Nitroxide compounds for minimizing scorch in crosslinkable compositions

Abstract

Scorch is inhibited during the free-radical crosslinking of a crosslinkable polymer, e.g., an EPDM, by incorporating into the polymer before melt processing and crosslinking a scorch inhibiting amount of a derivative, preferably an ether, ester or urethane derivative, of a TEMPO compound, e.g., 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl. The scorch inhibitors of this invention perform as well, if not better, than their 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl counterparts in similar polymer compositions and under similar conditions in terms of scorch inhibition and ultimate degree of crosslinking, but exhibit less volatility and less migration within the polymer composition.

Dependencies are inferred from the claim text.