Patent GB-1058705-A (GB)
Title: Improvements in or relating to a method of forming a fire-retardant adhesive bond
IPC: C08G12/04
Filed: 1964-04-06
Abstract: Adhesive bonds between surfaces are formed using a composition comprising a condensate of an aminoplast-forming compound comprising dicyandiamide and an aldehyde prepared at least in part in the presence of phosphate ions amounting to at least 4.1% of the total dry weight of the amino-compound and the aldehyde. Suitable compositions are derived from 1-5 moles of dicyandiamide, 0-3.5 moles of urea, 0-2 moles of melamine, 0.5-4 moles of an ammonium phosphate, water (q.s., preferably 10-60 wt. per cent of the condensate solids), and at least 0.75 moles of formaldehyde per mole of amino-compound, any amino-compound in excess of the 1:1 ratio being dicyandiamide. Suitable amino-compounds besides dicyandiamide are polyalkylol derivatives of melamine, guanamines, and ammeline, containing up to an equivalent amount of urea or dicyandiamide or guanidine. Other suitable aldehydes are acetaldehyde and hydroxyaldehydes. The phosphate ions may derive from phosphoric acid or acid salts thereof, particularly ammonium salts.  Other mineral acids, e.g. HCl, H3BO3 and HSO3NH2 may be present. The composition preferably also contains a skeleton-forming compound, e.g. dextrin, starch, sugar, protein or animal glue, and possibly, softeners, e.g. tricresylphosphate, trichlorethylphosphate, dibutyl- or trioctyl-phthalate, diluents, e.g. ethylene or butylene glycol or diethylene glycol monoethyl ether, and/or water-binders, e.g. lactic acid and salts and esters thereof, sorbitol, mannitol, penta- and dipenta-erythritol, glycerol, trimethylolethane or -propane and 2:2-dimethylol -1:5-dihydroxypentane.  The skeleton-forming compound may amount to up to 25%, the softener, diluent or water-binder to up to 10% each of the total composition weight. In examples compositions are prepared from (1 and 2)-dicyandiamide/urea/formaldehyde, ammonium dihydrogen phosphate and dextrin, (3) dicyandiamide/formaldehyde, ammonium dihydrogen phosphate and dextrin, (4) a condensate of melamine, formalin, paraldehyde, butane-1:4-diol and ethylene glycol monoethyl ether, mixed with an aqueous solution of dicyandiamide, formalin, paraldehyde, HCl, H3PO4 and dextrin, and (5) as (4) using methanol for the ethylene glycol monoethyl ether and ethylene glycol in place of HCl.ALSO:Fabrics, paper or wooden surfaces may be coated with a fire-retardant composition comprising a condensate prepared from an aminoplast-forming compound comprising dicyandiamide and an aldehyde, at least in part in the presence of phosphate ions amounting at least to 4.1% of the total anhydrous weight of the amino-compound and the aldehyde.  The product may be an adhesive tape.  Numerous amines may be present during the condensation reaction.  Additives to the adhesive compositions are listed.  In examples spruce panels are coated with aqueous compositions comprising (1) dicyandiamide/urea/formaldehyde, NH4 H2PO4 and dextrin, (4 and 5) condensates from dicyandiamide, melamine, formaldehyde, phosphoric acid, dextrin, ethylene glycol (or its monoethyl ether) and HCl or butane-1:4-diol.