| 摘要 |
<p>PURPOSE:To make a magnetic card decomposable in the natural environment while possessing durability, by a method wherein a magnetic layer is provided on at least one side of non-magnetic substrate which is constituted of a polyester to be obtained from an aliphatic alpha-oxyacid. CONSTITUTION:A magnetic layer is provided at least on one side of a non- magnetic substrate and at least a part of the substrate is constituted of a polyester to be obtained from an aliphatic alpha-oxyacid and a magnetic card is obtained therefrom. The foregoing polyester is the polyester to be obtained from the aliphatic alpha-oxyacid and glycol acid or L-lactic acid is suitable as the aliphatic alpha-oxyacid. Therefore, the suitable polyester is a polymer of the aliphatic alpha-oxyacid to be selected out of the glycol acid and L-lactic acid and a homopolymer of the glycol acid or homopolymer of the L-lactic acid is available. Since the substrate possesses sufficient strength and the modulus of elasticity as a card substrate, the substrate possesses durability.</p> |
