developable material even if rapid processing is carried out, a silver halide having a small average grain size is used and the covering power is increased by increasing the number of development points, A method using a highly active reducing agent having a secondary alkyl group or a development accelerator such as a phenol compound, a hydrazine compound or a vinyl compound has been proposed (see, for example, Patent Documents 3 and 4).

  However, in order to increase the covering power, if silver halide grains with a small average grain size are used, the dispersion stability of the silver halide grains is impaired, rather the covering power is reduced and the image transparency is reduced. As a result, there is a problem that the haze at the low concentration portion deteriorates. Furthermore, when these techniques are used, the density change (printout) increases during long-term storage after heat development processing, and the silver tone of the obtained image becomes the same as that of an image obtained from a conventional wet development type photosensitive material. There was a problem that it was very different from the silver tone (for example, yellowish). Further, when silver halide grains having a small average grain size are used, there is a new problem that the color tone is reddish in a high density portion having a density of 2.0 or more.

To solve the above problems, a technique for adjusting the silver tone using a coupler or a leuco dye has been disclosed (see, for example, Patent Documents 5, 6, and 7). When the amount of the leuco dye used is increased, fogging increases during long-term storage, and thus there is a problem that the desired silver tone cannot be adjusted.
US Pat. No. 3,152,904 US Pat. No. 3,457,075 JP-A-11-295844 JP-A-11-352627 Japanese Patent Laid-Open No. 11-288057 Japanese Patent Laid-Open No. 11-231460 JP 2001-264926 A

  The present invention has been made in view of the above problems, and an object of the present invention is a silver salt photothermographic dry imaging material having low fog, high density, excellent storage stability, and low density unevenness, and an image using the same It is to provide a recording method and an image forming method.

  The above object of the present invention can be achieved by the following constitution.

(Claim 1)
On the support, non-photosensitive aliphatic carboxylic acid silver salt particles, a photosensitive silver halide emulsion containing photosensitive silver halide grains, a photosensitive layer and a constituent layer containing a silver ion reducing agent and a binder are provided. In the silver salt photothermographic dry imaging material, 80 mol% or more and 100 mol% or less of the non-photosensitive aliphatic carboxylate silver salt particles are composed of silver behenate, and at least one of the constituent layers has the following general formula ( 1. A silver salt photothermographic dry imaging material comprising the fluorine-based surfactant represented by 1).

General formula (1)
_{Rf- (O-Rf ') n} -L-X m
[Wherein, Rf represents an alkyl group, aryl group or alkenyl group containing at least one fluorine atom, Rf ′ represents an alkylene group containing at least one fluorine atom, and L represents a simple bond or linking group. X represents a hydroxy group, an anionic group or a cationic group. n represents the integer of 1-10, respectively, and m represents the integer of 1-3. ]
(Claim 2)
On the support, non-photosensitive aliphatic carboxylic acid silver salt particles, a photosensitive silver halide emulsion containing photosensitive silver halide grains, a photosensitive layer and a constituent layer containing a silver ion reducing agent and a binder are provided. In the silver salt photothermographic dry imaging material, 80 mol% or more of the non-photosensitive aliphatic carboxylate silver salt particles are composed of silver behenate, and at least one of the constituent layers is represented by the following general formula (2). A silver salt photothermographic dry imaging material characterized by containing a fluorinated surfactant.

General formula (2)
_{[(Rf 3 O) n2 - (} PFC) -CO-Y 2 ] _{k -L 2 - (X 2)} m2
[In the formula, Rf ₃ represents a perfluoroalkyl group having 1 to 4 carbon atoms, (PFC) represents a perfluorocycloalkylene group, Y ₂ represents a linking group containing an oxygen atom or a nitrogen atom, L ₂ represents a simple bond or linking group, X ₂ represents a water-solubilizing polar group containing an anionic group, a cationic group, a nonionic group or an amphoteric group, n2 represents an integer of 1 to 5, Represents an integer of 1 to 3, and m2 represents an integer of 1 to 5. ]
(Claim 3)
The silver salt photothermographic dry imaging material according to claim 1 or 2, wherein the total silver amount per 1 m ^{2 of the} photosensitive layer is 1.0 to 1.6 g.

(Claim 4)
The silver salt photothermographic dry imaging material according to any one of claims 1 to 3, wherein an alkaline solution of potassium hydroxide is used when forming the non-photosensitive aliphatic carboxylate silver salt particles.

(Claim 5)
An image recording method for a silver salt photothermographic dry imaging material, wherein the exposure to the silver salt photothermographic dry imaging material according to any one of claims 1 to 4 is a laser beam having a longitudinal multi.

(Claim 6)
A silver salt photothermographic material, wherein the silver salt photothermographic dry imaging material image-recorded by the silver salt photothermographic dry imaging material image recording method according to claim 5 is heated and developed at a temperature of 80 ° C to 200 ° C. Image forming method of photographic dry imaging material.

  According to the present invention, it is possible to provide a silver salt photothermographic dry imaging material having low fog and high density, excellent storage stability and less density unevenness, and an image recording method and an image forming method using the same.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

  The present invention will be described in more detail.

  In the silver salt photothermographic dry imaging material of the present invention, the constitution defined in any one of claims 1 and 2 is less likely to cause deterioration in coating properties and uneven density even when the coating speed is increased. In addition, a photothermographic material maintaining and improving the apparatus transportability can be obtained. Furthermore, by adopting the configuration defined in claim 3, the covering power can be effectively increased, and a heat developing material capable of achieving a high image density can be obtained.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  The silver salt photothermographic dry imaging material of the present invention contains, on a support, non-photosensitive aliphatic carboxylic acid silver salt particles, a photosensitive emulsion containing photosensitive silver halide particles, a silver ion reducing agent, and a binder. It has a photosensitive layer.

  The fluorine-based surfactant represented by the general formula (1) and the fluorine-based surfactant represented by the general formula (2) according to the present invention will be described.

  In the general formula (1), Rf represents an alkyl group, aryl group or alkenyl group containing at least one fluorine atom, preferably having 1 to 18 carbon atoms, more preferably 2 to 12 carbon atoms. It is preferable that it is 3-7 especially.

  Rf ′ represents an alkylene group containing at least one fluorine atom, and preferably has 1 to 8 carbon atoms, more preferably 2 to 5 carbon atoms, and particularly preferably 2 or 3 carbon atoms. .

Further, 'as the _n, for example _{(O-Rf 1 (O-} Rf)') k - group of _{(O-Rf 2 ') l} ( However, k + l = n) as shown in a different (O-Rf') It may be a body. n and m are each an integer of 1 or more, n is 1 or more and 10 or less, and m is 1 or more and 3 or less.

  L represents a simple bond or a linking group, but an alkylene group, an arylene group, or a divalent linking group containing a hetero atom is preferable.

  X represents a hydroxy group, an anionic group or a cationic group. As the anionic group, for example, a carboxyl group, a sulfonic acid group, and a phosphoric acid group are preferable. As a counter cation, for example, an alkali such as sodium ion or potassium ion is used. Metal ions, ammonium ions and the like are preferable. As the cationic group, a quaternary alkylammonium group is preferable, and as the counter anion, for example, a halide ion, p-toluenesulfonate ion and the like are preferable.

[Exemplary Compound Represented by General Formula (1)]
_{1-1: C 5 F 11 - (} O-CF 2) -O-PO (ONa) 2
_{1-2: HC 6 F 12 - (} O-CF 2) -O-PO (ONa) 2
_{1-3: C 8 F 17 - (} O-CF 2) -O-PO (ONa) 2
_{1-4: C 10 F 21 - (} O-CF 2) -O-PO (ONa) 2
_{1-5: C 12 F 25 - (} O-CF 2) -O-PO (ONa) 2
_{1-6: C 3 F 7 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-7: C 4 F 9 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-8: C 5 F 11 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-9: C 6 F 12 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-10: C 7 F 15 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-11: C 9 F 19 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-12: C 11 F 23 - (} O-C 2 F 4) -O-PO (ONa) 2
_{1-13: C 3 F 7 - (} O-CF 2) 6 -O-PO (ONa) 2
_{1-14: C 4 F 9 - (} O-CF 2) 6 -O-PO (ONa) 2
_{1-15: C 5 F 11 - (} O-CF 2) 5 -O-PO (ONa) 2
_{1-16: HC 6 F 12 - (} O-CF 2) 3 -O-PO (ONa) 2
1-17: C ₃ F ₇ - [O- (CF _{2) 3]} -COONa
1-18: C ₄ F ₉ - [O- (CF _{2) 3]} -COONa
1-19: C ₅ F ₁₁ - [O- (CF _{2) 3]} -COONa
1-20: HC ₇ F ₁₄ - [O- (CF _{2) 3]} -O-CH (COONa) ₂
1-21: C ₈ F ₁₇ - [O- (CF _{2) 3]} -O-CH (COONa) ₂
1-22: C ₃ F ₇ - [O- (CF _{2) 5]} -COONa
1-23: C ₄ F ₉ - [O- (CF _{2) 5]} -COONa
1-24: C ₅ F ₁₁ - [O- (CF _{2) 5]} -COONa
1-25: C ₇ F ₁₅ - [O- (CF _{2) 5]} -COONa
_{1-26: C 3 F 7 - (} O-C 2 F 4) 5 -COONa
_{1-27: C 4 F 9 - (} O-C 2 F 4) 2 -COONa
_{1-28: C 5 F 11 - (} O-C 2 F 4) 2 -COONa
_{1-29: HC 7 F 14 - (} O-C 2 F 4) 2 -COONa
_{1-30: C 9 F 19 - (} O-C 2 F 4) 2 -COONa
_{1-31: C 2 F 5 - (} O-C 2 F 4) 3 -COONa
_{1-32: C 2 F 5 - (} O-C 2 F 4) 5 -COONa
_{1-33: C 3 F 7 - (} O-C 2 F 4) 4 -COONa
_{1-34: C 4 F 9 - (} O-C 2 F 4) 3 -COONa
_{1-35: C 5 F 11 - (} O-C 2 F 4) 3 -NHCOCH (COONa) 2
_{1-36: HC 6 F 12 - (} O-C 2 F 4) 3 -NHCOCH (COONa) 2
_{1-37: C 4 F 9 - (} O-C 2 F 4) 2 -OCF 2 COONa
_{1-38: C 5 F 11 - (} O-C 2 F 4) 2 -OCF 2 COONa
_{1-39: C 7 F 15 - (} O-C 2 F 4) 2 -OCF 2 COONa
_{1-40: C 4 F 9 -OCF 2} - [O- (CF _{2) 5]} -COOK
_{1-41: C 5 F 11 -OCF 2} - [O- (CF _{2) 5]} -COOK
_{1-42: HC 6 F 12 -OCF 2} - [O- (CF _{2) 5]} -COOK
_{1-43: C 4 F 9 - (} O-C 2 F 4) 5 - [O- (CF _{2) 3]} -COOK
_{1-44: C 5 F 11 - (} O-C 2 F 4) 2 - [O- (CF _{2) 3]} -COOK
_{1-45: C 6 F 13 - (} O-C 2 F 4) 2 - [O- (CF _{2) 3]} -COOK
_{1-46: C 12 F 25 - (} O-CF 2) -O-SO 3 Na
_{1-47: C 7 F 15 - (} O-C 2 F 4) -OC 3 H 6 -SO 3 Na
_{1-48: C 4 F 9 - (} O-CF 2) 6 -O-SO 3 Na
_{1-49: HC 5 F 10 - (} O-CF 2) 5 -OC 3 H 6 -SO 3 Na
_{1-50: HC 6 F 12 - (} O-CF 2) 3 -O-SO 3 Na
_{1-51: C 5 F 11 - (} O-C 2 F 4) 2 -OC 3 H 6 -SO 3 Na
_{1-52: C 7 F 15 - (} O-C 2 F 4) 2 -O-SO 3 Na
_{1-53: C 3 F 7 - (} O-C 2 F 4) 4 -OC 3 H 6 -SO 3 Na
1-54: C ₄ F ₉ — (O—C ₂ F ₄ ) ₃ —O—SO ₃ Na
1-55: HC ₅ F _10- (O—C ₂ F ₄ ) ₃ —OC ₃ H ₆ —SO ₃ Na
1-56: C ₅ F ₁₁ —OCF ₂ — [O— (CF ₂ ) ₅ ] —O—SO ₃ Na
_{1-57: C 4 F 9 - (} O-C 2 F 4) 2 - [O- (CF _{2) 3]} -O-SO ₃ Na
_{1-58: (HCF 2) 3 C-} (O-C 2 F 4) 3 -O-SO 3 Na
_{1-59: (CF 3) 2 CFCF} 2 CF 2 - (O-CF 2) 5 -OC 3 H 6 -SO 3 Na
_{1-60: C 11 F 23 - (} O-C 2 F 4) -O-SO 3 Na
1-61: C ₄ F ₉ — (O—C ₂ F ₄ ) ₃ —NHCO— (CH ₂ ) ₃ —N ⁺ (CH ₃ ) ₃ .Br ⁻
_{1-62: C 5 F 11 - (} O-C 2 F 4) 2 -NHCO- (CH 2) 3 -N + (CH 3) 3 · Br -
1-63: HC ₆ F ₁₂ — (O—C ₂ F ₄ ) ₂ —NHCO— (CH ₂ ) ₃ —N ⁺ (CH ₃ ) ₃ .Br—
1-64: C ₄ F ₉ — (O—C ₂ F ₄ ) ₃ —O—CH ₂ —N ⁺ (CH ₃ ) ₂ (C ₂ H ₄ OH) · Br ⁻
_{1-65: C 5 F 11 - (} O-C 2 F 4) 2 -O-CH 2 -N + (CH 3) 2 (C 2 H 4 OH) · Br -
1-66: HC ₆ F ₁₂ — (O—C ₂ F ₄ ) ₂ —O—CH ₂ —N ⁺ (CH ₃ ) ₂ (C ₂ H ₄ OH) · Br ⁻
_{1-67: C 5 F 11 -OCF 2} - (O-C 2 F 4) -NHCO- (CH 2) 3 -N + (CH 3) 3 · Br -
1-68: (CF ₃ ) ₃ C— (O—C ₂ F ₄ ) ₃ —O—CH ₂ —N ⁺ (CH ₃ ) ₂ (C ₂ H ₄ OH) · Br ⁻
_{1-69: C 12 F 25 - (} O-CF 2) -OH
_{1-70: C 7 F 15 - (} O-C 2 F 4) -OH
1-71: C ₄ F ₉ — (O—CF ₂ ) ₆ —OC ₃ H ₆ —OH
_{1-72: C 5 F 11 - (} O-CF 2) 5 -OC 3 H 6 -OH
1-73: HC ₆ F ₁₂ — (O—CF ₂ ) ₃ —OH
_{1-74: C 5 F 11 - (} O-C 2 F 4) 2 -OC 3 H 6 -OH
_{1-75: C 7 F 15 - (} O-C 2 F 4) 2 -OC 3 H 6 -OH
1-76: C ₃ F ₇ — (O—C ₂ F ₄ ) ₄ —OC ₃ H ₆ —OH
1-77: HC ₄ F ₈ — (O—C ₂ F ₄ ) ₃ —O—C (C ₂ H ₄ OH) _{3
1-78: C 5 F 11 - (} O-C 2 F 4) 3 -OC 3 H 6 -OH
_{1-79: C 5 F 11 -OCF 2} - [O- (CF _{2) 5]} -OH
_{1-80: C 4 F 9 - (} O-C 2 F 4) 2 - [O- (CF _{2) 3!} -OH
1-81: (CF ₃ ) ₃ C— (O—C ₂ F ₄ ) ₃ —OH
_{1-82: (HCF 2) 2 CFCF} 2 CF 2 - (O-CF 2) 5 -OH
1-83: C ₁₁ F ₂₃ — (O—C ₂ F ₄ ) ₄ OH
With respect to the method for synthesizing each fluorine-based surfactant represented by the general formula (1), JP-T-10-500950 and JP-A-11-504360 can be referred to.

[Exemplary Compound Represented by General Formula (2)]
2-1: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ COO ⁻
2-2: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ SO ₃ ⁻
2-3: (CF ₃ O) (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ SO ₃ ⁻
2-4: (CF ₃ O) ₃ (PFC ′)-CON (C ₃ H ₆ SO ₃ ⁻ ) C ₃ H ₆ N ⁺ (CH ₃ ) ₂ H
_{2-5: (CF 3 O) (} PFC ') - CON (C 3 H 6 SO 3 -) C 3 H 6 N + (CH 3) 2 H
2-6: [(CF ₃ O) ₃ (PFC ′) — COOCH ₂ ] ₂ CH—CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ SO ₃ ⁻
2-7: [(CF ₃ O) ₂ (PFC ′)-COOCH ₂ ] ₂ CH—CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ SO ₃ ⁻
2-8: [(CF ₃ O) (PFC ′) — COOCH ₂ ] ₂ CH—CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ SO ₃ ⁻
2-9: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ OH · Cl ⁻
2-10: (CF ₃ O) ₂ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ OH · Cl ⁻
2-11: (CF ₃ O) (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ C ₂ H ₄ OH · Cl ⁻
2-12: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-13: (CF ₃ O) ₂ (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-14: (CF ₃ O) (PFC ′)-CONHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-15: [(CF ₃ O) ₃ (PFC ′) — COOCH ₂ ] ₂ C (CH ₃ ) N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-16: [(CF ₃ O) ₂ (PFC ′) — COOCH ₂ ] ₂ C (CH ₃ ) N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-17: [(CF ₃ O) (PFC ′) — COOCH ₂ ] ₂ C (CH ₃ ) N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-18: [(CF ₃ O) ₃ (PFC ′) — COOCH ₂ ] ₂ CHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-19: [(CF ₃ O) ₂ (PFC ′) — COOCH ₂ ] ₂ CHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-20: [(CF ₃ O) (PFC ′) — COOCH ₂ ] ₂ CHC ₃ H ₆ N ⁺ (CH ₃ ) ₂ H · Cl ⁻
2-21: (CF ₃ O) ₃ (PFC ′) — COO (C ₂ H ₄ O) ₁₂ H
2-22: (CF ₃ O) ₂ (PFC ′) — COO (C ₂ H ₄ O) ₁₂ H
2-23: (CF ₃ O) (PFC ′) — COO (C ₂ H ₄ O) ₁₂ H
2-24: (CF ₃ O) ₃ (PFC ′) — COO (C ₂ H ₄ O) ₁₅ CH _{3
2-25: (CF 3 O) 2} (PFC ') - COO (C 2 H 4 O) 15 CH 3
2-26: (CF ₃ O) (PFC ′) — COO (C ₂ H ₄ O) ₁₅ CH ₃
2-27: [(CF ₃ O) ₃ (PFC ′)-COOCH ₂ ] ₂ CHC ₃ H ₆ OH
2-28: [(CF ₃ O) ₂ (PFC ′)-COOCH ₂ ] ₂ CHC ₃ H ₆ OH
2-29: [(CF ₃ O) (PFC ′)-COOCH ₂ ] ₂ CHC ₃ H ₆ OH
2-30: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ COONa
2-31: (CF ₃ O) ₂ (PFC ′)-CONHC ₃ H ₆ COONa
2-32: (CF ₃ O) (PFC ′)-CONHC ₃ H ₆ COOK
2-33: (CF ₃ O) ₃ (PFC ′)-CONHC ₃ H ₆ SO ₃ Na
2-34: (CF ₃ O) ₂ (PFC ′)-CONHC ₃ H ₆ SO ₃ Na
2-35: (CF ₃ O) (PFC ′)-CONHC ₃ H ₆ SO ₃ K
2-36: (CF ₃ O) ₃ (PFC ′)-CON (C ₃ H ₆ SO ₃ Na) C ₃ H _{7
2-37: (CF 3 O) 2} (PFC ') - CON (C 3 H 6 SO 3 Na) C 3 H 7
2-38: (CF ₃ O) (PFC ′) — CON (C ₃ H ₆ SO ₃ Na) C ₃ H ₇
2-39: [(CF ₃ O) ₃ (PFC ′)-COOCH ₂ ] ₂ C (CH ₃ ) COONa
2-40: [(CF ₃ O) ₂ (PFC ′)-COOCH ₂ ] ₂ C (CH ₃ ) COONa
2-41: [(CF ₃ O) (PFC ′) — COOCH ₂ ] ₂ C (CH ₃ ) COONa
2-42: [(CF ₃ O) ₃ (PFC ′)-COOCH ₂ ] ₂ C (COONa) ₂
2-43: [(CF ₃ O) ₂ (PFC ′)-COOCH ₂ ] ₂ C (COONa) ₂
2-44: [(CF ₃ O) (PFC ′)-COOCH ₂ ] ₂ C (COONa) ₂
2-45: [(CF ₃ O) ₃ (PFC ′)-COOCH ₂ ] ₂ C (CH ₃ ) SO ₃ Na
2-46: [(CF ₃ O) ₂ (PFC ′)-COOCH ₂ ] ₂ C (CH ₃ ) SO ₃ Na
2-47: [(CF ₃ O) (PFC ′) — COOCH ₂ ] ₂ C (CH ₃ ) SO ₃ Na
2-48: _{[(CF 3 O) 3 (PFC} ') - COOCH 2 ] ₂ CHC ₃ H ₆ SO ₃ Na
2-49: _{[(CF 3 O) 2 (PFC} ') - COOCH 2 ] ₂ CHC ₃ H ₆ SO ₃ Na
2-50: _{[(CF 3 O) (PFC '} ) - COOCH 2 ] ₂ CHC ₃ H ₆ SO ₃ Na
In each surfactant represented by the above general formula (2), (PFC ′) represents a perfluorocyclohexylene group, and the substitution position of (CF ₃ O) is ( In the case of CF ₃ O) ₃ , they are in the 3rd, 4th and 5th positions, in the case of (CF ₃ O) ₂ they are in the 3rd and 4th positions, and in the case of (CF ₃ O) they are in the 4th position.

  JP, 10-158218, A special table 2000-505803 can be referred to for the synthesis method of each fluorochemical surfactant denoted by the above-mentioned general formula (2).

