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 step of tetrafluoroethylene, particularly a rectification step. 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 it contains a trace amount of oxygen, it is known that it polymerizes remarkably and sometimes explosively. Therefore, when storing TFE, about 100 to 10000 ppm of polymerization inhibitors typified by terpenoids are added (US Patent No. 2737533). In addition, it is disclosed that when rectifying TFE, in order to prevent self-polymerization of TFE in the rectifying tower, absorb oxygen in TFE at the same time, and reduce oxygen concentration, add α-pinene, camphorterpene, α-terpinene, D- Terpene mixtures such as limonen...

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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