Abstract: A permanent wave method includes a first step of applying a reducing agent (12) to hair (10) to be permed. At this point of time the hair (10) is not yet curled around a rod and is still straight. Then, the hair is covered with a cap of vinyl, and is left in this condition until the hair is brought into a first reduced condition in which the hair is sufficiently soft and plastic to be wrapped around a rod without cracking or straining. Thereupon, the reducing agent remaining on the hair is washed away. Then, the hair is wrapped, or curled, around a rod (13), and is covered with a vinyl cap (16). Thereupon, the hair is heated in its entirety, from its root up to its end. As a result, the hair is brought into a second reduced condition in which the hair is locked in the curled pattern about the rod (13). Then, cap (16) is removed. Then, an oxidizing agent (17) is applied to the hair, and is left in this condition until the hair has been locked into a more stable curled pattern.

Abstract: In the purification of crude tetrachlorophthalic anhydride containing hexachlorobenzene as impurities, this invention relates to purification by decomposition in which crude tetrachlorophthalic anhydride is contacted with chlorine gas in fuming sulfuric acid or sulfuric anhydride in the presence of iodine or iodine trichloride to decompose the impurities and remove them or purification by washing in which hexachlorobenzene is separated by washing with a chlorinated solvent. This invention also relates to a process for purifying crude tetrachlorophthalic anhydride containing iodotrichlorophthalic anhydrides as impurities by applying a radical reaction treatment in a chlorinated solvent to convert iodotrichlorophthalic anhydrides to tetrachlorophthalic anhydride. Moreover, it relates to high-purity tetrachlorophthalic anhydride containing 10 ppm or less of hexachlorobenzene.