Mitsubishi Chemical Corporation

Yoshihiro Fujimori

Yutaka Yatsugi

Masahiro Nukui

Toshiyuki Hamano

Katsuji Tanaka

Kazuyoshi Mino

Kiyotoshi Fujioka

Kazuya Nakamichi

Noboru Satou

Kenichi Matsui

Shuuji Anno

Takashi Nakamura

Hitoshi Matsumoto

Toshio Kambe

Michiko Yoshida

Tetsuya Sugita

Jouji Akiyama

Hirotsugu Niwa

Syuji Anno

Provided in this invention are polyethylene terephthalate resins which can suppress the formation of acetaldehyde as a by-product in melt molding of the resins and can provide the molded products reduced in acetaldehyde content. A polyethylene terephthalate resin which has an intrinsic viscosity [&#x3b7;] of not less than 0.70 dl/g and not more than 1.50 dl/g and an acetaldehyde content [AA(ppm by weight)] of not more than 10 ppm by weight, and has such properties that the acetaldehyde content [AA(ppm by weight)] of the molded product obtained by injection molding the resin at 280&#xb0; C. with its moisture content adjusted to 30&#xb1;20 ppm by weight and the acetaldehyde content [AA(ppm by weight)] of the molded product obtained by injection molding the resin at 280&#xb0; C. with its moisture content adjusted to 120&#xb1;20 ppm by weight satisfy the following formula (1):[()/]&#xd7;100&#x2267;30&#x2003;&#x2003;(1).

Polyethylene terephthalate resins and process for producing polyester resin moldings

A process for producing a polyester using a catalyst, which catalyst enables producing a polyester excellent in color tone and transparency at a high reaction velocity; the catalyst; and a method for producing the catalyst, which catalyst comprises:

Polymerization catalyst for polyester, method for producing it and process for producing polyester using it

Polymerization catalysts for polyesters include: (1) metal elements selected from metal elements of Group 4A of the Periodic Table; and (2) metal elements selected from metal elements of Group 2A of the Periodic Table, aluminum, manganese, iron, cobalt, zinc, gallium and germanium. The catalysts are in a liquid state with a turbidity of at most 20% in a light path length of 10 mm, and a ratio the total amount of metal atoms derived from the above metal element (2) to the total amount of metal atoms derived from the above metal element (1) is from 0.50 to 3.50.

A polyester resin produced by polycondensing a dicarboxylic acid component containing an aromatic dicarboxylic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of at least an antimony compound and a phosphorus compound, via an esterification reaction or an ester exchange reaction, which is characterized in that the amount of antimony eluted when immersed in hot water of 95&#xb0; C. for 60 minutes in the form of particles having a number average particle weight of 24 mg, is not more than 1 &#x3bc;g per 1 g of the polyester resin, as antimony atoms (Sb).

Polyester resin, molded product made thereof and process for production of polyester resin

A polyester resin characterized in that the content of the copolymerized components other than the terephthalic acid component and the ethylene glycol component, is not more than 4 mol % based on the total discarboxylic acid component, and when polyester resin is formed into a molded product, the molded product has a specific absorbance.

Polyester resin and process for its production

A polyester resin produced by polycondensing a dicarboxylic acid component containing an aromatic dicarboxylic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of at least an antimony compound and a phosphorus compound, via an esterification reaction or an ester exchange reaction, which is characterized in that the amount of antimony eluted when immersed in hot water of 95&deg; C. for 60 minutes in the form of particles having a number average particle weight of 24 mg, is not more than 1 &mgr;g per 1 g of the polyester resin, as antimony atoms (Sb).

A polyester resin is prepared by polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction or an ester exchange reaction, wherein the content of copolymerized components other than the terephthalic acid component and the ethylene glycol component, is not more than 4 mole % based on the total dicarboxylic acid component, and in a molded product with a thickness of 3.5 mm injection-molded at 280&deg; C., the difference between the absorbance at a wavelength of 395 nm and the absorbance at a wavelength of 800 nm is at least 0.08, and the difference between the absorbance at a wavelength of 500 nm and the absorbance at a wavelength of 800 nm is at most 0.05.

Polyester resin and its production process

Disclosed are a polyester mainly composed of an aromatic dicarboxylic acid as an acid component and an aliphatic diol as a diol component, wherein the content of an antimony element in the polyester is from 50 to 350 ppm, the number of metallic antimony particles having a diameter of 0.5 &mgr;m or more is 30,000 or more per 100 mg of polyester, the ratio of the number of fine particles having a diameter of 0.5 &mgr;m to less than 0.6 &mgr;m is 70% or more, and the L value in hue is 80 or more; a stretch blow molded product formed of the polyester; and a method for producing a polyester mainly composed of an aromatic dicarboxylic acid as an acid component and ethylene glycol as a diol component which comprises adding a preliminary mixed catalyst solution of an antimony compound and a trivalent phosphorus compound as a catalyst, the catalyst solution having a haze of 10% or less, at a stage showing an acid value of 1,000 eq/ton or less before initiation of melt polymerization.

Polyester, stretch blow molded product formed thereof and method for producing polyester

A polyester which is characterized in that

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Yokkaichi, Japan

Yoshihiro Fujimori