Patent ID: 8211517

Claim:
A multi-layered co-extruded tube comprising A) an outer layer comprising a first polymer composition comprising a first semiaromatic semicrystalline polyamide and a copper thermal stabilizer, said first semiaromatic semicrystalline polyamide consisting essentially of a) at least one repeat unit derived from monomers selected from one or more of the group consisting of: (i) aromatic dicarboxylic acid having 8 to 20 carbon atoms and at least one aliphatic diamine having 6 to 12 carbon atoms, and a) at least one repeat unit derived from monomers selected from one or more of the group consisting of: (ii) aliphatic dicarboxylic acid having 10 to 14 carbon atoms and at least one aliphatic diamine having 6 to 12 carbon atoms, and (iii) lactam and/or aminocarboxylic acid having 6 to 20 carbon atoms; and B) an inner layer comprising a second polymer composition comprising a second semiaromatic semicrystalline polyamide; wherein said first semiaromatic semicrystalline polyamide has a melt temperature of about 240° C. to 280° C.; and said second semiaromatic semicrystalline polyamide has a glass transition temperature equal to or greater than 100° C. as measured with dynamic mechanical analysis using ISO-6721-3 method.