Patents by Inventor Kevin Lawson Birkett

Kevin Lawson Birkett 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: 4067865
    Abstract: Water-soluble azo dye which, in the form of the free acid, has the formula ##STR1## WHEREIN A represents lower alkyl, hydroxy lower alkyl or phenyl and R represents hydrogen, lower alkyl or hydroxy lower alkyl and A, when phenyl, and ring B is unsubstituted or substituted by nitro, alkyl or alkoxy, m has a value of 0 or 1 and E represents a residue selected from: ##STR2## wherein R.sup.5 represents hydrogen, lower alkyl, hydroxy lower alkyl or benzyl, R.sup.6 represents lower alkyl or hydroxy lower alkyl and R.sup.7 and R.sup.8 each independently represent hydrogen, lower alkyl, lower alkoxy or acetylamino; and ##STR3## WHEREIN R.sup.9 represents lower alkyl, hydroxy lower alkyl, sulphato lower alkyl, phenyl or phenyl substituted by lower alkyl, lower alkoxy or hydroxy and p has a value of 0 or 1 with the proviso that there are no more than two sulpho groups in said dye. The dye is useful to color natural and synthetic polyamide textile materials.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: January 10, 1978
    Assignee: Imperial Chemical Industries Limited
    Inventors: Kevin Lawson Birkett, John Alexander Bone, Denis Robert Annesley Ridyard