Patents by Inventor Thirumurti Narayan
Thirumurti Narayan 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: 5491252Abstract: The invention provides a liquid polyisocyanate prepolymer composition which is a result of combining about 50 to 90 percent by weight of an isocyanate blend (a.) having 55 to 75 weight percent 4,4'-MDI, 17 to 27 weight percent 2,4'-MDI, 1 to 10 weight percent 3-ring MDI oligomer, and 1 to 15 weight percent n-ring MDI oligomer (n greater than 3); about 5 to 30 weight percent of a polyhydroxy containing polyol (b.) having a molecular weight of from 700 to about 6,000, and about 5 to 15 weight percent of a toluene diisocyanate (c.). The resulting isocyanate prepolymer composition has a free NCO content of from about 20 to 40 weight percent and particularly desirable flow characteristics. The invention further provides a method of making an isocyanate prepolymer composition, a process of making a polyurethane foam utilizing the isocyanate prepolymer composition of the invention, and polyurethane foams produced by the disclosed process.Type: GrantFiled: April 10, 1995Date of Patent: February 13, 1996Assignee: BASF CorporationInventors: Thirumurti Narayan, David J. Lovell, Carlos H. Lopez
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Patent number: 5459221Abstract: The invention provides a liquid polyisocyanate prepolymer composition which is a result of combining about 50 to 90 percent by weight of an isocyanate blend (a.) having 55 to 75 weight percent 4,4'-MDI, 17 to 27 weight percent 2,4'-MDI, 1 to 10 weight percent 3-ring MDI oligomer, and 1 to 15 weight percent n-ring MDI oligomer (n greater than 3); about 5 to 30 weight percent of a polyhydroxy containing polyol (b.) having a molecular weight of from 700 to about 6,000, and about 5 to 15 weight percent of a toluene diisocyanate (c.). The resulting isocyanate prepolymer composition has a free NCO content of from about 20 to 40 weight percent and particularly desirable flow characteristics. The invention further provides a method of making an isocyanate prepolymer composition, a process of making a polyurethane foam utilizing the isocyanate prepolymer composition of the invention, and polyurethane foams produced by the disclosed process.Type: GrantFiled: April 10, 1995Date of Patent: October 17, 1995Assignee: BASF CorporationInventors: Thirumurti Narayan, David J. Lovell, Carlos H. Lopez
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Patent number: 5436277Abstract: The invention provides a liquid polyisocyanate prepolymer composition which is a result of combining about 50 to 90 percent by weight of an isocyanate blend (a.) having 55 to 75 weight percent 4,4'-MDI, 17 to 27 weight percent 2,4'-MDI, 1 to 10 weight percent 3-ring MDI oligomer, and 1 to 15 weight percent n-ring MDI oligomer (n greater than 3); about 5 to 30 weight percent of a polyhydroxy containing polyol (b.) having a molecular weight of from 700 to about 6,000, and about 5 to 15 weight percent of a toluene diisocyanate (c.). The resulting isocyanate prepolymer composition has a free NCO content of from about 20 to 40 weight percent and particularly desirable flow characteristics. The invention further provides a method of making an isocyanate prepolymer composition, a process of making a polyurethane foam utilizing the isocyanate prepolymer composition of the invention, and polyurethane foams produced by the disclosed process.Type: GrantFiled: July 28, 1994Date of Patent: July 25, 1995Assignee: BASF CorporationInventors: Thirumurti Narayan, David J. Lovell, Carlos H. Lopez
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Patent number: 5382646Abstract: Poly(urethane-urea) reaction injection molded compositions having improved processing and lower water absorption are prepared by reacting an isocyanate-terminated prepolymer prepared by reacting 4,4'-MDI or modified 4,4'-MDI and a polyoxypropylene glycol having a molecular weight of from 400 to 2500 with a polyether polyol and a hindered amine or glycol chain extender, in the presence of a urethane-reaction promoting catalyst, optionally including a hydroxyl terminated chain extender and internal mold release agent.Type: GrantFiled: August 2, 1994Date of Patent: January 17, 1995Assignee: BASF CorporationInventors: Thirumurti Narayan, Samuel E. Johnson, Michael A. Dimitroff, Dietrich Schlotterbeck
