| 摘要 |
A biaxially oriented sheet of a biodegradable thermoplastic resin composition containing a lactic acid polymer is used as a structural material for a supporting substrate (2) of a biodegradable card (1). The lactic acid polymer has a number average molecular weight of from 10,000 to 1,000,000. The thermoplastic resin composition may preferably be mixed with a modifying biodegradable resin. In another embodiment, the biaxially oriented sheet of the biodegradable thermoplastic resin composition may preferably be covered with the modifying biodegradable resin. The biodegradable lactic acid polymer or the modifying biodegradable resin is also used as a polymeric binder of an information recording layer (3) provided on the surface of the supporting substrate (2). <MATH> |
