Patents by Inventor Tyler A. Stevenson

Tyler A. Stevenson 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: 5942626
    Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: August 24, 1999
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Roland A.E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5849821
    Abstract: Selected s-triazines of formula I ##STR1## where G.sub.1 and G.sub.2 are biphenylyl moieties, are UV absorbers having high thermal stability and surprisingly high extinction coefficients making them of especial interest in stabilizing automotive coatings where such properties are highly valued.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: December 15, 1998
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Tyler A. Stevenson, Revathi Iyengar, Ramanathan Ravichandran
  • Patent number: 5726309
    Abstract: The s-triazines of formula I are UV absorbers having high thermal stability and surprisingly high extinction coefficients making them of especial value for stabilizing polymer subsnates, especially automotive coatings.Tris-aryl-s-triazines in which at least one of the aryl groups has an hydroxy group ortho to the point of attachment to the triazine ring are well known UV absorbers. It is also well-known that this class of triszines protect organic polymers from the deleterious effects of exposure to actinic radiation.The instant invention pertains to novel dimetic or oligomeric tris-aryl-s-triazines wherein at least one of the aryl groups is a biphenylyl or substituted biphenylyl moiety.More particularly, the instant invention relates to compounds of formula I ##STR1## wherein G.sub.1, G.sub.2, and E.sub.2 are here-in-below defined.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: March 10, 1998
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Tyler A. Stevenson, Revathi Iyengar, Ramanathan Ravichandran
  • Patent number: 5637706
    Abstract: Tris-aryl-s-triazines of formula I, II or III ##STR1## which contain from one one to three resorcinol derived moieties with at least one of said moieties substituted in the 5-position with a phenylalkyl group have UV spectra which are red-shifted to the near UV range and provide excellent stabilization to polymeric substrates against the deleterious effects of actinic light.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: June 10, 1997
    Assignee: Ciba-Geigy Corporation
    Inventors: Tyler A. Stevenson, Ramanathan Ravichandran, Mark S. Holt, Thuy N. Phan, Jean-Luc Birbaum, Vien V. Toan
  • Patent number: 5585422
    Abstract: s-Triazine UV absorbers substituted by a benzotriazolyl or benzophenonyl moiety exhibit unexpectedly improved UV absorption characteristics and outstanding efficacy in protecting organic substances from the deleterious effects of actinic radiation as well as good resistance to loss by volatilization during processing of stabilized compositions at elevated temperatures.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: December 17, 1996
    Assignee: Ciba-Geigy Corporation
    Inventors: Robert A. Falk, Tyler A. Stevenson, Gregory R. Coughlin
  • Patent number: 5556973
    Abstract: Tris-aryl-s-triazines which contain from one to three resorcinol derived moieties with at least one of said moieties substituted at the 5-position with an alkyl, phenylalkyl, halogen, thio or sulfonyl group have UV spectra which are red-shifted to the near UV range and provide excellent stabilization to polymeric substrates against the deleterious effects of actinic light.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: September 17, 1996
    Assignee: Ciba-Geigy Corporation
    Inventors: Tyler A. Stevenson, Ramanathan Ravichandran, Mark S. Holt, Thuy N. Phan, Jean-Luc Birbaum, Vien V. Toan
  • Patent number: 5543518
    Abstract: Tris-aryl-s-triazines which contain from one to three resorcinol derived moieties with at least one of said moieties substituted at the 5-position with an alkyl, phenylalkyl, halogen, thio or sulfonyl group have UV spectra which are red-shifted to the near UV range and provide excellent stabilization to polymeric substrates against the deleterious effects of actinic light.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: August 6, 1996
    Assignee: Ciba-Geigy Corporation
    Inventors: Tyler A. Stevenson, Ramanathan Ravichandran, Mark S. Holt, Thuy N. Phan, Jean-Luc Birbaum, Vien V. Toan
  • Patent number: 5516914
    Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: May 14, 1996
    Assignee: Ciba-Geigy Corporation
    Inventors: Roland A. E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5476937
    Abstract: Tris-aryl-s-triazine UV absorbers typified by those of formula B or C ##STR1## wherein X and L each possess a sulfur-containing moiety, provide excellent light stability protection to electro coat, base coat or clear coat finishes.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: December 19, 1995
    Assignee: Ciba-Geigy Corporation
    Inventors: Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5436349
    Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a sulfoxide or sulfone group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: July 25, 1995
    Assignee: Ciba-Geigy Corporation
    Inventors: Roland A. E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5354794
    Abstract: Tris-aryl-s-triazine UV absorbers typified by those of formula A or B ##STR1## provide excellent light stability protection to electro coat, base coat or clear coat finishes.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: October 11, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5280124
    Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a sulfoxide or sulfone group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
    Type: Grant
    Filed: February 5, 1992
    Date of Patent: January 18, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: Roland A. E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
  • Patent number: 5278314
    Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
    Type: Grant
    Filed: February 5, 1992
    Date of Patent: January 11, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: Roland A. E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran