Unitika Ltd.

Hayami Ohnishi

Eiji Y Yamamoto

Minoru Kishida

Tsuneo Tamura

Katsuyuki Touma

Yoshiaki Kozuka

Hiroyuki Matsuda

Akira Menjyu

Shouji Nishimoto

A surface-roughened film and methods for fabricating same. The film has good transparency/exceptional clarity and high lubricity so that it is useful for a photoengraving material, label, packaging film, magnetic recording film, or clear film. The film has a composition including thermoplastic polyester resin (a) and a thermoplastic resin (b), such as an amorphous nylon, having glass transition temperature preferably 10.degree. C. higher than that of the thermoplastic polyester resin (a) and a critical surface tension more than 0.1 dyne/cm different from that of the thermoplastic polyester resin (a). Resin (b) further has a melt viscosity, at a temperature of 280.degree. C. and shear rate of 10.sup.2 sec.sup.-1, in the range of 500 to 50,000 poise. One or more particulate inert inorganic compound may be added and the film may be laminated to layers of other polymers with the film of the foregoing composition on at least one surface thereof. On the film surface, microprotuberances cored with the thermoplastic resin (b) are formed. In addition, there are also provided methods for fabricating the surface-roughened film including drawing the film in at least one direction by a factor of at least one and one-half at a temperature between Tg of (a) and Tg of (b).

Surface-roughened polyester film

Growing community of inventors

Kyoto, Japan

Hayami Ohnishi