Patents by Inventor Dustin H. Thomas
Dustin H. Thomas 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: 7999118Abstract: This invention provides a process for the N-halogenation of at least one 5-hydrocarbyl hydantoin and/or at least one 5,5-dihydrocarbyl hydantoin. The process comprises concurrently feeding into a reaction zone (i) water, inorganic base, and 5,5-dimethylhydantoin, these being fed separately and/or in any combination(s), (ii) a separate feed of a brominating agent, and (iii) a separate feed of a chlorinating agent, in proportions such that during all or substantially all of the time the concurrent feeding is occurring halogenation of the 5-hydrocarbyl hydantoin and/or 5,5-dihydrocarbyl hydantoin occurs and resultant halogenated product precipitates in the liquid phase of an aqueous reaction mixture, and in which the pH of the liquid phase is continuously or substantially continuously maintained in the range of about 2.0 to about 8.0 during all or substantially all of the time the concurrent feeding is occurring.Type: GrantFiled: October 17, 2005Date of Patent: August 16, 2011Assignee: Albemarle CorporationInventors: Hassan Y. Elnagar, Bruce C. Peters, Edgar E. Spielman, Jr., Dustin H. Thomas
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Patent number: 6809205Abstract: The process enables highly effective N-halogenation of a compound having one or more halogenatable amido or imido functional groups in the molecule. The process involves, for example, concurrently feeding into a reactor (i) water, inorganic base, and the compound to be N-halogenated, e.g., a hydantoin, and a feed of (ii) a brominating agent and/or a chlorinating agent. The proportions of these feeds are such that the pH is kept within the range of ca. 5.5-8.5 (preferably 6.5-8.5, and most preferably 6.8-7.2) and one or more of the amido or imido nitrogen atoms is substituted by a bromine or chlorine atom. A feature of the process is that it can be conducted at elevated temperatures as high as about 90° C. without appreciable thermal decomposition of reactants or product. The resultant product continuously precipitates in high yield and purity. Moreover, products can be produced that are very pale yellow to almost pure white in appearance.Type: GrantFiled: January 18, 2000Date of Patent: October 26, 2004Assignee: Albemarle CorporationInventors: Hassan Y. Elnagar, Bruce C. Peters, Edgar E. Spielman, Jr., Dustin H. Thomas
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Patent number: 6508954Abstract: Among the enhanced properties of the 1,3-dibromo-5,5-dimethylhydantoins described are their larger average particle sizes, their compactibility even though devoid of a binder, their excellent free-flowing and low-dust properties, and their more appealing aesthetic qualities, as compared to previously known 1,3-dibromo-5,5-dimethylhydantoins. These novel 1,3-dibromo-5,5-dimethylhydantoins can be produced, for example, by concurrently feeding (i) an aqueous solution or slurry formed from an inorganic base and 5,5-dimethylhydantoin, and (ii) a brominating agent, in proportions such that each nitrogen atom is substituted by a bromine atom, thereby forming product which precipitates in an aqueous reaction mixture. The pH of the reaction mixture is maintained in the range of about 5.5 to about 8.5.Type: GrantFiled: January 18, 2000Date of Patent: January 21, 2003Assignee: Albemarle CorporationInventors: Hassan Y. Elnagar, Jonathan N. Howarth, Bruce C. Peters, Edgar E. Spielman, Jr., Dustin H. Thomas
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Patent number: 6281176Abstract: This invention provides a process for producing a betaine/amine oxide mixture. This process comprises reacting, in a liquid medium, an alkali metal &ohgr;-halocarboxylate with a first tertiary amine of the formula Ra2RbN, wherein each Ra group is a hydrocarbyl group which independently has from 1 to about 4 carbon atoms, and wherein the Rb group is a hydrocarbyl group which has from about 8 to about 24 carbon atoms, to produce a betaine product solution. To the betaine product solution is added a second tertiary amine of the formula Ra2RbN, wherein each Ra group is a hydrocarbyl group which independently has from 1 to about 4 carbon atoms, and wherein the Rb group is a hydrocarbyl group which has from about 8 to about 24 carbon atoms, to produce an amine/betaine mixture. The first and second tertiary amines can be separate portions of the same amine. Preferably, however, the first and second tertiary amines differ from each other.Type: GrantFiled: December 3, 1999Date of Patent: August 28, 2001Assignee: Albemarle CorporationInventors: Rebecca S. Cochran, Patrick C. Hu, Michael S. McCaig, Edmund F. Perkins, Jr., Joe D. Sauer, Dustin H. Thomas
