Isothiazolinone as a fungicide for leather and shoe lining

Wet-blue pieces were treated with isothiazolinone at different concentrations in a drum and then the treated pieces were washed. During the treating and washing, the absorptivity and wash-out rate of isothiazolinone from the wet-blue were tested by UV/VIS spectrophotometry. The results showed that the highest absorptivity was about 45% in 15 minutes and the wash-out rate reached nearly 55% after washing for only 15 minutes. Thus, when applied to wet-blue, isothiazolinone should be added at the later stage of chrome tanning and the wet-blue preserved without further washing because of its poor washability. To investigate the distribution of isothiazolinone, the wet-blue pieces treated with 0.25% isothiazolinone (solution concentration) were split into three layers and the inhibition zones of each layer against two fungi were measured. The inhibitory effects of the split layers were also determined by inoculating fungal spores on the wetblue discs with and without culture medium. The results showed that the standard deviations of diameters of inhibition zones among the three layers were low at close to 2mm, indicating that isothiazolinone is distributed uniformly in wet-blue. The finished leather and the shoe lining were also treated with different concentrations of isothiazolinone. The inhibitory effects of treated lining and finished leather were evaluated by inoculating fungal spores on sample discs with a culture medium. Evaluation of the finished leather coated with 135.95mg/m2isothiazolinone and the lining (with 77.16mg/g)isothiazolinone inhibited the growth of 8 different fungi for 60 days. The above results may contribute to the application of isothiazolinone to the leather industry.