Heat-developable photosensitive material and heat-developing method using the same

1 . A heat-developable photosensitive material comprising at least a photosensitive silver halide, a nonphotonsensitive organic silver salt, a reducing agent, a developing accelerator, a color adjusting agent and a binder on a support, wherein

said photosensitive material has an average contrast of 2.5 or more and 6 or less at a density between 1.5 and 3.0;

said photosensitive silver halide includes silver iodide at 5 mol % to 100 mol %; and

the average particle size of said photosensitive silver halide is 5 nm to 80 nm;

the developing accelerator is a compound represented by the following formula (I):

Q 1 -NHNH—R 1   Formula (I)

wherein, in the formula (I), Q 1 represents a five- to seven-membered unsaturated ring connected to NHNH—R 1 through a carbon atom, R 1 represents a group selected from a carbamoyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group and a sulfamoyl group; and

the reducing agent is represented by the following formula (VII):

wherein each of R 71 and R 71′ independently represents an alkyl group having 1 to 20 carbon-atoms, each of R 72 and R 72′ independently represents a hydrogen atom or a substituent with which a benzene ring may be substituted, each of X 71 and X 71′ independently represent a hydrogen atom or a substituent with which a benzene ring may be substituted, L represents one of —S— and —CHR 73 — and R 73 represents one of a hydrogen atom and an alkyl group having 1 to 20 carbon atoms.

2 . The heat-developable photosensitive material according to claim 1 , wherein said photosensitive silver halide includes the silver iodide at 40 mol % to 100 mol %.

3 . The heat-developable photosensitive material according to claim 1 , wherein the nonphotonsensitive organic silver salt is a fatty acid salt containing 50 mol % or more of silver behenate.

4 . A heat developing method for a heat-developable photosensitive material comprising steps of:

preparing a heat-developable photosensitive material, the heat-developable photosensitive material comprising at least a photosensitive silver halide, a nonphotonsensitive organic silver salt, a reducing agent, a developing accelerator, a color adjusting agent and a binder on a support, wherein

the photosensitive material has an average contrast of 2.5 or more and 6 or less at a density between 1.5 and 3.0;

with the photosensitive silver halide including silver iodide at 5 mol % to 100 mol % and the average particle size of said photosensitive silver halide being 5 nm to 80 nm;

image exposing the heat-developable photosensitive material; and

heat-developing the heat-developable photosensitive material at a maximum temperature of between 100° C. and 120° C.;

wherein the developing accelerator is a compound represented by the following formula (I):

Q 1 -NHNH—R 1   Formula (I)

wherein, in the formula (I), Q 1 represents a five- to seven-membered unsaturated ring connected to NHNH—R 1 through a carbon atom, R 1 represents a group selected from a carbamoyl group, an acyl group, an alkoxycarbonyl group, a sulfonyl group and a sulfamoyl group; and

said reducing agent is represented by the following formula (VII):

wherein each of R 71 and R 71′ independently represents an alkyl group having 1 to 20 carbon atoms, each of R 72 and R 72′ independently represents a hydrogen atom or a substituent with which a benzene ring may be substituted, each of X 71 and X 71′ independently represent a hydrogen atom or a substituent with which a benzene ring may be substituted, L represents one of —S— and —CHR 73 — and R 73 represents one of a hydrogen atom and an alkyl group having 1 to 20 carbon atoms.

5 . The heat developing method according to claim 4 , wherein the heat-developable photosensitive material is heat-developed at a maximum temperature of 105° C. to 115° C.

6 . The heat-developable photosensitive material according to claim 1 wherein the developing accelerator raises sensitivity at a density of 1.0 by 0.05 or more when 5 mol % of the reducing agent is substituted by the compound represented by formula (I).

7 . The heat developing method according to claim 4 , wherein the developing accelerator raises sensitivity at a density of 1.0 by 0.05 or more when 5 mol % of the reducing agent is substituted by the compound represented by formula (I).

8 . A heat-developable photosensitive material comprising at least a photosensitive silver halide, a nonphotonsensitive organic silver salt, a reducing agent, a developing accelerator, a color adjusting agent and a binder on a support, wherein

said photosensitive material does not contain a super-high tone agent;

said photosensitive material has an average contrast of 2.5 or more and 6 or less at a density between 1.5 and 3.0;

said photosensitive silver halide includes silver iodide at 5 mol % to 100 mol %; and

the average particle size of said photosensitive silver halide is 5 nm to 80 nm;

the developing accelerator is a compound represented by the following formula (II):

wherein, in the formula (II), X 2 represents a hydrogen atom or a substituent, R 21 represents a hydrogen atom or substituent, and p denotes an integer from 0 to 4;

and

the reducing agent is represented by the following formula (VII):

wherein each of R 71 and R 71′ independently represents an alkyl group having 1 to 20 carbon atoms, each of R 72 and R 72′ independently represents a hydrogen atom or a substituent with which a benzene ring may be substituted, each of X 71 and X 71′ independently represent a hydrogen atom or a substituent with which a benzene ring may be substituted, L represents one of —S— and —CHR 73 — and R 73 represents one of a hydrogen atom and an alkyl group having 1 to 20 carbon atoms.

9 . The heat-developable photosensitive material according to claim 8 , wherein said photosensitive silver halide includes the silver iodide at 40 mol % to 100 mol %.

10 . The heat-developable photosensitive material according to claim 8 , wherein the nonphotosensitive organic silver salt is a fatty acid salt containing 50 mol % or more of silver behenate.

11 . The heat-developable photosensitive material according to claim 8 , wherein the developing accelerator raises sensitivity at a density of 1.0 by 0.05 or more when 5 mol % of the reducing agent is substituted by the compound represented by formula (II).

12 . A heat developing method for a heat-developable photosensitive material comprising steps of:

preparing a heat-developable photosensitive material, the heat-developable photosensitive material comprising at least a photosensitive silver halide, a nonphotonsensitive organic silver salt, a reducing agent, a developing accelerator, a color adjusting agent and a binder on a support, wherein

the photosensitive material has an average contrast of 2.5 or more and 6 or less at a density between 1.5 and 3.0;

with the photosensitive silver halide including silver iodide at 5 mol % to 100 mol % and the average particle size of said photosensitive silver halide being 5 nm to 80 nm;

image exposing the heat-developable photosensitive material; and

heat-developing the heat-developable photosensitive material at a maximum temperature of between 100° C. and 120° C.;

wherein the developing accelerator is a compound represented by the following formula (II):

wherein, in the formula (II), X 2 represents a hydrogen atom or a substituent, R 21 represents a hydrogen atom or substituent, and p denotes an integer from 0 to 4; and

said photosensitive material does not contain a super-high tone agent;

said reducing agent is represented by the following formula (VII):

wherein each of R 71 and R 71′ independently represents an alkyl group having 1 to 20 carbon atoms, each of R 72 and R 72′ independently represents a hydrogen atom or a substituent with which a benzene ring may be substituted, each of X 71 and X 71′ independently represent a hydrogen atom or a substituent with which a benzene ring may be substituted, L represents one of —S— and —CHR 73 — and R 73 represents one of a hydrogen atom and an alkyl group having 1 to 20 carbon atoms.

13 . The heat developing method according to claim 12 , wherein the heat-developable photosensitive material is heat-developed at a maximum temperature of 105° C. to 115° C.

14 . The heat-developable photosensitive material according to claim 12 , wherein the developing accelerator raises sensitivity at a density of 1.0 by 0.05 or more when 5 mol % of the reducing agent is substituted by the compound represented by formula (II).