| abstract |
A copolymer having a polystyrene reduced number average molecular weight of 10 3 -10 8 , and comprising repeating units of formulas (1), (2), and (3), nwherein R 1 and R 2 independently represent a hydrogen atom, alkyl group, etc.; R 3 and R 4 independently represent alkyl group, etc.; and m and n independently represent an integer of 0-3, nwherein R 5 and R 6 independently represent a hydrogen atom, alkyl group, etc.; either R 5 or R 6 is different from either R 1 or R 2 ; R 7 and R 8 independently represent an alkyl group, etc.; and k and l are independently an integer of 0-3, n-Ar 1 -(3) nwherein Ar 1 represents an arylene group, etc. The copolymer has an excellent solubility in an organic solvent, and a high glass transition temperature in good balance, an a polymer LED of high performance, such as low-voltage driving and high luminance, is provided. |