Patents by Inventor Lakshmi Krishnamurthy

Lakshmi Krishnamurthy 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).

  • Publication number: 20150166770
    Abstract: The present invention is directed toward a flame retardant article comprising a polyolefin, an activatable flame retardant and an optional flame retardant activator wherein the flame retardant performance of the flame retardant article is at least about 1% higher on the limiting oxygen index (LOI) scale after activation treatment than before activation treatment as measured by LOI ASTM D2863. The flame retardant article can be made into a building substrate, garment, banner, light reflector and cover.
    Type: Application
    Filed: December 5, 2014
    Publication date: June 18, 2015
    Inventors: LAKSHMI KRISHNAMURTHY, BRIAN D. MATHER, MARK GARY WEINBERG
  • Patent number: 8883893
    Abstract: The present invention relates to a flame retardant plexifilamentary film-fibril strand comprising at least one polyolefin and at least one flame retardant selected from the group consisting of: phosphate esters, phosphonate esters, phosphinate esters, polyphosphazines, nitrogen-containing polyphosphates, hindered amines and mixtures thereof. The present invention also relates to flame retardant sheet made from the flame retardant plexifilamentary film-fibril strands. The sheet can be made into a flame retardant building substrate, garment, banner, light reflector and cover.
    Type: Grant
    Filed: April 17, 2012
    Date of Patent: November 11, 2014
    Assignee: E I du Pont de Nemours and Company
    Inventors: Sabine Gabriel, Lakshmi Krishnamurthy, Mieczyslaw (Michel) Stachnik, Mark Gary Weinberg
  • Patent number: 8852808
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nanoweb consisting essentially of a plurality of nanofibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nanoweb with enhanced properties is also provided.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: October 7, 2014
    Assignee: E I du Ponte de Nemours and Company
    Inventors: Pankaj Arora, Stephane Francois Bazzana, T Joseph Dennes, Eric P Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E Simmonds
  • Publication number: 20130337249
    Abstract: Insulating materials are provided, the insulating materials comprising a nonwoven web comprising a plurality of continuous spunbonded polyester bicomponent fibers. Each of the plurality of bicomponent fibers comprises a) from about 20% by weight to about 80% by weight of poly(ethylene terephthalate) in a core, and b) from about 80% by weight to about 20% by weight of poly(trimethylene terephathalate) in a sheath surrounding the core, wherein the amounts in percent by weight are based on the total weight of each of the plurality of bicomponent fibers. Also provided are electrical apparatuses comprising the insulating materials and a dielectric fluid, as well as a dielectric material comprising the nonwoven web impregnated with at least 10 weight percent of a dielectric fluid.
    Type: Application
    Filed: August 24, 2012
    Publication date: December 19, 2013
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Gyorgyi Fenyvesi, Mark Andrew Harmer, Byoung Sam Kang, Lakshmi Krishnamurthy, Serge Rebouillat, Peter A. Brown, Weiming Qiu
  • Publication number: 20130288136
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nanoweb consisting essentially of a plurality of nanofibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nanoweb with enhanced properties is also provided.
    Type: Application
    Filed: June 26, 2013
    Publication date: October 31, 2013
    Inventors: PANKAJ ARORA, Stephane Francois Bazzana, T. Joseph Dennes, Eric P. Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E. Simmonds
  • Patent number: 8557444
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nanoweb consisting essentially of a plurality of nanofibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nanoweb with enhanced properties is also provided.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: October 15, 2013
    Assignee: E I du Pont de Nemours and Company
    Inventors: Pankaj Arora, Stephane Francois Bazzana, T. Joseph Dennes, Eric P. Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E. Simmonds
  • Publication number: 20130210307
    Abstract: Provided are novel compositions comprising a polyarylene sulfide and at least one tin additive comprising a branched tin(II) carboxylate selected from the group consisting of Sn(O2CR)2, Sn(O2CR)(O2CR?), Sn(O2CR)(O2CR?), and mixtures thereof, where the carboxylate moieties O2CR and O2CR? independently represent branched carboxylate anions and the carboxylate moiety O2CR? represents a linear carboxylate anion. Articles comprising the novel compositions are also provided. In addition, methods to improve the thermal stability of polyarylene sulfides, and methods to improve the thermo-oxidative stability of polyarylene sulfides, through the use of the disclosed branched tin(II) carboxylates are provided. The polyarylene sulfide compositions are useful in various applications which require superior thermal resistance, chemical resistance, and electrical insulating properties.
