| 摘要 |
<p>Leather or skin is made water-resistant by impregnating it with a solution, in an organic solvent, of partly esterified or partly amidated citric acid containing in the molecule at least one free carboxyl group and an unsaturated hydrocarbon residue of high molecular weight. Suitable citric acid derivatives are: monooleyl citrate, dioleyl citrate, citric acid monooleylamide and the monoundecenyl ether of monooleyl citrate. The solution may also contain: an alcoholate of a polyvalent metal (e.g. aluminium, magnesium, titanium or zirconium) and an acid derivative of high molecular weight of phosphoric acid; a condensation product formed from these two substances; a silicone oil; a hard natural or p synthetic wax; or a small amount of mineral oil. The Specification also describes by way of comparison the treatment of leather with a solution containing a condensation product of aluminium isopropylate and dodecylphosphoric acid, montan wax and silicone oil but no citric acid derivative. Specifications 826,025 and 876,653 are referred to.</p> |
