PTFE-based aqueous dispersions

Compositions based on PTFE, homopolymer or modified, comprising for 100 parts of the component 1) PTFE:

• 1) an aqueous nanodispersion, or latex, of said homopolymer or modified PTFE, having a primary particle diameter from 5 to 100 nm, preferably from 10 to 80 nm;
• 2) from 3 to 45 parts by weight, preferably from 5 to 30 parts by weight, of a surfactant or surfactant mixtures;
• 3) from 0.2 to 20 parts by weight, preferably from 0.4 to 10 parts by weight of an organic or inorganic sequestrant capable to give bi- or poly- coordination bands, which forms with metal ions soluble complexes and prevents from forming insoluble salts of said metals;
• and optionally:
• 4) from 0 to 60 parts by weight, preferably from 0 to 50 parts by weight of a solid lubricating compound, preferably selected from the following:
• sulphides and selenides of the transition elements belonging to the groups VB and VIB of the Element Periodic Table, preferably molybdenum and tungsten,
• carbon compounds as graphite and C60 and C70 fullerenes.