GB922860A - Improvements in and relating to polyurethane reaction products - Google Patents

Abstract

A method of preparing a polyurethane reaction product comprises reacting (a) an intermediate reaction product which is the product of reaction between an initial polymer containing terminal hydroxyl groups substituted with a monovalent metallic radical and an epoxy reagent containing in the molecule at least one labile halogen atom attached to a carbon atom, said product containing unreacted hydroxy groups, with (b) an organic compound having at least two -NCX radicals in its molecule, where X represents in the case of each radical an oxygen atom or a sulphur atom. The intermediate reaction product is usually prepared by reacting the initial polymer containing terminal hydroxyl groups substituted with monovalent metal radicals with the halogenated epoxy reagent and reacting the resultant reaction product with an initial polymer containing hydroxy groups. Epoxy compounds specified are epichlorhydrin, and epoxybutyl and epoxypentyl chlorides. Suitable initial polymers are polyethers, polythioethers, polyesteramides, polyesters and polyamides. The uncured polyurethane reaction product is usually produced as a syrup, premature setting of which can be prevented by adding an acid or acid-generating material. In a preferred method a sodium derivative of a polyalkylene ether polyol is reacted in toluene with sufficient halogenated epoxy compound to react with each -ONa group, so that the epoxy groups remain inactive. A further quantity of polyol is then reacted, addition taking place at the epoxy groups to give a product containing terminal and medial hydroxyl groups. Polyurethane reaction products prepared from a slight excess of -NCX compound can be converted to solid polyurethane elastomer by reaction with a cross-linking agent such as butane 1:4 diol. Foamed elastomers are prepared by using a polyurethane prepared from the hydroxy compound, a retarder such as benzoyl chloride, and a stoichiometric excess of -NCX compound. In examples (1) the sodium derivative of a polypropylene ether diol (M.W. 2000) is prepared and reacted in toluene with epichlorhydrin. The product is reacted with a further amount of the diol to give an intermediate reaction product, which is reacted with 2:4- and 2:6-tolylene diisocyanates to form a polyurethane reaction product. This is converted to a foam by stirring in a mixture of water, polydimethyl siloxane and N,N-dimethyl benzylamine; (2) the sodium derivatives of a polypropylene ether triol is employed in the first stage of a process similar to that of Example (1); (3) triethylene diamine and (4) a mixture of dibutyl tin dilaurate are used as catalysts in the foaming stage; (5) polypropylene ether triol is used in both steps of the preparation of the intermediate hydroxyl group containing reaction product, in a process similar to that of Example (1). The Provisional Specification refers also to the use as component (a) of a product obtained by reacting, instead of a halogenated epoxy compound, an organic compound containing in the molecule at least two halogen atoms attached to different carbon atoms and a polymer containing terminal hydroxyl groups of hydroxyl groups substituted with a monovalent metallic radical. Specified halogen compounds are tetrachloroquinone, chlorinated alkylbenzenes, trichlorethane and trichloropropane. In an example the sodium derivative of a polypropylene ether diol is reacted with trichloropropane. The product is reacted with a further amount of the sodium derivative. The product then obtained is reacted with naphthalene diisocyanate, butene 1:4-diol is stirred in, and the mixture is cast into moulds and heated.ALSO:A method of preparing a polyurethane reaction product comprises reacting (a) an intermediate reaction product which is the product of reaction between an initial polymer containing terminal hydroxyl groups substituted with a monovalent metallic radical and an epoxy reagent containing in the molecule at least one labile halogen atom attached to a carbon atom, said product containing unreacted hydroxy groups, with (b) an organic compound having at least two -NCX radicals in its molecule, where X represents in the case of each radical an oxygen atom or a sulphur atom. The intermediate reaction product is usually prepared by reacting the initial polymer containing terminal hydroxyl groups substituted with monovalent metal radicals with the halogenated epoxy reagent and reacting the resultant reaction product with an initial polymer containing hydroxy groups. Epoxy compounds specified are epichlorhydrin, and epoxybutyl and epoxypentyl chlorides. Suitable initial polymers are polyethers, polythioethers, polyesteramides, polyesters and polyamides. The uncured polyurethane reaction product is usually produced as a syrup, premature setting of which can be effected by adding an acid or acid-generating material. In a preferred method a sodium derivative of a polyalkylene ether polyol is reacted in toluene with sufficient halogenated epoxy compound to react with each -ONa group, so that the epoxy groups remain inactive. A further quantity of polyol is then reacted, addition taking place at the epoxy groups to give a product containing terminal and medial hydroxyl groups. Polyurethane reaction products prepared from a slight excess of -NCX compound can be converted to solid polyurethane elastomer by reaction with a cross-linking agent such as butane 1 : 4 diol. Foamed elastomers are prepared by using a poly-urethane prepared from the hydroxy compound, a retarder such as benzoyl chloride, and a stoichiometric excess of -NCX compound. In examples (1) the sodium derivative of a polypropylene ether diol (M.W. 2000) is prepared and reacted in toluene with epichlorhydrin. The product is reacted with a further amount of the diol to give an intermediate reaction product, which is reacted with 2 : 4-and 2 : 6- tolylene diisocyanates to form a polyurethane reaction product. This is converted to a foam by stirring in a mixture of water, polydimethyl siloxane and N, N-dimethyl benzylamine; (2) the sodium derivative of a polypropylene ether triol is employed in the first stage of a process similar to that of Example (1); (3) triethylene diamine and (4) a mixture dibutyl tin dilaurate are used as catalysts in the foaming stage; (5) polypropylene ether triol is used in both steps of the preparation of the intermediate hydroxyl group containing reaction product in a process similar to that of Example (1). The Provisional Specification describes also the use as component (a) of a reaction product of (instead of a halogenated epoxy compound) an organic compound containing in the molecule at least two halogen atoms attached to different carbonatoms and a polymer containing terminal hydroxyl groups or hydroxyl groups substituted with a monovalent metallic radical. Chloranil, tetrachloro-hydroquinone and chlorinated alkylbenzenes are specified halogen compounds.