1964 年 13 巻 12 号 p. 656-661
The solubilizing activity and detergency of some kinds of sodium dodecylbenzenesulfonates have been determined.
In case of solubilizing Orange-OT at 25°C, linear type dodecylbenzenesulfonates are superior than tetramer types, except n-dodecylbenzenesulfonate restricted by its poor solubility.
In hard water, the solubilizing activity of the sulf onates of both types goes through a maximum at an appropriate hardness range, and then at severe hardness level the solubilizing activity is decreased almost to zero. By the addition of sodium sulfate, their solubilizing activities are increased, and by the substitution of a part of the sulfate with sodium tripolyphosphate the range of maxima is moved to higher hardness regions.
In case of dodecyl-6-benzenesulfonate which clearly shows the shift phenomenon, it was found that maxima exist at a range of calcium/tripolyphosphate equivalent ratio of 0.60.7, without any relations to the concentrations of the sulf ovate and phosphate.
The detergency, which was determined by soiled glass plate method at 25°C, is also enhanced at appropriate hardness ranges, and by the addition of the phosphate, the enhanced range of the detergency moves toward higher hardness level, or the detergency is not decreased untill higher hardness level.