Abstract
Effects of antibacterial agent on the antibacterial properties of polypropylene (PP) plates were examined quantitatively under the aspect of actual use. Silver-ion supported by zeolite (AgZL) was used as the antibacterial agent. The PP specimens containing AgZL were prepared by the injection molding method. The antibacterial property of the specimens was evaluated by using used bath water as a test bacteria body. Secretion liquids from the human body such as urine, saliva and sweat were also used for the test bacteria bodies by using artificial liquids. The following appeared from the experimental results. The antibacterial activity value of the specimen containing 0.5 wt% of AgZL was greater than 2 for the contact time of 12 h of used bath water. The antibacterial activity value decreased with increased contact time for the artificial sweat and urine. In particular, the decreased rate was larger for the artificial urine. However, the antibacterial activity value was almost constant against the contact time in the case of artificial saliva. It is concluded that the antibacterial property depends largely on the sodium chloride concentration in the secretion liquid because of the elusion effect of sodium chloride on the silver-ion in AgZL.
