Patents by Inventor Brian W. S. Kolthammer

Brian W. S. Kolthammer 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: 5844045
    Abstract: Processes for polymerizing ethylene/.alpha.-olefin interpolymer compositions are disclosed. The interpolymer compositions have a controlled composition and a controlled molecular weight distribution. The processes utilize a highly-efficient homogeneous catalyst composition in at least one reactor to produce a first interpolymer having a narrow composition distribution and a narrow molecular weight distribution, and a highly-efficient heterogeneous Ziegler catalyst in at least one other reactor. The reactors can be operated sequentially or separately, depending upon the desired product. The novel compositions have good optical properties (e.g., clarity and haze) and good physical properties (e.g., modulus, yield strength, toughness and tear). Useful products which can be formed from these compositions include film, molded articles and fiber.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: December 1, 1998
    Assignee: The Dow Chemical Company
    Inventors: Brian W. S. Kolthammer, Robert S. Cardwell
  • Patent number: 5763547
    Abstract: A supported catalyst composition comprising a complex of a Group 4 metal cyclopentadienyl derivative reacted with silica treated with an aluminoxane demonstrates improved reactivity, especially for incorporating long chain alpha-olefins and also shows improved resistance to catalyst poisoning. The supported catalyst composition is adapted to produce homogeneous polymers, copolymers, terpolymers, etc., for example, homogeneous polyethylene, homogeneous poly(ethylene-octene) copolymers and the like. The invention further includes the process of preparing the supported catalyst compositions and a process for preparing olefinic polymers using these catalyst compositions.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: June 9, 1998
    Assignee: The Dow Chemical Company
    Inventors: Brian W. S. Kolthammer, John C. Tracy, Robert S. Cardwell, Robert K. Rosen
  • Patent number: 5703257
    Abstract: A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihydrocarbyloxy coordination complexes (I) by contacting in the presence of an aprotic organic diluent a metal compound of the formula M(OR).sub.4 with a dianionic salt compound. A process for preparing bridged mono- and bis(cyclopentadienyl) dihydrocarbyl metal coordination complexes (II) by contacting a complex (I) with a hydrocarbylation agent. A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihalide coordination complexes (III) by contacting a complex (I) with a halogenation agent.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 30, 1997
    Assignee: The Dow Chemical Company
    Inventors: Robert K. Rosen, Brian W.S. Kolthammer
  • Patent number: 5565547
    Abstract: Novel catalyst compositions comprising a cationic transition metal complex of the formula(Pd(II)S.sub.4-x L.sub.x).sup.+2 (A).sup.-n ywherein:Pd(II) is palladium having a valence of +2;S is a synthesis solvent;L is a monodendate, bidendate or tridendate ligand or ligands having one or more bonding sites;x is an integer from 1 to 3 and is equal to the total number of ligand bonding sites;A is a weakly or non-coordinating anion capable or stabilizing the complex in its cationic form; andn is 1 or 2 and y is 2 or 1;provided that(i) when n is 1, y is 2 and when n is 2, y is 1; and(ii) when the anion A is tetrafluoroborate, the organometallic complex is not (tris(acetonitrile) palladium(II) triphenylphosphine), bis(acetonitrile) palladium(II) bis(triphenylphosphine)), ((acetonitrile) palladium (II) tris(triphenylphosphine)) or (bis(acetonitrile)palladium(II) 1,3-bis (diphenylphosphino)propane).
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: October 15, 1996
    Assignee: The Dow Chemical Company
    Inventors: John G. Hefner, Brian W. S. Kolthammer
  • Patent number: 5554777
    Abstract: Novel catalyst compositions comprising a cationic transition metal complex containing palladium, a mono-, di-, or tridendate ligand, and an anion are disclosed. The novel catalyst compositions can be used in a process for polymerizing carbon monoxide and at least one ethylenically unsaturated hydrocarbon to produce linear alternating polymers. Processes for preparing the novel catalyst compositions are also disclosed.
