PURPOSE: To obtain the titled blend capable of giving cured products with extremely outstanding compression set, by incorporating a halogen-contg. acrylic rubber with, as the curing system, a combination of trithiocyanuric acid, trimethyl thiourea and metal oxide.

CONSTITUTION: The objective blend can be obtained by incorporating (A) 100pts. wt. of a halogen-contg. acrylic rubber prepared by copolymerization between (i) 60W99.9wt.% of an alkyl acrylate monomer, (ii) 10W0.1wt.% of a halogen- contg. monomer (e.g., 2-chloroethyl vinyl ether) and (iii) 30W0wt.% of a copolymerizable monomer (e.g., acrylic acid, vinyl acetate) with (B) 0.1W10(pref. 0.3W2)pts.wt. of trithiocyanuric acid, (C) 0.1W10(pref. 0.2W2pts.wt. of trimethyl thiourea, (D) 0.1W10(pref. 0.2W2)pts.wt. of a metal oxide (e.g., zinc oxide sodium oxide) and (E) other ingredient(s).