| 摘要 |
An organic polyisocyanate composition consists of 1-40% by weight of m-phenylene diisocyanate and 99-60% by weight of a toluene diisocyanate or a mixture of two or more isomeric toluene diisocyanates liquid at a temperature of 22 DEG C. The eutectic composition corresponding to 26% by weight of m-phenylene diisocyanate is preferred for convenience in handling. The compositions may be made by mixing m-phenylene diisocyanate, either as a solid or as a liquid, with toluene diisocyanate at room temperature in a dry atmosphere. The order of addition is not critical. Conventional means of agitation may be employed. Specifications 790,527, 796,041 and 797,965 are referred to.ALSO:A polyurethane is made by the reaction of a composition consisting of 1-40% by weight of m-phenylene diisocyanate and 99-60% by weight of a toluene diisocyanate or a mixture of two or more isomeric toluene diisocyanates liquid at a temperature of 22 DEG C., with a difunctional organic compound in which the functional groups will react with isocyanate groups, such as a polyol and in particular a polyether glycol, to form a polyurethane. They may be used to make cellular polyurethane articles according to the procedure in Specifications 797,965 and 790,527. In examples, polyurethanes are made from the diisocyanate composition and (a) polypropylene ether glycol and stannous octoate; (b) polypropylene ether triol, polydimethyl-siloxane-polyalkylene ether block copolymer, stannous octoate, triethylene diamine and water, the resulting fluid being allowed to foam. Specification 796,041 also is referred to. |
