| 摘要 |
PROBLEM TO BE SOLVED: To produce a resin foam which is highly useful as an insulator for an electric circuit substrate and exhibits low dielectric properties, a low dielectric loss, high strengths, a high heat resistance, good adhesion to other materials, and a good platability. SOLUTION: A substantially syndiotactic polystyrene foam (an SPS foam) having a closed-cell structure, a cell density of about 10<9> -10<15> per cm<3> , and an average cell size of 0.1-10μm can be produced by impregnating a synciotactic polystyrene resin (an SPS resin) with an inert gas under the atmospheric pressure or higher and rapidly decreasing the pressure to foam the SPS resin. An electric circuit substrate is obtd. by molding the foam and integrally bonding a conductive substance to at least one side of the resultant molding. |
