Patent ID: 7053169

Claim:
Transparent thermoplastic polyamide molding materials based on copolyamides with a refractive index n D 20 above 1.59 with a primary proportion by weight of diamines and dicarboxylic acids with aromatic cores, characterized by the following chains, represented by Formula I: —{IPS—NH—R 1 —NH}n 1 -{TPS—NH—R 2 —NH}n 2 —{CO—R 3 —NH}n 3 - (I) where: n 1 =40 to 100 wt % n 2 =60 to 0 wt % n 3 =0 to 30 wt %, and where the proportions, in wt %, of n 1 , n 2 , and n 3 total 100%, whereby the diamines with the cores R 1 , R 2 can be identical or different, and at least 30 mol % diamines in relation to 100 mol % diamines consist of para-xylylene or meta-xylylene units and can consist of linear aliphatic or branched aliphatic chains with 2 to 12 (CH 2 ) units or chains with cycloaliphatic cores which can be incorporated individually or as blends, and whereby 100 mol % of the dicarboxylic acids consist of at least 40 mol % isophthalic acid (IPS) and, as a residue, terephthalic acid (TPS), which can be replaced partly or wholly by naphthalene dicarboxylic acids, whereby up to 30 wt % of the copolyamides of the molding compounds can be replaced by amino acids or lactams with core R 3 , consisting of chains with 5 to 11 (CH 2 ) units.