Photothermographic material and image forming method using same

1 . A photothermographic material comprising a support, an image-forming layer, a non-photosensitive intermediate layer A, and an outermost layer,

wherein the image forming layer, the non-photosensitive intermediate layer A, and the outermost layer are disposed on the support in this order;

the image-forming layer comprises a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent, a polyhalogen compound, and a first binder;

the non-photosensitive intermediate layer A comprises a second binder in which a hydrophobic polymer constitutes 50% by mass or more of the second binder; and

the first binder in the image-forming layer comprises a copolymer including a monomer represented by formula (M-1) as a copolymerization component:

CH 2 ═CR 01 —CR 02 ═CH 2   Formula (M-1)

wherein in formula (M-1), R 01 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, or a cyano group; and R 02 represents an alkyl group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

2 . The photothermographic material according to claim 1 , wherein the non-photosensitive intermediate layer A is adjacent to the image-forming layer.

3 . The photothermographic material according to claim 1 , wherein the photothermographic material further comprises a non-photosensitive intermediate layer B between the non-photosensitive intermediate layer A and the outermost layer, and at least one of the outermost layer and the non-photosensitive intermediate layer B comprises a binder in which a hydrophilic polymer derived from an animal protein consitutes 50% by mass or more of the binder.

4 . The photothermographic material according to claim 1 , wherein the monomer represented by formula (M-1) constitutes 10 to 70% by mass of the copolymer, and a proportion of the copolymer including a monomer represented by formula (M-1) as a copolymerization component to the entire binder in the image-forming layer is 50% by mass or higher.

5 . The photothermographic material according to claim 1 , wherein the binder in the non-photosensitive intermediate layer A comprises a copolymer in which a monomer represented by formula (M) constitutes 10% by mass to 70% by mass of the copolymer:

CH 2 ═CR 01 —CR 02 ═CH 2   Formula (M)

wherein in formula (M), R 01 and R 02 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

6 . The photothermographic material according to claim 3 , wherein the non-photosensitive intermediate layer B comprises a third binder in which a hydrophilic polymer derived from an animal protein consitutes 50% by mass or more of the third binder, and the outermost layer comprises a fourth binder including a hydrophobic polymer.

7 . The photothermographic material according to claim 1 , wherein the photothermographic material further comprises two or more non-photosensitive intermediate layers B between the non-photosensitive intermediate layer A and the outermost layer; the non-photosensitive intermediate layers B include a first layer and a second layer; the first layer is nearer to the non-photosensitive intermediate layer A than the second layer is; the first layer includes a third binder in which a hydrophilic polymer that is not derived from an animal protein constitutes 50% by mass or more of the third binder, and the second layer includes a fourth binder in which a hydrophilic polymer derived from an animal protein constitutes 50% by mass or more of the fourth binder.

8 . The photothermographic material according to claim 7 , wherein the outermost layer comprises a binder including a hydrophilic polymer derived from an animal protein.

9 . The photothermographic material according to claim 7 , wherein the outermost layer comprises a binder including a hydrophobic polymer.

10 . The photothermographic material according to claim 7 , wherein the outermost layer comprises a binder including a hydrophilic polymer derived from an animal protein and a hydrophobic polymer.

11 . The photothermographic material according to claim 1 , wherein the reducing agent is a compound represented by formula (R1):

wherein in formula (R1), R 11 and R 11′ each independently represent a secondary or tertiary alkyl group having 1 to 15 carbon atoms; R 12 and R 12′ each independently represent a hydrogen atom or a substituent which can be bonded to the 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 which can be bonded to the benzene ring.

12 . The photothermographic material according to claim 1 , wherein the image-forming layer further comprises a development accelerator.

13 . The photothermographic material according to claim 1 , wherein the image-forming layer further comprises a compound represented by formula (D):

wherein in formula (D), R 21 to R 23 each independently represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, or a heterocyclic group.

14 . The photothermographic material according to claim 1 , wherein the image-forming layer further comprises a compound represented by formula (H):

Q-(Y) n —C(Z1)(Z2)X  Formula (H)

wherein in formula (H), Q represents an alkyl group, an aryl group, or a heterocyclic group; Y represents a divalent linking group; n represents 0 or 1; Z1 and Z2 each independently represent a halogen atom; and X represents a hydrogen atom or an electron-withdrawing group.

15 . The photothermographic material according to claim 14 , wherein the image-forming layer comprises two or more types of the compounds represented by formula (H).

16 . The photothermographic material according to claim 1 , wherein the image-forming layer further comprises a compound represented by formula (I):

wherein in formula (I), R represents a substituent; and m represents an integer of 1 to 6.

17 . The photothermographic material according to claim 16 , wherein the image-forming layer further comprises a color tone controlling agent.

18 . The photothermographic material according to claim 1 , wherein the non-photosensitive organic silver salt has a silver behenate content of 90 mol % or higher.

19 . The photothermographic material according to claim 1 , wherein the photothermographic material has an applied silver content of 1.3 g/m 2 or less.

20 . The photothermographic material according to claim 1 , wherein at least one layer disposed on the image-forming layer side of the support comprises a crosslinking agent.

21 . A method for forming an image on a photothermographic material comprising:

imagewise exposing a photothermographic of claim 1; and

heat-developing the exposed photothermographic material with a heating time of 16 seconds or less.

22 . A method for forming an image on a photothermographic material comprising:

imagewise exposing a photothermographic of claim 1; and

heat-developing the exposed photothermographic material while conveying the photothermographic material at 23 mm/sec or faster.

23 . The method for forming an image according to claim 21 , wherein the photothermographic material is conveyed at 23 mm/sec or faster in the heat development.