The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 17, 2000
Filed:
Apr. 06, 1994
Edwar S Shamshoum, Houston, TX (US);
David John Rauscher, Webster, TX (US);
Douglas Alan Burmaster, Houston, TX (US);
Fina Technology, Inc., Houston, TX (US);
Abstract
The present invention provides a catalyst system and a process for the polymerization of olefin that exhibits improved selectivity and broader molecular weight distribution in the polymer product. The catalyst system includes a conventional supported Ziegler-Natta catalyst in combination with a mixture of at least two electron donors, both having the general formula SiR.sub.m (OR').sub.4-m where R is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group and a vinyl group; R' is an alkyl group; and m is 0-3, wherein when R is an alkyl group, R may be identical with R'; when m is 0, 1 or 2, the R' groups may be identical or different; and when m is 1, 2 or 3, the R groups may be identical or different. Preferably, one electron donor is described by the formula: ##STR1## wherein R.sub.1 and R.sub.4 are both an alkyl or cycloalkyl group containing a secondary or tertiary carbon atom attached to the silicon atom, R.sub.1 and R.sub.4 being the same;; R.sub.2 and R.sub.3 are alkyl or aryl groups, R.sub.2 and R.sub.3 being the same or different; and the other electron is described by the formula: ##STR2## wherein R'.sub.1 is an alkyl or cycloalkyl group containing at least one primary, secondary or tertiary carbon atom attached to the silicon atom, R'.sub.2 and R'.sub.3 are an alkyl or aryl group, R'.sub.2 and R'.sub.3 being the same or different; and R'.sub.4 is an alkyl group with a primary carbon attached to the silicon atom, R'.sub.1 and R'.sub.4 being the same or different. This catalyst system produces polypropylene having xylene solubles of 1-7 to 5.1 wt % and a molecular weight distribution of about 10.