PROBLEM TO BE SOLVED: To provide an antibacterial agent composition that inhibits proliferation of bacteria, especially gram-negative bacteria such as Escherichia coil, Pseudomonas aeruginosa and the like in an aqueous product and an aqueous raw material in a cosmetic field, an industrial field, a medical field, an agrochemical field and the like and further in a cooling water in a cooling tower, a cooling water for air conditioning and an industrial circulation water used in a papermaking process of a paper manufacturing industry and the like.SOLUTION: An antibacterial agent composition contains a zink salt or a copper salt and a rare earth salt. Particularly, the use of an antibacterial agent composition containing a hydroxy acid salt of zinc or copper and a rare earth salt such as a salt of lanthanum, cerium, gadolinium, ytterbium or the like can inhibit proliferation of bacteria, especially gram-negative bacteria such as Escherichia coil, Pseudomonas aeruginosa and the like in an aqueous product and an aqueous raw material in a cosmetic field, an industrial field, a medical field, an agrochemical field and the like, and in a circulation water for industrial use.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】化粧品分野、工業用分野、医療用分野、農薬分野等の水性の製品や水性の原料、さらにはクーリングタワーの冷却水、空調用の冷却水、製紙工業の抄紙工程等に使用される工業用の循環水において細菌、特に大腸菌や緑膿菌等のグラム陰性菌の繁殖を抑制する抗菌剤組成物を提供することを目的とする。【解決手段】 亜鉛塩または銅塩と、希土類塩を含有する抗菌剤組成物であって、特に亜鉛または銅のヒドロキシ酸塩と、ランタン、セリウム、ガドリニウム、イッテルビウム等の希土類塩を含有する抗菌剤組成物を用いることによって、化粧品分野、工業用分野、医療用分野、農薬分野等の水性製品や水性の原料、工業用に使用される循環水において、細菌、特に大腸菌や緑膿菌等のグラム陰性菌の繁殖を抑制することができる【選択図】なし
