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).

  • Publication number: 20040048736
    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: Application
    Filed: May 29, 2003
    Publication date: March 11, 2004
    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: 6569963
    Abstract: A process for controlling the MWD of a broad or bimodal resin in a single fluid bed reactor using a mixed catalyst composition containing a bimetallic catalyst and a make-up catalyst of at least one metallic component of the bimetallic catalyst. The bimetallic catalyst, which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought. The mixed catalyst compostion may be fed into the reactor as a mixture or through separate catalyst ports of the reactor.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: May 27, 2003
    Assignee: ExxonMobil Oil Corporation
    Inventors: Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Publication number: 20030054946
    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: Application
    Filed: June 3, 2002
    Publication date: March 20, 2003
    Inventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger
  • Publication number: 20030032550
    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: Application
    Filed: June 3, 2002
    Publication date: February 13, 2003
    Inventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger
  • Publication number: 20030017938
    Abstract: The invention relates to a process for uniformly dispersing a transition metal metallocene complex on a carrier comprising
    Type: Application
    Filed: September 16, 2002
    Publication date: January 23, 2003
    Inventors: Yury V. Kissin, Robert I. Mink, Thomas E. Nowlin, Pradeep P. Shirodkar, Sandra D. Schregenberger, Grace O. Tsien
  • Patent number: 6486089
    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.; (3) providing a volume of a solution comprising metallocene and alumoxane wherein the volume of solution is less than that required to form a slurry of the silica, wherein the concentration of alumoxane, expressed as Al weight percent, is 5 to 20; (4) contacting the silica slurry (2) with said volume of said solution (3) and allowing the solution to impregnate the pores of silica and, to disperse the metallocene in and on the carrier; (5) evaporating the solvents from the contacted and impregnated silica to recover dry free-flowing catalyst particles.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: November 26, 2002
    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: 20020173601
    Abstract: A process for controlling the MWD of a broad or bimodal resin in a single fluid bed reactor using a mixed catalyst composition containing a bimetallic catalyst and a make-up catalyst of at least one metallic component of the bimetallic catalyst. The bimetallic catalyst, which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought. The mixed catalyst compostion may be fed into the reactor as a mixture or through separate catalyst ports of the reactor.
    Type: Application
    Filed: May 9, 2002
    Publication date: November 21, 2002
    Inventors: Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Publication number: 20020160908
    Abstract: A catalyst composition for the polymerization of one or more 1-olefins (e.g., ethylene) comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. In another embodiment, the transition metal catalyst precursor is bimetallic and contains a non-metallocene transition metal catalyst component. When a bimetallic catalyst precursor is used, the resin product exhibits improved properties, and has a bimodal molecular weight distribution, long chain branching (LCB), and good bubble stability.
    Type: Application
    Filed: April 1, 2002
    Publication date: October 31, 2002
    Inventors: Robert Ivan Mink, Thomas Edward Nowlin, Sandra Denise Schregenberger, Pradeep P. Shirodkar, Kenneth George Schurzky
  • Publication number: 20020156206
    Abstract: A make-up catalyst of at least one metallic component of a bimetallic catalyst component is used in conjunction with a bimetallic catalyst to control the proportion of weight fractions in broad or bimodal molecular weight distribution olefin resin product. The bimetallic catalyst produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by te bimetallic catalyst is sought.
