Patent GB-1030195-A (GB)
Title: Improvements in and relating to adhesives
IPC: C09J131/04
Filed: 1963-07-04
Abstract: Adhesive compositions comprise an aqueous dispersion of a partially hydrolysed water-dispersible homopolymer or copolymer of vinyl acetate containing 1 to 6 weight per cent of hydroxyl groups calculated as polyvinyl alcohol and a water - dispersible polyfunctional hydroxyl-reactive compound in amount ranging from 2 to 25 % by weight of the polymer. The vinyl acetate polymer may be a copolymer with dibutyl maleate, 2-ethylhexyl acrylate, ethyl acrylate, acrylic acid or crotonic acid, or a vinyl acetate polymer which has been made to react during its formation with a solid block copolymer of ethylene oxide and propylene oxide. Hydrolysis is preferably effected in the presence of a strong acid, e.g. hydrochloric, sulphuric, nitric, phosphoric, trichloracetic, p-toluene-sulphonic and formic acids.  The hydroxyl-reactive compound may be an aminoplast, phenolic resin, isocyanate, divinyl sulphone, epoxy resin or dialdehyde, e.g. dimethylolethyleneurea, dimethylolurea, trimethylol melamine, phenol adducts of tolylene diisocyanate, glyoxal and formaldehyde. The compositions may be applied to metals, paper and textiles, or used as a binder for non-woven fabrics, e.g. of cellulose, polyamide, polyester and vinyl resin fibres.  Examples describe the partial hydrolysis of (I) polyvinyl acetate and (XII) a vinyl acetate-dibutyl maleate copolymer in the presence of an ethylene oxidepropylene oxide block copolymer; and aqueous dispersions comprising dimethylol-ethylene urea, 2-amino-2-methylpropanol hydrochloride and (II-XI and XIII-XV) partially hydrolysed polyvinyl acetate and (XII) partially hydrolysed vinyl acetate-di-butyl maleate copolymer; and partially hydrolysed polyvinyl acetate, 2-amino - 2 - methylpropanol hydrochloride and (XVI) trimethylol melamine and (XVII) a phenol adduct of tolylene diisocyanate.ALSO:Substrates may be coated with compositions comprising an aqueous dispersion of a partially hydrolysed water-dispersible homopolymer or copolymer of vinyl acetate containing 1 to 6 weight per cent of hydroxyl groups calculated as polyvinyl alcohol and a water-dispersible polyfunctional hydroxyl-reactive compound in amount of 2 to 25 weight per cent based on the polymer, and the coatings dried at elevated temperature. Specified vinyl acetate copolymers are those with dibutyl maleate 2-ethylhexyl acrylate, ethyl acrylate, acrylic acid or crotonic acid, and polymers which have been reacted during formation with ethylene oxide/propylene oxide block copolymers.  Specified polyfunctional compounds are dimethylol ethyleneurea, dimethylol urea, trimethylol melamine, tolyene diisocyanate/pheniol adducts and glyoxal.  In Examples II and IV aluminium panels are coated with aqueous dispersions comprising partially hydrolysed polyvinyl acetate, dimethylol ethyleneurea and 2-amino-2-methylpropanol.ALSO:Non-woven fabrics may be prepared by impregnating fibrous materials such as webs of cotton, viscose, rayon, polyamide, polyester and vinyl resin fibres, with an adhesive composition comprising an aqueous dispersion of a partially hydrolysed water-dispersible homopolymer or copolymer of vinyl acetate containing 1 to 6 weight per cent of hydroxyl groups calculated as polyvinyl alcohol and a water-dispersible polyfunctional hydroxyl-reactive compound in amount of 2 to 25 weight per cent based on the polymer and drying at elevated temperature. Specified vinyl acetate copolymers are those with dibutylmaleate, 2-ethylhexyl acrylate, ethyl acrylate, acrylic acid or crotonic acid, and vinyl acetate polymers which have been reacted during formation with ethylene oxide/propylene oxide block copolymers. Specified polyfunctional compounds are dimethylolethylene urea, dimethylol urea, trimethylol melamine, tolylene diisocyanate/phenol adducts and glyoxal.  Examples describe the preparation of non-woven fabrics by impregnating viscose-cotton carded webs with aqueous dispersions comprising (III-XI and XIII-XV) partially hydrolysed polyvinyl acetate, dimethylol ethyleneurea and 2-amino-2-methyl-propanol hydrochloride; (XII) a partially hydrolysed vinyl acetate/dibutyl maleate copolymer reacted with an ethylene oxide/propylene oxide block copolymer, dimethylol ethyleneurea and 2-amino-2-methylpropanol hydrochloride; and partially hydrolysed polyvinyl acetate, 2-amino-2-methyl-propanol hydrochloride and (XVI) trimethylol melamine and (XVII) phenol adduct of tolylene diisocyanate; and drying the impregnated webs at elevated temperature.