Patents by Inventor James C. Stevens

James C. Stevens 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: 20030065097
    Abstract: A polymer composition comprises: (a) a high molecular weight, branched component; and (b) a low molecular weight, branched component.
    Type: Application
    Filed: March 15, 2002
    Publication date: April 3, 2003
    Applicant: The Dow Chemical Company
    Inventors: Alexander W. DeGroot, James C. Stevens, Sylvie Y. Desjardins, Jeffrey Weinhold, Edmund Carnahan, David Gillespie, Daniel D. VanderLende
  • Patent number: 6538080
    Abstract: A gas phase fluidized bed process is described for producing ethylene polymers having improved processability and an MWD of less than about 2.9. Multiple reactors in series or parallel may be used to produce in-situ blended polymers. Each reactor can separately have a constrained geometry catalyst or a conventional Ziegler-Natta catalyst as needed for obtaining in-situ blended polymer with the desired properties as long as there is a constrained geometry catalyst in at least one reactor. Olefin polymers can be produced according to this invention which have low susceptibility to melt fracture, even under high shear stress conditions.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: March 25, 2003
    Assignee: BP Chemicals Limited
    Inventors: Robert D. Swindoll, Bruce A. Story, Brian W. S. Kolthammer, Kevin P. Peil, David R. Wilson, James C. Stevens
  • Patent number: 6534612
    Abstract: Elastic ethylene polymers are disclosed which have processability similar to highly branched low density polyethylene (LDPE), but the strength and toughness of linear low density polyethylene (LDPE). The polymers have processing indices (PI's) less than or equal to 70 percent of those of a comparative linear ethylene polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear ethylene polymer at about the same I2and Mw/Mn. The novel polymers can also have from about 0.01 to about 3 long chain branches/1000 total carbons and have higher low/zero shear viscosity and lower high shear viscosity than comparative linear ethylene polymers. The novel polymers can also be characterized as having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: March 18, 2003
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Patent number: 6512049
    Abstract: Sulfonated substantially random interpolymers made from monomer components comprise from 1 to 65 mole percent of (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinylidene monomer, or (c) a combination of at least one vinyl or vinylidene aromatic monomer and at lest one hindered aliphatic or cycloaliphatic vinylidene monomer, and from 35 to 99 mole percent of at least one aliphatic &agr;-olefin having from 2 to 20 carbon atoms; and optionally, from 0 to 20 mole percent of a diene containing from 4 to 20 carbon atoms; wherein the sulfonated interpolymer contains at least one mer (or moiety) of a group represented by the formula —SO3M where M is hydrogen or a group 1, 7 or 12 metal in ionic form or combination thereof. Blends of these polymers with polyamides and polyolefins are made.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: January 28, 2003
    Assignee: Dow Global Technologies Inc.
    Inventors: Yunwa W. Cheung, Stephen F. Hahn, James C. Stevens, Francis J. Timmers, Gregory F. Schmidt, Robert H. Terbrueggen, Thoi H. Ho
  • Patent number: 6506867
    Abstract: Elastic ethylene polymers are disclosed which have processability similar to highly branched low density polyethylene (LDPE), but the strength and toughness of linear low density polyethylene (LLDPE). The polymers have processing indices (PI's) less than or equal to 70 percent of those of a comparative linear ethylene polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear ethylene polymer at about the same I2 and Mw/Mn. The novel polymers can also have from about 0.01 to about 3 long chain branches/1000 total carbons and have higher low/zero shear viscosity and lower high shear viscosity than comparative linear ethylene polymers. The novel polymers can also be characterized as having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: January 14, 2003
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Publication number: 20020183466
    Abstract: A process for polymerization of an olefin comprising contacting one or more olefins, optionally in the presence of an inert aliphatic, alicyclic or aromatic hydrocarbon, with a catalyst system comprising a Group 3-10 metal complex, a dispersible clay catalyst activator comprising finely divided clay having a correlated settling rate less than 0.03 cm/sec, and from 0.001 to 10 mmol/g of clay of a Group 1 to 14 metal alkyl compound. The foregoing process is particularly adapted for use in the preparation of olefin polymers under solution polymerization conditions.
