Photothermographic material and image forming method

A photothermographic material comprising on a support a) an organic silver salt, b) a light-sensitive silver halide, c) a reducing agent, d) a compound represented by formula (1), 6-aryl-2,4-bis(tribromomethyl)-s-triazine or 6-heteroaryl-2,4-bis(tribromomethyl)-s-triazine, and e) an isocyanate compound:

• wherein X1, X2 and X3 are each a hydrogen atom or a substituent group, provided that at least one of X1, X2 and X3 is a halogen atom;
• L represents a sulfonyl group, a carbonyl group or a sulfinyl group;
• when L is a carbonyl group or sulfinyl group, n is 1, 2 or 3 and when L is a sulfonyl group, n is 0, 1, 2 or 3;
• when L is a carbonyl group or a sulfinyl group, Y is a single bond, —N(R1)—, an oxygen atom, a sulfur atom, a selenium atom, or —(R2)C═C(R3)—, when n is 2 or 3 and L is a sulfonyl group, Y is a single bond, —N(R1)—, an oxygen atom, a sulfur atom, a selenium atom, or —(R2)C═C(R3)—, and when n is 0 or 1 and L is a sulfonyl group, Y is —N(R1)—, an oxygen atom, a sulfur atom, a selenium atom, or —(R2)C═C(R3)—, in which R1, R2 and R3 are each a hydrogen or a substituent group;
• R is a hydrogen atom, a halogen atom, an aliphatic group, or R combines with R1 or R3 to form an alicyclic ring.