Tanning compsns - contg reaction product of dialdehyde and formaldehyde to prevent yellowing

摘要

W,W'-dialdehyde (s) contg. 2-8C atoms (pref. glutardialdehyde or glyoxal) is reacted with formaldehyde in soln. in a molar ratio of 1-4 to 1:6. The resulting prod. can be used in tanning or after-tanning baths. Yellowing of the leather occuring when a dialdehyde is used alone is prevented. Excellent hand, whiteness and resistance against shrinkage and tearing are achieved.