To obtain the subject copolymer excellent in transparency, heat resistance and light resistance by making the copolymer contain a unit derived from a specific aromatic vinyl-based compound and a unit derived from a specific polycyclic (meth)acrylate.
This copolymer contains (A) 5-99 mol.%, of a unit derived from an aromatic vinyl-based compound expressed by formula I (R1 is H, etc.; R2 to R6 are each independently H, C, O, etc.), and (B) 95-1 mol.% of a unit derived from a polycyclic (meth)acrylate expressed by formula II {(n) is 1-3; X1 is a lower alkylene, etc.; R10 is H, etc.; R11 to R27 are each H, C, O, etc.}. The copolymer has 2,000-500,000 weight-average molecular weight determined by gel permeation chromatography and 10-200°C glass transition point determined by a differential scanning calorimeter.
ISHIDA TATSUKAZU
MASUDA TORU
MYONAKA ATSUSHI
HONSHU CHEMICAL IND