Natural colourant prepd. by solvent extn. of leguminous plants - of specified Pterocarpus and Dalbergia species, used as hair dyes

摘要

The prepn. comprises solvent extn. of the ligneous tissues of leguminous plants selected from Pterocarpus indicus, P. santalinus, P.macrocarpus, P.dabbergioides, P. tinctoria, P. santalinoides, Dalbergia sissoo, D. latifolia, D. melanoxylon followed by concn. of the extract. Pref. solvents are 1-3C alcohols, 3-5C ketones, 3-6C esters, 1-2C halohydrocarbons and mixtures of these or an aq. basic soln. The colourant is pref. concentrated by evaporation of the soln. on a polyol, an oil or fat or a surfactant. The extract is particularly used in hair dyeing compsns. as well as having remarkable dyeing properties, the colourants have antibacterial properties.