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Patent number: 5338820Abstract: The invention relates to water blown integral skin polyurethane foams made with a particular isocyanate quasi-prepolymer and resin side ingredients to yield a foam having good overall mechanical roperties. The isocyanate quasi-prepolymer component of the present invention comprises from 0.5 weight percent to 30.0 weight percent or less uretonimine-carbodiimide-modified diphenylmethane diisocyanate, from 50 weight percent to 80 weight percent 4,4'-diphenylmethane diisocyanate and reacted with from 15 weight percent to 40 weight percent of a polyether polyol containing predominately secondary hydroxy groups and having an average molecular weight from about 2,000 to 10,000, an average functionality from 1.5 to about 3.2, and a hydroxyl number from about 20 to 60. The resin side component comprises a high molecular weight polyether polyol with an average functionality from 1.5 to about 3.2, water as a blow agent, and optionally an mono- or di-functional alcohol composition having from 8 to about 30 carbon atoms.Type: GrantFiled: February 4, 1994Date of Patent: August 16, 1994Assignee: BASF CorporationInventors: Richard P. Harrison, Michael Scarpati, Thirumurti Narayan, Blair J. Zagata
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Patent number: 5338819Abstract: Solid isocyanate-terminated prepolymer powders useful in preparation of films, coatings, and one-component adhesives are prepared by reacting a low molecular weight di- or polyisocyanate with a glycol mixture in a solvent in which the isocyanate is soluble but the reaction product is not.Type: GrantFiled: November 29, 1991Date of Patent: August 16, 1994Assignee: BASF CorporationInventors: Thirumurti Narayan, Anthony W. Tantillo, John R. Stoll
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Patent number: 5288766Abstract: Stable urea group-containing dispersions are obtained in situ by reacting carbon dioxide with an amine in the presence of a continuous phase carrier. These amine/carbon dioxide condensation adducts dispersed in the carrier are employed in the formation of polyurethane foams, polyurethane elastomers and coatings, and polyurethane microcellular foams.Type: GrantFiled: February 28, 1992Date of Patent: February 22, 1994Assignee: BASF CorporationInventors: Thirumurti Narayan, Michael G. Kinnaird
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Patent number: 5284880Abstract: The invention relates to water blown integral skin polyurethane foams made with a particular isocyanate quasi-prepolymer and resin side ingredients to yield a foam having good overall mechanical properties. The isocyanate quasi-prepolymer component of the present invention comprises from 0.5 weight percent to 30.0 weight percent or less uretonimine-carbodiimide-modified diphenylmethane diisocyanate, from 50 weight percent to 80 weight percent 4,4'-diphenylmethane diisocyanate and reacted with from 15 weight percent to 40 weight percent of a polyether polyol containing predominately secondary hydroxyl groups and having an average molecular weight from about 2,000 to 10,000, an average functionality from 1.5 to about 3.2, and a hydroxyl number from about 20 to 60, and optionally with a low molecular weight diol in an amount of from 1.0 weight percent to 10 weight percent, the weight percentages based on the weight of the quasi-prepolymer reactants.Type: GrantFiled: September 20, 1993Date of Patent: February 8, 1994Assignee: BASF CorporationInventors: Richard P. Harrison, Michael Scarpati, Thirumurti Narayan, Blair J. Zagata
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Patent number: 5283311Abstract: Fatty prepolymers and fatty modidified organic polyisocyantes are provided as internal mold release agents useful in Reaction Injection Molded (RIM) parts. A terminal fatty chain-containing molecule having a primary or secondary hydroxyl group, a primary or secondary amine group, an epoxide group, or an isocyanate group is reacted with an organic aromatic polyisocyanate to yield a fatty prepolymer having a urethane linkage, a urea linkage, or an oxazolidinone linkage; or to yield a fatty modified polyisocyanate having an allophanate linkage, a biuret linkage, or a carbodiimide-uretonimine linkage. The terminal chain on the molecule contains at least 8 branched or unbranched, saturated or unsaturated, hydrogen substituted aliphatic carbon atoms in succession or at least 5 branched or unbranched, aliphatic or cycloaliphatic perfluorinated atoms in succession.Type: GrantFiled: December 30, 1992Date of Patent: February 1, 1994Assignee: BASF CorporationInventors: Thirumurti Narayan, Anthony Tantillo, William G. Conger
