Patents by Inventor Dwight K. Hoffman
Dwight K. Hoffman 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: 6613816Abstract: In one embodiment the invention is An adhesive composition comprising a) a polymer having a flexible backbone and a reactive moiety capable of cross-linking, b) a particle comprising an active agent encapsulated in an encapsulating agent wherein the active agent comprises a catalyst for cross-linking of the reactive moiety, a curing agent for the reactive moiety, an accelerator for the curing reaction or a mixture thereof; and the encapsulating agent comprises a side chain crystallizable polymer wherein the active agent is not substantially extractable from the particle at ambient conditions in a first extraction after particle formation.Type: GrantFiled: June 7, 2001Date of Patent: September 2, 2003Assignee: The Dow Chemical CompanyInventors: Syed Z. Mahdi, Renhe R. Lin, Dwight K. Hoffman, Gordon M. Parker, Harry W. Hsieh
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Patent number: 6355127Abstract: In one embodiment the invention is An adhesive composition comprising a) a polymer having a flexible backbone and a reactive moiety capable of cross-linking, b) a particle comprising an active agent encapsulated in an encapsulating agent wherein the active agent comprises a catalyst for cross-linking of the reactive moiety, a curing agent for the reactive moiety, an accelerator for the curing reaction or a mixture thereof; and the encapsulating agent comprises a side chain crystallizable polymer wherein the active agent is not substantially extractable from the particle at ambient conditions in a first extraction after particle formation. This composition is used in binding two subtracters together.Type: GrantFiled: April 27, 1999Date of Patent: March 12, 2002Assignees: The Dow Chemical Company, Essex Specialty Products, Inc.Inventors: Syed Z. Mahdi, Renhe R. Lin, Dwight K. Hoffman, Gordon M. Parker, by Michael Parker, Harry W. Hsieh
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Publication number: 20020010272Abstract: In one embodiment the invention is An adhesive composition comprisingType: ApplicationFiled: June 7, 2001Publication date: January 24, 2002Inventors: Syed Z. Mahdi, Renhe R. Lin, Dwight K. Hoffman, Gordon M. Parker, Harry W. Hsieh, Michael Parker
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Patent number: 6277903Abstract: The invention is a sprayable coating having noise vibration and harshness reduction or absorption properties. Such composition comprises from about 10 to about 60 percent of the flexible epoxy resin, from about 5 to about 40 percent by weight of a rigid epoxy resin formulation, and a curing agent for the epoxy moieties of the two resins. In another embodiment, the invention is a method of coating a substrate to reduce the impact of noise vibration and harshness on the substrate or users of the substrate, which process comprises spraying the above defined composition on to a substrate and curing the resin on such substrate. In yet another embodiment the invention is a coated substrate described herein before having enhanced noise vibration and harshness properties.Type: GrantFiled: September 21, 1998Date of Patent: August 21, 2001Assignees: The Dow Chemical Company, Essex Specialty Products, Inc.Inventors: Daniel P. Sophiea, Dwight K. Hoffman, Xiao Hong, Gloria Hsu
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Patent number: 6224793Abstract: The invention is an encapsulated active agent comprising an active agent encapsulated in a crystallizable or thermoplastic polymer wherein the particle size of the encapsulated active agent is 3,000 microns or less wherein the active agent is not significantly extractable from the particles under ambient conditions. In another embodiment the invention is a process for preparing an encapsulated agent which comprises a) contacting an active agent with a crystallizable or thermoplastic polymer wherein the polymer is molten and the active agent in not volatile under the contacting conditions; b) forming particles of about 3000 microns or less; and c) exposing the particles to conditions such that the portion of the particle at and near the surface undergoes rapid solidification. The encapsulated active agents of the invention do not require washing in order for them to be stable in curable compositions. These encapsulated active agents can be designed to release the active agent at a desired temperature.Type: GrantFiled: April 27, 1999Date of Patent: May 1, 2001Assignees: The Dow Chemical Company, Landec CorporationInventors: Dwight K. Hoffman, Steven P. Bitler
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Patent number: 6133398Abstract: The present invention is a one-part adhesive composition comprising:A) an isocyanate functional polyurethane prepolymer;B) a catalyst capable of catalyzing the reaction of isocyanate moieties with an isocyanate reactive compound;C) particles comprising a curing agent for an isocyanate functional. polyurethane prepolymer encapsulated within a coating material;wherein the prepolymer has a free isocyanate content of from about 0.8 to about 2.2 percent. In another embodiment the invention is a process for bonding two substrates together which comprises rupturing the encapsulated curing agent particles so as to contact the curing agent with the prepolymer in the adhesive composition, contacting the adhesive composition of the invention with at least one of the substrates and contacting the substrates together along the portion of the substrate(s) to which the adhesive has been applied before the adhesive applied cures and allowing the adhesive to cure and bond the substrates together.Type: GrantFiled: April 13, 1999Date of Patent: October 17, 2000Assignee: The Dow Chemical CompanyInventors: Shailesh S. Bhat, Sidky D. Rizk, Dwight K. Hoffman
