| 摘要 |
PURPOSE:To obtain the titled coating film of high-efficiency, by using a carboxylic acid amide copolymerizate, a specific oxide or the like, and a coating of solvent base for ingredients of composition by determining the ratio of solid content in the coating at a specific ratio, and by coating the above-mentioned coating composition on a solar heat collecting surface, with an amino modified silicon resin or the like being added to it. CONSTITUTION:A carboxylic acid amide copolymerizate, an oxide or a compound oxide composed of more than one element selected from a group of Fe, Mn, Cu, Cr, Co, and Ni, and a coating of solvent base of which chief ingredient is low molecular weight 4- fluoride ethylene resin, are used to form the surface of a solar heat collector, which is a coating film selectively absorbing solar heat. The ratio of solid content in the coating is determined to be below 10wt% at the weight ratio, and a coating composition is heated to be hardened, after it is coated on the heat collecting surface, with an amino modified silicon resin or a carboxyl modified silicon resin being added to it. By this method, any defect such as a pin hole will not be produced in the film, and with a high film-forming workability, the titled coating film of superior selective absorption characteristic can be obtained. |
