TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The inorganic material is titanium dioxide or carbon black.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The second structural body further includes crosslinker, which is 2,5-dimethyl hexane, hydrogen peroxide, methyl hydrogen peroxide, and/or tert-butyl-2-ethylhexyl-carbonate. It further includes antioxidant, UV stabilizer, anti-hydrolysis agent, and/or flame retardant. The antioxidant is Irganox 1010 (RTM: pentaerythrityl-tetrakis(3-(3',5'-di-tert butyl-4-hydroxyphenyl)-propionate)). The UV stabilizer is Tinuvin 213 (RTM: benzotriazole). The anti-hydrolysis agent is Stabaxol I (RTM: N,N'-bis(2,6-diisopropylphenyl)carbodiimide). The flame retardant is triphenyl phosphate.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The first structural body containing a mixture of polyvinylidene fluoride, acrylic resins, and inorganic materials, comprises first and second temperature resistant layers and an electric insulating layer, which is adhered between the first and second temperature resistant layers; or first temperature resistant layers, heat adhering layer, and electric insulating layer, which is provided between the first temperature resistant layers and the heat adhering layer, where thickness of the second structural body is 300-600 mu m. The thicknesses of the first and second temperature resistant layers are respectively 5-50 mu m. The thickness of the electric insulating layer is 50-250 mu m. The thickness of the heat adhering layer is 50-100 mu m. The polyvinylidene fluoride, acrylic resins, and inorganic materials are at 20-80, 10-50, and 1-30 pts.wt., respectively. The acrylic resin is polymer or copolymer of methyl methacrylate, butyl methacrylate, acrylic ethyl ester, or butyl acrylic ester. It is polymethyl methacrylate. The electric insulating layer is polyethylene terephthalate, poly-2,6-ethylene naphthalate, or polyamide. The heat adhering layer is polyolefin or polymer of ethylene.