    Type: Application
    Filed: March 22, 2011
    Publication date: August 15, 2013
    Inventors: Joachim C. Ritter, Joel M. Pollino, Michael T. Pottiger, Yefim Brun, Lakshmi Krishnamurthy, Zheng-Zheng Huang, John C. Howe, Laurie A. Howe, Harry Vaughn Samuelson, Zuohong Yin
  • Publication number: 20130109791
    Abstract: The present invention relates to a flame retardant plexifilamentary film-fibril strand comprising at least one polyolefin and at least one flame retardant selected from the group consisting of: phosphate esters, phosphonate esters, phosphinate esters, polyphosphazines, nitrogen-containing polyphosphates, hindered amines and mixtures thereof. The present invention also relates to flame retardant sheet made from the flame retardant plexifilamentary film-fibril strands. The sheet can be made into a flame retardant building substrate, garment, banner, light reflector and cover.
    Type: Application
    Filed: April 17, 2012
    Publication date: May 2, 2013
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: SABINE GABRIEL, LAKSHMI KRISHNAMURTHY, MIECZYSLAW (MICHEL) STACHNIK, MARK GARY WEINBERG
  • Publication number: 20130012092
    Abstract: A nonwoven web comprising bicomponent fibers. The fibers have continuous phases each of a first polyarylene sulfide (PAS) component and a polymer component. The polymer component may also be a second polyarylene sulfide. The first polyarylene sulfide component contains a tin or a zinc additive or both, and the first polyarylene sulfide component of any given fiber is at least partially exposed to the external surface of that fiber.
    Type: Application
    Filed: March 22, 2011
    Publication date: January 10, 2013
    Inventors: Joel M. Pollino, Lakshmi Krishnamurthy, Joachim C. Ritter, Robert John Duff, Yefim Brun, Zheng-Zheng Huang, Zuohong Yin
  • Publication number: 20130012637
    Abstract: An improved process for forming polyarylene sulfide fibers is provided. The process comprises forming at least one fiber from a polymer melt comprising a polyarylene sulfide and at least one tin additive comprising a branched tin(II) carboxylate. Using such a melt, the fiber forming continuity is improved compared to that of the native polyarylene sulfide melt processed under the same conditions.
    Type: Application
    Filed: March 21, 2011
    Publication date: January 10, 2013
    Inventors: Joachim C. Ritter, Joel M. Pollino, Michael T. Pottiger, Lakshmi Krishnamurthy, John C. Howe, Harry Vaughn Samuelson, Marios Avgousti, Zheng-Zheng Huang, Robert John Duff
  • Publication number: 20130009333
    Abstract: A nonwoven web comprising bicomponent fibers. The fibers have continuous phases each of a first polyarylene sulfide (PAS) component and a polymer component. The polymer component may also be a second polyarylene sulfide. The first polyarylene sulfide component contains a tin or a zinc additive or both, and the first polyarylene sulfide component of any given fiber is at least partially exposed to the external surface of that fiber.
    Type: Application
    Filed: March 17, 2011
    Publication date: January 10, 2013
    Inventors: Lakshmi Krishnamurthy, Zuohong Yin, Joachim C Ritter, Joel M Pollino, Michael T Pottiger, John C Howe, David Matthews Laura, JR., Harry Vaughn Samuelson, Robert John Duff, Zheng-Zheng Huang
  • Publication number: 20130012638
    Abstract: This invention relates to methods for decreasing the complex viscosity of a polyarylene sulfide polymer melt while maintaining the molecular weight of the polyarylene sulfide with time. This invention also relates to polymer melt compositions comprising a polyarylene sulfide, wherein the complex viscosity of the composition is decreased relative to the complex viscosity of the native polyarylene sulfide measured under the same conditions, and the weight average molecular weight of the polyarylene sulfide is maintained. The methods of decreasing the complex viscosity of a polyarylene sulfide-containing polymer melt, and the polymer melt compositions so obtained, are useful in processes to produce fibers, films, nonwovens, and molded parts from polyarylene sulfides.
    Type: Application
    Filed: March 16, 2011
    Publication date: January 10, 2013
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Joachim C. Ritter, Joel M. Pollino, Michael T. Pottiger, Zheng-Zheng Huang, Lakshmi Krishnamurthy, John C. Howe, Marios Avgousti, Zuohong Yin
  • Publication number: 20130011544
    Abstract: A method for stabilizing a polymeric structure against thermo-oxidative degradation is described. A polymeric core structure is provided with a skin layer that contains a skin resin in which the skin resin at least partially envelops a portion of the core structure. The skin structure then provides a barrier that thereby stabilizes the portion of the structure that is enveloped. The skin resin is made from a treated polyarylene sulfide.
