Process for the optical brightening of cellulose material and material brightened thereby

摘要

Cellulosic fibres, e.g. viscose rayon fibres and cotton and linen fabrics, are brightened by impregnating them with an aqueous solution of a salt of at least one stilbene compound having the formula in which R1 and R2 are primary amine groups or secondary or tertiary amine groups containing aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic nitrogen substituents which, together with the nitrogen atom, and, if desired, an oxygen atom or a further nitrogen atom, can also form a heterocyclic ring, and R3 and R4 are halogen atoms, hydrokyl groups, alkoxy groups which may be substituted or primary, secondary or tertiary amine groups as defined for R1 and R2, and with an aqueous solution of a water-soluble polyvinyl or polyalkylene oxide compound containing one or more hydroxyl groups but no sulphonic acid groups and which may be tautomeric, and then drying them. When R1, R2, R3 and R4 are secondary or tertiary amino groups these may be methylamino, ethylamino, propylamino, b -hydroxyethylamino, b -hydroxypropylamino, b -cyanoethylamino, dimethylamino, diethylamino, bis-b -hydroxyethylamino, N-methyl-N-ethylamino, N-methyl-N-b -hydroxyethylamino, N-ethyl-N-b -hydroxyethylamino, N-methyl-N-b -hydroxypropylamino, N-ethyl-N-b -hydroxypropylamino, benzylamino, N-b -hydroxyethylbenzylamino, cyclohexylamino, N-ethylcyclohexylamino, N-b -cyanoethylcyclohexylamino, phenylamino, o, m or p-methylphenylamino, 3, 5-, 2, 5- or 3, 4-dimethylphenylamino, m or p methoxy, ethoxy, chloro, bromo, sulpho, sulphamyl or carboxy phenylamino, 2, 5 dimethyl-4-sulphophenylamino, 4-chloro-3-carboxy-phenylamino, piperidino, morpholino, carboxy-methylamino, N-methylcarboxymethylamino, 2-methoxy-ethylamino, N-methyl-2-methoxyethylamino, 2-ethoxyethylamino, or 3-methoxypropylamino groups. Suitable water-soluble hydroxyl group containing compounds are polyvinyl alcohol, partially saponified polyvinyl esters, polyvinyl pyrrolidone, polyalkylene glycols, polyaddition products of propylene oxide and ethylene oxide and addition products of higher alkanols, aliphatic mono- or polyamines or alkyl phenols having 8 or more aliphatic carbon atoms and at least 15 mols of an alkylene oxide. The stilbene compound and water-soluble hydroxyl group containing compounds may be applied to the fibres simultaneously from the same aqueous solution or in steps, and the fibres then dried at a raised temperature, e.g. 50 DEG -100 DEG C., and if desired steamed and washed. The impregnation liquors may also contain synthetic resin precondensates, e.g. hexamethylolmelamine, dimethylolurea or dimethylolethyleneurea, and the fibres after drying at temperatures up to 100 DEG C. may then be heated at 120 DEG -160 DEG C. for 1-10 minutes in the presence of a resin forming catalyst.