| Name | synthetic tanning agent HV |
| Synonyms | synthetic tanning agent HV |
| PH | 2.4~3 |
| Storage Condition | 置于阴凉库内，5~30℃条件下，贮存期12个月。本品按非危险品存贮。运输时应防止曝晒、雨淋。 |
| Physical and Chemical Properties | Chemical properties brown viscous liquid. Soluble in water. It has good tanning. Helps dissolve the glue. |
| Use | With the use of domestic tannin, tanned a variety of sheep clip leather, Pig clip leather, bag leather. Leather light color, soft, light, can be dyed into a variety of colors. Should be stored in a cool, dry place. |
| 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. |
1. Add 400 parts of phenol to the reactor and heat to melt. Then add 465 parts of 98% concentrated sulfuric acid dropwise, control the temperature between 90~100 ℃ during the dropwise process, and stir at around 110 ℃ for 2 hours to obtain p-hydroxybenzenesulfonic acid.
2. Transfer p-hydroxybenzenesulfonic acid into a sulfonation reactor, raise the temperature to 145-150 ℃, and hold for 4 hours to obtain 4,4 '- dihydroxydiphenylsulfone. Add ethylnaphthol to the reactor, heat and melt it, and then add 985 parts of concentrated sulfuric acid dropwise to undergo sulfonation reaction at around 80 ℃ to obtain hydroxynaphthalene sulfonic acid.
3. Mix hydroxynaphthalene sulfonic acid with 4,4 '- dihydroxydiphenylsulfone and add it to a reactor. Then, add urea and 37% formaldehyde aqueous solution for condensation reaction to obtain the product.