GB892776A - Improvements in or relating to the manufacture of foamed polymeric materials - Google Patents

Abstract

A process for the manufacture of rigid or semirigid foamed polymeric products comprises reacting 100 parts by weight of a monomeric organic polyisocyanate with between 1 and 30 parts by weight of water in the presence of between 5 and 200 parts by weight of a non-ionic surface-active agent that is at least partially miscible with water and between 0,1 and 30 parts by weight of a catalyst for the reactions of organic polyisocyanates. Preferably the reaction mixture also contains 5 to 30 parts by weight of a compound containing two or more isocyanatereactive groups, such as trimethylopropane, ethyl cellulose, and hydroxyl-ended polyesters and polyethers. Suitable catalysts are tertiary amines and their salts; complexes of a b -diketone with manganese, thorium, titanium or zirconium; dibutyl tin dilaurate; basic inorganic compounds and basic alkali metal salts of weak acids. Surface-active agents specified are reaction products of ethylene oxide with aliphatic alcohols containing 12 to 22 carbon atoms per molecule or with alkyl phenols containing 6 to 12 carbon atoms in the alkyl groups. Pigments, flameproofing agents and fillers may be incorporated in the products. In typical examples foamed products are prepared from mixtures of (5) tri-b -chloroethyl phosphate, tris-2:4-pentane diono manganese III, water, an octyl-cresol/ethylene oxide reaction product and a diphenylmethane diisocyanate composition prepared from a crude diamine containing some polyamine; (10) 25 parts of a polyester (from pentaerythritol, 1:3-butylene glycol, adipic acid and phthalic anhydride), 7,5 parts of ethylene oxide/octyl cresol condensate, 10 parts water, 7,5 parts potassium acetate and 120 parts of the diphenylmethane diisocyanate composition as before. The foams are useful for packaging and as thermal insulation.ALSO:A process for the manufacture of rigid or semi-rigid foamed polymeric products comprises reacting 100 parts by weight of a monomeric organic polyisocyanate with between 1 and 30 parts by weight of water in the presence of between 5 and 200 parts by weight of a nonionic surface-active agent that is at least partially miscible with water and between 0,1 and 30 parts by weight of a catalyst for the reactions of organic polyisocyanates. Preferably the reaction mixture also contains 5 to 30 parts by weight of a compound containing two or more isocyanate-reactive groups, such as trimethylolpropane, ethyl cellulose and hydroxyl-ended polyesters and poly-ethers. Suitable catalysts are tertiary amines and their salts; complexes of a b -diketone with manganese, thorium, titanium or zirconium; dibutyl tin dilaurate; basic inorganic compounds as basic alkali metal salts of weak acids. Surface active agents specified are reaction products of ethylene oxide with aliphatic alcohols containing 12 to 22 carbon atoms per molecule or with alkyl phenols containing 6 to 12 carbon atoms in the alkyl groups. Pigments, flame-proofing agents and fillers may be incorporated in the products. In typical examples foamed products are prepared from mixtures of (5) tri-b -chloroethyl phosphate, tris-2 : 4-pentane diono manganese III, water, an octylcresol/ethylene oxide reaction product, and a diphenylmethane diisocyanate composition prepared from a crude diamine containing some polyamine; (10) 25 parts of a polyester (from pentaerythritol, 1 : 3-butylene glycol, adipic acid and phthalic anhydride), 7,5 parts ethylene oxide/octyl cresol condensate, 10 parts water, 7,5 parts potassium acetate and 120 parts of the diphenylmethane diisocyanate composition. The foams are useful for packaging and as thermal insulation.