Patents by Inventor Ray Allen Clarke

Ray Allen Clarke 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).

  • Process for making yellow, basic azomethine dyes
    Patent number: 4092104
    Abstract: A process for making yellow, basic azomethine dyes for paper, leather and textiles; the process being an improvement in the process of reacting an azo dye base precursor of the formula ##STR1## wherein A is phenyl or substituted phenyl, with dimethyl sulfate in solution, and in the presence of an acid-binding agent, the improvement comprising reacting dimethyl sulfate in a molar excess of from 100% to 300% per mole of precursor, in an aqueous solution having at least 30 weight percent water and from 2.0 to 3.5 moles of magnesium oxide (as the acid-binding agent) per mole of precursor.
    Type: Grant
    Filed: March 22, 1976
    Date of Patent: May 30, 1978
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Ray Allen Clarke
  • Azomethine dye solutions
    Patent number: 3973903
    Abstract: A process for making yellow, basic azomethine dyes for paper, leather and textiles, and concentrated, stable solutions thereof; the process being an improvement in the process of reacting an azo dye base precursor of the formula ##SPC1##Wherein A is phenyl or substituted phenyl, with dimethyl sulfate in solution, and in the presence of an acid-binding agent,THE IMPROVEMENT COMPRISING EMPLOYING AN AQUEOUS SOLUTION HAVING AT LEAST 30 WEIGHT PERCENT WATER, EMPLOYING DIMETHYL SULFATE IN A MOLAR EXCESS OF FROM 100% TO 300%, AND EMPLOYING FROM 2.0 TO 3.5 MOLES OF MAGNESIUM OXIDE AS THE ACID-BINDING AGENT PER MOLE OF PRECURSOR.
    Type: Grant
    Filed: March 5, 1974
    Date of Patent: August 10, 1976
    Assignee: E. I. Du Pont de Nemours and Co.
    Inventor: Ray Allen Clarke