Verfahren zum optischen Aufhellen von Cellulosefasern

摘要

Cellulosic materials, e.g. cotton and linen fabrics, are brightened by impregnating them at temperatures under 100 DEG C. with an aqueous solution of a salt of at least one compound having the formula in which A1 and A2 are phenyl radicals which may be substituted by alkoxy, alkyl, carboxyl, sulphonic acid or sulphamyl groups or by halogen atoms and X1 and X2 are alkoxy groups which may be substituted, primary amino groups or secondary or tertiary amino groups having aliphatic, araliphatic, cycloaliphatic or aromatic nitrogen substituents which, together with the nitrogen atom and if desired, further hetero atoms, can also form hydrogenated heterocycles, and then steaming them, if desired after drying. X1 and X2 may be methoxy, ethoxy, butoxy, b hydroxy ethoxy, b methoxy ethoxy, b ethoxy ethoxy, b butoxy ethoxy, amino, methylamino, ethylamino, propylamino, b hydroxyethyl amino, b hydroxy propylamino, b cynoethylamino dimethylamino, diethylamino, bis-b -hydroxyethyl amino, N-methyl-N ethylamino, N methyl N-b -hydroxyethylamino, N-ethyl-N-b hydroxyethylamino, N-methyl-N-b -hydroxy-propylamino, N ethyl-N-b hydroxy-propylamino, benzylamino, N-b -hydroxyethyl-benzyl-amino, cyclohexylamino, N ethyl-cyclohexylamino, N-b -cyanoethyl-cyclo hexylamino, phenylamino, o, m or p-methyl phenylamino, 3, 5-, 2, 5- or 3, 4-dimethyl-phenylamino, m- or p-methoxylethoxy, chloro-bromosulpho-, sulphamyl- or carboxyphenylamino, 2, 5 dimethyl-4-sulphophenylamino, 4-chloro-3-carboxy phenylamino, carboxy methylamino, N-methylcarboxymethylamino, 2 methoxyethylamino, N-methyl-2-methoxyethylamino, 2 ethoxyethylamino, 3-methoxy-propylamino, piperidine or morpholino groups. The impregnating bath may also contain chemical bleaching agents, e.g. hydrogen peroxide or sodium hydrosulphite, sodium chloride, water glass, sodium hydroxide, urea, calcined sodium carbonate and the sodium salts of diethylene triamine penta acetic acid and ethylene diamine tetra-acetic acid. The impregnated material may be passed continuously through a steamer and steamed for 1-20 minutes at 100 DEG -120 DEG C. or it may be rolled up and steamed for 1-4 hours at 80 DEG -100 DEG C. in a closed chamber.