To provide a painted metal plate with high solar heat reflecting properties optimum as a building external facing material such as a lightweight roofing material with excellent heat insulating properties, colored in any color and manufacturable at low cost with good productivity.
One face, receiving solar radiation, of a metal base (e.g. a plated steel plate) is provided with a paint film containing 2-70 mass% pigment whose solar heat reflectivity RE/NIR in a wavelength range of 0.8-2.1 μm is 10% or more, and RE/NIR of the painted face is set to 20% or more. In the case the solar heat transmissivity TE/NIR in a wavelength range of 0.8-2.1 μm of the paint film is as high as 20% or more, a metal base (e.g. an Al-based plated steel plate) with high RE/NIR of 40% or more is used to utilize reflection also from the base. It is preferable to form the back face side of a low emissivity face with the emissivity of 70% or less, and the paint film containing 0.05-1.5 g/m2 of scale-like aluminum pigment is preferable. When a contact angle to water on the surface of the solar radiation receiving face is set not more than 60° or not less than 90°, stain resistance is excellent, and a lowering of solar heat reflecting properties caused by stain is prevented.
IKISHIMA KENJI
MATSUO SACHIO
TOMOHIRO MINORU
SUMITOMO METAL STEEL PROD