Black and white photothermographic material

Abstract

The present invention provides a black and white photothermographic material having, on at least one side of a support, at least a photosensitive silver halide, a non-photosensitive organic silver salt, a color developing agent, and a coupler which reacts with an oxidation product of the color developing agent to form a dye, wherein a mean particle size of the non-photosensitive organic silver salt is 0.38 μm or less. A black and white photothermographic material which exhibits high sensitivity, high density, excellent image tone, and excellent coating ability is provided.

Description

Claims

1. A black and white photothermographic material comprising, on at least one side of a support, at least a photosensitive silver halide, a non-photosensitive organic silver salt, a color developing agent, and a coupler which reacts with an oxidation product of the color developing agent to form a dye, wherein a mean particle size of the non-photosensitive organic silver salt is 0.38 μm or less.

2. The black and white photothermographic material according to claim 1, wherein a variation coefficient of a particle size distribution of the non-photosensitive organic silver salt is 50% or less.

3. The black and white photothermographic material according to claim 1, wherein an image density formed by imagewise exposing and thermally developing the black and white photothermographic material satisfies the following equation (A): 0.02<Dc<D/4   Equation (A)wherein D represents an optical density in a range of from 1.0 to 2.0; and Dc represents an optical density obtained by the dye in the optical density.

4. The black and white photothermographic material according to claim 1, wherein the color developing agent is a compound represented by the following formula (1):

5. The black and white photothermographic material according to claim 1, wherein the coupler is at least one compound represented by a formula selected from the group consisting of the following formulae (C-1), (C-2), (C-3), (M-1), (M-2), (M-3), (Y-1), (Y-2), and (Y-3):

6. The black and white photothermographic material according to claim 5, wherein, in formulae (C-1), (C-2), (C-3), (M-1), (M-2), (M-3), (Y-1), (Y-2), and (Y-3), X1, X2, X3, X4, X5, X6, X7, X8, and X9 are each a hydrogen atom.

7. The black and white photothermographic material according to claim 5, wherein the coupler is a compound represented by formula (C-1):

8. The black and white photothermographic material according to claim 7, wherein, in formula (C-1), X1 is a hydrogen atom.

9. The black and white photothermographic material according to claim 1, wherein the black and white photothermographic material further comprises a reducing agent for silver ions which is represented by the following formula (R1):

10. The black and white photothermographic material according to claim 9, wherein the black and white photothermographic material comprises, on one side of the support, a first image forming layer comprising at least the photosensitive silver halide, the non-photosensitive organic silver salt, and the reducing agent for silver ions, and a second image forming layer comprising at least the coupler, and at least one of the first image forming layer or the second image forming layer comprises the color developing agent.

11. The black and white photothermographic material according to claim 10, wherein the first image forming layer is a photosensitive silver image forming layer, and the second image forming layer is a non-photosensitive color image forming layer.

12. The black and white photothermographic material according to claim 11, wherein the second image forming layer comprises the color developing agent.

13. The black and white photothermographic material according to claim 11, wherein the second image forming layer further comprises the reducing agent for silver ions.

14. The black and white photothermographic material according to claim 10, wherein 40% by weight or more of a binder for the first image forming layer is a polymer latex, and 40% by weight or more of a binder for the second image forming layer is a polymer latex.

15. The black and white photothermographic material according to claim 14, wherein the polymer latex is a polymer latex comprising a monomer component represented by the following formula (M) within a range of from 10% by weight to 70% by weight: Formula (M) CH2═CR01—CR02═CH2 wherein R01 and R02 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

16. The black and white photothermographic material according to claim 15, wherein, in formula (M), both of R01 and R02 are a hydrogen atom, or one of R01 or R02 is a hydrogen atom and the other is a methyl group.