| 摘要 |
PURPOSE:To easily manufacture a lightweight sandwich board excellent in mechanical properties by a method wherein a reaction liquid, which contains monomer containing norbornane unit and metathesis catalyst, is poured between surface members by reaction injection molding system so as to polymerize it. CONSTITUTION:Norbornane unit containing monomer employed is 2-norbornane, 5-methyl-2-norbornane, 5,6-dimethyl-norbornane, 5-ethyl-2-norbornane, dicyclo pentadiene, methylcyclododecene, dihydrodicyclopentadiene, methyl tetracyclododecene or the like and their mixture. These monomers are inverted into polymers by the publicly known ring opening polymerization. As for the catalyst used for said polymerization, the publicly known metathesis polymeriza tion catalyst is employed. Because the viscosity of the used reaction liquid is low, the object can be poured under a pressure as low as only 10kg/cm<2> between surface members and at the same time is rapidly polymerized between the surface members. |