Amount of fluorinated surfactant according to the present invention is preferably from 0.01 to 200 mg / m ^2, more preferably 0.1-100 mg / m ^2, and most preferably more 0.5~80mg / m ² .

  The layer containing the fluorosurfactant according to the present invention is preferably the layer farthest from the support, whether on the photosensitive layer side or on the opposite back layer.

  In the present invention, in addition to the above-described fluorosurfactant according to the present invention, a fluorine-containing compound having a fluoroalkyl group having 18 to 40 fluorine atoms or a fluoroalkenyl group having 17 to 40 fluorine atoms. It is also preferable to use a fluorine-containing compound having

  The following general formula (3) is mentioned as a preferred structural formula of the fluorine-containing compound.

In the formula, Rf ₁ and Rf ₂ are alkyl groups that are fluorine-substituted so that the total fluorine atoms of Rf ₁ and Rf ₂ are 18 to 40, or alkenyl that is fluorine-substituted so that the total fluorine atoms is 17 to 40 Represents a group. m3, n3, and n4 represent 0 or 1. A and B represent a divalent linking group and may be the same or different. M represents a cation.

  Specific examples of preferable fluorine-containing compounds including the compound represented by the general formula (3) are shown below.

_{F-6 C 9 F 17 -O-} (CH 2 CH 2 O) 35 -C 9 F 17
_{F-7 C 9 F 17 -O-} (CH 2 CH 2 O) 22 -SO 3 Na
F-8 C ₉ F ₁₇ —O—C ₆ H ₄ —SO ₃ Na
_{F-9 C 9 F 17 -O-} (CH 2 CH 2 O) 20 -CH 3
_{F-10 C 9 F 17 -O-} (CH 2 CH 2 O) 20 -H
F-11 C ₉ F ₁₉ —O—C ₆ H ₄ —SO ₃ Na
In the present invention, the fluorine-containing compound is preferably a fluorine-containing surfactant. The amount of the compound represented by the general formula (3) is preferably 0.1 to 200 mg / m ² , more preferably 0.2 to 100 mg / m ² , and further 0.5 to 80 mg / m ^2. Most preferred. The layer containing the fluorine-containing compound is preferably the layer farthest from the support, whether on the photosensitive layer side or on the opposite back layer.

In the present invention, an anionic surfactant and a nonionic surfactant that do not contain a fluorine atom are preferably used in combination with the compound represented by the general formula (3). In that case, the addition amount of these anionic surfactants and nonionic surfactants is preferably 0.1 to 300 mg / m ² , more preferably 1 to 200 mg / m ² .

  As a preferred structure of the anionic surfactant, the following general formula (4) can be mentioned.

In the formula, R ₁ and R ₂ represent a substituted or unsubstituted alkyl group or an alkenyl group, and both may be the same or different. The sum of the number of carbon atoms of R ₁ + R ₂ is 8-14. l4 represents 0 or 1; M ₄ represents a cation.

In the general formula (4), linear alkyl having 10 to 13 carbon atoms in which R4 = 0, R ₁ and R ₂ are preferable.

  Examples of preferred specific compounds represented by formula (4) are shown below.

  Moreover, the following general formula (5) is mentioned as a preferable structure of another anionic surfactant.

In the formula, R ₂₁ represents an alkyl group having 1 to 18 carbon atoms, R ₂₂ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, M ₂₁ represents a cation, and n5 represents 1 to 10. x represents 0 or 1, B ₂ represents a linking group having 1 or 2 carbon atoms, and y represents 0 to 2.

Preferably, the total number of carbon atoms of R ₂₁ and R ₂₂ is 15 or less, and n5 is preferably 3-5.

  Further, those having an HLB (water immersion new oil balance) of 12 or more are preferable. The solubility in water at 25 ° C. is preferably 50 g / liter or more.

A preferable addition amount of the anionic surfactant represented by the general formula (5) is 1 to 1000 mg, more preferably 10 to 100 mg, per 1 m ² of the photosensitive material.

  The solvent for addition includes organic solvents such as methyl ethyl ketone and alcohol, but they may be directly added and dissolved in the coating solution without a solvent. The layer to be added is not particularly limited, but a layer outside the photosensitive layer as viewed from the support is preferable, and an outermost layer is more preferable. Further, when added to the back layer, the outer layer is preferable from the viewpoint of the support, and the outermost layer is more preferable.

In photosensitive materials for medical diagnosis, antistatic technology is known by reducing the surface resistance by using a surfactant having a polyoxyalkylene group. In this case, in order to maintain sufficient antistatic performance Is preferably 10 ¹⁴ Ω or less, more preferably 10 ¹³ Ω or less, in an atmosphere having a surface resistivity of 23 ° C. and 20% RH.

  Although the specific example of an anionic surfactant represented by General formula (5) is shown, this invention is not limited to these.

  As a preferred structure of the nonionic surfactant, the following general formula (6) can be mentioned.

In the formula, R ₁₁ represents a substituted, unsubstituted alkyl group or alkenyl group having 1 to 30 carbon atoms, and m11 and n11 may be the same or different and each is 1 to 50. m21 and n21 are each 0 to 50. Preferably m1 + n1 is 5-40. The carbon number of R ₁₁ is preferably 8-18. m21 and n21 are preferably such that m21 + n12 is 0 to 40. More preferably, both m21 + n12 are 0.

  Specific examples of the nonionic surfactant represented by the general formula (6) are shown below, but the present invention is not limited thereto.

  Another preferable structure of the nonionic surfactant is listed below.

N-1 C ₁₆ H ₃₃ O (CH ₂ CH ₂ O) ₁₀ H
N-2 C ₁₁ H ₂₃ CONH (CH ₂ CH ₂ O) _n H n = 5, 10, 15
_{N-3 C 9 H 19 -} (C 6 H 4) -O (CH 2 CH 2) n H
n = 10, 20, 30, 40

These nonionic surfactants can be easily obtained as commercial products. The layer to which the nonionic surfactant is added is not particularly limited, but a layer far from the support is preferable, and most preferably added to the outermost layer. The addition amount, but preferably the photosensitive material 1 m ² per 1~1000mg further preferably photosensitive material 1 m ² per 10-100 mg.

  Next, a photosensitive emulsion containing photosensitive silver halide grains will be described.

  In the silver salt photothermographic dry imaging material of the present invention, a photosensitive silver halide emulsion (hereinafter also simply referred to as a photosensitive emulsion) is a photosensitive silver halide grain having a particle size of 0.001 μm or more and 0.050 μm or less. The ratio is preferably 50% by mass or more of the total photosensitive silver halide grains in terms of silver amount. More preferably, it is 75-100 mass%, More preferably, it is 90-100 mass%.

  In the present invention, the size of the photosensitive silver halide grains is preferably 0.001 to 0.050 [mu] m, more preferably 0.01 to 0.05 [mu] m in terms of average particle diameter. The average particle diameter here means the volume of the silver halide grains in the case where the silver halide grains are so-called normal crystals such as cubes and octahedrons, other than normal crystals, for example, spherical particles, rod-like grains, etc. The diameter when considering a sphere equivalent to the so-called sphere equivalent diameter. In the case where the silver halide grains are tabular grains, the diameter is the diameter when converted into a circular image having the same area as the projected area of the main surface.

The addition amount of the photosensitive silver halide, the coating amount of silver per heat development material 1 m ^2, is preferably 0.01~0.8g / m ^2, is 0.01~0.4g / m ² More preferably, it is most preferable that it is 0.01-0.2 g / m < ² >.

By making the photosensitive silver halide grain size and addition amount the above-mentioned preferable conditions, the photographic performance is improved, the density at the same silver amount is improved, the haze (turbidity) is reduced, and the image quality is improved. Can be improved. When the grain size is less than 0.001 μm, the sensitivity is remarkably lowered, and the silver halide grains themselves can be prepared by a silver halide grain preparation process or an organic silver salt by simply reducing the grain size of the silver halide grains. Aggregation occurs in this preparation step, the particle size distribution is remarkably widened, and haze (turbidity) cannot be sufficiently reduced. On the other hand, if it exceeds 0.05 μm, haze (turbidity) becomes a problem. Further, it is less than the amount of coated silver is 0.01 g / m ^2, intended function as a heat developable material is insufficient, a sufficient photographic performance obtained, the haze exceeds 0.8 g / m ² (turbidity) of It becomes a problem.

  The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be continuously changed. Further, silver halide grains having a core / shell structure can be preferably used. What is preferable as the structure is a structure having a halogen composition of 2 to 5 layers, and more preferably 2 to 4 layers of core / shell particles can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

  As a method for forming the photosensitive silver halide, a method known in the art, for example, a method described in Research Disclosure No. 17029 in June 1978 and US Pat. No. 3,700,458 can be used. More specifically, a method is used in which a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, and then mixed with an organic silver salt.

  Examples of the shape of the silver halide grains include cubes, octahedrons, tabular grains, spherical grains, rod-shaped grains, potato-shaped grains, etc. In the present invention, cubic grains and tabular grains are particularly preferable. . A preferable value as an average aspect ratio in the case of using tabular silver halide grains is 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can be preferably used. The surface index (Miller index) of the outer surface of the photosensitive silver halide grain is not particularly limited, but the spectral sensitizing efficiency when adsorbed by the spectral sensitizing dye is high and the proportion of the [100] plane is high. Is preferred. The ratio is preferably 50% or more, more preferably 65% or more, and still more preferably 80% or more. The ratio of the Miller index [100] plane is calculated by using the adsorption dependency between the [111] plane and the [100] plane in the adsorption of the sensitizing dye. Tani; Imaging Sci. 29, 165 (1985).

  In the present invention, the silver halide grains according to the present invention can contain an iridium compound. As the water-soluble iridium compound used in the present invention, various compounds can be used. For example, iridium (III) halide compounds, iridium (III) halide compounds, iridium complex salts as ligands, halogens, amines Having oxalato, for example, hexachloroiridium (III) or (IV) complex salt, hexaammineiridium (III) or (IV) complex salt, trioxalatoiridium (III) or (IV) complex salt, hexacyanoiridium, pentachloro And nitrosyliridium. In the present invention, among these compounds, III-valent and IV-valent compounds can be used in any combination. These iridium compounds are used after being dissolved in water or an appropriate solvent, and are generally used in order to stabilize a solution of the iridium compound, that is, an aqueous hydrogen halide solution (for example, hydrochloric acid, odorous acid, fluorine, etc.). Acid) or an alkali halide (for example, KCl, NaCl, KBr, NaBr, etc.) can be used. Instead of using water-soluble iridium, it is also possible to add another silver halide grain previously doped with iridium and dissolve it at the time of silver halide preparation.

  In the present invention, the addition of the water-soluble iridium compound can be appropriately carried out at the time of producing the silver halide emulsion grains and at any time before coating the coating solution containing the silver halide emulsion. It is preferably added during emulsion formation and incorporated in the silver halide grains.

The amount of these water-soluble iridium compounds added is preferably in the range of 1 × 10 ⁻⁸ to 1 × 10 ⁻³ mol per mol of silver halide, more preferably in the range of 1 × 10 ^{−8 to} 5 × 10 ⁻⁵ mol. A range of 5 × 10 ^{−8 to} 5 × 10 ⁻⁶ mol is particularly preferable.

The photosensitive silver halide grain according to the present invention can contain, in addition to iridium, a metal or metal complex of Group VII or Group VIII (Group 7 to 10) of the other periodic table. Such a central metal is preferably rhodium, rhenium, ruthenium, or osmium. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The content is preferably in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻³ mol, more preferably in the range of 1 × 10 ⁻⁸ to 1 × 10 ⁻⁴ mol, with ^respect to 1 mol of silver. As a specific metal complex structure, a metal complex having a structure described in JP-A-7-225449 can be used.

  As the rhodium compound used in the present invention, a water-soluble rhodium compound can be used. For example, a rhodium (III) halide compound or a rhodium complex salt having a halogen, amines, oxalato, etc. as a ligand, such as hexachlororhodium (III) complex salt, pentachloroacorodium (III) complex salt, tetrachlorodia Examples thereof include a corodium (III) complex salt, a hexabromorhodium (III) complex salt, a hexaammine rhodium (III) complex salt, and a trizaratrodium (III) complex salt. These rhodium compounds are used by dissolving in water or a suitable solvent. In order to stabilize the rhodium compound solution, a generally used method is used, that is, an aqueous hydrogen halide solution (for example, hydrochloric acid, odorous acid, hydrofluoric acid). Etc.) or a method of adding an alkali halide (for example, KCl, NaCl, KBr, NaBr, etc.) can be used. Instead of using water-soluble rhodium, it is also possible to add another silver halide grain previously doped with rhodium at the time of silver halide preparation and dissolve it.

The addition amount of these rhodium compounds is preferably in the range of 1 × 10 ^{−8 to} 5 × 10 ⁻⁶ mol, particularly preferably 5 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol, per mol of silver halide.

  These compounds can be added as appropriate during the production of silver halide emulsion grains and at any stage prior to the application of a coating solution containing a silver halide emulsion. The silver halide grains are preferably incorporated into the silver halide grains.

  Rhenium, ruthenium and osmium used in the present invention are added in the form of water-soluble complex salts described in JP-A-63-2042, JP-A-1-285941, JP-A-2-20852, JP-A-2-20855, etc. Is done. Particularly preferred is a hexacoordination complex represented by the following formula.

[ML ₆ ] ^n-
Here, M represents Ru, Re, or Os, L represents a ligand, and n represents 0, 1, 2, 3, or 4.

  In this case, the counter ion has no significance and ammonium or alkali metal ions are used. Preferred ligands include halide ligands, cyanide ligands, cyanide oxide ligands, nitrosyl ligands, thionitrosyl ligands, and the like.

  Examples of specific complexes used in the present invention are shown below, but the present invention is not limited thereto.

[ReCl ₆ ] ³⁻ , [ReBr ₆ ] ³⁻ , [ReCl ₅ (NO)] ²⁻ , [Re (NS) Br ₅ ] ²⁻ , [Re (NO) (CN) ₅ ] ²⁻ , [Re (O) ₂ (CN) ₄ ] ³⁻ , [RuCl ₆ ] ³⁻ , [RuCl ₄ (H ₂ O) ₂ ] ⁻ , [RuCl ₅ (H ₂ O)] ²⁻ , [RuCl ₅ (NO)] ^2- , [RuBr ₅ (NS)] ²⁻ , [Ru (CO) ₃ Cl ₃ ] ²⁻ , [Ru (CO) Cl ₅ ] ²⁻ , [Ru (CO) Br ₅ ] ²⁻ , [OsCl ₆ ] ^3- , [OsCl ₅ (NO)] ²⁻ , [Os (NO) (CN) ₅ ] ²⁻ , [Os (NS) Br ₅ ] ²⁻ , [Os (O) ₂ (CN) ₄ ] ^{4 -}
The addition amount of these compounds is preferably in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻⁵ mol, particularly preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol, per mol of silver halide.

  These compounds can be added as appropriate during the preparation of the silver halide emulsion grains and at any time before the coating solution containing the silver halide emulsion is applied. The silver halide grains are preferably incorporated into the silver halide grains.

  In order to add these compounds during the formation of silver halide grains and incorporate them into the silver halide grains, an aqueous solution dissolved together with the powder of the metal complex or NaCl or KCl is dissolved in the water solubility during the formation of the silver halide grains. A method of adding silver salt or a water-soluble halide solution, a method of adding silver salt and a halide solution as a third solution when they are simultaneously mixed, and a method of preparing silver halide grains by a method of three-liquid simultaneous mixing, or There is a method of charging a required amount of an aqueous solution of a metal complex into a reaction vessel during the formation of silver halide grains. In particular, a method of adding a powder or an aqueous solution dissolved together with NaCl and KCl to the water-soluble halide solution is preferable.

  In this case, the counter ion has no significance and ammonium or alkali metal ions are used. Preferred ligands include halide ligands, cyanide ligands, cyanide oxide ligands, nitrosyl ligands, thionitrosyl ligands, and the like.

  Examples of specific complexes used in the present invention are shown below, but the present invention is not limited thereto.

[ReCl ₆ ] ³⁻ , [ReBr ₆ ] ³⁻ , [ReCl ₅ (NO)] ²⁻ , [Re (NS) Br ₅ ] ²⁻ , [Re (NO) (CN) ₅ ] ²⁻ , [Re (O) ₂ (CN) ₄ ] ³⁻ , [RuCl ₆ ] ³⁻ , [RuCl ₄ (H ₂ O) ₂ ] ⁻ , [RuCl ₅ (H ₂ O)] ²⁻ , [RuCl ₅ (NO)] ^2- , [RuBr ₅ (NS)] ²⁻ , [Ru (CO) ₃ Cl ₃ ] ²⁻ , [Ru (CO) Cl ₅ ] ²⁻ , [Ru (CO) Br ₅ ] ²⁻ , [OsCl ₆ ] ^3- , [OsCl ₅ (NO)] ²⁻ , [Os (NO) (CN) ₅ ] ²⁻ , [Os (NS) Br ₅ ] ²⁻ , [Os (O) ₂ (CN) ₄ ] ^{4 -}
The addition amount of these compounds is preferably in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻⁵ mol, particularly preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol, per mol of silver halide.

  These compounds can be added as appropriate during the preparation of the silver halide emulsion grains and at any time before the coating solution containing the silver halide emulsion is applied. The silver halide grains are preferably incorporated into the silver halide grains.

  In order to add these compounds during the formation of silver halide grains and incorporate them into the silver halide grains, an aqueous solution dissolved together with the powder of the metal complex or NaCl or KCl is dissolved in the water solubility during the formation of the silver halide grains. A method of adding silver salt or a water-soluble halide solution, a method of adding silver salt and a halide solution as a third solution when they are simultaneously mixed, and a method of preparing silver halide grains by a method of three-liquid simultaneous mixing, or There is a method of charging a required amount of an aqueous solution of a metal complex into a reaction vessel during the formation of silver halide grains. In particular, a method of adding a powder or an aqueous solution dissolved together with NaCl and KCl to the water-soluble halide solution is preferable.

  The silver halide emulsion according to the present invention is preferably subjected to chemical sensitization. As chemical sensitization, known methods such as sulfur sensitization, gold sensitization, selenium sensitization, tellurium sensitization, and noble metal sensitization can be used.

The sulfur sensitization preferably used in the present invention is usually carried out by adding a sulfur sensitizer and stirring the silver halide emulsion at a high temperature of 40 ° C. or higher for a predetermined 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, etc. Can be used. Preferred sulfur compounds are thiosulfate and thiourea compounds. The addition amount of the sulfur sensitizer is not uniform depending on various conditions such as pH at the time of chemical ripening, temperature, and the size of silver halide grains, but 1 × 10 ⁻⁷ to 1 × 10 10 per mol of silver halide. ^-2 mol, more preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol.

  A known selenium compound can be used as the selenium sensitizer used in the present invention. That is, it is usually carried out by adding an unstable or non-labile selenium compound and stirring the silver halide emulsion at a high temperature of 40 ° C. or higher for a predetermined time. As the unstable selenium compound, for example, compounds described in JP-B Nos. 44-15748, 43-13489, JP-A-4-25832, 4-109240, 4-324855 and the like can be used. . In particular, it is preferable to use compounds represented by the general formulas (VIII) and (IX) described in JP-A-4-324855.

  The tellurium sensitizer used in the present invention is a compound that generates silver telluride presumed to be a sensitization nucleus on the surface or inside of a silver halide grain. The silver telluride formation rate in the silver halide emulsion can be tested, for example, by the method described in JP-A-5-313284. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, and P = Te bonds. Compound, tellurocarboxylates, Te-organyl tellurocarboxylic acid esters, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having P-Te bonds, Te-containing heterocycles And tellurium carbonyl compounds, inorganic tellurium compounds, colloidal tellurium and the like can be used. Specifically, U.S. Patent Nos. 1,623,499, 3,320,069, 3,772,031, British Patent Nos. 235,211, 1,121,496, 1,295,462, 1,396,696, Canadian Patent 800,958, JP-A-4-204640, Patents 2654722, 2699029, 2811257, Journal of Chemical Society Chemical Communication (J. Chem. Soc. Chem. Commun.), 635 (1980), ibid, 1102 (1979), ibid, 645 (1979), Journal of Chemical Society Parkin Transaction 1 (J. Chem. Soc. Perkin. Trans. 1), 2191 (1 80), S. Edited by S. Patai, The Chemistry of Organic Selenium and Tellurium Compounds, Vol., The Chemistry of Organic Serenium and Tellunium Compounds. 1 (1986), Vol. 2 (1987) can be used. In particular, compounds represented by the general formulas (II), (III) and (IV) in JP-A-5-313284 are preferred.

Selenium used in the present invention, the amount of the tellurium sensitizer, silver halide grains to be used, but not uniform by chemical ripening condition and the like, in general, 1 mol of silver halide per 1 × 10- ⁸ to 1 × 10 ⁻² mol, preferably about 1 × 10 ⁻⁷ to 1 × 10 ⁻³ mol is used. The conditions for chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, preferably 7 to 10, and the temperature is 40 to 95 ° C, preferably 45. ~ 85 ° C.

  As the gold sensitizer used for gold sensitization to the silver halide emulsion according to the present invention, the gold oxidation number may be either +1 or +3, and a gold compound usually used as a gold sensitizer is used. be able to. Typical examples include chloroauric acid, potassium chloroaurate, auric trichloride, potassium auric thiocyanate, potassium iodoaurate, tetracyanoauric acid, ammonium aurothiocyanate, pyridyltrichlorogold and the like.

The amount of the gold sensitizer added varies depending on various conditions, but is generally 1 × 10 ⁻⁷ mol or more, 1 × 10 ⁻³ mol or less, more preferably 1 × 10 ⁻⁶ mol or more, per mol of silver halide. 5 × 10 ⁻⁴ mol or less.

  The silver halide emulsion according to the present invention can be used in combination with gold sensitization and other chemical sensitization. When used in combination with gold sensitization, for example, sulfur sensitization and gold sensitization are used. Method, selenium 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.

  In the silver halide emulsion used in the present invention, a cadmium salt, a sulfite salt, a lead salt, a thallium salt or the like may coexist in the process of silver halide grain formation or physical ripening.

