Procatalyst and process for the preparation of a multimodal ethylene polymer
US6225420A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1998 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Jun 9, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/901
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A procatalyst and a process for the preparation of a multimodal ethylene homopolymer or copolymer by gas-phase polymerisation is described. The procatalyst used in the process is prepared by: PA0 a) contacting the support, preferably silica with a halogenating agent, preferably ethyl aluminium dichloride to obtain a first reaction product, PA0 b) contacting the first reaction product with a compound or mixture containing hydrocarbyl and one or more of hydrocarbyloxy, monoalkylamido, dialkylamido, carboxylato and alkoxymethoxy groups linked to magnesium, thereby to obtain a second reaction product (the procatalyst precursor), and PA0 c) contacting the second reaction product with a titanium compound, preferably TiCl.sub.4. In step a) the molar ratio of the alkyl metal chloride to the surface hydroxyls of the inorganic oxide is preferably between 1:1 and 10:1. In step b) the atomic ratio of the magnesium to the chlorine of the alkyl metal chloride of step a) preferably is between 1:1.5 to 1:2.5. In step c) the atomic ratio of magnesium of step b) to titanium preferably is between 1.4 and 5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.