| abstract |
FIELD: chemistry. n SUBSTANCE: invention relates to a method of polymerisation for obtaining a polypropylene polymer composition. The method is performed in the presence of a system of catalysts, containing (a) solid catalytic component, which has an average size of particles from 15 to 80 mcm, containing magnesium halogenide, titanium compound, possessing, at least, a bond Ti-halogen, and, at least, two electron-donor compounds, one of which is present in an amount from 50 to 90 wt % relative to the total quantity of donors, one of which is selected from succinates, and the second is selected from 1,3-diethers, (b) alkylaluminium and, optionally, (c) internal electron-donor compound. The method includes contact of the catalytic components (a), (b) and, optionally, (c), then, preliminary polymerisation to a degree of pre-polymerisation from 0.1 to 1000 g per gram of the solid catalytic component (a), then polypropylene polymerisation with obtaining a propylene (co)polymer, at least, 85 wt % of which are not soluble in xylene at 25°C, and the following stage, carried out in a gas phase, polymerisation of the mixture of ethylene with α-olefins CH 2 =CHR, where R is a hydrocarbon radical, containing 1-10 carbon atoms, with obtaining an ethylene copolymer. n EFFECT: obtaining shock-resistant polypropylene compositions with the application of the catalytic system, capable of suggesting simultaneously high polymerisation activity, good morphologic stability, optimal inclusion of the xylene-soluble phase, high isotacticity, such that the final composition has a good balance between shock-resistance and rigidity. n 13 cl, 1 tbl, 5 ex |