  In the present invention, reduction sensitization can be used. As specific compounds for the reduction sensitization, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, etc. should be used. Can do. Further, reduction sensitization can be performed by ripening while maintaining the pH of the silver halide emulsion at 7 or more, or pAg at 8.3 or less. Further, reduction sensitization can be performed by introducing a single addition portion of silver ions during grain formation.

  A thiosulfonic acid compound may be added to the silver halide emulsion according to the present invention by the method shown in European Patent Publication No. 293,917.

  The photosensitive silver halide grain according to the present invention may be spectrally sensitized by adsorbing a spectral sensitizing dye. As spectral sensitizing dyes, cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine dyes, oxonol dyes, hemioxonol dyes, and the like can be used. For example, JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, JP-A-63-304242, JP-A-63-15245, U.S. Pat. The sensitizing dyes described in US Pat. Nos. 4,740,455, 4,741,966, 4,751,175, and 4,835,096 can be used. Useful sensitizing dyes used in the present invention are described in, for example, the literature described or cited in Section RD17643-A (December 1978, p.23), Section 18431X (August 1978, p.437). Yes. In particular, it is preferable to use a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various laser imagers and scanner light sources. For example, compounds described in JP-A Nos. 9-34078, 9-54409, and 9-80679 are preferably used.

  The silver halide emulsion contained in the heat-developable material according to the present invention may be one kind or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, those having different crystal habits, chemical Those having different sensitization conditions) may be used in combination.

  In the present invention, in order to control the gradation characteristics (gamma), it is preferable to use a plurality of types of photosensitive silver halide emulsions. The grain size, shape, halogen composition, and sensitizing dye adsorption so that each has a different sensitivity. By controlling the amount and the amount of the chemical sensitizer, it is possible to obtain a plurality of types of photosensitive silver halide emulsions. As the silver halide emulsion type to be used, 2 to 4 types, preferably 2 to 3 types, are preferably mixed or used as separate layers. The difference in sensitivity between the silver halide emulsions is preferably at least 0.2 LogE, and more preferably at least 0.3 LogE. “Log E” is an index representing sensitivity, and after exposure is performed through an optical wedge, the exposure amount (E) constituting the horizontal axis in a characteristic curve in which the vertical axis indicates density and the horizontal axis indicates exposure amount. ) Is a logarithmic value.

  As technologies relating to these, JP-A-57-119341, JP-A-53-106125, JP-A-47-3929, JP-A-48-55730, JP-A-46-5187, JP-A-50-73627 and JP-A-57-150841 are disclosed. Can be mentioned. The upper limit of the sensitivity difference is not particularly limited, but is a difference of about 1.0 LogE at maximum.

  In the silver salt photothermographic dry imaging material of the present invention, the non-photosensitive aliphatic carboxylic acid silver salt (hereinafter also simply referred to as organic silver salt) is relatively stable to light, but the exposed photocatalyst ( For example, a silver salt that forms a silver image when heated to 80 ° C. or higher in the presence of a photosensitive silver halide latent image) and a reducing agent. The organic silver salt may be any organic material containing a source capable of reducing silver ions. Examples of such non-photosensitive organic silver salts include paragraph numbers [0048] to [0049] of JP-A-6-130543, JP-A-8-314078, JP-A-9-127643, and JP-A-10-62899. Kaihei 10-94074, 10-94075, European Patent Publication No. 0,803,764A1, page 18, line 24 to page 19, line 37, European Patent Publication No. 0,962,812A1, No. 1,004,930A2, JP-A-11-349591, JP-A-2000-7683, JP-A-2000-72711, JP-A-2000-112057, JP-A-2000-155383, and the like. Silver salts of organic acids, particularly silver salts of long-chain aliphatic carboxylic acids having 10 to 30 carbon atoms, preferably 15 to 28 carbon atoms are preferred. Preferable examples of the organic silver salt are silver behenate, silver arachidate, silver stearate, and a mixture thereof. In the present invention, one feature is that the silver behenate content is 80 mol% or more. It is preferably 80 mol% or more and 100 mol% or less, more preferably 85 mol% or more and 100 mol% or less, and still more preferably 90 mol% or more and 100 mol% or less.

  The shape of the organic silver salt according to the present invention is preferably flake shaped particles having an aspect ratio of 1 or more and 9 or less. When the aspect ratio is in the range of 1 or more and 9 or less, the particles are not crushed during the preparation of the dispersion, and as a result, the image storability is improved, which is preferable.

  In the present invention, the scaly organic silver salt and the aspect ratio are defined as follows. The organic silver salt is observed with an electron microscope, the shape of the organic silver salt particle is approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped are a, b, and c from the shortest side (c may be the same as b). .) When calculating with the shorter numerical values a and b, x and y are obtained as follows.

x = b / a, y = c / b
Thus, x and y are obtained for about 200 particles, and when the average value x (average) is obtained, particles satisfying the relationship of 30 ≧ x (average) ≧ 1.5 are formed into flakes. Preferably, 30 ≧ x (average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. Incidentally, the needle shape is 1 ≦ x (average) <1.5. The average value y (average) is defined as the aspect ratio. The aspect ratio of the organic silver salt particles according to the present invention is preferably 1 or more, 9 or less, more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 3 or less.

  In the flake shaped particle, a can be regarded as a thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm or more and 0.23 μm or less, and more preferably 0.1 μm or more and 0.20 μm or less.

  In flake shaped particles, the equivalent spherical diameter / a of the particles is defined as the aspect ratio. The aspect ratio of the scaly particles in the present invention is preferably 1.1 or more and 30 or less. By setting the aspect ratio within such a range, aggregation is hardly caused in the heat-developable material, and image storage stability is improved. Becomes better. At this time, the aspect ratio is preferably 1.1 or more and 15 or less.

  The number average particle diameter of the non-photosensitive aliphatic carboxylic acid silver salt according to the present invention is preferably 0.01 μm or more and 0.60 μm or less, more preferably 0.20 μm or more, and 0.0. 50 μm or less. Thereby, it is difficult to cause aggregation in the heat-developable material, and the image storability is improved.

  The particle size distribution of the organic silver salt is preferably monodispersed. The monodispersion is preferably a percentage (coefficient of variation) of a value obtained by dividing the standard deviation of the volume weighted average diameter of the organic silver salt particles by the volume weighted average diameter, preferably 100% or less, more preferably 80% or less, and still more preferably 50 % Or less. As a measuring method, a method of obtaining from the particle size obtained by irradiating the organic silver salt particles dispersed in the dispersion medium with laser light and obtaining an autocorrelation function with respect to temporal change of the fluctuation of the scattered light is preferably used. .

  The organic silver salt particles according to the present invention are preferably prepared at a reaction temperature of 60 ° C. or less from the viewpoint of preparing particles having a low minimum concentration. Although the chemical | medical agent added, for example, organic acid alkali metal aqueous solution, may be temperature higher than 60 degreeC, it is preferable that the temperature of the reaction bath to which a reaction liquid is added is 60 degrees C or less. Furthermore, it is preferable that it is 50 degrees C or less, and it is especially preferable that it is 40 degrees C or less.

  The organic silver salt particles according to the present invention are prepared by reacting a solution containing silver ions such as silver nitrate with an organic acid alkali metal salt solution or suspension, which is 50% or more of the total added silver amount. The addition is preferably performed simultaneously with the addition of the organic acid alkali metal salt solution or suspension. The addition method includes a method of adding to the liquid surface of the reaction bath, a method of adding to the solution, and a method of adding to the closed mixing means. Any method may be used, but it is added to the closed mixing means. The method is preferred.

  The pH of the solution containing silver ions used in the present invention (for example, a silver nitrate aqueous solution) is preferably pH 1 or more and 6 or less, more preferably pH 1.5 or more and 4 or less. Acid and alkali can be added to the solution containing silver ions for pH adjustment, but the type of acid and alkali is not particularly limited.

  The organic silver salt according to the present invention may be ripened by raising the reaction temperature after the addition of a solution containing silver ions (for example, an aqueous silver nitrate solution) and / or an organic acid alkali metal salt solution or suspension is completed. I do not care. The aging in the present invention is considered to be different from the reaction temperature described above. During ripening, no solution containing silver ions and organic acid alkali metal salt solution or suspension is added. The aging is preferably performed at a reaction temperature of + 1 ° C. or higher and + 20 ° C. or lower, more preferably + 1 ° C. or higher and + 10 ° C. or lower. The aging time is preferably determined by trial and error.

  In the preparation of the organic silver salt according to the present invention, the addition of the organic acid alkali metal salt solution or suspension may be divided into two or more times and six times or less. By performing divided addition, for example, addition for improving photographic performance and addition for changing the hydrophilicity of the surface, etc., various functions can be imparted to the particles. The number of divided additions is preferably 2 or more and 4 or less. Here, since the organic silver salt is solidified unless the temperature is high, it is necessary to take into account, for example, that there are a plurality of addition lines for dividing, or a device such as a circulation method.

  In the preparation of the organic silver salt according to the present invention, after the addition of the solution containing 0.5 to 30 mol% of the total number of moles of the organic acid alkali metal salt solution or suspension containing silver ions is completed. These may be added alone. Preferably 3 mol% or more and 20 mol% or more may be added alone. This addition is preferably applied as a single divided addition. In the case of using a closed mixing means, this addition may be added to either the closed mixing means or the reaction tank, but it is preferable to add to the reaction tank. By carrying out this addition, the hydrophilicity of the surface of the organic silver salt particles can be increased. As a result, the film forming property of the heat developing material is improved and the film peeling is improved.

  Although the silver ion concentration of the solution containing silver ions used in the present invention (for example, an aqueous silver nitrate solution) is arbitrarily determined, the molar concentration is preferably 0.03 mol / L or more and 6.5 mol / L or less, more preferably 0.1 mol / L or more and 5 mol / L or less.

  In carrying out the present invention, in order to form organic silver salt particles, at least one of a solution containing silver ions, an organic acid alkali metal salt solution or suspension, and a solution prepared in advance in the reaction field, It is preferable that the organic solvent contains an organic solvent in an amount capable of becoming a substantially transparent solution, rather than the alkali metal salt of the organic acid being present in a string-like aggregate or micelle state. That is, by reacting a silver ion-containing solution and an organic acid alkali metal salt-containing solution in the presence of a water-miscible solvent, organic silver salt particles having excellent dispersibility and fluidity of fine organic silver salt particles A containing solution is obtained.

  The organic solvent used in the present invention is not particularly limited as long as it is water-soluble and has the above-mentioned properties. However, those that impede photographic performance are not preferred, preferably alcohol that can be mixed with water, acetone, A tertiary alcohol having 4 to 6 carbon atoms is preferred.

  Moreover, the alkali metal of the alkali metal salt of the organic acid used in the present invention is prepared by adding potassium hydroxide to the organic acid, that is, the alkali metal is potassium. This is preferable in that an organic silver salt particle-containing solution having excellent dispersibility and fluidity can be obtained. The alkali metal salt of the organic acid is prepared by adding potassium hydroxide to the organic acid. At this time, it is preferable to leave the unreacted organic acid with the alkali amount equal to or less than the equivalent of the organic acid. In this case, the amount of residual organic acid is 3 mol% or more and 50 mol% or less, preferably 3 mol% or more and 30 mol% or less with respect to the total organic acid. Moreover, after adding an alkali more than desired amount, you may prepare by adding acids, such as nitric acid and a sulfuric acid, and neutralizing an excess alkali content.

  Furthermore, the silver ion-containing solution and the organic acid alkali metal salt solution or suspension used in the present invention or the liquid in the closed mixing means to which both liquids are added include, for example, the general formula of JP-A-62-65035. A compound as shown in (1), a water-soluble group-containing N-heterocyclic compound as described in JP-A No. 62-150240, and an inorganic peroxidation as described in JP-A No. 50-101019 Products, sulfur compounds as described in JP-A-51-78319, disulfide compounds as described in JP-A-57-643, hydrogen peroxide, and the like can be added.

  In the organic acid alkali metal salt solution used in the present invention, the amount of the organic solvent is preferably 3% or more and 70% or less, more preferably 5% or more and 50% or less as the organic solvent volume with respect to the volume of moisture. It is. At this time, since the optimum organic solvent volume varies depending on the reaction temperature, the optimum amount can be determined by trial and error. The concentration of the alkali metal salt of the organic acid used in the present invention is 5% by mass or more and 50% by mass or less, preferably 7% by mass or more and 45% by mass or less, and more preferably 10% by mass as a mass ratio. As mentioned above, it is 40 mass% or less.

  For the purpose of keeping the temperature of the organic acid alkali metal salt solution or suspension added in the closed mixing means or the reaction vessel at a temperature necessary to avoid the phenomenon of crystallization and solidification of the organic acid alkali metal salt, 50 ° C or higher and 90 ° C or lower is preferable, 60 ° C or higher and 85 ° C or lower is more preferable, and 65 ° C or higher and 85 ° C or lower is most preferable. Further, in order to control the temperature of the reaction constant, it is preferable to control the reaction constant at a certain temperature selected from the above range. Accordingly, the rate at which a high-temperature organic acid alkali metal salt solution or suspension is rapidly cooled in a closed mixing means to precipitate in a microcrystalline state and the rate at which organic silver chloride is caused by reaction with a solution containing silver ions are preferred. And the crystal form, crystal size, and crystal size distribution of the organic silver salt can be preferably controlled. At the same time, the performance can be further improved as a heat-developable material, particularly as a heat-developable photosensitive material.

  The reaction vessel may contain a solvent in advance, and water is preferably used as the solvent put in advance, but a mixed solvent with an organic acid alkali metal salt solution or suspension is also preferably used.

  An aqueous medium-soluble dispersion aid can be added to the organic acid alkali metal salt solution or suspension, the solution containing silver ions, or the reaction solution. Any dispersing aid may be used as long as it can disperse the formed organic silver salt. A specific example is based on the description of the organic silver salt dispersion aid described below.

  In the method for preparing an organic silver salt, it is preferable to perform a desalting / dehydration step after the formation of the silver salt. The method is not particularly limited, and well-known and conventional means can be used. For example, known filtration methods such as centrifugal filtration, suction filtration, ultrafiltration, and flock-forming water washing by a coagulation method, and supernatant removal by centrifugal sedimentation are preferably used. Of these, the ultrafiltration method is preferable. The desalting / dehydration may be performed once or may be repeated a plurality of times. The addition and removal of water may be performed continuously or individually. The desalting / dehydration is performed so that the conductivity of the finally dehydrated water is preferably 300 μS / cm or less, more preferably 100 μS / cm or less, and most preferably 60 μS / cm or less. In this case, the lower limit of the conductivity is not particularly limited, but is usually about 5 μS / cm.

  As the ultrafiltration method, for example, a method used for desalting / concentration of a silver halide emulsion can be applied. Research Disclosure No. 10208 (1972), no. 13122 (1975) and no. 16351 (1977) and the like can be referred to. The pressure difference and flow rate that are important as operating conditions can be selected by referring to the characteristic curve described in Haruhiko Oya's “Membrane Utilization Technology Handbook”, Koshobo Publishing (1978), p275. In order to suppress particle aggregation and fogging, it is necessary to find the optimum conditions. There are two methods for replenishing the solvent that is lost due to membrane permeation: a constant volume method in which the solvent is continuously added and a batch method in which the solvent is intermittently added, but the desalting time is relatively short. The formula is preferred.

  As the solvent to be replenished, pure water obtained by ion exchange or distillation is used. In order to maintain the pH at a target value, a pH adjusting agent or the like may be mixed in pure water, or organic You may add directly to a silver salt dispersion.

  As for ultrafiltration membranes, flat plate type, spiral type, cylindrical type, hollow fiber type, hollow fiber type, etc., which are already incorporated as modules, include Asahi Kasei Co., Ltd., Daicel Chemical Co., Ltd., Toray Co., Ltd., and Nitto Co., Ltd. Although it is commercially available from Denko etc., a spiral type or a hollow fiber type is preferred from the viewpoint of the total membrane area and detergency. Moreover, it is preferable that the fraction molecular weight used as the parameter | index of the threshold value of the component which can permeate | transmit a film | membrane is 1/5 or less of the molecular weight of the polymer dispersing agent to be used.

  In the desalting by ultrafiltration in the present invention, prior to the treatment, it is preferable to disperse the liquid in advance until the particle size is about twice the volume-weighted average of the final particle size. The dispersing means may be any method such as a high pressure homogenizer or a microfluidizer described later.

  It is preferable to keep the liquid temperature low after the grain formation until the desalting operation proceeds. This is because when the organic solvent used for dissolving the alkali metal salt of the organic acid penetrates into the generated organic silver salt particles, the shearing field when passing through the liquid feeding operation or the ultrafiltration membrane, This is because silver nuclei are easily generated by the pressure field. For this reason, in this invention, ultrafiltration operation is performed, keeping the temperature of organic silver salt particle dispersion at 1-30 degreeC, Preferably it is 5-25 degreeC.

  Furthermore, in order to improve the coated surface state of the photothermographic material, especially the photothermographic material, a dispersant is further added to the desalted and dehydrated organic silver salt and redispersed to obtain a fine dispersion. Is preferred.

  Known methods and the like can be applied to the production and dispersion method of the organic silver salt used in the present invention. For example, the above-mentioned JP-A-8-234358, JP-A-10-62899, EP-A-0,803,763A1, EP-A-0,962,812A1, JP-A-11-349591, JP-A-2000. -7683, 2000-72711, 2000-53682, 2000-75437, 2000-86669, 2000-143578, 2000-178278, 2000-256254, 2001-163828 No. 2001-163890, No. 2001-163890, No. 2001-33907, No. 2000-305214, No. 2001-11081, No. 2000-344710, No. 2001-188313, No. 2001-83651, No. 2002-6442, No. 200 The -31,870 issue, or the like can be referred to.

  The method for finely dispersing the organic silver salt is carried out in the presence of a dispersion aid in the form of a known finer means (for example, a high speed mixer, a homogenizer, a high speed impact mill, a Banbury mixer, a homomixer, a kneader, a ball mill, a vibrating ball mill, a planetary planet. A ball mill, an attritor, a sand mill, a bead mill, a colloid mill, a jet mill, a roller mill, a tron mill, a high-speed stone mill, etc.) can be used for mechanical dispersion.

  In order to obtain a uniform organic silver salt solid dispersion having a monodisperse particle size distribution, a small particle size, and no agglomeration, it is large as long as the organic silver salt particles as an image forming medium are not damaged or heated. It is preferable to apply the force uniformly. For this purpose, a dispersion method is preferred in which a dispersion comprising an organic silver salt and a dispersant solution is converted into a high-speed flow and then the pressure is dropped. The dispersion medium in this case may be any solvent as long as the dispersion aid functions, but is preferably only water, and may contain an organic solvent as long as it is 20% by mass or less. Further, when a photosensitive silver salt is allowed to coexist at the time of dispersion, fogging is increased and sensitivity is remarkably lowered. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion.

  For example, “dispersion system rheology and dispersion technology” (Toshio Hataiuchi, Hiroki Arai, 1991, Shinyamasha Publishing Co., Ltd.) ), P357-403), "Progress of Chemical Engineering, Vol. 24" (Chemical Engineering Society, Tokai Branch, 1990, Tsuji Shoten, p184-185), JP-A-59-49832, US Pat. No. 4,533,254, Special Although described in detail in Kaihei 8-137044, JP-A-8-238848, JP-A-2-261525, JP-A-1-94933, etc., the redispersion method in the present invention contains at least an organic silver salt. After the dispersion is pressurized with a high-pressure pump or the like and fed into the pipe, it is passed through a narrow slit provided in the pipe, and then the dispersion is finely dispersed by causing a sudden pressure drop. It is preferable to be a method of performing.

  For high-pressure homogenizers, in general, (a) “shearing force” generated when the dispersoid passes through a narrow gap (about 75 μm to 350 μm) at high pressure and high speed, (b) liquid-liquid collision in a narrow space of high pressure, Alternatively, it is considered that uniform and efficient dispersion is performed by further increasing the cavitation force caused by the subsequent pressure drop without changing the impact force generated when the wall collides. In the old days, this type of dispersing device includes a gorin homogenizer. In this device, the liquid to be dispersed sent at a high pressure is converted into a high-speed flow in a narrow gap on the cylindrical surface, and this force is applied to the surrounding wall surface. Colliding and emulsifying / dispersing by the impact force. Examples of the liquid-liquid collision include a Y-type chamber of a microfluidizer, a spherical chamber using a spherical check valve as described in JP-A-8-103642, and the liquid-wall collision includes Examples include a Z-type chamber of a microfluidizer. In order to increase the dispersion efficiency, a device that has been devised such as making the high-speed flow part into a saw blade shape and increasing the number of collisions has been devised. Typical examples of such devices include Gorin homogenizers, microfluidizers manufactured by Microfluidics International Corporation, microfluidizers manufactured by Mizuho Industries, and nanomizers manufactured by Special Machine Industries. It is done. Also described in JP-A-8-238848, 8-103642, and U.S. Pat. No. 4,533,254.

  The organic silver salt can be dispersed in a desired particle size by adjusting the flow rate, the differential pressure during pressure drop and the number of treatments. From the viewpoint of photographic properties and particle size, the flow rate is 200 to 600 m / second, the pressure The pressure difference when dropping is preferably in the range of 9-30 MPa, more preferably the flow rate is in the range of 300-600 m / sec, and the pressure difference in the pressure drop is in the range of 15-30 MPa. The number of distributed processes can be selected as necessary. Usually, a range of 1 to 10 times is selected, but about 1 to 4 times is selected from the viewpoint of productivity. It is not preferable from the viewpoint of dispersibility and photographic properties to increase the temperature of such a dispersion under high pressure. At high temperatures exceeding 90 ° C., the particle size tends to increase and fog tends to increase. . Therefore, a cooling device is included in the process before the conversion to the high-pressure and high-speed flow, the process after the pressure drop, or both of these processes, and the temperature of such dispersion is in the range of 5 to 90 ° C. depending on the cooling process. It is preferable to be kept at a temperature of 5 to 80 ° C., particularly 5 to 65 ° C. In particular, it is effective to install the cooling device when dispersing at a high pressure in the range of 15 to 30 MPa. Depending on the required heat exchange amount, a cooling device using a static mixer in a double tube or triple tube, a multi-tube heat exchanger, a serpentine heat exchanger, or the like can be appropriately selected. In addition, in order to increase the efficiency of heat exchange, a suitable tube thickness, wall thickness, material, or the like may be selected in consideration of the operating pressure. The refrigerant used for the cooler is a heat exchanger such as 20 ° C. well water, 5-10 ° C. cold water treated with a refrigerator, or -30 ° C. ethylene glycol / water refrigerant, etc. can do.

