1.  Field of the Invention
This invention relates to compositions for preventing the fading of artificial hair dye and/or slowing down the oxidation of hair, and more particularly, to a cationic phenol antioxidant for achieving this result effectively. 
2.  Description of the Prior Art
Hair comprises predominantly certain polypeptide chains that are held together by disulfide bonds that link adjacent polypeptide chains.  These bonds are formed from two cysteine amino acid residues on the adjacent keratin polypeptides.  The disulfide bonds impart its mechanical strength and extensibility to the hair.  However, exposure to sun tends to cause these disulfide bonds to break, predominantly on the outer surface of the hair and the outer surface of the hair cuticle.  This effect makes the hair stiff and brittle in dry weather and frizzy in humid weather.  The hair also loses its color and luster. 
Photofilters or UV-absorbers have been employed in cosmetic products for many years to protect coloring dyes from photofading.  Recently, sunscreens also have been added to hair care products to guard against the deleterious effects of solar irradiation on the hair. 
Photoprotection of melanin in skin has been intensively investigated over the last years.  For hair protection, several approaches have been described, such as the deposition of photofilters on the hair surface, and the use of antioxidants, or free radical scavengers.  See W. P. Smith and F. J. Penna, U.S. Pat.  No.  4,786,493. 
Accordingly, it is an object of the present invention to provide new and improved compositions for preventing the fading of artificial hair dye on the hair of the user and/or slowing down the oxidation of hair.