Abstract
A complex-forming quality of condensed phosphates with calcium ion and their effects on raw silk when treated with hard-water were investigated, The procedures are the same as reported previously. The results were as follows:
(1) The order of the softening ability of condensed phosphates for hard-water is sodium meta phosphate glass (so-called hexameta phosphate)>sodium triphosphate>sodium pyrophosphate.
(2) The dissolving power of water, soap and silicate for sericin is decreased as the hardness of the solvent is increased respectively.
(3) The complex-forming quality of condensed phosphates for all metallic ions is enabled to remove the contaminations of metallic soaps easily, therefore, the mixture of soap and condensed phosphates is better than the other degumming agents for raw silk when the hardness of the solvent is high.