  When the organic silver salt is made into solid fine particles using a dispersant, for example, polyacrylic acid, acrylic acid copolymer, maleic acid copolymer, maleic acid monoester copolymer, acryloylmethylpropane sulfonic acid Synthetic anionic polymers such as copolymers, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose, anionic polymers such as alginic acid and pectic acid, anions described in JP-A-52-92716, WO88 / 04794, etc. Surfactants, compounds described in Japanese Patent Application No. 7-350753, or known anionic, nonionic, cationic surfactants, and other known polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc. The polymer , Or it can be used a polymer compound existing in nature such as gelatin appropriately selected and. When a solvent is used as the dispersion medium, polyvinyl butyral, butylethyl cellulose, methacrylate copolymer, maleic anhydride ester copolymer, polystyrene, butadiene-styrene copolymer and the like are preferably used.

  Dispersing aid is a general method of mixing with organic silver salt powder or wet cake organic silver salt before dispersion, and sending it to the disperser as a slurry, but pre-mixed with organic silver salt It is good also as an organic silver salt powder or a wet cake by giving heat processing and the process by a solvent. The pH may be controlled with an appropriate pH adjusting agent before or after dispersion.

  In addition to mechanical dispersion, it may be coarsely dispersed in a solvent by controlling the pH, and then finely divided by changing the pH in the presence of a dispersion aid. At this time, you may use a fatty acid solvent as a solvent used for rough dispersion.

  In the present invention, it is possible to mix an organic silver salt aqueous dispersion and a photosensitive silver salt aqueous dispersion and use this to produce a heat-developable material, but the mixing ratio of the organic silver salt and the photosensitive silver salt is the purpose The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, more preferably 3 to 20 mol%, particularly preferably 5 to 15 mol%. When mixing, mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions is a means preferably used for adjusting photographic characteristics.

The organic silver salt according to the present invention can be used in a desired amount depending on the purpose, but the silver amount is preferably 0.1 to ² g / m ² , more preferably 0.5 to 1.8 g / m ² , still more preferably. Is 0.8 to 1.6 g / m ² .

  In the silver salt photothermographic dry imaging material of the present invention, it is one of the features that the photosensitive layer contains a silver ion reducing agent (hereinafter also simply referred to as a reducing agent). Although there is no restriction | limiting, in this invention, it is preferable that a reducing agent is at least 1 sort (s) chosen from the compound represented by the following general formula (A-1)-(A-3).

In General Formula (A-1), Z _A represents an atomic group necessary to form a 3- to 10-membered ring together with a carbon atom, and R _x represents a hydrogen atom or an alkyl group. R _A1 , R _A2 and Q ₀ each represent a substitutable group on the benzene ring, L _A represents a divalent linking group, ka represents an integer of 0 to 1, and na and ma are 0 to 2. Represents an integer. A plurality of R _A1 , R _A2 and Q ₀ may be the same or different.

In the general formula (A-2), R ₄₀ represents the following general formula (A). R _{43 to} R ₄₅ each represent a hydrogen atom or a substituent. When C in the general formula (A) does not form a ring with any of R _{43 to} R ₄₅ , R ₄₀ contains at least one optionally substituted ethylene group or an optionally substituted acetylene group. When C in the general formula (A) forms a ring with any of R _{43 to} R ₄₅ , R ₄₀ contains at least one optionally substituted ethylene group or an optionally substituted acetylene group outside the ring. . R ₄₁ , R ₄₁ ′, R ₄₂ , R ₄₂ ′, X ₄₁ , X ₄₁ ′ each represents a hydrogen atom or a substituent.

In general formula (A-3), R ₅₀ represents a hydrogen atom or a substituent. R ₅₁ , R ₅₁ ′, R ₅₂ , R ₅₂ ′, X ₅₁ , and X ₅₁ ′ each represent a hydrogen atom or a substituent. However, at least one of R ₅₁ , R ₅₁ ′, R ₅₂ , R ₅₂ ′, X ₅₁ and X ₅₁ ′ includes an optionally substituted ethylene group or an optionally substituted acetylene group.

In General Formula (A-1), Z _A represents an atomic group necessary to form a 3- to 10-membered ring together with a carbon atom, and Z _A represents a 3- to 10-membered non-aromatic ring or a 5- to 6-membered ring. It is preferably an aromatic ring, and more preferably a 3- to 10-membered non-aromatic ring. Specific examples of the ring include cyclopropyl, aziridyl, oxiranyl as a 3-membered ring, cyclobutyl, cyclobutenyl, oxetanyl, azetidinyl as a 4-membered ring, and cyclopentyl, cyclopentenyl, cyclopentadienyl, tetrahydrofuranyl, pyrrolidinyl as a 5-membered ring , Tetrahydrothienyl, 6-membered ring is cyclohexyl, cyclohexenyl, cyclohexadienyl, tetrahydropyranyl, pyranyl, piperidinyl, dioxanyl, tetrahydrothiopyranyl, norcaranyl, norpinanyl, norbornyl, 7-membered ring is cycloheptyl, cycloheptynyl, cyclohexanone Heptadienyl, 8-membered ring as cyclooctanyl, cyclooctenyl, cyclooctadienyl, cyclooctatrienyl, 9-membered ring as cyclononanyl Cyclononenyl, shea chrono Nagy enyl, cyclononatrienyl enyl, as the 10-membered ring cyclooctyl, Shikurodekeniru, cycloalkyl decadienyl include the group such as cyclopropyl tetradecatrienyl.

  Preferably it is a 3-6 membered ring, More preferably, it is a 5-6 membered ring, Most preferably, it is a 6 membered ring, Among these, the hydrocarbon ring which does not contain a hetero atom is preferable. The ring may form a spiro bond with another ring through a spiro atom, or may be condensed in any way with another ring including an aromatic ring. Moreover, it can have an arbitrary substituent on the ring. The hydrocarbon ring is particularly preferably a hydrocarbon ring containing an alkenyl structure or alkynyl structure containing —C═C— or —C≡C—.

  Specific examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an iso-pentyl group, 2-ethyl-hexyl group, octyl group, decyl group, etc.), cycloalkyl group (for example, cyclohexyl group, cycloheptyl group, etc.), alkenyl group (for example, ethenyl-2-propenyl group, 3-butenyl group, 1-methyl) -3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl group, etc.), cycloalkenyl group (eg 1-cycloalkenyl group, 2-cycloalkenyl group etc.), alkynyl group (eg ethynyl group, 1-propynyl group etc.), alkoxy group (eg methoxy group, ethoxy group, propoxy group etc.), alkylcarbonyloxy group For example, acetyloxy group etc.), alkylthio group (eg methylthio group, trifluoromethylthio group etc.), carboxyl group, alkylcarbonylamino group (eg acetylamino group etc.), ureido group (eg methylaminocarbonylamino group etc.) ), Alkylsulfonylamino groups (for example, methanesulfonylamino group, etc.), alkylsulfonyl groups (for example, methanesulfonyl group, trifluoromethanesulfonyl group, etc.), carbamoyl groups (for example, carbamoyl group, N, N-dimethylcarbamoyl group, N -Morpholinocarbonyl group, etc.), sulfamoyl group (sulfamoyl group, N, N-dimethylsulfamoyl group, morpholinosulfamoyl group, etc.), trifluoromethyl group, hydroxyl group, nitro group, cyano group, alkylsulfone Group (for example, methanesulfonamide group, butanesulfonamide group, etc.), alkylamino group (for example, amino group, N, N-dimethylamino group, N, N-diethylamino group, etc.), sulfo group, phosphono group, sulfite Group, sulfino group, alkylsulfonylaminocarbonyl group (eg methanesulfonylaminocarbonyl group, ethanesulfonylaminocarbonyl group etc.), alkylcarbonylaminosulfonyl group (eg acetamidosulfonyl group, methoxyacetamidosulfonyl group etc.), alkynylamino ++ carbonyl Groups (for example, acetamidocarbonyl group, methoxyacetamidocarbonyl group, etc.), alkylsulfinylaminocarbonyl groups (for example, methanesulfinylaminocarbonyl group, ethanesulfinylaminocarbonyl group) And the like. Moreover, when there are two or more substituents, they may be the same or different. Particularly preferred substituents are alkyl groups.

Next, the case where Z _A is a 5- or 6-membered aromatic cyclic group will be described. The aromatic carbocycle may be monocyclic or condensed, and preferably includes a monocyclic or bicyclic aromatic carbocyclic ring having 6 to 30 carbon atoms (for example, a benzene ring, a naphthalene ring, etc.). A benzene ring is preferably used. The aromatic heterocycle is preferably a 5- to 6-membered aromatic heterocycle which may have a condensed ring. More preferably, it is a 5-membered aromatic heterocycle optionally having a condensed ring. Such heterocycles are preferably imidazole, pyrazole, thiophene, furan, pyrrole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline Quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, indolenine, tetrazaindene, more preferably imidazole, pyrazole, thiophene, furan, pyrrole, Triazole, thiadiazole, tetrazole, thiazole, benzimidazole, benzothiazole, especially Mashiku thiophene, furan, thiazole. The ring may be condensed in any manner with other rings including an aromatic ring. Moreover, it can have an arbitrary substituent on the ring. Examples of the substituent include the same substituents as those described above on the 3- to 10-membered non-aromatic cyclic group. When Z _A is a 5- to 6-membered aromatic cyclic group, it is most preferable that Z _A is a 5-membered aromatic heterocyclic group.

R _A1 and R _A2 represent a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. Specifically, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, pentyl group, iso-pentyl group, 2-ethyl-hexyl group, octyl group, decyl group, cyclohexyl group, cycloheptyl. Group, 1-methylcyclohexyl group, ethenyl-2-propenyl group, 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl group, 1-cycloalkenyl group, 2 -A cycloalkenyl group, an ethynyl group, a 1-propynyl group, etc. are mentioned. R _A1 is preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a cyclohexyl group, a 1-methylcyclohexyl group, or the like. More preferred are a methyl group, a t-butyl group, and a 1-methylcyclohexyl group, and most preferred are a t-butyl group and a 1-methylcyclohexyl group. R _A2 is preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a 2-hydroxyethyl group, or the like. More preferably, they are a methyl group and 2-hydroxyethyl group. Specific examples of the aryl group represented by R _A1 and R _A2 include a phenyl group, a naphthyl group, and an anthranyl group. Specific examples of the heterocyclic group represented by R _A1 and R _A2 include pyridine group, quinoline group, isoquinoline group, imidazole group, pyrazole group, triazole group, oxazole group, thiazole group, oxadiazole group, thiadiazole group, and tetrazole. And non-aromatic heterocyclic groups such as an aromatic heterocyclic group such as a group, piperidino group, morpholino group, tetrahydrofuryl group, tetrahydrothienyl group and tetrahydropyranyl group. These groups may further have a substituent, and examples of the substituent include the above-described substituents on the ring.

In the most preferred combination of R _A1 and R _A2 , R _A1 is a tertiary alkyl group (eg, t-butyl group, 1-methylcyclohexyl group, etc.), and R _A2 is a primary alkyl group (eg, methyl group, 2- Hydroxyethyl group, etc.).

R _X represents a hydrogen atom or an alkyl group, and specifically, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, pentyl group, iso-pentyl group, 2-ethyl-hexyl group, octyl group, decyl group, cyclohexyl group, cycloheptyl. Group, 1-methylcyclohexyl group, ethenyl-2-propenyl group, 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl group, 1-cycloalkenyl group, 2 -A cycloalkenyl group, an ethynyl group, a 1-propynyl group, etc. are mentioned. More preferably, a methyl group, an ethyl group, an isopropyl group, etc. are mentioned. Preferably R _X is a hydrogen atom.

Q ₀ represents a substitutable group on the benzene ring, specifically, an alkyl group having 1 to 25 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group). Cyclohexyl group, etc.), halogenated alkyl group (trifluoromethyl group, perfluorooctyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group etc.), alkynyl group (propargyl group etc.), glycidyl group, acrylate group, methacrylate Group, aryl group (phenyl group etc.), heterocyclic group (pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group, sriphoranyl group, piperidinyl group, Pyrazolyl group, tetrazolyl group, etc.), halogen atom (chlorine source) , Bromine atom, iodine atom, fluorine atom, etc.), alkoxy group (methoxy group, ethoxy group, propyloxy group, pentyloxy group, cyclopentyloxy group, hexyloxy group, cyclohexyloxy group, etc.), aryloxy group (phenoxy group, etc.) ), Alkoxycarbonyl group (methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.), aryloxycarbonyl group (phenyloxycarbonyl group, etc.), sulfonamide group (methanesulfonamide group, ethanesulfonamide group, butane) Sulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group, etc.), sulfamoyl group (aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylamino) Nosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, phenylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), urethane group (methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, phenylureido group, 2-pyridylureido group, etc.), acyl group (acetyl group, propionyl group, butanoyl group, hexanoyl group, cyclohexanoyl group, benzoyl group, pyridinoyl group, etc.), carbamoyl group (aminocarbonyl group, methylaminocarbonyl group, dimethylamino) Carbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), amide group (acetate) Amide group, propionamide group, butanamide group, hexaneamide group, benzamide group, etc.), sulfonyl group (methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, phenylsulfonyl group, 2-pyridylsulfonyl group, etc.), Amino group (amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, anilino group, 2-pyridylamino group, etc.), cyano group, nitro group, sulfo group, carboxyl group, hydroxyl group, oxamoyl group, etc. Can be mentioned. These groups may be further substituted with these groups. na and ma represent an integer of 0 to 2, and most preferably na and ma are 0.

L _A represents a divalent linking group, preferably an alkylene group such as methylene, ethylene, propylene, and preferably has 1 to 20 carbon atoms, more preferably 1 to 5 carbon atoms. ka represents an integer of 0 to 1, but is most preferably ka = 0.

  Next, the reducing agent represented by the general formula (A-2) or the general formula (A-3) according to the present invention will be described.

In the general formula (A-2), R ₄₀ represents the general formula (A), but R _{43 to} R ₄₅ represent a hydrogen atom or a substituent. Examples of the substituent represented by R _{43 to} R ₄₅ include an alkyl group (methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, sec-butyl, t-butyl, cyclohexyl, 1-methyl-cyclohexyl, etc. Each group), alkenyl group (vinyl, propenyl, butenyl, pentenyl, isohexenyl, cyclohexenyl, butenylidene, isopentylidene, etc.), alkynyl group (ethynyl, propynylidene, etc.), aryl group (phenyl, naphthyl, etc.) Etc.), heterocyclic groups (furyl, thienyl, pyridyl, tetrahydrofuranyl, etc. groups), halogen, hydroxyl, alkoxy, aryloxy, acyloxy, sulfonyloxy, nitro, amino, acylamino, sulfonylamino, Sulfonyl, carbox Ci, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, sulfamoyl, cyano, sulfo and the like.

When C in the general formula (A) does not form a ring with any of R _{43 to} R ₄₅ , R ₄₀ represents at least one optionally substituted ethylene group (2,6-dimethyl-5-heptenyl, 1, 5-dimethyl-4-hexenyl etc.) or an acetylene group (1-propynyl etc.) which may be substituted.

When C in the general formula (A) forms a ring (phenyl, naphthyl, furyl, thienyl, pyridyl, cyclohexyl, cyclohexenyl, etc.) with any of R _{43 to} R ₄₅ , R ₄₀ is at least one outside of the ring. It includes an optionally substituted ethylene group (vinyl, propenyl, acryloxy, methacryloxy, etc.) or an optionally substituted acetylene group (ethynyl, acetylenecarbonyloxy, etc.).

R ₄₁ , R ₄₁ ′, R ₄₂ , R ₄₂ ′, X ₄₁ , and X ₄₁ ′ each represent a hydrogen atom or a substituent, and the substituent is the same as the substituent described in the description of R _{43 to} R _45. Group.

R ₄₁ , R ₄₁ ′, R ₄₂ , and R ₄₂ ′ are preferably alkyl groups, and specific examples thereof include the same groups as the alkyl groups exemplified in the description of R _{43 to} R ₄₅ .

In the general formula (A-3), R ₅₀ represents a hydrogen atom or a substituent, and the substituent is the same as the substituent described in the description of R _{43 to} R _{45 in} the general formula (A-2). Groups. R ₅₀ is preferably a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, more preferably a hydrogen atom or an alkyl group.

R ₅₁ , R ₅₁ ′, R ₅₂ , R ₅₂ ′, X ₅₁ , and X ₅₁ ′ each represent a hydrogen atom or a substituent, and examples of the substituent include R _{43 to} R _{45 in} formula (A-2). And the same groups as the substituents mentioned in the description of.

R ₅₁ , R ₅₁ ′, R ₅₂ , and R ₅₂ ′ are preferably an alkyl group, an alkenyl group, an alkynyl group, and the like, and specifically, an alkyl group, an alkenyl group, and an alkynyl group mentioned in the description of R _{43 to} R _45. The same group as the example of group is mentioned.

Provided that at least one of R ₅₁ , R ₅₁ ′, R ₅₂ , R ₅₂ ′, X ₅₁ , and X ₅₁ ′ may be substituted ethylene group (vinyl, allyl, methacryloxymethyl, etc.) or acetylene group that may be substituted (Ethynyl, propargyl, propargyloxycarbonyloxymethyl, etc.).

  In this invention, it is preferable to use together the compound represented by the said general formula (A-1), and the compound represented by the following general formula (A-4). The combined ratio is [mass of general formula (A-1)]: [mass of general formula (A-4)] = 95: 5 to 55:45, more preferably 90:10 to 60:40. .

In the general formula (A-4), X ₆₁ represents a chalcogen atom or CHR ₆₁ . The chalcogen atom is sulfur, selenium or tellurium, preferably a sulfur atom. R ₆₁ in CHR ₆₁ represents a hydrogen atom, a halogen atom, an alkyl group, the halogen atom, e.g., fluorine atom, chlorine atom, bromine atom, substituted as the alkyl group, or unsubstituted carbon atoms 1 Twenty alkyl groups are preferred. Specific examples of the alkyl group include, for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, heptyl group, vinyl group, allyl group, butenyl group, hexadienyl group, ethenyl-2-propenyl group, and 3-butenyl. Group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl group and the like.

  These groups may further have a substituent, and the substituent described in general formula (A-1) can be used as the substituent. Moreover, when there are two or more substituents, they may be the same or different.

R ₆₃ represents an alkyl group, which may be the same or different, but at least one is a secondary or tertiary alkyl group. The alkyl group is preferably a substituted or unsubstituted one having 1 to 20 carbon atoms, specifically a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, t-amyl group. , T-octyl group, cyclohexyl group, cyclopentyl group, 1-methylcyclohexyl group, 1-methylcyclopropyl group and the like.

The substituent of the alkyl group is not particularly limited. For example, an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, and an acyl group. Carbamoyl group, ester group, halogen atom and the like. Further, a saturated ring may be formed with (Q ₀ ) _na and (Q ₀ ) _ma . R ₆₃ is preferably a secondary or tertiary alkyl group, and preferably has 2 to 20 carbon atoms. A tertiary alkyl group is more preferable. More preferred are a t-butyl group, a t-amyl group, and a 1-methylcyclohexyl group, and most preferred is a 1-methylcyclohexyl group.

R ₆₄ represents a hydrogen atom or a group that can be substituted on the benzene ring. Examples of the group that can be substituted on the benzene ring include a halogen atom such as a fluorine atom, chlorine atom, bromine atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, amino group, acyl group, Examples include acyloxy group, acylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, sulfonyl group, alkylsulfonyl group, sulfinyl group, cyano group, and heterocyclic group. A plurality of R ₆₃ and R ₆₄ may be the same or different.

R ₆₄ preferably has 1 to 5 carbon atoms, more preferably 1 to 2 carbon atoms. These groups may further have a substituent, and the substituent described in general formula (A-1) can be used as the substituent. R ₆₄ is preferably an alkyl group having 1 to 20 carbon atoms, and most preferably a methyl group.

Q ₀ , na, and ma have the same meaning as in general formula (A-1). Q ₀ may form a saturated ring with R ₆₃ and R ₆₄ . Q ₀ is preferably a hydrogen atom, a halogen atom or an alkyl group, more preferably a hydrogen atom.

  Specific examples of the compounds represented by the general formulas (A-1) to (A-4) according to the present invention described above are described in paragraph numbers 0197 to 0209 of Japanese Patent Application No. 2004-289721 ( 1-1) to (1-94).

  The reducing agent contained in the photothermographic material is for reducing the organic silver salt to form a silver image. Examples of the reducing agent that can be used in combination with the reducing agent of the present invention include, for example, U.S. Pat. Nos. 3,770,448, 3,773,512, 3,593,863, RD17029 and 29963. -119372, JP-A-2002-62616, and the like.

The amount of the reducing agent including the compounds represented by the general formulas (A-1) to (A-4) is preferably 1 × 10 ⁻² to 10 mol, particularly preferably 1 ×, per 1 mol of silver. 10 ^{−2 to} 1.5 mol.

  Next, components other than those described above in the silver salt photothermographic dry imaging material of the present invention will be described.

  Regarding the color tone of an output image for medical diagnosis such as a conventional X-ray photographic film, it is said that a cold tone image tone is easier for a reader to obtain a more accurate diagnostic observation result of a recorded image. Here, a cool image tone is a pure black tone or a bluish black tone with a black image, and a warm image tone is a black tone with a brown tone. However, in order to allow a more precise quantitative discussion, the following explanation is based on the expression recommended by the International Commission on Illumination (CIE).