    Type: Application
    Filed: April 15, 2002
    Publication date: October 24, 2002
    Inventors: Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Patent number: 6458911
    Abstract: A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.925 g/cc, a flow index (I21) no higher than about 15 g/10 min., a melt flow ratio (MFR) of at least about 65, and a dynamic elasticity at 0.1 rad./sec. of no higher than about 0.7 at a corresponding complex viscosity at 0.1 rad./sec. no higher than about 14×105 poises. The ethylene polymer is a bimodal of relatively high molecular weight (HMW) and low molecular weight (LMW) ethylene polymers.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: October 1, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventors: S. Christine Ong, Sandra D. Schregenberger, Pradeep P. Shirodkar
  • Patent number: 6458910
    Abstract: Blown films of linear low density polyethylene are produced by a high stalk process comprising extruding the linear low density polyethylene through an annular die to form an extruded tube of molten material, cooling the extruded tube while drawing the tube so cooled, to maintain the tube diameter identical to that of the annular die and expanding the tube or bubble to attenuate the walls thereof by introducing a gas to the interior of the tube or bubble. The resulting films are characterized by superior impact strength and MD tear resistance.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: October 1, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventors: Vaseem Firdaus, Pradeep P. Shirodkar
  • Patent number: 6420298
    Abstract: A catalyst composition for the polymerization of one or more 1-olefins (e.g., ethylene) comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. In another embodiment, the transition metal catalyst precursor is bimetallic and contains a non-metallocene transition metal catalyst component. When a bimetallic catalyst precursor is used, the resin product exhibits improved properties, and has a bimodal molecular weight distribution, long chain branching (LCB), and good bubble stability.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: July 16, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventors: Robert I. Mink, Thomas E. Nowlin, Sandra D. Schregenberger, Kenneth G. Schurzky, Pradeep P. Shirodkar
  • Patent number: 6417130
    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 trialkylaluminum compound, and methylalumoxane.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: July 9, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventors: Robert I. Mink, Yury V. Kissin, Thomas E. Nowlin, Pradeep P. Shirodkar, Grace O. Tsien, Sandra D. Schregenberger
  • Patent number: 6417289
    Abstract: LLDPE films with superior impact strength are obtained by blowing lightly crosslinked LLDPE resins under film extrusion conditions typically used for blowing HDPE film.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: July 9, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventor: Pradeep P. Shirodkar
  • Patent number: 6410474
    Abstract: A make-up catalyst of at least one metallic component of a bimetallic catalyst component is used in conjunction with a bimetallic catalyst to control the proportion of weight fractions in broad or bimodal molecular weight distribution olefin resin product. The bimetallic catalyst which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: June 25, 2002
    Assignee: ExxonMobil Oil Corporation
    Inventors: Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Publication number: 20020042472
    Abstract: A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.935 g/cc, a flow index (I21) no higher than about 15 g/10 min., a melt flow ratio (MFR) of at least about 65, and a dynamic elasticity at 0.1 rad./sec. of no higher than about 0.7 at a corresponding complex viscosity at 0.1 rad./sec. no higher than about 14E5, i.e., about 14×105 poises.
    Type: Application
    Filed: October 2, 2001
    Publication date: April 11, 2002
    Inventors: S. Christine Ong, Sandra D. Schregenberger, Pradeep P. Shirodkar
  • Patent number: 6316546
    Abstract: A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.925 g/cc, a flow index (I21) no highier than about 15 g/10 min., a melt flow ratio (MFR) of at least about 65, and a dynamic elasticity at 0.1 rad./sec. of no higher than about 0.7 at a corresponding complex viscosity at 0.1 rad./sec. no highier than about 14E5, i.e., about 14×105 poises. The ethylene polymer is a bimodal blend of relatively high molecular weight (HMW) and low molecular weight (LMW) ethylene polymers.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: November 13, 2001
    Assignee: ExxonMobil Oil Corporation
    Inventors: S. Christine Ong, Sandra D. Schregenberger, Pradeep P. Shirodkar
  • Patent number: 5882750
    Abstract: Single reactor bimodal MWD high molecular weight polyethylene film resin has improved bubble stability. The bimodal molecular weight distribution resin has low resin elasticity. Preferably the resin is made catalytically in one reactor. The preferred catalyst appears to control the properties of bubble stability and elasticity.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: March 16, 1999
    Assignee: Mobil Oil Corporation
    Inventors: Robert I. Mink, Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Patent number: 5840244
    Abstract: Blown films of linear low density polyethylene are produced by a high stalk process comprising extruding the linear low density polyethylene through an annular die to form an extruded tube of molten material, cooling the extruded tube while drawing the tube so cooled, to maintain the tube diameter identical to that of the annular die and expanding the tube or bubble to attenuate the walls thereof by introducing a gas to the interior of the tube or bubble. The resulting films are characterized by superior impact strength and MD tear resistance.
    Type: Grant
    Filed: January 14, 1992
    Date of Patent: November 24, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Vaseem Firdaus, Pradeep P. Shirodkar
  • Patent number: 5756203
    Abstract: LLDPE films with superior impact strength are obtained by blowing lightly crosslinked LLDPE resins under film extrusion conditions typically used for blowing HDPE film.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: May 26, 1998
    Assignee: Mobil Oil Corporation
    Inventor: Pradeep P. Shirodkar