Process for preparing homo- and copolymers of alpha-monoolefins by means of a Ziegler catalyst system.

摘要

1. Process for the preparation of homopolymers and copolymers of C2 - to C6 -alpha-monoolefins by polymerization of the monomer or monomers at temperature of from 30 to 200 degrees C and under pressures of from 0.1 to 200 bar by means of a Ziegler catalyst system of (1) a titanium-containing catalyst component and (2) an aluminium compound of the formula AIA3-n Xn wherein A represents a C1 - to C12 -hydrocarbon radical, X represents chlorine, bromine or hydrogen and n represents a number from 0 to 2, with the proviso that the atomic ratio of titanium from catalyst component (1) : aluminum from catalyst component (2) is in the range from 1:0.1 to 1:500, and that (1.1) to prepare catalyst component (1) (1.1.1) a titanium compound (I), which is solid under normal conditions, from the series comprising chlorides, oxychlorides and alkoxy chlorides of trivalent or tetravalent titanium in which the alkoxy groups can each contain up to 8 carbon atoms, and mixed chlorides of trivalent titanium of the formula TiCI3 .Z(AICI3 ) wherein Z is a number less than 0.5, and (1.1.2) a halogen compound (II) which has been obtained from a substance (III) of the general formula (Me**II )6 .(Me**III )2 .(OH)16 .(CO3 )1 .(H2 O)4 wherein Me**II represents magnesium, calcium, zinc or manganese and Me**III represents aluminum or chromium, while keeping the substance hot at a temperature of from 150 to 600 degrees C for from 1 to 100 hours and then chlorinating the substance to a chlorine content of the material of from 40 to 76 per cent by weight, are ground with one another in the dry state in a weight ratio of titanium compound (I) : halogen compound (II) of from 1:200 to 1:2 over a period of from 5 to 100 hours with a grinding acceleration of from 4 to 6 m/s**2 , to form a solid-phase ground product (IV), wherein, in the preparation of catalyst component (1) (1.2) in an additional stage (1.2.1) the ground product (IV) obtained according to (1.1) (1.2.2) a C1 - to C12 -alkanol (V) and (1.2.3) a C5 - to C12 -alkane (VI) are brought together in the weight ratios of ground product (IV) : alkanol (V) of from 1:0.01 to 1:1 and ground product (IV) : alkane (VI) of from 1:1 to 1:1,000, to form a suspension (VII) and the entire mixture is kept at a temperature of from 0 to 195 degrees C over a period of 0.5 to 60 minutes, with continuous thorough mixing, and then (1.3) - where appropriate - in a subsequent stage (1.3.1) the suspension (VII) obtained according to (1.2) is mixed with (1.3.2) a metal compound (VIII) of the general formula Mt Gs-t Et where Mt represents the metals aluminium or silicon, G represents a C1 - to C12 -hydrocarbon radical, E represents chlorine, bromine, hydrogen or a radical -OD, D represents a C1 - to C12 -hydrocarbon radical, s represents the valency number of the metal Mt and t represents a number from (a) 0 to s - 1, if Mt is aluminum, or (b) 0 to 4, if Mt is silicon, while maintaining the mixture in the state of a suspension, until the atomic ratio of titanium from the solid contained in the suspension (VII) : metal from the metal compound (VIII) is in the range from 1:0.5 to 1:20 ; the solid-phase product which results from stage (1.2) or (1.3) and is in suspension being the titanium-containing catalyst component (1).