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).

  • Patent number: 7691956
    Abstract: 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: Grant
    Filed: June 20, 2005
    Date of Patent: April 6, 2010
    Assignee: 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
  • Patent number: 7662892
    Abstract: 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: Grant
    Filed: June 20, 2005
    Date of Patent: February 16, 2010
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Peijun Jiang, John Richard Shutt, Charles Stanley Speed, Pradeep P. Shirodkar, Robert Olds Hagerty, Larry L. Iaccino
  • Patent number: 7491776
    Abstract: 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: Grant
    Filed: June 20, 2005
    Date of Patent: February 17, 2009
    Assignee: 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
  • Publication number: 20080312375
    Abstract: 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: Application
    Filed: June 20, 2005
    Publication date: December 18, 2008
    Inventors: Robert O. Hagerty, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Peijun Jiang
  • Patent number: 7459510
    Abstract: 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: Grant
    Filed: June 20, 2005
    Date of Patent: December 2, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Zerong Lin, Pradeep P. Shirodkar
  • Publication number: 20080287615
    Abstract: 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: Application
    Filed: May 19, 2005
    Publication date: November 20, 2008
    Inventors: Robert Olds Hagerty, Kevin B. Stavens, Randall B. Laird, Michael F. McDonald, Pradeep P. Shirodkar
  • Patent number: 7449530
    Abstract: 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: Grant
    Filed: June 20, 2005
    Date of Patent: November 11, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Robert O. Hagerty, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Peijun Jiang
  • Publication number: 20080081885
    Abstract: 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: Application
    Filed: June 20, 2005
    Publication date: April 3, 2008
    Inventors: Robert O. Hagerty, Chia S. Chee, Randall B. Laird, Michael A. Risch, Pradeep P. Shirodkar, Zerong Lin, Larry L. Iaccino
  • Patent number: 7238756
    Abstract: 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: Grant
    Filed: October 15, 2003
    Date of Patent: July 3, 2007
    Assignee: Univation Technologies, LLC
    Inventors: Fred D. Ehrman, Pradeep P. Shirodkar, Mark Bradley Davis, Daniel P. Zilker, Jr., Porter C. Shannon
  • Patent number: 7129302
    Abstract: 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: Grant
    Filed: July 13, 2005
    Date of Patent: October 31, 2006
    Assignee: Univation Technologies, LLC
    Inventors: Robert Ivan Mink, Thomas Edward Nowlin, Pradeep P. Shirodkar, Gary M. Diamond, David Bruce Barry, Chunming Wang, Hitesh A. Fruitwala, Shih-May Christine Ong
  • Patent number: 7101939
    Abstract: 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: Grant
    Filed: October 11, 2002
    Date of Patent: September 5, 2006
    Assignee: 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
  • Patent number: 6995109
    Abstract: 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: Grant
    Filed: October 3, 2002
    Date of Patent: February 7, 2006
    Assignee: Univation Technologies, LLC
    Inventors: Robert I. Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Pradeep P. Shirodkar, Robert L. Santana
  • Patent number: 6964937
    Abstract: 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: Grant
    Filed: April 10, 2001
    Date of Patent: November 15, 2005
    Assignee: Univation Technologies, LLC
    Inventors: Robert Ivan Mink, Thomas Edward Nowlin, Pradeep P. Shirodkar, Gary M. Diamond, David Bruce Barry, Chunming Wang, Hitesh A. Fruitwala, Shih-May Christine Ong
  • Patent number: 6855654
    Abstract: 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: Grant
    Filed: September 16, 2002
    Date of Patent: February 15, 2005
    Assignee: ExxonMobil Oil Corporation
    Inventors: Yury V. Kissin, Robert I. Mink, Thomas E. Nowlin, Pradeep P. Shirodkar, Sandra D. Schregenberger, Grace O. Tsien
  • Publication number: 20040254308
    Abstract: 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: Application
    Filed: April 15, 2004
    Publication date: December 16, 2004
    Inventors: Kenneth G. Schurzky, Robert L. Santana, Fred D. Ehrman, Pradeep P. Shirodkar
  • Patent number: 6828395
    Abstract: 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: Grant
    Filed: October 15, 2003
    Date of Patent: December 7, 2004
    Assignee: Univation Technologies, LLC
    Inventors: Fred D. Ehrman, Pradeep P. Shirodkar, Robert Lynn Santana, Porter C. Shannon
  • Publication number: 20040242808
    Abstract: 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: Application
    Filed: March 11, 2004
    Publication date: December 2, 2004
    Inventors: Robert I Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Keith dackson, Sandra D Schregenberger, Pradeep P Shirodkar
  • Publication number: 20040198588
    Abstract: 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: Application
    Filed: April 13, 2004
    Publication date: October 7, 2004
    Inventors: Robert I. Mink, Thomas E. Nowlin, Kenneth G. Schurzky, Pradeep P. Shirodkar, Robert L. Santana
  • Patent number: 6740617
    Abstract: 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: Grant
    Filed: June 3, 2002
    Date of Patent: May 25, 2004
    Assignee: Univation Technologies, LLC
    Inventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger
  • Patent number: 6713425
    Abstract: 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: Grant
    Filed: June 3, 2002
    Date of Patent: March 30, 2004
    Assignee: Univation Technologies, LLC
    Inventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger