| 摘要 |
PURPOSE:To improve durability while preventing the lowering of an absorption index by forming a black film consisting of a black opaque heat-resistant resin onto a blackened film as a solar-heat selective absorbing film element formed to the surface of a metallic base body within a range of 0.1-0.8mum thickness. CONSTITUTION:The aluminum plate of the purity of JIS A1030 is degreased by a degreaser such as a non-etching type degreaser, and DC-electrolysed for 10min by 15V DC in an aqueous solution of 100g/l phosphoric acid, and an anodic oxidation film of 0.6mum thickness is formed to the surface. The film is AC electrolysed for 3min by 15V AC in an aqueous solution of 30g/l nickel sulfate and 30g/l boric acid to blacken the film. The blackened film is brought to 1mum thickness or less. The black opaque film is formed onto the black film within the range of 0.1-0.8mum thickness. The comparison of the selective absorption performance of the heat collecting plates in which the films of 0.3mum, 0.5mum and 1.0mum thickness are formed by a polyester denatured silicon resin and an acrylic resin is shown in the table. |
