Patent ID: 8067075

Claim:
A multilayer tube comprising at least three layers including: a layer (a) comprising (A) polyamide 11 and/or polyamide 12, a layer (b) consisting of (B) a semi-aromatic polyamide or a combination of a semi-aromatic polyamide and an additive selected from the group consisting of an antioxidant, a heat stabilizer, an ultraviolet absorbent, a light stabilizer, a lubricant, an inorganic filler, an antistatic agent, a flame retardant, a crystallization accelerator, a plasticizer, a colorant, a lubricating agent and an impact resistance improver, said semi-aromatic polyamide (B) consisting of a dicarboxylic acid unit containing a terephthalic acid and/or naphthalenedicarboxylic acid unit in a proportion of about 50 mol % or more based on all dicarboxylic acid units, and a diamine unit containing a 1,9-nonane-diamine and/or 2-methyl-1,8-octanediamine unit in a proportion of about 60 mol % or more based on all diamine units and a layer (c) comprising (C) a fluorine-containing polymer having introduced into the molecular chain thereof at least one functional group selected from the group consisting of a carboxy group, an acid anhydride group, a carboxylate group, an alkoxycarbonyl group, a hydroxyl group, a sulfo group, a sulfonate group, an epoxy group, a cyano group, a carbonate group and a carboxylic acid halide group, as said functional group having reactivity with the polyamide-based resin, and wherein said layer (b) comprising (B) the semi-aromatic polyamide is disposed between said layer (a) comprising (A) polyamide 11 and/or polyamide 12 and said layer (c) comprising (C) a fluorine-containing polymer.