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US 2013/0172499 A1Published application
Process for the preparation of olefin polymers in the presence of chromium catalysts
OwnerMichael W. Lynch, Kenneth J. Kluginventors
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Abstract
A process for the polymerization of olefin carried out in the presence of a Cr-oxide supported catalyst and a cocatalyst the improvement comprising polymerizing in the presence of an effective amount of hydrogen thereby obtaining an increased catalyst activity.
Claims10
A process for polymerizing an olefin comprising the steps of:
- (i) forming an activated silica supported chromium catalyst further comprising the steps of:
- (a) preparing a homogeneous solution comprising an organic or inorganic chromium compound in a protic or aprotic polar solvent,
- (b) bringing the resulting solution from (a) into contact with the silica material to form a solid,
- (c) removing the solvent from the resulting solid formed in (b) thereby forming a chromium catalyst precursor;
- and
- (d) calcination of the chromium catalyst precursor at a temperature between 350 to 1050° C., under oxidative conditions to form the activated silica supported chromium catalyst
- (ii) polymerizing an olefin in the presence of
- (a) the silica supported chromium catalyst
- (b) a co-catalyst, and
- (c) hydrogen wherein hydrogen is present in a concentration of 0.01 to 5 mole % based upon total content of polymerization contents.
7 more elements
Dependencies are inferred from the claim text.