Patents by Inventor Howard C. Welborn, Jr.

Howard C. Welborn, Jr. 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: 5633394
    Abstract: Compounds useful as catalyst components for olefin polymerization. The compounds comprise derivatives of cyclopentadienyl complexes of the ZR or HF.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: May 27, 1997
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Howard C. Welborn, Jr., John A. Ewen
  • Patent number: 5580939
    Abstract: Catalysts comprising (a) derivatives of mono, bi and tricyclopentadienyl coordination complexes with a transition metal and (b) an alumoxane are employed in a process of producing polyolefins of controlled molecular weight.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 3, 1996
    Assignee: Exxon Chemical Patents Inc.
    Inventors: John A. Ewen, Howard C. Welborn, Jr.
  • Patent number: 5441920
    Abstract: Silicon-bridged transition metal compounds and their use as alpha-olefin polymerization catalysts are disclosed. The polymerization catalyst comprises a chiral silicon-bridged metallocene of the following structure: ##STR1## where M is a transition metal, X' and X" are the same or different hydride, halogen, hydrocarbyl or halohydrocarbyl groups having up to about 6 carbon atoms, A' and A" are each the same or different asymmetrical mononuclear or polynuclear hydrocarbyl or silahydrocarbyl moieties and S' is a bridge of 1-4 atoms selected from the group consisting of silanylene, silaalkylene, oxasilanylene, and oxasilaalkylene, and may include an alumoxane. Specifically, the transition metals are titanium, zirconium, and hafnium.
    Type: Grant
    Filed: December 2, 1993
    Date of Patent: August 15, 1995
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5382631
    Abstract: Linear interpolymer blends are disclosed. The blends are made from components having a narrow molecular weight distribution (e.g. Mw/Mn.ltoreq.3) and a narrow composition distribution (e.g. CDBI>50%). The blend components of the blend can all have the same molecular weight but different comonomer contents, the same comonomer content but different molecular weights, or comonomer contents which increase with molecular weight. The blends have either Mw/Mn>3 and/or CDBI<50%, and combinations of each, and can be bimodal with respect to either or both molecular weight and/or comonomer content. The blends are generally free of blend components having both a higher average molecular weight and a lower average comonomer content than another blend component. The blends can have improved mechanical, physical and/or chemical properties. Single or multilayer films having enhanced physical properties are made from the blends.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: January 17, 1995
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Ferdinand C. Stehling, Charles S. Speed, Howard C. Welborn, Jr., deceased
  • Patent number: 5324800
    Abstract: Catalysts comprising (a) derivatives of mono, bi and tricyclopentadienyl coordination complexes with a transition metal and (b) and an alumoxane are employed in a process of producing polyolefins of controlled molecular weight.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: June 28, 1994
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Howard C. Welborn, Jr., John A. Ewen
  • Patent number: 5314973
    Abstract: Silicon-bridged transition metal compounds and their use as .alpha.-olefin polymerization catalysts are disclosed. A chiral silicon-bridged metallocene catalyst polymerizes .alpha.-olefins to high isotacity with a minimum of inversions at high rates of catalyst activity. The catalyst is easily made in high yields and readily separated from atactic meso forms.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: May 24, 1994
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5191052
    Abstract: Ethylene 1,3 Butadiene copolymers having in their structure cyclopentane rings connected in a trans 1,2 position. The ethylene copolymers of the invention may be formed from polymerization of ethylene and 1,3 butadiene and preferably have a predominance of the copolymer units formed as trans 1,2-cyclopentane, the remainder of the 1,3 butadiene comonomer being incorporated as the noncyclic.
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: March 2, 1993
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5183867
    Abstract: An olefin polymerization supported catalyst comprising the supported reaction product of at least one metallocene of a metal of Group IVB, VB, and VIB of the Periodic Table, a non-metallocene transition metal containing compound of a Group IVB, VB, or VIB metal and an alumoxane, said reaction product formed in the presence of the support. The supported product is highly useful for the polymerization of olefins especially ethylene and especially for the copolymerization of ethylene and other mono and diolefins.
    Type: Grant
    Filed: August 22, 1991
    Date of Patent: February 2, 1993
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5124418
    Abstract: An olefin polymerization catalyst comprising (a) a supported transition metal containing component comprising the support treated with at least one metallocene and at least one non-metallocene transition metal compound, and a cocatalyst comprising an alumoxane and an organometallic compound of a metal of Groups IA, IIA, IIB, or IIIA of the Periodic Table.
