Abstract
The decreased preservative effect by tale and $TiO_2$ for emulsions obtained with polyoxyethylene surfactant was studied by various analytical methods and biological test. The preservative effect of methyl p-hydroxybenzoate was decreased by the addition of talc and $TiO_2$ and this result was attributed to the adsorption of methyl p-hydroxybenzoate on them. Talc exhibited more decreased preservative effect than that of $TiO_2$. The amount of the adsorption of methyl p-phydroxybenzoate by talc at $20^{\circ}C$ could be represented by the following equation; $a=11.511C^{0.747}$.
Polyoxyethylene계 유화제를 이용한 유화계에 있어서 talc 및 $TiO_2$에 의한 methyl p-hydroxy benzoate의 흡착과 그에 따른 방부력 감소를 여러 가지 분석방법과 미생물 실험을 통하여 측정하였다. 이 유화계에 있어서 methyl p-hydroxy benzoate는 talc 및 $TiO_2$에 흡착되어 방부력이 감소함을 알 수 있으며 방부력 저하에 미치는 영향은 $TiO_2$보다 talc가 더 크고, talc에 의한 methyl p-hydroxy benzoate의 흡착량은 $20^{\circ}C$에서 다음과 같은 식으로 나타낼 수 있었다. 즉 $a=11.511C^{0.747}$