Patent GB-1308468-A (GB)
IPC: C08J9/40
Filed: 1970-03-06
Abstract: 1308468 Coated foams BAYER AG 6 March 1970 [7 March 1969 (3) 23 Oct 1969] 10833/70 Heading B2E [Also in Division C3] At least partly open celled foams are erreversibly increased in volume by causing the foam to swell and rendering at least the major part of the swelling permanent by treating the foam with one or more reagents which react to produce solids in the cells of the foam. The reagents may undergo an addition or polyaddition reaction, a condensation or polycondensation reaction, a radical or ion-catalysed polymerization, copolymerization or graft polymerization reaction involving a saturated or unsaturated polymerizable monomer, an oxidation, reducing or ionic reaction, a diazonium salt formation reaction or a cross-linking polymer precipitation reaction. The foams may be in the form of films, cellular mouldings, e.g. blocks, spheres or cylindrical mouldings, or particles which may be subsequently bonded together during shaping or forming. Preferred foams include open-cell foams containing urethane groups and/or urea groups and/or amide groups and/or isocyanurate groups, e.g. polyurethane foams. Other foams mentioned include polyamides, modified phenol-formaldehyde resins, aminoplast foams, polystyrene, ABS polymers, polyvinyl chloride, polycarbonates, natural rubber or synthetic rubber foams. The foams used may be impregnated with latices, emulsions or dispersions of, e.g. polyvinyl chloride, polyvinyl acetate, ethylenevinyl chloride copolymers containing polychlorobutadiene, natural rubber latex or tar and optionally fillers and pigments. Preferably at least one of the reagents is introduced into the foam in the form of a gas, vapour or mist. Examples of addition or poly-addition reactions are: additions of monoisocyanates and polyisocyanates with gaseous ammonia; poly-additions of polyepoxides prepared from bisphenol A and epichlorohydrin with gaseous ammonia and/or ethylene diamine and/or diethylene triamine vapours; poly-addition reactions involving cyanic acid esters and/or a polycyanic acid ester, optionally in the presence of a polymerizable vinyl monomer, with gaseous ammonia, ethylene diamine and/or triethylene tetramine vapours; poly-addition reactions involving a polyamine and/or polyamido amine with gaseous acrylonitrile and/or formaldehyde; poly-addition reactions of polycarboxylic acids with gaseous methoxymethyl isocyanate; the addition of gaseous chloral with dimethyl or diethyl phosphite; the addition and polyaddition reactions involving urea, thiourea, dicyandiamide, melamine, aniline, 4, 4'- diamino - diphenyl methane, hexamethylene diamine, isophorone diamine and/or xylylene diamine, phenol, 4,4'-dihydroxydiphenyl dimethylmethane, resorcinol, pyrocatechol, pyrogallol or cyclohexane with gaseous formaldehyde, chloral or acrolein. Suitable polymerization reactions include: polymerization of an olefinically unsaturated compound in the presence of gaseous propylene oxide, vinyl chloride, acrylonitrile or sulphur dioxide; polymerization reactions involving ethylene oxide, propylene oxide, epichlorohydrin, ethylene sulphide, phenyl glycidyl ether, styrene oxide, cyclohexene oxide, glycol carbonate or propiolactone in the presence of gaseous ethylene oxide or propylene oxide; polymerization reactions involving caprolactam in the presence of caprolactam vapour and gaseous methoxymethyl isocyanate as co-catalyst; polymerization of cyclopentadiene, dicyclopentadiene, cyclopentene, butadiene or ethylene with gaseous sulphur dioxide; polymerization of acrylic acid, methacrylic acid, maleic acid, a maleic acid half ester or styrene in the presence of gaseous sulphur dioxide; coupled polymerization and poly-addition involving styrene, maleic acid and fumaric acid anhydride, their esters or polyesters with isocyanatoethyl methacrylate and gaseous ammonia and/or ethylene diamine; polymerization reaction catalyzed by free radical generators or by light, heat or highenergy radiation involving styrene, vinyl chloride, vinylidene chloride, vinyl acetate, alpha-methyl-styrene, methylacrylate, butylacrylate, methylmethacrylate, N-methylol-methacrylimide methylether, maleic acid triethylene glycol half-ester or icyanatoethylmethacrylate, beta-hydroxy propylmethacrylate, maleic acid and fumaric acid half-esters, di-esters or polybeta-hydroxy propylmethacrylate, maleic acid esters or glycidyl methacrylate in the presence of gaseous sulphur dioxide, vinyl chloride, formaldehyde or formic acid; the polymerization of formaldehyde and/or a compound which yields formaldehyde and/or thioformaldehyde an/or trioxane optionally in the presence of cyclic acetals, cyclic ethers or thioethers, cyclic carbonates, vinyl monomers or trichloro or trifluoroacetaldehyde and optionally in the presence of polymerization catalysts. Examples of condensation and polycondensation reactions are: poly-condensation of cyanuric acid chloride and gaseous ammonia, methylamine or ethylamine; the polycondensation of bis-chloroformic acid ester, a polycarboxylic acid anhydride, an acid chloride and/or ester and gaseous ammonia and/or ethylene diamine; the poly-condensation of 4, 4'-dihydroxy-diphenyl dimethylmethane with gaseous phosgene in the presence of an agent which adds an acid; condensations involving a solution of latex of a polymer, copolymer, graft copolymer or poly-addition product containing hydroxyl groups or urea groups COOH groups, amino groups, amide groups or urethane groups and gaseous formaldehyde and/or methoxymethyl isocyanate; reaction of carbonyl compounds with nitrogen compounds capable of aminoplast formation optionally in the presence of low molecular weight compounds which are active against fungi, viruses, bacteria and other parasitic organisms and which contain hydrogen atoms reactive with carbonyl compounds or in the presence of inorganic plant nutrient salts which are soluble or dispersible in water. Examples of oxidation reactions are: reactions involving 0, 0'-dimethylphenol and air or gaseous oxygen in the presence of a cupric or cuprous salt; reactions involving linseed oil fatty acid glycerides and/or linseed oil fatty acid amides, urethanes or polyurethanes and air or gaseous oxygen in the presence of cobalt naphthenate; oxidation of aniline, 4, 4'-diamino-diphenylmethane, o-aminophenol, p-phenylene diamine, N, N-dimethyl aniline, or an alpha, omegadiamino polyurethane with air or oxygen in the presence of a cupric or cuprous salt and pyridene or a tertiary amine. The reducing reaction may be: the reduction of gaseous sulphur dioxide with an addition product of 1 mol of trimethylamine or triethylamine and 3 mols of formic acid thus forming sulphur. Examples of ionic reactions are: the reaction of calcium chloride, magnesium chloride, sodium silicate or aluminate solution with gaseous moist ammonia and carbon dioxide; the reaction of the hydroxide or oxide hydrate of calcium, magnesium, aluminium, barium, zinc, silicon or titanium with gaseous, moist sulphur dioxide; the reaction of antimonyl tartaric acid with gaseous ammonia. The foams may be used for industrial and building purposes where increased resistance to hydrolysis, petrol and oil is required, as filter materials, as air filters for internal combusition engines, insulating materials or eliminating and damping sound, as an anchoring medium for large quantities of fuels, for plant cultivation, as water softeners, adsorbents. Flame-retarding agents may be added to the foams either during or after their production. The products may be further processed, e.g. by moulding, extrusion, welding, coating with lacquers based on polyisocyanates, polyepoxides, alkyd resins by spraying or dipping.