    Type: Grant
    Filed: July 8, 1994
    Date of Patent: September 10, 1996
    Assignee: The Dow Chemical Compamy
    Inventors: John G. Hefner, Brian W. S. Kolthammer
  • Patent number: 5512693
    Abstract: Titanium and zirconium complexes comprising a single, cyclic, delocalized n-bonded ligand group wherein the metal of said complexes is in the +2 formal oxidation state are prepared in high yield and purity by reaction of titanium and zirconium halides in the +3 or +4 oxidation state with an n-alkyl Grignard reagent. The complexes are used as catalyst components for .alpha.-olefin polymerization catalysts.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: April 30, 1996
    Assignee: The Dow Chemical Company
    Inventors: Robert K. Rosen, Brian W. S. Kolthammer
  • Patent number: 5504223
    Abstract: A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihydrocarbyloxy coordination complexes (I) by contacting in the presence of an aprotic organic diluent a metal compound of the formula M(OR).sub.4 with a dianionic salt compound. A process for preparing bridged mono- and bis(cyclopentadienyl)dihydrocarbyl metal coordination complexes (II) by contacting a complex (I) with a hydrocarbylation agent. A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihalide coordination complexes (III) by contacting a complex (I) with a halogenation agent.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: April 2, 1996
    Assignee: The Dow Chemical Company
    Inventors: Robert K. Rosen, Brian W. S. Kolthammer
  • Patent number: 5487938
    Abstract: A transition metal containing catalyst useful for the polymerization of .alpha.-olefins is prepared by (A) forming in an inert atmosphere which excludes oxygen and moisture a slurry of (1) a porous inorganic oxide support material selected from the group consisting of silica, alumina, or a combination of silica and alumina, said support material containing not greater than about 5 millimoles of hydroxyl groups per gram of support material and a particle size not greater than about 10 microns and a surface area of from about 50 to about 800 m.sup.2 /g in an inert organic liquid medium; (B) mixing said slurry with (2) an alkoxide and stirring the resultant mixture at a temperature of from about -20.degree. C. to about 120.degree. C. for a time sufficient to saturate the surface of the support material; (C) mixing the product form (B) with (3) a titanium compound or a combination of a titanium compound and (4) a vanadium compound and stirring the resultant mixture at a temperature of from about -20.degree. C.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: January 30, 1996
    Assignee: The Dow Chemical Company
    Inventors: Lee Spencer, Brian W. S. Kolthammer, Miriam P. Ripplinger, Jeffrey J. Wooster, Pak-Wing S. Chum, Jacquelyn A. deGroot
  • Patent number: 5453410
    Abstract: An addition polymerization catalyst comprising a cationic complex of a Group 4 metal cyclopentadienyl derivative and an alumoxane shows improved resistance to catalyst poisons.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: September 26, 1995
    Assignee: The Dow Chemical Company
    Inventors: Brian W. S. Kolthammer, Robert S. Cardwell, John C. Tracy
  • Patent number: 5420090
    Abstract: A transition metal containing catalyst useful for the polymerization of .alpha.-olefins is prepared by (A) forming in an inert atmosphere which excludes oxygen and moisture a slurry of (1) a porous inorganic oxide support material selected from the group consisting of silica, alumina, or a combination of silica and alumina, said support material containing not greater than about 5 millimoles of hydroxyl groups per gram of support material and a particle size not greater than about 10 microns and a surface area of from about 50 to about 800 m.sup.2 /g in an inert organic liquid medium; (B) mixing said slurry with (2) an alkoxide and stirring the resultant mixture at a temperature of from about -20.degree. C. to about 120.degree. C. for a time sufficient to saturate the surface of the support material: (C) mixing the product form (B) with (3) a titanium compound or a combination of a titanium compound and (4) a vanadium compound and stirring the resultant mixture at a temperature of from about -20.degree. C.
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: May 30, 1995
    Assignee: The Dow Chemical Company
    Inventors: Lee Spencer, Brian W. S. Kolthammer
  • Patent number: 5312938
    Abstract: Olefins are polymerized in the presence of a homogeneous catalyst represented by the formula LTi(NR.sub.2).sub.3 wherein L is a .sub.II -bonded ligand selected from the group consisting of indenyl, C.sub.1 -C.sub.4 alkyl substituted indenyl, --OSiR.sub.3 substituted indenyl, R is a C.sub.1 -C.sub.4 alkyl group wherein each R attached to the same nitrogen atom is the same, but the R groups attached to different nitrogen atoms can be the same or different from those attached to the other nitrogen atoms.
    Type: Grant
    Filed: April 2, 1993
    Date of Patent: May 17, 1994
    Assignee: The Dow Chemical Company
    Inventors: John G. Hefner, Brian W. S. Kolthammer
  • Patent number: 5231151
    Abstract: A transition metal containing catalyst useful for the polymerization of .alpha.-olefins is prepared by (A) forming in an inert atmosphere which excludes oxygen and moisture a slurry of (1) a porous inorganic oxide support material selected from the group consisting of silica, alumina, or a combination of silica and alumina, said support material containing not greater than about 5 millimoles of hydroxyl groups per gram of support material and a particle size not greater than about 10 microns and a surface area of from about 50 to about 800 m.sup.2 /g in an inert organic liquid medium; (B) mixing said slurry with (2) an alkoxide and stirring the resultant mixture at a temperature of from about -20.degree. C. to about 120.degree. C. for a time sufficient to saturate the surface of the support material; (C) mixing the product form (B) with (3) a titanium compound or a combination of a titanium compound and (4) a vanadium compound and stirring the resultant mixture at a temperature of from about -20.degree. C.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: July 27, 1993
    Assignee: The Dow Chemical Company
    Inventors: Lee Spencer, Brian W. S. Kolthammer, Miriam P. Ripplinger, Jeffrey J. Wooster, Pak-Wing S. Chum, Jacquelyn A. deGroot
  • Patent number: 5194532
    Abstract: Olefins are polymerized in the presence of a homogeneous catalyst represented by the formula LTi(NR.sub.2).sub.3 wherein L is a .pi.-bonded ligand selected from the group consisting of indenyl, C.sub.1 -C.sub.4 alkyl substituted indenyl, --OSiR.sub.3 substituted indenyl, R is a C.sub.1 -C.sub.4 alkyl group wherein each R attached to the same nitrogen atom is the same, but the R groups attached to different nitrogen atoms can be the same or different from those attached to the other nitrogen atoms.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: March 16, 1993
    Assignee: The Dow Chemical Company
    Inventors: John G. Hefner, Brian W. S. Kolthammer, Dennis R. Gifford
  • Patent number: 4767860
    Abstract: N-substituted piperazinones are prepared by reacting an N-substituted ethylenediamine such as N,N'-dimethylethylenediamine with a 2-oxoaldehyde such as glyoxal. N-substituted piperazinones are useful as flue gas desulfurization agents.
    Type: Grant
    Filed: October 14, 1986
    Date of Patent: August 30, 1988
    Assignee: The Dow Chemical Company
    Inventors: Gordon C. Dunmore, Kevin C. Taylor, Brian W. S. Kolthammer