Method for temporarily coloring article with acid labile colorant
OwnerJohn B. Hines, John G. Leverinventors
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Abstract
An article may be temporarily colored by application of an aqueous solution of a polyoxyalkylene substituted chromophore characterized by a N.dbd.pair with an electron withdrawing group bonded to one element of the pair and an electron donating group bonded to the opposite element. The polyoxyalkylene substituent imparts solubility to the colorant and bulk to prevent penetration into interstices in the article being colored. The colorant may be subsequently decolorized in hydrolysis when an aqueous acid solution is applied to the colorant.
Claims36
A process for providing temporary coloration to an article, comprising the steps of:
- applying a solution of a colorant to an article in an amount sufficient to provide coloration to said article, wherein said colorant is a polyoxyalkylene-substituted chromophore and said chromophore is selected from azomethine and indophenol chromophores, said chromophore further having a carbon-nitrogen pair joined by a double bond and characterized by an electron withdrawing group bonded to one element of said pair and an electron donating group bonded to an opposite element of said pair and said polyoxyalkylene substitutent is a straight or branched polymer chain having at least 10 monomer units selected from ethylene oxide, propylene oxide and glycidol;
- maintaining said application of said colorant to provide coloration of said article for a desired length of time;
- and
- hydrolyzing said carbon-nitrogen pair of said chromophore by contacting said colorant with an aqueous acid having a pH of five or less to extinguish said colorant.
A process for providing temporary coloration to an article, comprising the steps of:
- applying a solution of a colorant to an article in an amount sufficient to provide coloration to said article, wherein said colorant is selected from compounds of the formula:
- ##STR36## wherein A is a polyoxyalkylene substituent having a straight or branched polymer chain of at least 10 monomer units selected from ethylene oxide, propylene oxide, and glycidol;
- maintaining said application of said colorant to provide coloration of said article for a desired length of time;
- and
- hydrolyzing said carbon-nitrogen pair of said chromophore by contacting said colorant with an aqueous acid having a pH of five or less to extinguish said colorant.
A process for providing temporary coloration of a textile fiber comprising the steps of:
- applying a solution of a colorant to said fiber in an amount sufficient to provide coloration to said fiber, wherein said colorant is a polyoxyalkylene-substituted chromophore and said chromophore is selected from azomethine and indophenol chromophores, said chromophore further having a carbon-nitrogen pair joined by a double bond and characterized by an electron withdrawing group bonded to one element of said pair, wherein said electron withdrawing group is selected from NO.sub.2, CN, cyanophenyl, nitrophenyl, alkyl ester, ketone, aryl ester, aldehyde, sulfonic acid, carboxylic acid, ammonium ion and vinyl ketone groups, and an electron denoting group bonded to an opposite element of said pair, wherein said electron donating group is selected from arylamine, arylalkoxide and alkylaryl groups, and said polyoxyalkylene substituent is a straight or branched polymer chain having at least 10 monomer units selected from ethylene oxide, propylene oxide and glycidol;
- allowing said colorant to remain on said fiber for a sufficient length of time to identify said fiber based upon said coloration;
- and
- hydrolyzing said carbon-nitrogen pair of said chromophore by contacting said colorant with an aqueous acid having a pH of five or less to decolorize said colorant.
Dependencies are inferred from the claim text.