Patent EP-0174621-A3 (EP)
Title: Process for preparing ethylene homo- and copolymers with a ziegler catalytic system
IPC: C08F10/02
Filed: 1985-09-07
Abstract: 1. A process for the preparation of homopolymers of ethylene and copolymers of ethylene with minor amounts of C3 -C8 -alpha-monoolefins by polymerization of the monomer or monomers at from 30 to 200 degrees C and under from 1 to 200 bar by means of a Ziegler catalyst system consisting of (1) a titanium-containing catalyst component and (2) an aluminium-containing catalyst component of the formula AIR3 where R is a C1 -C12 -hydrocarbon radical, with the provisos that (i) the atomic ratio of titanium from the catalyst component (1) to aluminum from the catalyst component (2) is from 1:5 to 1:700 and (ii) the titanium-containing catalyst component (1) employed is the solid-phase product (VI) obtained by a procedure in which (1.1) first (1.1.1) a finely divided, porous, inorganic oxidic substance (I) having a particle diameter of from 1 to 1000 mu m, a pore volume of from 0.3 to 3 cm**3/g and a surface area of from 100 to 1000 m**2:g and of the formula SiO2 .Al2 O3 , where a is from à to 2, and (1.1.2) a solution (II) as obtained on combining (IIa) 100 parts by weight of an alcohol of the formula R**1-OH where R**1 is a saturated C1 -C8 -hydrocarbon radical, (IIb) from 0.01 to 6 parts by weight (calculated as titanium) of a titanium trichloride 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 ) are brought into contact with one another, with the formation of a dispersion (III), with the proviso that the weight ratio of inorganic oxidic substance (I) to titanium in the titanium trichloride (IIb) is from 1:0.01 to 1:0.2 and the weight ratio of inorganic oxidic substance (I) to magnesium in the magnesium chloride (IIc) is from 1:0.01 to 1:0.25, and the dispersion (III) is evaporated to dryness at a temperature which is below 200 degrees C and above the melting point of the alcohol (IIa) used, with formation of a solid-phase intermediate (IV), and (1.2) then (1.2.1) the solid-phase intermediate (IV) obtained from stage (1.1) and (1.2.2) an aluminium component (V) which is dissolved in an inert hydrocarbon and, in addition to aluminium, also contains a C1 -C12 -hydrocarbon radical are brought into contact with one another with formation of a dispersion, the solid-phase product (VI) obtained as a dispersion being the titanium-containing catalyst component (1), wherein the titanium-containing catalyst component (1) used is the solid-phase product (VI) which has been obtained from stage (1.2) by using in the said stage, as aluminum component (V), one which consist of (1.2.2.1) from 25 to 100 mol- % of a complex which is soluble in the inert hydrocarbon and is of the empirical formula  see diagramm : EP0174621,P10,F1  where Ph is phenyl or monomethyl-, dimethyl- or trimethylphenyl, Alk is C1 -C6 -alkyl, R**4 and R**5 are each a C1 -C12 -hydrocarbon radical and R**6 is a C1 -C12 -hydrocarbon radical or chlorine and (1.2.2.2) from 0 to 75 mol- % of an aluminum compound which is soluble in the inert hydrocarbon and is of the formula  see diagramm : EP0174621,P10,F2  where R**4 and R**5 are each a C1 -C12 -hydrocarbon radical and R**6 is a C1 -C12 -hydrocarbon radical 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) to aluminum in the aluminum component (V) is from 1:1 to 1:30.