Patent ID: 6914098

Claim:
A method of producing a butenedioic acid monoalkyl ester-copolymerized acrylic elastomer which contains 0.1-30% by mole of unresated butenedioic acid monoalkyl ester on the basic of carboxyl groups copolymerized in the acrylic elastomer, which method comprises: determining an amount of butenedioic acid monoalkyl ester copolymerized in a butenedioic acid monoalkyl ester-copolymerized acrylic elastomer; and adjusting the amount of unreacted butenedioic acid monoalkyl ester in the acrylic elastomer to 0.1-30% by mole on the basis of carboxyl groups copolymerized in the acrylic elastomer to improve compression set characteristics of cross-linking product of the acrylic elastomer.