Patents by Inventor John B. Henshall

John B. Henshall 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: 5166350
    Abstract: A process for the preparation of a fluoran compound of the formula ##STR1## wherein R, R.sub.1, R.sub.2 and R.sub.4 are each independently hydrogen, halogen, lower alkyl or lower alkoxy,R.sub.3 is hydrogen, halogen, lower alkyl, lower alkoxy or --NX.sub.3 X.sub.4, or (R.sub.1 and R.sub.2) or (R.sub.3 and R.sub.4) each pair together with the carbon atoms to which they are attached, form a fused benzene nucleus,X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are each independently hydrogen, alkyl containing not more than 12 carbon atoms which is unsubstituted or substituted by cyano, halogen, hydroxy, tetrahydrofuryl or lower alkoxy, or are cycloalkyl, aryl or aralkyl or (X.sub.1 and X.sub.2) or (X.sub.3 and X.sub.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: November 24, 1992
    Assignee: Ciba-Geigy Corporation
    Inventors: Davor Bedekovic, Jerry L. Pool, Brian J. Williams, Robert Garner, John B. Henshall
  • Patent number: 4533499
    Abstract: A process for the production of a compound of formula ##STR1## which comprises reacting a compound of formula ##STR2## or a mixture of the compounds (2a) and (2b) with a compound ZH or a compound of formula ##STR3## or a mixture of the compounds (2c) and (2d) with a compound YH, both reactions under acidic conditions, wherein X and Y are the same or different and each represents an aromatic carbocyclic radical having an unsubstituted or substituted amino group in the para position to the indicated bond, or a heterocyclic group, and Z represents an aryl radical of formula ##STR4## wherein R.sub.1 and R.sub.2 independently of one another represent hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.8 -alkoxyalkyl, cycloalkyl, aralkyl, aryl, or substituted alkyl, cycloalkyl, aralkyl or aryl, or R.sub.1 and R.sub.
    Type: Grant
    Filed: April 6, 1984
    Date of Patent: August 6, 1985
    Assignee: Ciba-Geigy Corporation
    Inventors: Malcolm C. Clark, John B. Henshall, Derrick A. Hart
  • Patent number: 4348330
    Abstract: A process for the production of a sulphinate of formula ##STR1## which comprises reacting a compound of formula ##STR2## or a mixture of the compounds of formulae (2a) and (2b) with a compound of formulaY--SO.sub.2 --M (3)in an organic solvent in the presence of a mineral acid or organic acid and, optionally, also of water, wherein Ar.sub.1 and Ar.sub.2 are the same or different and each represents an unsubstituted or substituted aromatic carbocyclic radical.R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently of one another represent hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.2 -C.sub.8 -alkoxyalkyl, cycloalkyl, aralkyl, aryl, or substituted alkyl, cycloalkyl, aralkyl or aryl, or each of the pairs of substituents (R.sub.1 and R.sub.2) and (R.sub.3 and R.sub.4), together with the nitrogen atom to which said pair is attached, independently, represents a heterocyclic ring, or one of several of the substituents R.sub.1, R.sub.2, R.sub.3 and R.sub.4 with the nitrogen and an adajcent carbon atom of the residue Ar.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: September 7, 1982
    Assignee: Ciba-Geigy Corporation
    Inventors: Malcolm C. Clark, John B. Henshall
  • Patent number: 4072690
    Abstract: Indolyl methylene leuco dyestuffs of the formula ##STR1## wherein X.sub.1 and X.sub.2 independently of the other, represent alkyl with 2 to 12 carbon atoms, alkenyl with at most 12 carbon atoms or phenylalkyl with 1 to 4 carbon atoms in the alkyl part, Y.sub.1 and Y.sub.2 independently of the other, represent hydrogen, alkyl with 1 to 12 carbon atoms or phenyl, Z represents alkyl with 1 to 12 carbon atoms, alkenyl with at most 12 carbon atoms, aryl, aralkyl or a heterocyclic residue and the rings A and B may be further substituted by cyano, nitro, halogen, alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms or acyl with 1 to 8 carbon atoms, said methylene compounds are particularly useful as slow developing color formers in pressure-sensitive recording material and exhibit good light and air stability.
    Type: Grant
    Filed: January 23, 1975
    Date of Patent: February 7, 1978
    Assignee: Ciba-Geigy Corporation
    Inventors: Robert Garner, John B. Henshall, Jean-Claude Petitpierre