초록

Acrylate rubbers having both halogen and carboxyl cure sites are vulcanized using an alkali metal salt of a carboxylic or organo-phosphoric acid and an amine-blocked isocyanate. The vulcanized compositions exhibit low press-cured and post-cured compression set.

대표청구항 ▼

A composition comprising (1) an acrylate rubber comprising (a) from about 40 percent to about 99.8 percent by weight of an acrylate or mixtures of acrylates of the formula O �2=CHCO－R′ wherein R′is selected from the group consisting of an alkyl radical containing 1 to 18 carbon atoms, an alkoxyalkyl

A composition comprising (1) an acrylate rubber comprising (a) from about 40 percent to about 99.8 percent by weight of an acrylate or mixtures of acrylates of the formula O �2=CHCO－R′ wherein R′is selected from the group consisting of an alkyl radical containing 1 to 18 carbon atoms, an alkoxyalkyl radical, alkylthioalkyl radical, and cyanoalkyl radical each containing a total of 2 to about 12 carbon atoms in the radical, (b) from about 0.1 percent to about 30 percent by weight of a halogen-containing monomer selected from the group consisting of halogen-containing vinylidene hydrocarbons and halogen-containing vinyl monomers wherein the halogen group is at least 2 carbon atoms removed from an oxygen atom, (c) from about 0.1 percent to about 20 percent by weight of a carboxyl-containing monomer, and (d) up to about 35 percent by weight of a non-halogen-containing and non-carboxyl-containing copolymerizable monomer having a terminal vinylidene group, and (2) a cure system consisting essentially of (a) from about 0.5 part to about 7 parts by weight based upon 100 parts by weight of the rubber of an alkali metal salt of an acid selected from the group consisting of carboxylic acids containing 2 to about 24 carbon atoms and organophosphoric acids of the structure [Figure] wherein M is an alkali metal, y =1 or 2, z =1 or 2, and y +z =3, and R is selected from the group consisting of an alkyl radical containing 1 to 24 carbon atoms, an aryl radical containing 6 to 24 carbon atoms, and an alkylphenoxy poly(ethyleneoxy)ethyl radical, and (b) from about 0.1 part to about 10 parts by weight based upon 100 parts by weight of the rubber of an amine-blocked isocyanate wherein the amine has a dissociation constant of below 10 and is a secondary amine or guanidine.