Patents by Inventor Robert D. Mahoney

Robert D. Mahoney 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: 5888434
    Abstract: The invention relates to a process for preparing a microporous membrane from an unsulfonated poly(phenylene sulfide) polymer by forming a mixture of an unsulfonated poly(phenylene sulfide) polymer, an amorphous polymer, and optionally a plasticizer, heating the resulting mixture, extruding or optionally casting the mixture into a membrane, controlled cooling (quenching) or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, and/or after leaching.
    Type: Grant
    Filed: February 3, 1993
    Date of Patent: March 30, 1999
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, Jiro Kawamoto, Richard A. Lundgard, Mark F. Sonnenschein, Hawk S. Wan, H. Nelson Beck
  • Patent number: 5246647
    Abstract: The present invention relates to a process for preparing a microporous permselective membrane from a poly(phenylene sulfide) (PPS) polymer, an organic compound which substantially solubilizes the PPS below its melting point to form a homogenous mixture, heating the resulting mixture, extruding or casting the mixture into a membrane (fiber or film), quenching or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, after leaching, or a combination thereof. In one embodiment, the solvent optionally includes an organic non-solvent to assist in obtaining the desired microporsity. The permselective polymers are useful to separate gaseous or liquid components from a mixture of components.
    Type: Grant
    Filed: August 19, 1991
    Date of Patent: September 21, 1993
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Robert D. Mahoney, Hawk S. Wan, Chieh-Chun Chau, Timothy M. Finney, Ritchie A. Wessling, Jiro Kawamoto, Mark F. Sonnenschein
  • Patent number: 5227101
    Abstract: The invention relates to a process for preparing a microporous membrane from an unsulfonated poly(etheretherketone)-type polymer by forming a mixture of an unsulfonated poly(etheretherketone)-type polymer, a low melting point crystallizable polymer, and a plasticizer, heating the resulting mixture, extruding or casting the mixture into a membrane, quenching or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, after leaching, or a combination thereof.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: July 13, 1993
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, H. Nelson Beck, Richard A. Lundgard, Hawk S. Wan, Jiro Kawamoto, Mark F. Sonnenschein
  • Patent number: 5205968
    Abstract: The invention relates to a process for preparing a microporous membrane from an unsulfonated poly(etheretherketone)-type polymer by forming a mixture of an unsulfonated poly(etheretherketone)-type polymer, an amorphous polymer, and a plasticizer, heating the resulting mixture, extruding or casting the mixture into a membrane, quenching or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, and/or after leaching.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: April 27, 1993
    Assignee: The Dow Chemical Company
    Inventors: Paul A. Damrow, Robert D. Mahoney, H. Nelson Beck, Mark F. Sonnenschein
  • Patent number: 5200078
    Abstract: The invention relates to a microporous membrane prepared from unsulfonated poly(etheretherketone)-type polymers.
    Type: Grant
    Filed: November 9, 1990
    Date of Patent: April 6, 1993
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Richard A. Lundgard, Robert D. Mahoney
  • Patent number: 5064580
    Abstract: A method of preparing a microporous membrane from unsulfonated poly(etheretherketone)-type polymers.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: November 12, 1991
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Richard A. Lundgard, Robert D. Mahoney
  • Patent number: 5015275
    Abstract: This invention relates to semi-permeable isotropic syndiotactic polystyrene microporous membranes and processes for preparing such membranes.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: May 14, 1991
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Robert D. Mahoney, Hawk S. Wan, Richard A. Lundgard
  • Patent number: 5013339
    Abstract: This invention relates a composition useful for preparing a polyvinylidene fluoride polymer membrane containing (1) a polyvinylidene fluoride polymer, (2) glycerol monoacetate, glycerol diacetate, glycerol triacetate, or mixtures thereof, and (3) optionally glycerol, wherein the polyvinylidene fluoride polymer membrane prepared from the composition is useful for a membrane liquid separation process such as microfiltration, ultrafiltration, dialysis, or membrane stripping. In another aspect, this invention is an improved process for using the composition to prepare a polyvinylidene fluoride polymer membrane by forming a mixture of the composition, heating the mixture to a temperature at which the mixture becomes a homogeneous fluid, and extruding, molding, or casting the homogeneous fluid into a membrane.
    Type: Grant
    Filed: December 5, 1989
    Date of Patent: May 7, 1991
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, Richard A. Lundgard
  • Patent number: 5011637
    Abstract: This invention relates to a novel composition useful for preparing a semi-permeable cellulose ester gas separation membrane, which composition includes a mixture of a cellulose ester, a solvent selected from the group consisting essentially of glycerol acetate, glycerol diacetate, glycerol triacetate, and mixtures thereof, and optionally the non-solvent glycerol. This invention also relates to a process of fabricating a cellulose ester gas separation membrane from said composition.
