Gunze Limited

Mamoru Oishi

Akira Morikawa

Yoshikiyo Saito

The present invention provides a card base which is degradable by microbes in natural environment. The card base is excellent in properties necessary for card bases, such as tensile strength, impact strength, flex temperature, heat resistance, resistance to thermal expansion and contraction, blocking resistance and humidity resistance, and has rigidity, bending resistance and durability. The card base contains, as essential components, a 3-hydroxybutylate/3-hydroxyvalerate copolymer and a lactic acid polymer, and, where necessary, a polycaprolactone or a high-molecular aliphatic polyester. The card base has a single-layer structure, or a sandwich structure further having overlay layers comprising a composition containing, as essential components, a lactic acid polymer and either or both of a polycaprolactone and a high-molecular alphatic polyester.

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Moriyama, Japan

Mamoru Oishi