Novel hydrophobic polyurethane foams

Claim 1

A method for preparation of hydrophobic polyurethane foam which comprises, reacting the condensation prepolymer of polyisocyanate and essentially water-insoluble polyalkylene ether polyol or essentially water-insoluble polyalkylene ester polyol with large amounts of an aqueous reactant while in the presence of a catalyst and an emulsifying agent, maintaining an emulsion during foaming of the reactants, the water content of the aqueous reactant being about 35% to about 90% by weight based on the weight of the total composition to be foamed, the emulsifying agent being present in an amount of about 0.25 to about 10 parts per 100 parts of the condensation prepolymer and selected from the group consisting of fatty acyl sarcosine, fatty alkyl sarcosine, acyl-iminodiacetic acid, alkyl-iminodiacetic acid and condensates of ethylene oxide with a hydrophobic base, the catalyst being present in an amount of about 0.05% to about 3% by weight of the condensation prepolymer and selected from the group consisting of 3-morpholinopropionamide, 2-(diethylamino) acetamide, 2-methyl-3-(diethylamino)propionamide, triethylene diamine, N-lower alkyl morpholine, N,N,N'N'-tetramethylethylene diamine, N,N,N'N'-tetramethyl-1,3-butane-diamine, N,N-diethylcyclohexylamine trimethylamine formate, trimethylamine acetate, triethylamine formate, triethylamine acetate, N-methylmorpholine acetate, N-methylmorpholine citrate, trimethylamine ethylenediamine tetraacetate, trimethylamine imino-triacetate, stannous octoate, stannous oleate, dibutyltin dilaurate, dibutyltin and di-2-ethylhexoate, and the said polyalkylene ether polyol or polyalkylene ester polyol having a weight average molecular weight of about 200 to about 20,000 and a hydroxyl functionality ranging from about 2 to about 8 hydroxyl groups per molecule, the ratio in the condensation prepolymer of isocyanate groups in the polyisocyanate to the hydroxyl groups being between about 1 to about 4 isocyanate to hydroxyl molar ratio, and recovering a hydrophobic polyurethane foam.

Claim 2

A method for preparation of hydrophobic polyurethane foam which comprises, reacting the condensation prepolymer of polyisocyanate and essentially water-insoluble polyalkylene ether polyol or essentially water-insoluble polyalkylene ester polyol with large amounts of an aqueous reactant while in the presence of a catalyst and an emulsifying agent, maintaining an emulsion during foaming of the reactants, the water content of the aqueous reactant being about 35% to about 90% by weight based on the weight of the total composition to be foamed, the emulsifying agent being present in an amount of about 0.25 to about 10 parts per 100 parts of the condensation prepolymer and selected from the group consisting of fatty acyl sarcosine, fatty alkyl sarcosine, acyl-iminodiacetic acid, alkyl-iminodiacetic acid and condensates of ethylene oxide with a hydrophobic base, the catalyst being present in an amount of about 0.05% to about 3% by weight of the condensation prepolymer and selected from the group consisting of 3-morpholinopropionamide, 2-(diethylamino) acetamide, 2-methyl-3-(diethylamino)propionamide, triethylene diamine, N-lower alkyl morpholine, N,N,N'N'-tetramethylethylene diamine, N,N,N'N'-tetramethyl-1,3-butane-diamine, N,N-diethylcyclohexylamine trimethylamine formate, trimethylamine acetate, triethylamine formate, triethylamine acetate, N-methylmorpholine acetate, N-methylmorpholine citrate, trimethylamine ethylenediamine tetraacetate, trimethylamine imino-triacetate, stannous octoate, stannous oleate, dibutyltin dilaurate, dibutyltin and di-2-ethylhexoate, and the said polyalkylene ether polyol or polyalkylene ester polyol having a weight average molecular weight of about 200 to about 20,000 and a hydroxyl functionality ranging from about 2 to about 8 hydroxyl groups per molecule, the ratio in the condensation prepolymer of isocyanate groups in the polyisocyanate to the hydroxyl groups being between about 1 to about 4 isocyanate to hydroxyl molar ratio, and recovering a hydrophobic polyurethane foam.