Patent GB-592307-A (GB)
Title: Process for dyeing fibrous materials
IPC: D06P1/56
Filed: 1944-10-27
Abstract: Fibres which have no affinity for metallised or non-metallised acid wool or direct dyestuffs and do not absorb water, e.g. fibres of glass or vinyl polymerizates, are dyed with the aforesaid dyestuffs by immersion prior to the dyeing in an aqueous solution of a water-soluble reaction product of formaldehyde and an acyclic compound of the urea group which has at least once the atomic grouping: <FORM:0592307/IV/1> and consists of elements having an atomic weight not greater than 16 and in which the proportion of oxygen when present relatively to carbon is lower than that in urea. After immersion, dyeing may be carried out either directly or after rinsing or also after drying at ordinary or at raised temperature. Deeper tints may be obtained by repeating the whole process.  The fibres may be pretreated with an acid or alkali prior to treatment with the aforesaid reaction product, e.g. glass fibres may be pretreated with hydrofluoric acid.  The lustre of fibres of vinyl polymerizates which is diminished by the dyeing treatment, may be restored by means of an aqueous solution of a known swelling agent, e.g. phenol, resorcinol, diethylene glycol or acetin.  In examples, fibres of glass or Vinyon are immersed in an aqueous solution of the reaction product of formaldehyde with dicyandiamidine, guanidine, cyanamide or dicyandiamide and dyed with; (1) Benzyl Violet 5BN, Amido Yellow E, Kiton Fast Red 4BL, Brilliant Kiton B or Wool Green S; (2) Direct Fast Orange SE, Direct Fast Scarlet SE, Direct Brown M, Direct Sky Blue green shade, Cotton Blue N or Melantherine BH; (3) the complex copper compounds of the azodyestuffs (a) 1-amino-4-hydroxy - benzene - 5 - sulphonamide (2 mols.) \sQ 5 : 51-dihydroxy - 2 : 21-dinaphthylamine-7 : 71-disulphonic acid, (b) salicylic acid \sM 4 : 41-diaminodiphenyl \sM resorcinol \sM 1-amino - 2 - hydroxybenzene - 4 - sulphonic acid; (4) the complex chromium compounds of the azo-dyestuffs (a) 1-amino-2-hydroxybenzene-4-sulphonamide --> 1 - (31 - sulphonamido) - phenyl-3-methyl-5-pyrazolone, (b) 1-hydroxy-2-amino-4-nitrobenzene-6-sulphonic acid \sM 1-phenyl-3-methyl-5-pyrazolone, (c) 1-amino-2-hydroxynaphthalene - 4 - sulphonic acid --> 1 - (31 - sulphonamido) - phenyl - 3 - methyl - 5 - pyrazolone, (d) 1 - hydroxy - 2 - amino - 5 - nitro - benzene --> 2-aminonaphthalene-6-sulphonic acid, and the complex copper compound of the azo-dyestuff from 1-phenyl-3-methyl-5-pyrazolone and the diazo compound of the leucotriphenyl-methane dyestuff obtained by condensing 2 mols. of dimethylaniline with 1 mol. of m - hydroxybenzaldehyde, disulphonating, nitrating and reducing the condensation product. Specifications 515,847 and 559,329 are referred to.  Samples have been furnished under Sect. 2 (5) of glass and Vinyon fibres pretreated as in example (1) and dyed with the sulphonated copper compound of phthalocyanine.  The Specification as open to inspection under Sect. 91 contains an additional example describing the treatment of glass with a hydrophobic condensation product of melamine and formaldehyde which is then dyed with Benzyl Violet 5BN.  This subject-matter does not appear in the Specification as accepted.