Patents by Inventor Kurt Hofer

Kurt Hofer 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: 3963737
    Abstract: 1,3-Dihydrocarbyl-pyrazole compounds, having a 5-hydroxyl group in free or nickel salt form, characterized by a ketoxyimino group bound directly to the 4-position of the pyrazole ring through the ketoxyimino functional carbon atom, which are useful as stabilizers of organic materials against the adverse effects of ultraviolet light.
    Type: Grant
    Filed: July 2, 1975
    Date of Patent: June 15, 1976
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer
  • Patent number: 3962175
    Abstract: The purpose of the invention are new benzene phosphonous acid compounds in which two to four benzene nuclei are bound together and which contain one to three phosphorus atoms. The new compounds are free acids, their salts with inorganic cations, their esters, thioesters or amides. The invention concerns also the manufacture of these benzene phosphonous acid compounds and their use for the stabilization of organic materials.
    Type: Grant
    Filed: April 25, 1974
    Date of Patent: June 8, 1976
    Assignee: Sandoz Ltd.
    Inventors: Kurt Hofer, Guenther Tscheulin
  • Patent number: 3959265
    Abstract: The present invention concerns novel nickel complexes (I) possessing U.V. stabilizing properties characterized by bearing per molecule 2 monodentate nickel coordinated 1,3-hydrocarbyl-4-(greater than C.sub.1)-acyl-pyrazole-5-oxy ligands and one bidentate or two monodentate nickel coordinated primary or secondary amine ligands, and their use as U.V. stabilizers for e.g. plastics materials.
    Type: Grant
    Filed: May 7, 1975
    Date of Patent: May 25, 1976
    Assignee: Sandoz Ltd.
    Inventors: Lajos Avar, Kurt Hofer
  • Patent number: 3957765
    Abstract: The present invention concerns novel aromatic heterocyclic hydrazide derivatives of the formula: ##SPC1##Wherein A is a radical ##SPC2##Wherein R.sub.1 is tertiary alkyl and R.sub.2 and R.sub.3 are hydrogen or substituents, e.g. alkyl, R.sub.4 is a group -X-R.sub.14.sub.' wherein X is a bridging function, e.g. O, and R.sub.14 is a substituent, e.g. alkyl, a heterocyclic group--N Zwherein Z, with the nitrogen atom, forms a heterocyclic ring or a radical -NH-A, wherein A is as defined above, R.sub.5 has inter alia one of the significances of R.sub.4 and Y is -N= or -CH=, which are useful antioxidants, e.g. for stabilizing plastics material.
    Type: Grant
    Filed: April 1, 1974
    Date of Patent: May 18, 1976
    Assignee: Sandoz Ltd.
    Inventors: Kurt Hofer, Guenther Tscheulin
  • Patent number: 3954847
    Abstract: The purpose of the invention are new benzene phosphonous acid compounds in which two to four benzene nuclei are bound together and which contain one to three phosphorus atoms. The new compounds are free acids, their salts with inorganic cations, their esters, thioesters or amides. The invention concerns also the manufacture of these benzene phosphonous acid compounds and their use for the stabilization of organic materials.
    Type: Grant
    Filed: April 25, 1974
    Date of Patent: May 4, 1976
    Assignee: Sandoz Ltd.
    Inventors: Kurt Hofer, Guenther Tscheulin
  • Patent number: 3948946
    Abstract: The invention provides novel cyclic acetals and mercaptals useful as stabilising agents for organic susceptible to degradation by heat or oxygen.
    Type: Grant
    Filed: September 20, 1974
    Date of Patent: April 6, 1976
    Assignee: Sandoz Ltd., (Sandoz AG)
    Inventors: Kurt Hofer, Anton Voykowitsch
  • 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
  • Patent number: 3935231
    Abstract: The present invention concerns benzothiophene acyl (2) derivatives of the formula, ##SPC1##Wherein R.sub.1, R.sub.2 and R are substituents and n is an integer 1 or 2.The compounds are useful as u.v. stabilizers for, e.g. plastic materials.
    Type: Grant
    Filed: October 11, 1973
    Date of Patent: January 27, 1976
    Assignee: Sandoz Ltd., (Sandoz AG)
    Inventors: Lajos Avar, Kurt Hofer