The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 24, 1985
Filed:
Jun. 07, 1984
Sergio Vanni, S.Croce Sull'Arno, IT;
Loris Guidi, S.Croce Sull'Arno, Pisa, IT;
Paolo Vallini, San Miniato, IT;
Renato C Pace, Alessandria, IT;
Carlo Scotti, Voghera, IT;
Other;
Sibit S.p.A., Milan, IT;
Abstract
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 temperature of the bath at a value not exceeding 37.degree. C. and a pH at values ranging 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 in soluble Ti (IV). NaHCO.sub.3 is successively added until a pH value of the bath ranging from 4.0 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 NaHCO.sub.3 (additional tanning), is carried out, said tanning being accomplished with a synthetic or vegetable tannin in the former case, and with a synthetic tannin in the latter case.