Patent ID: 6889719

Claim:
A multi-layer plastic pipe for liquid containing antifreeze solution, the multi-layer plastic pipe comprising: an inner layer made of a first resin material, the first resin material having a PPS resin selected from a group of a polyphenylene sulfide and a denatured aromatic polysulfide resin; an intermediate layer made of a second resin material, the second resin material being a mixture of the PPS resin and a polyamide resin; and an outer layer made of a third resin material including a polyamide resin, wherein: the inner layer is formed such that permeation of the antifreeze solution having mainly ethylene glycol becomes less than 3.0 g/m 2 per day; the first resin material contains 20 to 40 wt % of a softening material including ethylene-gylcidyl methacrylate and ethylene-propylene copolymers; and the second resin material contains 10 to 30 wt % of a softening material including ethylene-gylcidyl methacrylate and ethylene-propylene copolymers.