Crosslinkable electrically conductive eva copolymer compsns. - contain carbon and a 4-hydroxy-3,5-di:tert. butyl-phenyl propionic acid deriv. as anti-ageing stabiliser

摘要

Compsn. (I) comprise (A) 50-80% (all pts. wt.) copolymer (II) with vinyl acetate content 5-20% and melt index 0.8-8.0 g/10 minutes (B) 10-50% C black (C) 1.0-2.5% crosslinking agent (D) 0.05-1.5% 4-hydroxy-3,5-di-tert.butylphenylpropionic acid deriv. (III). (II) has melt flow index 1-3 g/10 minutes. (I) contains 0.1-1.0% (III). (III) is octadecyl-4-hydroxy-3,5-di-tert.butylphenylpropionate (IV) and/or bis(4-hydroxy-3,5-di-tert.butylphenylpropionic acid) hydrazide (V) (mixt. of (IV) and (V) has synergistic effect). USE/ADVANTAGE - For use in conductor-smoothing and field limitation layers in medium and high tension cables. (III) do not react with crosslinking agent (peroxide) for (II), unlike sec. aromatic amines, so remain effective in stabilising (I) during processing and also do not give rise to inhomogeneous prods. which form specks and impair propert