反应详情

温度

60 °C

Into a four-neck flask equipped with a thermometer, a stirrer, and a nitrogen introducing tube charged were 10.711 g (0.0364 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 7.289 g (0.0364 mol) of 2,4'-diaminodiphenyl ether, and 72 g of N-methylpyrrolidone while gaseous nitrogen was passed through the flask. With stirring, reaction was allowed to proceed at room temperature for 10 hours. Due to the formation of polyamic acids having a high molecular weight, the viscosity of the reaction system increased to such a degree that stirring became difficult. After addition of a small amount of water for controlling the molecular weight, the reaction mixture was heated at 60° C. After addition of 52 g of acetic anhydride and 26 g of pyridine, the resulting mixture was allowed to stand for 12 hours at room temperature. The obtained paste was introduced into methanol, and the precipitated fine particles of a solid resin were collected. After sufficiently washed by boiling it in methanol, the solid resin was dried under a reduced pressure at 80° C. for 10 hours, to obtain a powdery polyimide resin (reduced viscosity: 0.68 dl/g) having the repeating unit represented by the following formula.

1. customInto a four-neck flask equipped with a thermometer, a stirrer, and a nitrogen introducing tube
2. additioncharged
3. customreaction
4. temperaturethe viscosity of the reaction system increased to such a degree
5. stirringthat stirring
6. waitto stand for 12 hours at room temperature
7. customthe precipitated fine particles of a solid resin were collected
8. washAfter sufficiently washed
9. customthe solid resin was dried under a reduced pressure at 80° C. for 10 hours