ON THE DIBASIC ACIDS IN JAPAN WAX

Abstract (1) As “japanic acid” of Geitel and van der Want appears not the only dibasic acid in Japan wax, this name has been reserved for a while, and the expression of the “Japan wax dibasic acids” or more simply the “dibasic acids” is used in this paper. (2) Basing on the difficult solubility of the dibasic acids in petroleum ether, a method for their approximate determination has been proposed. The results obtained by this method show that the content of the dibasic acids in the mixed fatty acids of Japan wax amounts to 5–6%, which are far greater than hitherto considered. (3) For the preparative separation of the dibasic acids, the lead salt precipitation method and the ester distillation method have been found to be most convenient. (4) As the results of the chemical examination of the dibasic acids, it has been concluded that the main constituent of the acids is heneicosane dicarboxylic acid, C23H44O4, but probably eicosane dicarboxylic acid, C22H42O4 also occurs in a fair proportion. (5) As a peculiar property of the dibasic acids, it has been found that the comparatively small addition of them to fatty and waxy substances makes the crystalline structure of these substances finer and more opaque, and at the same time gives certain coherency and tenacity. (6) The characteristic property of Japan wax that it may be kneaded to a “mochi”-like mass without adhering to the fingers is due to the presence of the glycerides of the dibasic acids.