Teijin Limited

Masami Umeda

Kimihiko Sato

Minoru Suzuki

Hiroki Nagano

Noriyuki Akagi

Kazumoto Miyajima

Naonobu Tadokoro

Ethylene terephthalate/ethylene-2,6-naphthalene-dicarboxylate copolymers

A container formed from a copolyester composition which comprises a copolyester containing 80 to 95 mol % of terephthalic acid and 20 to 5 mol % of 2,6-naphthalenedicarboxylic acid as acid components and ethylene glycol as a glycol component, wherein catalyst metals of a calcium compound, magnesium compound and cobalt compound are contained in the copolyester in such amounts that satisfy all the following expressions (1) to (4) based on the total of the whole acid component of the polymer:

Container formed from copolyester composition, copolyester composition

A polyethylene-2,6-naphthalene dicarboxylate resin for molding a bottle, which comprises 2,6-naphthalenedicarboxylic acid as a main acid component and ethylene glycol as a main glycol component and contains a germanium compound as a polycondensation catalyst, and has an intrinsic viscosity of 0.55 to 0.75 dl/g, a terminal carboxyl group content of 32 eq/ton or less, an acetaldehyde content of 8 ppm or less and a diethylene glycol component content of 0.8 to 3.0 wt %.

Polyethylene-2,6-naphthalene dicarboxylate resin and preform and bottle

A loose tube for an optical fiber comprising a polybutylene terephthalate. The polybutylene terephthalate has a terminal carboxyl group concentration of 10 eq./10.sup.6 g.multidot.polymer or less and an intrinsic viscosity �.eta.!, measured at 25.degree. C. in orthochlorophenol, of 0.9 to 1.4 dl/g.

Polybutylene terephthalate having low carboxyl group concentration and

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Matsuyama, Japan

Masami Umeda