| 摘要 |
<p>A fire-retardant coating composition comprises an aqueous dispersion of a mixture of a latex-like dispersion of a film-forming polymeric material in an amount of 30 to 15 per cent of the solid content of the mixture, and 70 to 85 per cent of non-film-forming fire-retardant solids which consists essentially of (1) a foam-forming substance selected from monoammonium phosphate, diammonium phosphate, phosphoric acid, ammonium sulphate, sulphamic acid, ammonium sulphamate, ammonium bromide, sodium tungstate and sodium borate; (2) from 10 to 70 per cent by weight of the foam-forming substance, of one or more polyhydric compounds selected from starch, the hexitols, the pentitols and the mono-, and ditetritols; and (3) from 0 to 55 per cent based on the weight of (1), of a compound selected from glycine, urea dimethyl urea, guanyl urea, guanidine, and dicyandiamide. When a starch is used as ingredient (2) it is present in an amount less than 15 per cent by weight of (1). The composition may also contain other ingredients such as thickening agents, e.g. sodium alginate, low viscosity methyl cellulose, gum tragacanth, gum arabic, or Irish moss, pigments, e.g. titanium dioxide, and fungicides and bactericides such as sodium pentachlorophenolate, beta naphthol, copper fluoride, boric acid, borax, zinc salts, arsenates, or arsenites. Filmforming materials mentioned are polyvinyl chloride, copolymers of vinyl chloride with vinylidene chloride or vinyl esters, copolymers of styrene and butadiene and copolymers of vinylidene chloride and acrylonitrile. The polyhydric compound may be pearl corn starch, mannitol, arabitol, mono dipentaerythritol or a dimer of pentaerythritol. The compositions may be used to coating buildings materials, e.g. fibre board.</p> |
