1,4-Butanediol, 2,3-bis((gamma-omega-perfluoro-C6-20-alkyl)thio) derivs. 2,3-Bis(1,1,2,2-tetrahydroperfluoroalkyl(C6-C20)thio)butane-1,4-diol 68187-24-6 EINECS 269-080-4