METHOD OF SEPARATION OF BUTYL HALOGENATED RUBBER Russian patent published in 2002 - IPC

FIELD: production of butyl halogenated rubbers. SUBSTANCE: method of separation of butyl halogenated rubber solution of hydrocarbon solvent includes aqueous washing-off of rubber solution, distilling hydrocarbon solvent by aqueous degassing of rubber at several stages and separation of rubber in worm-type drying units. According to proposed method, additional washing-off of rubber solution is first performed at its with vapors of degassing process discharged from rubber aqueous degassing stage after which dispersion of rubber solution is directed together with hot circulating water for degassing; first-stage degassing of rubber is conducted at temperature of 90 to 105 C and pressure of 0.17 to 0.22 MPa; at second stage, gas content of rubber dispersion in water is reduced at pressure of 0.12 to 0.17 MPa and dispersion is directed to third stage for final degassing at temperature of 85 to 95 C and pressure of 0.075 to 0.085 MPa. Butyl rubber solution is washed off after halogenation before stage of additional washing-off of butyl halogenated rubber to remove acid products by demineralized water or condensate at pH equal to 2.0 to 6/5 performing neutralization by aqueous alkali solution. EFFECT: increased degree of extraction of metal from rubber; enhanced efficiency of washing off hydrogen halides; reduced destruction of rubber at degassing. 1 dwg