Acrylic rubber composition

An acrylic rubber composition comprising 5 to 15 parts by weight of a plasticizer having a solubility parameter SP value (by Small's method) of 8.5 to 10.5 based on 100 parts by weight of super cold resistant grade acrylic rubber having a glass transition point Tg of −42° C. or less, wherein the acrylic rubber composition provides a vulcanizate with a TR10 value, which is an index of cold resistance, of −42° C. or less both initially and after oil dipping;

• wherein the vulcanizate exhibits a volume change rate of +6% or more in a dipping test at 150° C. for 70 hours according to JIS K6258 corresponding to ISO 1817:1999, and
• wherein the super cold resistant grade acrylic rubber is a copolymer obtained by copolymerizing 1 to 3 wt. % of a vinyl monochloroacetate monomer as a crosslinkable comonomer in the copolymer, in which 67.35 to 75.51 wt. % of n-butyl acrylate and 32.65 to 24.49 wt. % of 2-methoxyethyl acrylate are charged in 100 wt. % of comonomers other than the crosslinkable comonomer and then copolymerized, and
• the copolymer consisting of n-butyl acrylate, 2 methoxyethyl acrylate and the crosslinkable comonomer.