Patents by Inventor Pradeep P. Shirodkar
Pradeep P. Shirodkar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7691956Abstract: This invention is directed to processes of making polymer in the presence of a hydrofluorocarbon or perfluorocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and to the recovery of the hydrofluorocarbon and other hydrocarbons such as hydrocarbons for reuse in the process or hydrocarbon by-products from the polymerization process. The invention is particularly beneficial in the production of ethylene based polymers using bulky ligand metallocene-type catalyst systems.Type: GrantFiled: June 20, 2005Date of Patent: April 6, 2010Assignee: ExxonMobil Chemical Patents Inc.Inventors: Robert O. Hagerty, Chia S. Chee, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Zerong Lin, Larry L. Iaccino
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Patent number: 7662892Abstract: This invention relates to a continuous process to prepare olefin impact copolymers comprising producing a semi-crystalline olefin polymer in a first reactor and then transferring the reactor contents to a second reactor where a low crystallinity olefin polymer is produced in the presence of the semi-crystalline polymer, where a fluorinated hydrocarbon is present in the polymerization medium of the first reactor, the second reactor or both reactors.Type: GrantFiled: June 20, 2005Date of Patent: February 16, 2010Assignee: ExxonMobil Chemical Patents Inc.Inventors: Peijun Jiang, John Richard Shutt, Charles Stanley Speed, Pradeep P. Shirodkar, Robert Olds Hagerty, Larry L. Iaccino
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Patent number: 7491776Abstract: This invention is directed to processes of making polymer in the presence of a hydrofluorocarbon or perfluorocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and provide polymer products that can be manufactured to relatively low densities. The invention is particularly beneficial in the production of ethylene based polymers using chromium catalyst systems.Type: GrantFiled: June 20, 2005Date of Patent: February 17, 2009Assignee: ExxonMobil Chemical Patents Inc.Inventors: Robert O. Hagerty, Chia S. Chee, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Zerong Lin, Larry L. Iaccino
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Publication number: 20080312375Abstract: This invention is directed to processes of making polymer in the presence of a fluorinated hydrocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and allows for the recovery of the fluorinated hydrocarbon and other hydrocarbons such as hydrocarbons for re-use in the process or hydrocarbon by-products from the polymerization process. The invention is particularly beneficial in the production of propylene polymers and copolymes using bulky ligand metallocene-type catalyst systems.Type: ApplicationFiled: June 20, 2005Publication date: December 18, 2008Inventors: Robert O. Hagerty, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Peijun Jiang
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Patent number: 7459510Abstract: This invention relates to a process to polymerize olefins comprising contacting, in a reactor, a pyridyl-di-imine compound and an activator with one or more olefin monomer(s) in the presence of a fluorinated hydrocarbon.Type: GrantFiled: June 20, 2005Date of Patent: December 2, 2008Assignee: ExxonMobil Chemical Patents Inc.Inventors: Zerong Lin, Pradeep P. Shirodkar
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Publication number: 20080287615Abstract: The present invention relates to a gas phase process for polymerizing one or more hydrocarbon monomer(s) in the presence of a catalyst system and a fluorinated hydrocarbon, where the fluorinated hydrocarbon is present at a partial pressure of 6.9 to 348 kPa in the reactor and the reactor temperature is from 30 to 120° C.Type: ApplicationFiled: May 19, 2005Publication date: November 20, 2008Inventors: Robert Olds Hagerty, Kevin B. Stavens, Randall B. Laird, Michael F. McDonald, Pradeep P. Shirodkar
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Patent number: 7449530Abstract: This invention is directed to processes of making polymer in the presence of a fluorinated hydrocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and allows for the recovery of the fluorinated hydrocarbon and other hydrocarbons such as hydrocarbons for re-use in the process or hydrocarbon by-products from the polymerization process. The invention is particularly beneficial in the production of propylene-ethylene based copolymers using Ziegler-Natta catalyst systems.Type: GrantFiled: June 20, 2005Date of Patent: November 11, 2008Assignee: ExxonMobil Chemical Patents Inc.Inventors: Robert O. Hagerty, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Peijun Jiang
