| abstract |
An object of the present invention is to obtain a polycarbodiimide having a higher refractive index than usual, having excellent thermal stability, high processability and moldability. SOLUTION: The following formula (1): Embedded image (In the formula, R 1 represents a naphthylene group.) M repeating units represented by the following formula (2): Embedded image (In the formula, R 2 means an organic diisocyanate residue other than R 1. ) A polycarbodiimide copolymer having n repeating structural units represented by and having terminal structural units derived from monoisocyanate at both terminals, wherein m + n is 3 to 200, and n / ( m + n) is a 0.05 to 0.99 polycarbodiimide copolymer. [Selection diagram] None |