| 摘要 |
PURPOSE:To produce a corrosion preventing effect on a metallic material by adding a water-soluble high-molecular compound which is relatively liable to gel and an anticorrosive to a cooling water system and by adjusting the pH to a specified value or above. CONSTITUTION:A water-soluble high-molecular compound which is relatively liable to gel and an anticorrosive are added to a cooling water system in a petroleum refining plant, a chemical industry plant, an air conditioning plant or the like, and the pH is adjusted to >=6.5. The amount of the high molecular compound added is 1-100mg/l, and the amount of the anticorrosive is 0.5-500mg/l. A polymer of acrylic acid or itaconic acid having 500-200,000, especially 1,000- 10,000mol.wt. is used as the water-soluble high molecular compound. Nitrous acid, phosphoric acid, phosphonic acid, a multivalent metal, carboxylic acid or a salt thereof is used as the anticorrosive. |