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Publication number: 20080081885Abstract: This invention is directed to processes of making polymer in the presence of a hydrofluorocarbon or perfluorocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and to the recovery of the hydrofluorocarbon and other hydrocarbons such as hydrocarbons for reuse in the process or hydrocarbon by-products from the polymerization process. The invention is particularly beneficial in the production of ethylene based polymers using bulky ligand metallocene-type catalyst systems.Type: ApplicationFiled: June 20, 2005Publication date: April 3, 2008Inventors: Robert O. Hagerty, Chia S. Chee, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Zerong Lin, Larry L. Iaccino
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Patent number: 7238756Abstract: Methods of controlling the flow index and/or molecular weight split of a polymer composition are disclosed. The method of producing a polymer composition in one embodiment comprises incorporating a high molecular weight polymer into a low molecular weight polymer to form the polymer composition in a single polymerization reactor in the presence of polymerizable monomers, a bimetallic catalyst composition and at least one control agent; wherein the control agent is added in an amount sufficient to control the level of incorporation of the high molecular weight polymer, the level of low molecular weight polymer, or both. Examples of control agents include alcohols, ethers, amines and oxygen.Type: GrantFiled: October 15, 2003Date of Patent: July 3, 2007Assignee: Univation Technologies, LLCInventors: Fred D. Ehrman, Pradeep P. Shirodkar, Mark Bradley Davis, Daniel P. Zilker, Jr., Porter C. Shannon
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Patent number: 7129302Abstract: Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component, This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.Type: GrantFiled: July 13, 2005Date of Patent: October 31, 2006Assignee: Univation Technologies, LLCInventors: Robert Ivan Mink, Thomas Edward Nowlin, Pradeep P. Shirodkar, Gary M. Diamond, David Bruce Barry, Chunming Wang, Hitesh A. Fruitwala, Shih-May Christine Ong
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Patent number: 7101939Abstract: An ethylene/?-olefin copolymer comprising a component produced by a non-single-site polymerization catalyst and a component produced by a single-site polymerization catalyst, its preparation and use are described. The copolymer has an ?-olefin content of 5 to 20 percent by weight and shows at least two CRYSTAF peak temperatures differing by at least 15° C. and/or at least two DSC melting peak temperatures differing by at least 15° C.Type: GrantFiled: October 11, 2002Date of Patent: September 5, 2006Assignee: ExxonMobil Chemical Patents Inc.Inventors: Thomas Edward Nowlin, Pradeep P. Shirodkar, Robert Ivan Mink, Gary M. Diamond, Jill Helaine Paul, Lawrence T. Kale, Keith Dackson
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Patent number: 6995109Abstract: Methods of preparing bimetallic catalysts are disclosed. The methods include the steps of providing a supported non-metallocene catalyst, contacting a slurry of the supported non-metallocene catalyst in a non-polar hydrocarbon with a solution of a metallocene compound and an alumoxane, and drying the contact product to obtain a supported bimetallic catalyst. The supported non-metallocene catalyst is prepared by dehydrating a particulate support material at a temperature of greater than 600° C., preparing a slurry of the dehydrated support in a non-polar hydrocarbon, contacting the slurry with an organomagnesium compound and an alcohol, contacting the resulting slurry with a non-metallocene compound of a Group 4 or Group 5 transition metal, and drying the contact product to obtain a supported non-metallocene catalyst as a free-flowing powder. The bimetallic catalysts show increased activity relative to catalysts prepared using support materials dehydrated at lower temperatures.Type: GrantFiled: October 3, 2002Date of Patent: February 7, 2006Assignee: Univation Technologies, LLCInventors: Robert I. Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Pradeep P. Shirodkar, Robert L. Santana
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Patent number: 6964937Abstract: Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component. This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.Type: GrantFiled: April 10, 2001Date of Patent: November 15, 2005Assignee: Univation Technologies, LLCInventors: Robert Ivan Mink, Thomas Edward Nowlin, Pradeep P. Shirodkar, Gary M. Diamond, David Bruce Barry, Chunming Wang, Hitesh A. Fruitwala, Shih-May Christine Ong
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Patent number: 6855654Abstract: The invention relates to a process for uniformly dispersing a transition metal metallocene complex on a carrier comprising (1) providing silica which is porous and has a particle size of 1 to 250 microns, having pores which have an average diameter of 50 to 500 Angstroms and having a pore volume of 0.5 to 5.0 cc/g; (2) slurrying the silica in an aliphatic solvent having a boiling point less than 110° C.Type: GrantFiled: September 16, 2002Date of Patent: February 15, 2005Assignee: ExxonMobil Oil CorporationInventors: Yury V. Kissin, Robert I. Mink, Thomas E. Nowlin, Pradeep P. Shirodkar, Sandra D. Schregenberger, Grace O. Tsien
