Patents by Inventor Srinivas Siripurapu

Srinivas Siripurapu 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: 20070048527
    Abstract: A laminate contains a first layer and a second layer. The first layer contains a first composition that contains polycarbonate, polycarbonate-polysiloxane copolymer, impact modifier and polyetherimide, wherein the polycarbonate constitutes at least about 50% by weight of the composition and a 3.2 millimeter thick, 7.6 centimeter square sample of the first composition produces a smoke density (Ds) of less than 275 after a 4-minute burn, measured according to ASTM E 662-03. The first composition may contain about 50 wt. % to about 97 wt. % polycarbonate, about 0.5 wt. % to about 25 wt. % polycarbonate-polysiloxane copolymer, about 0.5 wt. % to about 20 wt. % impact modifier, and about 2 wt.% to about 15 wt. % polyetherimide, by weight. An article may contain a sheet or film made from such a composition. A laminate or article may be made to include a first layer or sheet that includes such a composition.
    Type: Application
    Filed: December 22, 2005
    Publication date: March 1, 2007
    Inventors: Naveen Agarwal, Thomas Ebeling, Srinivas Siripurapu
  • Publication number: 20060205848
    Abstract: A flame retardant thermoplastic composition having excellent physical properties comprises about 50 to about 90 wt. % of a polycarbonate resin; from about 5 to about 35 wt. % of an impact modifier; about 0.5 to about 30 wt. % of a polysiloxane-polycarbonate copolymer comprising about 8 to about 30 wt. % polydimethylsiloxane units or the equivalent molar amount of other diorganosiloxane units; and about 0.5 to about 20 wt. % of a phosphorus-containing flame retardant, each based on the total combined weight of the thermoplastic composition, exclusive of any filler. In one embodiment a sample of the thermoplastic composition having a thickness of 2.5 mm (±10%) achieves a UL94 5VA rating. Thinner samples may also achieve this rating. The compositions are useful in forming flame retardant thin-walled articles.
    Type: Application
    Filed: April 19, 2006
    Publication date: September 14, 2006
    Applicant: General Electric Company
    Inventors: Srinivas Siripurapu, Mohammad Basha, A.V. Praveenraj
  • Publication number: 20060074156
    Abstract: A thermoplastic composition contains about 20 to about 90 wt. % of a polycarbonate resin; up to about 35 wt. % of an impact modifier; about 0.5 to about 30 wt. % of a polysiloxane-polycarbonate copolymer; and about 0.5 to about 20 wt. % of a phosphorus-containing flame retardant, each based on the total combined weight of the thermoplastic composition, exclusive of any filler. An article of manufacture having a wall having a thickness of 3 mm or less may be made using the composition, e.g., by molding, extruding, or shaping the above-described composition into an article. Alternatively, an article may be made by ultrasonically welding a first part comprising the foregoing composition a second part.
    Type: Application
    Filed: October 4, 2004
    Publication date: April 6, 2006
    Inventors: Thomas Ebeling, Monica Marugan, Srinivas Siripurapu
  • Publication number: 20060030647
    Abstract: A flame retardant thermoplastic composition having excellent physical properties comprises about 20 to about 90 wt. % of a polycarbonate resin; up to about 35 wt. % of an impact modifier; about 0.5 to about 30 wt. % of a polysiloxane-polycarbonate copolymer comprising about 8 to about 30 wt. % polydimethylsiloxane units or the equivalent molar amount of other diorganosiloxane units; and about 0.5 to about 20 wt. % of a phosphorus-containing flame retardant, each based on the total combined weight of the thermoplastic composition, exclusive of any filler. In one embodiment a sample of the thermoplastic composition having a thickness of 2.5 mm (±10 % ) achieves a UL94 5VA rating Thinner samples may also achieve this rating. The compositions are useful in forming flame retardant thin-walled articles.
    Type: Application
    Filed: August 5, 2004
    Publication date: February 9, 2006
    Inventors: Thomas Ebeling, Monica Marugan, Zhaohui Qu, Srinivas Siripurapu
  • Patent number: 6790870
    Abstract: A method of producing a foamed material comprises contacting a mixture comprising a first thermoplastic polymer and a second thermoplastic polymer with a blowing agent, wherein the first thermoplastic polymer has a higher percent crystallinity that the second thermoplastic polymer; and subjecting the mixture to conditions sufficient to create a thermodynamic instability in the blend foam the mixture, wherein the mixture comprising the first and second thermoplastic polymers has a percent crystallinity lower than the first thermoplastic polymer.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: September 14, 2004
    Assignees: North Carolina State University, The University of North Carolina at Chapel Hill
    Inventors: Joseph M. DeSimone, Saad A. Khan, Joseph R. Royer, Richard J. Spontak, Teri Anne Walker, Yvon J. Gay, Srinivas Siripurapu
  • Publication number: 20020168509
    Abstract: Polymeric materials having a plurality of cells formed therein are described. The polymeric materials include a foamed layer comprising a plurality of uniform microcells, nanocells or combinations thereof in a closed cell network, a transition layer positioned adjacent to the foamed layer, and at least one unfoamed outer layer positioned adjacent to the transition layer. The foamed layer may be present in a volume ranging from about 80 to about 99 percent based on the volume of the polymeric material, the transition layer may present in a volume ranging from about 0 to about 10 percent based on the volume of the polymeric material, and the at least one outer layer may be present in a volume ranging from about 0.01 to about 10 percent based on the volume of the polymeric material. Methods of making such polymeric materials are also described, as are apparatus for providing foamed polymeric materials.
    Type: Application
    Filed: March 27, 2002
    Publication date: November 14, 2002
    Inventors: Joseph M. DeSimone, Srinivas Siripurapu, Saad A. Khan, Richard J. Spontak, Joseph Royer