Patent GB-908608-A (GB)
IPC: C08G18/10
Filed: 1960-09-06
Abstract: A process for the preparation of cellular polyurethane plastics comprises (i) reacting a polyhydric polyalkylene ether containing at least three alcoholic hydroxyl groups with an organic polyisocyanate containing at least three free -NCO groups, the amount of the polyisocyanate being only sufficient to react with less than 30% of the hydroxyl groups of the polyhydric polyalkylene ether to form an initial adduct and (ii) reacting this adduct with an organic polyisocyanate and water, the amount of polyisocyanate used in step (ii) being in excess of that necessary to react with all the free hydroxyl groups of the initial adduct.  The polyhydric ethers may be used in conjunction with polyalkylene glycols.  The polyhydric ethers can be prepared from an alkylene oxide, such as ethylene, propylene, butylene or styrene oxide or epichlorhydrin and an amino alcohol, polyamine or polyalcohol.  The glycols can be formed from such oxides per se, or together with divalent amines, amino alcohols or glycols. The triisocyanates listed include reaction products of triols with diisocyanates, p,p1,p11-tri-(isocyanatophenyl) phosphate and biuret polyisocyanates such as those described in Specification 876,503. The products of the first stage, before foaming, can be dissolved in toluene, benzene, o-dichlorobenzene, chlorobenzene, chloroform or gasoline.  In the second stage an organic diisocyanate can be used instead of or in addition to triisocyanates.  Emulsifiers, including the silicones described in Specification 804,369 can be added in the foaming step. Paraffin oils, fillers, flame-proofing agents and plasticizers can also be added.  As catalysts there can be used tertiary amines, alkali metal hydroxides, carbonates, phenolates and alcoholates and organotin compounds.  Examples describe the preparation of foams from (2) propoxylated trimethylol propane which has been reacted with 10 equivalent per cent of p,p1,p11-triisocyanato triphenyl phosphate, toluylene-2,4 and 2,6-diisocyanates, water, silicone-alkylene oxide copolymer, endoethylene piperazine and Sn (II)-ethylhexoate; (5) a propylene oxide addition product of glycerine which has been reacted with a biuret polyisocyanate (a reaction product of hexamethylene diisocyanate and salicylic acid).  Specification 769,682 also is referredALSO:A process for the preparation of cellular polyurethane plastics comprises (i) reacting a polyhydric polyalkylene ether containing at least three alcoholic hydroxyl groups with an organic polyisocyanate containing at least three free-NCO groups, the amount of the polyisocyanate being only sufficient to react with less than 30% of the hydroxyl groups of the polyhydric polyalkylene ether to form an initial adduct and (ii) reacting this adduct with an organic polyisocyanate and water, the amount of polyisocyanate used in step (ii) being in excess of that necessary to react with all the free hydroxyl groups of the initial adduct.  The polyhydric ethers may be used in conjunction with polyalkylene glycols.  The polyhydric ethers can be prepared from an alkylene oxide, such as ethylene, propylene, butylene or styrene oxide or epichlorhydrin and an aminoalcohol, polyamine or polyalcohol.  The glycols can be prepared from such oxides per se, or together with divalent amines, aminoalcohols, or glycols.  The triisocyanates listed include reaction products of triols with diisocyanates, p, p1, p11-tri-(isocyanatophenyl) phosphate and biuret polyisocyanates such as those described in Specification 876,503.  The products of the first stage, before foaming, can be dissolved in toluene, benzene, o-dichlorobenzene, chlorobenzene, chloroform or gasoline.  In the second stage an organic diisocyanate can be used instead of or in addition to triisocyanates.  Emulsifiers, including the silicones described in Specification 804,369 can be added in the foaming step.  Paraffin oils, fillers, flameproofing agents and plasticizers can also be added.  As catalysts there can be used tertiary amines, alkali metal hydroxides, carbonates, phenolates and alcoholates and organo-tin compounds.  Examples describe the preparation of foams from (2) propoxylated trimethylol propane which has been reacted with 10 equivalent per cent of p, p1, p11-triisocyanato triphenyl phosphate, toluylene-2, 4 and 2, 6-diisocyanates, water, silicone-alkylene oxide copolymer, endoethylene piperazine and Sn(II)-ethylhexoate; (5) a propylene oxide addition product of glycerine which has been reacted with a biuret polyisocyanate (a reaction product of hexamethylene diisocyanate and salicyclic acid).  Specification 769,682 also is referred to.