| 摘要 |
1,141,708. Polyurethanes. ALLIED CHEMICAL CORP. 18 Feb., 1966 [19 Feb., 1965], No. 7318/66. Heading C3R. Curable polyurethane compositions comprise a urethane prepolymer containing free isocyanate groups, a chain extender composed of a major proportion by wt. of an aryl diamine and an amount of an organotin compound, e.g. from 0.15 to 0.40% by wt., which is effective to provide a polyurethane composition with extended pot-life. The composition may comprise 5-25% by wt. of the chain-extender which may contain a minor proportion by wt. of a glycol or aminoalkanol together with the aryl diamine. In examples, the pot-life of a prepolymer of ethylene-propylene adipate with toluene diisocyanate, chain extended with 4,4<SP>1 </SP>- methylene - bis - (2 - chloroaniline) and 1,4-butane diol is extended from 75 sees. to up to 180 sees. using varying quantities of stannous octoate and dibutyltin dilaurate. |
