Patents by Inventor Munirpallam Subramanian

Munirpallam Subramanian 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).

  • Patent number: 6224781
    Abstract: A process is disclosed for producing compositions including (a) a compound selected from the group consisting of CHF2CF3, CHF2CHF2, CH2FCF3, CH3CF3, CH3CHF2, CH2FCF2CHF2 and CHF2CF2CF2CHF2 and (b) at least one saturated halogenated hydrocarbon and/or ether having the formula: CnH2n+2−a−bClaFbOc wherein n is an integer from 1 to 4, a is an integer from 0 to 2n+1, b is an integer from 1 to 2n+2−a, and c is 0 or 1, provided that when c is 1 then n is an integer from 2 to 4, and provided that component (b) does not include the selected component (a) compound, wherein the molar ratio of component (b) to component (a) is between about 1:99 and a molar ratio of HF to component (a) in an azeotrope or azeotrope-like composition of component (a) with HF.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: May 1, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Barry A. Mahler, V. N. Mallikarjuna Rao, Allen Capron Sievert, Munirpallam A. Subramanian, Edwin James Warwas
  • Patent number: 6166273
    Abstract: A process is provided for increasing the fluorine content of benzene or pyridine rings which are optionally substituted with from 1 to 3 inert substituents. The process involves (a) contacting the ring with a metal fluoride composition comprising cupric fluoride (CuF.sub.2) at a temperature above 250.degree. C. sufficient to transfer F from cupric fluoride to the optionally substituted ring, thereby chemically reducing the metal fluoride composition; (b) oxidizing the reduced metal fluoride composition from (a) in the presence of HF to regenerate a metal fluoride composition comprising cupric fluoride; and (c) employing regenerated metal fluoride composition of (b) in (a).
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: December 26, 2000
    Assignee: E.I. du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 6127585
    Abstract: Processes are disclosed for decreasing the chlorine to carbon ratio for halogenated hydrocarbons containing chlorine and from 1 to 6 carbon atoms, in the presence of a multiphase catalyst. The processes each involve (1) preparing a single phase solid catalyst precursor which has a structure that collapses at a temperature of about 400.degree. C. or less and has the formula (NH.sub.3).sub.6 Ru.sub.l-r-s Co.sub.r Cr.sub.s MF.sub.6, where r+s is in the range of 0.00 to 0.99, and M is at least one trivalent metal selected from the group consisting of Al, Cr, Fe, V, Sc and Ga; and (2) producing the multiphase catalyst by heating the single phase solid catalyst precursor to about 400.degree. C. or less in an non-oxidizing atomsphere to produce a multiphase composition wherein a phase containing ruthenium is homogeneously dispersed with a phase containing metal fluoride.Also disclosed are single phase fluoride compositions having the formula (NH.sub.3).sub.6 Ru.sub.l-r-s Co.sub.r Cr.sub.s MF.sub.
    Type: Grant
    Filed: May 27, 1998
    Date of Patent: October 3, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Timothy C. Duzick, Velliyur Nott Mallikarjuna Rao, Munirpallam A. Subramanian
  • Patent number: 6107267
    Abstract: A process is disclosed for recovering HF from a product mixture including HF and CF.sub.3 CF.sub.2 CHF.sub.2. The process involves (1) distilling the product mixture to remove all products which have a lower boiling point than the lowest boiling azeotrope containing HF and CF.sub.3 CF.sub.2 CHF.sub.2 ; and (2) distilling the azeotrope to recover HF as an azeotropic composition containing HF and CF.sub.3 CF.sub.2 CHF.sub.2. Also disclosed are compositions of hydrogen fluoride in combination with an effective amount of CF.sub.3 CF.sub.2 CHF.sub.2 to form an azeotrope or azeotrope-like composition with hydrogen fluoride, (e.g., compositions containing from about 57.1 to 67.2 mole percent CF.sub.3 CF.sub.2 CHF.sub.2).A process for producing certain compositions comprising(a) CF.sub.3 CF.sub.2 CHF.sub.2 and (b) at least one saturated halogenated hydrocarbon and/or ether having the formula:C.sub.n H.sub.2n+2-a-b Cl.sub.a F.sub.b O.sub.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: August 22, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Allen Capron Sievert, Munirpallam A. Subramanian
  • Patent number: 6096932
    Abstract: A process is disclosed for increasing the fluorine content of an olefinic compound of the formula C.sub.n H.sub.m F.sub.2n-m, where n is an integer from 2 to 6 and m is an integer from 1 to 2n. The process involves (a) contacting the olefinic compound with a metal fluoride composition of the formula (AgF)(MF.sub.2).sub.x where M is selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn and mixtures thereof and x is a number from 0 to 1, at a temperature above 200.degree. C. sufficient to transfer F from the metal fluoride composition to the olefinic compound, thereby producing a chemically reduced metal fluoride composition comprising metallic silver; (b) oxidizing the reduced metal fluoride composition from (a) in the presence of HF to regenerate the metal fluoride composition of the formula (AgF)(MF.sub.2).sub.x ; and (c) recycling regenerated metal fluoride composition of (b) to (a). Also disclosed are a novel composition of the formula Ag.sub.10 F.sub.8 C.sub.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: August 1, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 6087543
    Abstract: A process is disclosed for producing fluorinated benzene. The process involves (a) contacting chlorobenzene starting material with a metal fluoride composition of the formula (AgF)(MF.sub.2).sub.x (where M is Mn, Fe, Co, Ni, Cu, Zn or a mixture thereof and x is a number between 0 and 1) at a temperature above 175.degree. C. sufficient to remove the chlorine substituent from the starting material and to transfer F from the metal fluoride composition to the starting material (thereby producing a reduced metal fluoride composition comprising a silver component of the formula AgF.sub.1-y where y is a number from 0.01 to 1); (b) oxidizing the reduced metal fluoride composition from (a) in the presence of HF to regenerate the metal fluoride mixture composition of the formula (AgF)(MF.sub.2).sub.x ; and (c) recycling regenerated metal fluoride composition of (b) to (a).
