| 摘要 |
1408611 Titanium trichloride polymerization catalyst SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV 22 Aug 1973 [6 Oct 1972] 46222/72 Heading C3P Unsaturated hydrocarbons are polymerized in the presence of a catalyst obtained by (a) reducing TiCl 4 by gradually adding at least 0À9 molar parts of TiCl 4 to 1 molar part of a trialkylaluminium at a temperature below 220‹ K., (b) bringing the temperature to between 220‹ K. and 270‹ K., (c) adding and reducing at this temperature range more TiCl 4 and adjusting, if necessary, the total amount of dialkyl aluminium halide so as to obtain a molar ratio of TiCl 4 to dialkyl aluminium halide of from 2 : 1 to 1 : 2, and (d) subsequently raising the temperature to between 350‹ and 570‹ K. to convert the beta-TiCl 3 to gamma-TiCl 3 . The catalyst is activated by addition of further dialkyl aluminium halide. Optionally the above procedure may be modified by raising the temperature of the reaction mixture between steps (a) and (b) to above 290‹ K. and below 350‹ K. and the product of step (d) may be treated with Lewis bases such as ethers, alkanes or trialkyl aluminiums, or may be treated with sufficient propene, in liquid diluent and with heating, to produce a small amount of polymer associated with the catalyst, prior to the polymerization proper. In the examples catalysts are prepared according to the above procedures and used to prepare polypropylene and propylene-b-ethylene-co-propylene copolymer. |
