Patent GB-870119-A (GB)
Title: Polyalkylene ether glycol-diisocyanate cellular elastomers
IPC: C08J9/38
Filed: 1957-09-18
Abstract: The invention comprises a process for the production of foamed polyurethane material by conversion into the foamed condition of the reaction product of an organic polyisocyanate and a polyalkylene ether glycol of molecular weight from 750 to 10,000 with the aid of a tertiary amine catalyst which is a b -hydroxy tertiary alkylamine or an N-hydrocarbon substituted morpholine, the resulting foam being subjected to wringing to break the cells thereof and to remove any entrapped gas.  The reaction between the polyisocyanate and the glycol may be conducted initially in the absence of the catalyst to give a liquid prepolymer which is then further reacted in the presence of the catalyst to produce the foamed product.  A cross-linking agent having at least three active hydrogen atoms per molecule such as trimethylol propane, glycerol, 1, 24-butanetriol, hexanetriol, the betaethanol ether of 2-methyl-2-methylol-4-methyl-5-hydroxy pentane, N, N, N1, N1-tetrakis (2-hydroxypropyl) ethylene diamine, or polyamines such as hexamethylene tetramine and ethylene diamine also may be present in the reaction mixture.  As catalysts these are specified dibutyl amino alcohol, butyl diethanolamine and N-methyl or N-octyl-morpholine, and these may be mixed with tertiary alkylamines.  Different polyglycols or polyisocyanates may be used in admixture or may be reacted successively in separate steps in the preparation of the prepolymer. A highly viscous prepolymer from near equal amounts of glycol and polyisocyanate may be used in admixture with a low viscosity prepolymer obtained using excess of one of the reactants.  In Examples (1) a prepolymer from a mixed polyethylene polypropylene glycol (of average molecular weight 2500) and 2, 4- and 2, 6-toluene diisocyanates is foamed by adding silicone oil and then mixing with N, N, N1, N1-tetraki (2-hydroxypropyl) ethylene diamine, water and N-methyl morpholine.  The foamed product is then passed through squeeze rolls at such a spacing as to rupture the cell walls without tearing the sponge.  In generally similar examples there are employed (2) a prepolymer from a mixed polyethylene polypropylene ether of molecular weight 3700; (3) a prepolymer from polytetramethylene ether glycol and 2, 4-toluene diisocyanate and trimethylol propane, water, a nonylphenoxy polyoxyethylene ethanol, dioctyl sodium sulphosuccinate, N-methyl morpholine and silicone oil; (4) a polypropylene ether glycol-/2, 4-toluene diisocyanate prepolymer, water, N-methyl-morpholine, silicone oil and 1, 2, 4-butanetriol.ALSO:The invention comprises a process for the production of foamed polyurethane material by conversion into the foamed condition of the reaction product of an organic polyisocyanate and a polyalkylene ether glycol of molecular weight from 750 to 10,000 with the aid of a tertiary amine catalyst which is a b -hydroxy tertiary alkylamine or an N-hydrocarbon substituted morpholine, the resulting foam being subjected to wringing to break the cells thereof, and to remove any entrapped gas.  The reaction between the polyisocyanate and the glycol may be conducted initially in the absence of the catalyst to give a liquid prepolymer which is then further reacted in the presence of the catalyst to produce the foamed product.  A cross -linking agent having at least three active hydrogen atoms per molecule such as trimethylol propane, glycerol, 1,24-butanetriol, hexanetriol, the beta-ethanol ether of 2-methyl-2-methylol-4- methyl -5- hydroxy pentane, N,N,N1,N1-tetrakis (2-hydroxypropyl) ethylene diamine, or polyamines such as hexamethylene tetramine and ethylene diamine also may be present in the reaction mixture.  As catalysts these are specified dibutyl amino alcohol, butyl diethanolamine and N-methyl or N-octyl-morpholine, and these may be mixed with tertiary alkylamines.  Different polyglycols or polyisocyanates may be used in admixture or may be reacted successively in separate steps in the preparation of the prepolymer. A highly viscous prepolymer from near equal amounts of glycol and polyisocyanate may be used in admixture with a low viscosity prepolymer obtained using excess of one of the reactants.  In Examples (1) a prepolymer from a mixed polyethylene polypropylene glycol (of average molecular weight 2500) and 2,4- and 2,6-toluene diisocyanates is foamed by adding silicone oil and then mixing N,N,N1,N1-tetrakis (2-hydroxy-propyl) ethylene diamine, water and N-methyl morpholine.  The foamed product is then passed through squeeze rolls at such a spacing as to rupture the cell walls without tearing the sponge.  In generally similar examples there are employed (2) a prepolymer from a mixed polyethylene polypropylene ether of molecular weight 3700; (3) a prepolymer from polytetramethylene ether glycol and 2,4,-toluene diisocyanate and trimethylol propane, water, a nonylphenoxypolyoxyethylene ethanol, dioctyl sodium sulphosuccinate, N-methyl morpholine and silicone oil; (4) a polypropylene ether glycol 2,4-toluene diisocyanate prepolymer, water, N-methyl morpholine, silicone oil and 1,2,4-butanetriol.