| 摘要 |
PURPOSE:To obtain a lowly viscous and suitably castable composition for the production of a polyurethane elastomer by mixing a specified isocyanate- terminated urethane prepolymer with an aromatic polyamine, a curing agent such as a polyfunctional (meth)acrylate, and a polymerization initiator. CONSTITUTION:A casting composition for the production of a polyurethane elastomer is prepared by mixing an isocyanate-terminated urethane prepolymer (A) [prepared by reacting a high-molecular polyol with an unsaturated low- molecular polyol (e.g. 1,4-butanediol) and a polyisocyanate in an NCO to OH ratio of 1.3-3.0] with a curing agent (B) (aromatic polyamine and/or low- molecular polyol), a polyfunctional (meth)acrylate (C), and a polymerization initiator (D). The mixing ratio among the respective components is such that the ratio of the NCO groups of component A to the active hydrogen atoms of component B is 0.9-1.3, desirably 1.0-1.2, component C is used in an amount of 5-50 pts.wt. per 100 pts.wt. component A, and component D is used in an amount of 0.5-10 pts.wt., desirably 1-5 pts.wt. per 100 pts.wt total of components A and B. |
