A process for tanning hides for soles or insoles with ammonium titanyl sulphate. The hides, subjected to soaking, liming, fleshing and deliming, are first treated with ammonium sulphate. Successively, ammonium titanyl sulphate as well as citric acid or an alkali metal citrate are gradually added to the bath, while maintaining the bath temperature at a value not exceeding 37 ° C and the bath pH at from 1.7 to 2.5. After each addition, the hides are treated until they have absorbed at least 90% of the soluble Ti (IV). Sodium sulphite and hexamethylenetetramine are then gradually added; this addition is such as to bring the final pH of the bath to 3.8 - 4.5 and to exhaust the bath of soluble Ti (IV). NaHC03 is then added until a pH value of the bath from 4.9 to 5.0 is reached, such pH being maintained for at least 2 hours. At least one tanning treatment with a tannin, either prior to the treatment with ammonium titanyl sulphate (pretanning), or after the treatment with NaHC03 (additional tanning) is carried out, such tanning being carried out with a synthetic or vegetable tannin in the former case, and with a synthetic tannin and/or rubber-like polymer in the latter case.
一种用
硫酸钛酸
铵鞣制鞋底或鞋垫用皮革的工艺。首先用
硫酸铵处理经过浸泡、浸灰、去皮和划线的皮革。随后,
硫酸钛酸
铵和
柠檬酸或碱
金属
柠檬酸盐被逐渐加入浴槽中,同时保持浴槽温度不超过 37 °C,浴槽 pH 值在 1.7 至 2.5 之间。每次添加后,都要对皮革进行处理,直到它们吸收了至少 90% 的可溶性 Ti (IV)。然后逐渐加入
亚硫酸钠和
六亚甲基四胺;加入的方式是使熔池的最终 pH 值达到 3.8 - 4.5,并使熔池中的可溶性 Ti (IV) 全部耗尽。然后加入 NaHC03,直到浴液的 pH 值达到 4.9 至 5.0,这样的 pH 值至少要保持 2 个小时。在用
硫酸钛酸
铵处理之前(预鞣)或在用 NaHC03 处理之后(附加鞣制),至少用
单宁酸进行一次鞣制处理,前者用合成
单宁酸或植物
单宁酸进行鞣制,后者用合成
单宁酸和/或橡胶类聚合物进行鞣制。