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).
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Patent number: 5176794Abstract: 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: GrantFiled: May 7, 1991Date of Patent: January 5, 1993Assignee: Hercules IncorporatedInventors: Herbert T. Conner, David H. Dumas, Lawrence L. Nelson
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Patent number: 5139615Abstract: 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: GrantFiled: December 28, 1988Date of Patent: August 18, 1992Assignee: Hercules IncorporatedInventors: Herbert T. Conner, David H. Dumas
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Patent number: 4904520Abstract: 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: GrantFiled: October 17, 1988Date of Patent: February 27, 1990Assignee: Hercules IncorporatedInventors: David H. Dumas, Elliott Echt
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Patent number: 4522686Abstract: 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: GrantFiled: July 7, 1983Date of Patent: June 11, 1985Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4478682Abstract: 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: GrantFiled: September 21, 1982Date of Patent: October 23, 1984Assignee: Hercules IncorporatedInventors: Ralph A. Bankert, David H. Dumas
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Patent number: 4407994Abstract: 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: GrantFiled: July 2, 1981Date of Patent: October 4, 1983Assignee: Hercules IncorporatedInventors: Ralph A. Bankert, David H. Dumas
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Patent number: 4380602Abstract: 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: GrantFiled: December 8, 1981Date of Patent: April 19, 1983Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4317756Abstract: 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: GrantFiled: August 22, 1980Date of Patent: March 2, 1982Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4295931Abstract: 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: GrantFiled: June 2, 1980Date of Patent: October 20, 1981Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4279794Abstract: 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: GrantFiled: December 26, 1979Date of Patent: July 21, 1981Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4243481Abstract: 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: GrantFiled: August 9, 1978Date of Patent: January 6, 1981Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 4240935Abstract: 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: GrantFiled: December 22, 1978Date of Patent: December 23, 1980Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 3992345Abstract: 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: GrantFiled: September 8, 1975Date of Patent: November 16, 1976Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: 3990939Abstract: 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: GrantFiled: April 28, 1975Date of Patent: November 9, 1976Assignee: Hercules IncorporatedInventors: Paul H. Aldrich, David H. Dumas
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Patent number: 3989659Abstract: 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: GrantFiled: April 28, 1975Date of Patent: November 2, 1976Assignee: Hercules IncorporatedInventors: Paul H. Aldrich, David H. Dumas
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Patent number: 3988280Abstract: 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: GrantFiled: April 28, 1975Date of Patent: October 26, 1976Assignee: Hercules IncorporatedInventors: Paul H. Aldrich, David H. Dumas
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Patent number: 3968317Abstract: 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: GrantFiled: September 8, 1975Date of Patent: July 6, 1976Assignee: Hercules IncorporatedInventor: David H. Dumas
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Patent number: T977009Abstract: 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: GrantFiled: March 24, 1978Date of Patent: December 5, 1978Assignee: Hercules IncorporatedInventors: David H. Dumas, David R. Warren