    Type: Grant
    Filed: December 2, 1988
    Date of Patent: June 23, 1992
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5120867
    Abstract: Silicon-bridged transition metal compounds and their use as .alpha.-olefin polymerization catalysts are disclosed. A chiral silicon-bridged metallocene catalyst polymerizes .alpha.-olefins to high isotacity with a minimum of inversions at high rates of catalyst activity. The catalyst is easily made in high yields and readily separated from atactic meso forms.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: June 9, 1992
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5084534
    Abstract: A process for polymerizing or copolymerizing ethylene, either alone or in combination with other olefins, comprising contacting said ethylene or alpha-olefin, either alone or in combination with other olefins, with a catalyst comprising a cyclopentadienyl-transition metal compound and an alumoxane compound at an elevated temperature and pressure and wherein the ratio of aluminum in the alumoxane to the total metal in the metallocene is in the range of 1000:1 to 0.5:1.
    Type: Grant
    Filed: September 10, 1987
    Date of Patent: January 28, 1992
    Assignee: Exxon Chemical Patents, Inc.
    Inventors: Howard C. Welborn, Jr., Charles S. Speed
  • Patent number: 5077255
    Abstract: An olefin polymerization supported catalyst comprising the supported reaction product of at least one metallocene of a metal of Group IVB, VB, and VIB of the Periodic Table, a non-metallocene transition metal containing compound of a Group IBV, VB, or VIB metal and an alumoxane, said reaction product formed in the presence of the support. The supported product is highly useful for the polymerization of olefins especially ethylene and especially for the copolymerization of ethylene and other mono and diolefins.
    Type: Grant
    Filed: September 10, 1986
    Date of Patent: December 31, 1991
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5017714
    Abstract: Silicon-bridged transition metal compounds and their use as .alpha.-olefin polymerization catalysts are disclosed. A chiral silicon-bridged metallocene catalyst polymerizes .alpha.-olefins to high isotacity with a minimum of inversions at high rates of catalyst activity. The catalyst is easily made in high yields and readily separated from atactic meso forms.
    Type: Grant
    Filed: September 7, 1989
    Date of Patent: May 21, 1991
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 5001244
    Abstract: Olefin polymerization catalysts, and methods for their preparation, comprising a metallocene and the reaction product of a hydrocarbylaluminum with a trihydrocarbylboroxine. The catalyst may be homogeneous or supported.
    Type: Grant
    Filed: July 13, 1990
    Date of Patent: March 19, 1991
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 4952714
    Abstract: A process for the preparation of hydrocarbylalumoxanes comprising oligomeric, linear and/or cyclic hydrocarbylalumoxanes which comprise contacting a hydrocarbylaluminum dissolved in an inert dry organic liquid with a trihydrocarbylboroxine. Preferably, the trihydrocarbylboroxine is prepared by the reaction of boron oxide with trihydrocarbylborane.
    Type: Grant
    Filed: August 8, 1989
    Date of Patent: August 28, 1990
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 4937299
    Abstract: Polyolefin reactor blends obtained by polymerization of ethylene and higher alpha-olefins in the presence of a catalyst system comprising two or more metallocenes and alumoxane.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: June 26, 1990
    Assignee: Exxon Research & Engineering Company
    Inventors: John A. Ewen, Howard C. Welborn, Jr.
  • Patent number: 4935474
    Abstract: Polyolefins having a broad molecular weight distribution are obtained by polymerizing ethylene or higher alpha-olefins in the presence of a catalyst system comprising two or more metallocenes each having different propagation and termination rate constants and alumoxane.
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: June 19, 1990
    Assignee: Exxon Research & Engineering Company
    Inventors: John A. Ewen, Howard C. Welborn, Jr.
  • Patent number: 4897455
    Abstract: An olefin polymerization supported catalyst comprising a support and the reaction product of a metallocene of Group 4b, 5b or 6b of the Periodic Table and an alumoxane, said reaction product formed in the presence of a support.
    Type: Grant
    Filed: December 2, 1988
    Date of Patent: January 30, 1990
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 4808561
    Abstract: An olefin polymerization supported catalyst comprising a support and the reaction product of a metallocene of Group 4b, 5b or 6b of the Periodic Table and an alumoxane, said reaction product formed in the presence of a support.
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: February 28, 1989
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.
  • Patent number: 4701432
    Abstract: An olefin polymerization catalyst comprising (a) a supported transition metal containing component comprising the support treated with at least one metallocene and at least one non-metallocene transition metal compound, and a cocatalyst comprising an alumoxane and an organometallic compound of a metal of Groups IA, IIA, IIB, or IIIA of the Periodic Table.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: October 20, 1987
    Assignee: Exxon Chemical Patents Inc.
    Inventor: Howard C. Welborn, Jr.