| 摘要 |
PROBLEM TO BE SOLVED: To obtain a molding polyamide composition having a high refractive index, a high Abbe's number and a relatively low density and applicability to optics by using at least one homopolyamide obtained from a long-chain aliphatic monomer block having an alicyclic monomer block. SOLUTION: This composition comprises a homopolyamide substantially consisting of a 14-22C alkyl-substituted alicyclic amide at most 50mol% of which may be replaced by an aromatic dicarboxylic acid and an 8-14C non- branched aliphatic dicarboxylic acid or of an 8-14C non-branched aliphatic diamine at most 50mol% of which may be replaced by an aromatic dicarboxylic acid and a 7-36C alicyclic dicarboxylic acid. This composition can be molded into an optical lens having a density of 1.1g/cm<3> or below, a refractive index nD<20> of 1.50 or above and an Abbe's number of 40 or above. |
