Deposition of 18-MEA onto alkaline-color-treated weathered hair to form a persistent hydrophobicity.
A technology for the deposition of a persistent hydrophobicity to alkaline-color-treated weathered hair surfaces using 18-MEA (18-methyleicosanoic acid) is presented. Two approaches were examined in order to make 18-MEA bind tightly to the alkaline-color-treated weathered hair surface. One was to apply 18-MEA as an acid form and the other was to apply 18-MEA as a salt or complex. It was found that the combination of 18-MEA with specific cationic surfactants [stearoxypropyldimethylamine (SPDA) and docosyldimethylamine (DSDA)] makes the alkaline-color-treated weathered hair surface hydrophobic and that its hydrophobicity is maintained even after shampooing. Characterization of adsorbed layers of 18-MEA/SPDA on a mica surface, as a possible hydrophilic surface model, was performed using atomic force microscopy (AFM) and angle-resolved X-ray photoelectron spectroscopy (AR-XPS). The results revealed that 18-MEA/SPDA formed a layer with high wear resistance, with an alkyl chain, the hydrophobic moiety, oriented at an angle of around 25 degrees to the air interface.
Tanamachi
Hiroto
H
Beauty Research Center, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan.
Inoue
Shigeto
S
Tanji
Noriyuki
N
Tsujimura
Hisashi
H
Oguri
Masashi
M
Ishita
Mio
M
Tokunaga
Shinichi
S
Sazanami
Fumiko
F
D000328:Adult; D000468:Alkalies / Q000008:administration & dosage*; D004537:Eicosanoic Acids / Q000008:administration & dosage*; D005260:Female; D006197:Hair / Q000737:chemistry*; D006203:Hair Preparations; D006801:Humans; D018625:Microscopy, Atomic Force; D013499:Surface Properties
D000468:Alkalies; D004537:Eicosanoic Acids; D006203:Hair Preparations; C111345:18-methyleicosanoic acid