Patent GB-862231-A (GB)
Title: Polyurethane foams and method of preparation thereof
IPC: C08J9/00
Filed: 1958-03-17
Abstract: In a method for the manufacture of polyurethane foam plastics by reaction of organic polyisocyanates with blends of linear polyand high molecular weight polyglycols in the presence of water and a wetting agent, the reaction is effected in the presence of a pyrrolidone catalyst to provide a foam having improved hydrophilic properties.  Suitable catalysts are 2-pyrrolidone, N-methylpyrrolidone, or vinylpyrrolidone.  The polyglycols should have a molecular weight between about 600 and 6000 and should be used in the proportion of 0.6 to 1.5 parts by weight per part of polyester.  Suitable polyesters are those obtained from such polyhydric alcohols and aminoalcohols as glycol, diethylene glycol, ethanolamines and other aminoalkanols and from such acids as oxalic, adipic, sebacic, 6-amino - caproic, phthalic, isophthalic, terephthalic, malonic, succinic, maleic, fumaric, itaconic and dimer acids.  (The "dimer" acids are dimers and trimers of unsaturated C11 fatty acids). Tolylene, phenylene, 4-chloro-1,3 - phenylene, 1,5 - naphthalene, 3,31 - dimethoxy - 4,41 - biphenylene, 3,31 - diphenyl4,41-biphenylene, and alkylene diisocyanates, methylene - bis - (4 - phenyl - isocyanate) and triphenyl-methane triisocyanate are specified.  As wetting agents there are mentioned mixtures of polyalcohol carboxylic acid esters, sodium salts of organic sulphonates, and mixtures of alkylaryl polyether alcohols and organic sulphonates.  The polyester, polyglycol and diisocyanate may first be reacted to form a prepolymer, the NCO content of which is adjusted to e.g. 5 to 10% by weight of the mixture, and foaming may then be effected by adding an aqueous mixture of wetting agents and catalysts.  The foams have an open-celled structure and are useful as wash-cloths, coasters under drinking glasses, sweatbands for hats, flower pot pads, matrices for growing plants from seeds foamed in place within the mass and as packing and insulating material.ALSO:In a method for the manufacture of polyurethane foam plastics by reaction of organic polyisocyanates with blends of linear polyesters and high molecular weight polyglycols in the presence of water and a wetting agent, the reaction is effected in the presence of a pyrrolidone catalyst to provide a foam having improved hydrophilic properties.  Suitable catalysts are 2- pyrrolidone, N- methyl-pyrrolidone, or vinylpyrrolidone.  The polyglycols should have a molecular weight between about 600 and 6000 and should be used in the proportion of 0,6 to 1,5 parts by weight per part of polyester. Suitable polyesters are those obtained from such polyhydric alcohols and amino-alcohols as glycol, diethylene glycol, ethanolamines and other aminoalkanols and from such acids as oxalic, adipic, sebacic, 6- amino-caproic, phthalic, isophthalic, terephthalic, malonic, succinic, maleic, fumaric, itaconic and dimer acids.  (The "dimer" acids are dimers and trimers of unsaturated C18 fatty acids). Tolylene, phenylene, 4- chloro-1, 3- phenylene, 1, 5- naphthalene, 3, 3-dimethoxy-4, 41- biphenylene, 3, 31- diphenyl-4, 41 biphenylene, and alkylene diisocyanates, methylene-bis-(4- phenyl-isocyanate) and triphenyl-methane triisocyanate are specified.  As wetting agents there are mentioned mixtures of polyalcohol carboxylic acid esters, sodium salts of organic sulphonates, and mixtures of alkylaryl polyether alcohols and organic sulphonates.  The polyester, polyglycol and diisocyanate may first be reacted to form a prepolymer, the NCO content of which is adjusted to e.g. 5% to 10% by weight of the mixture, and foaming may then be effected by adding an aqueous mixture of wetting agents and catalysts.  The foams have an open-celled structure and are useful as washcloths, coasters under drinking glasses, sweat-bands for hats, flower pot pads, matrices for growing plants from seeds foamed in place within the mass and as packing and insulating material.