反应详情

温度

70 °C

5 parts of mercapto-terminated PVA (having an ethylene content of 0.5 mol %, a degree of polymerization of 550, a saponification degree of 88.3 mol % and a mercapto group content of 3.3×10−5 equivalent/g) (PVA-213) and 90 parts of ion-exchanged water were fed into a glass vessel equipped with a reflux condenser, a dropping funnel, a thermometer, a nitrogen inlet mouth and a stirrer, and completely dissolved at 95° C. Next, its pH was made to be 4 with diluted sulfuric acid added thereto, and then 10 parts of methyl methacrylate, 10 parts of n-butyl acrylate and 0.1 parts of n-dodecylmercaptan were added to it with stirring at 150 rpm. This was purged with nitrogen and heated up to 70° C. 5 parts of 1% potassium persulfate was added to it to start the polymerization. Then, a mixture of 40 parts of methyl methacrylate, 40 parts of n-butyl acrylate and 0.4 parts of n-dodecylmercaptan was continuously added to it, over a period of 2 hours. 3 hours after the start of the polymerization, the conversion reached 99.5%, and the polymerization was stopped in this stage. The process gave stable methyl methacrylate/n-butyl acrylate copolymer emulsion (Em-214) having a solid concentration of 52.0%.

1. custom5 parts of mercapto-terminated PVA (
2. customa degree of polymerization of 550
3. customequipped with a reflux condenser, a dropping funnel
4. dissolutiona thermometer, a nitrogen inlet mouth and a stirrer, and completely dissolved at 95° C
5. additionadded
6. customThis was purged with nitrogen
7. addition5 parts of 1% potassium persulfate was added to it
8. customthe polymerization
9. additionwas continuously added to it, over a period of 2 hours
10. custom3 hours after the start of the polymerization