Abstract: A novel process for the preparation of a chlorinated polyolefin having excellent low temperature characteristics and brightness is provided which comprises allowing a polyolefin dissolved or suspended in a solvent to undergo chlorination reaction with chlorine gas or chlorinated sulfuryl in the presence of a radical initiator as a catalyst, characterized in that as said solvent there is used 1,1,2-trichloroethane and the temperature is controlled to 90.degree. C. or lower at the process for removing hydrogen chloride and/or sulfur dioxide by-produced during the reaction from the reaction system.

Abstract: A novel process for the preparation of a chlorinated polyolefin having excellent low temperature characteristics and brightness is provided which comprises allowing a polyolefin dissolved or suspended in a solvent to undergo chlorination reaction with chlorine gas or chlorinated sulfuryl in the presence of a radical initiator as a catalyst, characterized in that as said solvent there is used 1,1,2-trichloroethane and the temperature is controlled to 90.degree. C. or lower at the process for removing hydrogen chloride and/or sulfur dioxide by-produced during the reaction from the reaction system.

Abstract: A process for producing a chlorinated polyolefin is disclosed, which comprises dissolving or suspending a polyolefin in a solvent and conducting chlorination reaction of the dissolved or suspended polyolefin, said solvent being a chloroform-based solvent comprising a mixture of 100 parts by weight of chloroform containing no alcohol and from 0.0005 to 15 parts by weight of a compound having from 4 to 10 carbon atoms and containing one or more double bonds per molecule. A process for producing a chlorosulfonated polyolefin is also disclosed, which comprises dissolving or suspending a polyolefin in a solvent and conducting chlorination and chlorosulfonation reaction of the dissolved or suspended polyolefin, said solvent being a chloroform-based solvent comprising a mixture of 100 parts by weight of chloroform containing no alcohol and from 0.0005 to 15 parts by weight of a compound having from 4 to 10 carbon atoms and containing one or more double bonds per molecule.

Abstract: A process for producing a chlorinated polyolefin is disclosed, which comprises dissolving or suspending a polyolefin in a solvent and conducting chlorination reaction of the dissolved or suspended polyolefin, said solvent being a chloroform-based solvent comprising a mixture of 100 parts by weight of chloroform containing no alcohol and from 0.0005 to 15 parts by weight of a compound having from 4 to 10 carbon atoms and containing one or more double bonds per molecule. A process for producing a chlorosulfonated polyolefin is also disclosed, which comprises dissolving or suspending a polyolefin in a solvent and conducting chlorination and chlorosulfonation reaction of the dissolved or suspended polyolefin, said solvent being a chloroform-based solvent comprising a mixture of 100 parts by weight of chloroform containing no alcohol and from 0.0005 to 15 parts by weight of a compound having from 4 to 10 carbon atoms and containing one or more double bonds per molecule.