METHOD OF PRODUCING A COMPOSITION CONTAINING MULTISTAGE POLYMER (VERSIONS), AND USE OF SAID COMPOSITION AS MODIFIER OF IMPACT STRENGTH OF THERMOPLASTIC POLYMERS Russian patent published in 2019 - IPC C08F279/02 C08L51/04 C08L67/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a composition containing a multistage polymer (embodiments), to the use of the composition. Method of producing a polymer composition containing a multistage polymer involves the following steps: a) polymerisation by emulsion polymerisation of monomer or mixture of monomers (A_m) to obtain during this stage one layer (A) containing polymer (A1) with glass transition temperature of -120 to 0 °C, b) polymerising by emulsion polymerisation in the presence of a polymer obtained in step a), a monomer or a monomer mixture (B_m) for obtaining at this subsequent stage layer (B) containing polymer (B1) having glass transition temperature of 45 to 150 °C, c) coagulation of multistage polymer with alkali metal salt, d) washing the multistage polymer, e) adjusting the pH after coagulation in range of 5 to 10, f) adding an aqueous solution or dispersion containing a phosphorus-containing compound, where the phosphorus has an oxidation state of +III or +V, wherein the polymer composition contains at least 350 ppm of phosphorus, where the phosphorus has an oxidation degree of +III or +V, wherein the alkali-earth metals in the form of traces or minor impurities are less than 30 parts per million of the polymer composition and the multivalent cations are less than 50 parts per million of the polymer composition.

EFFECT: technical result is compositions containing multi-stage polymer have satisfactory resistance to thermal aging, satisfactory impact characteristics at room and sub-zero temperatures.

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