| 摘要 |
<p>Olefins of formula CH2=CHR where R is an alkyl group are polymerized to polymers having a predominant content of isotactic macromolecules using a catalyst comprising a monoalkyl aluminium dihalide, violet crystalline titanium trichloride and an "onium" halide, the molar ratio of monoalkyl aluminium dihalide to "onium" halide being in the range 0,5/sB0,1. Specified olefins are propylene, butene and 4-methyl-pentene-1. The onium compound may be a tetraalkylammonium, tetraalkylphosphonium, trialkyloxonium or trialkylsulphonium halide. Polymerization may be effected in the presence of inert diluents, e.g. n-heptane and toluene. The titanium trichloride may contain other metal halides, e.g. aluminium chloride, in solid solution. Examples describe the polymerization of propylene in the presence of catalysts comprising titanium trichloride with ethyl aluminium dichloride and (1) triethyl sulphonium iodide, (2) tetrabutyl ammonium iodide, (3) tetrabutyl phosphonium iodide and (6) tetramethyl ammonium chloride; ethyl aluminium dibromide and (4) p tetrabutyl ammonium iodide and (5) tetrabutyl ammonium bromide; (7) ethyl aluminium diiodide and tetrabutyl ammonium iodide; and (8) methyl aluminium dichloride and triethyl sulphonium iodide, methyl aluminium dibromide and tetrapropyl phosphonium bromide, isobutyl aluminium dichloride and tetramethyl ammonium iodide, n-butyl aluminium dibromide and tetrapropyl ammonium iodide, hexyl aluminium di chloride and tetraethyl ammonium bromide, pentyl aluminium dichloride and tetramethyl ammonium chloride, and methyl aluminium diiodide and tetrapentyl ammonium iodide.</p> |
