Toyo Boseki Kabushiki Kaisha

Katsuhiko Kageyama

Naoki Watanabe

Takahiro Nakajima

Fumikazu Yoshida

Tooru Kitagawa

Shoichi Gyobu

Yoshitomo Ikehata

Satoru Nakagawa

Maki Sato

Masaou Matsuda

Mitsuyoshi Kuwata

Yoshinao Matsui

Nobuo Moriyama

Haruo Matsumoto

Kazuo Katayose

Hiroki Fukuda

Kenichi Tsukamoto

Kenichi Funaki

Masaki Fuchikami

Munekazu Okuhara

Toshiyuki Tsuchiya

Haruhiko Kohyama

This invention provides a polyester and a polyester molded product, which, while maintaining color tone, transparency, and thermal stability, can realize a high polycondensation rate, are less likely to cause the production of polycondensation catalyst-derived undesired materials, and can simultaneously meet both quality and cost effectiveness requirements, which can exhibit the characteristic features, for example, in the fields of ultrafine fibers, high transparent films for optical use, or ultrahigh transparent molded products. These advantages can be realized by using, in the production of a polyester in the presence of an aluminum compound-containing polyester polycondensation catalyst, an aluminum compound having an absorbance of not more than 0.0132 as measured in the form of an aqueous aluminum compound solution, prepared by dissolving the aluminum compound in pure water to give a concentration of 2.7 g/liter in terms of the amount of aluminum element, under conditions of cell length 1 cm and wavelength 680 nm.

Process for producing polyester, polyester produced using said process, and polyester molded product

A polymerization catalyst for polyester production which contains neither a germanium compound nor an antimony compound as a major component. It contains aluminum as the main metallic ingredient, has excellent catalytic activity, and gives a polyester which is effectively inhibited from suffering thermal degradation, during melt molding, without deactivating or removing the catalyst, and is excellent in thermal stability, stability to thermal oxidation, and hydrolytic resistance. The polymerization catalyst contains as a first metallic ingredient at least one member selected among aluminum and compounds thereof and further contains a phosphorus compound represented by a specific chemical formula. The polyester produced with this catalyst is usable as fibers, films, sheets, various moldings including hollow moldings, etc.

Polymerization catalyst for polyester, polyester produced with the same, and process for producing polyester

Growing community of inventors

Tsuruga, Japan

Katsuhiko Kageyama