HEXAFLUOROBUTADIENE PURIFICATION METHOD Russian patent published in 2005 - IPC

FIELD: industrial organic synthesis.

SUBSTANCE: hexafluorobuta-1,3-diene, suitable as bifunctional monomer in production and cross-linking of perfluorinated elastomers but also as agent for dry plasma etching in manufacture of semiconductor articles, is first subjected to low-temperature rectification and then additionally purified on zeolite sorbents and submitted to vacuum degassing and filtration. Low-temperature rectification is carried out in two steps: first at overpressure in column from 1.0 atm to 0.05 atm and still temperature 15-25^оС, and then, respectively, 0.3 to 0.2 atm and 15-25^оС. After first or second low-temperature rectification step product additionally undergoes cleaning on carbon sorbents.

EFFECT: simplified process technology.

5 cl, 2 tbl, 5 ex