Patents by Inventor Raj B. Durairaj

Raj B. Durairaj 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: 6531637
    Abstract: A process for the preparation of resorcinol using the meta-phenylenediamine hydrolysis reaction is provided. A reactor vessel made of a suitable material such as zirconium or a zirconium alloy is used, thus resisting corrosion and formation of resinous materials.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: March 11, 2003
    Assignee: Indspec Chemical Corporation
    Inventors: Raj B. Durairaj, Gary A. Jesionowski
  • Patent number: 6472457
    Abstract: Methods for preparing formaldehyde-free resorcinol resins are disclosed. The methods generally comprise reacting resorcinol first with dicyclopentadiene and then reacting that mixture with an olefinic compound. The resins produced by this method are also disclosed, as are rubber compositions utilizing the present resins. The resins are characterized as having a free resorcinol content of about 1 wt. % or less, and yielding a suitable softening point when used in rubber applications.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: October 29, 2002
    Assignee: Indspec Chemical Corporation
    Inventors: Raj B. Durairaj, Alex Peterson, Jr.
  • Patent number: 6350921
    Abstract: Improved methods for the simultaneous production of dihydroxybenzene and dicarbinol from diisopropylbenzene are provided. These methods provide for continuous and simultaneous production of diisopropylbenzene dihydroperoxide (DHP) and diisopropylbenzene hydroxyhydroperoxide (HHP) using Karr Column extractors operated in series. A very high purity DHP-containing solution, the precursor to the dihydroxybenzene, can be produced according to the reported methods. A safe and efficient method for producing dicarbinol from HHP is also disclosed.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: February 26, 2002
    Assignee: Indspec Chemical Corporation
    Inventors: Raj B. Durairaj, Vaughn J. Romell, Michael N. Tackie, Thomas K. Volek
  • Patent number: 6303732
    Abstract: Novel diol blends are disclosed. The blends are comprised of an aromatic diol portion derived from dihydric phenol and an aliphatic diol portion in a ratio of aromatic to aliphatic of 5:95 to 95:5. The aromatic portion is the reaction product of a dihydric phenol and one or more alkylene carbonates using a stoichiometric excess of carbonate. Methods for preparing these diol blends are also disclosed, as are methods for using these compounds in the preparation of cast elastomers. Cast elastomers prepared from these blends are also disclosed; the elastomers have physical and mechanical properties that make them appropriate for use in many demanding applications.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: October 16, 2001
    Assignee: Indspec Chemical Corporation
    Inventor: Raj B. Durairaj
  • Patent number: 5945500
    Abstract: Methods for preparing low free resorcinol resins are disclosed. These methods generally comprise reacting a resin with an aromatic olefinic compound; suitable resins include one or more resins selected from the group consisting of a dihydric phenol, a polyhydric phenol, a dihydric phenolic novolak resin and a polyhydric phenolic novolak resin; the addition product of at least one of these resins and at least one compound selected from the group consisting of a monooxirane compound and a polyoxirane compound; and a phenol or alkyl or aralkyl substituted mono- or dihydric phenol modified form of these resins. The resins produced by this method are also disclosed, as are rubber compositions utilizing the resin produced by this method.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: August 31, 1999
    Assignee: Indspec Chemical Corp.
    Inventors: Raj B. Durairaj, Alex Peterson, Jr.
  • Patent number: 5936056
    Abstract: Methods for preparing low free resorcinol resins are disclosed. These methods generally comprise reacting a resin with an aromatic olefinic compound; suitable resins include one or more resins selected from the group consisting of a dihydric phenol, a polyhydric phenol, a dihydric phenolic novolak resin and a polyhydric phenolic novolak resin; the addition product of at least one of these resins and at least one compound selected from the group consisting of a monooxirane compound and a polyoxirane compound; and a phenol or alkyl or aralkyl substituted mono- or dihydric phenol modified form of these resins. The resins produced by this method are also disclosed, as are rubber compositions utilizing the resin produced by this method.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: August 10, 1999
    Assignee: Indspec Chemical Corporation
    Inventors: Raj B. Durairaj, Alex Peterson, Jr.
  • Patent number: 5300618
    Abstract: A curable resorcinol-based epoxy resin is disclosed having the general structural formula (I) ##STR1## wherein at least one of R.sub.1, R.sub.2, or R.sub.3 is selected from the group consisting of (a) the general structural formula (II) ##STR2## wherein R.sub.4 is selected from the group consisting of hydrogen and an alkyl group having 1 to about 4 carbon atoms, and (b) an allyl group.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: April 5, 1994
    Assignee: Indspec Chemical Corporation
    Inventor: Raj B. Durairaj