Heat developable light sensitive material and image forming method

#1. Field of the Invention

#The present invention concerns a heat developable light sensitive material excellent in photographic performance and transportability and, particularly, suitable to use for medical diagnosis, as well as an image forming method using the light sensitive material.

#2. Description of the Related Art

#The present invention will be described specifically by way of examples but the invention is not restricted to such examples.

#After adding simultaneously a solution prepared by dissolving 27.4 g of KBr and 3.3 g of KI in 275 ml of deionized water and a solution prepared by dissolving 42.5 g of silver nitrate in 364 ml of deionized water to a first solution prepared by dissolving 30 g of gelatin phthalide and 71.4 mg of KBr in 1500 ml of deionized water and adjusting its pH to 5.0 by 3 mol/l of nitric acid and kept at 34° C., over 9.5 minutes, a solution prepared by dissolving 179 g of KBr and 10 mg of dipotassium hexachloroiridate in 812 ml of deionized water and a solution formed by dissolving 127 g of silver nitrate in 1090 g of deionized water were mixed therewith simultaneously for 28.5 min. Further, pAg was kept at a constant value by using a pAg feedback control loop as described in Research Disclosure No. 17643, U.S. Pat. Nos. 3,415,650, 3,782,954 and 3,821,002.

#The thus obtained emulsion was washed with water and desalted. The average particle size was 0.045 μm. The size of the silver halide grains was determined by a transmission electron microscope (TEM).