NOVEL PERMANENT HAIR COLORING SYSTEMS DELIVERING COLOR WITH REDUCED FIBER DAMAGE

摘要

Use of permanent hair colorants is widespread and allows the consumer to either change their natural hair celor and/or cover gray. However, there are trade-offs that the consumer has to make if she is using these products on a regular basis. One of the main trade-offs is the fiber damage that is sometimes seen over multiple uses. This can lead to the consumer experiencing poor hair feel, an increased incidence of split ends and generally hair that loses some of its healthy appearance and shine. Thus developing hair colorant systems that allow the consumer to color on a more regular basis yet maintain hair quality is highly desirable.rnThere are two key chemical processes that take place during the coloring process. The first is the oxidation of the melanin pigment and previously deposited dyes that lightens the underlying hair color and the second is the oxidation of the dye precursors to form the coloured chromophores. For both processes the oxidant is essential and in the majority of retail hair colorants the oxidant used is the combination of hydrogen peroxide with an ammonia alkalizer at a final pH of 10. Importantly, it is also the oxidant that is mainly responsible for the damage to the hair fiber which leads to the loss of the hair's strength and healthy appearance.