| 摘要 |
<p>The invention relates to weak alkyd resins used for producing high quality nitrocellulosic lacquers representing the product obtained from the reaction of 10 ... 30% bleached castor oil, 10 ... 30 % semi-siccative fatty acids obtained from soybean oil and/or sunflower oil, 5 ... 25% glycerine, 3 ... 18 % propylene glycol, 30 ... 50% phthalic anhydride, the mixture of bleached castor oil and fatty acids representing 20 ... 60 % of the reaction mixture, the percents being expressed by weight. The process comprises simultaneously carryingout the reactions of oil ester interchange and the polyesterification of the glycerides resulting from the ester interchange of the oil and fatty acids introduced by heating the raw materials in inert atmosphere at a temperature of 170 ... 175 C followed by keeping the reaction mass under reflux for 30 ... 60 min and then raising and maintaining the temperature at 210 ... 215 C for 30 ... 60 min, the synthesis being continued by progressively raising the temperature up to 225 ... 230 C and by the azeotropical removal of the reaction water.</p> |
