GB1012043A - Improvements in or relating to the manufacture of polyurethane foams - Google Patents

Abstract

Polyurethane foam is produced by the interaction of a hydroxyl group containing polymer with an organic polyisocyanate in the presence with an organic polyisocyanate in the presence of water or a low-boiling point organic liquid which is inert with respect to the foam-forming ingredients, characterized in that the organic polyisocyanate is the product obtained by reacting 10 to 40% of the isocyanate groups in a tolylene diisocyanate with a polyhydric alcohol component containing at least one monomer having more than 2 OH groups per molecule. The polyhydroxy monomer optionally in a solvent may be added to the tolylene diisocyanate at 20-110 DEG C. Dihydroxy monomers may also be present. Specified polyhydroxy monomers are: glycerol, trimethylolethane, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol or reaction products of these with 1-3 mols./mol. of a 1 : 2-alkylene oxide. Mixtures of monomers containing at least 20% of each component may be used. Foam formation may be by addition of polyesters or polyesteramides of molecular weight 200-5000 or polyethers of molecular weight 200-6000. 1-10% water or 1-150% of a liquid boiling below 75 DEG C. may be added. Specified liquids are CCl3F, CBr2F2, C2Cl3F3, CCl2F2, CClF3, CHCl2F, C2Cl2F4, C2H2BrF3 or mixtures thereof optionally containing hydrocarbons. Other additives may be surface active agents, e.g. oxyethylated phenols, oxyethylated oleyl alcohol, oxyethylated sulphated methyl oleate, polysiloxanes or block copolymers thereof with alkylene oxides; catalysts, e.g. tertiary amines, dibutyltin dilaurate, stannous octoate, lead acetate, or iron or manganese acetylacetonate; stabilizers, e.g. ethyl cellulose; flame retardants, e.g. b -trichloroethyl phosphate or antimony oxide; plasticizers, e.g. dialkyl phthalate; colouring matter; or antioxidants, e.g. tert-butyl catechol and sterically hindered phenols. In Examples (1-3, 10) polyisocyanates were prepared from tolylene diisocyanate, trimethylolpropane and (1) glycerol, (2) glycerol and 1,2,6-hexane triol, (3) glycerol and diethylene glycol, and (10) glycerol, diethylene glycol and 1,2,6-hexane triol. In the other examples these are made into foams by reaction with a polyether prepared from trimethylol propane and propylene oxide, a polymer of triethanolamine and propylene oxide, a polyether prepared from propylene oxide and sorbitol, a polyester of trimethylolpropane and adipic acid, a polymer of tolylene diamine and propylene oxide and other polymers derived from propylene oxide; b -chloroethyl phosphate; dibutyltin dilaurate, stannous octoate, triethylene diamine, dimethylcyclohexylamine, 4 - methylaminopyridine and dimethylbenzylamine lactate; silicone/oxyalkylene block copolymers, and glycerol; water and CCl3F; triethanolamine, propylene oxide/ethylene oxide copolymer and tolylene diisocyanate.