| 摘要 |
PURPOSE:To realize an improvement particularly in minimizing the corrosiveness of an amine-free composition to aluminum, by incorporating a phosphoric acid compound, an aromatic polybasic acid, a magnesium compound, and a corrosion inhibitor into an anti-freeze comprising a glycol and water, and adjusting the pH of the mixture to a specified value. CONSTITUTION:This anti-freeze is prepared by incorporating a phosphoric acid compound, an aromatic polybasic acid, a magnesium compound, and a corrosion inhibitor into an anti-freeze comprising a glycol and water, and has a pH of 6.5-9.0. As a phosphoric acid compound, phosphoric acid or its salt is used in an amount of about 0.1-5.0wt.% based on the stock solution of the anti-freeze. As an aromatic polybasic acid, a benzenepolycarboxylic compound, such as phthalic or trimellitic acid, can be used in an amount of about 0.05-1.0wt.% based on the stock solution of the anti-freeze. A magnesium compound (e.g., magnesium oxide) is used in an amount of about 0.001-0.08wt.%. And a corrosion inhibitor (e.g., a nitrate) is used in an amount of about 0.05-10.0wt.% each based on the stock solution of the anti-freeze. |
