| 摘要 |
PURPOSE:To maintain secrecy by combining a recording agent contg. photochromic dyestuffs and a recording material provided with a recording surface having the color tone substantially equal to the color tone of this recording agent under white light and visualizing the recording part formed on the recording material by irradiation with UV rays and/or heat rays. CONSTITUTION:A soln., emulsion or suspension dissolved with the recording agent 3 contg. the photochromic dyestuffs 1 is preped. This liquid is written by a writing means, such as pen and writing brush or by a writing means, such as pencil after this liquid is made into a solid state, on the recording material 2 which is a sheet or plate having the recording layer of the color tone substantially equal to the color tone of the recording agent, by which the recording part 4 is formed. The recording medium suitable for forming the recording part 4 which can be visualized by the change in the color tone of the photochromic dyestuffs 1 by the UV rays or heat rays 6 is constituted in such a manner. This recording agent 3 is sufficient with the extremely thin layer in the state of being applied on the recording material 2 and cannot be visually checked. The recording medium formed by using the photochromic dyestuffs can assure the secrecy of information in this way. |
