GB832227A - Process for adhering wooden surfaces - Google Patents

Abstract

An adhesive composition for uniting wooden surfaces comprises an alkaline aqueous dispersion of a copolymer of 30-80 weight per cent of a monocyclic vinyl aromatic hydrocarbon with a conjugated diolefine having four to six carbon atoms, and a water-dispersible protein which is at least partially soluble in alkali, there being 30-300 parts by weight of copolymer per 100 parts of protein. The vinyl aromatic compound may be styrene, vinyl toluene or vinyl xylene; the diolefine may be butadiene; isoprene; 1,3-pentadiene; 2-ethylbutadiene or 2,3-dimethylbutadiene. Specified proteins are casein, soluble blood, soyabean proteins, zein and peanut protein, separately or mixed. For each 100 parts of solids 100-300 parts of water are added. Inorganic material in an amount of 10-50 parts per 100 parts protein is added to make the dispersion alkaline, e.g. pH 9-12, and so enhance the solubility of the protein. Such additives are compounds of the alkali or alkali earth metals including the fluorides, carbonates, chlorides, phosphates, oxides and hydroxides. Other additions may include a defoaming oil such as pine oil or fusel oil, a bactericide such as pentachlorophenol, a fibrous filler such as wood flour and an inorganic filler such as mica. The dispersion may be prepared by dispersing the protein in an aqueous alkaline medium and adding this to a latex of the polymer or by mixing the polymer in the dry powdered form with the protein and dispersing this mixture in the aqueous medium.ALSO:An adhesive composition for uniting wooden surfaces comprises an alkaline aqueous dispersion of a copolymer of 30-80% of a monocyclic vinyl aromatic hydrocarbon with a conjugated diolefine having 4-6 carbon atoms, and a water-dispersible protein which is at least partially soluble in alkali. Specified proteins are casein, soluble blood, soyabean protein, zein and peanut protein. For each 100 parts of solids 100-300 parts of water are added. Inorganic material in an amount of 10-50 parts per 100 parts of protein is added to produce a dispersion of pH 9-12 to enhance solubility of the protein, such additions being alkali or alkaline earth fluorides, carbonates, chlorides, phosphates, oxides and hydroxides. Other additions may include a defoaming oil, e.g. pine oil or fusel oil, a bactericide such as pentachlorophenol, a fibrous filler such as wood flour, an inorganic filler such as mica. The protein may be dispersed in the aqueous alkaline medium, and this dispersion added to a latex of the copolymer, or a mixture of the copolymer in dry powdered form and the protein may be dispersed in the aqueous medium.