Purification method and preparation method for carbonyl fluoride

Abstract

The invention provides a purification method for carbonyl fluoride. The purification method comprises the steps that purifying gas is used for reacting with impurities in gas of a crude carbonyl fluoride product to remove the impurities in the gas of the crude carbonyl fluoride product, wherein the purifying gas is any one or more of ClF, ClF3, ClF5 and F2. According to the purification method, the crude carbonyl fluoride reaction product is purified, any one or more of ClF, ClF3, ClF5 and F2 are adopted as the purifying gas to react with the crude carbonyl fluoride reaction product in a purification device, various impurities, especially CO2, CO, H2O, phosgene COCl2, N2O and the like, except carbonyl fluoride are removed, and the content of impurities is greatly reduced. In purified fine carbonyl fluoride gas, the purity of COF2 is larger than or equal to 99.95%, the content of CO2 is smaller than or equal to 150*10<-6> (the volume ratio), and the content of COCl2 is smaller than or equal to 150*10<-6> (the volume ratio).

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a purification method and preparation method of carbonyl fluoride. Background technique [0002] At present, in the field of semiconductor and liquid crystal manufacturing, perfluorocarbons are mostly used as etching gases and cleaning gases, but the above-mentioned gases usually have a large global warming potential (GWP, Global Warming Potential) value. In order to reduce the greenhouse effect, it is necessary to develop Alternative products with low GWP value. [0003] Carbonyl Fluoride (COF 2 ) is a semiconductor etching gas with a low GWP value, a semiconductor cleaning gas, and a fluorinating agent and an important intermediate in organic synthesis. [0004] At present, the production and preparation methods of carbonyl fluoride are generally divided into the following four types: [0005] 1) The method of reacting carbon monoxide or carbon dioxide with fluorin...

AI Technical Summary

Problems solved by technology

[0005] 1) The method of using carbon monoxide or carbon dioxide to react with fluorinating agents such as fluorine gas and silver difluoride; this method is prone to explosion, and requires expensive corrosion-resistant materials, and the prepared carbonyl fluoride yield and purity are low

[0006] 2) Using phosgene COCl 2 A method of reacting with fluorinating agents such as hydrogen fluoride, antimony trifluoride, arsenic trifluoride, and sodium fluoride; the raw material phosgene used in this method is a highly toxic substance, and the purity of the prepared carbonyl fluoride is low

[0008] 4) The method of reaction between tetrafluoroethylene and oxygen is adopted; during the reaction process of this method, a very large reaction heat will be generated, which has the danger of explosion

Among them, COF 2 The boiling point is -84.57°C, CO 2 The boiling point of is -78.45°C, due to the small difference in boiling point approach, the difference in boiling point is only ~6°C, and the COF 2 and CO 2 The molecular physical and chemical properties and molecular size are relatively close, and it is difficult to purify and separate through the usual adsorption method and rectification method

At the same time, since they all react easily with alkaline substances, it is difficult to separate them by neutralization

Currently for COF 2 Medium CO 2 Purification, there are few domestic and foreign patents to report

Images