Patent ID: 8153757

Claim:
A solution process for polymerizing at least one α-olefin of formula CH 2 ═CHR, where R is H or an alkyl radical C 1-12 , to produce a polyolefin soluble in a reaction medium comprising olefin monomers, the process comprising: a) polymerizing said at least one α-olefin in a solution phase in the presence of a polymerization catalyst and an inert hydrocarbon solvent having a vapor pressure lower than 100 kPa at 20° C.; and b) separating the produced polyolefin from the olefin monomers and the inert hydrocarbon solvent by means of a sequence of at least three devolatilization chambers operating at decreasing pressures, the second devolatilization chamber being operated at a pressure of from 0.8 to 5 bar and a temperature of from 180 to 250° C.