Pipe made of peroxide-crosslinked polyethylene of high UV stability

A pipe comprising

• a peroxide-crosslinked polyethylene, wherein the peroxide-crosslinked polyethylene is obtained from a crosslinkable polyethylene by a crosslinking treatment with a peroxide in the absence of any non-peroxide crosslinking agent,
• wherein the crosslinkable polyethylene is an ethylene homopolymer or an ethylene copolymer with comonomer units derived from a C3-8 alpha-olefin and/or a non-conjugated diene,
• 0.1 to 0.3 wt % of pentaerythritol tetrakis-3-(3′,5′-di-tert-butyl-4-hydroxyphenyl) propionate (CAS number 6683-19-8), 0.08 to 0.35 wt % octadecyl-3-(3′,5′-di-tert-butyl-4-hydroxyphenyl) propionate (CAS No. 2082-79-3), and 0.25 to 0.65 wt % of 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxy benzyl) benzene (CAS number 1709-70-2), and
• a sterically hindered amine which comprises the following repeating unit of formula (I):
• wherein x is 4-8, R1 and R2, independently from each other, are H or methyl;
• and
• R3 and R4, independently from each other, are H, a C2-12 alkyl group, a C5-7 cycloalkyl group, or a saturated nitrogen-containing heterocyclic group;
• or R3 and R4, together with the nitrogen atom to which they are attached, form a 5- to 7-membered saturated heterocyclic ring.