Aqueous composition for the pretanning of hide pelts or retanning of leather
AssigneeCiba Specialty Chemicals Corporation
InventorAlain Lauton
Life of this patent
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Abstract
An aqueous composition for the pretanning of hide pelts or for the retanning of leather comprises (A) an aliphatic dialdehyde containing 2 to 8 carbon atoms, (B) an anionic aromatic tanning agent, (C) water and, if desired, (D) an acid. The leather tanned or pretanned with this aqueous composition exhibits a good degree of whiteness and has a high shrinkage temperature.
Claims16
An aqueous composition for the pretanning of a pickled hide pelt or retanning of leather, which consists essentially of
- (A) an aliphatic dialdehyde containing 2 to 8 carbon atoms,
- (B) an anionic aromatic tanning agent,
- (C) water and, optionally,
- (D) an acid,
- wherein said composition contains from 1 to 30% by weight of component (A) and from 10 to 75% by weight of component (B).
A process for the pretanning of a pickled hide pelt or for the retanning of leather, which comprises treating a pickled hide pelt or a pretanned leather in an aqueous liquor consisting essentially of
- (A) an aliphatic dialdehyde containing 2 to 8 carbon atoms,
- (B) an anionic aromatic tanning agent,
- (C) water and, optionally,
- (D) an acid, wherein said aqueous liquor contains from 1 to 30% by weight of component (A) and from 10 to
- 75% by weight of component (B).
An aqueous composition for the pretanning of a pickled hide pelt or retanning of leather, which consists essentially of
- (A) an aliphatic dialdehyde containing 2 to 8 carbon atoms,
- (B) an anionic aromatic tanning agent,
- (C) water and, optionally,
- (D) an acid,
- wherein said composition contains from 2 to 20% by weight of component (A), from 20 to 55% by weight of component (B), sufficient acid to establish a pH of between 1 and 6.5, and water to make up to 100% by weight.
A process for the pretanning of a pickled hide pelt or for the retanning of leather which comprises treating the hide pelt or leather with from 1 to 10% by weight, based on the weight of the leather or of the hide pelt, of an aqueous composition which consists essentially of
- from 1 to 30% by weight of an aliphatic dialdehyde containing 2 to 8 carbon atoms,
- from 10 to 75% by weight of an anionic aromatic tanning agent, sufficient acid to establish a pH of between 0.5 and 6.8, and water to make up to 100% by weight.
Dependencies are inferred from the claim text.