Abstract
In this paper, the dyeing mechanisms of a few natural dyes composed of flavon skeleton for silk were examined from the dye uptake and affinity of adsorption. The results obtained are as follows: 1) Adsorption of dyes on no-mordanted silk was the Langmuir type (L-type). 2) These adsorptions were found to be exothermic reactions, because the amount of adsorption at equilibrium became smaller according to the temperature increase. 3) Adsorption isotherm of aluminium ion on silk was BET type, and was L-type from initial adsorption to equilibrium one. The amount of saturated adsorption was corresponded to the amount of carboxy-endgroup in silk. 4) Adsorption of dyes on silk mordanted with aluminium ion was also L-type. The amount of saturated adsorption was 3.1×10-4mol/g, and this value was corresponded to the summation of the amount of carboxy-endgroup and that of amino-endgroup in silk. 5) The dye uptakes were accelerated in the following order: silk mordanted with aluminium ion>silk mordanted with copper ion>no-mordanted silk. 6) In the case of Rutin the relationship between the dye uptake and pH was resembled to that in the acid dye-silk system.
