Abstract: The problem to be solved by the present invention is to provide a polycarbonate copolymer containing a plant-derived raw material, which is excellent in the mechanical strength and heat-resistant and assured of small refractive index, large Abbe number, small birefringence and excellent transparency. The present invention provides a polycarbonate copolymer containing a constitutional unit derived from a dihydroxy compound represented by the following formula (1) and a constitutional unit derived from an alicyclic dihydroxy compound, wherein the Abbe number is 50 or more and the 5% thermal reduction temperature is 340° C. or more; and a method of producing this polycarbonate copolymer by reacting a dihydroxy compound represented by the following formula (1) and an alicyclic hydroxy compound with a carbonic acid diester in the presence of a polymerization catalyst.

Abstract: The problem to be solved by the present invention is to provide a polycarbonate copolymer containing a plant-derived raw material, which is excellent in the mechanical strength and heat-resistant and assured of small refractive index, large Abbe number, small birefringence and excellent transparency. The present invention provides a polycarbonate copolymer containing a constitutional unit derived from a dihydroxy compound represented by the following formula (1) and a constitutional unit derived from an alicyclic dihydroxy compound, wherein the Abbe number is 50 or more and the 5% thermal reduction temperature is 340° C. or more; and a method of producing this polycarbonate copolymer by reacting a dihydroxy compound represented by the following formula (1) and an alicyclic hydroxy compound with a carbonic acid diester in the presence of a polymerization catalyst.

Abstract: The problem to be solved by the present invention is to provide a polycarbonate copolymer containing a plant-derived raw material, which is excellent in the mechanical strength and heat-resistant and assured of small refractive index, large Abbe number, small birefringence and excellent transparency. The present invention provides a polycarbonate copolymer containing a constitutional unit derived from a dihydroxy compound represented by the following formula (1) and a constitutional unit derived from an alicyclic dihydroxy compound, wherein the Abbe number is 50 or more and the 5% thermal reduction temperature is 340° C. or more; and a method of producing this polycarbonate copolymer by reacting a dihydroxy compound represented by the following formula (1) and an alicyclic hydroxy compound with a carbonic acid diester in the presence of a polymerization catalyst.

Abstract: A subject for the invention relates to processes for producing a polycarbonate containing a plant-derived starting material and to molded articles thereof, the polycarbonate having excellent mechanical strength, heat resistance, a low refractive index, a large Abbe number, low birefringence, and excellent transparency. The invention relates to a process for producing a polycarbonate which includes a step in which one or more dihydroxy compounds including a dihydroxy compound having at least one linking group —CH2—O— in the molecule thereof are reacted with a carbonic acid diester in the presence of a polymerization catalyst, wherein the dihydroxy compound having at least one linking group —CH2—O— in the molecule thereof has a formic acid content lower than 20 ppm.

Abstract: The problem to be solved by the present invention is to provide a polycarbonate copolymer containing a plant-derived raw material, which is excellent in the mechanical strength and heat-resistant and assured of small refractive index, large Abbe number, small birefringence and excellent transparency. The present invention provides a polycarbonate copolymer containing a constitutional unit derived from a dihydroxy compound represented by the following formula (1) and a constitutional unit derived from an alicyclic dihydroxy compound, wherein the Abbe number is 50 or more and the 5% thermal reduction temperature is 340° C. or more; and a method of producing this polycarbonate copolymer by reacting a dihydroxy compound represented by the following formula (1) and an alicyclic hydroxy compound with a carbonic acid diester in the presence of a polymerization catalyst.

Abstract: A subject for the invention relates to processes for producing a polycarbonate containing a plant-derived starting material and to molded articles thereof, the polycarbonate having excellent mechanical strength, heat resistance, a low refractive index, a large Abbe number, low birefringence, and excellent transparency. The invention relates to a process for producing a polycarbonate which includes a step in which one or more dihydroxy compounds including a dihydroxy compound having at least one linking group —CH2—O— in the molecule thereof are reacted with a carbonic acid diester in the presence of a polymerization catalyst, wherein the dihydroxy compound having at least one linking group —CH2—O— in the molecule thereof has a formic acid content lower than 20 ppm.

Abstract: The object is to provide a polycarbonate copolymer having excellent mechanical strength, good heat resistance, a low refractive index, a large Abbe number, a low berefringence and excellent transparency and containing a plant-derived raw material. Disclosed is a polycarbonate copolymer which comprises a constituent unit derived from a dihydroxy compound represented by the general formula (1) and a constituent unit derived from an alicyclic dihydroxy compound and has an Abbe number of 50 or greater and “a 5% heating weight loss temperature” (a temperature at which the 5% weight loss under heating is observed) of 340° C. or higher. Also disclosed is a process for producing the polycarbonate copolymer by reacting a dihydroxy compound represented by the general formula (1) and an alicyclic dihydroxy compound with a carbonate diester in the presence of a polymerization catalyst.

Abstract: To provide a polyester resin having 1,4-CHDA as the main dicarboxylic acid units, having isomerization of trans-1,4-CHDA suppressed in the esterification and polyconsensation reactions and having a high melting point and excellent heat resistance, and a process for its production. A polyester resin obtainable by preparing an oligomer by an esterification reaction of a dicarboxylic acid component containing 1,4-cyclohexane dicarboxylic acid as the main component, with a diol component, and polycondensing this oligomer in the presence of a polycondensation catalyst; and a process for producing a polyester resin characterized in that the esterification reaction is carried out by means of a basic compound, and then, the polycondensation reaction is carried out by means of a polycondensation catalyst.