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).

  • Patent number: 7300983
    Abstract: A polymer composition that has a backbone chain; and a plurality of long chain branches connected to the backbone is described. The polymer composition also has a value of 2g?LCB-1g?LCB that is less than about 0.22, where 1g?LCB is the long chain branching index for a fraction of the composition having a Mw of 100,000 and 2g?LCB is the long chain branching index for a fraction of the composition having a Mw of 500,000.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: November 27, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: Alexander W. Degroot, James C. Stevens, Sylvie Y. Desjardins, Jeffrey Weinhold, Edmund M. Carnahan, David Gillespie, Daniel D. Vanderlende
  • Patent number: 7271221
    Abstract: Olefin polymers having a melt strength of about 5cN at 190 ° C., and when made into a film have a CD shrink of at least 20%. Some of the polymers have a comb-like structure with at least 0.3 long-chain branches per 1000 carbon atoms are disclosed. Some compositions described herein include a high molecular weight fraction and a low molecular weight fraction wherein the ratio of the molecular weight of the high molecular weight fraction to the molecular weight of the low molecular weight fraction is greater than about 1.3.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: September 18, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. VanderLende
  • Patent number: 7250470
    Abstract: A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene, and as having at least one of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: February 22, 2006
    Date of Patent: July 31, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 7250471
    Abstract: Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: February 22, 2006
    Date of Patent: July 31, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 7238759
    Abstract: Unique copolymers comprising propylene, ethylene and/or one or more unsaturated comonomers are characterized as having: at least one, preferably more than one, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta catalyst These polypropylene polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst. These polymers can be blended with other polymers, and are useful in the manufacture of films, sheets, foams, fibers and molded articles.
    Type: Grant
    Filed: November 15, 2004
    Date of Patent: July 3, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende
  • Patent number: 7222673
    Abstract: A method for releasing gas from a gas hydrate without melting the gas hydrate by substituting the gas with a releasing agent that forms a more stable hydrate structure than the gas.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: May 29, 2007
    Assignee: ConocoPhilips Company
    Inventors: Arne Graue, Bjorn Kvamme, David R. Zornes, James C. Stevens, James J. Howard, Bernard A. Baldwin
  • Patent number: 7214638
    Abstract: Catalyst compositions that are highly tolerant of catalyst poisons for use in addition polymerizations comprising a catalytic derivative of a Group 4 metal complex, a cocatalyst, and a Group 13 metal amide compound.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: May 8, 2007
    Assignee: Dow Global Technologies Inc.
    Inventors: Duane R. Romer, James C. Stevens, Robert K. Rosen, Francis J. Timmers, Hendrik E. Tuinstra
  • Patent number: 7199203
    Abstract: Fibers comprising a propylene homopolymer or a copolymer of propylene and at least one of ethylene and one or more unsaturated comonomers exhibit desirable properties. The homopolymers are characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. The copolymers are characterized as (A) comprising at least about 60 weight percent (wt %) of units derived from propylene, and (B) having at least one of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: June 9, 2005
    Date of Patent: April 3, 2007
    Assignee: Dow Global Technologies, Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Samuel Ethiopia
  • Patent number: 7148305
    Abstract: Olefin polymers having a comb-like structure with at least 0.3 long-chain branches per 1000 carbon atoms are disclosed. Some compositions have a melt strength of about 5 cN at 190° C., and when made into a film have a CD shrink of at least 20%. Some compositions described herein include a high molecular weight fraction and a low molecular weight fraction wherein the ratio of the molecular weight of the high molecular weight fraction to the molecular weight of the low molecular weight fraction is greater than about 1.3.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: December 12, 2006
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. VanderLende
  • Patent number: 7109269
    Abstract: Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: September 19, 2006
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 7060754
    Abstract: A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene, and as having at least one of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: June 13, 2006
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 6960635
    Abstract: Unique copolymers comprising propylene, ethylene and/or one or more unsaturated comonomers are characterized as having: at least one, preferably more than one, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta catalyst. These polypropylene polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst. These polymers can be blended with other polymers, and are useful in the manufacture of films, sheets, foams, fibers and molded articles.
