| abstract |
Provided is a fluororubber composition having excellent tensile properties at high temperatures. The fluororubber composition comprises a fluororubber (A) and a carbon black (B), and the fluororubber (A) is a vinylidene fluoride-based fluororubber comprising a structural unit (VdF unit) derived from vinylidene fluoride and a structural unit derived from at least one monomer selected from the group consisting of hexafluoropropylene (HFP), 2,3,3,3-tetrafluoro propylene, and perfluoro(alkyl vinyl ether) (PAVE), and the molar ratio of the VdF unit to the structural unit derived from at least one monomer selected from the group consisting of HFP, 2,3,3,3-tetrafluoro propylene, and PAVE is 50/50 to 78/22, wherein the fluororubber composition a difference δG' (G'(1%) - G'(100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G'(1%) denotes a modulus of shearing elasticity at a dynamic strain of 1%, G'(100%) denotes a modulus of shearing elasticity at a dynamic strain of 100%, and G'(1%) and G'(100%) are determined by a dynamic viscoelasticity test carried out on an unvulcanised rubber with a rubber process analyzer (RPA)in a condition that the measurement frequency is 1 Hz and the measurement temperature is 100°C. |