METHOD FOR PRODUCTION OF POLYTETRAFLUOROETHYLENE AND COMPOSITION CONTAINING POLYTETRAFLUOROETHYLENE Russian patent published in 2025 - IPC C08F2/26 C08F214/26 C08F259/08 C08L27/18 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a method of producing polytetrafluoroethylene and compositions containing polytetrafluoroethylene. Method of producing polytetrafluoroethylene comprises steps of polymerising tetrafluoroethylene in an aqueous medium in the presence of polymer (1) in order to obtain polytetrafluoroethylene, wherein polymer (1) is a polymer of monomer (1), represented by general formula (1), which is obtained by a production method comprising polymerising monomer (1) to obtain polymer (1), during polymerisation, concentration of oxygen in the polymerisation reaction system is maintained at level of 0.01 to 1500 vol. parts per million. polymer (1) has a weight-average molecular weight of 1.4 × 10⁴ or more, content of polymerisation block (1) based on monomer (1) is 40 mol.% or more of the total amount of all polymerisation blocks making up polymer (1), and content of dimer and trimer of monomer (1) is 1.0 wt.% or less by weight of polymer (1). Monomer (1) is characterized by structural formula CF₂=CF(-O-Rf-A) (1), where Rf is a fluorine-containing alkylene group having 1–40 carbon atoms or a fluorine-containing alkylene group having 2–100 carbon atoms and having an ether bond or a keto group; and A is -COOM, -SO₃M, -OSO₃M or -C(CF₃)₂OM, where M is H, a metal atom, NR⁷₄, imidazolium, optionally having a substitute, pyridinium, optionally having a substitute, or phosphonium, optionally having a substitute, and R⁷ is H or an organic group, and polytetrafluoroethylene is a homopolymer of tetrafluoroethylene or a copolymer of tetrafluoroethylene and a modifying monomer with content of the block based on the modifying monomer of 0.00001 wt.% to 1 wt.%. Described also are compositions for making moulded articles, which contain polytetrafluoroethylene, having ratio of sides of primary particles less than 2, and a polymer in the presence of which polytetrafluoroethylene is obtained.

EFFECT: providing a method of producing polytetrafluoroethylene which enables to obtain compositions which virtually do not contain dimers and trimers of monomers which make up the polymer used for polymerisation of polytetrafluoroethylene.

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