| 摘要 |
PURPOSE:To obtain a photochromic recording material which is remarkably improved in a contrast ratio, high density recording, thermal stability, long- period stability and repetitive use times by shutting off the recorded part thereof from the air to maintain the record and permitting erasing of the record by bringing the recorded part into contact with the air. CONSTITUTION:Writing of information is executed by irradiating light on the recording material formed by coating a coating liquid contg. a heteropolytungstic acid and/or the salt thereof to one face of an optical material and curing the coating, then further bringing the optical material into tight contact with the coating surface. The erasing of the information is executed by removing the optical material which is brought into tight contact with the coated surface to expose the coated surface to the atm. or oxygen. The contrast ratio, durability, repetitive characteristic, high density recording, long-period shelf life and ease of use are thus made excellent. |
