Magnesium-titanium-hafnium for high temperature polymerization
AssigneeNOVA Chemicals (International) S.A.
InventorsQinyan Wang, Peter Zoricak, Joanna Ronne Newman
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Abstract
A magnesium titanium olefin polymerization procatalyst is prepared by A) reacting a diorganomagnesium compound with a source of active chlorine, (with the proviso that the amount of chlorine is insufficient to completely convert the diorganomagnesium to magnesium dichloride); then B) removing unreacted diorganomagnesium from the reaction product; then C) adding a tetravalent hafnium species to the washed MgCl2 support; then D) depositing a tetravalent titanium species on the supported Hf. This procatalyst is highly active for the solution polymerization of olefins when combined with a cocatalyst.
Claims8
A process to prepare an olefin polymerization procatalyst, said process comprising:
- Step a) forming a solid product by reacting:
- i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C1 to C8 hydrocarbyl groups, with
- ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to the total moles of Mg is from 1.55 to 1.90/1;
- followed by:
- Step b) adding a tetravalent hafnium species which is soluble in said liquid hydrocarbon in an amount such that the Hf/Mg molar ratio is from 1/10 to 1/100;
- followed by:
- Step c) adding a tetravalent titanium chloride species of the formula:
- Ti Cln(OR)m wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof.
A process to prepare an olefin polymerization procatalyst, said process comprising:
- Step a) forming an in-situ magnesium chloride support by reacting in a liquid hydrocarbon:
- i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C1 to C8 hydrocarbyl groups, with
- ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to the total moles of Mg is from 1.55 to 1.90/1;
- followed by:
- Step b) adding a tetravalent hafnium species which is soluble in said liquid hydrocarbon in an amount such that the Hf/Mg molar ratio is from 1/10 to 1/100;
- followed by:
- Step c) adding a tetravalent titanium chloride species of the formula:
- Ti Cln(OR)m wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof.
A process to prepare an olefin polymerization procatalyst, said process comprising:
- Step a) forming an in-situ magnesium chloride support by reacting in a liquid hydrocarbon:
- i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C1 to C8 hydrocarbyl groups, with
- ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to the total moles of Mg is 2;
- followed by:
- Step b) adding a tetravalent hafnium species which is soluble in said liquid hydrocarbon in an amount such that the Hf/Mg molar ratio is from 1/10 to 1/100;
- followed by:
- Step c) adding a tetravalent titanium chloride species of the formula:
- Ti Cln(OR)m wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof;
- followed by
- Step d) adding an electron donor;
- followed by
- Step e) adding a second increment of tetravalent titanium chloride.
Dependencies are inferred from the claim text.