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Patent number: 5601761Abstract: An active material encapsulated in a coating material immiscible therewith is contacted with a solvent that dissolves residual active material on the surface of the coating material without dissolving the coating material. The resultant encapsulated material has improved stability as compared to the material not contacted with solvent.Type: GrantFiled: September 26, 1994Date of Patent: February 11, 1997Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, David V. Dellar, Herman W. Schlameus
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Patent number: 5461106Abstract: A solid polymeric latent initiator which is a dehydrated aqueous emulsion polymer of a monomer having an ethylenically unsaturated group and an organic salt group, the salt group being a product of an acid and a base, wherein either the acid or the base or the acid and the base are initiators capable of opening a strained heterocyclic ring system, provides rapid cure-on-demand one-part adhesives with improved shelf stability.Type: GrantFiled: December 12, 1994Date of Patent: October 24, 1995Assignee: The Dow Chemical CompanyInventors: Gary L. Jialanella, Dwight K. Hoffman
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Patent number: 5204386Abstract: A thixoropic adhesive composition exhibiing good sag resistance is prepared comprising a mixture of a polymer-modified epoxy resin and a rheological control agent. The polymer-modified epoxy resin is preferably a dispersion of acrylic elastomer in an epoxy resin in which the acrylic elastomer particles have added hydroxyl functionality which interacts favorably with rheological control agents, such as fumed silica. Acrylic epoxy resin dispersions containing added hydroxyl functionality give improved rheological control.Type: GrantFiled: June 9, 1992Date of Patent: April 20, 1993Assignee: The Dow Chemical CompanyInventors: Yasemin Ersun-Hallsby, Dwight K. Hoffman, Gerald C. Kolb, Gene D. Rose
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Patent number: 5055532Abstract: Vinylized epoxy resins, such as vinyl ester resins, comprise polymerizable ethylenic unsaturation and an in situ polymerized polymer, such as a polyalkyl acrylate. The vinylized epoxy resins can form stable dispersions and are useful in thermoset applications.Type: GrantFiled: July 6, 1987Date of Patent: October 8, 1991Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Virginia B. Messick, Michael G. Stevens
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Patent number: 4798877Abstract: Novel radiation-curable, water-compatible, resinous compositions result from (1) terminally unsaturated molecules which are the esters of an epoxy compound and (2) the reaction product of a glycidyl ether and an unsaturated acid having at least one glycidyl group per molecule converted to an onium salt of a quaternary ammonium or amine salt, with the anion of an inorganic or organic acid.Type: GrantFiled: April 8, 1985Date of Patent: January 17, 1989Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Robert F. Harris, Richard A. Hickner
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Patent number: 4789712Abstract: Dispersions of polymers and optional dispersion stabilizers in a polyepoxide resin continuous phase is characterized in that the dispersion remains stable above 60.degree. C. The compositions are curable and are useful as coatings, in preparing laminates and reinforced plastics, and as adhesives. The compositions exhibit properties which are superior to compositions containing reactive liquid polymers.Type: GrantFiled: August 10, 1987Date of Patent: December 6, 1988Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Charles B. Arends
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Patent number: 4745153Abstract: This invention is a process for preparing a polymer polyol comprising the steps of(a) forming in a first step a dispersant by homopolymerizing a vinyl-terminated adduct, or copolymerizing said adduct with an ethylenically unsaturated monomer or mixture thereof which is not a vinyl-terminated adduct, in the presence of an active hydrogen-containing compound as a solvent under conditions such that the resulting dispersant is soluble in a base polyol, and has a Brookfield viscosity of less than about 25,000 centipoises as a 20-35 wt. -% solution in an active hydrogen-containing compound, and(b) polymerizing an ethylenically unsaturated monomer or mixture thereof in the presence of said dispersant and a base polyol under conditions such that the polymerized monomer forms a plurality and particles which are stabilized against agglomeration by the dispersant.Type: GrantFiled: December 17, 1986Date of Patent: May 17, 1988Assignee: The Dow Chemical CompanyInventor: Dwight K. Hoffman
