W. R. Grace Co.-conn.

W. R. Grace Co.

Rimantas Glemza

Dean Alexander Denton

Keng-Yu Shih

Robert B DeWolf, Ii

John Lawrence Warthen

Yves O Parent

The present invention is directed to a novel one-step method for forming a supported catalyst complex of high activity by substantially simultaneously contacting a bidentate or tridentate ligand forming compound, a transition metal compound and a chromium immobilized Lewis acid support-agglomerate. The catalyst can be formed prior to polymerization of olefins or within the polymerization reaction zone.

Chromium support-agglomerate-transition metal polymerization catalysts and processes utilizing same

The present invention is directed to a coordinating catalyst system comprising at least one pre-catalyst selected from late transition metal bidentate or tridentate ligand containing compounds, at least one support-agglomerate having chromium immobilized thereto (e.g., spray dried silica/clay agglomerate), and optionally at least one organometallic compound in controlled amounts, and methods for preparing the same. The resulting catalyst system exhibits enhanced activity for polymerizing olefins and yields polymer products having very good morphology.

Coordination catalyst systems employing chromium support-agglomerate and method of their preparation

A chromium containing catalyst wherein the chromium atom is in one of its higher valence states and is immobilized to a support-agglomerate composed of at least one inorganic oxide component and at least one ion-containing layered component.

Heterogeneous chromium catalysts and processes of polymerization of olefins using same

High melt index polyolefins have been obtained with chromium silica catalysts under conventional polymerization conditions without the use of titanium or other additives. The useful chromium silica catalysts have a pore volume in the range of 1.9-2.9 cc/g and a narrow pore size distribution. The silica is a silica gel preferably obtained from a low solids, rapid gelation process.

High pore volume polyolefin catalyst

The present invention encompasses a monolithic multi-component composite polyolefin catalyst particle comprising at least two distinct supported catalyst components wherein each catalyst component is capable of producing a resin having a melt index different from at least one other catalyst component under constant reaction conditions. Methods of producing and using the multi-component catalyst are disclosed.

Multi-component polyolefin catalysts

Aluminum phosphate compositions are provided which are characterized simultaneously by high porosity and phosphorous-to-aluminum ratios of approximately 1.0. The high porosity of these compositions is a function of high pore volume coupled with low surface area, resulting in high average pore diameter. These materials have excellent properties as catalysts and catalyst supports. Methods of making the compositions are also provided.

High pore volume and pore diameter aluminum phosphate and method of

Aluminum phosphate compositions are provided which are characterized simultaneously by high porosity and phosphorous-to-aluminum ratios of approximately 1.0. The high porosity of these compositions is a function of high pore volume coupled with low surface area, resulting in high average pore diameter. These materials have excellent properties as catalysts and catalyst supports.

High pore volume and pore diameter aluminum phosphate

Dentifrice compositions containing a hydrous silica gel having a water content of from about 20 to about 60 weight percent are disclosed. The abrasiveness of the gel is increased by contacting the gel with an alkaline medium to provide a gel pH of about 6 to about 10 and/or preparing the gel by drying and grinding a silica hydrogel that has been washed with an aqueous acidic solution having a temperature of from about 80.degree. to about 100.degree. F.

Methods of preparing hydrous silica gels

Hydrous silica gel containing dentifrice

A composition for polishing silicon and germanium comprises a synthetic amorphous silica polishing agent and a suspending agent selected from the group consisting of water-soluble carboxypolymethylene gums and xanthum gums. The composition may be used for polishing in the form of an aqueous alkaline slurry.

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Baltimore, MD, United States of America

Rimantas Glemza