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Patent number: 5264620Abstract: The present invention is a prepolymer or quasi-prepolymer formed from the reaction of a given amount of a diphenyl methane diisocyanate having at least 5 percent of the 2,4'-isomer and polytetramethylene ether glycols having a molecular weight between 162 and 3000. The glycol which may be combined with other polyether or polyester glycols. The resulting NCO-terminated prepolymer or quasi polymer is a liquid which is stable at temperature of 15.degree. C. for at least 24 hours.Type: GrantFiled: March 8, 1991Date of Patent: November 23, 1993Assignee: BASF CorporationInventor: Thirumurti Narayan
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Patent number: 5258417Abstract: The present invention deals with a polymethylene polyphenylisocyanate blend having a viscosity range of from 15 to 37 cps at 25.degree. C. Specifically, the blend is prepared by mixing a polymethylene polyphenylisocyanate with monomeric diphenylmethane diisocyanate. The unique characteristics of this product are that it displays good storage stability under ambient conditions and has a low viscosity. It is useful in the production of polyurethane foams and adhesives.Type: GrantFiled: December 28, 1992Date of Patent: November 2, 1993Assignee: BASF CorporationInventor: Thirumurti Narayan
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Patent number: 5236960Abstract: The invention relates to water blown integral skin polyurethane foams made with a particular isocyanate quasi-prepolymer and resin side ingredients to yield a foam having good overall mechanical properties. The isocyanate quasi-prepolymer component of the present invention comprises from 0.5 weight percent to 30.0 weight percent or less uretonimine-carbodiimide-modified diphenylmethane diisocyanate, from 50 weight percent to 80 weight percent 4,4'-diphenylmethane diisocyanate and reacted with from 15 weight percent to 40 weight percent of a polyether polyol containing predominately secondary hydroxyl groups and having an average molecular weight from about 2,000 to 10,000, an average functionality from 1.5 to about 3.2, and a hydroxyl number from about 20 to 60, and optionally with a low molecular weight diol in an amount of from 1.0 weight percent to 10 weight percent, the weight percentages based on the weight of the quasi-prepolymer reactants.Type: GrantFiled: January 19, 1993Date of Patent: August 17, 1993Assignee: BASF CorporationInventors: Richard P. Harrison, Michael Scarpati, Thirumurti Narayan, Blair J. Zagata
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Patent number: 5216035Abstract: The invention relates to water blown integral skin polyurethane foams made with a particular isocyanate quasi-prepolymer and resin side ingredients to yield a foam having good overall mechanical properties. The isocyanate quasi-prepolymer component of the present invention comprises from 0.5 weight percent to 30.0 weight percent or less uretonimine-carbodiimide-modified diphenylmethane diisocyanate, from 50 weight percent to 80 weight percent 4,4'-diphenylmethane diisocyanate and reacted with from 15 weight percent to 40 weight percent of a polyether polyol containing predominately secondary hydroxyl groups and having an average molecular weight from about 2,000 to 10,000, an average functionality from 1.5 to about 3.2, and a hydroxyl number from about 20 to 60, and optionally with a low molecular weight diol in an amount of from 1.0 weight percent to 10 weight percent, the weight percentages based on the weight of the quasi-prepolymer reactants.Type: GrantFiled: June 22, 1992Date of Patent: June 1, 1993Assignee: BASF CorporationInventors: Richard P. Harrison, Michael Scarpati, Thirumurti Narayan, Blair J. Zagata
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Patent number: 4803229Abstract: Molded flexible polyurethane foam is prepared by reacting a polyol with a urea-biuret modified polyisocyanate mixture which is composed of toluene diisocyanate and polymeric diphenylmethane diisocyanate.Type: GrantFiled: January 6, 1986Date of Patent: February 7, 1989Assignee: BASF CorporationInventors: Thirumurti Narayan, Edward R. Pray, John R. Stoll
