Abstract: A heat-resistant seal material includes 100 parts by weight of a ternary fluoroelastomer, 1 to 30 parts by weight of vapor-grown carbon fibers having an average diameter of more than 30 nm and 200 nm or less, and carbon black having an average particle diameter of 25 to 500 nm. The heat-resistant seal material contains the vapor-grown carbon fibers and the carbon black in an amount of 20 to 40 parts by weight in total. The heat-resistant seal material has a compression set when subjected to a compression set test at a compression rate of 25% and a temperature of 200° C. for 70 hours of 0 to 15% and a dynamic modulus of elasticity at 200° C. (E?/200° C.) of 30 to 100 MPa.

Abstract: A heat-resistant seal material includes 100 parts by weight of a ternary fluoroelastomer, 1 to 30 parts by weight of vapor-grown carbon fibers having an average diameter of more than 30 nm and 200 nm or less, and carbon black having an average particle diameter of 25 to 500 nm. The heat-resistant seal material contains the vapor-grown carbon fibers and the carbon black in an amount of 20 to 40 parts by weight in total. The heat-resistant seal material has a compression set when subjected to a compression set test at a compression rate of 25% and a temperature of 200° C. for 70 hours of 0 to 15% and a dynamic modulus of elasticity at 200° C. (E?/200° C.) of 30 to 100 MPa.

Abstract: A piston seal of a disc brake can stabilize the amount of rollback of a piston by reducing thermal expansion and a decrease in modulus of elasticity of the piston seal caused by an increase in temperature, thereby preventing a driver from feeling that the brake operation is unnatural. The piston seal is formed of a rubber composition in which at least 100 parts by weight or more of carbon black is added to 100 parts by weight of ethylene propylene rubber.

Abstract: A piston seal of a disc brake can stabilize the amount of rollback of a piston by reducing thermal expansion and a decrease in modulus of elasticity of the piston seal caused by an increase in temperature, thereby preventing a driver from feeling that the brake operation is unnatural. The piston seal is formed of a rubber composition in which at least 100 parts by weight or more of carbon black is added to 100 parts by weight of ethylene propylene rubber.

Abstract: A piston seal of a disc brake can stabilize the amount of rollback of a piston by reducing thermal expansion and a decrease in modulus of elasticity of the piston seal caused by an increase in temperature, thereby preventing a driver from feeling that the brake operation is unnatural. The piston seal is formed of a rubber composition in which at least 100 parts by weight or more of carbon black is added to 100 parts by weight of ethylene propylene rubber.