Patents by Inventor Martin Preiswerk

Martin Preiswerk 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).

  • Pyrazole compounds as stabilizers for organic materials
    Patent number: 4146540
    Abstract: The present invention concerns certain novel compounds falling under the general formula: ##STR1## WHEREIN R.sub.1, R.sub.2 and R.sub.3 are substituents, e.g. alkyl and Me is hydrogen or a metal cation.The compounds are useful stabilizers of organic material against the degradative effect of heat, oxidation and U.V. light.
    Type: Grant
    Filed: October 21, 1977
    Date of Patent: March 27, 1979
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer, Martin Preiswerk
  • Pyrazole derivatives
    Patent number: 4102857
    Abstract: New ultraviolet light-absorbing compounds of the formula ##STR1## IN WHICH R.sub.1 is a substituent, e.g. alkyl,R.sub.2 is a substituent, e.g. alkyl,R.sub.3 is hydrogen or a substituent, e.g. alkyl,N is 1, 2 or 3, andR is an n-valent, optionally substituted benzene radical, or a 1- or 2-valent naphthalene or heterocyclic radical, which are producible by known processes. Such compounds are useful as stabilizers of organic materials, particularly plastics materials, against the degrading action of ultraviolet light and can be either applied as a coating on the organic material, or incorporated therein.Such compounds are useful as stabilizers of organic materials, particularly plastics materials, against the degrading action of ultraviolet light and can be either applied as a coating on the organic material, or incorporated therein.
    Type: Grant
    Filed: August 20, 1976
    Date of Patent: July 25, 1978
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer, Martin Preiswerk
  • Method of stabilizing organic materials employing pyrazole compounds and stabilized compositions thereof
    Patent number: 4008200
    Abstract: The present invention concerns a novel method of stabilizing organic material susceptible to degradation under the effect of heat, oxidation or ultra-violet light which comprises treating said material with a compound of the formula: ##STR1## WHEREIN R.sub.1, R.sub.2 and R.sub.3 are substituents, e.g. alkyl and Me is hydrogen or a metal cation.
    Type: Grant
    Filed: April 11, 1975
    Date of Patent: February 15, 1977
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer, Martin Preiswerk
  • Pyrazole derivatives
    Patent number: 3976658
    Abstract: New ultraviolet light-absorbing compounds of the formula ##SPC1##In whichR.sub.1 is a substituent, e.g. alkyl,R.sub.2 is a substituent, e.g. alkyl,R.sub.3 is hydrogen or a substituents, e.g. alkyl,n is 1, 2 or 3, andR is an n-valent, optionally substituted benzene radical, or a 1- or 2-valent naphthalene or heterocyclic radical,Which are producible by known processes.Such compounds are useful as stabilizers of organic materials, particularly plastics materials, against the degrading action of ultraviolet light and can be either applied as a coating on the organic material, or incorporated therein.
    Type: Grant
    Filed: July 8, 1974
    Date of Patent: August 24, 1976
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer, Martin Preiswerk
  • Organic compounds
    Patent number: 3936479
    Abstract: The present invention concerns benzophenone compounds of the formula: ##SPC1##WhereinR.sub.1, r.sub.2, r.sub.3 and R.sub.4 are hydrogen or substituents, e.g. alkyl,X is a mono-, di- or trivalent radical andn is an integer 1, 2 or 3.The compounds are useful as U.V. stabilizers for, for example, plastics materials.
    Type: Grant
    Filed: May 4, 1973
    Date of Patent: February 3, 1976
    Assignee: Sandoz Ltd., (Sandoz AG)
    Inventors: Lajos Avar, Kurt Hofer, Martin Preiswerk