Patent GB-934790-A (GB)
Title: Preparation of improved polyurethane foams
IPC: C08G18/10
Filed: 1960-01-05
Abstract: A method of making a polyurethane prepolymer comprises either [A] (1) reacting a hydroxy terminated polyether polyol with organic polyisocyanate in an amount at least sufficient to provide a polyetherurethane having terminal isocyanate groups, (2) reacting said polyetherurethane with additional polyetherpolyol in an amount sufficient to provide a polyetherurethane of increased molecular weight having terminal hydroxy groups, (3) reacting the last mentioned polyetherurethane with additional organic polyisocyanate to provide a polyetherurethane of further increased molecular weight having terminal isocyanate groups and (4) optionally repeating stages (2) and (3) above, or [B] (1) reacting an organic polyisocyanate with a hydroxy terminated polyether polyol in an amount at least sufficient to provide a polyetherurethane having terminal hydroxyl groups, (2) reacting said polyetherurethane with additional organic polyisocyanate to provide a polyetherurethane of increased molecular weight having terminal isocyanate groups and, if desired, carrying out at least once the steps of (3) reacting the last-mentioned polyetherurethane with additional polyether polyol in an amount sufficient to provide a polyetherurethane of further increased molecular weight having terminal hydroxy groups and (4) reacting the last-mentioned polyetherurethane with additional organic polyisocyanate to provide a polyetherurethane of further increased molecular weight having terminal isocyanate groups.  The prepolymers are converted to polyurethane foams by reaction with water in the presence of a silicone oil, a catalyst and optionally a cross-linking agent containing a plurality of active hydrogens, specified catalysts being dibutyl amino alcohol, butyl diethanolamine, trihexylamine, tributylamine, tripropylamine, N-methyl morpholine, N-octyl morpholine, 4-pyridine propanol, 4-n-amyl-pyridine and cobalt and nickel naphthenate and linoleate; specified cross-linking agents being trimethylol propane, glycerol, 1:2:4-butane triol, hexanetriol, "Triol-230", N:N:N1:N1-tetrakis-(2-hydroxypropyl) ethylene diamine, hexamethylene tetramine and ethylene diamine.  Many silicone oils, polyether polyols and polyisocyanates are specified.  The examples describe the preparation of prepolymers from:-(1) polypropylene ether glycol, 2:4- and 2:6-toluylene diisocyanate and polytetramethylene ether glycol and (2) polypropylene ether glycol, m-phenylene diisocyanate and 2:4- and 2:6-toluylene diisocyanates; the prepolymers being converted to polyurethane foams by reaction with:- (1) water, a silicone oil and triethylamine and (2) polydimethyl siloxane, N-methyl morpholine and water.  Specification 908,012 is referred to.ALSO:A method of making a polyurethane foam comprises reacting with water on the presence of a silicone oil a catalyst and optionally a cross-linking agent containing a plurality of active hydrogens a prepolymer made either by [A] (1) reacting a hydroxy terminated polyether polyol with an organic polyisocyanate on an amount at least sufficient to provide a polyetherurethane having terminal isocyanate groups (2) reacting said polyetherurethane with additional polyetherpolyol in an amount sufficient to provide a polyetherurethane of increased molecular weight having terminal hydroxy groups (3) reacting the last mentioned polyetherurethane with additional organic polyisocyanate to provide a polyetherurethane of further increased molecular weight having terminal isocyanate groups and (4) optionally repeating stages (2) and (3) above, or [B] (1) reacting an organic polyisocyanate with a hydroxy terminated polyether polyol in an amount at least sufficient to provide a polyetherurethane having terminal hydroxyl groups (2) reacting said polyetherurethane with additional organic polyisocyanate to provide a polyetherurethane of increased molecular weight having terminal isocyanate groups and, if desired, carrying out at least once the steps of (3) reacting the last mentioned polyetherurethane with additional polyether polyol in an amount sufficient to provide a polyetherurethane of further increased molecular weight having terminal hydroxy groups and (4) reacting the last mentioned polyetherurethane with additional organic polyisocyanate to provide a polyurethane of further increased molecular weight having terminal isocyanate groups.  Many silicone oils, polyether polyols and polyisocyanates are specified.  Specified catalysts are dibutylamino alcohol, dibutyl diethanolamine, trihexylamine, tributyl amine, tripropylamine, N-methyl morpholine, N-octyl morpholine, 4-pyridine propanol, 4-n-amyl pyridine and coblat and nickel naphthenate and linoleate; specified crosslinking agents being trimethylol propane, glycerol, 1 : 2 : 4- butane triol, hexanetriol, "triol-230", N : N : N1 : N1-tetrakis (2-hydroxypropyl) ethylene diamine, hexamethylene tetramine and ethylene diamine.  In the examples (1) a propolymer made from polypropylene ether glycol, 2 : 4- and 2 : 6- toluylene diisocyanate and polytetramethylene ether glycol is reacted with water, a silicone oil and triethylamine and (2) a prepolymer made from polypropylene ether glycol m-phenylene diisocyanate and 2 : 4- and 2 : 6- toluylene diisocyanate is reacted with water, polydimethyl siloxane and N-methylmorpholine.  Specification 908,012 is referred to.