... Tanning Chemicals 1.insoluble:0.05%max 2.PH value:7-9 3.content of calcium and magnesium:4000PPM max Leather ... product),%95Sodium sulfate content,%18-5PH value(1% water-solution)7--9Insolubles in water,%≤0.05Content of calcium and magnesium ion ... preferable.7) As dispersant in leather and rubber industry. Can disperse sulfur,accelerant, anti-aging agent and some filler(like zinc oxide,barium ...