Patent ID: 6472138
Filing Date: 2002-10-29
Classification: G03C

Abstract:
A method for fabricating a black and white photothermographic material containing on one side of a support a reducing agent for reducing silver ion, a binder, a non-photosensitive fatty acid silver salt and a photosensitive silver halide, comprising:a step for preliminarily making a compound expressed by the formula (1) below adsorb to grains of the non-photosensitive fatty acid silver salt: [(Z)mL]nASM1â€ƒâ€ƒformula (1) â€ƒwhere, in the formula (1), Z represents â€”SO3M2, â€”COOR1, â€”OH or â€”NHR2; in which M2 being a hydrogen atom or an alkali metal atom, R1 being a hydrogen atom, an alkali metal atom or an alkyl group having 1 to 6 carbon atoms, R2 being a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, â€”COR4, â€”COOR4 or â€”SO2R4, in which R4 being a hydrogen atom, an aliphatic group or an aromatic group; m is an integer not less than 1, and for the case of m&gE;2, the groups Z in a number of m may be same or different with each other; L represents a single bond or a linkage group; n is an integer not less than 1, and for the case of n&gE;2, the groups (Z)mL in a number of n may be same or different with each other; A is a heterocyclic group which may be substituted; and M1 is a hydrogen atom or an alkali metal atom; a step for preparing the photosensitive silver halide grains having an average grain size of 10 nm to 50 nm; and a step for mixing the non-photosensitive fatty acid silver salt grains having the compound expressed by the formula (1) adsorbed thereon with the photosensitive silver halide grains.