Patent ES-267374-A1 (ES)
Title: Catalysts having an improved activity in the stereospecific polymerization of alpha-olefins and process for preparing same
IPC: C08F4/68
Filed: 1961-05-12
Abstract: Titanium trichloride and vanadium trichloride may be purified by forming complexes thereof with heterocyclic nitrogen containing bases, e.g. pyridine, and subsequently thermally decomposing the complexes. The complexes may be prepared by adding the halide to the base and heating to the boiling point to effect complete solubilization, and the complexes subsequently precipitated by cooling, optionally together with the addition of a non-solvent, e.g. heptane. The complexes may be recrystallized from solvents, e.g. pyridine or chloroform. The complexes may be decomposed by heating at 200 to 400 DEG C. and the resulting halides may be used in polymerization catalysts. The preparations and decompositions of the complexes TiCl3.3 Py and VCl3.3 Py where Py represents pyridine are described.ALSO:A polymerization catalyst obtained by contacting an organometallic compound of a metal of Group I, II or III of the Mendel<\>eeff Periodic Table and a transition metal halide in which the metal has a valency lower than its maximum, is characterized in that the transition metal halide is obtained in crystalline form by thermal decomposition of the complex compound formed by dissolving the transition metal halide in an organic heterocyclic nitrogen containing base. Specified bases are pyridine, quinoline and isoquinoline. The transition metal halide may be titanium trichloride or vanadium trichloride. The transition metal halide may be prepared in supported form suitable for fluidized bed processes by impregnating the support with a solution of the complex, precipitating the complex on the support by addition of a non-solvent, e.g. hexane, heptane, benzene, toluene or ethyl benzene, or forming the complex in situ on the support, and subsequently decomposing the complex. The supports may be sulphates, chlorides, carbonates or oxides of alkali or alkaline earth metals, alumina, silica gel or carbon. The complexes may be purified by recrystallization from solvents, e.g. pyridine or chloroform. The catalysts may be used for the polymerization of olefins and examples describe the polymerization of propylene in the presence of heptane and catalysts obtained by contacting triethyl aluminium with (1) titanium trichloride and (2) vanadium trichloride prepared from pyridine complexes thereof, and in the presence of catalysts obtained by contacting triethyl aluminium with titanium trichloride prepared from a pyridine complex thereof and supported on (3 and 4) calcium chloride and (5) sodium chloride and the polymerization of butene-1 in the presence of a catalyst prepared by contacting (6) triethyl aluminium and titanium chloride from a pyridine complex thereof.ALSO:Complexes of titanium trichloride and vanadium trichloride with heterocyclic nitrogen containing bases, e.g. pyridine, may be prepared by adding the halide to the base, heating to effect solubilisation, and cooling when the complex is precipitated. The complexes may be purified by recrystallisation, e.g. from pyridine or chloroform. Examples describe the preparation of TiCl3.3Py and VCl3.3Py where Py represents pyridine.