0 - 0 +:: C) C C) C cu (.) 'I,... 0 0 (.) NOVEL ACID-TYPE HAIR COLOR TECHNOLOGY 41 105 95 85 75 0 10 20 30 Times of shampoo Figure 8. Shampoo resistance test of "permanent" acid-type hair color. The closed square (■), diamond ( ♦ ), and triangle ("-) represents the color-changing ratio of "permanent" acid-type, conventional oxidative, and conventional acid-type hair color, respectively. The color change ratio of novel acid hair color was better than not only that of conventional acid hair color but also conventional oxidative hair color. The color­ changing ratio was evaluated by the following equation: Color changing ratio ( % ) = [LlEwashed ha i..J / [LlEdyed ha ir} X 100 where LlEdyed hair and LlEwashcd hair represent LlE immediately after dyeing and washing, respectively. acid-type hair color can keep the dye firmly in the hair. By this method, the color longevity effect of the "permanent" acid-type hair color was verified against conventional shampoo as well as 2% SDS. VERIFICATION OF FORMATION OF DYE-METAL ION COMPLEX The data show the peak absorbance of acid red 52 (565 nm) and acid orange 7 (485 nm) of each sample. The elution of acid red 52 and acid orange 7 of conventional acid-type hair color had no dependence on the concentration of EDTA, but that of the "perma­ nent" acid-type hair color had dependence on the concentration of EDTA-2Na (Figure 9). This result indicates that the aluminum ion of the dye-metal complex formed a chelate with EDTA and the released dyes were extracted. FLUORESCENT X-RAY ANALYSIS OF THE STATE OF THE ALUMINUM ION OF DYE-METAL COMPLEX The degree of difference of photon energy (�e V) between the sample and Al 2 O 3 was investigated. The fluorescent X-ray spectra of Al-Hair, Al-Hair-Dye, and Al-Dye are shown in Table VII. Since the Al-K 13 of Al-Dye and Al-Hair was completely different, this difference was caused by the difference of bond energy between Al-Dye and Al-Hair.

42 JOURNAL OF COSMETIC SCIENCE Acid red 52 extraction 2.5 2 � 1.5 { 0.5 0 0 0.1 0.5 2 EDTA·2Na concentration(%) 3.5 3 2.5 E C: 2 1.5 .a { 0.5 0 Acid orange 7 extraction 0 0.1 0.5 2 EDTA·2Na concentration(%) Figure 9. Formation of the dye-metal ion complex inside hair treated by the "permanent" acid-type hair color. The amount of the dye extracted by EDTA form hair was monitored. The dotted and hatched columns represent the absorption of dye from hair dyed with a conventional acid-type hair color and "permanent" acid-type hair color, respectively. The elution of acid red 52 and acid orange 7 of conventional acid-type hair color had no dependence on the concentration of EDT A, but that of "permanent" acid-type hair color had dependence on the concentration of EDTA-2Na. Table VII Fluorescent X-ray Analysis of the State of the Aluminum Ion of Dye-Metal Complex Sample Al-Dye Al-Hair-Dye Al-Hair Photon energy (de V) -1.01 -0.19 -0.32 The degree of difference of photon energy between sample and Al2O3 was investigated. Al-Dye, Al-Hair, and Al-Hair-Dye represent a complex of A1Cl3 ·6H2O and acid orange 7 AlC13 ·6H2O, hair protein, and acid orange 7 and A1Cl3 ·6H2O with hair protein, respectively. The K� spectrum of Al-Hair-Dye was different from that of both Al-Dye and Al-Hair. If it was thought that the combination of both states existed, the K� spectrum is supposed to be the same as the K� spectrum of Al-Dye or Al-Hair. However, actually, the Al-K� of Al-Hair-Dye was different from that of both Al-Dye and Al-Hair. It suggests that the aluminum ion of Al-Hair-Dye binds with both acid orange 7 and hair protein. NMR ANALYSIS OF THE STATE OF BOND The NMR spectra of Dye, Al-Dye, and Al-Dye-EDTA are shown in Figures lOA-lOC. Small peaks indicated by arrowheads appear in Figure lOB. In contrast, the small peaks disappear in Figure lOC. These small peaks are considered to result from chelate between