ANTI-BACTERIAL FIBER

To provide an anti-bacterial fiber excellent in washing durability, that has minimal effect on the human body such as skin irritation, and, in addition, that does not cause deterioration in consumption performance such as color fading over time.SOLUTION: Provided is a fiber obtained by graft polymerizing a polar vinyl monomer to a fiber, and in which the absorbance ratio B/A of the absorbance B of the absorption peak derived from alkali metal carboxylate to the absorbance A of the absorption peak derived from carboxylic acid according to infrared spectroscopy is 0.01 to 0.04, and in which, in an antibacterial evaluation using Staphylococcus aureus (yellow grape-shaped micrococcus) NBRC 12732 strain as a test strain based on a bacterial liquid absorption method and a pour plate culture method described in JIS L 1902 (2015), the antibacterial activity values of an unwashed treatment and a 10 times washed treatment in accordance with the washing method C4M of Annex F of JIS L 1930 (2014) are 2.2 to 6.5 in all cases.SELECTED DRAWING: None 【課題】 皮膚刺激等、人体に及ぼす影響が少なく、尚且つ経時変退色などの消費性能低下が生じることのない、洗濯耐久性に優れた抗菌繊維を提供する。【解決手段】 極性ビニルモノマーを繊維にグラフト重合させた繊維であって、赤外分光分析法による、カルボン酸に由来する吸収ピークの吸光度Ａに対するカルボン酸アルカリ金属塩に由来する吸収ピークの吸光度Ｂの吸光度比Ｂ／Ａが０．０１〜０．０４であること、及びＪＩＳ Ｌ １９０２（２０１５）に記載される菌液吸収法、混釈平板培養法に基づき、試験菌株としてスタフィロコッカス・アウレウス（黄色ぶどう球菌）ＮＢＲＣ１２７３２株を使用した抗菌性評価において、未洗濯、及びＪＩＳ Ｌ １９３０（２０１４）付属書Ｆの洗濯方法Ｃ４Ｍに準じ１０回洗濯処理した後の抗菌活性値がいずれも２．２〜６．５である。【選択図】なし