Unimatec Co., Ltd

Daichi Toge

Daiki Watanabe

Iwao Moriyama

An acrylic rubber that is a copolymer in which 1 to 3 wt. % of a fumaric acid monoalkyl ester monomer containing an alkyl group having 1 to 8 carbon atoms is copolymerized as a crosslinkable comonomer, wherein 45 to 65 wt. % of n-butyl acrylate, 12 to 32 wt. % of 2-methoxyethyl acrylate, and 11 to 30 wt. % of ethoxyethoxyethyl acrylate are copolymerized in 100 wt. % of comonomers other than the crosslinkable comonomer. This acrylic rubber can suppress the reduction of oil resistance while improving cold resistance represented by a TR-10 value.

Acrylic rubber and crosslinkable composition thereof

An acrylic rubber that is a copolymer in which 1 to 4 wt. % of a reactive halogen group-containing vinyl monomer is copolymerized as a crosslinkable comonomer, wherein 45 to 65 wt. % of n-butyl acrylate, 10 to 35 wt. % of 2-methoxyethyl acrylate and 8 to 30 wt. % of ethoxyethoxyethyl acrylate are copolymerized in 100 wt. % of comonomers other than the crosslinkable comonomer. This ethoxyethoxyethyl acrylate-copolymerized acrylic rubber can suppress the reduction of oil resistance while improving cold resistance represented by a TR-10 value, and by compounding it with a vulcanizing agent corresponding to the crosslinkable group thereof, a crosslinkable composition is formed.

An acrylic rubber contains a copolymer of a monomer mixture of: 25 to 46 wt. % of alkoxyalkyl acrylate, 23 to 37 wt. % of 2-ethylhexyl acrylate, 9 to 17 wt. % of alkyl methacrylate, 1 to 3 wt. % of monoalkyl fumarate and the remaining amount is ethyl acrylate. This acrylic rubber improves hydrolysis resistance by introducing a specific alkyl acrylic monomer with extremely low hydrolysis property i.e. low hydrophilicity, and at the same time satisfies all of oil resistance, cold resistance, and hydrolysis resistance in a well-balanced manner.

Growing community of inventors

Ibaraki, Japan

Daichi Toge