Lignosulfonate application in leather tanning

Lignosulfonate directly used in leather tanning effect is not good. Chemically modified lignosulfonate has a suitable distribution of the particle radius and bring a better soluble collagen protein reactive with a functional group reactive groups, can be used for leather tanning or retanning.

Suitable modified lignosulfonate (re) tanning agent processed into leather performance to meet the market demand, and help to reduce chromium ion in tannery wastewater pollution of the environment.

A major modification of methods are: lignin sulfonic acid and phenol, formaldehyde condensates; lignin sulfonic acid and dimethylol urea – phenol sulphonic acid condensate; lignin sulfonic acid and 4,4 ‘- dihydroxydiphenyl sulfone condensation; wood Su acid with dicyandiamide, formaldehyde condensates.

Lignosulfonate and aluminum or chromium salt of chromium compound is formed after the sulfonated phenol-formaldehyde condensation. Lignin sulfonic acid resin can also be used to improve the product spray-dried power and dispersion.