GB925570A - Improved flame resistant polyurethanes - Google Patents

Abstract

In a process for the manufacture of flameresistant polyurethane products by reaction of polyesters with organic polyisocyanates, there is used a polyester made from reactants which include a proportion of an organic phosphorus compound containing a plurality of esterforming substituents joined to the phosphorus atom by a direct carbon-phosphorus bond. Water, and/or volatile liquids may be present in the reaction mixture, to give foamed cellular materials. Hydroxyalkyl and carboxyalkyl are specified ester-forming substituents, tris-(hydroxymethyl) phosphine oxide and tetrakis-(hydroxymethyl) phosphonium compounds, for example the chloride and acetate, being specifically referred to. When the latter compounds are used, they are preferably first heated with the polycarboxylic acid so that monofunctional acid liberated is removed by volatilization before the reaction with the other polyester-forming components is effected. Suitable polycarboxylic acids are succinic, glutaric, adipic, sebacic, suberic, azelaic, phthalic, isophthalic, terephthalic and trimesic acids, polymerized fatty acid, tetrachlorophthalic acid and 1:4:5:6:7:7 - hexachlorobicyclo - (2:2:1) - 5 - heptene-2:5-dicarboxylic acid. Ethylene, propylene, diethylene, tetramethylene, hexamethylene, and 1:3-butylene glycols, trimethylol-ethane or propane and pentaerythritol are suitable polyhydric alcohols. Hydroxy acids, aminoalcohols, polyamines and oils can also be included in the ester-forming reaction mixture. Polyethers and/or other polyesters can be used together with the phosphorus-containing polyesters. Tri-(2-chloroethyl) phosphate and chlorinated paraffin wax can be added in preparing the polyurethanes. In examples (1) a polyester is prepared by heating adipic acid, phthalic anhydride and tetrakis-(hydroxymethyl) phosphonium chloride up to 200 DEG C., then cooling to 100 DEG C. and reacting with pentaerythritol and butylene-1,3-diol. The polyester is reacted with an aqueous solution of an octylcresol/ethylene oxide condensate and a crude diphenylmethane diisocyanate to give a foam; (2) a prepolymer is prepared by reacting 2:4- and 2:6-tolylene diisocyanates with a polyester (A) containing benzoyl chloride, from trimethylolpropane and the mixture obtained by heating adipic acid and tetrakis-(hydroxymethyl) phosphonium chloride with distallation of volatile material. Foam is prepared by reacting prepolymer and monofluorotrichloromethane with a mixture of polyester A, aqueous dimethylbenzylamine lactate and polysiloxaneoxyalkylene copolymer; (3) poly(ethylene/propylene) ether glycol and triethanolamine are present in the final reaction mixture in a similar process.ALSO:In a process for the manufacture of flame-resistant polyurethane products by reaction of polyesters with organic polyisocyanates, there is used a polyester made from reactants which include a proportion of an organic phosphorus compound containing a plurality of ester-forming substituents joined to the phosphorus atom by a direct carbon-phosphorus bond. Water, and/or volatile liquids may be present in the reaction mixture, to give foamed cellular materials. Hydroxyalkyl and carboxyalkyl are specified ester-forming substituents, tris-(hydroxymethyl) phosphine oxide and tetrakis-(hydroxymethyl) phosphonium compounds, for example the chloride and acetate, being specifically referred to. When the latter compounds are used, they are preferably first heated with the polycarboxylic acid so that monofunctional acid liberated is removed by volatilisation before the reaction with the other polyester-forming components is effected. Suitable polycarboxylic acids are succinic, glutaric, adipic, sebacic, suberic, azelaic, phthalic, isophthalic, terephthalic and trimesic acids, polymerised fatty acid, tetrachlorophthalic acid and 1 : 4 : 5 : 6 : 7 : 7-hexachlorobicyclo (2 : 2 : 1)-5-heptene- 2 : 5-dicarboxylic acid. Ethylene, propylene, diethylene, tetramethylene, hexamethylene, and 1 : 3-butylene glycols, trimethylol-ethane or propane and pentaerythritol are suitable polyhydric alcohols. Hydroxy acids, amino-alcohols, polyamines and oils can also be included in the ester-forming reaction mixture. Polyethers and/or other polyesters can be used together with the phosphorus-containing polyesters. Tri-(2-chloroethyl) phosphate and chlorinated paraffin wax can be added in preparing the polyurethanes. In examples (1) a polyester is prepared by heating adipic acid, phthalic anhydride and tetrakis (hydroxymethyl)-phosphonium chloride up to 200 DEG C., then cooling to 100 DEG C. and reacting with pentaerythritol and butylene-1, 3-diol. The polyester is reacted with an aqueous solution of an octyl-cresol/ethylene oxide condensate and a crude diphenylmethane diisocyanate to give a foam; (2) a prepolymer is prepared by reacting 2 : 4- and 2 : 6-tolylene diisocyanates with a polyester (A) containing benzoyl chloride, from tremethylolpropane and the mixture obtained by heating adipic acid and tetrakis-(hydroxymethyl) phosphonium chloride with distillation of volatile material. Foam is prepared by reacting prepolymer and mono-fluorotrichloromethane with a mixture of polyester A, aqueous dimethylbenzylamine lactate and polysiloxane-oxyalkylene copolymer; (3) poly (ethylene/propylene) ether glycol and triethanloamine are present in the final reaction mixture in a similar process.