| 摘要 |
<p>586,540. Degreasing hides and skins. BURCHILL, J., COCKBAIN, E. G., McLAREN, K., PARRY, E. G., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Dec. 11, 1944, No. 24769. [Class 76] Hides and skins are degreased either before or after tanning by treatment with an aqueous liquor containing an emulsifying agent obtained by condensing an alkyl phenol having a straight chain or branched alkyl group of from six to twelve carbon atoms or two or more alkyl groups of four or five carbon atoms, with at least five and not more than twenty molecular proportions of ethylene oxide, for example as described in Specifications 380,431 and 470,181, [Group IV]. Suitable emulsifying agents may be formed from p-octyl phenol and 7-9 molecular proportions of ethylene oxide, from a mixture of p-(di-iso-butyl) phenol and 2:4 di-tert-butyl phenol with eight molecular proportions of ethylene oxide, from an octylated mixture of cresols and 9-11 molecular proportions of ethylene oxide, and from a dodecylated mixture of cresols and 12-14 molecular proportions of ethylene oxide. The weight of liquor used is preferably not more than 200 per cent. of the weight of the skins, and the proportion of emulsifying agent may be 1-5 to 5 per cent. based on the weight of the skins. Treatment before tanning may be carried out at 25-35‹C. and the liquor may include an inorganic salt, such as sodium chloride, sodium sulphate, or potassium chloride, to depress swelling. In the treatment of tanned skins temperature up to 60‹C. may be used, and the liquor may contain formic, acetic, or sulphuric acid to reduce the loss of tanning material. Octyl alcohol, pine oil, or Turkey Red Oil may be added to the liquor as foam depressants. Treatment may be effected in a rotating drum, the skins then being washed with water which may contain the additives referred to above.</p> |
