GB1095857A - Improved fire-retardant coating composition - Google Patents

Abstract

A fire-resistant paint which swells on exposure to high temperatures comprises a volatile liquid vehicle, 35-150 parts by weight of a film-forming binder, 120-475 parts by weight of a solid foaming or sponge forming agent, and glass fibres in an amount 2-30% by weight (exclusive of the weight of any organic coating on said fibres) based on the remaining ingredients of the paint. The volatile liquid vehicle may be water or a hydrocarbon, chlorinated hydrocarbon, alcohol, ketone or ether, and the filmforming material a drying oil or starch. Foaming agents specified are dicyandiamide, melamine pyrophosphate, and polyphosphorylamide (which are preferred) and mono- or di-ammonium phosphate, phosphoric acid, guanyl urea phosphate, ammonium sulphate, sulphamic acid, ammonium sulphamate, ammonium bromide, sodium tungstate, boric acid, sodium borate and water-insoluble metaphosphates such as those of Na, K, Ca or Zn. The glass fibres may be coated with polyvinyl chloride and mixed with asbestos fibres or fillers such as clay. Other ingredients may include 40-250 parts by weight of starch or a saturated open-chain C5-C15 poly (4-8) hydroxy alcohol, 70-220 parts by weight chlorinated bi- or tri-phenyl or chlorinated paraffin wax fire retardants, 40-250 parts by weight finely-divided non-film-forming aldehyde resin such as urea- or melamineformaldehyde resins, and plasticizers, fillers, pigments, dyes, stabilizers and surface-active or wetting agents. The composition is applied to the substrate by conventional spraying, brushing or roller application. In Example 7 a paint for steel is based on gloss oil, dehydrated castor oil and linseed oil fatty acids with a cobalt drier, a thinner and titanium dioxide pigment, and contains urea-formaldehyde resin, starch, monoammonium phosphate, and uncoated and vinyl-coated glass fibres. In Example 3 an aqueous paint based on starch contains monoammonium phosphate, formaldehyde, urea, titanium dioxide, gum tragacanth, and glass fibres.ALSO:A fire-resistant paint which swells on exposure to high temperatures comprises a volatile liquid vehicle, 35-150 parts by weight of a film-forming binder, 120-475 parts by weight of a solid foaming or sponge-forming agent, and glass fibres in an amount 2-30% by weight (exclusive of the weight of any organic coating on said fibres) based on the remaining ingredients of the paint. The volatile liquid vehicle may be water, a hydrocarbon, chlorinated hydrocarbon, alcohol, ketone or ether, and the film-forming material a cellulose ester or ether such as cellulose acetate or butyrate or ethyl or hyroxyethyl cellulose, nitrocellulose, sodium carboxymethyl cellulose, chlorinated rubber, rubber hydrochloride, polyvinyl or polyvinylidene chloride, a copolymer of vinyl chloride and vinyl acetate or of vinylidene chloride with vinyl chloride or vinyl acetate, polychloroprene, an alkyd or epoxy resin, or a mixture of urea, thiourea, dicyandiamide or melamine with an aliphatic aldehyde or source thereof such as formaldehyde, paraformaldehyde, acetaldehyde, furfural, trioxan or hexamethylene tetramine, or a resin formed from such a mixture. Specified foaming agents are dicyandiamide, melamine pyrophosphate or phosphorylamide (which are preferred) and mono- or di-ammonium phosphate, phosphoric acid, guanyl urea phosphate, ammonium sulphate, sulphamic acid, ammonium sulphamate, ammonium bromide, sodium tungstate, boric acid, sodium borate, and water-insoluble metaphosphates such as those of Na, K, Ca or Zn. The glass fibres may be coated with polyvinyl chloride and mixed with asbestos fibres or fillers such as clay. Other ingredients may include 40-250 parts by weight of starch or a saturated open-chain C5-C15 poly-(4-8) hydroxy alcohol, 70-220 parts by weight chlorinated bi- or tri-phenyl or chlorinated paraffin wax fire retardants, 40-250 parts by weight finely-divided non-film-forming aldehyde resin such as urea- or melamine-formaldehyde resins, and plasticizers, fillers, pigments, dyes, stabilizers and surface-active or wetting agents. Examples 1, 2 and 8 disclose paints based on nitro-, ethyl-, or hydroxyethyl cellulose, and Examples 4, 5, 6 paints based on chlorinated rubber (or a vinyl chloride: vinyl acetate copolymer), a vinyl chloride: vinylidene chloride copolymer, and a urea-formaldehyde condensate respectively, other ingredients being from those specified above.ALSO:Substrates such as steel, wood, or synthetic plastics are protected against the effect of flames and high temperature by a coating of a fire-resistant paint which foams when exposed to elevated temperatures and comprises a volatile liquid vehicle, 35 - 150 parts film-forming binder, 120 - 475 parts solid foaming or sponge-forming agent, and 2 - 30% glass fibres, based on the other ingredients, all by weight (see Division C4 - 5). Coating is by conventional brushing, rolling or spraying In the Examples a steel beam is coated with the fire-resistant paint by means of a spray gun.