Patents Represented by Attorney Thomas A. Ladd
  • Patent number: 5633316
    Abstract: The invention is surface crosslinked particles of water absorbing resin comprising particles of a carboxyl containing water-absorbent resin; wherein the particles of the carboxyl containing water-absorbent resin are crosslinked at or near the particle surface by a polyhydroxy compound capable of reacting with the carboxyl moieties of the water-absorbent resin, and the particles have coated on or bound to the surface a nonionic surfactant having an HLB of from 3 to 10.Additionally a process for the preparation of such surface crosslinked and surfactant coated absorbent resin particles is disclosed. Further disclosed is a water-absorbent structure comprising a synthetic or natural fiber or paper based woven or nonwoven carrier structure and surface crosslinked and surfactant coated water-absorbent resin particles of this invention.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: May 27, 1997
    Assignee: The Dow Chemical Company
    Inventors: Herbert Gartner, Josef Burgert
  • Patent number: 5378743
    Abstract: This invention relates to a stable, low level styrene emission vinyl ester or unsaturated polyester resin composition containing a nonionic surfactant or a copolymer of maleic acid half ester of a polyethylene glycol and a monoalkenyl aromatic monomer as stabilizing agents.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: January 3, 1995
    Assignee: The Dow Chemical Company
    Inventor: Rolf F. Liedtke
  • Patent number: 5198112
    Abstract: A composite membrane suitable for separations of fluid components by electropolymerization of a discrimination layer on an electrically conductive porous support.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: March 30, 1993
    Assignee: The Dow Chemical Company
    Inventors: Charles R. Martin, Mark W. Espenscheid
  • Patent number: 5056210
    Abstract: A method of securing a loose polymeric resilient liner to a rigid pipe to permit flaring of the polymeric liner to form a flange joint interface. Apparatus to secure the resilient liner while the polymer liner is flared is also disclosed.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: October 15, 1991
    Assignee: The Dow Chemical Company
    Inventor: Howard W. King, Jr.
  • Patent number: 4992485
    Abstract: A microporous polyetheretherketone (PEEK) membrane in the form of films and hollow fibers formed without sulfonating the PEEK polymer. Solid fibers and articles are also claimed. A method of making membranes, fibers and articles from solutions of PEEK in non-sulfonating acid solvents in claimed. Solvents include methane sulfonic acid and trifluoromethane sulfonic acid. Sulfuric acid may be used as a diluent in non-sulfonating amounts. PEEK membranes are used as supports for composite ultrafiltration and reverse osmosis membranes. A method of making membranes, fibers, and articles is also described.
    Type: Grant
    Filed: October 11, 1988
    Date of Patent: February 12, 1991
    Assignees: The Dow Chemical Company, Filmtec Corporation
    Inventors: Ja-Young Koo, Chieh-Chun Chau, Joel R. Racchini, Ritchie A. Wessling, Matthew T. Bishop
  • Patent number: 4973514
    Abstract: A resinous composite material is disclosed containing randomly dispersed fibers and from about 0.05 to 30 percent of a particulate conductive or semi-conductive filler. In addition to providing excellent EMI shielding properties, these composites are formable and are of sufficient strength to act as structural components.
    Type: Grant
    Filed: June 11, 1984
    Date of Patent: November 27, 1990
    Assignee: The Dow Chemical Company
    Inventors: Jeffrey Gamble, Larry D. Yats
  • Patent number: 4957817
    Abstract: High boiling point polar organic solvent are useful solvents for poly(etheretherketone)-type polymers (PEEK). Solutions of PEEK may be used to form PEEK articles such as film, microporous sheet membrane, fiber and microporous hollow fibers. The microporous PEEK is useful as an ultrafiltration membrane and as a substrate for the formation of reverse osmosis membranes. A method of making PEEK articles including microporous sheet membranes is disclosed. A method of making PEEK fibers including microporous hollow membrane fibers is disclosed.
