THERMALLY DEVELOPING PHOTOGRAPHIC MATERIAL Russian patent published in 2001 - IPC

FIELD: light-sensitive materials. SUBSTANCE: material represents transparent film of water- permeable polymer containing polyvinyl alcohol or gelatin with lead acetate as light-sensitive additive. Material is sensitive to light with wavelength <300 nm. When exposed to mercury lamp at room temperature for a few minutes and heated to 80-100 C, material loses its transparency and acquires milk-white color. After moistening with water, exposed regions restore their transparency and became fit for performing further records on them. Light sensitivity of material is restored by retreatment with lead acetate. When exposed but not subjected to heat development specimen is moistened, hidden image is first developed and then disappears. Material can be utilized in removable optical information recording systems. EFFECT: enabled repetitive records of optical information. 3 ex