GB902548A - Improvements in or relating to the manufacture of foamed polyurethanes - Google Patents

Abstract

Foamed polyurethanes are obtained by reacting hydroxyl group-containing polyethers containing at least two isocyanate reactive groups per molecule with organic polyisocyanates in the presence of (1) a gas-forming agent such as water or a non-isocyanate reactive organic liquid with a boiling point not exceeding 75 DEG C. and (2) a pre-formed reaction product of a polyester, polyesteramide or polyether containing at least two isocyanate reactive groups per molecule with an organic polyisocyanate in an amount such that at least one isocyanate group is used for every two isocyanate reactive groups in the polyester polyesteramide or polyether. Numerous polyisocyanates and reactants for preparing the polyesters, polyesteramides and polyethers are specified; the polyisocyanates and polyethers may be used to prepare the pre-polymer as well as taking part in the main reaction. Organic gas-forming agents specified include acetone, methylene dichloride and chlorofluoro- and bromofluoro-alkanes. Addition constituents of the main reaction mixture include catalysts dimethylbenzylamine, dimethylcyclohexylamine, triethylene diamine, and salts of these amines with lactic or oxalic acid, manganese and iron acetylacetonates, dibutyl tin dilaurate and stannous octoate surface-active agents oxyethylated phenols such as octyl phenol, oxyethylated fatty alcohols such as cetyl alcohol, fatty acid salts such as diethylamine oleate, sulphated hydrocarbon chain-containing substances such as sulphated methyl oleate and silicone oils such as polydimethylsiloxane and polyoxyalkylene-polysiloxane block copolymers flame proofing agents trichloroethyl phosphate and antimony oxide. In the examples, the polyurethane foam is prepared from reaction mixtures containing (1) oxypropylated sucrose, water, a condensate of an alkyl cresol with ethylene oxide, dibutyl tin dilaurate, dimethylcyclohexylamine, 4:41-diisocyanato-diphenylmethane and (2) oxypropylated glycerol, water, a condensate of an alkyl cresol with ethylene oxide, b -trichloroethyl phosphate, 4:41-diisocyanato-diphenylmethane, and a prepolymer prepared from a polypropylene glycol and a mixture of 2:4- and 2:6-tolylene diisocyanates.ALSO:Foamed polyurethanes are obtained by reacting hydroxyl groupcontaining polyethers containing at least two isocyanate reactive groups per molecule with organic polyisocyanates in the presence of (1) a gas-forming agent such as water or a non-isocyanate reactive organic liquid with a boiling point not exceeding 75 DEG C. and (2) a pre-formed reaction product of a polyester, polyesteramide or polyether containing at least two isocyanate reactive groups per molecule with an organic polyisocyanate in an amount such that at least one isocyanate group is used for every two isocyanate reactive groups in the polyester, polyesteramide or polyether. Numerous polyisocyanates and reactants for preparing the polyesters, polyesteramides and polyethers are specified; the polyisocyanates and polyethers may be used to prepare the pre-polymer as well as taking part in the main reaction. Organic gas-forming agents specified include acetone, methylene dichloride and chlorofluoro- and bromofluoro-alkanes. Addition constituents of the main reaction mixture include catalysts dimethylbenzylamine, dimethylcyclohexylamine, triethylene diamine and salts of these amines with lactic or oxalic acid, manganese and iron acetylacetonates, dibutyl tindilaurate and stannous octoate surface active agents: oxyethylated phenols such as octyl phenol, oxyethylated fatty alcohols such as cetyl alcohol, fatty acid salts such as diethylamine oleate, sulphated hydro-carbon chain-containing substances such as sulphated methyl oleate and silicone oils such as polydimethylsiloxane and polyoxyalkylene-polysiloxane block copolymers flame proofing agents: trichloroethyl phosphate and antimony oxide. In the examples, the polyurethane foam is prepared from reaction mixtures containing (1) oxypropylated sucrose, water, a condensate of an alkyl cresol with ethylene oxide, di-butyl tindilaurate, dimethylcyclohexylamine, 4 : 41-diisocyanatodiphenylmethane and a prepolymer prepared from oxypropylated glycerol and 4 : 41-diisocyanato-diphenylmethane and (2) oxypropylated glycerol, water, a condensate of an alkylcresol with ethylene oxide, b -trichloroethyl phosphate, 4 : 41-diisocyanate-diphenylmethane, and a prepolymer prepared from a polypropylene glycol and a mixture of 2 : 4-and 2 : 6- tolylene diisocyanates.