| 摘要 |
<p>Compsn. contains in a cosmetic medium as oxidn. colourant p-phenylenediamine (PPD) or its salts and o-aminophenol (OAP) or its salts in a PPD/OAP mol. ratio such that after addn. of an equal vol. of 20 vol. H2O2 and application to the hair for 30 mins., no Bandrowsky base is detected in the oxidising compsn. (formed by oxidative self-coupling of PPD). - Partic. embodiments for (a) dark shades and (b) light to medium shades are (a) 1-2.5% PPD and PPD/OAP up to 2 and (b) less than 1% PPD and PPD/OAP up to 3. In the hair dyeing process an alternative is to apply an OAP contg. compsn. first followed by a compsn. contg. PPD. - A novel cpd. is formed by oxidative coupling of PPD and OAP which is 2-amino-5-(p-aminoanilino)-N- (p-aminophenyl)-1, 4-benzoquinone imine (I). The compsn. enables a satisfactory depth of shade with inhibition of Bandrowsky base formation, cpd. (I) being formed instead. DEAB- DE3025992 C Hair tinting compsn. comprises 1,4-diaminobenzene or a nontoxic salts, (1-2.5 or 0.2-1.0wt.%) and 2-aminophenol or a nontoxic salt (0.5-1.0 or 0.33-1.0 mol phenylenediamine), dispersed with the usual carriers and opt. additives.</p> |
