METHOD FOR PREPARING STYRENE-ACRYLIC COPOLYMERS AQUEOUS DISPERSIONS Russian patent published in 2005 - IPC

FIELD: chemical industry, chemical technology, polymers.

SUBSTANCE: invention relates to a method for preparing aqueous polymer dispersions of the multipurpose designation. Method for preparing an aqueous dispersion of styrene-acryl copolymer is carried out by preliminary emulsifying a mixture of acrylic monomers with styrene in the presence of emulsifying agent and the following aqueous-emulsion co-polymerization of the reaction mixture in the presence of initiating agent. Monomer mixture comprises additionally acrylamide, and method involves using ammonium persulfate and hydrogen peroxide as an initiating agent. Method involves the successive fractionally dosing feeding ammonium persulfate for two stages followed by addition of a mixture of polymethylsiloxane of molecular mass 55-1000 Da and iron sulfate in their mass ratio = (25-35):1 to the reaction mixture at stirring, cooling the reaction mass and its neutralization to pH = 5-6. Invention provides preparing the stable aqueous polymeric dispersion with diminished size of particles. Invention provides enhancing strength and water resistance of film prepared on its base.

EFFECT: improved preparing method.

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