抄録
Anti-microbial materials were synthesized with silver thiosulf ato complex Rp[Agq(S2O3)r](R=Na, K) on silica gel. Thermal stability of the materials was better with a potassium salt than a sodium salt. It was suggested that the change of cation “R” of the complexes from Sodium to Potassium resulted in thermal stability against oxidation after decomposition of the complexes. Among several cations for the complex, potassium was the most suitable. Potassium salts of the complex Kp[Agq(S2O3)r] were synthesized with various ratios of r/q from 1 to 8. With various ratios of r/q, each sodium or potassium salt of the complex was kneaded with resin, and the color difference value ΔE of the surface against natural resin was measured. TG-DTA measurements showed minimum thermal stability at r/q=4 and maximum at 6. Color measurements showed lower ΔE values with K salts than Na salts. The ΔE values of both salts showed peaked at r/q=4 and decreased at 6. Results of thermal stability TG-DTA measurements showed an agreement with the result of color measurements. It was thus suggested that the complex of potassium salt with an S2O3/Ag ratio of “6” had superior properties among the complexes for thermal stability against kneading treatment with resin. The chemical composition of the complex was K11[Ag(S2O3)6].
