| 摘要 |
PURPOSE: To obtain a crystalline antimicrobial composition excellent in heat resistance and weatherability (light resistance), with the matrix predominant in gahnite crystal structure, containing metal ions such as silver ions, and having each specified specific surface area and bulk specific gravity. CONSTITUTION: Firstly, antimicrobial zeolite is prepared by partially or fully substituting mainly silver ions or silver ions plus at least one kind of metal ions selected from zinc and copper ions for the ion-exchangeable cations in zeolite. Second, the antimicrobial zeolite is heat-treated within such a temperature range as to be higher than the temperature to induce crystal phase transition thereof and the crystal structure of the antimicrobial zeolite is deteriorated or destroyed, and finally, the objective composition, antimicrobial fine crystal powder freed from zeolite characteristics consisting mainly of alumina and silica, is obtained. This composition has a bulk specific gravity of 0.8-1.4 and 5-300m<2> /g in specific surface area. As the additional metal ions, there may be at least one kind selected from divalent nickel ions, divalent zirconyl ions and trivalent rare earth metal ions. |
