| 摘要 |
<p>Bayer 3498-LH:rw CHROME-TANNING In the chrome-tanning of animal skins and hides by pretanning the pickled pelts with chromium (III) salts, followed by full tanning with chromium (III) salts and acid-binding agents, the improvement which comprises effecting full tanning with the reaction product at least one of formic acid and a formate with a basic chromium (III) sulphate, at least 2 moles of formate plus formic acid being used per mole of Cr2O3 in the chrome-tanning agent used for full tanning, the total input of chromium oxide being from about 1.0 to 1. 8%, based on the weight of the pelts, and tanning being carried out with a liquor volume of at most 100.degree.%, based on the weight of the pelts, up to a final pH-value of at least 4.0.</p> |
