Heat-developable photosensitive material and image-forming process

1. A heat-developable photosensitive material comprising, on one surface of a support, at least one photosensitive silver halide, a reducing agent for silver ions, a binder, non-photosensitive organic silver salt particles, and at least one development accelerator,

the non-photosensitive organic silver salt particles including silver behenate in a content of from 90% by mole to 99.9% by mole based on the non-photosensitive organic silver salt particles,

wherein the development accelerator is a compound in which, when added in an amount of 5% by mole relative to the reducing agent, exposure amount required to obtain an optical density=1.0 is reduced to 90% or less, as compared to the case where the compound is not added,

wherein the development accelerator comprises at least one of compounds represented by the following formulae (1) and (4):

 wherein, in formula (1): R 1 represents an alkyl group, aryl group, alkenyl group, heterocyclic group, acyl group, alkoxycarbonyl group, carbamoyl group or alkynyl group; X 1 represents an acyl group, alkoxycarbonyl group, carbamoyl group, sulfonyl group or sulfamoyl group; and Y 1 , Y 2 , Y 4 and Y 5 each independently represents a hydrogen atom or a substituent, and

in formula (4): X 1d represents a substituent; X 2d , X 3d and X 4d each independently represents a hydrogen atom or a substituent; none of X 1d , X 2d , X 3d and X 4d is a hydroxy group; X 3d is not a sulfonamide group; substituents represented by X 1d , X 2d , X 3d and X 4d may be bonded to each other to form a ring; and R 1d represents a hydrogen atom, alkyl group, aryl group, heterocyclic group, amino group or alkoxy group.

2. The material of claim 1 , wherein the non-photosensitive organic silver salt particles comprise silver arachidate in a content of from 0% by mole to 6% by mole based on the non-photosensitive organic silver salt particles.

3. The material of claim 1 , wherein the content of silver behenate in the non-photosensitive organic silver salt particles is from 95% by mole to 99.9% by mole based on the non-photosensitive organic silver salt particles.

4. The material of claim 1 , wherein the content of silver behenate in the non-photosensitive organic silver salt particles is from 97% by mole to 99.9% by mole based on the non-photosensitive organic silver salt particles.

5. The material of claim 1 , wherein the non-photosensitive organic silver salt particles are prepared by a process that includes adding an aqueous silver nitride solution and a solution or suspension of an alkali metal salt of an organic acid to a closed mixing container.

6. The material of claim 1 , wherein the non-photosensitive organic silver salt particles have been desalted by an ultrafiltration method.

7. The material of claim 1 , wherein at least some of the non-photosensitive organic silver salt particles are contained in a layer prepared from a coating solution, the coating solution including a solvent including water in a content of at least 80% based on the solvent.