Patent GB-730018-A (GB)
Title: Manufacture of new condensation products of aldehydes and guanyl-melamines
Filed: 1952-04-23
Abstract: A fabric is treated with an aqueous solution of a guanyl-melamine/formaldehyde condensate (see Group IV (a)) whereby (1) prints or dyeings thereon made from dyestuffs containing carboxyl or sulphonic acid groups are rendered wet-fast and (2) the fabric is rendered crease-resistant.  Specified fabrics are wool, silk, cotton, linen, artificial silk and regenerated cellulose.  The treatment is preferably performed at 70-75 DEG  C. and may be combined with an after-treatment with a water-soluble copper salt, e.g. a non-complex inorganic or organic copper salt, a complex of an inorganic or organic copper salt and ammonia or an amine, or a complex copper compound of a hydroxy-carboxylic acid. A treatment bath containing both the guanyl-melamine condensate and the copper salt may be used or the fabric may be treated first with the condensate and then with the copper salt.  When copper compounds are used the dyestuff used is preferably one containing the grouping <FORM:0730018/IV (c)/1> in which the pair of carbon atoms bound to X belongs to a cyclic diazo compound, the pair of carbon atoms to which the hydroxyl group is bound are those of any desired coupling component and X is an OH or COOH group.  The dyestuff may also contain further groupings capable of forming metal complexes, e.g. the salicylic acid grouping.  In examples: (9) A fabric of staple fibres of regenerated cellulose which has been dyed with the symmetrical urea compound of the monoazo-dyestuff from diazotized 1 - amino - 8 - hydroxynaphthalene - 3,6 - disulphonic acid and 1-amino-2-methoxy-5-methyl-benzene is treated with an aqueous solution containing (a) a condensate of a mixture of mono-, di- and tri-guanyl-melamine hydrochlorides and formaldehyde; (b) methylol urea; (c) ammonium chloride; and (d) copper acetate; the fabric is then dried, washed with a solution containing sodium carbonate and a synthetic detergent and rinsed and dried.  (10) A cotton fabric which has been dyed with the copper compound of the azo-dyestuff from tetrazotized dianisidine and hydroxy-naphthalene-2,6-disulphonic acid is treated with a condensate of a mixture of mono-, di- and tri-guanyl melamines and formaldehyde. (11) A cotton fabric which has been dyed with the copper compound of the dyestuff from tetrazotized dianisidine and 2 - oxynaphthalene - 3 : 6 - disulphonic acid is treated with an aqueous solution of the condensate used in example 9. Specification 653,520, [Group IV (b)], and U.S.A. Specification 2,537,834 are referred to.ALSO:A condensation product is made by reacting a guanyl melamine or a salt thereof with an aldehyde (e.g. formaldehyde, acetaldehyde or acrolein).  The guanyl melamine may be monoguanyl-melamine of formula <FORM:0730018/IV (a)/1> or diguanyl-melamine or triguanyl-melamine, all obtained by heating dicyandiamide with a hydrogen halide under anhydrous conditions (see Group IV (b) and Specification 635,520), or it may be a substituted monoguanyl-melamine of formula <FORM:0730018/IV (a)/2> in which R represents an aliphatic, alicyclic, araliphatic, aromatic or hetrocyclic residue and R1 represents hydrogen or a radical identical with R; these compounds being obtained by condensing monocyano-melamine with an amine (see U.S.A. Specification 2,537,834).  Condensation is performed in aqueous medium, if desired in presence of methyl alcohol, ethyl alcohol or dioxane, at room temperature to 100 DEG  C., and in neutral, acid or alkaline medium.  Preferably 2-6 mols. of formaldehyde are used per mol. of guanyl melamine.  The condensates may be after-condensed with an organic or inorganic acid salt of ammonia or a primary, secondary or tertiary aromatic, araliphatic, cycloaliphatic, hetrocyclic or aliphatic amine which may contain one or a plurality of amine groups and may contain further constituents (e.g. hydroxy groups).  The after-condensation is performed in presence of a solvent for the condensate, e.g. water, formic or acetic acid, pyridine or a lower alcohol. Alternatively, the guanyl melamine, aldehyde and ammonium or amine salt may be simultaneously condensed.  Aqueous solutions of the condensates are used to treat textiles to render them crease-resistant and to improve the wet fastness of dyeings or prints thereon (see Group IV (c)).  The treatment bath may also contain a copper salt, e.g. a non-complex inorganic or organic copper salt; a complex copper salt derived from an inorganic or organic copper salt and ammonia or an amine; or a copper complex of a hydroxy carboxylic acid.  In examples: (1) and (4) a mixture of guanylmelamine hydrochlorides obtained from dicyandiamide and hydrogen chloride is condensed with formaldehyde in neutral medium; (3) the reactants of example (1) are condensed in presence of glacial acetic acid; (2) a mixture of guanyl melamines obtained by treating the guanylmelamine hydrochlorides of examples (1) and (3) with sodium hydroxide is condensed with formaldehyde in neutral medium; (5) a condensate similar to that of example (2) is dissolved in water and heated at 80-85 DEG  C. with ammonium chloride; (6) a condensate similar to that of example (2) is dissolved in formic acid, heated to 60 DEG  C. with ammonium chloride, diluted with water and heated in a boiling water bath; (7) a condensate similar to that of example (2) is dissolved in formic acid, heated with pyridine hydrochloride or ethylene diamine hydrochloride, diluted with water and further heated in a boiling water bath; (9) a dyed regenerated cellulose fabric is treated with an aqueous solution containing the condensate of example (1), methylol urea, ammonium chloride and copper acetate; (10) and (11) a cotton fabric is treated with an aqueous solution of the condensate of examples (1) or (2).ALSO:A mixture of mono-, di- and tri-guanyl melamine hydrohalides is made by treating dicyandiamide in an inert solvent and at a raised temperature with a gaseous hydrogen halide. The free amines may be recovered from the hydrohalides by adding a strong alkali.  In examples: (1) a mixture of pyridine and nitrobenzene is saturated with hydrogen chloride at 90 DEG  C., and after heating to 110 DEG  C., dicyandiamide is added in small portions while introducing hydrogen chloride.  When the addition is complete the whole is heated for 15 minutes at 110 DEG  C. with the introduction of hydrogen chloride, cooled to 50 DEG  C., and the solid reaction products dissolved in water adjusted to pH 5-9 with ammonia.  The solution is then cooled to separate the guanylmelamine hydrochlorides; (2) dicyandiamide is dissolved in hot phenol and hydrogen chloride introduced at 120 DEG  C.  After cooling, the reaction mass is mixed with acetone and the precipitated hydrochlorides washed with acetone and dried.  The free bases are recovered by reacting the hydrochlorides with aqueous sodium hydroxide solution; (4) dicyandiamide is suspended in toluene and hydrogen chloride introduced while heating on a boiling water bath. After cooling the residues are separated and dried.  Specification 653,520 is referred to.