| 摘要 |
Performic acid in aqueous solution, obtained by reacting hydrogen peroxide with at least one substance yielding formaldehyde, a low molecular weight formic ester, or a low molecular medium, is used as a bleach bath. Substances yielding formaldehyde have at least one group of formula Y-CH2-X where Y is nitrogen or oxygen, X is nitrogen or oxygen or a -SO3M group where M is a proton, ammonium ion, an alkali metal ion or half an alkaline earth metal ion. Examples are given and include formaldehyde polymers, formals, hydroxymethane sulphonic acid, amino methane sulponic acid and others. Low molecular weight formic esters and formamide have the general formula <FORM:1064534/C2/1> in which Q is a radical -OR or <FORM:1064534/C2/2> R being alkyl (1-5 C), R1 and R2 hydrogen atoms or alkyl groups (1-5 C), e.g. methylbutyl formates, and diethyl formamide. Additional components which prevent a drop in pH value during the bleaching may be hexamethylene tetramine, formamide, dimethyl formamide, aminomethanesulphonic acid, iminobismethanesulphonic acid and their alkyl derivatives and salts.ALSO:Bleach liquor for synthetic or natural protein fibres containing performic acid is prepared by reacting hydrogen peroxide with at least one substance yielding formaldehyde, a low molecular weight formic ester, or a low molecular weight formamide in an acid or neutral aqueous medium (see Division C2), and if desired the solution may be diluted and adjusted to a pH of 1 to 8.5 formaldehyde polymers; hydroxymethane-sulphonic acid and its sodium, potassium, and calcium salts; the reaction products of this acid with ammonia, and hexamethylene tetramine are the preferred reactants with hydrogen peroxide. Stabilisers for the active oxygen such as alkali metal polyphosphates; magnesium silicate; magnesium phosphate; and complex-forming amino-polycarboxylic acids may be present together with wetting agents, detergents and/or softening agents and optical brighteners. Simultaneous bleaching and dyeing of proteinaceous fibrous material may be carried out at elevated temperatures using the bleach solutions above containing 0.2 to 10 gm./litre of active oxygen and wool dyes which are resistant to oxygen such as acid azo, acid anthraquinone, 1:1 metal complex and 1:2 metal complex dyes. Conventional assistants such as levelling and wetting agents, carriers, dispensing agents, buffer salts, neutral salts and fibre protectives may also be present. A brightening or antifelt finishing by chlorine, may also be carried out in the same liquor. Many examples describe the use of the liquor in winch, cheese, pack, tops or cross-wound bobbin, and suspension dyeing machines to process wool-polyacrylonitrile, wool-rayon, wool, wool-polyster, nylon, pig-bristles and feathers. |
