Hair colorant products (non-oxidative)

Description

The coloration which can be achieved by non-oxidative colorant products (often designated as hair tints) is not permanent. The applied dyes are washed out after six to eight hair washes. The achievable hair colour is a result of the combined effects of the applied color shade and the natural (previous) hair colour. It is not possible to obtain lighter colour shades than the previous hair colour. Hair damage is minimal as compared to effects from oxidative colorant products. The dyes used (eg triphyenyl methane, anthraquinone, azo- or aromatic nitro dyes) have a high affinity to the hair keratin and bind superficially to the outer cuticle layer of hair or penetrate into the cuticle (valid in particular for nitro dyes). Non-oxidativehair colorant products are frequently marketed as cream formulations. Liquid tints are applied as lotion or balm predominantly by hairdressers and often have to be diluted for application. They are applied after the hair wash to the well rinsed, towel-dry hair and rinsed out again after the recommended exposure time. Shampoos or hair conditioners (as cream or mousse preparations) are considered to be particularly conveniant for application. Like the tints they are based on surfactants (eg non-ionic, cationic, anionic or amphoteric surfactants). Rather weak colour changes can be obtained with colorant setting lotions. In this case the dyes do not penetrate into the hair, but envelop the hair superficially as a film just like the styling polymers. This film is, however, readily removed during shampooing. Colorant setting lotions are mostly offered as aqueous alcoholic solutions with cationic dyes.