Process for producing polytetrafluoroethylene molding powder and process for producing polytetrafluoroethylene agglomerated product
US9718930B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2015 |
| Grant date | Aug 1, 2017 |
| Priority date | — |
| Expiry date | Jul 13, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/098
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
To provide a process for producing a PTFE molding powder having a high bulk density from granular polymer particles without using an emulsifying agent having problems of bioaccumulation and toxicity. A process for producing a polytetrafluoroethylene molding powder, which comprises a step of suspension-polymerizing a monomer containing at least 99.8 mass % of tetrafluoroethylene in an aqueous medium to produce granular polymer particles and a step of milling the granular polymer particles, wherein the aqueous medium contains a compound represented by RF(OCF(X1)CF2)k-1OCF(X2)COO−M+, at a concentration of from 0.5 to 2,000 ppm. RF is a perfluorinated C1-10 monovalent organic group, X1 and X2 are fluorine atoms, etc., and M+ is an ammonium ion or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.