A black and white photothermographic material comprising, on at least one side of a support, an image forming layer comprising at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, and a binder, wherein
- 50% or more of a total projected area of the photosensitive silver halide is occupied by tabular grains having a (111) face as a major face, the tabular grains have at least 2 parallel twin crystal planes in a grain, and a variation coefficient of a distribution of distances between closest twin crystal planes is 20% or less, wherein the grains are prepared by a nucleation step and a ripening step comprising a combination of plural means among following a) to d);
- a) in the presence of a gelatin having an average molecular weight of 50,000 or less,
- b) in the presence of a gelatin having a methionine content of 30 μmol or less per 1 g of the gelatin,
- c) at a temperature 0° C. to 30° C. during the nucleation step, and
- d) at a concentration of a silver nitrate solution and an alkali halide solution 0.01 mol/L to 0.8 mol/L during the nucleation step;
- and
- the image forming layer further comprises a nucleator represented by the following formulae (H), (G), (P), (A), (B) or (C);
- wherein in the formula (H). A0 represents an aliphatic group, an aromatic group, a heterocyclic group or a -G0-D0 group;
- B0 represents a blocking group, A1 and A2 both represent a hydrogen atom, or one represents a hydrogen atom and the other represents an acyl group or an oxalyl group;
- G0 represents a —COCO— group, a —CS— group, a —C(═NG1D1) group, an —SO— group, an —SO2— group or a —P(O)(G1D1)-group;
- G1 represents a mere bonding hand, an —O— group, an —S— group or an —N(D1)-group;
- D1 represents an aliphatic group, an aromatic group, a heterocyclic group, or a hydrogen atom;
- D0 represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group or an arylthio group;
- in the formula G, X represents an electron-attracting group, and W represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom, an acyl group, a thioacyl group, an oxalyl group, an oxyoxalyl group, a thiooxalyl group, an oxamoyl group, an oxycarbonyl group, a thiocarbonyl group, a carbamoyl group, a thiocarbamoyl group, a sulfonyl group, a sulfinyl group, an oxysulfinyl group, a thiosulfinyl group, a sulfamoyl group, an oxysulfinyl group, a thiosulfinyl group, a sulfinamoyl group, a phosphoryl group, a nitro group, an imino group, a N-carbonylimino group, a N-sulfonylimino group, a dicyanoethylene group, an ammonium group, a sulfonium group, a phosphonium group, a pyrylium group or an immonium group;
- R represents a halogen atom, a hydroxy group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkenyloxy group, an acyloxy group, an alkoxycarbonyloxy group, an aminocarbonyloxy group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, an alkenylthio group, an acylthio group, an alkoxycarbonylthio group, an aminocarbonyithic group, an organic or inorganic salt of hydroxy group or mercapto group, an amino group, an alkylamino group, a cyclic amino group, an acylamino group, an oxycarbonylamino group, a heterocyclic group, a ureido group or a sulfonamide group, in the formula (P), R1, R2, R3, and R4 each independently represent a hydrogen atom or a substituent, and X− represents an anion;
- R1 to R4 may bind to each other to form a cyclic structure;
- in the formulae (A) and (B), Z1 and Z2 each independently represent a nonmetallic atomic group cap able to form a 5 to 7-membered cyclic structure with —Y1—C(═CH—X1)—C(═O)— or with —Y2—C(═CH—X2)—C(Y3)═N—;
- X1 and X2 each independently represent a hydroxy group, an alkoxy group, an aryloxy aroup, a heterocyclic oxy group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alkylamino group, an arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamide group or a heterocyclic group;
- Y1 and Y2 each independently represent —CO— group or —SO2 — group;
- Y3 represents a hydrogen atom or a substituent;
- in the formula (C), X3 represents one selected from an oxygen atom, a sulfur atom or a nitrogen atom:
- Y4 represents the group represented by —C(═O)—, —C(═S)—, —SO—, —SO2—, —C(═NR3)— or —(R4)C═N═;
- Z3 represents a nonmetallic atomic group capable to form a 5 to 7-membered ring containing X3 and Y4;
- R1, R2, R3, and R4 each independently represent a hydrogen atom or a substituent:
- R1 and R2 do not bind to each other to form a cyclic structure.