| 摘要 |
1465104 Polymers in fibrid form SNAMPROGETTI SpA 30 April 1974 [30 April 1973] 18959/74 Heading C3P Polymers in the form of particles of fibrid form are prepared by polymerizing at least one olefinically unsaturated compound in a solvent medium for the unsaturated compound(s) which is a non-solvent for the resulting polymer in the presence of a catalyst comprising (a) a vanadium or titanium compound and (b) a reducing aluminium compound AlR x X 3-x where R is hydrocarbyl, X is hydrocarbyl, halogen or hydrogen and x is 0 to 3 or a polyiminoalane having repeating units -(AlH-NR)-, the atomic ratio of aluminium to transition metal being 1 : 1 to 200 : 1 and the concentration of transition metal compound being 0À001 to 5 millimoles/litre, the solvent medium undergoing stirring to achieve dissipation of heat of polymerization which is produced. The solvent may be a hydrocarbon or halogenated hydrocarbon. The material polymerized may be an olefin, e.g. ethylene, or a mixture thereof with butadiene. The products may be used, optionally in admixture with cellulose fibrids, in the manufacture of paper-like products. Examples describe the preparation fibrids by polymerizing ethylene in heptane with catalysts comprising (2-4 and 7-10) titanium tetrachloride and polyiminoalane, (13-26) vanadyl trichloride and polyiminoalane, and (27, 29 and 30) vanadyl trichloride and ethyl aluminium sesquichloride ; ethylene in methylene chloride with catalysts comprising (32-34) vanadyl trichloride and ethyl aluminium sesquichloride; and ethylene/ butadiene in heptane with a catalyst comprising (35) triisopropyl vanadate and ethyl aluminium dichloride. |
