Acid donor process for dyeing polyamide fibers and textiles
AssigneeSybron Chemicals, Inc.
InventorsRobert B. Login, Calvin McIntosh Wicker, Jr., Otto Bella
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Abstract
A process for dying materials containing natural or synthetic polyamides is disclosed. The process includes immersing the materials to be dyed in a dye bath containing an acid dye. The pH of the dye bath is initially at a level that substantially inhibits the dye from being absorbed by the polymer. In accordance with the present invention, however, an acid producing composition is added to the bath which gradually reduces the pH of the bath and allows for uniform diffusion of the dye into the polymer. The acid producing composition of the present invention is a maleate ester, which, in one embodiment, is the reaction product of maleic acid or maleic anhydride and a glycol.
Claims29
A process for dyeing a material containing a synthetic or natural polyamide, said process comprising the steps of:
- contacting said material with an aqueous dye bath containing an acid dye, said dye bath having an initial pH that inhibits said acid dye from bonding to said polyamide contained in said material;
- adding to said dye bath an acid producing agent, said acid producing agent comprising a maleate diester, said acid producing agent being added to said dye bath in an amount sufficient to lower the pH of said bath thereby causing said acid dye to bind to said polyamide contained within said material.
A process for dyeing a textile material containing a synthetic or natural polyamide, said process comprising the steps of:
- contacting said textile material with an aqueous dye bath containing an acid dye;
- adding to said dye bath an acid producing agent, said acid producing agent comprising an esterified maleate having the following formula:
- ##STR5## wherein R.sub.1 results from a glycol and R.sub.2 results from a glycol or a lower alkyl alcohol, said acid producing agent being added to said dye bath in an amount sufficient to lower the pH of said bath for causing said acid dye to bind to said polyamide contained within said textile material.
A process for dyeing a material containing a synthetic or natural polyamide, said process comprising the steps of:
- contacting said material with an aqueous dye bath containing an acid dye;
- adding to said dye bath an acid producing agent, said acid producing agent comprising a diesterified maleate, said maleate being diesterified by a substantially water soluble glycol, said acid producing agent being added to said dye bath in an amount sufficient to gradually lower the pH of said bath to a point where said acid dye bonds to said polyamide contained within said material.
A dye bath for dying polyamide materials comprising an aqueous solution containing an acid dye and a maleate diester, said maleate diester consisting essentially of a reaction product of maleic acid or maleic anhydride and a glycol.
Dependencies are inferred from the claim text.