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Patent number: 4708996Abstract: Dispersions of polymers and optional dispersion stabilizers in a polyepoxide resin continuous phase is characterized in that the dispersion remains stable above 60.degree. C. The compositions are curable and are useful as coatings, in preparing laminates and reinforced plastics, and as adhesives. The compositions exhibit properties which are superior to compositions containing reactive liquid polymers.Type: GrantFiled: October 25, 1984Date of Patent: November 24, 1987Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Charles B. Arends
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Patent number: 4707529Abstract: Dispersions of siloxane polymers and optional dispersion stabilizers in a polyepoxide resin continuous phase are characterized in that the siloxane polymer is grafted to the polyepoxide resin, and the dispersions remain stable. The compositions are curable and are useful as coatings, in preparing laminates and reinforced plastics, and as adhesives.Type: GrantFiled: June 27, 1985Date of Patent: November 17, 1987Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Reet T. Fernandez
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Patent number: 4690988Abstract: Vinylized epoxy resins, such as vinyl ester resins, comprise polymerizable ethylenic unsaturation and an in situ polymerized polymer, such as a polyalkyl acrylate. The vinylized epoxy resins can form stable dispersions and are useful in thermoset applications.Type: GrantFiled: January 22, 1985Date of Patent: September 1, 1987Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Michael G. Stevens, Virginia B. Messick
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Patent number: 4640935Abstract: An adduct of a heteroatomic monomer, e.g., gamma-methacryloxypropyl trimethoxysilane and a monoahl, e.g., a monohydroxyl polyalkylene oxide or a polyahl, e.g., a polypropylene glycol, is usefully employed in the preparation of stable copolymer dispersions of the type used in the production of polyurethane foams and polyurethane elastomers.The copolymer dispersion is prepared by addition copolymerization of (1) the adduct with (2) ethylenically unsaturated monomer(s), e.g., styrene or mixture thereof with acrylonitrile, while (1) and (2) are dispersed or dissolved in an excess of a polyahl, i.e., an active hydrogen polyfunctional compound.Type: GrantFiled: May 9, 1985Date of Patent: February 3, 1987Assignee: The Dow Chemical CompanyInventors: Thomas E. Fisk, Dwight K. Hoffman
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Patent number: 4588830Abstract: An adduct of a heteroatomic monomer, e.g., gamma-methacryloxypropyl trimethoxysilane and a monoahl, e.g., a monohydroxyl polyalkylene oxide or a polyahl, e.g., a polypropylene glycol, is usefully employed in the preparation of stable copolymer dispersions of the type used in the production of polyurethane foams and polyurethane elastomers.The copolymer dispersion is prepared by addition copolymerization of (1) the adduct with (2) ethylenically unsaturated monomer(s), e.g., styrene or mixture thereof with acrylonitrile, while (1) and (2) are dispersed or dissolved in an excess of a polyahl, i.e., an active hydrogen polyfunctional compound.Type: GrantFiled: December 9, 1982Date of Patent: May 13, 1986Assignee: The Dow Chemical CompanyInventors: Thomas E. Fisk, Dwight K. Hoffman
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Patent number: 4513124Abstract: An adduct of a monoahl, e.g., a monohydroxyl polyalkylene oxide, and an active ethylenically unsaturated coreactant monomer, methacryloyl chloride, is usefully employed in the preparation of stable copolymer dispersions of the type used in the production of polyurethane foams and polyurethane elastomers.The copolymer dispersion is prepared by addition copolymerization of (1) the adduct with (2) ethylenically unsaturated monomers(s), e.g., styrene or mixture thereof with acrylonitrile, while (1) and (2) are dispersed or dissolved in an excess of an active hydrogen polyfunctional compound.Type: GrantFiled: February 14, 1983Date of Patent: April 23, 1985Assignee: The Dow Chemical CompanyInventor: Dwight K. Hoffman
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Patent number: 4460715Abstract: A stable copolymer dispersion is prepared by addition copolymerization of (1) a monomeric adduct of an active hydrogen compound, e.g., a polyether polyol, and an acrylyl compound such as methacryloyl chloride with (2) ethylenically unsaturated monomer(s), e.g., styrene or a mixture thereof with acrylonitrile, while (1) and (2) are dispersed or dissolved in an excess of an active hydrogen polyfunctional compound such as a polyether polyol. The molar ratio of acrylyl moiety to active hydrogen compound is less than 0.1:1. The resulting dispersion has a controlled particle size and a viscosity such that it is suitably employed in the production of polyurethane foams.Type: GrantFiled: November 10, 1981Date of Patent: July 17, 1984Assignee: The Dow Chemical CompanyInventors: Dwight K. Hoffman, Robert F. Harris, Nancy B. Tefertiller, Randall C. Rains