METHOD OF PRODUCING AQUEOUS DISPERSION OF PERFLUOROELASTOMER, COMPOSITION, CROSS-LINKED COMPOSITION AND CROSS-LINKED PRODUCT Russian patent published in 2024 - IPC C08F214/18 C08F2/16 C08L27/12 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing an aqueous dispersion of perfluoroelastomer. Described is a method of producing an aqueous perfluoroelastomer dispersion by polymerisation of a perfluoromonomer in the presence of polymer (1) and an aqueous medium to produce an aqueous perfluoroelastomer dispersion, wherein polymer (1) contains unit (1) based on monomer (1) of general formula (1), and polymer (1) has ion-exchange capacity of 1.50 mEq/g or more: CF₂=CF-R-CZ¹Z²-A⁰ (1), where R is a linking group; each of Z¹ and Z² independently represents F or CF₃; and A⁰ is an anionic group, where the perfluoroelastomer refers to a fluoropolymer having a perfluoromonomer block content of 90 mol.% or more, in terms of all polymerisation units, said fluoropolymer has a glass transition temperature of 20 °C or lower, melting peak (ΔH) 4.5 J/g or less, and has a concentration of fluorine atoms of 71 wt.% or more. Also described is a method of producing a cross-linkable composition comprising obtaining said aqueous dispersion and then mixing this aqueous dispersion or perfluoroelastomer obtained by extraction from the aqueous dispersion with at least one substance selected from a group consisting of an inorganic nitride, an organotin compound, an ammonia-forming compound and a cross-linking agent. Described is a method of producing a cross-linked product, comprising obtaining said cross-linked composition, and then cross-linking to obtain a cross-linked product. Also described is a composition for producing a cross-linked product containing a perfluoroelastomer and polymer (1) containing polymerisation unit (1) based on monomer (1) of general formula (1), and having an ion-exchange capacity of 1.50 mEq/g or more: CF₂=CF-R-CZ¹Z²-A⁰ (1), where R is a linking group; each of Z¹ and Z² independently represents F or CF₃; and A⁰ is an anionic group, where the perfluoroelastomer refers to a fluoropolymer having a perfluoromonomer block content of 90 mol.% or more, in terms of all polymerisation units, said fluoropolymer has a glass transition temperature of 20 °C or lower, melting peak (ΔH) 4.5 J/g or less and has a concentration of fluorine atoms of 71 wt.% or more. Described is a cross-linked composition for producing a cross-linked product containing said composition and at least one substance, selected from a group consisting of an inorganic nitride, an organotin compound, an ammonia-forming compound and a cross-linking agent. Described is a cross-linked product obtained by cross-linking said cross-linkable composition.

EFFECT: obtaining a sufficient amount of perfluoroelastomer particles with a sufficient polymerisation rate while inhibiting adhesion of the perfluoroelastomer to the polymerisation reactor.

25 cl, 1 tbl, 13 ex