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: July 11, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 6031141
    Abstract: This invention provides a process for the manufacture of a fluoroolefin of the formula (R.sup.1).sub.2 C.dbd.C(R.sup.1).sub.2 wherein each R.sup.1 is independently selected from the group consisting of --H, --F, --CF.sub.3, --CHF.sub.2, --CH.sub.2 F, --C.sub.2 F.sub.5, --C.sub.2 HF.sub.4 and --C.sub.2 H.sub.2 F.sub.3, provided that at least one R.sup.1 is not --H. The process comprises contacting a hydrofluorocarbon of the formula (R.sup.1).sub.2 CHCF(R.sup.1).sub.2 with a catalyst comprising cubic chromium trifluoride, i.e., a chromium trifluoride having an X-ray diffraction powder pattern shown in Table I, at a temperature of from about 200.degree. C. to about 500.degree. C.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: February 29, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Rao V.N. Mallikarjuna, Munirpallam A. Subramanian
  • Patent number: 6028026
    Abstract: This invention provides a crystalline chromium fluoride having a cubic crystal structure (i.e., chromium trifluoride having an X-ray diffraction powder pattern as shown in Table I); and a catalytic composition comprising cubic chromium trifluoride. This invention also provides a process for changing the fluorine content of halogenated hydrocarbons containing from one to six carbon atoms, in the presence of a chromium-containing catalyst. The process is characterized by the chromium-containing catalyst comprising cubic chromium trifluoride.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: February 22, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Munirpallam A. Subramanian
  • Patent number: 5880315
    Abstract: A process for the manufacture of vinyl fluoride (i.e., CH.sub.2 .dbd.CHF, VF or 1141) from 1,1-difluoroethane (i.e., CH.sub.3 CHF.sub.2, F152a or HFC-152a) is disclosed which involves contacting the 1,1-difluoroethane at an elevated temperature (200.degree. C.-400.degree. C.) with a multiphase catalyst composition consisting essentially of (a) fluorides of at least one divalent metal selected from magnesium and zinc, and (b) fluorides of trivalent aluminum, in which phases of the divalent fluorides are homogeneously dispersed with phases of the trivalent fluorides.
    Type: Grant
    Filed: November 4, 1997
    Date of Patent: March 9, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: V.N. Mallikarjuna Rao, Munirpallam A. Subramanian
  • Patent number: 5847242
    Abstract: A process is disclosed for changing the fluorine content of halogenated hydrocarbons containing from 1 to 6 carbon atoms, in the presence of a multiphase catalyst, which is characterized by preparing certain single phase solid catalyst precursors containing two metal components (e.g., a divalent component of Mn, Co, Zn, Mg and/or Cd and a trivalent component of Al, Ga, Cr and/or V) which have structures that collapse at about 600.degree. C. or less; and producing said catalyst by heating the precursor to produce a multiphase composition wherein a phase containing one of the metal components is homogeneously dispersed with a phase containing the other metal component, and at least when the precursor contains no fluoride, contacting said multiphase composition with a vaporizable fluorine-containing fluorination compound at a temperature of from about 200.degree. C. to 450.degree. C. Also disclosed are single phase fluoride compositions having the formula MM'F.sub.5 (H.sub.2 O).sub.
