| abstract |
Keratinous substances, e.g. hair, are dyed and simultaneously permanently waved with a solution at pH 8-9.6 comprising thioglycollic, thiosuccinic or thiolactic acid or their alkali metal, ammonium or ethanolamine salt in an amount equivalent to 1-7% on the weight of solution calculated as thioglycollic acid, 1-5% of urea or thiourea and/or 0.1-1% of a proteolytic enzyme and 0.5-5% of a metal containing dyestuff. The preferred dyes, are chromium complexes of o,o\sv-dihydroxyazo dyes containing -SO3H groups. The hair may be after-treated with an aqueous solution of an organic acid at pH 3-4 which may contain an oxidising agent, e.g. H2O2 or potassium bromate. The specified proteolytic enzymes are pepsin, papain and phytin. The dye compositions may be applied at 20-25 DEG C and they may further contain alkalis, e.g. ammonia or ethanolamines, sodium alkylbenzene sulphonates, alkylolamides, propylene glycol, glycerine, isopropyl alcohol and oleic or stearic acid. Examples are given. |