| 摘要 |
White cellulosic textile materials of the class used for the manufacture of articles requiring frequent laundering are rinsed, in the form of piece goods, yarn or fibre, in an aqueous bath containing a very small proportion of a substantive blue-fluorescent substance. Advantageously the aqueous bath contains not more than 0.05 per cent and suitably between 0.01 per cent and 0.001 per cent of the blue-fluorescent substance calculated on the weight of the textile material to be treated. Specified substances are: a di-benzoylaminostilbene sulphonic acid or a nuclear substitution derivative thereof or a salt of these acids, e.g. a 4 : 41-dibenzoylaminostilbene-2 : 21-disulphonic acid or a nuclear substitution derivative thereof or a salt of these acids, 4 : 41-di-p-aminobenzoylaminostilbene-2 : 21-disulphonic acid or a salt thereof, sodium 4 : 41 - di - p - methylbenzoyl - aminostilbene - 2 : 21 - disulphonate; the corresponding 3 : 31-disulphonates and 2 : 21-6 : 61-disulphonates; the symmetrical urea derived from sodium 4-amino-41-benzoylaminostilbene-2 : 21-disulphonate; dibenzyl derivatives such as sodium 4 : 41-dibenzoylaminobenzyl-2 : 21-disulphonate; benzidene derivatives such as sodium dibenzoylbenzidine-3 : 31-dicarboxylate. In an example a new white cotton cloth is rinsed for a few minutes in an aqueous bath containing 0.005 per cent (calculated on the weight of the cloth) of the sodium salt of 4 : 41-di - p - aminobenzoylaminostilbene - 2 : 21 - disulphonic acids. Specifications 442,530, [Group VIII], and 522,672 are referred to. |
