Polymerization inhibitor for tetrafluoroethylene

Abstract

The invention provides a polymerization inhibitor preventing the self-polymerization of TFE and not modified to macromolecule body by oxygen in a distillation step, particularly in a rectification step, of TFE. The invention provides a method of distilling tetrafluoroethylene in the presence of the polymerization inhibitor comprising a cyclohexadiene compound of the formula: R<1>-A-R<2>, wherein R<1> is a hydrocarbon group having 1 to 5 carbon atoms, R<2> is a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and A is a cyclohexadiene ring. The cyclohexadiene compound is preferably alpha-terpinene or gamma-terpinene.

Description

technical field [0001] The present invention relates to a method for preventing clogging caused by self-polymerization of tetrafluoroethylene and a polymer modified product of a polymerization inhibitor in a distillation process of tetrafluoroethylene, particularly in a rectification process. Background technique [0002] In general, it is known that high-purity tetrafluoroethylene (hereinafter referred to as "TFE") is extremely easy to polymerize, and especially when a trace amount of oxygen is contained, it is known to polymerize significantly and sometimes explosively. Therefore, when storing TFE, about 100 to 10,000 ppm of polymerization inhibitors represented by terpenoids are added (US Pat. No. 2,737,533). In addition, it is disclosed that α-pinene, camphor, α-terpinene, D- Terpene mixtures such as limonene, γ-terpinene, p-cumene, terpinene, and rectification methods thereof (US Patent No. 3834996 specification). [0003] However, the polymerization preventing effect...

AI Technical Summary

Problems solved by technology

However, here, it is effective for preventing polymerization of TFE in the storage and transportation process, and has insufficient performance for preventing polymerization in the rectification process.

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