Patents by Inventor Vasanth R. Kamath

Vasanth R. Kamath 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: 5096947
    Abstract: A composition comprises a thermoplastic or polymeric resin; an organic peroxide; and an organic sulfide antioxidant represented by Formula I, II or III: ##STR1## wherein m, n, r, R.sup.1, R.sup.2, R.sup.3, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are as set forth in the Summary of the Invention.
    Type: Grant
    Filed: May 6, 1991
    Date of Patent: March 17, 1992
    Assignee: Atochem North America, Inc.
    Inventors: Joseph M. Bohen, Edward P. Hibbard, Vasanth R. Kamath, James L. Reilly
  • Patent number: 4975494
    Abstract: Acrylic coating resins with attached light stabilizer functional groups are provided.The polymer bound light stabilizer coating resins are prepared by reacting light stabilizer hydrazides, LS--C(.dbd.O)--NR.sup.3 --NH.sub.2, with an acrylic prepolymer containing at least two different types of reactive functional groups, one of which is a hydroxyalkyl ester group and the other is carboxyl, anhydride, epoxy or isocyanate. LS is a light stabilizer moiety, and R.sup.3 is hydrogen, primary alkyl of 1 to 8 carbons, secondary alkyl of 3 to 8 carbons, aralkyl of 7 to 12 carbons or cycloalkyl of 5 to 12 carbons. The reaction may be carried out in an inert solvent or in the bulk state.The acrylic resins so produced with chemically bound light stabilizer groups are particularly useful in the stabilization of coatings. Enamel or lacquer coatings containing the polymer bound light stabilizer resins exhibit outstanding weatherability and durability.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: December 4, 1990
    Assignee: Atochem of North America, Inc.
    Inventors: Vasanth R. Kamath, James D. Sargent
  • Patent number: 4927891
    Abstract: Acrylic coating resins with attached light stabilizer functional groups are provided.The polymer bound light stabilizer coating resins are prepared by reacting light stabilizer hydrazides, LS--C(.dbd.0)--NR.sup.3 --NH.sub.2, with an acrylic prepolymer containing at least two different types of reactive functional groups, one of which is a hydroxyalkyl ester group and the other is carboxyl, anhydride, epoxy or isocyanate. LS is a light stabilizer moiety, and R.sup.3 is hydrogen, primary alkyl of 1 to 8 carbons, secondary alkyl of 3 to 8 carbons, aralkyl of 7 to 12 carbons or cycloalkyl of 5 to 12 carbons. The reaction may be carried out in an inert solvent or in the bulk state.The acrylic resins so produced with chemically bound light stabilizer groups are particularly useful in the stabilization of coatings. Enamel or lacquer coatings containing the polymer bound light stabilizer regins exhibit outstanding weatherability and durability.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: May 22, 1990
    Assignee: Pennwalt Corporation
    Inventors: Vasanth R. Kamath, James D. Sargent
  • Patent number: 4804775
    Abstract: An improved process is provided for preparing stable low viscosity polymer-polyols containing less than about 100 ppm residual monomers by using a monoperoxycarbonate initiator in combination with at least one initiator selected from diperoxyketals and peroxyesters, as chaser catalysts, at or near the end of the polymerization. The polymer-polyols prepared by the instant invention can be used to prepare high resiliency (load bearing) polyurethane foams.
    Type: Grant
    Filed: September 9, 1986
    Date of Patent: February 14, 1989
    Assignee: Pennwalt Corporation
    Inventors: Vasanth R. Kamath, Leonard H. Palys
  • Patent number: 4777230
    Abstract: A process is provided for the free radical polymerization of monomers derived from substituted or unsubstituted acrylic acid/methacrylic acid and esters thereof for the production of a polymer having a narrow molecular weight distribution and an average molecular weight of less than 4000. These polymers are produced by the solution polymerizing of said monomers wherein 20-40% by weight of the monomer composition is hydroxyalkyl acrylate or methacrylate in the presence of a solvent system suitable for high solids coating applications and in the presence of an initiating amount of a tertiary alkyl hydroperoxide and/or its derivatives having at least 5 carbons wherein the initiator and monomers, alone or in combination, are added continuously at a programmed rate wherein the rate of addition corresponds approximately to the rate of decomposition of said monomer and initiator. These polymers are used for high solids coating applications.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: October 11, 1988
    Assignee: Pennwalt Corporation
    Inventor: Vasanth R. Kamath
  • Patent number: 4219676
    Abstract: Unsymmetrical diperoxides of the general structure: ##STR1## for example, 4-(t-butylperoxycarbonyl)-3-hexyl-6-[7-(tbutylperoxycarbonyl)heptyl] cyclohexene, are useful for polymerizing ethylenically unsaturated monomers (such as styrene). The polymerizations can be carried out at higher temperatures and in shorter times than with conventional initiator systems, without detrimental decrease in polymer molecular weight or significant change in molecular weight distribution. The unsymmetrical diperoxides are also useful as catalysts for curing unsaturated polyester resins.