    Type: Grant
    Filed: January 23, 1989
    Date of Patent: April 30, 1991
    Assignee: The Dow Chemical Company
    Inventors: Dana C. Overman, III, Jee I. Kau, Robert D. Mahoney
  • Patent number: 4980063
    Abstract: This invention consists of a composition useful for preparing a cellulose ester membrane comprising (1) a cellulose ester, (2) glycerol monoacetate, glycerol diacetate, glycerol triacetate, or mixtures thereof, and (3) optionally glycerol, wherein the cellulose ester membrane prepared from said composition is useful for a membrane liquid separation process such as microfiltration, ultrafiltration, dialysis, or reverse osmosis. In another aspect, this invention is an improved process for using said composition to prepare a cellulose ester membrane by forming a mixture of said composition, heating the mixture to a temperature at which the mixture becomes a homogeneous fluid, and extruding, molding, or casting the homogeneous fluid into a membrane. Another aspect of this invention consists of a cellulose ester membrane wherein the fabricated membrane contains glycerol monoacetate, glycerol diacetate, glycerol triacetate, or mixtures thereof, and optionally glycerol.
    Type: Grant
    Filed: January 27, 1989
    Date of Patent: December 25, 1990
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, Jee I. Kau, Roger B. Hornby, Ernest A. Sharer
  • Patent number: 4980101
    Abstract: This invention relates to semi-permeable anisotropic syndiotatic polystyrene microporous membranes and a process for preparing such membranes.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: December 25, 1990
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Robert D. Mahoney, Hawk S. Wan, Richard A. Lundgard
  • Patent number: 4976901
    Abstract: This invention relates to novel semi-permeable isotropic or anisotropic microporous membranes fabricated from a mixture of isotactic polystyrene and syndiotactic polystyrene and a method of producing such membranes.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: December 11, 1990
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Robert D. Mahoney
  • Patent number: 4927535
    Abstract: This invention relates to novel semi-permeable isotropic or anisotropic microporous membranes fabricated from a mixture of isotactic polystyrene and syndiotactic polystyrene and a method of producing such membranes.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: May 22, 1990
    Assignee: The Dow Chemical Company
    Inventors: Henry N. Beck, Robert D. Mahoney
  • Patent number: 4543221
    Abstract: Improved cellulose semipermeable hollow fibers useful in detoxifying blood during hemodialysis or hemofiltration treatments. The cellulose fibers are fine, capillary fibers that are made by melt extrusion of certain cellulose ester polyol melt spin compositions into self-supporting gelled fibers. The cellulose ester gelled fibers are subsequently chemically converted into cellulose fibers by deacetylation, in aqueous alkali solution. The product fibers exhibit improved wet intrinsic tensile strength and higher water permeability characteristics than heretofore known cellulose fibers made from cellulose ester spin compositions.The invention includes the method of making the improved fibers and separatory cells such as hemodialyzers or hemofilters which contain the improved fibers in a gamma ray sterilized condition.
    Type: Grant
    Filed: October 21, 1981
    Date of Patent: September 24, 1985
    Assignee: CD Medical, Inc.
    Inventors: David T. Chen, Robert D. Mahoney
  • Patent number: 4276173
    Abstract: An improved cellulose acetate semi-permeable hollow fiber suitable for use in artificial kidneys and a process for making same.
    Type: Grant
    Filed: December 21, 1978
    Date of Patent: June 30, 1981
    Assignee: Cordis Dow Corp.
    Inventors: Michael J. Kell, Robert D. Mahoney
  • Patent number: 4115492
    Abstract: Normally hydrophobic, polyethylene hollow fibers having contiguous microporosity are prepared by extruding a heated solution of a polyethylene and an ester from a hollow fiber spinnerette, simultaneously cooling and drawing the forming fibers to a ratio of up to 40 to 1, drawing the gelled fibers to an overall ratio of from about 1.5/1 to 800/1 and then removing the ester. The maximum pore radius ranges up to about 50A, and the fibers have gas permeabilities approaching 10.sup.-2 cc (STP) per cm.sup.2 per second per cm. Hg. transmembrane pressure differential. A significant increase in permeability over polyethylene hollow fibers made according to the teachings of the prior art is achieved.
    Type: Grant
    Filed: January 28, 1977
    Date of Patent: September 19, 1978
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, Stephen E. Schneider
  • Patent number: 4020230
    Abstract: Normally hydrophobic, polyethylene hollow fibers having contiguous microporosity are prepared by extruding a heated solution of a polyethylene and an ester from a hollow fiber spinnerette, simultaneously cooling and drawing the forming fibers to a ratio of up to 40 to 1, drawing the gelled fibers to an overall ratio of from about 1.5/1 to 800/1 and then removing the ester. The maximum pore radius ranges up to about 50A, and the fibers have gas permeabilities approaching 10.sup.-.sup.2 cc (STP) per cm.sup.2 per second per cm. Hg. transmembrane pressure differential. A significant increase in permeability over polyethylene hollow fibers made according to the teachings of the prior art is achieved.
    Type: Grant
    Filed: October 3, 1975
    Date of Patent: April 26, 1977
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Mahoney, Stephen E. Schneider