Acrylic rubber (ACM) is a synthetic rubber primarily composed of acrylic acid esters, characterized by particularly excellent heat resistance, oil resistance, and weather resistance. It is strong against mineral oils, ATFs, and ozone degradation, making it suitable for use in high-temperature environments. Its main applications include sealing materials and vibration dampeners such as O-rings, gaskets, oil seals, and hoses in automotive engines. After kneading, it is molded by methods such as compression molding, injection molding, and extrusion, and its final physical properties are developed through vulcanization. While its low-temperature properties tend to be inferior to NBR, it is widely adopted for parts requiring reliability in high-temperature and oily environments.