Azomethine dye solutions
AssigneeE. I. Du Pont de Nemours and Company
InventorRay Allen Clarke
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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.
Claims8
A stable, yellow, basic azomethine dye solution comprising
- 5% to 50% by weight of dye,
- 10% to 95% by weight of at least one member selected from the group consisting of carboxylic acids of one to six carbon atoms, and water-soluble hydroxycarboxylic acids, and
- 0 to 40% by weight of water, the dye having the formula ##SPC2##
- wherein A is phenyl or phenyl substituted by 1 to 3 groups selected from C.sub.1-4 alkyl and C.sub.1-4 alkoxy.
Dependencies are inferred from the claim text.