Verfahren zur Herstellung von Polyolefinen

摘要

1,174,542. Two-stage olefin polymerization. FARBWERKE HOECHST A.G. 29 Jan., 1968 [28 Jan., 1967], No. 4591/68. Heading C3P. Homopolymers of ethylene or copolymers of ethylene with up to 10% of another alphaolefin are made by polymerizing the monomer or monomers in either (a) a liquid dispersing medium in contact with a gaseous phase, or (b) a gaseous phase, at a pressure up to 10 atmospheres and a temperature between 50 and 120‹ C. in the presence of a catalyst comprising (1) for (a) from 0À05 to 0À3 millimol per litre of medium and for (b) per 0À5 litre of reactor of a trivalent titanium compound containing chlorine and (2) from 0À1 to 3À0 millimol of Al per litre of dispersing medium or per litre of reaction volume, of a trialkyl aluminium compound, or a reaction product of an aluminium trialkyl or aluminium alkyl hydride with a diolefin, and conducting the polymerization in two stages, i.e. stage one being carried out in the presence of 0 to 10% of hydrogen to give a polymer containing 5 to 30% by weight of the total polymer, and stage two in the presence of 20 to 80% of hydrogen to give the remainder of the total polymer. The amount of the catalyst present in the first stage is sufficient for both stages. In the examples the catalyst component (1) is made by reacting ethylaluminium sesquichloride with dichlorotitanic acid dipropyl ester, and component (2) is aluminium isoprenyl or aluminium triisobutyl. The polymers prepared are in Example I, in both stages a copolymer of ethylene and butene-1, in Example II, a copolymer of ethylene and butene- 1 in stage one and polyethylene in stage two, and in Example III, in stage one polyethylene and in stage two a copolymer of ethylene and butene-1.