The terms “more cold” and “more warm” regarding the color tone can be expressed by the hue angle hab at the minimum density Dmin and the optical density D = 1.0. That is, the hue angle hab uses the color coordinates a ^* and b ^* of the L ^* a ^* b ^* color space, which is a color space having a perceptually almost uniform rate recommended by the International Commission on Illumination (CIE) in 1976. The following formula is used.

hab = tan ⁻¹ (b ^* / a ^* )
On the other hand, u ^* , v ^* or a ^* , b ^* in the CIE 1976 (L ^* u ^* v ^* ) color space or (L ^* a ^* b ^* ) color space near an optical density of 1.0 is set to a specific numerical value. It is known that a diagnostic image having a preferable visual color tone can be obtained by adjustment, and is described in, for example, Japanese Patent Application Laid-Open No. 2000-29164.

The silver salt photothermographic dry imaging material of the present invention has been further intensively studied, and as a result, the horizontal axis is u ^* or a ^{* in the} CIE 1976 (L ^* u ^* v ^* ) color space or (L ^* a ^* b ^* ) color space ^. When a linear regression line is created by plotting u ^* , v ^* or a ^* , b ^* at various photographic densities on a graph with the vertical axis representing v ^* or b ^* , the linear regression line is specified. By adjusting to this range, it was found that it has a diagnostic property equal to or higher than that of conventional wet silver salt photosensitive materials.

That is, the silver salt photothermographic dry imaging material was measured for the optical density of 0.5, 1.0, 1.5 and the lowest optical density of the silver image obtained after the heat development processing, and CIE 1976 (L ^* u ^* v ^* ) The linear regression line coefficient of determination (multiple determination) created by arranging u ^* and v ^* at the above optical densities on two-dimensional coordinates where the horizontal axis of the color space is u ^* and the vertical axis is v ^*. ) R ² is preferably 0.998 or more and 1.000 or less.

Furthermore, it is preferable that the v ^* value of the intersection with the vertical axis of the linear regression line is −5 or more and 5 or less, and the slope (v ^* / u ^* ) is 0.7 or more and 2.5 or less. .

In the following, an example of a method for creating the above-described linear regression line, that is, a method for measuring u ^* and v ^* in the CIE 1976 color space will be described.

A four-stage wedge sample including an unexposed portion and optical densities of 0.5, 1.0, and 1.5 is prepared using a heat development apparatus. Each wedge density part thus produced is measured with a spectrocolorimeter (example: CM-3600d; manufactured by Minolta) to calculate u ^* and v ^* . The measurement conditions at that time are F7 light source as the light source, the viewing angle is 10 °, and the measurement is performed in the transmission measurement mode. The horizontal axis u ^*, the vertical axis were measured v ^* and the on the graph u ^*, v ^* a plot to determine the coefficient determined the linear regression line (multiple determination) R ^2, obtaining the intercept and slope.

  Next, a specific method for obtaining a linear regression line having the above characteristics will be described.

  In the present invention, developed silver is prepared by adjusting the addition amount of the compounds such as the following toning agents, reducing agents, silver halide grains and aliphatic carboxylic acid silver which are directly and indirectly involved in the development reaction process. The shape can be optimized to obtain a preferable color tone. For example, when the developed silver shape is dendritic, it becomes a bluish direction, and when it is a filament shape, it becomes a yellowish direction. That is, it can be adjusted in consideration of the tendency of the developed silver shape.

  It is desirable to use a toning agent in the silver salt photothermographic dry imaging material of the present invention. Examples of suitable toning agents that can be used include Research Disclosure (hereinafter abbreviated as RD) No. 17029, U.S. Pat. Nos. 4,123,282, 3,994,732, and 3,846. 136 and 4,021,249. A particularly preferable colorant is a combination of phthalazinone or phthalazine with phthalic acids and phthalic anhydrides.

  In particular, in the present invention, carboxylic acids such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, benzoic acid, 4-methylbenzoic acid, 4-nitrobenzoic acid and pentachlorobenzoic acid are used. It is preferable to contain in a non-photosensitive layer adjacent to the photosensitive layer. More preferably, it is contained in the non-photosensitive layer opposite to the support with respect to the photosensitive layer.

  The amount of the toning agent contained in the non-photosensitive layer is preferably 0.005 to 0.20 mol / Ag mol, and more preferably 0.01 to 0.10 mol / Ag mol.

  In addition to such a toning agent, the color tone can also be adjusted by using a coupler disclosed in JP-A-11-288057, EP1134611A2 and the like and a leuco dye described in detail below. In particular, it is preferable to use a leuco dye for fine adjustment of the color tone.

  The leuco dye may be any colorless or slightly colored compound that is oxidized to a colored form when heated at a temperature of about 80-200 ° C. for about 0.5-30 seconds, and is oxidized by silver ions to form a dye. Any leuco dye that forms can be used in the present invention. Compounds that are pH sensitive and can be oxidized to a colored state are useful. Representative leuco dyes suitable for use in the present invention are not particularly limited. For example, biphenol leuco dyes, phenol leuco dyes, indoalilin leuco dyes, acrylated azine leuco dyes, phenoxazine leuco dyes, Examples include diazine leuco dyes and phenothiazine leuco dyes. Also useful are U.S. Pat. Nos. 3,445,234, 3,846,136, 3,994,732, 4,021,249, 4,021, Nos. 250, 4,022,617, 4,123,282, 4,368,247, 4,461,681, and JP-A-50-36110 No. 5, JP-A-59-206831, JP-A-5-204087, JP-A-11-231460, JP-A-2002-169249, JP-A-2002-236334, and the like. . In order to adjust to a predetermined color tone, it is preferable to use leuco dyes of various colors singly or in combination of a plurality of types. In the present invention, the color tone is excessively yellowish with the use of a highly active reducing agent, or the image is excessively high at a high density portion of 2.0 or more by using fine silver halide. In order to prevent redness from occurring, it is preferable to use a leuco dye that develops cyan. However, in order to finely adjust the color tone, it is preferable to use a leuco dye that develops yellow and cyan.

  The leuco dye is preferably any colorless or slightly colored compound that is oxidized to a colored form when heated at a temperature of about 80-200 ° C. for about 0.5-30 seconds, and is oxidized by silver ions. Any leuco dye that forms a pigment can be used. Also useful are compounds that are pH sensitive and can be oxidized to a colored state.

  Representative leuco dyes suitable for use in the present invention are not particularly limited, for example, biphenol leuco dyes, phenol leuco dyes, indoaniline leuco dyes, acrylated azine leuco dyes, phenoxazine leuco dyes, phenodiazine leuco dyes. And dyes and phenothiazine leuco dyes. Also useful are US Pat. Nos. 3,445,234, 3,846,136, 3,994,732, 4,021,249, 4,021,250, 4,022,617, 4,123,282, 4,368,247, 4,461,681, and JP-A-50-36110, 59-26831, These are leuco dyes disclosed in JP-A-5-204087, JP-A-11-231460, JP-A-2002-169249, and JP-A-2002-236334.

  In order to adjust to a predetermined color tone, it is preferable to use leuco dyes of various colors singly or in combination of a plurality of types. In the present invention, the use of a highly active reducing agent changes the color tone (especially yellowishness) depending on the amount and ratio of use, and the use of fine grain silver halide results in a concentration of 2. In order to prevent the image from becoming excessively reddish at a high density portion of 0 or more, it is preferable to use a leuco dye that develops yellow and cyan colors and adjust the amount of use.

  The color density is preferably adjusted appropriately in relation to the color tone of the developed silver itself. In the present invention, color is developed so as to have a reflection optical density of 0.01 to 0.05 or a transmission optical density of 0.005 to 0.50, and the color tone is adjusted so that an image in the above preferred color tone range is obtained. It is preferable.

  In the present invention, the sum of the maximum densities at the maximum absorption wavelength of the dye image formed with the leuco dye is preferably 0.01 or more and 0.50 or less, more preferably 0.02 or more and 0.30 or less, particularly preferably. Is preferably colored so as to have 0.03 or more and 0.10 or less.

(Yellow coloring leuco dye)
In the present invention, a color image forming agent that increases the absorbance at 360 to 450 nm when oxidized is particularly preferably used as a yellow color-forming leuco dye. Color image formation represented by the following general formula (YA) It is preferable that it is an agent.

In the formula, R ₁₁ represents a substituted or unsubstituted alkyl group, R ₁₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group or an acylamino group, respectively, and R ₁₁ and R ₁₂ are 2-hydroxyphenylmethyl groups. There is never. R ₁₃ represents a hydrogen atom or a substituted or unsubstituted alkyl group, and R ₁₄ represents a substituent that can be substituted on the benzene ring.

  Hereinafter, the compound of the general formula (YA) will be described in detail.

In General Formula (YA), R ₁₁ represents a substituted or unsubstituted alkyl group. When R ₁₂ is a substituent other than a hydrogen atom, R ₁₁ represents an alkyl group. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms and may have a substituent.

Specifically, methyl, ethyl, butyl, octyl, i-propyl, t-butyl, t-octyl, t-pentyl, sec-butyl, cyclohexyl, 1-methyl-cyclohexyl and the like are preferable, and steric rather than i-propyl. Are preferably large groups (i-propyl, i-nonyl, t-butyl, t-amyl, t-octyl, cyclohexyl, 1-methyl-cyclohexyl, adamantyl, etc.), among which secondary or tertiary alkyl Group is preferable, and tertiary alkyl groups such as t-butyl, t-octyl, and t-pentyl are particularly preferable. Examples of the substituent that R ₁₁ may have include a halogen atom, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamido group, an acyloxy group, an oxycarbonyl group, and a carbamoyl group. , Sulfamoyl group, sulfonyl group, phosphoryl group and the like.

R ₁₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group or an acylamino group, respectively. The alkyl group represented by R ₁₂ is preferably an alkyl group having 1 to 30 carbon atoms, and the acylamino group is preferably an acylamino group having 1 to 30 carbon atoms. Among these, the description of the alkyl group is the same as R ₁₁ described above.

The acylamino group represented by R ₁₂ may be unsubstituted or substituted, and specific examples include an acetylamino group, an alkoxyacetylamino group, and an aryloxyacetylamino group. R ₁₂ is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, and specific examples include methyl, i-propyl, and t-butyl. R ₁₁ and R ₁₂ are not 2-hydroxyphenylmethyl groups.

R ₁₃ represents a hydrogen atom or a substituted or unsubstituted alkyl group. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, and the description of the alkyl group is the same as that for R ₁₁ . R ₁₃ is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, and specific examples include methyl, i-propyl, t-butyl and the like. Further, it is preferable either R _12, R ₁₃ is a hydrogen atom.

R ₁₄ represents a group capable of substituting on the benzene ring, for example, specifically an alkyl group having 1 to 25 carbon atoms (methyl, ethyl, propyl, i-propyl, t-butyl, pentyl, hexyl, cyclohexyl, etc.), Halogenated alkyl groups (trifluoromethyl, perfluorooctyl, etc.), cycloalkyl groups (cyclohexyl, cyclopentyl, etc.), alkynyl groups (propargyl etc.), glycidyl groups, acrylate groups, methacrylate groups, aryl groups (phenyl etc.), heterocyclic rings Groups (pyridyl, thiazolyl, oxazolyl, imidazolyl, furyl, pyrrolyl, pyrazinyl, pyrimidinyl, pyridazinyl, selenazolyl, sriphoranyl, piperidinyl, pyrazolyl, tetrazolyl, etc.), halogen atoms (chlorine, bromine, iodine, fluorine), alkoxy groups (methoxy, ethoxy) Propyloxy, pentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, etc.), aryloxy groups (phenoxy, etc.), alkoxycarbonyl groups (methyloxycarbonyl, ethyloxycarbonyl, butyloxycarbonyl, etc.), aryloxycarbonyl groups (phenyloxy) Carbonyl, etc.), sulfonamide groups (methanesulfonamide, ethanesulfonamide, butanesulfonamide, hexanesulfonamide group, cyclohexanesulfonamide, benzenesulfonamide, etc.), sulfamoyl groups (aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl, butyl) Aminosulfonyl, hexylaminosulfonyl, cyclohexylaminosulfonyl, phenylaminosulfonyl, 2-pyridyla Nosulfonyl, etc.), urethane groups (methylureido, ethylureido, pentylureido, cyclohexylureido, phenylureido, 2-pyridylureido, etc.), acyl groups (acetyl, propionyl, butanoyl, hexanoyl, cyclohexanoyl, benzoyl, pyridinoyl, etc.) Carbamoyl group (aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, propylaminocarbonyl, pentylaminocarbonyl group, cyclohexylaminocarbonyl, phenylaminocarbonyl, 2-pyridylaminocarbonyl), amide group (acetamide, propionamide, butanamide, hexanamide) , Benzamide, etc.), sulfonyl group (methylsulfonyl, ethylsulfonyl, butylsulfonyl, cyclohexylsulfoni) , Phenylsulfonyl, 2-pyridylsulfonyl, etc.), amino group (amino, ethylamino, dimethylamino, butylamino, cyclopentylamino, anilino, 2-pyridylamino, etc.), cyano group, nitro group, sulfo group, carboxyl group, hydroxyl group Group, oxamoyl group and the like. R ₁₄ is preferably a substituted or unsubstituted alkyl group having 1 to 25 carbon atoms or an oxycarbonyl group having 2 to 30 carbon atoms, and more preferably an alkyl group having 1 to 25 carbon atoms. Examples of the substituent of the alkyl group include an aryl group, an amino group, an alkoxy group, an oxycarbonyl group, an acylamino group, an acyloxy group, an imide group, and a ureido group, and more preferable examples include an aryl group, an amino group, an oxycarbonyl group, and an alkoxy group. preferable. These alkyl group substituents may be further substituted with these substituents.

  Next, among the compounds represented by the general formula (YA), the bisphenol compound represented by the following general formula (YB), which is particularly preferably used in the present invention, will be described.

In the formula, Z represents —S— or —C (R ₂₁ ) (R ₂₁ ′) —, and R ₂₁ and R ₂₁ ′ each represents a hydrogen atom or a substituent. Examples of the substituent represented by R ₂₁ and R ₂₁ ′ include the same groups as those described in the description of R _{14 in} the general formula (YA). R ₂₁ and R ₂₁ ′ are preferably a hydrogen atom or an alkyl group.

R ₂₂ , R ₂₃ , R ₂₂ ′ and R ₂₃ ′ each represent a substituent, and examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkyl group (for example, a methyl group, an ethyl group, Group, propyl group, butyl group, dodecyl group etc.), hydroxyl group, cyano group, nitro group, alkoxy group (eg methoxy group, ethoxy group etc.), alkylsulfonamide group (eg methylsulfonamide group, octylsulfonamide group) Etc.), arylsulfonamide groups (eg, phenylsulfonamide groups, naphthylsulfonamide groups, etc.), alkylsulfamoyl groups (eg, butylsulfamoyl groups, etc.), arylsulfamoyl groups (eg, phenylsulfamoyl groups) Etc.), alkyloxycarbonyl groups (for example, methoxycarbonyl groups, etc.), aryloxycarboni Group (for example, phenyloxycarbonyl group), aminosulfonamide group, acylamino group, carbamoyl group, sulfonyl group, sulfinyl group, sulfoxy group, sulfo group, aryloxy group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, An aminocarbonyl group etc. are mentioned.

R ₂₂ , R ₂₃ , R ₂₂ ′ and R ₂₃ ′ are preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, but an alkyl group is more preferable. Examples of the substituent on the alkyl group include the same groups as those described in the description of the substituent in R ₂₂ , R ₂₃ , R ₂₂ ′ and R ₂₃ ′.

R ₂₂ , R ₂₃ , R ₂₂ ′ and R ₂₃ ′ are more preferably tertiary alkyl groups such as t-butyl, t-pentyl, t-octyl and 1-methyl-cyclohexyl.

R ₂₄ and R ₂₄ ′ each represents a hydrogen atom or a substituent, and examples of the substituent include the same groups as those described in the description of R ₂₂ , R ₂₃ , R ₂₂ ′ and R ₂₃ ′. .

  Examples of the compounds represented by the general formulas (YA) and (YB) include compounds (1) to (40) described in paragraphs “0032” to “0038” of JP-A No. 2002-169249, European Patent No. 1 , 211,093 specification, the compounds (ITS-1) to (ITS-12) described in paragraph [0026].

  Although the specific example of the bisphenol compound represented by general formula (YA) and (YB) below is shown, this invention is not limited to these.

  The addition amount of the compound of the general formula (YA) (including hindered phenol compounds and compounds of the general formula (YB)) is usually 0.00001 to 0.01 mol, preferably 0. 0005 to 0.01 mol, more preferably 0.001 to 0.008 mol.

  The addition ratio of the yellow color-forming leuco dye to the sum of the reducing agents is preferably 0.001 to 0.2, and more preferably 0.005 to 0.1, in terms of molar ratio.

(Cyan coloring leuco dye)
The cyan color-forming leuco dye preferably used in the present invention will be described. The leuco dye is preferably any colorless or slightly colored compound that is oxidized to a colored form when heated at a temperature of about 80-200 ° C. for about 0.5-30 seconds, and is oxidized by silver ions. Any leuco dye that forms a pigment can be used. Compounds that are pH sensitive and can be oxidized to a colored state are useful.

  In the present invention, a color image forming agent that increases its absorbance at 600 to 700 nm when oxidized is particularly used as a cyan color-forming leuco dye. JP-A-59-206831 (in particular, λmax is 600 to 600). Compounds within the range of 700 nm), compounds (1) to (18) described in paragraphs “0032” to “0037” of JP-A-5-204087, and general formulas 4 to 7 of JP-A-11-231460. (Specifically, compounds No. 1 to No. 79 described in paragraph “0105”).

  A cyan color-forming leuco dye particularly preferably used in the present invention is represented by the following general formula (CL).

In the formula, R ₈₁ and R ₈₂ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, alkenyl group, alkoxy group, —NHCO—R ₁₀ group (R ₁₀ is an alkyl group, aryl group, heterocyclic group) Or R ₈₁ and R ₈₂ are groups which are linked to each other to form an aliphatic hydrocarbon ring, an aromatic hydrocarbon ring or a heterocyclic ring. A ₈ represents a —NHCO— group, a —CONH— group or a —NHCONH— group, and R ₈₃ represents a substituted or unsubstituted alkyl group, aryl group or heterocyclic group. In addition, —A ₈ —R ₈₃ may be a hydrogen atom. W ₈ is a hydrogen atom, —CONH—R ₈₅ group, —CO—R ₈₅ group, or —CO—O—R ₈₅ group (R ₈₅ represents a substituted or unsubstituted alkyl group, aryl group, or heterocyclic group). R ₈₄ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, alkenyl group, alkoxy group, carbamoyl group, or nitrile group. R ₈₆ represents a —CONH—R ₈₇ group, a —CO—R ₈₇ group, or a —CO—O—R ₈₇ group (R ₈₇ represents a substituted or unsubstituted alkyl group, aryl group or heterocyclic group).
X ₈ represents a substituted or unsubstituted aryl group or heterocyclic group.

In the general formula (CL), examples of the halogen atom represented by R ₈₁ and R ₈₂ include a fluorine atom, a bromine atom, and a chlorine atom, and the alkyl group includes an alkyl group having up to 20 carbon atoms (for example, Methyl group, ethyl group, butyl group, dodecyl group, etc.). Examples of the alkenyl group include alkenyl groups having up to 20 carbon atoms (for example, vinyl group, allyl group, butenyl group, hexenyl group, hexadienyl group, ethenyl-2-ethyl group). A propenyl group, a 3-butenyl group, a 1-methyl-3-propenyl group, a 3-pentenyl group, a 1-methyl-3-butenyl group, and the like. As the alkoxy group, an alkoxy group having up to 20 carbon atoms (for example, methoxy) Group, ethoxy and the like). Examples of the alkyl group represented by R ₁₀ in the —NHCO—R ₁₀ group include alkyl groups having up to 20 carbon atoms (for example, a methyl group, an ethyl group, a butyl group, a dodecyl group, etc.), and an aryl group. Examples thereof include a group having 6 to 20 carbon atoms such as a phenyl group and a naphthyl group, and examples of the heterocyclic group include a thiophene group, a furan group, an imidazole group, a pyrazole group, and a pyrrole group. Alkyl group represented by R ₈₃ is preferably an alkyl group having up to 20 carbon atoms, such as methyl group, ethyl group, butyl group, dodecyl group and the like, the aryl group preferably having 6 to 20 carbon atoms Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the heterocyclic group include a thiophene group, a furan group, an imidazole group, a pyrazole group, and a pyrrole group. In the —CONH—R ₈₅ group, —CO—R ₈₅ group or —CO—O—R ₈₅ group represented by W ₈ , the alkyl group represented by R ₈₅ is preferably an alkyl group having up to 20 carbon atoms. Examples thereof include a methyl group, an ethyl group, a butyl group, and a dodecyl group. The aryl group is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group and a naphthyl group. Examples of the heterocyclic group include a thiophene group, a furan group, an imidazole group, a pyrazole group, and a pyrrole group.

Examples of the halogen atom represented by R ₈₄ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a chain or cyclic alkyl group such as a methyl group, a butyl group, and dodecyl. Group, cyclohexyl group and the like. Examples of the alkenyl group include alkenyl groups having up to 20 carbon atoms (for example, vinyl group, allyl group, butenyl group, hexenyl group, hexadienyl group, ethenyl-2-propenyl group, 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl, etc.), and alkoxy groups include, for example, methoxy group, butoxy group, tetradecyloxy group, etc., and carbamoyl Examples of the group include a diethylcarbamoyl group and a phenylcarbamoyl group.

Nitrile groups are also preferred. Among these, a hydrogen atom and an alkyl group are more preferable. R ₈₃ and R ₈₄ may be connected to each other to form a ring structure.

  The above groups can further have a single substituent or multiple substituents. Typical substituents include halogen atoms (eg, fluorine atom, chlorine atom, bromine atom), alkyl groups (eg, methyl group, ethyl group, propyl group, butyl group, dodecyl group), hydroxyl group, cyano group , Nitro group, alkoxy group (for example, methoxy group, ethoxy group, etc.), alkylsulfonamide group (for example, methylsulfonamide group, octylsulfonamide group, etc.), arylsulfonamide group (for example, phenylsulfonamide group, naphthylsulfone) Amide group etc.), alkylsulfamoyl group (eg butylsulfamoyl group etc.), arylsulfamoyl (eg phenylsulfamoyl group etc.), alkyloxycarbonyl group (eg methoxycarbonyl group etc.), aryl Oxycarbonyl group (for example, phenyloxycarbonyl group, etc.) , Amino sulfonamido group, an acylamino group, a carbamoyl group, a sulfonyl group, a sulfinyl group, a sulfoxy group, a sulfo group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, arylcarbonyl group, and an amino carbonyl group.