    Type: Application
    Filed: April 19, 2002
    Publication date: December 5, 2002
    Inventors: Edmund M. Carnahan, Alexander Vogel, Daniel D. VanderLende, James C. Stevens
  • Patent number: 6479594
    Abstract: Sulfonated substantially random interpolymers made from monomer components comprise from 1 to 65 mole percent of (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinylidene monomer, or (c) a combination of at least one vinyl or vinylidene aromatic monomer and at least one hindered aliphatic or cycloaliphatic vinylidene monomer, and from 35 to 99 mole percent of at least one aliphatic &agr;-olefin having from 2 to 20 carbon atoms; and optionally, from 0 to 20 mole percent of a diene containing from 4 to 20 carbon atoms; wherein the sulfonated interpolymer contains at least one mer (or moiety) of a group represented by the formula —SO3−M where M is hydrogen or a group 1, 7 or 12 metal in ionic form or combination thereof. Blends of these polymers with polyamides and polyolefins are made.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: November 12, 2002
    Assignee: The Dow Chemical Company
    Inventors: Yunwa W. Cheung, Stephen F. Hahn, James C. Stevens, Francis J. Timmers, Gregory F. Schmidt, Thoi H. Ho, Robert H. Terbrueggen
  • Patent number: 6476283
    Abstract: Organic compounds are hydrogenated in the presence of certain bis(pentadienyl) divalent Group IV metal complexes having &pgr;-bound, neutral, conjugated diene ligands. These complexes are effective hydrogenation catalysts for polymers containing ethylenic unsaturation. They further provide for selective hydrogenation of ethylenic unsaturation sites in the presence of aromatic groups.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: November 5, 2002
    Assignee: The Dow Chemical Company
    Inventors: David D. Devore, James C. Stevens, Stephen F. Hahn, Francis J. Timmers, David R. Wilson
  • Patent number: 6465384
    Abstract: Biscyclopentadienyl, Group 4 transition metal complexes formed with conjugated dienes wherein the diene is bound to the transition metal either in the form of a &sgr;-complex or a &pgr;-complex in combination with strong Lewis acids, Bronsted acid salts, carbenium ion salts, salts containing a cationic oxidizing agent, or subjected to bulk electrolysis in the presence of compatible, inert non-coordinating anions form catalysts for polymerizing olefins, diolefins and/or acetylenically unsaturated monomers.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 15, 2002
    Assignee: The Dow Chemical Company
    Inventors: Francis J. Timmers, James C. Stevens, David D. Devore, Robert K. Rosen, Jasson T. Patton, David R. Neithamer
  • Publication number: 20020128403
    Abstract: Metal complexes having constrained geometry and a process for preparation thereof, addition polymerization catalysts formed therefrom, processes for preparation of such addition polymerization catalysts, methods of use, and novel polymers formed thereby, including ElPE resins and pseudo-random copolymers, are disclosed and claimed.
    Type: Application
    Filed: November 6, 2001
    Publication date: September 12, 2002
    Inventors: James C. Stevens, Robert K. Rosen
  • Patent number: 6420507
    Abstract: The subject invention is directed to an olefin polymer produced by polymerizing at least one &agr;-olefin in the presence of a Group 4 metal complex comprising an indenyl group substituted in the 2 or 3 position with at least one group selected from hydrocarbyl, perfluoro-substituted hydrocarbyl, silyl, germyl and mixtures thereof, said indenyl group further being covalently bonded to the metal by means of a divalent ligand group, wherein the divalent ligand comprises nitrogen or phosphorus having an aliphatic or alicyclic hydrocarby group covalently bonded thereto via a primary or secondary carbon. Preferred olefin polymers of the invention will be characterized as having a high molecular weight, narrow molecular weight distribution, high vinyl content, and a bimodal DSC melting curve or a deconvoluted ATREF or GPC curve which shows at least two distinct narrow peaks.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: July 16, 2002
    Assignee: The Dow Chemical Company
    Inventors: Lawrence T. Kale, Daniel D. Vanderlende, Peter N. Nickias, Jasson T. Patton, James C. Stevens, Deepak R. Parikh, Debra J. Mangold
  • Patent number: 6348555
    Abstract: The present invention pertains to a substantially linear olefin polymer which has long chain branches, a high melt flow ratio, a narrow molecular weight distribution and critical shear rate at onset of surface melt fracture of a least 50 percent greater than the critical shear rate at the onset of melt fracture which is substantially higher than that of a linear olefin polymer having about the same molecular weight and molecular weight distribution. The novel polymer is an interpolymer of ethylene with at least one C3-C20 alpha-olefin and at least one unsaturated monomer.
    Type: Grant
    Filed: April 22, 1997
    Date of Patent: February 19, 2002
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Publication number: 20010041776
    Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.
    Type: Application
    Filed: June 19, 2001
    Publication date: November 15, 2001
    Inventors: Shih-Yaw Lai, George W. Knight, John R. Wilson, James C. Stevens, Pak-Wing Steve Chum
  • Patent number: 6136937
    Abstract: Elastic ethylene polymers are disclosed which have processability similar to highly branched low density polyethylene (LDPE), but the strength and toughness of linear low density polyethylene (LLDPE). The polymers have processing indices (PI's) less than or equal to 70 percent of those of a comparative linear ethylene polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear ethylene polymer at about the same I.sub.2 and M.sub.w /M.sub.n. The novel polymers can also have from about 0.01 to about 3 long chain branches/1000 total carbons and have higher low/zero shear viscosity and lower high shear viscosity than comparative linear ethylene polymers. The novel polymers can also be characterized as having a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63, a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation: M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: October 24, 2000
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
  • Patent number: 6107374
    Abstract: Bitumens can be blended with interpolymers prepared from least one olefin and at least one vinyl or vinylidene aromatic monomer and, optionally, at least one diene. The interpolymers prepared from monomers containing a diene are new compositions of matter. When the interpolymers prepared from monomers containing a diene are blended with a bitumen, the blends are crosslinkable.
