Patent GB-776468-A (GB)
Title: Acetal condensation products and process for dimensional control of textile and paper materials
IPC: D06M11/55
Filed: 1954-12-16
Abstract: Water-soluble polymers are made by condensing at least one polyalkylene glycol containing from 2 to 4 alkylene groups with at least one aldehyde in the presence of an acidic catalyst and preferably in the presence of an azeotroping liquid, e.g. toluene, benzene, xylene and ethylbenzene.  Reactants specified are: glycols-diethylene, dipropylene, dibutylene, triethylene, tetraethylene and tripropylene glycols; aldehydes-formalin, paraformaldehyde, trioxane, methylal, acetaldehyde, butanal, benzaldehyde, glyoxal and terephthalaldehyde.  Polyols such as glycerine, pentaerythritol and sorbitol may be added to the glycol(s) in amounts up to 50 mol. per cent of the glycol(s) used. The polymers may be terminated, wholly or in part, by alkyl radicals containing not more than 8 carbon atoms, e.g. by co-reacting the aldehyde and glycol with a minor amount of a half ether of a glycol.  Catalysts specified are sulphuric acid, alkane sulphonic acid, phosphoric acids, acid halides, e.g. zinc, stannic, and aluminium chlorides, and acid clays.  In examples, viscous liquids are obtained by reacting in the presence of toluene and sulphuric acid (2) diethylene and dipropylene glycols, (3) diethylene glycol and sorbitol and (5) diethylene glycol and b -methoxyethanol with paraformaldehyde, and (4) diethylene glycol with paraformaldehyde and glyoxal.  The products may be used in textile finishing (see Group IV (c)), leather and paper treating, and as hydraulic fluids, lubricants, embalming fluids, germicides and fungicides.ALSO:A water-soluble condensation product of the formula <FORM:0776468/IV(b)/1> where X and Y may be either H or -CH2OH, is obtained by heating diethylene glycol, paraformaldehyde, sulphuric acid and toluene under reflux with a moisture trap inserted between the flask and reflux condenser.  After a certain amount of water of reaction had been withdrawn from the reaction mixture, toluene was removed by heating in vacuo with agitation, and the resulting product was neutralized with dilute NaOH.  The product had a molecular weight of 480 (Rast.), a hydroxy equivalent of 220, a specific gravity of 1.155 at 34.5 DEG  C., and a refractive index N30D=1.462.ALSO:Textile materials, for example filaments, staple fabrics and garments, of cotton viscose rayon, cuprammonium rayon or hydrolysed cellulose acetate, or mixtures thereof with cellulose acetate, nylon or wool, are rendered dimensionally stable by treatment with an aqueous bath containing a water-soluble polymeric condensation product of at least one polyalkylene glycol and at least one aldehyde (see Group IV(a)), and an acidic catalyst in an amount of 5 to 200 per cent by weight of the condensation product and heating the treated materials at a curing temperature of at least 121 DEG C.  Catalysts specified are aluminium, zinc and stannic chlorides, aluminium sulphate, oxalic acid, sodium acid sulphate, sodium and potassium alums, dimethyl oxalate and ammonium chloride.  The cured fabric may then be washed lightly with a detergent and a mild akali, rinsed and dried. Examples are given.