R ₁₀ or R ₈₅ is preferably a phenyl group, more preferably a phenyl group having a plurality of halogen atoms and cyano groups as substituents.

-CONH-R ₈₇ group represented by R _86, in -CO-R ₈₇ group, or -CO-O-R ₈₇ group, the alkyl group represented by R ₈₇ is preferably an alkyl group having up to 20 carbon atoms Yes, for example, a methyl group, an ethyl group, a butyl group, a dodecyl group, and the like. The aryl group is preferably an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, a thienyl group, and the like. Examples of the heterocyclic group include a thiophene group, a furan group, an imidazole group, a pyrazole group, and a pyrrole group.

As the substituent that the group represented by R ₈₇ can have, the same substituents as those described in the description of R _{81 to} R _{84 in} formula (CL) can be used.

Examples of the aryl group represented by X ₈ include aryl groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, and thienyl group. Examples of the heterocyclic group include thiophene group, furan group, and imidazole. Group, pyrazole group, pyrrole group and the like.

Examples of the substituent that the group represented by X ₈ can have include the same substituents as those described in the description of R _{81 to} R _{84 in} formula (CL). The group represented by X ₈ is preferably an aryl group or heterocyclic group having an alkylamino group (such as a diethylamino group) at the para position. These groups may include photographically useful groups.

  Specific examples of the cyan coloring leuco dye (CL) are shown below, but the cyan coloring leuco dye used in the present invention is not limited thereto.

  The addition amount of the cyan coloring leuco dye is usually 0.00001 to 0.05 mol / Ag1 mol, preferably 0.0005 to 0.02 mol / Ag1 mol, more preferably 0.001 to 0.01 mol. / Ag1 mol. The addition ratio of the cyan color-forming leuco dye to the total of the reducing agents is preferably 0.001 to 0.2, more preferably 0.005 to 0.1, in terms of molar ratio.

  In the present invention, the sum of the maximum densities at the maximum absorption wavelength of the dye image formed with the cyan leuco dye is preferably 0.01 or more and 0.50 or less, more preferably 0.02 or more and 0.30 or less, particularly preferably. Is preferably colored so as to have 0.03 or more and 0.10 or less.

  In the present invention, a subtle color tone can be adjusted by using a magenta chromogenic leuco dye or a yellow chromogenic leuco dye in addition to the cyan chromogenic leuco dye.

  As a method for adding the compounds represented by the general formulas (YA) and (YB) and the cyan chromophoric leuco dye, it can be contained in the coating solution by any method such as a solution form, an emulsified dispersion form, a solid fine particle dispersion form, You may make it contain in a photosensitive material.

  The compounds of the general formulas (YA) and (YB) and the cyan chromophoric leuco dye are preferably contained in an image forming layer containing an organic silver salt, but one is in the image forming layer and the other is in the image forming layer. You may make it contain in an adjacent non-image forming layer, and may make both contain in a non-image forming layer. When the image forming layer is composed of a plurality of layers, they may be contained in separate layers.

  Moreover, it is preferable to adjust each dye density | concentration appropriately in relation to the color tone by developing silver itself. In the present invention, it is preferable that the color tone is adjusted so that the image has a reflection optical density of 0.01 to 0.05 or a transmission optical density of 0.005 to 0.05, and an image in a preferable color tone range is obtained. .

〔binder〕
Binder suitable for the silver salt photothermographic dry imaging material of the present invention is transparent or translucent and generally colorless, and is a natural polymer synthetic resin, polymer and copolymer, and other media for forming a film, such as JP-A-2001-330918. Examples are those described in paragraph [0069] of the publication. Among these, preferred binders for the photosensitive layer of the silver salt photothermographic dry imaging material of the present invention are polyvinyl acetals, and a particularly preferred binder is polyvinyl butyral. Details will be described later. In addition, for non-photosensitive layers such as overcoat layers and undercoat layers, especially protective layers and backcoat layers, cellulose esters which are polymers having a higher softening temperature, particularly polymers such as triacetyl cellulose and cellulose acetate butyrate Is preferred. If necessary, the above binders can be used in combination of two or more. The binder (representing M is a hydrogen atom or an alkali metal _{salt,) -COOM, -SO 3 M,} -OSO 3 M, -P = O (OM) 2, -O-P = O (OM) 2,, At least one polar group selected from —N (R) ₂ , —N + (R) ₃ (R represents a hydrocarbon group), epoxy group, —SH, —CN, etc. is introduced by copolymerization or addition reaction. In particular, —SO ₃ M and —OSO ₃ M are preferable. The amount of such a polar group is 1 × 10 ⁻¹ to 1 × 10 ⁻⁸ mol / g, preferably 1 × 10 ⁻² to 1 × 10 ⁻⁶ mol / g.

Such a binder is used in an effective range to function as a binder. The effective range can be easily determined by one skilled in the art. For example, in the photosensitive layer, as an index in the case of holding at least the organic silver salt, the ratio of the binder to the organic silver salt is preferably 15: 1 to 1: 2, particularly in the range of 8: 1 to 1: 1. preferable. That is, it is preferable amount of the binder in the photosensitive layer is 1.5~6g / m ^2. More preferably, it is 1.7-5 g / m < ² >. If it is less than 1.5 g / m ² , the density of the unexposed area is significantly increased and may not be used.

  In the present invention, a photosensitive layer containing non-photosensitive aliphatic silver carboxylate grains, photosensitive silver halide grains, a silver ion reducing agent and a binder is developed at a temperature of 100 ° C. or higher. It is preferable that the heat transition temperature after performing is 46 degreeC or more and 200 degrees C or less.

  The heat transition temperature referred to in the present invention is a value indicated by the VICAT softening point or ring-and-ball method, and is a differential scanning calorimeter (DSC) such as EXSTAR 6000 (manufactured by Seiko Electronics), DSC220C (manufactured by Seiko Electronics Industry), An endothermic peak when a heat-developed photosensitive layer is isolated and measured using DSC-7 (manufactured by Perkin Elmer) or the like. In general, polymer compounds have a glass transition temperature, but in silver salt photothermographic dry imaging materials, a large endothermic peak appears below the glass transition temperature of the binder resin used in the photosensitive layer. To do. As a result of diligent investigation focusing on this thermal transition temperature, by setting the thermal transition temperature to 46 ° C. or higher and 200 ° C. or lower, not only the fastness of the formed coating film is increased, but also the sensitivity and the maximum density are increased. In addition, photographic performance such as image storability is greatly improved.

  The glass transition temperature Tg of the binder used in the present invention is preferably 70 ° C. or higher and 105 ° C. or lower. Tg can be obtained by measuring with a differential scanning calorimeter, and the intersection of the baseline and the endothermic peak slope is taken as the glass transition point.

  In the present invention, the glass transition temperature (Tg) is obtained by the method described in “Polymer Handbook” by Brandrup et al., Pages 139 to -179 (1966, Wiley and Sun, Inc.).

  Tg when the binder is a copolymer resin is obtained by the following formula.

Tg (copolymer) (° C.) = V ₁ Tg ₁ + v ₂ Tg ₂ +... + V _n Tg _{n
Wherein, v 1, v 2 ··· v} n represents the mass fraction of the monomer in the _{copolymer, Tg 1, Tg 2 ··· Tg} n from each monomer in the copolymer Tg (° C.) of the obtained single polymer is represented.

  The accuracy of Tg calculated according to the above equation is ± 5 ° C.

  Use of a binder having a Tg of 70 to 105 ° C. is preferable because a sufficient maximum density can be obtained in image formation.

  The binder according to the present invention has a Tg of 70 to 105 ° C., a number average molecular weight of 1,000 to 1,000,000, preferably 10,000 to 500,000, and a degree of polymerization of about 50 to 1,000. Is.

  Examples of the polymer or copolymer containing an ethylenically unsaturated monomer as a structural unit include those described in paragraph [0069] of JP-A No. 2001-330918.

  Among these, particularly preferred examples include methacrylic acid alkyl esters, methacrylic acid aryl esters, styrenes, and the like. Among such polymer compounds, a polymer compound having an acetal group is preferably used. Even a high molecular compound having an acetal group is more preferably a polyvinyl acetal having an acetoacetal structure, for example, U.S. Pat. Nos. 2,358,836, 3,003,879, and 2,828,204. And polyvinyl acetals shown in the specifications of British Patent 771,155.

  As the polymer compound having an acetal group, a compound represented by the following general formula (V) is particularly preferable.

In the formula, R ₁₁₁ represents an unsubstituted alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group, but is preferably a group other than an aryl group. R ₁₁₂ represents an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aryl group, a substituted aryl group, —COR ₁₁₃ or —CONHR ₁₁₃ . R ₁₁₃ has the same _meaning as R ₁₁₁ .

  The polymer compound represented by the general formula (V) can be synthesized by a general synthesis method described in “Vinyl Acetate Resin” edited by Ichiro Sakurada (Polymer Chemistry Press, 1962).

  These polymer compounds (polymers) may be used alone or in a blend of two or more. In the photosensitive layer according to the present invention, the above polymer is used as a main binder. The main binder here refers to “the state in which the polymer occupies 50% by mass or more of the total binder of the photosensitive layer”. Therefore, other polymers may be blended and used within a range of less than 50% by weight of the total binder.

  In the present invention, an organic gelling agent may be contained in the photosensitive layer. In addition, the organic gelling agent as used herein refers to a function of adding a yield value to the system by adding it to an organic liquid, such as polyhydric alcohols, and eliminating or reducing the fluidity of the system. The compound which has this.

  In the present invention, it is also a preferred embodiment that the photosensitive layer coating liquid contains a polymer latex dispersed in water. In this case, a polymer latex in which 50% by mass or more of the total binder in the coating solution for the photosensitive layer is dispersed in water is preferable.

  Moreover, when the photosensitive layer which concerns on this invention contains polymer latex, it is preferable that 50 mass% or more of all the binders in the said photosensitive layer is polymer latex, More preferably, it is 70 mass% or more.

  The “polymer latex” according to the present invention is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure, and the molecular chain itself is molecularly dispersed. Any of these may be used.

  The average particle diameter of the dispersed particles is preferably 1 to 50,000 nm, more preferably in the range of about 5 to 1,000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

  The polymer latex according to the present invention may be a so-called core / shell type latex in addition to a normal polymer latex having a uniform structure. In this case, it may be preferable to change the glass transition temperature between the core and the shell. The minimum film-forming temperature (MFT) of the polymer latex according to the present invention is preferably -30 to 90 ° C, more preferably about 0 to 70 ° C. Further, a film-forming auxiliary may be added to control the minimum film-forming temperature. The film-forming aid used in the present invention is an organic compound (usually an organic solvent) that is called a plasticizer and lowers the minimum film-forming temperature of the polymer latex. Published by Publishing Association (1970)) ”.

  Examples of the polymer species used for the polymer latex 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 usually about 5,000 to 1,000,000, preferably about 10,000 to 100,000 in terms of number average molecular weight. When the molecular weight is too small, the mechanical strength of the photosensitive layer is insufficient, and when the molecular weight is too large, the film forming property is poor, which is not preferable.

  The polymer latex preferably has an equilibrium water content of 0.01 to 2% by mass or less at 25 ° C. and 60% RH, and more preferably 0.01 to 1% by mass. For the definition and measurement method of the equilibrium moisture content, for example, “Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Polymer Society, Jinshokan)” can be referred to.

  Specific examples of the polymer latex include latexes described in paragraph No. [0173] of JP-A No. 2002-287299.

  These polymers may be used alone or as a blend of two or more as necessary. As a polymer seed | species of a polymer latex, what contains about 0.1-10 mass% of carboxylic acid components, such as an acrylate or a methacrylate component, is preferable.

  Furthermore, if necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose or the like may be added within a range of 50% by mass or less of the total binder. The addition amount of these hydrophilic polymers is preferably 30% by mass or less based on the total binder of the photosensitive layer.

  In the preparation of the coating solution for the photosensitive layer according to the present invention, any of the organic silver salt and the aqueous dispersed polymer latex may be added first or simultaneously. Preferably, the polymer latex is later.

  Furthermore, it is preferable that an organic silver salt and further a reducing agent are mixed before adding the polymer latex. In the present invention, after mixing the organic silver salt and the polymer latex, if the temperature to be aged is too low, the coating surface shape is impaired, and if it is too high, the fog rises. It is preferable that the following time is elapsed at 30 ° C. to 65 ° C. Furthermore, it is preferable to make it age at 35 to 60 degreeC, and it is especially preferable to age at 35 to 55 degreeC. In order to maintain the temperature in this way, the preparation tank of the coating solution may be kept warm.

  For coating of the coating solution for the photosensitive layer according to the present invention, it is preferable to use a coating solution that has passed from 30 minutes to 24 hours after mixing the organic silver salt and the aqueous-dispersed polymer latex, and more preferably after mixing. 60 minutes to 12 hours, particularly preferably 120 minutes to 10 hours.

  Here, “after mixing” means after the organic silver salt and the aqueous polymer latex are added and the additive material is uniformly dispersed.

  In the present invention, it is known that the use of a crosslinking agent with respect to the binder improves the film formation and reduces development unevenness. However, it suppresses fogging during storage and produces printed silver after development. There is also an inhibitory effect.

  As the crosslinking agent used in the present invention, various crosslinking agents conventionally used for photographic materials, for example, aldehyde-based, epoxy-based, ethyleneimine-based described in JP-A-50-96216, Vinyl sulfone type, sulfonic acid ester type, acryloyl type, carbodiimide type, and silane compound type cross-linking agents are used. Preferred are isocyanate type compounds, silane compounds, epoxy compounds, and acid anhydrides shown below.

  The isocyanate-based crosslinking agent includes isocyanates having at least two isocyanate groups and adducts thereof (adducts), and more specifically, aliphatic diisocyanates and aliphatic diisocyanates having a cyclic group. Benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and divalent or trivalent with these isocyanates Examples include adducts with polyalcohols.

  As specific examples, isocyanate compounds described on pages 10 to 12 of JP-A-56-5535 can be used.

  Incidentally, the adduct of isocyanate and polyalcohol has particularly high ability to improve interlayer adhesion and prevent layer peeling, image shift and bubble generation. Such isocyanates may be placed in any part of the photothermographic material. For example, in the support (especially when the support is paper, it can be included in the size composition). Photosensitivity of the support such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer. It can be added to any layer on the layer side, and can be added to one or more of these layers.

  In addition, as the thioisocyanate-based crosslinking agent that can be used in the present invention, compounds having a thioisocyanate structure corresponding to the above isocyanates are also useful.

  The amount of the crosslinking agent used in the present invention is usually in the range of 0.001 to 2 mol, preferably 0.005 to 0.5 mol, with respect to 1 mol of silver.

  The isocyanate compound and thioisocyanate compound that can be contained in the present invention are preferably compounds that function as the crosslinking agent.

  Examples of the silane compound that can be used as a crosslinking agent in the present invention include compounds represented by general formulas (1) to (3) disclosed in JP-A No. 2001-264930.

  The epoxy compound that can be used as a crosslinking agent in the present invention is not particularly limited as long as it has one or more epoxy groups, and the number of epoxy groups, molecular weight, and the like. The epoxy group is preferably contained in the molecule as a glycidyl group via an ether bond or an imino bond. Moreover, any of a monomer, an oligomer, a polymer, etc. may be sufficient as an epoxy compound, and the number of the epoxy groups which exist in a molecule | numerator is about 1-10 normally, Preferably it is 2-4. When the epoxy compound is a polymer, it may be either a homopolymer or a copolymer, and the number average molecular weight Mn thereof is particularly preferably in the range of about 2,000 to 20,000.

  The acid anhydride used in the present invention is a compound having at least one acid anhydride group represented by the following structural formula.

-CO-O-CO-
The acid anhydride used in the present invention is not particularly limited as long as it has one or more such acid anhydride groups, and the number, molecular weight, etc. of the acid anhydride groups.

Said epoxy compound and acid anhydride may use only 1 type, or may use 2 or more types together. The addition amount is not particularly limited, but is preferably in the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² , more preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol / m ² . It is.

  In the present invention, the epoxy compound or acid anhydride can be added to any layer on the photosensitive layer side of the support such as the photosensitive layer, the surface protective layer, the intermediate layer, the antihalation layer, and the undercoat layer. It can be added to one or more layers.

[Silver saving agent]
In the present invention, the effect of the present invention can be further enhanced by using a silver saving agent.

  The silver saving agent used in the present invention refers to a compound that can reduce the amount of silver necessary to obtain a certain silver image density. Various action mechanisms of the function of decreasing can be considered, but a compound having a function of improving the covering power of developed silver is preferable. Here, the covering power of developed silver refers to the optical density per unit amount of silver.

  Preferred examples of the silver saving agent include hydrazine derivative compounds, vinyl compounds, quaternary onium compounds and silane compounds.

  Specific examples of the hydrazine derivative include compounds H-1 to H-29 described in US Pat. No. 5,545,505, columns 11 to 20, US Pat. No. 5,464,738, columns 9 to 11. 1 to 12 described in JP-A-2001-27790, compounds H-1-1 to H-1-28 described in paragraph numbers [0042] to [0052], and H-2-1 to H-2- 9, H-3-1 to H-3-12, H-4-1 to H-4-21, H-5-1 to H-5-5.

  Specific examples of the vinyl compound include compounds CN-01 to CN-13 described in columns 13 to 14 of US Pat. No. 5,545,515, and column 10 of US Pat. No. 5,635,339. Compounds HET-01 to HET-02 described, compounds MA-01 to MA-07 described in columns 9-10 of US Pat. No. 5,654,130, US Pat. No. 5,705,324 Examples include compounds IS-01 to IS-04 described in columns 9 to 10 of the specification, and compounds 1-1 to 218-2 described in paragraph numbers [0043] to [0088] of JP-A No. 2001-125224.

  Specific examples of the quaternary onium compound include triphenyltetrazolium.

  Specific examples of the silane compound include alkoxysilane compounds having two or more primary or secondary amino groups as shown in compounds A1 to A33 described in paragraphs [0027] to [0029] of JP-A No. 2003-5324 or The salt is mentioned.

The amount of the silver saving agent added is in the range of 1 × 10 ⁻⁵ to 1 mol, preferably 1 × 10 ^{−4 to} 5 × 10 ⁻¹ mol, per mol of the organic silver salt.

[Anti-fogging and image stabilizer]
The antifogging and image stabilizer used in the silver salt photothermographic dry imaging material of the present invention will be described.

  As reducing agents, reducing agents having protons such as bisphenols and sulfonamidophenols are mainly used. Therefore, the reducing agent is not generated by generating active species capable of extracting these hydrogens. It is preferable that the compound which can be activated is contained. Preferably, the colorless photo-oxidizing substance is preferably a compound capable of generating free radicals as reactive active species during exposure.

  Accordingly, any compound having these functions may be used, but an organic free radical composed of a plurality of atoms is preferred. A compound having any structure may be used as long as it has such a function and does not cause any particular adverse effects on the silver salt photothermographic dry imaging material.

  In addition, as a compound that generates these free radicals, a carbocyclic or heterocyclic ring is used so that the generated free radicals are stable enough to be in contact with the reducing agent for a sufficient period of time to be inactivated. Those having an aromatic group of the formula are preferred.

  Representative examples of these compounds include biimidazolyl compounds and iodonium compounds.

The amount of the biimidazolyl compound or iodonium compound added is in the range of 0.001 to 0.1 mol / m ² , preferably 0.005 to 0.05 mol / m ² . The compound can be contained in any constituent layer in the light-sensitive material of the present invention, but is preferably contained in the vicinity of the reducing agent.

  Many compounds capable of releasing halogen atoms as active species are known as antifogging and image stabilizers.

  The amount of these compounds added is preferably within a range in which the increase in printout silver due to the formation of silver halide is not a problem, and is a maximum of 150% or less, more preferably 100% in terms of the ratio to the compound that does not generate active halogen radicals. % Or less is preferable. Specific examples of the compound that generates these active halogen atoms include compounds (III-1) to (III-23) described in paragraph numbers [0086] to [0087] of JP-A No. 2002-169249. Can be mentioned.

  Next, antifoggants other than those described above that are preferably used in the present invention will be described.

  Examples of the antifoggant preferably used in the present invention include compound examples a to j described in paragraph No. [0012] of JP-A-8-314059 and paragraph No. [0028] of JP-A-7-209797. Thiosulfonate esters A to K described in JP-A No. 55-140833, compound examples (1) to (44) described from p14 of JP-A No. 55-140833, compounds described in paragraph No. [0063] of JP-A No. 2001-13627 ( I-1) to (I-6), (C-1) to (C-3) described in “0066”, compound (III-1) described in paragraph No. [0027] of JP-A-2002-90937 As compounds of (III-108), vinyl sulfones and / or β-halo sulfones, compounds VS-1 to VS-7 and compound H described in paragraph [0013] of JP-A-6-208192 -1 to HS-5, sulfonylbenzotriazole compounds KS-1 to KS-8 described in JP 2000-330235 A, and substituted propene nitrile compounds described in JP 2000-515995 A PR-01 to PR-08 can be mentioned.

  The antifoggant is generally used in an amount of at least 0.001 mole per mole of silver. Usually, the range is 0.01 to 5 moles of the compound relative to the moles of silver, preferably 0.02 to 0.6 moles of the compound relative to the moles of silver.

  In addition to the above compound, the silver salt photothermographic dry imaging material of the present invention may contain a compound conventionally known as an antifoggant, but the reactive species similar to the above compound Even if it is a compound which can produce | generate, the compound from which an antifogging mechanism differs may be sufficient. For example, U.S. Pat. Nos. 3,589,903, 4,546,075, 4,452,885, JP-A-59-57234, U.S. Pat. No. 3,874,946. Examples thereof include compounds described in the specification, JP 4,756,999, JP-A-9-288328, and JP-A-9-90550. Further, as other antifoggants, compounds disclosed in US Pat. No. 5,028,523 and European Patent Nos. 600,587, 605,981 and 631,176 are exemplified. Can be mentioned.