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Patent number: 6166255Abstract: Exothermic oxidation of tertiary amine with aqueous hydrogen peroxide in an aqueous reaction medium formed or being formed from tertiary amine, aqueous hydrogen peroxide, carbon dioxide, and optionally chelating agent and/or additional water, is initiated at about 15 to about 25.degree. C., and while agitating the reaction mixture, the temperature is allowed to rise adiabatically to a temperature in the range of about 50 to about 100.degree. C. In this way, it is possible to produce tertiary amine oxides with very low levels, if any, of nitrosamine impurity, without addition of metal and/or phosphorus-containing components recommended in the prior art. Even though a substantial portion of the reaction is performed at temperatures in the range of about 50-100.degree. C., nitrosamine content, if any, in the resultant tertiary amine oxide product can be well below 30 ppb, and the free amine content, if any, can be well below 0.3 wt %.Type: GrantFiled: September 11, 1998Date of Patent: December 26, 2000Assignee: Albemarle CorporationInventors: Rebecca S. Cochran, Andrea P. Wight, Douglas H. Krzystowczyk, Dustin H. Thomas
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Patent number: 6080889Abstract: Exothermic oxidation of tertiary amine with aqueous hydrogen peroxide in an aqueous reaction medium formed or being formed from tertiary amine, aqueous hydrogen peroxide, carbon dioxide, and optionally chelating agent and/or additional water, is initiated at about 15 to about 25.degree. C., and while agitating the reaction mixture, the temperature is allowed to rise adiabatically to a temperature in the range of about 50 to about 100.degree. C. In this way, it is possible to produce tertiary amine oxides with very low levels, if any, of nitrosamine impurity, without addition of metal and/or phosphorus-containing components recommended in the prior art. Even though a substantial portion of the reaction is performed at temperatures in the range of about 50-100.degree. C., nitrosamine content, if any, in the resultant tertiary amine oxide product can be well below 30 ppb.Type: GrantFiled: April 1, 1998Date of Patent: June 27, 2000Assignee: Albemarle CorporationInventors: Rebecca S. Cochran, Andrea P. Wight, Douglas H. Krzystowczyk, Dustin H. Thomas
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Patent number: 6037497Abstract: A process is described in which tertiary amine is oxidized with hydrogen peroxide in the presence of carbon dioxide until the reaction mass contains (i) about 0.5 to about 6.5%, and preferably about 1 to about 2.5%, of unreacted free amine, (ii) carbon dioxide, and (iii) unreacted hydrogen peroxide. At this point individual portions of the reaction mass are dispensed into a plurality of shipping containers, or alternatively, the reaction mass is transferred to a cooling vessel, cooled therein, and then dispensed into a plurality of shipping containers. Thereafter the reaction is allowed to slowly continue to completion at ambient temperature in the shipping containers with venting of off-gases, as required. The process makes it possible to produce amine oxides with increased plant throughput without need for additional plant reaction equipment such as glass-lined reactors, and the consequent substantial additional capital investment.Type: GrantFiled: September 29, 1998Date of Patent: March 14, 2000Assignee: Albemarle CorporationInventors: Dustin H. Thomas, Douglas H. Krzystowczyk, Luc G. Six
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Patent number: 5593619Abstract: This invention relates to compositions containing improved granulated hexabromocyclododecane flame retardant products, flame retardant formulations containing products, and to a process for forming the improved granulated flame retardant products, wherein the granulated product is characterized as having a friability loss of less than about 8 percent.Type: GrantFiled: March 16, 1995Date of Patent: January 14, 1997Assignee: Albemarle CorporationInventors: Scott A. Bottelberghe, Dustin H. Thomas, Terry M. Shurtleff, Roland G. Poertner
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Patent number: 4593129Abstract: A process for making an alkali metal alkoxide (e.g. sodium alkoxide) of a halogen-substituted alcohol (e.g. fluorine-substituted alcohols) by dispersing an alkali metal (e.g. sodium) in a cycloalkane (e.g. cyclohexane) containing a phenol (e.g. o-allylphenol) and adding the resultant dispersion to an ether (e.g. THF) solution of a halogen-substituted alcohol. The resultant alkali metal haloalkoxide solution contains phenoxides and can be reacted with a phosphonitrilic chloride polymer to introduce haloalkoxide and phenoxide substituents.Type: GrantFiled: April 18, 1984Date of Patent: June 3, 1986Assignee: Ethyl CorporationInventors: R. Woodrow Wilson, Jr., Dustin H. Thomas