    Type: Grant
    Filed: November 21, 1996
    Date of Patent: December 8, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Velliyur Nott Mallikarjuna Rao, Munirpallam A. Subramanian
  • Patent number: 5559069
    Abstract: A process is disclosed for changing the fluorine content of halogenated hydrocarbons containing from 1 to 6 carbon atoms, in the presence of a multiphase catalyst, which is characterized by preparing certain single phase solid catalyst precursors containing two metal components (e.g., a divalent component of Mn, Co, Zn, Mg and/or Cd and a trivalent component of Al, Ga, Cr and/or V) which have structures that collapse at about 600.degree. C. or less; and producing said catalyst by heating the precursor to produce a multiphase composition wherein a phase containing one of the metal components is homogeneously dispersed with a phase containing the other metal component, and at least when the precursor contains no fluoride, contacting said multiphase composition with a vaporizable fluorine-containing fluorination compound at a temperature of from about 200.degree. C. to 450.degree. C. Also disclosed are single phase fluoride compositions having the formula MM'F.sub.5 (H.sub.2 O).sub.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: September 24, 1996
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Munirpallam A. Subramanian
  • Patent number: 5482917
    Abstract: A superconducting composition having the nominal formula TlM.sub.2 CuO.sub.5-x F.sub.x wherein M is Ba and x is from about 0.10 to about 0.65, or M is Sr and x is from about 0.35 to about 0.75 is disclosed.
    Type: Grant
    Filed: September 21, 1993
    Date of Patent: January 9, 1996
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5264414
    Abstract: Compositions having the formula Tl.sub.1-x Bi.sub.x Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.9 wherein x is from about 3/20 to about 11/20 are superconducting with transition temperatures above 110 K. Processes for making and using the compositions of the invention are provided.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: November 23, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5219833
    Abstract: Compositions containing a crystalline phase of the formula Tl.sub.2 Ba.sub.2 CuO.sub.6+x wherein x is from 0 to 0.5. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: June 15, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jagannatha Gopalakrishnan, Munirpallam A. Subramanian
  • Patent number: 5126316
    Abstract: Compositions having the nominal formula Bi.sub.2 Sr.sub.3-x Y.sub.x Cu.sub.2 O.sub.8+y wherein x is from about 0.05 to about 0.45 and y is from about 0 to about 1 are superconducting.
    Type: Grant
    Filed: August 24, 1988
    Date of Patent: June 30, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Arthur W. Sleight, Munirpallam A. Subramanian
  • Patent number: 5070070
    Abstract: Binary memory storage devices and cryotrons utilizing superconducting crystals exhibiting an onset of superconductivity and a relatively weak flux exclusion at a temperature T1 and the onset of relatively strong flux exclusion at T2, where T1>T2>77K, are controlled by dc magnetic fields. The preferred superconducting crystals have the formula Bi.sub.2 Sr.sub.3-z Ca.sub.z Cu.sub.2 O.sub.8+w wherein z is from about 0.1 to about 0.9 and w is greater than zero but less than about 1.
    Type: Grant
    Filed: March 9, 1988
    Date of Patent: December 3, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Thomas R. Askew, Richard B. Flippen, Munirpallam A. Subramanian
  • Patent number: 5036043
    Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition essentially of mixing M.sub.2 O.sub.3, BaO.sub.2 and CuO in an atomic ratio of M:Ba:Cu of about 1:2:3 to obtain a powder mixture; heating the resulting mixture in an oxygen-containing atmosphere at a temperature from about 850.degree. C. to about 925.degree. C. for a time sufficient to form MBa.sub.2 Cu.sub.3 O.sub.y, where y is from about 6.0 to about 6.4; and maintaining the MBa.sub.2 Cu.sub.3 O.sub.y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: July 30, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5017554
    Abstract: Compositions having the nominal formulaTl.sub.e Pb.sub.a Ca.sub.b Sr.sub.c Cu.sub.d O.sub.xwherein a is from about 1/10 to 3/2,b is from about 1 to 4,c is from about 1 to 3d is from about 1 to 5e is from about 3/10 to 1x=(a+b+c+d+e+y) where y is from about 1/2 to 3,are superconducting. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: May 21, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 4983573
    Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tn, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition temperature of about 90.degree. K.; said process consisting essentially of preparing a precursor solution, drying the solution to obtain a solid material, and heating and cooling the solid material under specified conditions to obtain the desired product. In another embodiment, a shaped superconducting MBa.sub.2 Cu.sub.3 O.sub.x article is prepared by impregnating an article of cellulose material with the precursor solution, drying the impregnated article, and heating and cooling the impregnated article under prescribed conditions to obtain the desired product.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: January 8, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bolt, Munirpallam A. Subramanian
  • Patent number: 4929594
    Abstract: Compositions containing a crystalline phase of the formula Tl.sub.2 Ba.sub.2 CuO.sub.6+x wherein x is from 0 to 0.5. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: March 14, 1988
    Date of Patent: May 29, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jagannatha Gopalakrishnan, Munirpallam A. Subramanian