  When the reducing agent used in the present invention has an aromatic hydroxyl group (—OH), particularly in the case of bisphenols, a non-reducing compound having a group capable of forming a hydrogen bond with these groups is used. It is preferable to use together.

  In the present invention, specific examples of particularly preferred hydrogen bonding compounds include compounds (II-1) to (II-) described in paragraphs [0061] to [0064] of JP-A-2002-90937, for example. 40).

  The silver salt photothermographic dry imaging material of the present invention has an average particle size of Le (μm) contained in the outermost surface on the side having the photosensitive layer and a matting agent contained in the outermost surface on the side having the backcoat layer. When the average particle size of Lb / Le is Lb (μm), Lb / Le is preferably 1.5 or more and 10 or less. By setting Lb / Le within this range, density unevenness during thermal development can be improved.

[Surface layer]
In the present invention, the surface layer of the silver salt photothermographic dry imaging material (when the photosensitive layer side or the non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support sandwiched) is also an object of the present invention. In addition, it is preferable to use organic or inorganic powder as a matting agent in order to control the surface roughness. As the powder used in the present invention, a powder having a Mohs hardness of 5 or more is preferably used. As the powder, a known inorganic powder or organic powder can be appropriately selected and used. Examples of the inorganic powder include titanium oxide, boron nitride, SnO ₂ , SiO ₂ , Cr ₂ O ₃ , α-Al ₂ O ₃ , α-Fe ₂ O ₃ , α-FeOOH, SiC, cerium oxide, corundum, artificial Examples thereof include diamond, garnet, garnet, mica, silica, silicon nitride, silicon carbide and the like. Examples of the organic powder include powders such as polymethyl methacrylate, polystyrene, and Teflon (registered trademark). Among these, inorganic powders such as SiO ₂ , titanium oxide, barium sulfate, α-Al ₂ O ₃ , α-Fe ₂ O ₃ , α-FeOOH, Cr ₂ O ₃ , mica, etc. are preferable. , SiO ₂ and α-Al ₂ O ₃ are preferable, and SiO ₂ is particularly preferable.

  In the present invention, the powder is preferably surface-treated with a Si compound or an Al compound. By using such surface-treated powder, the surface state of the uppermost layer can be improved. The content of Si or Al is preferably 0.1 to 10% by mass of Si and 0.1 to 10% by mass of Al, more preferably 0.1 to 10% by mass with respect to the powder. It is particularly preferable that 5% by mass, Al is 0.1-5% by mass, Si is 0.1-2% by mass, and Al is 0.1-2% by mass. The mass ratio of Si and Al is preferably Si <Al. The surface treatment can be performed by the method described in JP-A-2-83219. The average particle diameter of the powder in the present invention is the average diameter in the case of spherical powder, the average major axis length in the case of acicular powder, and the maximum diagonal length of the plate-like surface in the case of plate-like powder. Mean values can be easily obtained from measurement with an electron microscope.

  The organic or inorganic powder preferably has an average particle size of 0.5 to 10 μm, more preferably 1.0 to 8.0 μm.

  The average particle diameter of the organic or inorganic powder contained in the outermost layer on the photosensitive layer side is usually 0.5 to 8.0 μm, preferably 1.0 to 6.0 μm, more preferably 2.0 to 5.0 μm. It is. The addition amount is usually 1.0 to 20% by mass, preferably 2.0 to 15% by mass, and more preferably 3% with respect to the amount of binder used in the outermost layer (the curing agent includes the binder amount). 0.0 to 10% by mass. The average particle size of the organic or inorganic powder contained in the outermost layer opposite to the photosensitive layer side across the support is usually 2.0 to 15.0 μm, preferably 3.0 to 12.0 μm. More preferably, it is 4.0-10.0 micrometers. The addition amount is usually 0.2 to 10% by mass, preferably 0.4 to 7% by mass, and more preferably 0 to the amount of binder used in the outermost layer (the curing agent includes the binder amount). .6 to 5% by mass.

  The variation coefficient of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

  Here, the variation coefficient of the particle size distribution is a value represented by the following equation.

{(Standard deviation of particle size) / (Average value of particle size)} × 100
The method of adding the organic or inorganic powder may be a method in which the organic or inorganic powder is previously dispersed in the coating solution, or a method of spraying the organic or inorganic powder after the coating solution is applied and before the drying is completed. May be. Moreover, when adding several types of powder, you may use both methods together.

  Examples of the support material used in the silver salt photothermographic dry imaging material according to the present invention include various polymer materials, glass, wool cloth, cotton cloth, paper, metal (for example, aluminum), etc. A material that can be processed into a flexible sheet or roll is suitable for handling. Therefore, as a support in the silver salt photothermographic dry imaging material of the present invention, a plastic film (for example, cellulose acetate film, polyester film, polyethylene terephthalate film, polyethylene naphthalate film, polyamide film, polyimide film, cellulose triacetate film or polycarbonate film). Etc.) is preferred, and in the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferred. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

  In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layers in order to improve the chargeability. These may be contained in any layer, but are preferably contained in the backing layer or the surface protective layer on the photosensitive layer side, the undercoat layer, and the like. In the present invention, conductive compounds described in U.S. Pat. No. 5,244,773, columns 14 to 20 are preferably used.

In particular, in the present invention, the surface protective layer on the backing layer side preferably contains a conductive metal oxide. This proved that the effects of the present invention (particularly the transportability during heat development) can be further enhanced. Here, the conductive metal oxide is a crystalline metal oxide particle, and those containing an oxygen defect and those containing a small amount of different atoms that form a donor with respect to the metal oxide used are generally used. That is, it is particularly preferable because of its high conductivity, and the latter is particularly preferable because it does not give fog to the silver halide emulsion. Examples of metal oxides include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , V ₂ O _5, etc., or composite oxides thereof, especially ZnO, TiO ₂ and SnO ₂ are preferred. As an example of containing a heteroatom, addition Al, or In respect ZnO, Sb for SnO _2, Nb, P, the addition of such a halogen element, also Nb for TiO _2, Ta etc. Is effective. The amount of these different atoms added is preferably in the range of 0.01 to 30 mol%, but particularly preferably 0.1 to 10 mol%. Furthermore, a silicon compound may be added during the production of fine particles in order to improve fine particle dispersibility and transparency. The metal oxide fine particles used in the present invention have electrical conductivity, and the volume resistivity is 1 × 10 ⁷ Ω · cm or less, particularly 1 × 10 ⁵ Ω · cm or less. These oxides are described in JP-A Nos. 56-143431, 56-120519, and 58-62647. Furthermore, as described in Japanese Patent Publication No. 59-6235, a conductive material in which the above metal oxide is attached to other crystalline metal oxide particles or fibrous materials (for example, titanium oxide) may be used. Good.

The particle size that can be used is preferably 1 μm or less, but if it is 0.5 μm or less, the stability after dispersion is good and it is easy to use. In order to make the light scattering property as small as possible, it is very preferable to use conductive particles of 0.3 μm or less because a transparent photosensitive material can be formed. Further, when the conductive metal oxide is needle-like or fibrous, the length is preferably 30 μm or less and the diameter is preferably 1 μm or less, and particularly preferably the length is 10 μm or less and the diameter is 0.3 μm or less. The diameter ratio is 3 or more. As the SnO _2, are commercially available from Ishihara Sangyo Kaisha, it can be used SNS10M, SN-100P, SN- 100D, the FSS10M like.

  The silver salt photothermographic dry imaging material of the present invention has a photosensitive layer which is at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. For example, a protective layer is preferably provided on the photosensitive layer for the purpose of protecting the photosensitive layer, and the opposite surface of the support is prevented from sticking between the heat developing materials or in the heat developing material roll. In order to do so, a backcoat layer is provided. As a binder used in these protective layers and backcoat layers, a polymer having a glass transition point higher than that of the photosensitive layer and not easily scratched or deformed, such as polymers such as cellulose acetate and cellulose acetate butyrate, Chosen from the inside.

  For gradation adjustment or the like, two or more photosensitive layers may be provided on one side of the support or one or more layers on both sides of the support.

〔dye〕
In the silver salt photothermographic dry imaging material according to the present invention, a filter layer is formed on the same side as or opposite to the photosensitive layer in order to control the amount of light transmitted through the photosensitive layer or the wavelength distribution. It is preferable to contain a dye or a pigment in the functional layer.

  As the dye used in the present invention, known compounds that absorb light in various wavelength regions can be used according to the color sensitivity of the heat developing material.

  For example, when the silver salt photothermographic dry imaging material of the present invention is used as an image recording material by infrared light, a squarylium dye having a thiopyrylium nucleus as disclosed in JP-A-2001-83655 (in this publication, Use a thiopyrylium squarylium dye) and a squarylium dye having a pyrylium nucleus (referred to in this publication as a pyrylium squarylium dye), or a thiopyrylium croconium dye similar to a squarylium dye, or a pyrylium croconium dye. Is preferred.

  The compound having a squarylium nucleus is a compound having 1-cyclobutene-2-hydroxy-4-one in the molecular structure, and the compound having a croconium nucleus is 1-cyclopentene-2-hydroxy- in the molecular structure. It is a compound having 4,5-dione. Here, the hydroxy group may be dissociated. Hereinafter, in the present specification, these pigments are collectively referred to as squarylium dyes for convenience. As the dye, the compounds described in JP-A-8-201959 are also preferable.

[Application of constituent layers]
The silver salt photothermographic dry imaging material of the present invention is formed by preparing a coating solution in which the above-described constituent layers are dissolved or dispersed in a solvent, applying a plurality of these coating solutions simultaneously, and then performing a heat treatment. It is preferable. Here, "multiple simultaneous multi-layer coating" means that a coating solution for each constituent layer (for example, a photosensitive layer and a protective layer) is prepared, and each layer is repeatedly coated and dried when it is coated on a support. Rather, it means that each constituent layer can be formed in such a state that a multilayer coating and drying process can be performed simultaneously. That is, the upper layer is provided before the remaining amount of all the solvents in the lower layer reaches 70% by mass or less (more preferably 90% by mass or less).

  There are no particular restrictions on the method of applying multiple layers of each constituent layer simultaneously, for example, bar coater method, curtain coating method, dipping method, air knife method, slide hopper coating method, reverse roll coating method, gravure coating method, extrusion method. A known method such as a coating method can be used. Of these, a slide hopper coating method and an extrusion coating method are more preferable. These coating methods have been described on the side having the photosensitive layer, but the same applies to the case of coating with undercoating when providing the backcoat layer. Japanese Unexamined Patent Publication No. 2000-15173 has a detailed description on the simultaneous multilayer coating method in the heat development material.

In the present invention, the amount of coated silver is preferably selected in accordance with the purpose of the silver salt photothermographic dry imaging material, but for the purpose of medical images, 0.3 g / m ² or more, 2.0 g / m ² or less are preferred, 1.0 g / m ² or more, more preferably 1.7 g / m ² or less, 1.0 g / m ² or more, more preferably 1.6 g / m ² or less . Among the applied silver amount, those derived from silver halide preferably account for 2 to 18%, more preferably 5 to 15%, based on the total silver amount.

In the present invention, the coating density of silver halide grains having a particle diameter of 0.01 μm or more (equivalent particle diameter equivalent to a sphere) is preferably 1 × 10 ¹⁴ particles / m ² or more and 1 × 10 ¹⁸ particles / m ² or less. Furthermore, 1 × 10 ¹⁵ pieces / m ² or more and 1 × 10 ¹⁷ pieces / m ² or less are preferable.

Furthermore, the coating density of the non-photosensitive long-chain aliphatic carboxylate is 1 × 10 ⁻¹⁷ g or more, 1 × 10 1 per silver halide grain of 0.01 μm or more (equivalent particle diameter equivalent to sphere). ^-14 g or less is preferable, and 1 x 10 ^-16 g or more and 1 x 10 ^-15 g or less are more preferable.

  When coated under the conditions within the above range, it is preferable from the viewpoint of the optical maximum density of the silver image per fixed coated silver amount, that is, the silver coating amount (covering power) and the color tone of the silver image. Results are obtained.

In the present invention, the silver salt photothermographic dry imaging material preferably contains a solvent in the range of 5 to 1,000 mg / m ² during development. It is more preferable to adjust so that it may be 100-500 mg / m < ² >. As a result, a silver salt photothermographic dry imaging material with high sensitivity, low fog and high maximum density is obtained.

  Examples of the solvent include those described in paragraph [0030] of JP-A No. 2001-264930. However, it is not limited to these. These solvents can be used alone or in combination of several kinds.

  The content of the solvent in the silver salt photothermographic dry imaging material can be adjusted by changing conditions such as temperature conditions in the drying step after the coating step. The content of the solvent can be measured by gas chromatography under conditions suitable for detecting the contained solvent.

[Packaging]
When storing the silver salt photothermographic dry imaging material of the present invention, it is preferable to store and store it in a package in order to prevent changes in density and fogging over time. The porosity in the package is 0.01 to 10%, preferably 0.02 to 5%, and nitrogen sealing is performed to make the nitrogen partial pressure in the package 80% or more, preferably 90% or more. It is good.

[Exposure of silver salt photothermographic dry imaging materials]
In the silver salt photothermographic dry imaging material of the present invention, a laser beam is usually used for image recording. In the exposure of the silver salt photothermographic dry imaging material of the present invention, it is desirable to use a light source suitable for the color sensitivity imparted to the material. For example, if the material can be felt by infrared light, it can be applied to any light source as long as it is in the infrared light range. However, the laser power is high, or the silver salt photothermographic dry imaging material Infrared semiconductor lasers (780 nm, 820 nm) are more preferably used from the standpoint of being transparent.

  In the present invention, the exposure is preferably performed by laser scanning exposure, but various methods can be adopted as the exposure method. For example, as a first preferred method, there is a method using a laser scanning exposure machine in which the angle formed by the exposure surface of the photosensitive material and the scanning laser beam is not substantially perpendicular.

  Here, “substantially not perpendicular” means that the angle closest to the vertical during laser beam scanning is preferably 55 degrees or more and 88 degrees or less, more preferably 60 degrees or more and 86 degrees or less, and still more preferably. Means 65 degrees or more and 84 degrees or less, and most preferably 70 degrees or more and 82 degrees or less.

  The beam spot diameter on the photosensitive material exposure surface when the laser beam is scanned onto the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. This is preferable in that a smaller spot diameter can reduce the angle of deviation of the laser beam incident angle from the vertical. The lower limit of the beam spot diameter is 10 μm. By performing such laser scanning exposure, it is possible to reduce image quality deterioration related to reflected light such as generation of interference fringe-like unevenness.

  As a second method, the exposure in the present invention is preferably performed using a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi. Compared with a longitudinal single mode scanning laser beam, image quality degradation such as occurrence of interference fringe-like unevenness is reduced.

  In order to make it vertically multi-ply, a method such as using return light by combining or applying high-frequency superposition is preferable. Note that the vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

  Furthermore, as a third aspect, it is also preferable to form an image by scanning exposure using two or more laser beams.

  As such an image recording method using a plurality of laser beams, it is used in an image writing unit of a laser printer or a digital copying machine that writes an image line by line in one scan because of a demand for higher resolution and higher speed. This technique is known, for example, from Japanese Patent Laid-Open No. 60-166916. This is a method in which laser light emitted from a light source unit is deflected and scanned by a polygon mirror and imaged on a photoconductor via an fθ lens or the like. This is in principle the same laser scanning optics as a laser imager or the like. Device.

  The image formation of the laser beam on the photosensitive member in the image writing means of a laser printer or a digital copying machine is for one line from the image formation position of one laser beam for the purpose of writing an image by a plurality of lines in one scan. The next laser beam is imaged by shifting. Specifically, the two light beams are close to each other in the sub-scanning direction on the image plane at an interval of several tens of μm, and the printing density is 2 (400 dpi (dpi represents the number of dots per 2.54 cm)). The sub-scanning direction pitch of the beam is 63.5 μm and 42.3 μm at 600 dpi. Unlike the method of shifting the resolution in the sub-scanning direction as described above, in the present invention, it is preferable to form an image by condensing two or more lasers at the same place on the exposure surface while changing the incident angle. At this time, the exposure energy on the exposure surface when writing with one normal laser beam (wavelength λ [nm]) is E, and N laser beams used for exposure have the same wavelength (wavelength λ [nm]). ), In the case of the same exposure energy (En), the range of 0.9 × E ≦ En × N ≦ 1.1 × E is preferable. By doing so, energy is ensured on the exposure surface, but reflection of each laser beam to the photosensitive layer is reduced because the exposure energy of the laser is low, and thus occurrence of interference fringes is suppressed.

In the above description, the wavelengths of the plurality of laser beams are the same as λ, but those having different wavelengths may be used. In this case, it is preferable that (λ−30) <λ ₁ , λ ₂ ,... Λ _n ≦ (λ + 30) with respect to λ [nm].

In the image recording methods of the first, second, and third aspects described above, as lasers used for scanning exposure, generally well-known solid lasers such as ruby lasers, YAG lasers, glass lasers; Ne laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser, He—Cd laser, N ₂ laser, excimer laser and other gas lasers; InGaP laser, AlGaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP Semiconductor lasers such as ₂ lasers and GaSb lasers; chemical lasers, dye lasers, etc. can be selected and used in a timely manner, but among these, semiconductor lasers with a wavelength of 600 to 1200 nm due to maintenance and light source size problems It is preferable to use a laser beam. In the laser light used in a laser imager or a laser image setter, the beam spot diameter on the exposed surface of the material when scanned with the heat developing material is generally 5 to 75 μm as the minor axis diameter, and the major axis diameter. The laser beam scanning speed can be set to an optimum value for each silver salt photothermographic dry imaging material depending on the sensitivity and laser power at the laser oscillation wavelength inherent to the heat developing material.

[Heat development processing equipment]
The thermal development processing apparatus referred to in the present invention is composed of a film supply unit represented by a film tray, a laser image recording unit, a thermal development unit for supplying uniform and stable heat to the entire surface of the thermal development material, and a film supply unit. Through a laser recording, and a conveyance section from discharging the heat-developable photosensitive material image-formed by heat development out of the apparatus. A specific example of the heat development processing apparatus of this embodiment is shown in FIG.

  The thermal development apparatus 100 includes a feeding unit 110 that feeds the film F, which is a sheet-like thermal development material, one by one, an exposure unit 120 that exposes the fed film F, and a development that develops the exposed film F Section 130, cooling section 150 for stopping development and stacking section 160, supply roller pair 140 for supplying film F from the feeding section, supply roller pair 144 for feeding the film to the developing section, between the sections And a plurality of pairs of rollers such as conveying roller pairs 141, 142, 143, and 145 for smoothly transferring the film F. The developing unit as a heating means for developing the film F, a peeling claw for peeling the developed film F from the heat drum 1 having a plurality of opposing rollers 2 that can be heated while being held in close contact with the outer periphery, and sending it to the cooling unit 6 mag.

  In addition, as for the conveyance speed of silver salt photothermographic dry imaging material, 10-200 mm / sec is a preferable range.

  The development conditions of the silver salt photothermographic dry imaging material of the present invention will vary depending on the equipment, equipment or means used, but typically will heat the imagewise exposed photothermographic material at a suitable high temperature. By doing so, development is performed. The latent image obtained after the exposure is heated at a moderately high temperature (about 80 to 200 ° C., preferably about 100 to 200 ° C.) for a sufficient time (generally about 1 second to about 2 minutes). It is developed by doing.

  If the heating temperature is less than 80 ° C., sufficient image density cannot be obtained in a short time. If the heating temperature exceeds 200 ° C., the binder melts, and not only the image itself such as transfer to a roller but also to the transportability and developing machine. Also has an adverse effect. By heating, a silver image is generated by an oxidation-reduction reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This reaction process proceeds without any supply of treatment liquid such as water from the outside.

  The heating device, apparatus, or means may be a heating means typical as a heat generator using a hot plate, an iron, a hot roller, carbon, white titanium, or the like. More preferably, the heat-developable material provided with the protective layer is subjected to heat treatment by bringing the surface having the protective layer into contact with the heating means. It is preferable from the viewpoint, and it is preferable that the surface having the protective layer is conveyed while being in contact with the heat roller, and is heated and developed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. Unless otherwise specified, “%” in the examples represents “mass%”.

Example 1
<< Preparation of photosensitive silver halide emulsion >>
[Preparation of photosensitive silver halide emulsion 1]
(Solution A1)
Phenylcarbamoylated gelatin 88.3g
Compound A (* 1) (10% aqueous methanol solution) 10 ml
Potassium bromide 0.32g
Finished to 5429 ml with water (Solution B1)
0.67 mol / L silver nitrate aqueous solution 2635 ml
(Solution C1)
Potassium bromide 51.55g
Potassium iodide 1.47g
Finished to 660 ml with water (Solution D1)
Potassium bromide 154.9g
4.41 g of potassium iodide
K ₃ OsCl ₆ + K ₄ [Fe (CN) ₆ ] (dopant: each 2 × 10 ⁻⁵ mol / Ag equivalent) 50.0 ml
Finished to 1982 ml with water (Solution E1)
0.4 mol / L potassium bromide aqueous solution The following silver potential control amount (Solution F1)
Potassium hydroxide 0.71g
Finished to 20 ml with water (Solution G1)
56% acetic acid aqueous solution 18.0 ml
(Solution H1)
Anhydrous sodium carbonate 1.72 g
(* 1) Compound A: HO (CH ₂ CH ₂ O) _n (CH (CH ₃ ) CH ₂ O) ₁₇ (CH ₂ CH ₂ O) _m H (m + n = 5 to 7)
Using a mixing stirrer described in Japanese Patent Publication No. 58-58288, the solution A1 was adjusted to a ¼ amount of the solution B1 and a total amount of the solution C1 to 25 ° C. and pAg 8.09, while the mixture was mixed by the simultaneous mixing method. Addition took 45 minutes to nucleate. After 1 minute, the entire amount of solution F1 was added. During this time, the pAg was adjusted as appropriate using the solution E1. After the elapse of 6 minutes, 3/4 amount of the solution B1 and the whole amount of the solution D1 were added over 14 minutes and 15 seconds by the simultaneous mixing method while controlling to pAg8.09. After stirring for 5 minutes, the entire amount of the solution G1 was added to precipitate the silver halide emulsion. The supernatant was removed leaving 2000 ml of the sedimented portion, 10 L of water was added, and after stirring, the silver halide emulsion was sedimented again. The remaining portion of 1500 ml was left, the supernatant was removed, 10 L of water was further added, and after stirring, the silver halide emulsion was allowed to settle. After leaving 1500 ml of the sedimented portion and removing the supernatant, the solution H1 was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes. Finally, the pH was adjusted to 5.8, and water was added so that the amount was 1161 g per mole of silver to obtain a silver halide emulsion.

