GB1281843A - Process for preparing ethylene polymers - Google Patents

Abstract

1281843 Ethylene polymers SOC ITALIANA RESINE SpA 23 Feb 1970 [28 Feb 1969] 8659/70 Heading C3P Polymers of ethylene and copolymers thereof with other alpha-olefins are prepared by using catalysts comprising an organometallic compound of a metal of Groups IIb or IIIb of the Periodic System, a compound of a metal of Group IVa at its maximum valence and a compound of a metal of Groups IVa and Va at a valence lower than maximum, which have been prepared by reducing a compound of the metal of Groups IVa or Va, in which the metal is at its maximum valence, with a metal, organometallic hydride or compound of an element of groups Ia, IIb or IIIb, the quantity of said reducing agent being a 10 to 20% excess of the necessary quantity for obtaining the compound of the metal of groups IVa or Va at the desired valence in a medium of saturated aliphatic hydrocarbons or aromatic hydrocarbons at a temperature between 100‹ and 200‹ C. for a period of 0À5 to 5À0 hours, mixing the suspension so obtained with an organometallic compound of a metal of groups IIb or IIIb and with a compound of the metal of group IVa at its maximum valence, in quantities such that the atomic ratio of the metal at a valence below the maximum valence and the metal of Group IVa at its maximum valence ranges between 0À05 : 1 and 2À0 : 1, the atomic ratio of the metal of Groups IIb or IIIb and the metal at a valence below the maximum valence ranges between 1 : 1 and 20 : 1, mixing being effected at a temperature of 0‹ to 80‹ C. in the presence of a saturated hydrocarbon or aromatic hydrocarbon solvent in quantities such that the concentration of catalyst salts in the final product amounts to 1 to 10 grams to 100 ml. of the hydrocarbon solvent. In examples, ethylene is polymerized using a catalyst comprising Al 2 (C 2 H 5 ) 3 Cl 3 , TiCl 4 and the reaction product of TiCl 4 or VOCl 3 with Al 2 (C 2 H 5 ) 3 Cl 3 .