Abstract: A copolymerized polyester resin containing a unit (A) represented by the following formula (1), a diol unit (B), and a unit (C) derived from a dicarboxylic acid or an ester-forming derivative of the dicarboxylic acid, wherein a content of the unit (A) based on total units of the copolymerized polyester resin is 10 to 95 mol %, and the copolymerized polyester resin satisfies the following conditions (1) to (3): (1) a glass transition temperature of the copolymerized polyester resin is 90° C. or higher; (2) an amount of heat generated by the copolymerized polyester resin at cooling crystallization is 5 J/g or less; and (3) an absolute value of photoelastic coefficient of the copolymerized polyester resin is 40×10?12 Pa?1 or less: wherein R1 is a hydrogen atom, CH3, or C2H5, R2 and R3 are each independently a hydrogen atom or CH3, and n is 0 or 1.

Abstract: A polyester resin having a diol constitutional unit and a dicarboxylic acid constitutional unit, wherein 20 to 100 mol % of the diol constitutional unit is a constitutional unit derived from a diol having a dinorbornane ring; a glass transition temperature of the polyester resin is 90° C. or higher; an amount of heat of a crystallization exothermic peak in temperature drop of the polyester resin is 5 J/g or less; and a yellow index (YI) value as measured by a reflection method according to JIS K 7103 is 10 or less.

Abstract: A copolymerized polyester resin containing a unit (A) represented by the following formula (1), a diol unit (B), and a unit (C) derived from a dicarboxylic acid or an ester-forming derivative of the dicarboxylic acid, wherein a content of the unit (A) based on total units of the copolymerized polyester resin is 10 to 95 mol %, and the copolymerized polyester resin satisfies the following conditions (1) to (3): (1) a glass transition temperature of the copolymerized polyester resin is 90° C. or higher; (2) an amount of heat generated by the copolymerized polyester resin at cooling crystallization is 5 J/g or less; and (3) an absolute value of photoelastic coefficient of the copolymerized polyester resin is 40×10?12 Pa?1 or less: wherein R1 is a hydrogen atom, CH3, or C2H5, R2 and R3 are each independently a hydrogen atom or CH3, and n is 0 or 1.

Abstract: The present invention addresses the problem of providing a resin having a high Abbe number and a small difference in hygroscopic expansion coefficient with respect to a polycarbonate resin having a low Abbe number and a high refractive index. The above problem can be solved by a polycarbonate resin including structural units represented by general formula (1). In general formula (1), R represents H, CH3, or C2H5.

Abstract: A process for producing a polycarbonate resin by reacting raw materials of a bifunctional compound and diphenyl carbonate, where the bifunctional compound is an isomer mixture of: a 2,6-derivative of a bifunctional compound of formula (3-a): and a 2,7-derivative of a bifunctional compound of formula (3-b): where R2 in formulae (3-a) and (3-b) is, independently, H, CH3 or C2H5, and where the mixing ratio between the 2,6-derivative and the 2,7-derivative is 30:70 to 70:30.

Abstract: The present invention is able to provide a bifunctional compound represented by formula (1). (In the formula, R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO; and R2 represents H, CH3 or C2H5.

Abstract: A method for producing a bifunctional compound of formula (3) wherein R2 represents H, CH3 or C2H5, the method comprising reducing a bifunctional compound of formula (1): wherein R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9, or CHO; and R2 represents H, CH3 or C2H5, provided that when R1 represents CHO, R2 represents C2H5, in the presence of a catalyst having hydrogenation activity and hydrogen.

Abstract: A polyester resin according to the present invention comprises a constitutional unit represented by general formula (1): wherein R1 is a hydrogen atom, CH3, or C2H5; and R2 and R3 are each independently a hydrogen atom or CH3.

Abstract: The present invention is able to provide a bifunctional compound represented by formula (I). (In the formula, R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO; and R2 represents H, CH3 or C2H5.

Abstract: The bifunctional compound according to the present invention is represented by the following formula (1): wherein R1 is a hydrogen atom, CH3, or C2H5; R2 and R3 are each independently a hydrogen atom or CH3; and X is a hydrogen atom or a hydrocarbon group having no more than 4 carbon atoms and optionally containing a hydroxyl group.

Abstract: The present invention addresses the problem of providing a resin having a high Abbe number and a small difference in hygroscopic expansion coefficient with respect to a polycarbonate resin having a low Abbe number and a high refractive index. The above problem can be solved by a polycarbonate resin including structural units represented by general formula (1). In general formula (1), R represents H, CH3, or C2H5.

Abstract: The present invention is able to provide a bifunctional compound represented by formula (1). (In the formula, R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO; and R2 represents H, CH3 or C2H5.

Abstract: A polyester resin mainly having a diol constitutional unit and a dicarboxylic acid constitutional unit, wherein 20 to 100 mol % of the diol constitutional unit is a constitutional unit derived from a diol having a dinorbornane ring represented by the following formula (i); a glass transition temperature is 90° C. or higher; an amount of heat of a crystallization exothermic peak in temperature drop is 5 J/g or less; and an YI value as measured by a reflection method according to JIS K 7103 is 10 or less: wherein R is H, CH3, or C2H5.

Abstract: The present invention is able to provide a bifunctional compound represented by formula (1). (In the formula, R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO; and R2 represents H, CH3 or C2H5.

Abstract: The present invention addresses the problem of providing a resin having a high Abbe number and a small difference in hygroscopic expansion coefficient with respect to a polycarbonate resin having a low Abbe number and a high refractive index. The above problem can be solved by a polycarbonate resin including structural units represented by general formula (1). In general formula (1), R represents H, CH3, or C2H5.

Abstract: A polyester resin according to the present invention comprises a constitutional unit represented by general formula (1): wherein R1 is a hydrogen atom, CH3, or C2H5; and R2 and R3 are each independently a hydrogen atom or CH3.

Abstract: A method for producing a bifunctional compound of formula (1): where R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO and R2 represents H, CH3 or C2H5, by subjecting a monoolefin of formula (2): where R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO and R2 represents H, CH3 or C2H5, carbon monoxide and hydrogen gases to a hydroformylation reaction in the presence of a rhodium compound and an organic phosphorous compound. Compounds produced.

Abstract: The bifunctional compound according to the present invention is represented by the following formula (1): wherein R1 is a hydrogen atom, CH3, or C2H5; R2 and R3 are each independently a hydrogen atom or CH3; and X is a hydrogen atom or a hydrocarbon group having no more than 4 carbon atoms and optionally containing a hydroxyl group.

Abstract: The present invention addresses the problem of providing a resin having a high Abbe number and a small difference in hygroscopic expansion coefficient with respect to a polycarbonate resin having a low Abbe number and a high refractive index. The above problem can be solved by a polycarbonate resin including structural units represented by general formula (1). In general formula (1), R represents H, CH3, or C2H5.

Abstract: The present invention is able to provide a bifunctional compound represented by formula (1). (In the formula, R1 represents COOCH3, COOC2H5, COOC3H7, COOC4H9 or CHO; and R2 represents H, CH3 or C2H5.