  The silver halide grains in the photosensitive silver halide emulsion 1 prepared as described above are monodispersed cubes having an average sphere equivalent diameter of 0.035 μm, a coefficient of variation of the sphere equivalent diameter of 12%, and a [100] plane ratio of 92%. It was silver iodobromide grains. It calculated | required from the average of 1000 particle | grains using the electron microscope. The [100] face ratio of the particles was determined using the Kubelka-Munk method.

<< Preparation of powdered organic silver salt containing silver halide grains >>
[Preparation of silver halide grain-containing powdered organic silver salt A-1]
Organic silver salt particles were prepared using unpurified behenic acid (commercially available reagent). When this behenic acid was analyzed by the analysis method described later, the behenic acid content was 80% by mass. Since the remainder contained arachidic acid and stearic acid, each organic acid reagent was adjusted to 132.1 g behenic acid, 67.7 g arachidic acid, and 43.6 g stearic acid using the arachidic acid and stearic acid reagents. It mixed, thrown into 4720 ml pure water, and melt | dissolved at 80 degreeC. Next, 540.2 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added, and 6.9 ml of concentrated nitric acid was added, followed by cooling to 55 ° C. to obtain a mixed fatty acid sodium solution. Add 45.3 g of the photosensitive silver halide emulsion 1 and 450 ml of pure water while keeping the temperature of the mixed fatty acid sodium solution at 55 ° C. with the light blocked (hereinafter, the light blocked state). And stirred for 5 minutes. Next, 702.6 ml of 1 mol / L silver nitrate aqueous solution was added over 2 minutes and stirred for 10 minutes to obtain organic silver salt particle dispersion A-1 containing silver halide particles. Thereafter, the obtained silver halide particle-containing organic silver salt particle dispersion A-1 is transferred to a water-washing vessel, deionized water is added thereto, and the mixture is stirred and allowed to stand to disperse the organic silver salt particles containing silver halide particles. The product A-1 was floated and separated, and the lower water-soluble salts were removed. Thereafter, washing with deionized water and drainage were repeated until the electrical conductivity of the drainage reached 2 μS / cm, and centrifugal dehydration was performed to obtain organic silver salt particles A-1 containing cake-like silver halide grains. Using a fluidized bed dryer (midget dryer MDF-64, manufactured by Dalton Co., Ltd.), the organic silver salt particles A-1 containing cake-like silver halide particles are operated in a nitrogen gas atmosphere and at the dryer hot air temperature. Depending on the conditions, it was dried until the water content became 0.1% to obtain a silver halide grain-containing powdered organic silver salt A-1. An infrared moisture meter was used to measure the moisture content of the powdered organic silver salt A-1 containing silver halide grains. As a result of quantifying the amount of behenic acid in the powdered organic silver salt A-1 containing silver halide grains by the following analytical method, the silver behenate contained in the powdered organic silver salt grains A-1 containing silver halide particles The ratio was 54% by mass. As a result of analyzing the mixed organic acid, the heavy metal content was 5 ppm and the iodine value was 1.5.

<Organic silver analysis method>
The silver behenate content was determined as follows. About 10 mg of organic silver salt is accurately weighed and placed in a 200 ml eggplant type Kolben. Add 15 ml of methanol and 3 ml of 4 mol / L hydrochloric acid and ultrasonically disperse for 1 minute. Add Teflon (registered trademark) zeolite and reflux for 60 minutes. After cooling, 5 ml of methanol is added from the top of the cooled product, and the material adhering to the cooling pipe is washed into eggplant type Kolben (twice). The obtained reaction solution is extracted with ethyl acetate (100 ml of ethyl acetate and 70 ml of water are added for liquid separation and twice). Vacuum dry for 30 minutes. Place 1 ml of benzanthrone solution (internal standard) in a 10 ml volumetric flask. Dissolve the sample in toluene and place in a volumetric flask. This is measured by GC, mol% from the peak area of each organic acid is determined, and the composition of all organic acids can be known by determining mass%.

  Subsequently, free organic acids that are not organic silver salts are quantified. About 20 mg of an organic silver salt sample is accurately weighed, and 10 ml of methanol is added and ultrasonically dispersed for 1 minute. When it is filtered and the filtrate is dried, free organic acid is extracted. Thereafter, the free organic acid composition and the ratio to the total organic acid can be known by measuring with GC in the same manner as in the case of the total organic acid. The total organic acid minus the free organic acid was defined as the composition of the organic acid present as an organic silver salt.

[Preparation of powdered organic silver salts A-2 to A-10 containing silver halide grains]
In the preparation of the powdered organic silver salt A-1 containing silver halide grains, the ratios of silver behenate (Be: silver behenate ratio, Ar: silver arachidate ratio, St: silver stearate ratio) shown in Table 1 are obtained. Thus, powder organic silver salt A-2-A-10 was obtained by the method similar to powder organic silver salt A-1 except having mixed each organic acid reagent.

[Preparation of silver halide grains-containing powdered organic silver salts B-1 to B-3]
In the preparation of the powdered organic silver salt A-1 containing the silver halide grains, the ratios of silver behenate (Be: silver behenate ratio, Ar: silver arachidate ratio, St: silver stearate ratio) shown in Table 1 are obtained. The mixed fatty acid potassium solution obtained by mixing each organic acid reagent as described above and adding a potassium hydroxide aqueous solution instead of a 1.5 mol / L sodium hydroxide aqueous solution was kept at a temperature of 55 ° C. Powdered organic silver salts B-1 to B-3 were obtained in the same manner as the powdered organic silver salt A-1, except that 347 ml of propanol was added.

<< Preparation of photosensitive emulsion dispersion A-1 >>
14.57 g of SO ₃ K group-containing polyvinyl butyral (Tg 75 ° C., containing SO ₃ K group of 0.2 mmol / g) is dissolved in 1457 g of methyl ethyl ketone, and dissolver DISPERMAT CA-40M type manufactured by VMA-GETZMANN While stirring at 500, 500 g of the above-mentioned powdered organic silver salt A-1 containing silver halide grains was gradually added and mixed thoroughly to prepare a preliminary dispersion A-1.

  Media type in which the preliminary dispersion A-1 is filled with 80% of the internal volume of 0.5 mm diameter zirconia beads (Traceram manufactured by Toray Industries, Inc.) using a pump so that the residence time in the mill is 1.5 minutes. This was supplied to a disperser DISPERMAT SL-C12EX type (manufactured by VMA-GETZMANN) and dispersed at a mill peripheral speed of 9 m / sec to prepare photosensitive emulsion dispersion A-1.

<< Preparation of photosensitive emulsion dispersions A-2 to A-10, B-1 to B-3 >>
In the preparation of the photosensitive emulsion dispersion A-1, in place of the silver halide particle-containing powder organic silver salt A-1, silver halide particle-containing powder organic silver salts A-2 to A-10, B- Photosensitive emulsion dispersions A-2 to A-10 and B-1 to B-3 were prepared in the same manner except that 1 to B-3 were used.

<Production of support>
One side of a 175 μm thick polyethylene terephthalate film colored blue at a concentration of 0.155 was subjected to a corona discharge treatment of 0.5 kV · A · min / m ² , and then the following undercoat coating solution A was applied thereon. The undercoat layer a was applied so that the dry film thickness was 0.2 μm. Further, the other surface was similarly subjected to a corona discharge treatment of 0.5 kV · A · min / m ² , and then the undercoat layer b was formed thereon using the following undercoat coating solution B to form a dry film The coating was applied so that the thickness was 0.1 μm. Thereafter, heat treatment was performed at 130 ° C. for 15 minutes in a heat treatment type oven having a film transport device composed of a plurality of roll groups.

(Undercoating liquid A)
270 g of copolymer latex liquid (solid content 30%) of butyl acrylate / t-butyl acrylate / styrene / 2-hydroxyethyl acrylate (30/20/25/25%), 0 of surfactant (UL-1) .6 g and 0.5 g of methylcellulose were mixed. Further, 1.3 g of silica particles (Syloid 350: manufactured by Fuji Silysia) was added to 100 g of water, and dispersion treatment was performed for 30 minutes with an ultrasonic disperser (manufactured by ALEX Corporation: Ultrasonic Generator, frequency 25 kHz, 600 W). The resulting dispersion was added and finally made up to 1000 ml with water.

(Undercoating liquid B)
37.5 g of the following colloidal tin oxide dispersion, a copolymer latex liquid (solid content 30%) of butyl acrylate / t-butyl acrylate / styrene / 2-hydroxyethyl acrylate (20/30/25/25%) 3.7 g, 14.8 g of a copolymer latex liquid (solid content 30%) of butyl acrylate / styrene / glycidyl methacrylate (40/20/40%) and 0.1 g of a surfactant (UL-1) The mixture was mixed and finished to 1000 ml with water.

<Preparation of colloidal tin oxide dispersion>
A homogeneous solution was prepared by dissolving 65 g of stannic chloride hydrate in 2000 ml of a water / ethanol mixed solution. Subsequently, this was boiled and the coprecipitate was obtained. The produced precipitate was taken out by decantation and washed several times with distilled water. Silver nitrate is dropped into the distilled water from which the precipitate has been washed, and after confirming that there is no reaction of chlorine ions, distilled water is added to the washed precipitate to make a total volume of 2000 ml. Further, 40 ml of 30% aqueous ammonia was added, the aqueous solution was heated, and concentrated to a volume of 470 ml to prepare a colloidal tin oxide dispersion.

<< Preparation of Sample 101 >>
Sample 101, which is a silver salt photothermographic dry imaging material, was prepared according to the following procedure.

[Back side application]
While stirring 830 g of methyl ethyl ketone, 84.2 g of cellulose acetate butyrate (manufactured by Eastman Chemical: CAB381-20) and 4.5 g of polyester resin (manufactured by Boston: VitelPE2200B) were added and dissolved. Next, 0.30 g of infrared dye 1, 4.5 g of fluorine-based activator-1 and 1.5 g of fluorine-based activator (Gemco: Ftop EF-105) are added to the dissolved liquid, Stir well until dissolved. Finally, 75 g of silica particles (manufactured by Fuji Silysia: Silicia 450) dispersed in methyl ethyl ketone at a concentration of 1% with a dissolver type homogenizer were added and stirred to prepare a back surface coating solution.

Fluorine-based activator-1: C ₉ F ₁₇ O (CH ₂ CH ₂ O) ₂₂ C ₉ F ₁₇
Next, the prepared back surface coating solution was applied at a coating speed of 35 m / min on the surface coated with the undercoat layer b of the support using an extrusion coater so that the dry film thickness was 3.5 μm. Drying was performed. It was dried for 5 minutes using a drying air having a drying temperature of 100 ° C. and a dew point temperature of 10 ° C.

[Coating on the photosensitive layer side]
(Preparation of each additive solution)
<Preparation of stabilizer solution>
A stabilizer liquid was prepared by dissolving 1.0 g of Stabilizer-1 and 0.31 g of potassium acetate in 4.97 g of methanol.

<Preparation of infrared sensitizing dye liquid A>
19.2 mg of infrared sensitizing dye-1, 1.488 g of 2-chloro-benzoic acid, 2.7779 g of stabilizer-2 and 365 mg of 5-methyl-2-mercaptobenzimidazole were added to 31.3 ml of methyl ethyl ketone. In the dark, an infrared sensitizing dye solution A was prepared.

<Preparation of additive solution a>
As a developer, 27.98 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (this is referred to as reducing agent A), a yellow coloring leuco dye (YA) -1), 0.159 g, 1.54 g, 0.159 g of cyan chromogenic leuco dye CA-12, 1.54 g of 4-methylphthalic acid, 0.48 g of infrared dye 1 are dissolved in 110 g of methyl ethyl ketone. The additive solution a was obtained.

<Preparation of additive liquid b>
3.56 g of antifoggant-2, 3.43 g of phthalazine were dissolved in 40.9 g of methyl ethyl ketone to obtain additive solution b.

(Preparation of photosensitive layer coating liquid A-1)
Under an inert gas atmosphere (nitrogen 97%), 50 g of the photosensitive emulsion dispersion A-1 and 15.11 g of methyl ethyl ketone were kept at 21 ° C. with stirring to prevent fogging 1 (10% methanol solution). 390 μl was added and stirred for 1 hour. Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 20 minutes. Subsequently, 167 μl of a stabilizer solution was added and stirred for 10 minutes, and then 1.32 g of the infrared sensitizing dye solution A was added and stirred for 1 hour. Thereafter, the temperature was lowered to 13 ° C. and further stirred for 30 minutes. While keeping the temperature at 13 ° C., SO ₃ K group-containing polyvinyl butyral (Tg 75 ° C., containing 0.2 mmol / g of SO ₃ K groups) as a binder resin, that is, (the binder resin used in the preliminary dispersion A-1) After adding 13.31 g and stirring for 30 minutes, 1.084 g of tetrachlorophthalic acid (9.4 mass% methyl ethyl ketone solution) was added and stirred for 15 minutes. While further stirring, 12.43 g of additive solution a, 1.6 ml of Desmodur N3300 (Mobey aliphatic isocyanate 10% methyl ethyl ketone solution), and 4.27 g of additive solution b were sequentially added and stirred. An aqueous layer coating solution A-1 was obtained.

(Preparation of surface protective layer coating solution)
While stirring 865 g of methyl ethyl ketone, 96 g of cellulose acetate butyrate (Eastman Chemical: CAB171-15), 4.5 g of polymethylmethacrylic acid (Rohm & Haas: Paraloid A-21), 1 of benzotriazole 0.0 g and 0.3 g of a fluorine-based activator (Gemco: F-top EF-105) were added and dissolved. Next, 30 g of the following matting agent dispersion was added and stirred to prepare a surface protective layer coating solution.

<Preparation of matting agent dispersion>
Dissolve 7.5 g of cellulose acetate butyrate (Eastman Chemical: CAB171-15) in 42.5 g of MEK, add 5 g of silica particles (Fuji Silysia: Silysia 320), and use a dissolver type homogenizer. Dispersion was performed at 8000 rpm for 30 minutes to prepare a matting agent dispersion.

(Application)
The photosensitive layer coating solution A-1 and the surface protective layer coating solution prepared above were simultaneously applied by multilayer coating at a coating speed of 40 m / min using a known extrusion coater. The coating was prepared so that the silver coating amount of the photosensitive layer was the amount described in Table 1. Also. The surface protective layer was formed to have a dry film thickness of 2.5 μm. Then, it dried for 10 minutes using the drying air with a drying temperature of 75 degreeC, and dew point temperature of 10 degreeC, and produced the sample 101. FIG.

<< Production of Samples 102 to 122 >>
In preparation of the said sample 101, except having changed the fluorine-type activator (The gemco company make: Ftop EF-105) used for preparation of a back surface coating liquid and / or a surface protective layer coating liquid as shown in Table 2. Similarly, samples 102 to 122 were produced.

<Evaluation of silver salt photothermographic dry imaging materials>
Various evaluations were performed on the manufactured samples 101 to 122 according to the following methods.
[Evaluation of density unevenness]
From the photosensitive layer coating surface side of each of the above prepared samples, the density after thermal development is about 2.0 by an exposure machine using a semiconductor laser having a wavelength of 800 to 820 nm as a longitudinal multimode as an exposure source. Thus, the entire surface was uniformly exposed by laser scanning. Thereafter, development (123 ° C., 14 seconds) was performed using the automatic developing machine having the heat drum and the cooling zone shown in FIG. 1 so that the protective layer of the sample and the drum surface were in contact with each other.

  The obtained sample was visually evaluated for density unevenness with a Schaukasten. The evaluation criteria are as follows, and the results are shown in Table 1.

5: Image density unevenness is hardly recognized 4: Slightly weak image density unevenness is recognized, but is in an acceptable range 3: Weak image density unevenness is recognized, and there is a practical concern 2: Slightly high image density Unevenness is observed and the quality is a problem in practical use 1: Strong image density unevenness is recognized and the quality is clearly a problem in practical use [exposure and development processing]
Exposure by laser scanning from the photosensitive layer-coated surface side of each of the above prepared samples by an exposure machine using an exposure source with a semiconductor laser having a longitudinal multimode wavelength of 800 to 820 nm by high frequency superposition through an optical wedge. Was given. At this time, the angle between the exposure surface of the sample and the exposure laser beam was set to 75 ° to form an image. In this case, an image with less unevenness and unexpectedly good sharpness or the like was obtained compared to the case where the angle was 90 °.

  Thereafter, development was performed using the automatic developing machine having the heat drum and the cooling zone shown in FIG. 1 so that the protective layer of the sample and the drum surface were in contact with each other. At that time, exposure and development were performed in a room adjusted to 23 ° C. and 50% RH.

(Measurement of fog density and maximum density)
The density of the obtained silver image composed of wedge gradations was measured with a densitometer, and a characteristic curve consisting of the logarithm (Log E) of the silver image density (D) on the vertical axis and the exposure amount (E) on the horizontal axis was created. .

  In this characteristic curve, the minimum density (fogging density) and the maximum density were determined.

<Evaluation of image preservation>
A sample that had been heat-developed by the same method as in the above sensitivity measurement was left in an environment of 25 ° C. and 45 ° C. for 3 days, then the change in maximum density was measured, and the rate of change in image density was measured as follows. Was a measure of image preservation.

Image density change rate =
Maximum concentration of sample stored at 45 ° C / Maximum concentration of sample stored at 25 ° C x 100 (%)
<Evaluation of storage stability over time>
After the obtained sample was stored for 10 days under the following two conditions, exposure and development were performed in the same manner as the sensitivity measurement, respectively, and the sensitivity of the obtained image was evaluated. The rate of change in sensitivity under condition B was determined from the following and used as a measure of storage stability over time.

Condition A: 25 ° C., 55% RH
Condition B: 40 ° C., 80% RH
Sensitivity change rate = sensitivity in condition B / sensitivity in condition A × 100 (%)

  As is clear from the results in Table 1, the silver salt photothermographic dry imaging material of the present invention is superior in storage stability and low density unevenness compared to the comparison, while being low fog and high density, It turns out that it is excellent in equipment transportability.

It is a section lineblock diagram showing an example of a heat development processing device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat drum 2 Opposing roller 6 Separation claw 100 Heat developing device 110 Feeding part 120 Exposure part 130 Developing part 140, 144 Supply roller pair 141, 142, 143 Conveying roller pair 150 Cooling part 151 Cooling roller pair 152 Cooling fan 160 Accumulating part F film

Claims (6)

On the support, non-photosensitive aliphatic carboxylic acid silver salt particles, a photosensitive silver halide emulsion containing photosensitive silver halide grains, a photosensitive layer and a constituent layer containing a silver ion reducing agent and a binder are provided. In the silver salt photothermographic dry imaging material, 80 mol% or more and 100 mol% or less of the non-photosensitive aliphatic carboxylate silver salt particles are composed of silver behenate, and at least one of the constituent layers has the following general formula ( 1. A silver salt photothermographic dry imaging material comprising the fluorine-based surfactant represented by 1).
General formula (1)
_{Rf- (O-Rf ') n} -L-X m
[Wherein, Rf represents an alkyl group, aryl group or alkenyl group containing at least one fluorine atom, Rf ′ represents an alkylene group containing at least one fluorine atom, and L represents a simple bond or linking group. X represents a hydroxy group, an anionic group or a cationic group. n represents the integer of 1-10, respectively, and m represents the integer of 1-3. ] On the support, non-photosensitive aliphatic carboxylic acid silver salt particles, a photosensitive silver halide emulsion containing photosensitive silver halide grains, a photosensitive layer and a constituent layer containing a silver ion reducing agent and a binder are provided. In the silver salt photothermographic dry imaging material, 80 mol% or more of the non-photosensitive aliphatic carboxylate silver salt particles are composed of silver behenate, and at least one of the constituent layers is represented by the following general formula (2). A silver salt photothermographic dry imaging material characterized by containing a fluorinated surfactant.
General formula (2)
_{[(Rf 3 O) n2 - (} PFC) -CO-Y 2 ] _{k -L 2 - (X 2)} m2
[In the formula, Rf ₃ represents a perfluoroalkyl group having 1 to 4 carbon atoms, (PFC) represents a perfluorocycloalkylene group, Y ₂ represents a linking group containing an oxygen atom or a nitrogen atom, L ₂ represents a simple bond or linking group, X ₂ represents a water-solubilizing polar group containing an anionic group, a cationic group, a nonionic group or an amphoteric group, n2 represents an integer of 1 to 5, Represents an integer of 1 to 3, and m2 represents an integer of 1 to 5. ] The silver salt photothermographic dry imaging material according to claim 1 or 2, wherein the total silver amount per 1 m ^{2 of the} photosensitive layer is 1.0 to 1.6 g. The silver salt photothermographic dry imaging material according to any one of claims 1 to 3, wherein an alkaline solution of potassium hydroxide is used when forming the non-photosensitive aliphatic carboxylate silver salt particles. An image recording method for a silver salt photothermographic dry imaging material, wherein the exposure to the silver salt photothermographic dry imaging material according to any one of claims 1 to 4 is a laser beam having a longitudinal multi. A silver salt photothermographic material, wherein the silver salt photothermographic dry imaging material image-recorded by the silver salt photothermographic dry imaging material image recording method according to claim 5 is heated and developed at a temperature of 80 ° C to 200 ° C. Image forming method of photographic dry imaging material.

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