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Patent number: 4791148Abstract: Polyurethane/polyisocyanurate rigid foams having low thermal conductivity are prepared from isocyanate-terminated quasi-prepolymers prepared from polyester polyols derived from phthalic anhydride or from the transesterification of polyethylene terephthalate scrap.Type: GrantFiled: February 12, 1987Date of Patent: December 13, 1988Assignee: BASF CorporationInventors: Robert E. Riley, Thirumurti Narayan
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Patent number: 4757095Abstract: Lactones and lactams are utilized in the preparation of urethane modified prepolymers based on diphenylmethane diisocyanate, uretonimine-modified diphenylmethane diisocyanate. The prepolymers are then employed to prepare microcellular foams suitable for shoe soles and cast polyurethane products.Type: GrantFiled: June 9, 1987Date of Patent: July 12, 1988Assignee: BASF CorporationInventors: Robert J. Galan, Thirumurti Narayan
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Patent number: 4743627Abstract: A method for producing liquid isocyanurate modified Polymeric MDI composition containing a high two-ring MDI content, and foams made therefrom is described. The method comprises trimerizing a polymeric MDI in the presence of catalytically effective amount of a trimerization catalyst to form an isocyanurate containing polyisocyanate having a viscosity of about 100,000 mPas. The trimerization catalyst is thereafter deactivated and the isocyanurate-modified polyisocyanate is blended with a methylene bis(phenylisocyanate) (MDI) to form a final product having a two-ring content of about 60 percent of the total ring content and a viscosity comparable to polymeric MDI. Foams produced using this liquid isocyanurate modified polymeric MDI are of a substantially lighter color than those produced from standard polymeric MDI.Type: GrantFiled: September 14, 1987Date of Patent: May 10, 1988Assignee: BASF CorporationInventors: Thirumurti Narayan, Peter T. Kan
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Patent number: 4743626Abstract: A process for the preparation of liquid polymethylene polyphenylene polyisocyanate blends containing carbodiimide-uretonimine isocyanate linkages, containing a high two-ring methylene bis(phenylisocyanate) content, and light colored polyurethane foams made therefrom. The process is comprised of reacting polymethylene polyphenylene polyisocyanate with a catalytically effective amount of a carbodiimide-uretonimine promoting compound at a temperature sufficient to promote the formation of carbodiimide-uretonimine linkages and an isocyanate content of about 25 percent and the desired viscosity is reached, and then reacting that product to deactivate the carbodiimide-uretonimine catalyst, and finally blending two ring methylene bis(phenylisocyanate) with the product to produce a mixture having a two ring isocyanate content of about 60 percent of the total ring content and a viscosity comparable to standard polymeric MDI.Type: GrantFiled: September 14, 1987Date of Patent: May 10, 1988Assignee: BASF CorporationInventor: Thirumurti Narayan
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Patent number: 4738991Abstract: Organic polyisocyanates characterized by allophanate linkages are prepared by reacting an organic polyisocyanate with a mono- or polyhydric compound in the presence of an organo metal catalyst. The catalyst is then deactivated using a compound such as an inorganic acid, organic acid, organic chloroformate or an organic acid chloride. The isocyanates are useful in preparing polyurethane foams.Type: GrantFiled: January 23, 1987Date of Patent: April 19, 1988Assignee: BASF CorporationInventor: Thirumurti Narayan
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Patent number: 4717774Abstract: The invention relates to an improved process for the preparation of toluene diamine from dinitrotoluene involving hydrogenation of dinitrotoluene with hydrogen gas at elevated temperatures and super atmospheric pressure in the presence of a supported nickel catalyst and carbon monoxide ranging from 0.001 to 0.1 volume percent. The rate of hydrogenation, product quality and yield are improved when hydrogen spiked with small amounts of carbon monoxide was used.Type: GrantFiled: December 20, 1985Date of Patent: January 5, 1988Assignee: BASF CorporationInventors: Thirumurti Narayan, Peter T. Kan