GB794061A - Manufacture of polyurethane materials - Google Patents

Abstract

A process for the manufacture of polyurethanes comprises reacting together a metal cyanate or mixture of metal cyanates, a polyhydric alcohol or mixture of polyhydric alcohols and a compound or compounds of the formula X-CH2-R-CH3-X wherein stands for -Cl, -Br, -I or -OSO2R1, where R1 stands for a monovalent hydrocarbon radical, and R stands for a divalent substituted or unsubstituted hydrocarbon residue. Reactants specified are sodium and potassium cyanates; ethylene glycol, hexamethylene glycol, decamethylene glycol, glycerol, pentaerythritol and hexantriol; ethylene dibromide, 1 : 4-dibromobutene-2, 1,4-dibromobutane, and compounds where R stands for a divalent aryl residue which may be further substituted, e.g. by methyl chlorine, such as 1 : 4-bis (chloromethyl) benzene and 1 : 4- or 1 : 5-bis(chloromethyl)-naphthalene. The reactants are heated together preferably in such quantities that there is at least one molecule of metal cyanate and at least one hydroxyl group present for each of the groups X. Suitable reaction media are dimethyl sulphoxide and organic amides derived from secondary amines of the type used in Specification 610,117, [Group IV (b)], e.g. dimethylformamide and N-isopropylphthalimidine. The products may be precipitated by cooling and, if necessary, adding a diluent such as water. Examples describe the preparation of polymeric products by heating together in dimethylformamide or dimethyl sulphoxide mixtures of (1) and (2) 1 : 4-bis(chloromethyl) benzene, sodium cyanate and ethylene glycol; (3) 4 : 6 - bis - (chloromethyl) - 1 : 3 - dimethylbenzene, sodium cyanate and ethylene glycol; (4) lead cyanate, 1 : 4-bis-(chloromethyl)-benzene and ethylene glycol; (5) 1 : 4-bis-(chloromethyl)-benzene, sodium cyanate and pentane-1 : 5-diol.