Patent GB-796815-A (GB)
Title: Improvements in and relating to the production of an aminoplast precondensate for the treatment of cellulosic textile materials
Inventor: DAUL GEORGE CECIL
IPC: C08G12/02
Filed: 1955-02-22
Abstract: Stable, water-soluble, resin precondensates are obtained by reacting one or more "formaldehyde - resin" - forming amino compounds having at least two amino groups in the molecule and containing the group <FORM:0796815/IV (b)/1> in which X is O or =NR, R representing H or the fragment <FORM:0796815/IV (b)/2> the other end of which is directly attached to one of the other nitrogen atoms, with an epihalogenhydrin and reacting the product with formaldehyde or a compound capable of generating formaldehyde under the reaction conditions.  Amino compounds specified are urea, melamine, guanidine, dicyandiamide and mixtures of urea and melamine.  The reaction is preferably conducted in two stages using an aqueous medium, the pH being preferably maintained at 8 during the reaction by the addition of NaOH.  The reaction between urea, epichlorhydrin and formaldehyde is stated to yield the possible products: HOCH2-NH-CO-NH-CH2-CH(OH)-CH2Cl, <FORM:0796815/IV (b)/3> and the reaction products of these compounds with each other and with other methylol compounds present.  The products may be stabilized for long periods against further condensation by the addition of sodium hydroxide pellets.  In the examples, urea, epichlorhydrin and formaldehyde are reacted in the ratios 1 : 0.4 : 1.6, 1 : 0.5 : 1.5, 1 : 0.3 : 1.7, 1 : 0.2 : 1.8, 1 : 0.1 : 1.9 and 1 : 0.5 : 2; melamine, epichlorhydrin and formaldehyde are reacted in the ratios 1 : 0.5 : 3, 1 : 0.5 : 4, 1 : 0.75 : 3, 1 : 1 : 3 and 1 : 2 : 4; dicyandiamide, epichlorhydrin and formaldehyde are reacted in the ratios 1 : 0.5 : 3 and 1 : 1 : 1.5; guanidine, epichlorhydrin and formaldehyde are reacted in the ratios 1 : 0.5 : 2, 1 : 0.5 : 3 and 1 : 1 : 2; and melamine, urea, epichlorhydrin and formaldehyde are reacted in the ratios 1 : 1 : 1 : 5, 1 : 1 : 1 : 4, 1 : 1 : 1 : 3, 1 : 1 : 1.5 : 4 and 1 : 1 : 1.5 : 3.ALSO:Textile fabrics are treated with a stable water-soluble resinous precondensate and then heated to insolubilise the resin on the fabric, the precondensate being obtained by interacting an amino compound having at least two amino groups in the molecule and containing the molecular fragment <FORM:0796815/IV (b)/1> in which X is O or NR, where R is H or the fragment <FORM:0796815/IV (b)/2> the other end of which is attached to one of the other N atoms, with an epihalohydrin and reacting the product obtained with formaldehyde or a compound generating formaldehyde under the reaction conditions.  Amino compounds specified are urea, melamine, guanidine and dicyandiamide.  The impregnating solution for treating cellulosic textiles may contain sodium oleate and oleic acid and a water-repellent material, e.g. stearamidomethyl pyridinium chloride or a silicone.  In examples: (1) an aqueous condensate obtained by reacting an aqueous solution of urea, formaldehyde and epichlorhydrin and neutralizing the product with NaOH solution is incorporated in an aqueous solution containing sodium oleate and oleic acid and applied to viscose rayon, which is then squeezed through a ringer and dried in a blower oven at 110 DEG C.  Similar precondensates are obtained (Example 10) by reacting 1 mol. urea, 0.5 mols. epichlorhydrin and 1 mol. melamine, and (Example 11) by reacting melamine epichlorhydrin and formaldehyde in the molar ratio 1 : 0.5 : 3; viscose rayon staple fibre is treated with a 12 per cent solution of this precondensate containing 0.2 per cent of a cationic softening agent at pH 7.5; (Example 16) dicyandiamide is reacted with epichlorhydrin and the product is neutralized with NaOH and then reacted with formaldehyde; (Example 18) the precondensate is formed by reacting guanidine, epichlorhydrin and formaldehyde in molar ratios of 1 : 0.5 : 2, 1 : 0.5 : 3 and 1 : 1 : 3.ALSO:A stable water-soluble resinous precondensate suitable for impregnating textiles which are then heated to insolubilize the resin on the fabric is obtained by interacting an amino compound having at least two NH2 groups in the molecule and containing the molecular fragment <FORM:0796815/IV (a)/1> in which X=O or NR where R is H or the fragment <FORM:0796815/IV (a)/2> the other end of which is attached to one of the other N atoms with an epihalohydrogen and reacting the product obtained with formaldehyde or compound generating formaldehyde under the reaction conditions.  Amino compounds specified are urea, melamine, guanidine and dicyandiamide.  In Example (1) 60 gs. urea, 25 c.cm. water and 120 gs. of a neutral 40 per cent formaldehyde solution are stirred together and 30.9 c.cs. epichlorhydrin added dropwise and the mixture heated for one hour at 70 DEG  C.  The product is neutralized with NaOH filtered and bottled.  On chilling with ice a paste is formed which after purification is used in an aqueous 0.15 per cent solution of sodium oleate and 0.15 per cent oleic acid to impregnate viscose rayon which is then passed through a wringer and dried at 110 DEG  C. Other examples describe condensates in which the amino compound is melamine and urea (Examples 11, 19 and 23), including (Examples 11 and 15), dicyandiamide (Examples 16 and 17), and guanidine (Example 18).