Fluororubber composition

A fluororubber composition comprising:

• a fluororubber (A);
• a carbon black (B);
• an aromatic petroleum resin (E);
• and
• a crosslinking agent (C),
• the fluororubber composition has a difference δG′ (G′(1%)-G′(100%)) of not lower than 150 kPa and not higher than 863 kPa, where G′(1%) denotes a shear modulus at a dynamic strain of 1%, G′(100%) denotes a shear modulus 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.,
• wherein the aromatic petroleum resin (E) is a coumarone-indene-styrene resin,
• wherein the carbon black (B) has a nitrogen adsorption specific surface area (N2SA) of 25 to 180 m2/g and a dibutyl phthalate (DBP) absorption number of 40 to 175 ml/100 g,
• wherein the carbon black (B) is at least one selected from the group consisting of ISAF and HAF,
• wherein the fluororubber composition contains 8 to 20 parts by mass of the carbon black (B) relative to 100 parts by mass of the fluororubber (A),
• wherein the amount of the aromatic petroleum resin (E) is 0.01 to 2 parts by mass relative to 100 parts by mass of the fluororubber (A),
• wherein the fluororubber (A) consists of a vinylidene fluoride/hexafluoropropylene binary copolymer in which the vinylidene fluoride unit/the hexafluoropropylene unit (molar ratio) is 78/22,
• wherein the crosslinking agent (C) is an organic peroxide, and
• wherein the blending quantity of the crosslinking agent (C) is 0.1 to 8 parts by mass relative to 100 parts by mass of the fluororubber (A).