Abstract
In order to sterilize wash water and impart an antibacterial property to a fabric after washing, metalion-supporting zeolites (silver, copper and zinc) were evaluated for their water softening abilities. The water softening effect on mineral ions in water was then examined, and washing was carried out with metal-ion-supporting zeolites. In addition, the sterilizing effect in the aqueous solution was evaluated. While the metal-ion-supporting zeolites had lower calcium-ion exchange abilities than non-metal-ion supporting zeolites, 0.50 wt% of these metal-ion supporting zeolites yielded a sufficient calcium-ion trapping effect. Furthermore, the calcium-ion trapping effect was sufficient after about 5 min of stirring. Artificially soiled cotton fabrics were washed with 3.0 × 10-4 mol/l of sodium dodecylbenzenesulfonate (hereafter “DBS”) and 0.50 wt% of a number of zeolites. A detergent efficiency of over 30% was obtained when metal-ion-supporting zeolites were used. However, when no zeolite was added, the detergent efficiency was as low as 12. 5%. The sterilization effect of metal-ion-supporting zeolites proved that living bacteria could not be found upon addition of only 0.002 wt% of zeolites (ZL-2 to ZL-5). When 0.01 wt% of zeolite was added, the sterilization effect began to occur after 15 min, and after 30 min no living bacteria could be observed at all.
