| PH | 3.5 |
| Storage Condition | 置于阴凉、干燥的库房内，防止日晒、雨淋。保质期12个月。 |
| Physical and Chemical Properties | The chemical product is a brown liquid. It has complexation with chromium salt, which can make the complex tanning leather have a good whitening effect, and has good light resistance and filling. |
| Use | Used for soft leather retanning, especially suitable for the retanning of chrome tanned leather to produce white leather. |
| Caution | It has absorption and contact toxicity. When using, gloves and protective glasses should be worn to avoid direct contact with the skin and eyes. If it gets on the skin, rinse with water and soap. |
Add 750kg of phenol to the reactor, add 18kg of sulfuric acid, heat to 70-80 ℃ under stirring, and then add 480kg of formaldehyde aqueous solution (37%) and stir for 30 minutes. Add 500kg of water, 700kg of crystalline sodium sulfite, and 230kg of formaldehyde aqueous solution (37%), and stir for 30 minutes. Add 2% sulfuric acid aqueous solution to adjust the pH value, heat and boil until transparent, and the reaction ends. Then adjust the pH value to 4~4.5, add 70kg urea, 50kg formaldehyde (37%), 150kg aluminum sulfate and react at 60 ℃ for 1h to obtain the product.