Provided are a tricyclodecane dimethanol composition which may be usefully applied to the preparation of a high heat resistant polyester by reducing the content of impurities, and a preparation method thereof.

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): ##STR00001## and a 2,7-derivative of a bifunctional compound of formula (3-b): ##STR00002## where R.sub.2 in formulae (3-a) and (3-b) is, independently, H, CH.sub.3 or C.sub.2H.sub.5, and where the mixing ratio between the 2,6-derivative and the 2,7-derivative is 30:70 to 70:30.

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): ##STR00001## and a 2,7-derivative of a bifunctional compound of formula (3-b): ##STR00002## where R.sub.2 in formulae (3-a) and (3-b) is, independently, H, CH.sub.3 or C.sub.2H.sub.5, and where the mixing ratio between the 2,6-derivative and the 2,7-derivative is 30:70 to 70:30.

Provided are a tricyclodecane dimethanol composition which may be suitably used in preparing a polyester resin exhibiting excellent solvent resistance and chemical resistance when forming a coating film and having excellent solubility in organic solvents or water, and a preparation method thereof.

Provided are a tricyclodecane dimethanol composition which may be suitably used in preparing a polyester resin exhibiting excellent solvent resistance and chemical resistance when forming a coating film and having excellent solubility in organic solvents or water, and a preparation method thereof.

Provided are a tricyclodecane dimethanol composition, in which a ratio of structural isomers is controlled, and a preparation method thereof.

Provided are a tricyclodecane dimethanol composition, in which a ratio of structural isomers is controlled, and a preparation method thereof.

The present invention is able to provide a bifunctional compound represented by formula (1).

##STR00001##

(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

The present invention is able to provide a bifunctional compound represented by formula (1).

##STR00001##

(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

A method for producing a bifunctional compound of formula (3) ##STR00001## wherein R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, the method comprising reducing a bifunctional compound of formula (1): ##STR00002## wherein R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9, or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, provided that when R.sub.1 represents CHO, R.sub.2 represents C.sub.2H.sub.5, in the presence of a catalyst having hydrogenation activity and hydrogen.