| PH | 10~11 |
| Physical and Chemical Properties | The appearance is red-brown liquid, easily soluble in water, and has good permeability. It can fix the combination of tannin and skin collagen and improve the tanning coefficient. Easy polycondensation under acidic conditions. |
| Use | Fixed tannin extract. It can endow leather with excellent softness and uniform filling. The pH value should not be too low during use to avoid condensation. |
| Caution | Irritating, pay attention to protection. Wash immediately with soap and water if it gets on the skin. Do not come into contact with iron products. Under the condition of 5-30 ℃, the storage period is |
Phenol undergoes sulfonation methylation with formaldehyde and sodium bisulfite to obtain the sulfonation product of phenol. Then, urea is condensed with formaldehyde and furfural to obtain the condensation product, and the two are mixed proportionally to obtain the product.