Patents by Inventor Grace O. Tsien

Grace O. Tsien 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: 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
  • 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
  • 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: 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: 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: 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
  • 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: 5614456
    Abstract: The interaction of silica, previously calcined at 600.degree. C., with dibutylmagnesium (DBM), 1-butanol and titanium tetrachloride and a solution of methylalumoxane (MAO) and (BuCp).sub.2 ZrCl.sub.2 provides a catalyst that, in the absence of a trialkylaluminum (AlR.sub.3) cocatalyst, produces polyethylene with a bimodal MWD.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: March 25, 1997
    Assignee: Mobil Oil Corporation
    Inventors: Robert I. Mink, Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Patent number: 5539076
    Abstract: Resins which are in situ catalytically produced blends of broad bimodal molecular weight distribution ethylene resin are produced. The resins of the invention are characterized by a blend of low molecular weight component and high molecular weight component with HMW component weight fraction which is greater than 0 (zero). Generally, the LMW/HMW weight fraction can be controlled within a very broad range. The resin has a molecular weight distribution, which is characterized as MFR or Mw/Mn. The bimodal molecular weight resins can be processed into films on existing equipment, and exhibit good processability in blown film production and provide film product of excellent FQR. The resin of the invention exhibits reduced tendency towards die-lip buildup and smoking in on-line operations.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: July 23, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Thomas E. Nowlin, Sandra D. Schregenberger, Pradeep P. Shirodkar, Grace O. Tsien
  • Patent number: 5525678
    Abstract: A bimetallic catalyst produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two metals of the catalyst producing the HMW and LMW components. The bimetallic catalyst produces a broad/bimodal MWD resin whose HMW and LMW components depend on the relative productivity of each of the transition metal sites of the catalyst. Water and/or carbon dioxide are cofed to the polymerization reactor at levels necessary to modify the weight fractions of the HMW and LMW components, thus achieving a target molecular weight distribution, MWD. The invention allows the resin MWD to be adjusted in the reactor. The weight fraction of the high molecular weight component decreases with the addition of the water and or the carbon dioxide and the FI of the overall product increases with a decrease in the HMW component weight fraction in the product.
    Type: Grant
    Filed: September 22, 1994
    Date of Patent: June 11, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Robert I. Mink, Thomas E. Nowlin, Pradeep P. Shirodkar, Sandra D. Schregenberger, Grace O. Tsien
  • Patent number: 5126414
    Abstract: In accordance with the invention, the process comprises substantially eliminating distributor plate fouling in fluid bed reactor alpha olefin polymerizations, by removing oligomers from the recycle feeds to the fluid bed reactor. In accordance with the invention, the process comprises substantially eliminating gel production in the low pressure production of polymers and copolymers of ethylene. Unexpectedly, the process of the invention, which substantially eliminates distributor plate fouling also results in polymer products which are substantially free of gels.
    Type: Grant
    Filed: November 19, 1991
    Date of Patent: June 30, 1992
    Assignee: Mobil Oil Corporation
    Inventors: Quentin S. Cooke, Glyarpuram N. Prasad, John J. Schlueter, Jr., Grace O. Tsien
  • Patent number: 5034364
    Abstract: An olefin, particularly alpha-olefin, polymerization catalyst composition, supported on a refractory oxide support comprises two chromium specie: (1) CrO.sub.3 or any chromium compound calcinable to CrO.sub.3 ; and (2) at least one silylchromate compound. The composition is prepared by sequentially depositing specie (1) and (2) onto the same support.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: July 23, 1991
    Assignee: Mobil Oil Corporation
    Inventors: Bohumil V. Kral, Grace O. Tsien, Chisung Wu