GRANULATED POWDER MADE OF MODIFIED POLYTETRAFLUOROETHYLENE AND ITS VARIANTS, FORMED ARTICLE AND CUT OFF PLATE BASED ON THEREOF Russian patent published in 2002 - IPC

FIELD: technology of polymers. SUBSTANCE: invention relates to granulated powder made of the modified polytetrafluoroethylene used as the base for making formed articles and cut off plate. Powder is produced by granulation of the modified polytetrafluoroethylene in water in the presence of nonionic surface-active substance comprising hydrophobic and hydrophilic segments and organic liquid that forms interphase surface liquid/liquid with water. Modified polytetrafluoroethylene is produced by copolymerization of 99.0-99.999 mole % of tetrafluoroethylene and 0.001-1.0 mole % of perfluoro(vinyl ester). The obtained granulated powder shows the following parameters: electrostatic discharge, 50 V, not above; angle of natural slope, >38^°,, not above; apparent density, 0.7 g/cm³, not above; mean size of particles, 150 mcm, not less, 250 mcm, not less (fluidity is (f) 2-3 s/50 g) and stability of particles (s) is 2-3 s/50 g; mean size of particles 250- 1000 mcm with fluidity 1-2 s/50 g and stability of particles 1-2 s/50 g; coefficient of stability (s/f) is 1-1.3. Invention ensures to make the formed article with a smooth surface and enhanced elongation. EFFECT: improved quality and properties of powder. 8 cl, 4 dwg, 2 tbl