Catalyst for high temperature olefin polymerization

摘要

An olefin polymerization catalyst is prepared by (a) in a diluent, combining a diorganomagnesium compound with less than 2 molar equivalents of a first source of chloride to produce a “chloride deficient” magnesium chloride support; (b) without isolating any solids, adding a second source of chloride which reduces the amount of soluble un-reacted diorganomagnesium compound present; (c) without isolating any solids present, adding a tetravalent titanium species and; (d) adding an activator. The catalyst is active for solution polymerization of olefins.

主权项

1. A process to prepare an olefin polymerization catalyst, said process comprising:
(a) in a diluent, combining a diorganomagnesium compound of the formula MgRaRb with a first source of chloride to give a first product mixture, wherein the molar ratio of chloride in said first source of chloride to magnesium Mg is from 1.5:1 to 1.95:1 and where Ra and Rb are individually C1 to C8 hydrocarbyl groups; (b) without isolating any solids present in said first product mixture, combining said first product mixture with a second source of chloride to give a second product mixture, wherein the molar ratio of chloride in said second source of chloride to total magnesium Mg is from 0.01:1 to 0.7:1; wherein the total molar ratio of chloride from said first source of chloride and from said second source of chloride to magnesium Mg does not exceed a ratio of 2.2:1; (c) without isolating any solids present in said second product mixture, combining said second product mixture with a titanium species to give a third product mixture, said titanium species having the formula TiCln(OR)m, wherein n is from 2 to 4, n+m=4 and OR is selected from an alkoxy group, an aryloxy group, or mixtures thereof; and (d) i) combining said third product mixture with an activator; or
ii) combining solids isolated from said third product mixture with an activator; wherein the first source of chloride and the second source of chloride are each chosen from an organic chloride compound or HCl.