| 摘要 |
An aqueous composition for finishing or colouring leather comprises an emulsified oil, fat, or wax, a condensation product of a soluble protein or protein degradation product with a higher fatty acid, resinic or naphthenic acid, or a higher aliphatic or aliphatic-aromatic sulphonic acid, and, in the case of a colouring finish, an organic or inorganic pigment or dye. A protein such as albumin, gelatine, globulin, or casein, which may be solubilized with ammonia, may also be added. The condensation product may be obtained by reacting solutions of water- or alkali-soluble proteins such as size, gelatine, casein, albumin, globulin, or cleavage products formed by the hydrolytic decomposition of proteins such as protalbic or lysalbic acid with a halide of the selected carboxylic ar sulphonic acid in the presence of acid binding media. Suitable acids are dodecyl benzene sulphonic acid, or fatty acids having straight or branched hydrocarbon chains of 10-20 carbon atoms, e.g. soya or peanut oil fatty acids. The oil, wax &c., which may be neat's foot oil or Japan wax, may be emulsified with the aid of the protein-acid condensation product; or the neat's foot oil may be lightly sulphonated. Blood, albumin, and shellac may also be added. The finish may be fixed by treatment with formaldehyde or chromium salts. A coloured coating may be followed by a glazing layer of similar composition from which the pigments are omitted. |
