Method for preparing fluorine-containing rubber used for paint

Abstract

The invention provides a preparation method of fluororubber used in paint, which uses free radical emulsion polymerization, uses water as disperse medium, and uses 0.001-5 weight account of fluorine emulsifier in each 100 weight account of water medium, uses 50-80% chlorotrifluoroethylene and 20-50mol% vinylidene fluoride as polymerization monomers, uses organic hyperoxide as initiator, uses 0.001-5 weight account of initiator in each 100 weight account of water medium, keeps polymerization monomer component constant in polymerization until the number average molecular weight of fluororubber is 50-450 thousand, uses freezing aggregation method after reaction to obtain the fluororubber product with high stability, better low permeability, improved solubility, effective controlled molecule structure and distribution, improved regularity and symmetry of molecular chain, reduced low-molecular-weight portion, and the application for resolving low solubility, sagging and wiring problems of fluorine paint in construction. The product can be used as paint to be dissolved into low-molecular-weight organic solvent to be used directly.

Description

Technical field [0001] The invention relates to a method for preparing fluororubber used as a coating, and in particular to a free radical emulsion polymerization method for producing fluororubber. Background technique [0002] Fluorinated copolymers are widely used in construction, industry, chemical industry and other fields because of their good weather resistance, chemical resistance and oil resistance. Among them, it is divided into fluororesin, which is often used as paint, and fluororubber, which is used as seal products. Fluorine rubber has excellent resistance to high and low temperature, oil and chemicals, and has been widely used in various sealing products. Because of its excellent coating performance, it is also often used in coatings. When used as a coating, it is usually The construction is carried out in the form of emulsion, and a very small part of the construction is carried out by directly dissolving rubber in a mixed solvent to make enamel paint. [0003] Alt...

AI Technical Summary

Problems solved by technology

[0003] Although ordinary fluororubbers can be dissolved in low-molecular ketones and esters, their acid and alkali resistance and coating performance cannot be compared with the same type of fluororesin, especially F23 type fluororubber, because it contains a considerable amount of Chlorotrifluoroethylene structural monomer, so it has very excellent corrosion resistance, and its chlorine content increases in direct proportion to its corrosion resistance, that is, the higher the chlorine content, the better its corrosion resistance, but its relatively high chlorine content , it will change its structure to plastic because of its high crystallization, and its solubility will become poor. The prepared glue has high viscosity, which is not conducive to the construction of coatings.