Polymerization catalysts and polymers

• US 9,376,511 B2
• Filed: 03/13/2013
• Issued: 06/28/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Chevron Phillips Chemical Company LP (Chevron Corp.)
• Original Assignee: Chevron Phillips Chemical Company LP (Chevron Corp.)
• Inventors: McDaniel, Max P., Collins, Kathy S., Schwerdtfeger, Eric D., Solenberger, Alan L.
• Primary Examiner(s): Neckel, Alexa
• Assistant Examiner(s): Eng, Elizabeth
• Application Number:
  US13/799,516
• Publication Number:
  US 20140275457A1
• Time in Patent Office: 1,203 Days
• Field of Search: 502/256, 526/90, 526/106
• US Class Current: 1/1
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/025 Metal oxides
• CPC Class Codes: C08F 4/22 of chromium, molybdenum or tungsten
• CPC Class Codes: C08F 4/24 Oxides

Abstract

A method comprising contacting a support material with a transition metal compound to produce a mixture; thermally treating the mixture in the presence of oxygen at a temperature in a range of from about 100° C. to about 500° C. for a period of from about 1 hour to about 10 hours, wherein at least a portion of the transition metal sublimes onto the support material to produce a support material comprising a dispersed transition metal; and thermally treating the support material comprising the dispersed transition metal in an oxidizing atmosphere at a temperature in a range of from about 550° C. to about 900° C. for a period of from about 1 hour to about 10 hours to produce a polymerization catalyst.

Claims

1. A method comprising:

subjecting a support material to a first thermal treatment at a temperature in a range of from about 550°

C. to about 900°

C. for a period of from about 1 hour to about 10 hours to produce a thermally-treated support material;

cooling the thermally-treated support material to a temperature in the range of from about 100°

C. to about 150°

C.;

contacting the thermally-treated support material with chromium (III) acetylacetonate, which is in powder or crystal form, to produce a mixture; and

subjecting the mixture in the presence of oxygen to a second thermal treatment at a temperature in a range of from about 100°

C. to about 500°

C. for a period of from about 1 hour to about 10 hours, wherein at least a portion of the chromium(III) acetylacetonate sublimes onto the support material to produce a polymerization catalyst and wherein the second thermal treatment occurs at a temperature that is less than the first thermal treatment.

2. The method of claim 1 wherein the support material comprises silica, alumina, silica-titania, aluminophosphate, zirconia, titania, or combinations thereof.

3. The method of claim 1 wherein support material comprises silica-titania.

4. The method of claim 1 wherein chromium is present in the polymerization catalyst in an amount of from about 0.5 wt. % to about 2 wt. % based on the weight of the support material.

5. The method of claim 1 wherein a percentage conversion of chromium in the (+3) oxidation state to chromium in the (+6) oxidation state for the polymerization catalyst is from about 20% to about 100% at a temperature range of from about 200°

C. to about 600°

C.

6. The method of claim 1 further comprising producing a polymer by contacting the polymerization catalyst with an olefin monomer and recovering the polymer.

7. The method of claim 6 wherein the polymer has a melt index that is from about 0.5 g/10 min to about 5 g/10 min.

8. The method of claim 6 wherein the polymer has a high load melt index that is from about 50 g/10 min to about 200 g/10 min.

9. The method of claim 6 wherein the polymer comprises polyethylene.

10. The method of claim 1 wherein the support material has an average particle size of from about 25 μ

m to about 500 μ

m.