Abstract: An alicyclic polyester which is suitable for use as an optical material, low in coloration, satisfactory in thermal stability and hydrolytic stability, and reduced in foreign-matter content; and a resin composition comprising the alicyclic polyester and a polycarbonate. The alicyclic polyester is produced from a dicarboxylic acid ingredient comprising an alicyclic dicarboxylic acid as a major component and a diol ingredient comprising an alicyclic diol as a major component with the aid of a polycondensation catalyst comprising a titanium compound and an alkaline earth metal compound. The alicyclic polyester has a titanium content in terms of metal atom amount of 1-25 wt. ppm, excluding 25 wt. ppm, a ratio of the weight of the alkaline earth metal (M) to the weight of the titanium in terms of metal atom amount ratio, (M/Ti), of 0.25-1.0, and an intrinsic viscosity of 0.4 dl/g or higher.

Abstract: 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 dicarboxylic acid component, and when polyester resin is formed into a molded product, the molded product has a specific absorbance.

Abstract: 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° C. for 60 minutes in the form of particles having a number average particle weight of 24 mg, is not more than 1 ?g per 1 g of the polyester resin, as antimony atoms (Sb).

Abstract: A polyester resin, whereby a molded product excellent in a gas barrier property and also excellent in an ultraviolet shielding property, a color tone, etc., and which is particularly suitable for molding a bottle for e.g. a beverage required to have an aroma retention property, and further, a polyester resin, whereby the acetaldehyde content as a molded product is reduced to eliminate an influence over the taste, aroma, etc. of the content, and a process for its production, wherein the polycondensability is improved, are to be presented.

Abstract: 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.

Abstract: 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° 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).

Abstract: 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° 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).

Abstract: A polyester resin, whereby a molded product excellent in a gas barrier property and also excellent in an ultraviolet shielding property, a color tone, etc., and which is particularly suitable for molding a bottle for e.g. a beverage required to have an aroma retention property, and further, a polyester resin, whereby the acetaldehyde content as a molded product is reduced to eliminate an influence over the taste, aroma, etc. of the content, and a process for its production, wherein the polycondensability is improved, are to be presented.

Abstract: 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° 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.

Abstract: The present invention provides a process for the preparation of a novel toner satisfying a high resolution, a low temperature fixability and a high offset resistance at a low cost. A novel toner for the development of an electrostatic image is provided comprising an agglomerate of particles containing at least primary polymer particles, wherein said primary polymer particles substantially comprise a wax encapsulated therein.

Abstract: 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° 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).

Abstract: 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 dicarboxylic acid component, and when polyester resin is formed into a molded product, the molded product has a specific absorbance.

Abstract: The present invention provides a process for the preparation of a novel toner satisfying a high resolution, a low temperature fixability and a high offset resistance at a low cost. A novel toner for the development of an electrostatic image is provided comprising an agglomerate of particles containing at least primary polymer particles, wherein said primary polymer particles substantially comprise a wax encapsulated therein.

Abstract: The present invention relates to a polyester resin produced by polymerizing a dicarboxylic acid component comprising mainly an aromatic dicarboxylic acid or its ester forming derivative, and a diol component comprising mainly ethylene glycol in the presence of a catalyst containing a titanium compound, which polyester resin contains titanium atoms (Ti) in an amount of 0.002 to 1.0 mole based on one ton of the polyester resin and has the following properties: Intrinsic viscosity ([&eegr;], dl/g)≧0.70 Hunter's “b” value≦4 Acetaldehyde content (AA0, ppm)≦5.0.

Abstract: The present invention provides a process for the preparation of a novel toner satisfying a high resolution, a low temperature fixability and a high offset resistance at a low cost. A novel toner for the development of an electrostatic image is provided comprising an agglomerate of particles containing at least primary polymer particles, wherein said primary polymer particles substantially comprise a wax encapsulated therein.

Abstract: The present invention provides a process for the preparation of a novel toner satisfying a high resolution, a low temperature fixability and a high offset resistance at a low cost. A novel toner for the development of an electrostatic image is provided comprising an agglomerate of particles containing at least primary polymer particles, wherein said primary polymer particles substantially comprise a wax encapsulated therein.

Abstract: A process for preparing an aromatic polycarbonate resin from an aromatic dihydroxy compound and a carbonate diester by transesterification in the presence of a transesterification catalyst comprising; reacting a purified carbonate diester with an aromatic dihydroxy compound in the presence of a transesterification catalyst to form a polycarbonate prepolymer; said carbonate diester containing benzophenone and benzoate ester derivatives having a molecular weight of less than 1,000, each in an amount of 100 ppm or less, said polycarbonate prepolymer having a viscosity average molecular weight of 5,000 to 20,000 at a temperature of 140.degree. to 280.degree. C., the reaction pressure being from 0.1 Torr to normal pressure; polymerizing said prepolymer at a temperature of 240.degree. to 350.degree. C. in a lateral, bi-axial, self-cleaning reactor to obtain an aromatic polycarbonate resin having a viscosity average molecular weight of 15,000 to 60,000.

Abstract: Disclosed herein is an aromatic polycarbonate resin containing benzophenone and benzoate ester derivatives which have a molecular weight less than 1,000, each in an amount of 100 ppm or less. Also disclosed is a process for preparing an aromatic polycarbonate resin from an aromatic dihydroxy compound and a carbonate diester in which the benzophenone derivative content is 100 ppm or less by transesterification, comprising preparing a polycarbonate prepolymer having a viscosity average molecular weight of 5,000 to 20,000 using an iminocarboxylic acid or salt thereof as a transesterification catalyst and polymerizing the prepolymer in an extruder.The aromatic polycarbonate is colorless and transparent and is suitable for extrusion molding.

Abstract: Disclosed herein are a coppolymerized polyester produced by copolymerizing a dicarboxylic acid component (A) comprising(a) 10 to 90 mol % of isophthalic acid or an ester forming derivative thereof,(b) 10 to 60 mol % of a phenylenedi(oxyacetic acid) represented by the formula [I]: ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atom, an alkoxy group having 1 to 6 carbon atom, a phenyl group, a chlorine atom, a bromine atom or a fluorine atom), or as ester forming derivative thereof, and(c) 0 to 45 mol % of a naphthalenedicarboxylic acid or an ester forming derivative thereof, anda diol component (B); and a polyester composition containing the copolymerized polyester.

Abstract: Disclosed herein are a copolymerized polyester produced by copolymerizing a dicarboxylic acid component (A) comprising(a) 10 to 90 mol % of isophthalic acid or an ester forming derivative thereof,(b) 10 to 60 mol % of a phenylenedi(oxyacetic acid) represented by the formula [I]: ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atom, an alkoxy group having 1 to 6 carbon atom, a phenyl group, a chlorine atom, a bromine atom or a fluorine atom), or an ester forming derivative thereof, and(c) 0 to 45 mol % of a naphthalenedicarboxylic acid or an ester forming derivative thereof, anda diol component (B); and a polyester composition containing the copolymerized polyester.