| 摘要 |
1,235,422. Dehairing hides and skins. ROHM G. m. b. H. April 14, 1969 [April 13, 1968], No.19043/69. Heading C6C. In a process for dehairing hides or skins by treatment with an enzyme product, the hides or skins are treated with a proteolytic enzyme, e.g. papain and/or pepsin, in the presence of an aqueous medium at a PH not greater than 5, the composition of the medium being such that no substantial swelling of the hides or skin occurs, this treatment being followed by treatment with an oxidizing agent, e.g. sodium chlorite. The aqueous medium is preferably in the pH range 3-5, particularly pH 4, and contains 0À1 to 0À5 per cent (calculated on the soaked weight of hides or skins) of the enzyme product which has a concentration of 55, 000 to 60, 000 Enzyme units, as measured by the activity of the enzyme with haemoglobin as substrate, measuring being effected after a 10 minute treatment by examination with a spectro-photometer and using the following formula, based on a measured extinction of 0À400: - EZA = 15, 250/ weight of sample in mg. The desired pH is obtained either by a combination of hydrochloric acid and a neutral salt, e.g. sodium chloride, by the use of naphthalene sulphonic acid, sulphophthalic acid or hydrocy - isobutyric acid, whereby substantial swelling of the hides or skins is prevented. |
