Patent ID: 7488572

Claim:
An image formation method comprising: exposing a photothermographic material having an image-forming layer comprising at least one hydrophobic transparent binder and a back layer with a light having a wavelength of 700-850 nm and subjecting the exposed photothermographic material to development in a heat development apparatus provided with a preheating section, a heat development section and a gradual cooling section, wherein the image forming layer is obtained by applying a coating solution containing 50 weight % or more of an organic solvent based upon the total weight of solvent in the coating solution, and the heat development section is provided with heating members on the image-forming layer side and the back layer side and transportation rollers only on the image-forming layer side with respect to the phototherimographic material to be transported in the apparatus, and at least one layer constituting the photothermographic material contains at least one high contrast agent selected from the group consisting of hydrazine derivatives, quaternary ammonium compounds, quaternary phosphonium compounds and at least one high contrast agent represented by the following formula (e): wherein R e1 represents an electron-withdrawing group, R e2 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, an —S-carbonyl group, a carbamoyl group, a thiocarbamoyl group, a sulfonyl group, a sulfinyl group, an oxysulfonyl group, a thiosulfonyl group, a sulfamoyl group, an oxysulfinyl group, a thiosulfinyl group, a sulfinamoyl group, a phosphoyl group, a nitro group, an imino group, an N-carbonylimino group, an N-sulfonylimino group, a dicyanoethylene group, an ammonium group, a sulfonium group, a phosphonium group, a pyrylium group, or an immonium group, R e3 represents a halogen atom, a hydroxy group or a salt thereof, an alkoxy group, an aryloxy group, a heterocyclyloxy group, an acyloxy group, an alkenyloxy group, an alkynyloxy group, an alkoxycarbonyloxy group, an aminocarbonyloxy group, a mercapto group or a salt thereof, an alkylthio group, an arylthio group, a heterocyclylthio group, an alkenylthio group, an alkynylthio group, an acylthio group, an alkoxycarbonylthio group, an aminocarbonylthio group, an amino group, an alkylamino group, an arylamino group, an acylamino group, an oxycarbonylamino group, a ureido group, or a sulfonamido group, and the trans-configuration between R e1 and R e3 is also included in the scope of the formula (e).