Patent EP-0174620-A3 (EP)
Title: Process for preparing ethylene homo- and copolymers with a ziegler catalytic system
IPC: C08F4/64
Filed: 1985-09-07
Abstract: 1. A process for preparing a homopolymer of ethylene or a copolymer of ethylene with a minor amount of a C3 -C8 - -monoolefin by polymerization of the monomer(s) at from 30 to 200 degrees C under from 1 to 200 bar by means of a Ziegler catalyst system comprising (1) a titanium-containing catalyst component and (2) an aluminum-containing catalyst component of the formula AIR**3 where R is C1 -C12 -hydrocarbyl, with the provisos that (i) the atomic ratio of titanium in catalyst component (1) : aluminum in catalyst component (2) is within the range from 1 : 5 to 1 : 700 and (ii) the titanium-containing catalyst component (1) used is the solid phase product (VI) obtained by (1.1) first (1.1.1) bringing into contact with each other a finely divided porous inorganic oxide substance (I) which has a particle diameter of from 1 to 1,000 m, a pore volume of from 0.3 to 3 cm**3 /g, a surface area of from 100 to 1,000 m**2 /g and the formula SiO2 . aAl2 O3 , where a is from 0 to 2, and (1.1.2) a solution (II) such as results on bringing together (IIa) 100 parts by weight of an alcohol of the formula R**1 -OH where R**1 is saturated C1 -C8 -hydrocarbyl, (IIb) from 0.01 to 6 parts by weight (calculated as titanium) of a titanium chloride of the formula TiCl3 . nAlCl3 , where n is from 0 to 0.5, and (IIc) from 0.01 to 4 parts by weight (calculated as magnesium) of magnesium chloride (MgCl2 ), to form a dispersion (III), with the proviso that the weight ratio of inorganic oxide substance (I) : titanium in the titanium trichloride (IIb) is within the range from 1 : 0.1 to 1 : 0.2 and the weight ratio of inorganic oxide substance (I) : magnesium in the magnesium chloride (IIc) is within the range from 1 : 0.01 to 1 : 0.25, and evaporating the dispersion (III) at a temperature which is below 200 degrees C and above the melting point of the alcohol (IIa) used to dryness, forming a solid phase intermediate (IV), and (1.2) then (1.2.1) bringing into contact with each other the solid phase intermediate (IV) obtained in stage (1.1) and (1.2.2) an aluminum component (V) dissolved in an inert hydrocarbon and, in addition to aluminum, containing a C1 -C12 -hydrocarbon radical, to form a dispersion where the resulting dispersed solid phase product (VI) is the titanium-containing catalyst component (1), which comprises using as the titanium-containing catalyst component (1) the solid phase product (VI) obtained in stage (1.2) by using therein as aluminum component (V) an aluminum component which is (1.2.2.1) from 25 to 100 mol-% a complex which is soluble in the inert hydrocarbon and has the empirical formula  see diagramm : EP0174620,P12,F1  where m is 2, 3 or 4, R**4 and R**5 are each C1 -C12 -hydrocarbyl and R**5 is C1 -C12 -hydrocarbyl or chlorine and (1.2.2.2) from 0 to 75 mol-% an aluminum compound which is soluble in the inert hydrocarbon and has the formula  see diagramm : EP0174620,P12,F2  where R**4 and R**5 are each C1 -C12 -hydrocarbyl and R**6 is C1 -C12 -hydrocarbyl or chlorine, with the provisos that (i) the sum of the mol-% under (1.2.2.1) and (1.2.2.2) is 100 and (ii) the atomic ratio of titanium in the solid phase intermediate (IV) : aluminum in the aluminum component (V) is within the range from 1 : 1 to 1 : 30.