Patents by Inventor David H. Dumas

David H. Dumas 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: 5176794
    Abstract: One or more layers of a sheet comprising (1) 60% to 99%, based on the weight of solids, of vermiculite delaminated by mechanical means only, (2) 1% to 40%, based on the weight of solids, of at least one fibrous material and (3) 0.1% to 4%, based on the weight of the vermiculite, of at least one flocculating agent, can be used to protect heat-sensitive substrates such as resin matrix composites from fire or heat.
    Type: Grant
    Filed: May 7, 1991
    Date of Patent: January 5, 1993
    Assignee: Hercules Incorporated
    Inventors: Herbert T. Conner, David H. Dumas, Lawrence L. Nelson
  • Patent number: 5139615
    Abstract: Disclosed is a process for making a composite sheet using papermaking techniques. The composite sheet comprises (1) 20% to 99%, based on the weight of solids, of vermiculite delaminated by mechanical shearing only, (2) 1% to 80%, based on the weight of solids, of at least one fibrous material and (3) 0.1% to 10%, based on the weight of the vermiculite, of at least one flocculating agent.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: August 18, 1992
    Assignee: Hercules Incorporated
    Inventors: Herbert T. Conner, David H. Dumas
  • Patent number: 4904520
    Abstract: Disclosed is a liquid-impermeable, gas-permeable nonwoven material comprising a thermally consolidated blend of (1) 5% to 30% of a first polyolefin pulp, (2) 15% to 90% of a second polyolefin pulp having a melting point at least 20.degree. C. higher than the first polyolefin pulp, and (3) 5% to 55% of a staple fiber. Also disclosed is a wet forming method for making such a nonwoven material without the use of surfactants.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: February 27, 1990
    Assignee: Hercules Incorporated
    Inventors: David H. Dumas, Elliott Echt
  • Patent number: 4522686
    Abstract: Described are sizing compositions in the form of aqueous dispersions comprising a hydrophobic cellulose-reactive sizing agent such as a ketene dimer, fortified rosin and a water-soluble, nitrogen-containing cationic dispersing agent. The compositions are highly efficient internal or surface sizing agents for paper and maximize the advantages of each sizing component while minimizing the disadvantages.
    Type: Grant
    Filed: July 7, 1983
    Date of Patent: June 11, 1985
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4478682
    Abstract: Disclosed is a method for sizing paper wherein the sizing agent employed is a hydrophobic cellulose reactive sizing agent such as a ketene dimer sizing agent. There is employed in combination with the sizing agent a novel sizing accelerator. Disclosed also is a novel sizing composition comprised of the sizing agent and the accelerator, the accelerator being a water-soluble nitrogen-containing reaction product of (1) a water-soluble polyaminopolyamide, such as that derived by reaction of adipic acid and diethylene-triamine; (2) an epihalohydrin, such as epichlorohydrin; and (3) a composition comprising, by weight, from about 20% to about 65% bis(hexamethylene)triamine, said composition being the residue obtained after recovery of hexamethylenediamine from its manufacture by hydrogenation of adiponitrile.
    Type: Grant
    Filed: September 21, 1982
    Date of Patent: October 23, 1984
    Assignee: Hercules Incorporated
    Inventors: Ralph A. Bankert, David H. Dumas
  • Patent number: 4407994
    Abstract: Disclosed is a method for sizing paper wherein the sizing agent employed is a hydrophobic cellulose reactive sizing agent such as a ketene dimer sizing agent. There is employed in combination with the sizing agent a novel sizing accelerator. Disclosed also is a novel sizing composition comprised of the sizing agent and the accelerator, the accelerator being a water-soluble nitrogen-containing reaction product of (1) a water-soluble polyaminopolyamide, such as that derived by reaction of adipic acid and diethylene-triamine; (2) an epihalohydrin, such as epichlorohydrin; and (3) a composition comprising, by weight, from about 20% to about 65% bis(hexamethylene)triamine, said composition being the residue obtained after recovery of hexamethylenediamine from its manufacture by hydrogenation of adiponitrile.
    Type: Grant
    Filed: July 2, 1981
    Date of Patent: October 4, 1983
    Assignee: Hercules Incorporated
    Inventors: Ralph A. Bankert, David H. Dumas
  • Patent number: 4380602
    Abstract: Disclosed are novel water-souble, thermosettable resinous compositions derived by reacting a precondensate of dicyandiamide, formaldehyde, a salt of a water-soluble polyaminopolyamide and an ammonium salt with epihalohydrin and then condensing the reaction product with additional formaldehyde. The resinous compositions are cationic and have particular utility in the manufacture of paper sized with cellulose reactive sizing agents such as ketene dimer sizing agents.
    Type: Grant
    Filed: December 8, 1981
    Date of Patent: April 19, 1983
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4317756
    Abstract: Disclosed is a sizing composition in the form of an aqueous emulsion comprising a hydrophobic cellulose-reactive sizing agent, such as a ketene dimer, and a cationic polymer selected from the group consisting of (1) a cationic polymer obtained by reacting an epihalohydrin with a condensate derived by condensing dicyandiamide or cyanamide with bis-aminopropylpiperazine and (2) a cationic polymer obtained by condensing an epihalohydrin with bis-aminopropylpiperazine. The cationic polymer is a sizing accelerator for the sizing agent.
