Packaged member of photothermographic material and image forming method for photothermographic material

1 . A packaged member which comprises a photothermographic material and a packaging bag, wherein

an interior of the packaging bag into which the photothermographic material is packed has a humidity of 50% RH or less at 25° C.,

the photothermographic material includes, on one surface of a substrate, an image forming layer comprising a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, and

at least one of the following conditions (1) to (4) is satisfied:

(1) 50 mass % or more of the binder is a polymer having a glass transition temperature from 70 to 110° C.;

(2) 50 mol. % or more of the non-photosensitive organic silver salt is silver behenate;

(3) the reducing agent is a compound represented by the following Formula (B):

wherein R 11 and R 11′ each independently represent a secondary or tertiary alkyl group having 3 to 15 carbon atoms; R 12 and R 12′ each independently represent a hydrogen atom or a substituent on a benzene ring; L represents an —S— group or a CHR 13 — group; R 13 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and X 1 and X 1′ each independently represent a hydrogen atom or a substituent on a benzene ring; and

(4) the photothermographic material includes a development accelerator.

2 . The packaged member of claim 1 , wherein the condition (1) is satisfied.

3 . The packaged member of claim 1 , wherein the condition (2) is satisfied.

4 . The packaged member of claim 1 , wherein the condition (3) is satisfied.

5 . The packaged member of claim 1 , wherein the condition (4) is satisfied.

6 . The packaged member of claim 1 , wherein the conditions (1) and (2) are satisfied.

7 . The packaged member of claim 1 , wherein the conditions (1), (2) and (3) are satisfied.

8 . The packaged member of claim 1 , wherein the conditions (1), (2), (3) and (4) are satisfied.

9 . The packaged member of claim 1 , wherein the interior of the bag has a humidity of 10 to 40% RH at 25° C.

10 . The packaged member of claim 1 , wherein the photothermographic material immediately after being taken out from the bag has a water content of 3 mass % or less at 25° C.

11 . The packaged member of claim 1 , wherein the binder includes polyvinyl acetal.

12 . The packaged member of claim 1 , wherein a coating liquid for forming the photothermographic material includes an organic solvent.

13 . The packaged member of claim 1 , wherein the image forming layer contains silver in an amount of 1.9 g/m 2 or less.

14 . A image forming method which comprises exposing a photothermographic material and thermally developing the photothermographic material within a developing time from 1 to 60 seconds, wherein

the photothermographic material is packaged in a packaging bag before being exposed,

an interior of the packaging bag has a humidity of 50% RH or less at 25° C.,

the photothermographic material includes, on one surface of a substrate, an image forming layer comprising a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, and

at least one of the following conditions (1) to (4) is satisfied:

(1) 50 mass % or more of the binder is a polymer having a glass transition temperature from 70 to 110° C.;

(2) 50 mol. % or more of the non-photosensitive organic silver salt is silver behenate;

(3) the reducing agent is a compound represented by the following Formula (B):

wherein R 11 and R 11′ each independently represent a secondary or tertiary alkyl group having 3 to 15 carbon atoms; R 12 and R 12′ each independently represent a hydrogen atom or a substituent on a benzene ring; L represents an —S— group or a CHR 13 — group; R 13 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and X 1 and X 1′ each independently represent a hydrogen atom or a substituent on a benzene ring; and

(4) the photothermographic material includes a development accelerator.

15 . The image forming method of claim 14 , wherein the thermal developing is conducted within a developing time from 3 to 13 seconds.

16 . The image forming method of claim 14 , wherein the thermal developing utilizes a heat drum and is executed by heating the photothermographic material from a side of the substrate at which photosensitive silver halide and the non-photosensitive organic silver salt are disposed.