    Type: Application
    Filed: March 16, 2011
    Publication date: January 10, 2013
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Joel M. Pollino, Lakshmi Krishnamurthy, Joachim C. Ritter, Robert John Duff, Yefim Brun, Zheng-Zheng Zhuang, Zuohong Yin
  • Publication number: 20120318136
    Abstract: A nonwoven felt for hot gas filtration. The fibers have a polyarylene sulfide (PAS) component that contains a zinc compound. In one embodiment, the PAS comprises at least one zinc(II) salt of an organic carboxylic acid. Also a method for filtering hot gases employing a bag made from a PAS component that contains a zinc or a zinc based additive.
    Type: Application
    Filed: June 15, 2011
    Publication date: December 20, 2012
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: ROBERT JOHN DUFF, Zheng-Zheng Jenny Huang, Lakshmi Krishnamurthy, Rakesh Nambiar, Joel M. Pollino, Joachim C. Ritter, Harry Vaughn Samuelson, Cheng-Hang Chi
  • Publication number: 20120156461
    Abstract: Disclosed are nonwoven webs comprising a plurality of continuous spunbonded bicomponent fibers, wherein each of the plurality of bicomponent fibers comprises 75% by weight of poly(ethylene terephthalate) in a core and 25% by weight of poly(trimethylene terephthalate) in a sheath surrounding the core, wherein the amounts in % by weight are based on the total weight of the bicomponent fiber.
    Type: Application
    Filed: December 17, 2010
    Publication date: June 21, 2012
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventor: Lakshmi Krishnamurthy
  • Publication number: 20110143207
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nanoweb consisting essentially of a plurality of nanofibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nanoweb with enhanced properties is also provided.
    Type: Application
    Filed: October 7, 2010
    Publication date: June 16, 2011
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: PANKAJ ARORA, Stephane Francois Bazzana, T. Joseph Dennes, Eric P. Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E. Simmonds
  • Publication number: 20110143217
    Abstract: This invention provides an electrochemical cell comprising a housing having disposed therewithin, an electrolyte, and a multi-layer article at least partially immersed in the electrolyte; the multi-layer article comprising a first metallic current collector, a first electrode material in electrically conductive contact with the first metallic current collector, a second electrode material in ionically conductive contact with the first electrode material, a porous separator disposed between and contacting the first electrode material and the second electrode material; and, a second metallic current collector in electrically conductive contact with the second electrode material, wherein the porous separator comprises a nanoweb consisting essentially of a plurality of nanofibers of a fully aromatic polyimide. Also provided is a process for preparing the multi-layer article. Further provided is an electrochemical cell wherein the separator is a polyimide nanoweb with enhanced properties.
    Type: Application
    Filed: October 7, 2010
    Publication date: June 16, 2011
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: PANKAJ ARORA, Stephane Francois Bazzana, T. Joseph Dennes, Eric P. Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E. Simmonds
  • Publication number: 20110139331
    Abstract: The invention provides a method for enhancing the properties of polyimide nanowebs, the method comprising subjecting a nanoweb consisting essentially of a plurality of nanofibers of an aromatic polyimide to a temperature at least 50 C.° higher than the imidization temperature thereof for a period of time in the range of 5 seconds to 20 minutes, thereby preparing an enhanced nanoweb. Also provided is a multi-layer article comprising the enhanced nanoweb, and an electrochemical cell comprising the multi-layer article.
    Type: Application
    Filed: October 7, 2010
    Publication date: June 16, 2011
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Pankaj Arora, Stephane Francois Bazzana, T. Joseph Dennes, Eric P. Holowka, Lakshmi Krishnamurthy, Stephen Mazur, Glen E. Simmonds
  • Publication number: 20110144297
    Abstract: The invention provides a process comprising heating a polyamic acid fiber to a temperature in the range of a first temperature and a second temperature for a period of time in the range of 5 seconds to 5 minutes to form a polyimide fiber, wherein the first temperature is the imidization temperature of the polyamic acid and the second temperature is the decomposition temperature of the polyimide
    Type: Application
    Filed: October 7, 2010
    Publication date: June 16, 2011
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: T. Joseph Dennes, Lakshmi Krishnamurthy, Glen E. Simmonds, Simon Frisk