Patent GB-843720-A (GB)
Title: Improvements in dyeing textile materials of natural or regenerated cellulose
IPC: D06P1/52
Filed: 1958-03-12
Abstract: Textile materials of natural or regenerated cellulose are dyed, and may be finished, with a water-soluble or difficulty water-soluble metal complex dyestuff in the presence of an acid or acid-reacting substance together with a hardenable aminoplast-forming substance and/or a primary component of such a substance (as defined below) and an aldehyde or a compound which splits off formaldehyde, and the material is then subjected to treatment at an elevated temperature. Hardenable aminoplast-forming substances are methylol derivatives of nitrogenous compounds, having a low molecular weight, and are defined as compounds which contain at least once and up to ten times in the molecule the group <FORM:0843720/IV (c)/1> , where X is O, S, or NH, R may be hydrogen, or an alkyl, cycloalkyl or aryl radical in which the carbon chain or ring may be interrupted by hetero atoms, and R1 may be hydrogen or an alkyl radical.  Examples include dimethylolurea, dimethyldimethylolurea, dimethyloldicyandiamide, methylolthiourea, dimethylolguanidine, trimethylolmelamine, triphenyltrimethylolmelamine, diphenyldimethylolurea, methylolderivatives of mono- and di-ureides, carboxylic acid amides and diamides, urethanes and polyurethanes (e.g. butane-dioldiurethane), and methylol derivatives of triazones, lactams, polyamides and ethyleneureas.  Primary components of aminoplast-forming substances are defined as compounds containing at least once in the molecule the group <FORM:0843720/IV (c)/2> (symbols as above).  Examples include urea, thiourea, dicyandiamide, dicyandiamidine, guanidine, and melamine. Suitable aldehydes include formaldehyde, glyoxal and acetaldehyde and suitable compounds splitting off formaldehyde include paraformaldehyde and hexamethylene tetramine.  Suitable acids include boric, phosphoric, formic, acetic, glycollic, tartaric, chloracetic, chlorpropionic, citric and maleic acids, and suitable acidreacting compounds include ammonium or amine salts of stronger inorganic and organic acids, e.g. ammonium chloride and diethanolamine hydrochloride.  The reagents applied to the material may also include wetting, hydrophobing, softening and finishing agents, and solutions or dispersions of synthetic resins. After dyeing and drying, the material may be subjected to a mechanical treatment, e.g. embossing, calendering, or friction finishing, and may be again heated to an elevated temperature after the mechanical treatment.  In a typical example, a bleached and mercerised cotton fabric is foularded at 50-70 DEG C. with a dyebath containing, per litre, 20 gms. of the bluish-red chromiumcontaining monoazo dyestuff derived from diazotised 1-hydroxy-2-amino-5- nitrobenzene, 1-phenyl-3 methyl-5 pyrazolone, and 2 hydroxybenzoic acid (Specification 692,073), 90 gms. of dimethyldimethylolurea and 4 gms. of monoammonium phosphate.  The fabric is then squeezed, dried at about 120 DEG C. and then heated for 4 mins. at 150 DEG C.  A fast dyeing is obtained and the fabric has good crease-resistance. Specifications 424,625, 667,168, 711,766, 747,367, 766,402 and 793,136 also are referred to.