    Type: Grant
    Filed: May 5, 2002
    Date of Patent: November 1, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende
  • Patent number: 6953764
    Abstract: Group 4 metal complexes useful as addition polymerization catalysts of the formula: wherein G1 is a group containing from 1 to 40 atoms not counting hydrogen; T is a divalent bridging group of from 10 to 30 atoms not counting hydrogen, selected from mono- or di-aryl-substituted methylene or silylene groups or mono- or di-heteroaryl-substituted methylene or silylene groups, wherein at least one such aryl- or heteroaryl-substituent is substituted in one or both ortho-positions with a secondary or tertiary alkyl-group, a secondary or tertiary heteroalkyl group, a cycloalkyl group, or a heterocycloalkyl group, G2 is a C6-20 heteroaryl group containing Lewis base functionality, M is the Group 4 metal, X?? is an anionic, neutral or dianionic ligand group, x?? is a number from 0 to 5, and bonds, optional bonds and electron donative interactions are represented by lines, dotted lines and arrows respectively.
    Type: Grant
    Filed: May 2, 2003
    Date of Patent: October 11, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: Kevin A. Frazier, Harold Boone, Paul C. Vosejpka, James C. Stevens
  • Patent number: 6943215
    Abstract: Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: September 13, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 6927256
    Abstract: A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene, and as having at least one of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: August 9, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Patricia Ansems
  • Patent number: 6924342
    Abstract: A polymerization process comprises contacting one or more olefinic comonomers in the presence of at least a high molecular weight catalyst and at least a low molecular weight catalyst in a single reactor, and effectuating the polymerization of the olefinic comonomers in the reactor to obtain an olefin polymer. Preferably, both catalysts have the ability to incorporate a substantially similar amount of comonomers in the olefin polymer. The polymers produced by the process may have a relatively higher level of long chain branching while maintaining a relatively narrow molecular weight distribution, i.e., MWD less than about 6. These interpolymers may exhibit processability similar to or better than LDPE but have physical properties similar to metallocene catalyzed polymers.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: August 2, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. VanderLende
  • Patent number: 6906160
    Abstract: Fibers comprising a propylene homopolymer or a copolymer of propylene and at least one of ethylene and one or more unsaturated comonomers exhibit desirable properties. The homopolymers are characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. The copolymers are characterized as (A) comprising at least about 60 weight percent (wt %) of units derived from propylene, and (B) having at least one of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: June 14, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: James C. Stevens, Daniel D. Vanderlende, Samuel Ethiopia
  • Patent number: 6884857
    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: Grant
    Filed: April 13, 1998
    Date of Patent: April 26, 2005
    Assignee: The Dow Chemical Company
    Inventors: James C. Stevens, David R. Wilson
  • Patent number: 6875816
    Abstract: A polymer composition comprises: (a) a high molecular weight, branched component; and (b) a low molecular weight, branched component. Some polymer compositions are characterized by a substantial absent of amyl or methyl branches and a melt strength (MS) that satisfies the following relationship: MS ? x I 2 + y where x is greater than or equal to about 12.5 and y is greater than or equal to about 3. Some polymers are characterized by a melt strength (MS) that satisfies the following relationship: MS ? x I 2 + y where x is greater than or equal to about 3 and y is greater than or equal to about 4.5 and a molecular weight distribution of greater than 3. A process for making polymers is also disclosed.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: April 5, 2005
    Assignee: Dow Global Technologies Inc.
    Inventors: Alexander W. DeGroot, James C. Stevens, Sylvie Y. Desjardins, Jeffrey Weinhold, Edmund Carnahan, David Gillespie, Daniel D. VanderLende
  • Patent number: 6858557
    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: Grant
    Filed: April 13, 1998
    Date of Patent: February 22, 2005
    Assignee: The Dow Chemical Company
    Inventor: James C. Stevens