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Publication number: 20040254308Abstract: Methods of monitoring and controlling polymerization reactions are disclosed. The ratio of concentrations of two reactor components are determined in a gas stream of a reactor to obtain a leading indicator function L. The value of L or a function of L, such as a rescaled value or a reciprocal, is compared to a target value, and at least one reactor parameter is adjusted in response to a deviation between L or the function of L and the target value. Monitoring of the leading indicator permits rapid diagnosis of reactor problems, and rapid adjustments of reactor parameters, compared to laboratory analysis of samples of polymer properties.Type: ApplicationFiled: April 15, 2004Publication date: December 16, 2004Inventors: Kenneth G. Schurzky, Robert L. Santana, Fred D. Ehrman, Pradeep P. Shirodkar
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Patent number: 6828395Abstract: Methods of controlling rheological properties of polymer compositions comprising at least one high molecular weight polymer and one low molecular weight polymer are disclosed. The polymer compositions are produced by polymerizing monomers in a single reactor using a bimetallic catalyst composition. A control agent such as, for example, an alcohol, ether, oxygen or amine is added to the reactor to control the rheological properties of the reactor. The polymerization takes place in the presence of rheological-altering compounds such as alkanes and aluminum alkyls. The control agents are added in an amount sufficient to counter the influences of the rheological-altering compounds.Type: GrantFiled: October 15, 2003Date of Patent: December 7, 2004Assignee: Univation Technologies, LLCInventors: Fred D. Ehrman, Pradeep P. Shirodkar, Robert Lynn Santana, Porter C. Shannon
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Publication number: 20040242808Abstract: A method is disclosed for preparing broad or bimodal molecular weight distribution polyolefins having a targeted property, such as, flow index, melt flow ratio, or weight fractions of higher or lower molecular weight components. The method uses a bimetallic catalyst containing a metallocene component and a non-metallocene component, and the activities of the metallocene and non-metallocene portions are controlled by adjusting the ratio of organoaluminum and modified methylaluminoxane cocatalyst. The method allows for monitoring and adjustment of polyolefin properties on a real-time basis, as the polyolefin is forming.Type: ApplicationFiled: March 11, 2004Publication date: December 2, 2004Inventors: Robert I Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Keith dackson, Sandra D Schregenberger, Pradeep P Shirodkar
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Publication number: 20040198588Abstract: Methods of preparing bimetallic catalysts are disclosed. The methods include the steps of providing a supported non-metallocene catalyst, contacting a slurry of the supported non-metallocene catalyst in a non-polar hydrocarbon with a solution of a metallocene compound and an alumoxane, and drying the contact product to obtain a supported bimetallic catalyst. The supported non-metallocene catalyst is prepared by dehydrating a particulate support material at a temperature of greater than 600° C., preparing a slurry of the dehydrated support in a non-polar hydrocarbon, contacting the slurry with an organomagnesium compound and an alcohol, contacting the resulting slurry with a non-metallocene compound of a Group 4 or Group 5 transition metal, and drying the contact product to obtain a supported non-metallocene catalyst as a free-flowing powder. The bimetallic catalysts show increased activity relative to catalysts prepared using support materials dehydrated at lower temperatures.Type: ApplicationFiled: April 13, 2004Publication date: October 7, 2004Inventors: Robert I. Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Pradeep P. Shirodkar, Robert L. Santana
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Patent number: 6740617Abstract: A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkyl-aluminum compound, and methylalumoxane.Type: GrantFiled: June 3, 2002Date of Patent: May 25, 2004Assignee: Univation Technologies, LLCInventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger
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Patent number: 6713425Abstract: A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkyl-aluminum compound, and methylalumoxane.Type: GrantFiled: June 3, 2002Date of Patent: March 30, 2004Assignee: Univation Technologies, LLCInventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger