Toyo Boseki Kabushiki Kaisha

Shigeto Yoshida

Naonobu Oda

Hisato Kobayashi

Tadashi Okudaira

Keizo Kawahara

Masayuki Tsutsumi

Kazutake Okamoto

Katsufumi Kumano

Keiji Mori

Kazumoto Imai

Akira Takahashi

Akinobu Nagara

Shinsuke Yamaguchi

Eiji Kumagai

Yoshiko Akitomo

An oriented syndiotactic polystyrene-based film composed of an oriented film made of a syndiotactic styrene polymer and an adhesiveness-improving layer formed from a specific water-dispersible resin on at least one surface of the oriented film, which is excellent in the tight adhesion between the oriented film and the adhesiveness-improving layer, the adhesion between the adhesiveness-improving layer and an ink layer or laminate layer applied thereon, economical efficiency, recyclability, and environmental compatibility in production. It is particularly preferable that the film be produced by applying the aqueous dispersion of the water-dispersible resin on unstretched or uniaxially stretched film to form the adhesiveness-improving layer, stretching the obtained laminate uni- or bi-axially at least one time, and then heat-treating the resulting laminate.

Oriented syndiotactic polystyrene-base film

An aliphatic polyester film comprising, as a main component, a polylactic acid having a reduced viscosity (&eegr;sp/C) of not less than 0.50 dl/g and not more than 2.50 dl/g, wherein the film has a thermal shrinkage in the longitudinal direction at 120&deg; C. of not more than 5.0% is provided. The aliphatic polyester film of the present invention is provided which is useful as a packaging film and an adhesive tape, superior in hand tearability, twist retention, processability and film forming property, and which is biodegradable when placed in a natural environment.

Aliphatic polyester film

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Ohtsu, Japan

Shigeto Yoshida