Cotton fabrics bleached using ozone micro bubbles were examined. Since the solubility of ozone in water improves in acid, the effect of adding an acid (acetic acid) to water, and the effect of adding an electrolyte (NaCl) to stabilize micro-bubbles were investigated; a low temperature and pH 6 with 45 g of electrolyte gave the best conditions, and 1 hour of bleaching a cotton fabric gave a whiteness of more than 85. The scale of the experiment was expanded based on these processing conditions, a 2.2 kW micro-bubble generator was used, and 1 kg of cotton fabric was processed. The same whiteness of more than 85 was achieved from 1 hour of ozone micro-bubble processing, just like the previous experiment. The ozone concentration at this time was about 11 mg/L, a high concentration. Degradation of the cotton fabric due to ozone oxidization was investigated, and tensile strength was found to be comparable to the original fabric, and no degradation due to the bleaching processing was seen. However, since a merit of using ozone is expected to be an antibacterial effect, we used coliform bacillus in an examination and after the ozone micro-bubbles process was implemented, none of the bacteria could be detected.

References
(１) 中瀬一博，大島邦裕：「獣毛の改質方法」，特開2001-164460.
(２) 市村　恒，梅原　亮：「防縮性に優れた獣毛繊維およびその製造方法」，特開2002-105851.
(３) 小林孝之，浅野春香，山本周治：「オゾンマイクロバブルによる綿繊維の新規漂白法」，繊維機械学会誌，Vol.63，No.7，pp.374-377 (2010)．

Questionnaire 2014/Shinshu University Faculty of Textile Science and Technology Fii