Patents by Inventor David R. Gehman

David R. Gehman 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: 4477622
    Abstract: Disclosed are contact adhesives, containing aqueous polymeric latexes, particularly acrylic latexes. Contact adhesives are adhesives which dry to a non-tacky state but which will adhere to another surface of the same dried adhesive. A unique feature of the adhesives is that the polymer used therein has an extremely wide range of molecular weights with substantial proportions of the product having a low molecular weight and substantial portions having a very high molecular weight, preferably with fairly uniform progression from low molecular weight to high molecular weight. However, blends of a low molecular weight fraction and a high molecular weight polymer may also be used. The preferred procedure is to prepare an emulsion polymer by reacting part of the material in the reactor in such a way as to obtain a high molecular weight product and to react at least one other portion of the monomer in the same reactor in such a way as to obtain at least one low molecular weight fraction.
    Type: Grant
    Filed: September 11, 1981
    Date of Patent: October 16, 1984
    Assignee: Rohm and Haas Company
    Inventors: F. Thomas. Sanderson, David R. Gehman
  • Patent number: 4203859
    Abstract: As a modifier for carpet shampoos and the like, an aqueous composition containing a polymer component comprising an aqueous dispersion of an acrylic polymer, polyvalent metal ions, ammonia or a volatile amine to solubilize the copolymer, and optionally CO.sub.3 .dbd., HCO.sub.3.sup.-- or an anion of an amino acid. The acrylic polymer is a low molecular weight copolymer of 20-60 parts butyl acrylate, 0-25 parts styrene, 0-15 parts methyl methacrylate, and 40-60 parts of at least one of methacrylic acid, acrylic acid, and itaconic acid. Preferably the polymer contains at least about 5 parts of styrene, the styrene:butyl acrylate ratio being no more than 1:1. The pka of the polymer component is less than about 6.7 and the number average molecular weight of the polymer is about 2500-100,000. The viscosity in centipoises at 25% solids of polymer in water at C. and containing at least two equivalents of ammonium cation and at least 0.
    Type: Grant
    Filed: April 21, 1978
    Date of Patent: May 20, 1980
    Assignee: Rohm and Haas Company
    Inventors: William A. Kirn, David R. Gehman
  • Patent number: 4196190
    Abstract: Acrylic polymer solutions having superior properties when used as hair setting or holding resins are disclosed. Specific polymers disclosed are derived from (1) alkyl acrylates with 2-8 carbon alkyl groups, (2) methyl methacrylate, (3) hydroxyethyl methacrylate, and (4) methacrylic acid in proportions yielding a film forming resin readily soluble in shampoo, with a Tg between about C. and C., a molecular weight between about 25,000 and 250,000 and not more than 50 ppm of unreacted alkyl acrylate monomer.
    Type: Grant
    Filed: January 9, 1978
    Date of Patent: April 1, 1980
    Assignee: Rohm and Haas Company
    Inventors: David R. Gehman, William A. Kirn
  • Patent number: 4168255
    Abstract: This invention discloses the composition and use of salts of low molecular weight polymers of methacrylic and acrylic esters formulated with wetting, emulsifying, plasticizing or coalescing agents as aqueous finish compositions for hard surfaces. The polymers have molecular weights between 700 and 5000 and acid numbers between 50 and 275. The finishes produced by the compositions are water clear and are self-dispersible. Thus, on reapplication, the previous film is dissolved, the embedded soil removed and a fresh film left.
    Type: Grant
    Filed: April 13, 1976
    Date of Patent: September 18, 1979
    Assignee: Rohm and Haas Company
    Inventors: Sheldon N. Lewis, Richard A. Haggard, David R. Gehman
  • Patent number: 4150005
    Abstract: This invention relates to a latex of internally plasticized polymer particles, low in viscosity although high in hydrophilic components and film forming at temperatures below the calculated Tg of the polymer. The polymer may be prepared by a multistage emulsion polymerization process. The first stage is highly water-swellable or water-soluble. The principal second or later stage is less hydrophilic and of higher Tg than the first stage and is polymerized in the emulsion in the presence of the first stage.
    Type: Grant
    Filed: February 9, 1978
    Date of Patent: April 17, 1979
    Assignee: Rohm and Haas Company
    Inventors: David R. Gehman, Joseph M. Owens, Richard E. Zdanowski
  • Patent number: 4022730
    Abstract: A method for leveling latex polishes which comprises treating said polishes with a salt of partially hydrolyzed polymer of methacrylic ester wherein said polymer has an average chain length of from about 6 to about 20 mer units.
    Type: Grant
    Filed: October 21, 1974
    Date of Patent: May 10, 1977
    Assignee: Rohm and Haas Company
    Inventors: Sheldon N. Lewis, David R. Gehman, Richard A. Haggard
  • Patent number: 4017662
    Abstract: This invention relates to essentially water-clear aqueous coating compositions, particularly floor polishing compositions, containing a highly hydrophilic addition copolymer of low molecular weight, a water miscible organic coalescing agent or plasticizer and, as optional components, a polyvalent metal compound, an alkali-soluble resin and a wax, with or without a wax-soluble resin. Methods of using the composition and articles containing transparent coatings derived from such compositions are also included in the invention. The compositions of this invention, when formulated with such desirable additives as wetting agents and leveling agents and adjusted to a final alkaline pH of between 7.
    Type: Grant
    Filed: January 24, 1972
    Date of Patent: April 12, 1977
    Assignee: Rohm and Haas Company
    Inventors: David R. Gehman, Irwin S. Fiarman