| 摘要 |
A composition, suitable for use as a tanning agent in the preparation of leather, comprising a mixture of aluminium sulphate and a magnesium salt. The composition may also contain a titanium salt, optionally stabilised with a complexing agent, especially a poly(hydroxy)aliphatic-carboxylic acid. The composition may also contain or be used in conjunction with conventional mineral or vegetable tanning agents, such as chromium or zirconium salts. It may also be used with or contain an internal basifying agent, for control of pH during the tanning process, such as calcium carbonate or dolomite. The tanning agents may be used for the prepraation of pre-tanned ("wet-white" or "dry-white") or fully tanned leathers, especially in conjunction with small quantities of chrome tanning agents, and produce leathers having generally superior properties to conventionally tanned leathers. The invention also includes pre-tanning, tanning and re-tanning processes using the new tanning compositions and pre-tanned, tanned and re-tanned leathers arising from these processes. |
