Patent ID: 8969445
Filing Date: 2015-03-03
Classification: C08K,C08L,F16L,Y10T

Abstract:
1. A pipe formed of a polyolefin composition consisting of a) a polyolefin base resin (A) consisting of a polyethylene homo- or copolymer, and a specific combination of two antioxidants consisting of (B) and (C): b) 150 to 500 ppm of an antioxidant (B) according to formula (I): wherein R 1 , R 2 , R 3 , R 4 and R 5 independently are H, or non-substituted or substituted aliphatic or aromatic hydrocarbyl radicals which may comprise heteroatoms, and c) 1600 to 5000 ppm of an antioxidant (C) according to formula (II): wherein R 6 , R 7 and R 8 independently are non-substituted or substituted aliphatic or aromatic hydrocarbyl radicals which may comprise OH-groups, X 1 , X 2 , and X 3 independently are H or OH, with the provisio that at least one of X 1 , X 2 , and X 3 is OH, the entire molecule does not comprise an ester group, and the concentration of antioxidants (B) and (C) in the polyolefin composition is based on the total composition, and wherein a failure time of said pipe exceeds 1165 hours when tested according to ASTM F2263-03, modified by replacing chlorine with chlorine dioxide.