    Type: Grant
    Filed: August 22, 1980
    Date of Patent: March 2, 1982
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4295931
    Abstract: Disclosed is a method for sizing paper wherein the sizing agent employed is a hydrophobic cellulose reactive sizing agent such as a ketene dimer sizing agent. There is employed in combination with the sizing agent a novel sizing accelerator whereby off-the-machine sizing is improved substantially. Disclosed also is a novel sizing composition comprised of the sizing agent and the accelerator, the accelerator being a poly(diallylamine)epihalohydrin resin.
    Type: Grant
    Filed: June 2, 1980
    Date of Patent: October 20, 1981
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4279794
    Abstract: Disclosed is a method for sizing paper wherein the sizing agent employed is a hydrophobic cellulose reactive sizing agent such as a ketene dimer sizing agent. There is employed in combination with the sizing agent a novel sizing accelerator whereby off-the-machine sizing is improved substantially. Disclosed also is a novel sizing composition comprised of the sizing agent and the accelerator, the accelerator being a poly(diallylamine)epihalohydrin resin.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: July 21, 1981
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4243481
    Abstract: Disclosed is a sizing composition in the form of an aqueous emulsion comprising a hydrophobic cellulose-reactive sizing agent, such as a ketene dimer, and a cationic polymer selected from the group consisting of (1) a cationic polymer obtained by reacting an epihalohydrin with a condensate derived by condensing dicyandiamide or cyanamide with bis-aminopropylpiperazine and (2) a cationic polymer obtained by condensing an epihalohydrin with bis-aminopropylpiperazine. The cationic polymer is a sizing accelerator for the sizing agent.
    Type: Grant
    Filed: August 9, 1978
    Date of Patent: January 6, 1981
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 4240935
    Abstract: Improved paper sizing compositions are composed of a ketene dimer, an anionic dispersing agent such as sodium lignin sulfonate, certain water-soluble, cationic resins and water. Exemplary of the cationic resins is the reaction product of epichlorohydrin and the aminopolyamide derived from adipic acid and diethylenetriamine.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: December 23, 1980
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 3992345
    Abstract: Disclosed are novel water-insoluble, water-dispersible thermosettable cationic resins derived by reaction of a diallylamine polymer, a hydrophobizing compound such as a ketene dimer and an epihalohydrin such as epichlorohydrin. The thermosettable cationic resins are water-dispersible, and aqueous dispersions thereof are stable for prolonged periods of time at relatively high solids concentration. The thermosettable cationic resins have particular utility in the sizing of paper.
    Type: Grant
    Filed: September 8, 1975
    Date of Patent: November 16, 1976
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: 3990939
    Abstract: Disclosed are novel water-insoluble, water-dispersible thermosettable cationic resins derived by reaction of a water-soluble aminopolyamide, a hydrophobizing compound such as a ketene dimer and an epihalohydrin such as epichlorohydrin. The thermosettable cationic resins are water-dispersible, and aqueous dispersions thereof are stable for prolonged periods of time at relatively high solids concentration. The thermosettable cationic resins have particular utility in the sizing of paper.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: November 9, 1976
    Assignee: Hercules Incorporated
    Inventors: Paul H. Aldrich, David H. Dumas
  • Patent number: 3989659
    Abstract: Disclosed are novel water-insoluble, water-dispersible thermosettable cationic resins derived by reaction of a water-soluble aminopolyamide, a hydrophobizing compound such as a ketone dimer and an epihalohydrin such as epichlorohydrin. The thermosettable cationic resins are water-dispersible, and aqueous dispersions thereof are stable for prolonged periods of time at relatively high solids concentration. The thermosettable cationic resins have particular utility in the sizing of paper.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: November 2, 1976
    Assignee: Hercules Incorporated
    Inventors: Paul H. Aldrich, David H. Dumas
  • Patent number: 3988280
    Abstract: Disclosed are novel water-insoluble, water-dispersible thermosettable cationic resins derived by reaction of a water-soluble aminopolyamide, a hydrophobizing compound such as a ketene dimer and an epihalohydrin such as epichlorohydrin. The thermosettable cationic resins are water-dispersible, and aqueous dispersions thereof are stable for prolonged periods of time at relatively high solids concentration. The thermosettable cationic resins have particular utility in the sizing of paper.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: October 26, 1976
    Assignee: Hercules Incorporated
    Inventors: Paul H. Aldrich, David H. Dumas
  • Patent number: 3968317
    Abstract: Disclosed are novel water-insoluble, water-dispersible thermosettable cationic resins derived by reaction of a diallylamine polymer, a hydrophobizing compound such as a ketene dimer and an epihalohydrin such as epichlorohydrin. The thermosettable cationic resins are water-dispersible, and aqueous dispersions thereof are stable for prolonged periods of time at relatively high solids concentration. The thermosettable cationic resins have particular utility in the sizing of paper.
    Type: Grant
    Filed: September 8, 1975
    Date of Patent: July 6, 1976
    Assignee: Hercules Incorporated
    Inventor: David H. Dumas
  • Patent number: T977009
    Abstract: disclosed is a paper-covered gypsum board comprised of a gypsum core and a paper cover sheet covering at least one side of said core, the surface of said paper cover sheet adjacent the gypsum core being surface sized with a sizing composition initially comprised of a hydrophobic cellulose reactive sizing agent and a nitrogen-containing condensation product.
    Type: Grant
    Filed: March 24, 1978
    Date of Patent: December 5, 1978
    Assignee: Hercules Incorporated
    Inventors: David H. Dumas, David R. Warren