Soap-free emulsion containing polytrifluorochloroethylene and its prepn

Abstract

The present invention describes soap-free emulsion polymerization process to prepare fluorous emulsion. The fluorous emulsion is prepared with trifluorochloroethylene as main component and through the ternary copolymerization of three kinds of monomer including trifluorochloroethylene, alphatic olefine ester and alphatic olefine acid; and has homogeneous grains and high storage stability. The copolymerization is completed in a high pressure reactor with water, monomers and initiator, at 65-75 deg.c and 0.7-2.5 MPa condition for 20-45 hr. The fluorous emulsion has solid content of 21-35 %, and polymer number average molecular weight of 7000-9500, and may be stored stably for over 6 months without lamination and gelatinizing.

Description

(1) Technical field [0001] The invention relates to a fluorine-containing emulsion copolymer and a preparation method thereof, in particular to a ternary fluorine-containing polymer emulsion in which an emulsifier mainly composed of chlorotrifluoroethylene participates in a copolymerization reaction and a preparation method thereof. (2) Background technology [0002] The research on organic fluorine polymers began in 1938, when R. Plunkett of DuPont Corporation in the United States first synthesized organic fluorine polymers - polytetrafluoroethylene (PTFE), which was insoluble in organic solvents and difficult to shape. In 1982, Japan's Asahi Glass Co., Ltd. first developed Lumiflon, a fluororesin soluble in organic solvents and curable at room temperature (JP Patent Publication No. 61-57609), which can be used to prepare highly weather-resistant architectural coatings. However, the weakness of this solvent-based room temperature curing fluoropolymer is that it contains a l...

AI Technical Summary

Problems solved by technology

[0005] Use fluorocarbon surfactants to carry out emulsion polymerization of fluorine-containing functional monomers such as perfluoroalkyl acrylate and vinyl monomers. The polymerization mechanism is the same as that of ordinary emulsion polymerization. The conditions are simple and the operation is easy to control, and stable copolymerization can be obtained. Polymer emulsions, copolymer emulsions have good water resistance, oil resistance, weather resistance and corrosion resistance, but fluorocarbon surfactants are extremely expensive and cannot be used on a large scale

Cross-linkable fluorine-containing copolymers can be prepared by emulsion copolymerization of acrylate monomers and / or other vinyl monomers with surface-active fluorine-containing polymers as dispersion stabilizers, but the emulsifier-fluorine-containing Polymer synthesis is difficult, the polymerization conditions are harsh, and the operation is cumbersome

Fluorine-containing emulsion polymerization is carried out with a conventional emulsification system. Since the fluorine-containing monomer is water-repellent and oil-repellent, it is difficult for ordinary emulsifiers to adsorb on the surface of the fluorine-containing monomer, and the ideal emulsification effect cannot be achieved. The synthesized emulsion unstable

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