Patent GB-1462734-A (GB)
Title: Process for the production of flame-resistant hard foam plastics which contain urethane groups
IPC: C08L67/00
Filed: 1975-05-02
Abstract: 1462734 Polyurethane foams BAYER AG 2 May 1975 [7 May 1974] 18422/75 Heading C3R A flame resistant hard foam containing urethane groups is prepared by reacting a polyisocyanate with a compound preferably having a M.Wt. of 100 to 10,000 and containing at least 2 isocyanate-reactive hydrogen atoms, in the presence of water and/or an organic blowing agent, and a flame retarding agent which comprises a mixture of: (a) from 1-99% wt. of an addition compound of 0À1-15 mols. of a mono- and/or poly-hydric alcohol and 1 mol. of a lactam of the general formula wherein either X represents a CH-group, R is hydrogen and m is 0-9; or X is nitrogen, R is a C 1 -C 18  alkyl group, a C 7 -C 15  aralkyl group or a pyridyl group optionally substituted by one or more C 1 -C 6  alkyl groups and m is 3; part or all of the mono- and/or poly-hydric alcohol optionally being replaced by water, and (b) from 99-1% wt. of a phosphorus containing acid and/or a neutral phosphoric and/or phosphonic and/or phosphorous acid ester. Suitable lactams are butyrolactam, valerolactam, #-caprolactam, 1N-(C 1 -C 3  alkyl)-hexahydro - 1,4 - diazepinone - (3). The monohydric alcohols preferably have M.Wts. of 32-500, e.g. C 1 -C 18  alkanols. The polyhydric alcohols preferably have M.Wts. of 62-500, e.g. C 2 -C 6  alkylene glycols, ditetra C 2 -C 3 -alkylene glycols, trimethylolpropane, glycerol, pentaerythritol, hydroxyethylated mannose and saccharose and hexane-triol. The polyisocyanates may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates preferably toluene 2,4- and 2,6-diisocyanates, polyphenyl-polymethylene-polyisocyanates and polyisocyanates containing carbodiimide, urethane, allophanate, urea, isocyanurate or biuret groups. Suitable compounds of M.Wt. of 100-10,000 having at least 2 NCO-reactive hydrogen atoms include compounds containing amino, thiol and carboxyl groups but are preferably polyhydroxyl compounds, e.g. polyesters, polyethers, polythioethers, polyacetals, polycarbonates or polyester amides, numerous examples of which are listed; OH containing polybutadiene; polyethers modified by vinyl polymers; polyols containing urethane or urea groups; modified or unmodified castor oil, starch and other carbohydrates; and adducts of alkylene oxides to phenol-formaldehyde or urea-formaldehyde resins. Optional ingredients include catalysts, e.g. tertiary amines and organotin compounds, emulsifiers, foam stabilizers, reaction retarders, e.g. HCl or organic acid halides, cell regulators, e.g. paraffins, fatty alcohols or dimethylpolysiloxanes, pigments, dyes, known flame-retardants, e.g. trischloroethyl phosphate, ammonium phosphate and polyphosphate and fillers such as barium sulphate, kieselguhr, carbon black or whiting. The reaction may be carried out by the one-step, prepolymer or semi-prepolymer method. In the examples foams are prepared from an #-caprolactam/trimethylol-propane adduct, polyphenyl-polymethylene polyisocyanate, a polysiloxane stabilizer, N,N-dimethylcyclohexylamine catalyst, monofluorotrichloromethane and either (1) a compound of the formula an ethylene diamine/ethylene oxide/propylene oxide amino polyether together with either (i) tris #-chloroethylphosphate or (ii) phenylcresyl phosphate; or (2) a polyester derived from diethylene glycol/trimethylolpropane/adipic acid/phthalic acid anhydride; o-phosphoric acid; 3-benzyl-4-hydroxybiphenyl polyglycol ether as emulsifier together with either (i) a polyester derived from diethylene glycol and phthalic acid anhydride; and optionally water and the sodium salt of a sulphonated castor oil as dispersing agent; or (ii) water containing a sulphonate based wetting agent; or (iii) water and the above aminopolyether. Foams are also prepared from an e-caprolactam/trimethylolpropane adduct, o-phosphoric acid, water and either hexamethylene diisocyanate or a biuret polyisocyanate prepared from hexamethylene diisocyanate and tertiary butanol, and a minor amount of a polyethylene oxide.