A fluoropolymer that does not contain PFOA or PFOS

Abstract

The invention discloses a fluorine-containing polymer free of perfluoro-octanoic acid or perfluoro-octylsulfonic acid. One or more fluorinated monomers is / are subjected to liquid polymerization by using polyfluothane oxy ether acid as an emulsifier to obtain the fluorine-containing polymer free of perfluoro-octanoic acid or perfluoro-octylsulfonic acid, wherein the polyfluothane oxy ether acid is a halogen-terminated or hydrogen-terminated polyfluothane oxy ether acid emulsifier. The technical scheme mainly relates to the following three improvements: (1) the polyfluothane oxy ether acid or salt thereof selected instead of PFOA / PFOS as the fluorine-containing emulsifier can be effectively used in aqueous emulsion polymerization reaction of fluorinated monomers; (2) the prepared fluorine-containing polymer is free of perfluoro-octanoic acid or perfluoro-octylsulfonic acid, and thus, satisfies the environmental requirement; and (3) the fluorine-containing polymer conforms to the cost accounting, can greatly enhance the single-kettle yield of the equipment on the premise of not increasing the production equipment and personnel, and meanwhile, can enhance the polymerization time, polymerization yield and other production indexes.

Description

technical field [0001] The invention relates to the field of synthesis of fluorine-containing polymers, specifically, a fluorine-containing polymer without perfluorooctanoic acid or perfluorooctanoic acid. Background technique [0002] Fluoropolymer is a general term for alkane polymers in which some hydrogen atoms are replaced by fluorine atoms. It is also a special kind of polymer material, which can be polymerized by one or more fluorine-containing monomers under certain conditions. The fluorine-carbon bond with high bond energy in its structure and the shielding effect of fluorine atoms on the molecular chain make it have a series of excellent characteristics, such as: excellent chemical corrosion resistance, dielectric properties, weather resistance, non-stickiness, excellent Friction properties, etc. Of course, due to its excellent performance, fluoropolymers have become one of the indispensable materials in many fields such as modern technology, national defense, elec...

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Problems solved by technology

[0005] From the content disclosed in the above patent documents, we can also know that the existing disclosed fluorine-containing emulsifiers are all effective. Although the toxicological characteristics of fluorine-containing emulsifiers have been solved, none of them involve the production Product characteristics such as rate and particle size, taking the above-mentioned invention patent CN101218264B as an example, in this patent document, the comparison data of polymerization time, average particle size, SSG (particle specific gravity of fluoropolymer) and solid content are given, except polymerization time In addition, the rest of the data did not fluctuate significantly. It can be seen that although the existing fluorinated emulsifiers that do not contain PFOA have solved the possible harm to the human body caused by the high stability and refractory properties of PFOA / PFOS, they have no effect on the entire production process. The efficiency has not been substantially improved. At the same time, since the fluorine-containing emulsifier involved in the above invention patent CN101218264B is perfluoropolyether, we know that perfluoropolyether is composed of -CF2-O-CF 2 - such ether chains Composition, all the H atoms in the molecule are replaced by F atoms. From the perspective of industrial production, there is no way to achieve large-scale production. It is necessary to add a monomer whose terminal halogen is not F in the preparation process. As a chain transfer agent, industrial production can only be realized, and the production process is relatively complicated. Based on the increasingly fierce competition in the existing market, we must find a new fluorine-containing emulsifier, which can not only replace the use of PFOA / PFOS, but also Based on product performance, long-term and effective economic benefits can be obtained

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