Preparation method of narrow-particle-size suspension polytetrafluoroethylene resin

Abstract

The invention discloses a preparation method of narrow-particle-size suspension polytetrafluoroethylene (PTFE) resin. The method comprises the following steps: 1, tetrafluoroethylene is used as a polymerization monomer, materials are prepared, and polymerization is performed to prepare suspension polytetrafluoroethylene resin; 2, when a content of deionized water is 100 parts, a content of a di-tert-butyl peroxide is 1.14 x 10<-2> parts, a content of ferrous naphthenate is 2.28 x 10<-2> parts, and a content of perfluorocycloether is 2.28 x 10<-3> parts; 3, the polymerization starting temperature is 40 DEG C, the temperature is maintained at 40-60 DEG C in the polymerization process, the reaction pressure is a constant value between 1.6-3.0 MPa of gage pressure, a constant-pressure reactionis performed, and the ferrous naphthenate is added into a reaction kettle in a form of a dilute solution with a mass percentage concentration of 1% at a constant speed within 90 min; and 4, the material obtained in the step 3 is repeatedly washed for three times or more by using deionized water until measured conductivity of the filtrate is reduced to 1 [mu]S / m or less; and drying is performed ata temperature not higher than 200 DEG C.

Description

technical field [0001] The invention relates to a preparation method of narrow particle diameter suspended polytetrafluoroethylene PTFE resin, which belongs to the technical field of fluorine-containing plastics and preparation methods thereof. Background technique [0002] The difference in the quality of suspended PTFE resins is due to their different particle sizes, particle size distributions, and particle shapes. Therefore, the narrower the particle size distribution range, the more targeted the application and the lower the probability of "defect points". The processing performance and product performance of the product are better. [0003] Among the common polymerization initiators, inorganic peroxides (such as ammonium persulfate, etc.) are low in cost and do not require special solvents, but inorganic peroxides are water-soluble initiators, which will make a small amount of tetrafluoroethylene monomer dissolved in water Polymerized into "impurities" whose molecular...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a preparation method of narrow particle diameter suspended polytetrafluoroethylene PTFE resin, mainly in order to solve the technical problem that the self-decomposition excessive speed that exists in the polymerization reaction of organic initiator causes the molecular weight and the particle size distribution scope to enlarge