    Type: Grant
    Filed: November 25, 1988
    Date of Patent: September 18, 1990
    Assignee: The Dow Chemical
    Inventors: Chieh-Chun Chau, Ritchie A. Wessling
  • Patent number: 4927540
    Abstract: A reverse osmosis membrane bearing an ionic complex and a method of making the membrane is described. The ionic complex is formed from a first compound bearing at least one quaternary ammonium or pyridinium group and a second compound bearing at least one sulfonate or carboxylate group. The complex enhances solute rejection of the membrane.
    Type: Grant
    Filed: April 19, 1988
    Date of Patent: May 22, 1990
    Assignee: The Dow Chemical Company
    Inventors: Ritchie A. Wessling, Sharon S. Whipple, Richard F. Fibiger
  • Patent number: 4921658
    Abstract: A process for preparing reinforced thermoset articles of manufacture from a lofted composite sheet employed as a skeleton or preform which is impregnated with a thermoset resin composition and cured. A reinforced thermoset article of manufacture prepared from a lofted composite impregnated with a thermoset resin composition and cured is also provided.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: May 1, 1990
    Assignee: The Dow Chemical Company
    Inventors: Donald W. Pennington, Jane K. McLemore
  • Patent number: 4904385
    Abstract: A method for filtering liquid or gaseous materials where the filtration is conducted with a porous filter media prepared from an aqueous wet-laid, lofted fiber-reinforced composite sheet, the composite sheet comprising a heat fusible polymer, reinforcing fibers and a binder. The random fiber composite sheet can be selectively lofted or recompressed to form filter media having variable porosity. Also, a membrane support means prepared by applying or treating the fiber-reinforced composite sheet with a discriminating membrane layer.
    Type: Grant
    Filed: May 19, 1988
    Date of Patent: February 27, 1990
    Assignee: The Dow Chemical Company
    Inventors: Ritchie A. Wessling, Larry D. Yats, Alan F. Burmester
  • Patent number: 4872709
    Abstract: A toggle clamp is fitted with opposed pipe flange engaging jaws and provides a rapid means of alignment and positioning of flanged pipe during assembly; particularly suited for use with split "V" clamp joints.
    Type: Grant
    Filed: May 2, 1983
    Date of Patent: October 10, 1989
    Assignee: The Dow Chemical Company
    Inventor: Eugene V. Stack
  • Patent number: 4820406
    Abstract: The froth flotation of coal is conducted in the presence of an epoxide conditioner.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: April 11, 1989
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Hansen, Richard R. Klimpel
  • Patent number: 4797187
    Abstract: A novel composite membrane and methods of making the membrane are described. The discriminating layer of the membrane is prepared by reaction of a reactive cationic compound group with a compound bearing a nucleophilic moiety. At least one of the reactants bears an average of two or more reactive groups. The reaction product contains covalent bonds formed via charge eliminating reactions.In a preferred embodiment of the invention, the nucleophilic group is anionic and a coacervate is formed initially on a microporous substrate. The resulting membrane may be useful for reverse osmosis, gas or ultrafiltration separations.
    Type: Grant
    Filed: August 17, 1987
    Date of Patent: January 10, 1989
    Assignee: The Dow Chemical Company
    Inventors: Thomas E. Davis, Donald L. Schmidt, Jee I. Kau, Ritchie A. Wessling, Sharon S. Whipple, Richard F. Fibiger, Dale M. Pickelman
  • Patent number: 4778615
    Abstract: An inorganic halide and a water soluble hydroxy-containing organic compound or urea are useful in treating particulate solids such that the solids are more easily dumped after being exposed to freezing temperatures. The combination of the inorganic halide and hydroxy-containing organic compound or urea not only reduce the strength of ice formed between the particles but also reduce the amount of particulate solids which sticks to the sides of the transport or storage container from which the solids are removed.
    Type: Grant
    Filed: September 9, 1986
    Date of Patent: October 18, 1988
    Assignee: The Dow Chemical Company
    Inventor: Michael F. Jeglic