Abstract: A polyester composition comprising 99.9 to 80 wt % of a thermoplastic polyester containing an antimony compound and 0.1 to 20 wt % of a partially aromatic polyamide, wherein a 4 mm-thick molded plate formed by molding the thermoplastic polyester at 290° C. has a haze value of 10% or lower, and wherein the phosphorus atom content in the partially aromatic polyamide (P1), the partially aromatic polyamide content in the polyester composition (A), and the antimony atom content in the thermoplastic polyester (S) satisfy a specific formula, wherein a 4 mm-thick molded plate produced by molding the polyester composition at 290° C. has a haze value of 20% or lower. The polyester composition can be molded into a hollow molded article (e.g., a bottle) at a high productivity rate, which is not deteriorated in transparency or color, and which is excellent in flavor-conserving property, thermal stability and gas-barrier property.

Abstract: A polyester resin that can be beneficially employed as one finding application in deactivation of polycondensation catalysts for polyester production and suppression of forming of acetaldehyde and other aldehydes and cyclic ester oligomers at molding stage. In particular, there is provided a polyester resin composed mainly of an aromatic dicarboxylic acid component and a glycol component wherein a phosphorus compound is incorporated through copolymerization or blending in an amount of 100 to 10,000 ppm in terms of phosphorus element, characterized in that the contents of Zn element, Fe element, Ni element and Cr element are not greater than specified values.

Abstract: The invention is a polyester resin mainly comprising a terephthalic acid component and a glycol component, wherein the fluorescence spectrum obtained by irradiating the polyester resin with excited light having a wavelength of 343 nm has a fluorescence intensity at 450 nm (B0) of 20 or lower. The resin makes it possible to efficiently produce a shaped article, especially a heat-resistant blow-molded article, that has excellent transparency and a moderate and stable crystallization rate and excellent heat-resistance dimensional stability, and is prevented from emitting fluorescence when irradiated with UV rays, and which is excellent in long-run continuous workability with no mold contamination, and which provides a wrapping material having excellent flavor retentiveness.

Abstract: The present invention relates to a polyester composition excellent in transparency, thermal stability, and flavor retention or excellent in transparency, thermal stability, flavor retention and gas barrier properties, which is obtained by blending a partially aromatic polyamide to a thermoplastic polyester, and also relates to a packaging material comprising the same. The polyester composition of the invention preferably contains an alkali metal atom in an amount of 0.1 to 300 ppm and phosphorus atom in an amount of 5 to 200 ppm. Further, it is preferable that the Color-L value of the molded article obtained by injection molding of the polyester composition of the invention at a molding temperature of 290° C. is 80.0 or more and the haze thereof is 20% or less. As the partially aromatic polyamide, an m-xylylene group-containing polyamide is preferable.

Abstract: The present invention provides a polyester resin composition comprising (A) 10 to 90% by weight of a polyethylene terephthalate polymer having 100 to 75 mole % of ethylene terephthalate units and (B) 90 to 10% by weight of a polyester resin wherein the polyester resin composition when molded into a sheet has an oxygen permeability coefficient of 3.0 or less cc-mm/m2day·atm. The polyester resin composition of the present invention gives a molded product which is outstanding in transparency, gas barrier property, ultraviolet-screening property and impact strength and therefore suitable as a reduced pressure blood-collecting tube.

Abstract: A polyester resin comprising a polyester resin chip (A) and a polyester resin fine particle (B) which has the same composition as the (A) and which passes through a 10.5 mesh screen in a proportion of 0.1-300 ppm, wherein a cyclic trimer increases in a proportion of not more than 0.30 wt % upon melting at a temperature of 290.degree. C. for 60 minutes; a polyester resin characterized in that a cyclic trimer increases in a proportion of not more than 0.30 wt % upon melting at a temperature of 290.degree. C. for 60 minutes, and the contents of Na, Ca, Mg and/or Si in the polyeser resin is 0.001-5 ppm and the total of these contents is not more than 10 ppm; and production methods thereof.