Toyo Boseki Kabushiki Kaisha

Kazuo Katayose

Naoki Watanabe

Tooru Kitagawa

Takahiro Nakajima

Gaku Maruyama

Satoru Nakagawa

Fumikazu Yoshida

Kenta Susuki

Katsuhiko Kageyama

Kenichi Funaki

Masaki Fuchikami

Toshiyuki Tsuchiya

Haruhiko Kohyama

Makoto Ito

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

The present invention relates to such a polyamide resin composition that is suitably used as a material of a gasoline tank and a material of a molded article, such as a hollow molded container including a beverage bottle, a film and a sheet. A polyamide resin that is good in heat stability upon molding and suffers less increase in filter back pressure is provided by regulating a polyamide resin composition to have a phosphorus content of from 30 to 200 ppm (excluding 200 ppm), and a sodium content/phosphorus content ratio (molar ratio) of from 3 to 7 (excluding 3 and 7) or regulating it to have a phosphorus content less than 30 ppm and an alkali metal content less than 45 ppm.

Polyamide resin composition

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Tsuruga, Japan

Kazuo Katayose