The object of the Disclosed solubility vitreous antimicrobial agent when used as a water treatment applications, while preventing the discoloration and disintegration properties, with sufficient antimicrobial effect and excellent filling workability It is to provide a water treatment agent for the particulate. 0-5% of SiO 2, at a mass ratio of [resolution] means in terms of oxide, 5-10% is 2 O K, 0.1~5% is 2 O Ag, 60~75% is B 2 O 3, Al 10-20% is 2 O 3, disintegrating small above having a high antibacterial solubility vitreous antimicrobial agent one or more contain 0-10% of at least selected from the group consisting of MgO, BaO, from ZnO , I found that the discoloration is also small. In addition, the water-permeable and filling property are both excellent, they have found that is highly useful as a water treatment agent, which was molded into particles having a bulge on at least one side of the solubility vitreous antimicrobial agent, and completed the invention .【課題】 本発明の課題は、水処理用途として使用する際に、崩壊性及び変色性を抑制しつつ、十分な抗菌効果を備えた溶解性ガラス質抗菌剤、および、充填加工性にも優れた粒状の水処理剤を提供することである。【解決手段】 酸化物換算の質量比でSiO2が0~5%、K2Oが5~10%、Ag2Oが0.1~5%、B2O3が60~75%、Al2O3が10~20%、MgO、BaO、ZnOからなる群から選ばれる少なくとも1種以上が0~10%を含有する溶解性ガラス質抗菌剤は高い抗菌性能を有する上に崩壊性が小さく、変色性も小さいことを見出した。また、当該溶解性ガラス質抗菌剤を少なくとも片面に膨らみを有する粒状に成型したものは、充填性と通水性が共に優れており、水処理剤として有用性が高いことを見出し、発明を完成した。
