PURPOSE: To enhance the resistance to heat, chemicals, moisture and impact, the transparency, resistance to optical rotation and fidelity in molding by forming a magnetic layer which can be changed by energy on one side of an optically transparent plate made of a polymer composition.
CONSTITUTION: A magnetic layer 5 which can be changed by light energy is formed on one side of an optically transparent plate 4 made of a polymer composition contg. repeating units represented by the formula, and a metallic coating layer 7 is formed on the exposed side of the layer 5. Information is reproduced by irradiating laser light from the reverse side of the layer 7. The polymer composition contg. repeating units represented by the formula is poly-(N-ethylene trimellitic imide) resin, a copolymer contg. the repeating units, or a polymer blend of a copolymer contg. the repeating units with other polymer.
ICHIKAWA RINJIROU
UNO KEIICHI
