| 摘要 |
Polyurethanes are prepared by the reaction of an aromatic di-isocyanate with a polyhydroxyalkyl phosphate of the general formula <FORM:1022210/C3/1> in which R1 and R2 are each hydrogen or an alkyl radical which may carry a halogen substituent and n is at least 1 and the R1 and R2 may be the same or different. The polyhydroxy alkyl phosphates may be prepared by the reaction of phosphoric acid with an epoxide in a solvent, e.g. ethylene oxide, propylene oxide or epichlorhydrin in dioxane or tetrahydrofuran. In examples toluene di-isocyanate was reacted with (1) trihydroxyethyl phosphate (2) trihydroxypropyl phosphate (8) epichlorhydrin triester of M.W.465 in the presence of stannous octoate and silicone, and to the mixture was added sorbitol and trichlorofluoromethane to produce a rigid foam. Reference is directed by the Comptroller to Specification 922,198.ALSO:Polyhydroxyalkyl phosphates of general formula <FORM:1022210/C2/1> where R1 and R2 are hydrogen or an alkyl radical which may be substituted by a halogen atom, and n is at least 1, and the R1 and R2 groups may be same or different, may be prepared by reacting phosphoric acid with an epoxide, e.g. ethylene oxide, propylene oxide, epichlorhydrin in a common solvent, e.g. tetrahydrofuran or dioxane. The products may contain 6.5 to 8% by weight of phosphorus. Reference is directed by the Comptroller to Specification 922,198. |
