A kind of polytetrafluoroethylene dispersion concentrated liquid and preparation method thereof

Abstract

The invention relates to the field of polymer materials, in particular to a polytetrafluoroethylene dispersed concentrated liquid and a preparation method thereof; the preparation method of the polytetrafluoroethylene dispersed concentrated liquid is as follows: taking tetrafluoroethylene monomer as a raw material through emulsion polymerization The polytetrafluoroethylene dispersion is obtained; the temperature of the emulsion polymerization reaction is 85±1°C; the present invention obtains uniform, large and plump primary particles with a uniform shape and a solid content of 43% by controlling the polymerization process; The polytetrafluoroethylene dispersion improves the output of a single tank and reduces the damage to large-diameter primary particles in the post-treatment vacuum concentration process, saves energy, and realizes environmental protection; the polytetrafluoroethylene dispersion concentrate obtained in the present invention has good dispersibility for fillers After sintering, the coating color is good, the coating surface gloss is excellent, the wear resistance is good, the adhesion is strong, the film-forming property is good, and the film-forming limit film crack thickness is high, which improves the application performance and service life of the coating film.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a polytetrafluoroethylene dispersion concentrate and a preparation method thereof. Background technique [0002] The excellent chemical corrosion resistance, high and low temperature resistance, aging resistance, low friction, non-stickiness, and physiological inertia of PTFE make it an indispensable special material in the fields of chemical industry, machinery, electrical, construction, and medical treatment. , it can be used for a long time in the temperature range of -250 ~ 250 ℃. With the rapid development of science and technology, people's awareness of environmental protection has increased, and their requirements for material and cultural living standards have become higher and higher, so high-function and multi-performance materials have emerged as the times require. Polytetrafluoroethylene coating is one of them. Because of its multifunctional properties such as heat r...

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Problems solved by technology

However, this patent document does not control the amount of modifiers and dispersants added in emulsion polymerization, and more surfactants are added in the post-treatment process, resulting in problems such as uneven particle morphology

[0005] Chinese patent document CN1568336A discloses tetrafluoroethylene-perfluorobutylethylene copolymer, specifically discloses a polymerization method for preparing tetrafluoroethylene and perfluorobutylethylene copolymer by aqueous dispersion polymerization technology and the resin prepared therefrom , the copolymer contains 0.02-0.6% by weight comonomer, the particle size of the copolymer is 0.175-0.203 microns, and the standard specific gravity is less than 2.143; the coating is made with the tetrafluoro concentrate containing the above-mentioned copolymer, and the coating occurs due to the small particle size Low thickness, easy to crack, low gloss, etc.

[0006] In the prior art, a dispersion with a solid content of 35% can be obtained by controlling the polymerization process, but the dispersion with a solid content of 43% produced by the prior art has demulsification, which in turn leads to solid-liquid separation and produces industrial waste , causing pollution to the environment

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