    Type: Grant
    Filed: January 16, 1978
    Date of Patent: August 26, 1980
    Assignee: Pennwalt Corporation
    Inventors: Jose Sanchez, Vasanth R. Kamath, James C. Halas
  • Patent number: 4219675
    Abstract: A batch process for the manufacture of liquid organic peroxides, such as peroxy esters and diacyl peroxides, by reacting an acid chloride, a hydroperoxide and an alkali metal hydroxide uses a countercurrent, packed distillation column for recovering a purer, drier product with higher yield than previous batch drying processes.
    Type: Grant
    Filed: February 6, 1979
    Date of Patent: August 26, 1980
    Assignee: Pennwalt Corporation
    Inventors: Ramdas Venkatram, Vasanth R. Kamath, Chester J. Smith
  • Patent number: 4167613
    Abstract: In the foaming of a polymerizable medium (such as an unsaturated polyester resin) by using acid sensitive azo compounds, significant improvement in the foaming efficiency can be obtained by incorporating in the resin medium 0.001%-10% by weight based on the weight of the resin compounds which exert an inhibiting effect on free radical polymerization. Examples of such compounds include methacrylonitrile, alphamethylstyrene and laurylmercaptan.
    Type: Grant
    Filed: June 5, 1978
    Date of Patent: September 11, 1979
    Assignee: Pennwalt Corporation
    Inventors: Ernest R. Kamens, Vasanth R. Kamath
  • Patent number: 4130700
    Abstract: A process for the free-radical polymerization of vinyl monomers, including vinyl aromatic monomers, at at least two distinct progressively higher polymerization temperatures, each between the temperatures of about 70.degree. C to about 150.degree. C in the presence of at least two free-radical initiators, one of which initiators, used in relatively minor proportions, has the formula ##STR1## wherein x is a numeral from 1 to 5 inclusive, B is ##STR2## A is hydrocarbyl, A, is tertiary hydrocarbyl and R is A, a hydrocarbyloxy or alkylperoxy and the other initiator, used in relatively major proportions, has a 10 hour half-life temperature below about 100.degree. C. The distinct temperatures for polymerization may occur as separate parts of a polymerization in which the temperature of the system continually increases.
    Type: Grant
    Filed: January 6, 1977
    Date of Patent: December 19, 1978
    Assignee: Pennwalt Corporation
    Inventor: Vasanth R. Kamath
  • Patent number: 4129703
    Abstract: A process for the free-radical polymerization of vinyl aromatic monomers in at least two thermally distinct polymerization stages each between the temperatures of about 70.degree. C and 150.degree. C in the presence of at least two free-radical initiators, one of which initiators is particularly effective at the lowest temperature stage and has the formula ##STR1## wherein R is an alkylene, alkynylene or alkenylene diradical, R.sub.1 is alkyl, alkenyl, alkyn or alkoxy and Rhd 2 is lower alkyl and R.sub.3 is hydrogen or a lower alkyl and a second of which initiators has a 10 hour half-life temperature of at least about 80.degree. C which temperature is at least about 15.degree. C above the 10 hour half-life temperature of the compound of the above formula.
    Type: Grant
    Filed: January 6, 1977
    Date of Patent: December 12, 1978
    Assignee: Pennwalt Corporation
    Inventors: Vasanth R. Kamath, Gary A. Harpell
  • Patent number: 4125695
    Abstract: A process for the free radical polymerization of vinyl monomers, including vinyl aromatic monomers, wherein the temperature of the polymerization is progressively increased by at least 30.degree. C during the period of the polymerization a temperature range of from 50.degree. C to 160.degree. C and wherein the final temperature is at least 110.degree. C, the polymerization mass including an initiator sensitive to produce free radicals near or at the low temperature end of the range and an initiator sensitive to produce free radicals near or at the high temperature end of the range. A single entity initiator may contain peroxide functions that are actuated to produce free radicals at each of the temperature extremes of the process.
    Type: Grant
    Filed: January 6, 1977
    Date of Patent: November 14, 1978
    Assignee: Pennwalt Corporation
    Inventor: Vasanth R. Kamath
  • Patent number: 4125696
    Abstract: A process for the free-radical polymerization of a vinyl monomer, including vinyl aromatic monomer, at least two distinct, progressively higher polymerization temperatures, each between the temperatures of from about 50.degree. C and 130.degree. C, in the presence of at least two free-radical initiators, one of which, used in relatively minor proportions, is di-t-butyl diperoxycarbonate and the other, used in relatively major proportions, has a ten hour half-life temperature below 90.degree. C. The distinct temperatures for polymerization may occur as separate parts of a polymerization in which the temperature of the system continually increases.
    Type: Grant
    Filed: January 6, 1977
    Date of Patent: November 14, 1978
    Assignee: Pennwalt Corporation
    Inventor: Vasanth R. Kamath