| 摘要 |
The aim of the invention is to prepare a water-soluble alkyd type paint that dries in the air and can be dissolved in and diluted with water. The free carboxyl groups in the alkyd resin are neutralized with ammonia, an amine or a similar compound to form a water-soluble ammonium salt. The neutralization is carried out in two steps. The first step involves the addition of ammonia, an amine or a similar compound in an amount that is only enough for partial neutralization, giving a limited amount of the water-soluble ammonium salt. The second step involves the addition of a water-soluble alkali, such as sodium tetraborate, in an amount that ensures complete neutralization and solubilization. The air drying of the paint leaves behind the ammonium salt (soap) in the film and confers on the latter the required water resistance. The evolution of ammonia or an amine- containing vapour can be avoided here during the drying process.
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