METHOD OF EXTRACTING BUTADIENE-NITRILE RUBBER FROM LATEX Russian patent published in 2012 - IPC C08C1/15 C08C1/14 C08F6/14 C08F6/22 

FIELD: chemistry.

SUBSTANCE: method of extracting butadiene-nitrile rubber from latex is carried out by feeding sodium sulphite or sodium bisulphite or sodium pyrosulphite in amount of 0.05-0.8 wt % per latex, into a stream of latex degassed beforehand, into which an antioxidant emulsion is also fed. Further, the stream of latex, containing sulphite, is directed into a coagulation apparatus into which aqueous sulphuric acid and an organic amine coagulant in form of a quaternary polymer ammonium salt are also simultaneously fed, said salt being selected from: polydimethyl diallyl ammonium chloride, a methacrylamide and dimethyl aminoethyl methacrylate hydrochloride copolymer, and polydiethyl aminoethyl methacrylate hydrochloride. The amount of the polymer ammonium salt varies from 0.2-0.5 wt %, per rubber, depending on content of leukanol content in latex in the range of 0.1-0.4 wt %, per rubber, at coagulation pH 3-6 and temperature 30-70°C.

EFFECT: invention improves environmental friendliness of the process, specifically reduces content of unreacted monomer - free acrylic acid nitrile, avoids excess synthetic coagulant and the amount of salt used for coagulation.

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