| 摘要 |
A process for the preparation of homopolymers and copolymers of alpha -monoolefins by means of a Ziegler-Natta catalyst system comprising (1) a titanium-III component, which is prepared by subjecting (1.1) a titanium trichloride/aluminum trichloride compound (a) and (1.2) an ester (b) to a certain type of milling treatment in which (A) a vibratory ball mill providing a relatively high milling acceleration is used, (B) the mill is first charged with the titanium-containing compound (a) and, if appropriate, is run for a certain period, thereafter (C) the ester (b) is added at a certain rate while milling the charge, thereupon (D) the charge is kept at +15 DEG C. or above for a certain period, while continuing the milling, hereupon (E), if appropriate, the product obtained from (D) is milled further for a certain period at +5 DEG C. or below, then (F), if appropriate, but advantageously so, the product obtained from (D) or (E) is kept at +20 DEG C. or above for a certain period, without milling, and thereafter (G), if appropriate, the product obtained from (F) is milled further for a certain period at +5 DEG C. or below, (2) an aluminum-alkyl component containing a chlorine bonded to the aluminum, and (3), if appropriate, a phenolic compound of a certain category, in which process a titanium-III component (1) is employed, in the preparation of which additionally -(H) a suspension is prepared from (H1) the product obtained according to (D), (E), (F) or (G), (H2) a liquid hydrocarbon (c) and (H3) an oxygen-containing compound (d), consisting of (d1) an ether of a certain category and/or (d2) an ester of a certain category, thereafter (I) the suspension obtained according to (H) is kept at an elevated temperature for a certain period, with vigorous agitation, and is then cooled, hereupon (J), if appropriate, the solid is isolated from the suspension obtained according to (I), and, if desired, is washed with a liquid hydrocarbon and dried, the novel titanium-III component (1) being the solid, in suspended form, obtained according to (I) or the solid, in isolated form, obtained according to (J). Using this Ziegler-Natta catalyst system, polymers with relatively high stereo-regularity and advantageous morphological properties can be obtained in relatively high yield. |
