Chrome tanning process
US10844445B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2014 |
| Grant date | Nov 24, 2020 |
| Priority date | — |
| Expiry date | Sep 30, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC14C1/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention concerns a process for tanning hide to obtain leather. The general process for obtaining the intermediary wet blue stage comprises the following steps: a) a picking step with acid and salt, followed by b) a tanning step with chromium salt, followed by c) a basification step. The invention is characterized in that between step b) and c), a re-acidification step with organic acids is added. In particular the organic acids are selected from glutaric acid (GA), 2-methyl glutaric acid (MGA), succinic acid, ethyl succinic acid (ESA), adipic acid (AA), maleic anhydride, fumaric anhydride, tricarboxylic acids, hydroxycarboxylic acids, and mixture thereof. This invention enables an increase of the up-taking of the re-tanning products and provides leather with improved mechanical properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.