Toyo Boseki Kabushiki Kaisha

Yasutomi Yoshino

Tsutomu Isaka

Koichi Matsunami

Masahiro Kobayashi

Kunio Takeuchi

Tetsushi Murakami

Yukinobu Miyazaki

Haruo Okudaira

Fumio Nishimura

Haruhiko Watanabe

A process for production of a sheet of a polyamide material which comprises extruding the polyamide material in a melt state in the form of sheet and bringing the extruded sheet in a melt state into contact with the surface of a moving chill body for quenching to give an undrawn film, characterized in that a direct current of high voltage is applied between an electrode and the extruded sheet so as to product a discharge in a streamer corona state onto the extruded sheet, whereby the extruded sheet is brought into tight and close contact with the surface of the moving chill body electrically grounded so as to be chilled quickly.

Electrostatic pinning of extruded polyamide film

A transparent polyester film having excellent antistatic properties, which are little effected with variation of the humidity, and further having excellent flexing resistance, pinhole resistance and printability, which is made from a mixture comprising (i) a polyester consisting essentially of a residue of dibasic acids wherein at least 80% by mol is terephthalic acid and a residue of at least one glycol and (ii) a block copolyester consisting of a crystalline polyester segment having a high melting point and a soft polymer segment having a low melting point and a number average molecular weight of 400 to 8,000, said soft polymer segment having a low melting point being contained in an amount of 0.5 to 10% by weight on the basis of the whole weight of the components (i) and (ii), and (iii) a sulfonic and/or phosphoric acid metal salt having a good heat resistance, and which is produced by melt-extruding the mixture of the components (i), (ii) and (iii), drawing at least uniaxially and then heat-treating the resultant at a temperature of 170.degree. C. or higher and lower than the melting point of the polyester (i).

Polyester film

Growing community of inventors

Inuyama, Japan

Yasutomi Yoshino