Crosslinked rubber article and solid composition

Abstract

A cross-linked rubber article contains cross-linked rubber comprising a structural unit primarily composed of tetrafluoroethylene. In the aforementioned cross-linked rubber article, the total content of compound (B) is less than 10,000 ppb by mass, the content of compound (S1) is less than 1,000 ppb by mass, and the content of compound (S11) is less than 1,000 ppm by mass. Compound (B) is a compound having CF2 groups and ionic functional groups, lacking carbon-carbon double bonds and carbon-carbon triple bonds, and having a number average molecular weight of less than 3,000. The number of CF2 groups relative to each ionic functional group is less than 30; M1 is a hydrogen atom, Na, K, or NH4; X111 and X112 are hydrogen atoms, fluorine atoms, chlorine atoms, or fluorinated alkyl groups having 1 to 20 carbon atoms; p1 is an integer from 3 to 13; q11 and r11 are integers greater than or equal to 0. H(CF2)p1COOM1 (S1) CF3(OCFX111)q11(OCFX112)r11OCF3 (S11)