Fluororubber composition and method for producing same

A fluororubber composition comprising:

• a fluororubber (A);
• and carbon black (B), wherein
• when the fluororubber composition is immersed for 160 hours in an extraction solvent of acetone and hexane at an acetone:hexane mass ratio of 42.29:57.71 at 40° C. and extraction residue that is not extracted and remains as a solid is separated from the aforementioned extraction solvent and dried and then the dry weight of the extraction residue is measured, the quantity of a solvent-insoluble polymer, as calculated using the expression below, is not lower than 5%:
• Quantity
• 
• 
• of
• 
• 
• solvent
• 
• -
• 
• insoluble
• 
• 
• polymer
• 
• 
• (
• %
• )
• =
• w
• ′
• ×
• Φ
• p
• ′
• w
• ×
• Φ
• p
• ×
• 100
• [
• Expression
• 
• 
• 1
• ]
• (where, w is an initial weight (g) of the fluororubber composition which is immersed in the extraction solvent, w′ is a dry weight (g) of the extraction residue, φp is an initial weight fraction of the fluororubber (A) contained in the fluororubber composition which is immersed in the extraction solvent relative to the fluororubber composition, and φp′ is a weight fraction of the fluororubber (A) contained in the extraction residue relative to the extraction residue.)