Phosphate supported chromium catalyst
AssigneePhillips Petroleum Company
InventorsMax P. McDaniel, Marvin M. Johnson
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Abstract
In accordance with one embodiment of this invention, a chromium catalyst supported on an aluminum phosphate-containing base is used in conjunction with a boron component either as a part of the base or as a cocatalyst. The resulting catalyst is unique both in its favorable sensitivity to molecular weight control agents such as hydrogen and in its ability to produce a fundamentally different olefin polymer. In accordance with another embodiment of this invention, the chromium is supported on a phosphate base produced using a melt of the aluminum salt.
Claims43
A catalyst system comprising
- (a) a catalyst comprising a chromium compound on a predominantly amorphous aluminum phosphate containing xerogel base;
- and
- (b) a cocatalyst comprising a boron compound selected from trihydrocarbyl boron compounds, boron alkoxides, and mixtures thereof.
A catalyst comprising a chromium compound on a predominantly amorphous aluminum phosphate base prepared by combining a melt of an aluminum salt and a source of phosphate ions and neutralizing with a base so as to cause gellation.
A method of making a catalyst system comprising
- (1) forming a catalyst by
- (a) forming a hydrogel comprising aluminum phosphate;
- (b) removing water from said hydrogel to form a xerogel;
- (c) treating said xerogel at an elevated temperature in an oxidizing atmosphere;
- (d) introducing a chromium component either by coprecipitating the chromium component with said hydrogel or adding said chromium component to said hydrogel or adding said chromium component anhydrously to said xerogel prior to said treating in said oxidizing atmosphere;
- and
- (2) combining said catalyst with a cocatalyst comprising a boron compound selected from trihydrocarbyl boron compounds, boron alkoxides, and mixtures thereof.
A method of forming a catalyst comprising combining a melt of an aluminum salt with a source of phosphate ions, neutralizing the resulting combination to produce aluminum phosphate, removing water to produce a xerogel and activating the resulting xerogel, and wherein a chromium component having chromium in or convertible to the hexavalent state is introduced prior to said activation.
Dependencies are inferred from the claim text.