Low molecular weight polytetrafluoroethylene aqueous dispersion, production method of low molecular weight polytetrafluoroethylene powder and low molecular weight polytetrafluoroethylene

摘要

The present invention provides an aqueous dispersion of a low-molecular-weight polytetrafluoroethylene (PTFE), which contains an easily removable surfactant, and has a good dispersion stability. Specifically, the present invention provides an aqueous dispersion of a low-molecular-weight PTFE comprising tetrafluoroethylene (TFE) units, or TFE units and modifying monomer units which are copolymerizable with the TFE units, wherein the aqueous dispersion contains from 70 to 9,000 ppm, based on the aqueous dispersion, of a fluorine-containing compound of the formula (1) below: X—(CF2)m—Y  (1) where X is H or F; m is an integer from 3 to 5; and Y is —SO3M, —SO4M, —SO3R, —SO4R, —COOM, —PO3M2 or —PO4M2, M being H, NH4 or an alkali metal, and R being an alkyl group having 1 to 12 carbons, and the low-molecular-weight PTFE has an average primary particle size of from 100 to 350 nm.