METHOD OF PRODUCING CARBOXYLATED BUTADIENE-STYRENE LATEX Russian patent published in 2009 - IPC C08F2/24 C08F236/10 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of synthesis of carboxylated butadiene-styrene latex and can be used in different industries, particularly in production of water paints, water-resistant wallpapers, adhesives, in finishing carpets. Carboxylated butadiene latex is obtained through emulsion polymerisation of butadiene, styrene, methacrylic acid in the presence of an initiator, emulsifying agent - combination of nonionic surfactant with ionic emulsifying agents, molecular weight regulator, with subsequent linkage of unpolymerised monomers through introduction of a redox initiator system. Initially, 8 to 12% monomer emulsion, containing monomers, water and a mixture of emulsifying agents, is fed into a reactor, containing potassium persulphate in amount of 0.5 pts. wt. The process is carried out while stirring at temperature ranging from 76 to 80°C until conversion of not less than 70%. The remaining part of monomers is continuously fed in mass ratio monomer: polymer equal to 1:1.5-10 pts. wt. When monomer conversion of not less than 97% is attained, the redox initiator system is added to the latex, where the redox initiator system contains tert-butyl hydroperoxide and sodium formaldehyde sulphoxylate in amount of 0.2 to 0.05 pts. wt to monomer. The emulsifying agents used is a mixture of surfactant - sodium alkylbenzolsulfonate, nonionic emulsifying agent OP-10 and alkyl- or sodium or ammonium alkylphenol sulfoethoxylate in ratio 5-6:1:1 pts. wt.

EFFECT: improved operational and ecological properties of latex while using energy-saving technology.

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