Teijin Limited

Hirofumi Yoshikawa

Tamaki Kanai

Kenji Suzuki

Yoshikatsu Ohta

Takashi Yamagishi

Shiro Kumakawa

Sadayoshi Miura

Teruo Takahashi

Isao Hamana

Takashi Yamagichi

A polyester film having on at least one surface thereof a primer layer comprising a crosslinked product of a polyurethane having at least one functional group selected from a carboxyl group, a sulfo group, a hemisulfate group, and salts of these groups and a polyepoxy compound. The polyester film having a primer layer can be produced by coating an aqueous primer coating composition comprising a polyurethane having at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to drying, stretching and heat-treatment, and is useful as a base film for magnetic recording media.

Process for surface treating a polyester film

A process for producing a slippery biaxially stretched polyester film, which comprises coating one or both surfaces, preferably one surface, of a running polyester film, before the completion of its crystalline orientation, with an aqueous solution or dispersion containing

Process for the production of slippery biaxially stretched polyester

Slippery biaxially stretched polyester films

A process for producing an easily adherable biaxially stretched polyester film, which comprises coating a primer composition consisting of (A) and aqueous dispersion of polyurethane and (B) a montan wax salt and optionally a nonionic or anionic surface-active agent on the surface of a polyester film which has not yet been stretched completely, drying the coating, completing the stretching of the coated film, and then heat-setting it thereby to form a primer coated layer on the film surface.

Process for producing easily adherable polyester film

Textured polyester yarn is prepared from multifilament yarn composed of a synthetic linear ethylene terephthalate polyester by draw-texturing at a draw ratio of 1.05 - 1.30X, using a heat-setting temperature of about 170.degree. - 240.degree.. Feed yarn for said draw-texturing process has (a) a break elongation of 40 - 80%, (b) a density of above 1.371 g/cm.sup.3, and (c) a boil-off shrinkage of less than 8%. Said feed yarn is prepared by modified melt spinning of the foregoing polyester at a speed of about 3000 - 5000 meters per minute.

Draw-texturing polyester yarns

Growing community of inventors

Hachioji, Japan

Hirofumi Yoshikawa