GB589949A - Production of improved laminated products - Google Patents

Abstract

Adhesive compositions for laminated products (see Group VIII) comprise an N-alkoxymethyl polyamide which is hardened by the action of heat and/or acid reacting catalysts while the lamin are subjected to pressure. Particular reference is made to the use of N-methoxymethyl and N - isobutoxymethyl polyhexa - methylene adipamide in the manufacture of plywood. Suitable catalysts are maleic, p-toluene-sulphonic, phosphoric, oxalic and trichloroacetic acids; ammonium chloride, monosodium phosphate, sodium bisulphate and ethyl phosphate. The bonding medium may be in the form of a solution using as solvent aqueous methyl, ethyl, propyl or butyl alcohol, or mixtures thereof with chloroform; in the form of a preformed film; or the material such as paper, regenerated cellulose, film or fabric may be coated or impregnated with the solution, the solvent evaporated and the dried sheet used as film. In the latter method, the catalyst may be contained in the solution or applied to the dry impregnated sheet. The composition may also contain as extenders walnut and apricot shell flour, finely-ground regenerated cellulose, dry ground corn cob and Redwood flour, specially ground wood flour; mica flakes, shellac, and damar gum. Other materials which may be incorporated are phenol-formaldehyde resins, linseed oil modified, castor oil modified or butanol modified urea-formaldehyde resins, mixed glycerides of unsaturated fatty acids and beta-furylacrylic acid, hydrolysed ethylene/vinyl acetate interpolymers, polyvinyl butyral, styrene and terpene-maleic anhydride resins, sulphonamide-formaldehyde resins, bismethoxymethyl urea and rosin containing materials. Specifications 461,236 and 573,482 are referred to.