Ziegler-Natta type catalyst system for polymerising propylene¨ - is based on solid component from titanium cpd., magnesium organo-oxy halide, halogen and carboxylic acid deriv., with aluminium cpd.

摘要

System (I) is based on (A) Ti-contg. solid component contg. (A1) Ti-cpd. (A2) Mg cpd. of formula Mg(OR1)X R1 = 1-10C alkyl, 6-10 C aryl, or alkylaryl or 5-7 membered cycloalkyl, opt. contg. 1-4C alkyl gps. X = Cl or Br, (A3) halogen (A4) carboxylic acid derivs. (B) Al cpd. and opt. (C) other electron donor cpds. Also claimed are (i) prepn. of (I) by (1) suspending finely divided carrier material in (II) in liq. alkane at 10-120 deg.C. (2) treating suspension with 0.1-10 M soln. of (A2) in liq. alkane (3) adding to this mixt. after 30-120 minutes at 10-150 deg.C 0.2-5 mol halogen or hydrogen halide per mol. Mg of (A2) (4) after 60-300 minutes treating reaction prod. at 10-150 deg.C with per mol. Mg 0.1-5 mol 1-8C alkanol 1-20 mol halide or alcoholate of 3- or 4-valent Ti and 0.01-1 mol. (A4), (5) filtering off solid (I) and washing (I) with liq. alkane, and (ii) prepn. of polymers (III) of propylene (IV) by polymerisation at 20-150 deg.C and 1-100 bar using (I). USE/ADVANTAGE - Prodn. of (IV) homopolymers and copolymers with minor amts. of other 2-12C alpha, beta-unsatd. olefinic cpds. (I) have higher productivity and improved stereospecificity partic. in gas phase polymerisation, (III) have very small proportion of fines (less than 0.2mm) low Cl content, and good mechanical properties. (6pp Dwg.No.0/0)