Curing system for polyacrylate rubbers

Claim 1

A curable composition comprising: (a) a curable polyacrylate rubber having halogen and carboxyl cure sites and comprising (i) from about 40 percent to about 99.8 percent by weight of an acrylate of the formula: CH.sub.2 ═CH--COOR wherein R is selected from the group consisting of an alkyl radical containing 1 to 8 carbon atoms, an alkoxyalkyl, an alkylthioalkyl, and a cyanoalkyl radical containing 2 to 12 carbon atoms; (ii) from about 0.1 percent to about 30 percent by weight of a halogen-containing monomer selected from the group consisting of halogen-containing vinylene hydrocarbons and halogen-containing vinyl monomers having the halogen group at least two carbon atoms removed from an oxygen group; (iii) from about 0.1 percent to about 20 percent by weight of a carboxyl-containing monomer; and (iv) 0 to 35 percent by weight of a copolymerizable monomer containing a terminal vinylidene group; and (b) an effective amount of a curing system comprising (i) as a curative, an alkali metal carboxylate salt of the formula C m H 2m+1 COOM wherein M is an alkali metal and m is 3 to 23; (ii) as an accelerator, a tertiary amine of the formula (CH 3 ) 2 NC n H 2n+1 wherein n is 4 to 24; and (iii) as a retarder, a disubstituted urea of the formula: ##STR5## wherein X is sulfur or oxygen, and R 1 and R 2 are independently selected from the group consisting of aliphatic and aromatic radicals containing 1 to 12 carbon atoms.