Patents by Inventor Paul Kerwin

Paul Kerwin 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).

  • Azo lake pigment composition
    Patent number: 6402828
    Abstract: Pigment composition which comprises azo pigments and auxochromes. The composition is prepared in-situ by coupling an aromatic diazonium compound with 3-hydroxy-2-naphthoic acid and can be produced in a fixed quality with excellent reproducibility, transparency, a high color strength, clear and vivid hue and good water resistance.
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: June 11, 2002
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Greig Chisholm, Paul Kerwin, Mairi Nicol
  • Production process
    Patent number: 6031030
    Abstract: A process for the preparation of a paint concentrate which comprises(a) milling or acid pasting a crude metal phthalocyanine to reduce the particles size thereof, thereby forming a modified crude metal phthalocyanine and(b) kneading a mixture of the modified crude metal phthalocyanine together with a paint vehicle comprising one or more paint solvents, the metal phthalocyanine being present in an amount of 20 to 80% by weight of the kneaded mixture, to give a paint concentrate containing the metal phthalocyanine in pigmentary form dispersed in the paint vehicle.
    Type: Grant
    Filed: May 14, 1998
    Date of Patent: February 29, 2000
    Assignee: Ciba Speicialty Chemicals Corporation
    Inventors: Robert Langley, Paul Kerwin, Arthur Stark Walls, Kenneth Grant Dykes
  • Pigment compositions
    Patent number: 6007612
    Abstract: The present invention provides the use of a resinated pigment in which from 10 to 100% of the resinated proportion of the product is a resin ester, as colourant in a lithographic printing ink.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: December 28, 1999
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Paul Kerwin, David McGregor, John Bryce Blackburn
  • Process for the production of ink concentrates
    Patent number: 5964929
    Abstract: A process for the preparation of an ink concentrate which comprises(a) milling a crude metal phthalocyanine to reduce the particle size thereof, thereby forming a modified crude metal phthalocyanine and(b) kneading a mixture of the modified crude metal phthalocyanine together with an ink vehicle comprising one or more ink solvents, the metal phthalocyanine being present in an amount of 20 to 80% by weight of the kneaded mixture, to give an ink concentrate containing the metal phthalocyanine in pigmentary form dispersed in the ink vehicle.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: October 12, 1999
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Robert Langley, Paul Kerwin, Arthur Stark Walls, Kenneth Grant Dykes
  • Production of pigments
    Patent number: 5776238
    Abstract: The present invention provides a process for converting a crude pigment into pigmentary form which comprises kneading the crude pigment in the presence of a liquid carboxylic acid and optionally a salt.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: July 7, 1998
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Paul Kerwin, Robert Langley, Arthur Stark Walls