    Type: Grant
    Filed: July 23, 1998
    Date of Patent: August 22, 2000
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, Francis J. Timmers, Arnold L. Gatzke, Corwin J. Bredeweg, Kevin W. McKay, William A. Gros, Charles F. Diehl
  • Patent number: 6087447
    Abstract: Blends of polymeric materials comprising (A) from about 1 to about 99 weight percent of at least one interpolymer containing (1) from about 1 to about 65 mole percent of (a) at least one vinylidene aromatic monomer, or (b) at least one hindered aliphatic vinylidene monomer, or (c) a combination of at least one vinylidene aromatic monomer and at least one hindered aliphatic vinylidene monomer, and (2) from about 35 to about 99 mole percent of at least one aliphatic .alpha.-olefin having from 2 to about 20 carbon atoms; and (B) from about 1 to about 99 weight percent of at least one homopolymer or interpolymer of one or more vinylidene aromatic monomers and/or one or more hindered aliphatic vinylidene monomers. These blends have been observed to possess improved properties when compared to the individual polymers comprising the blend and to provide materials with enhanced processability and temperature ranges of performance.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: July 11, 2000
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, Francis J. Timmers, Martin J. Guest, John J. Gathers, Yunwa W. Cheung, Pak-Wing S. Chum, Chung P. Park, George P. Clingerman, Kevin D. Sikkema
  • Patent number: 6074977
    Abstract: Catalyst compositions that are highly tolerant of catalyst poisons comprising a cationic or zwitterionic Group 4 metal complex of the constrained geometry type and an organoaluminum hydrocarbyloxide compound according to the formula R.sup.1.sub.2 Al(OR.sup.2),wherein R.sup.1 and R.sup.2 independently each ocurrence are C.sub.1-30 hydrocarbyl,the molar ratio of complex to organoaluminum hydrocarbyloxide compound being from 1:0.1 to 1:100.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: June 13, 2000
    Assignee: The Dow Chemical Company
    Inventors: Robert K. Rosen, James C. Stevens, John C. Tracy
  • Patent number: 6075077
    Abstract: The subject invention is directed to a composition comprising a polymer, comprising in polymerized form ethylene and at least one additional polymerizable monomer, prepared by polymerizing ethylene and said at least one addition polymerizable monomer in the presence of a catalyst comprising a recited cyclopentadienyl group-containing metal coordination complex and an activating cocatalyst, wherein said composition is an asphalt, bitumen, or adhesive composition.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: June 13, 2000
    Assignee: The Dow Chemical Company
    Inventors: Francis J. Timmers, James C. Stevens
  • Patent number: 6060567
    Abstract: Interpolymers having long chain branches are claimed. These interpolymers are made by continuous polymerization processes, including a process comprising the steps of: (a) contacting ethylene and at least one C.sub.3 -C.sub.20 alpha-olefin with a catalyst composition in a polymerization reactor under continuous polymerization conditions in a polymerization reactor, wherein said catalyst composition is made from components comprising:(1) a metal coordination complex comprising a metal atom of groups 3-10 or the Lanthanide series of the Periodic Table of Elements and a cyclic, delocalized .pi.-bonded moiety and(2) an activating cocatalyst; and(b) removing the interpolymer having long chain branches via a reactor exit stream. The interpolymers comprise ethylene with at least one C.sub.3 -C.sub.20 alpha-olefin and have a variety of properties, including from 0.01 to 3 long chain branches per thousand carbons, a melt flow ratio I.sub.10 /I.sub.2 .gtoreq.5.63, and a molecular weight distribution, M.sub.w /M.sub.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: May 9, 2000
    Assignee: The Dow Chemical Company
    Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens, Pak-Wing Steve Chum
  • Patent number: 6025448
    Abstract: A gas phase fluidized bed process is described for producing ethylene polymers having improved processability and an MWD of less than about 2.9. Multiple reactors in series or parallel may be used to produce in-situ blended polymers. Each reactor can separately have a constrained geometry catalyst or a conventional Ziegler-Natta catalyst as needed for obtaining in-situ blended polymer with the desired properties as long as there is a constrained geometry catalyst in at least one reactor. Olefin polymers can be produced according to this invention which have low susceptibility to melt fracture, even under high shear stress conditions.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: February 15, 2000
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Swindoll, Bruce A. Story, Brian W. S. Kolthammer, Kevin P. Peil, David R. Wilson, James C. Stevens