公开(公告)号：US6054530A

公开(公告)日：2000-04-25

申请号：US38544

申请日：1998-03-11

申请人： Stephen Charles Webb ,  James Francis Nangeroni ,  Brian Thomas Carvill ,  Beth Ann Frey

发明人： Stephen Charles Webb ,  James Francis Nangeroni ,  Brian Thomas Carvill ,  Beth Ann Frey

IPC分类号： C08F6/06 ,  C08F8/12 ,  C08F16/06 ,  C08F8/00

CPC分类号： C08F8/12 ,  B29C47/00

摘要： An improved process for the continuous production of poly(vinyl alcohol) which involves purifying poly(vinyl acetate) paste exiting from a polymerization reactor and dissolving the substantially pure poly(vinyl acetate) in a hydrolytic alcohol-containing solvent for subsequent saponification to produce poly(vinyl alcohol). Poly(vinyl acetate) paste, containing poly(vinyl acetate), vinyl acetate, and solvent, is heated to a temperature above the glass transition temperature but below a temperature which will degrade the poly(vinyl acetate) and is fed into a flashing area of an extruding devolatilization device. Vinyl acetate and solvent are flashed through vent ports in the flashing area of the devolatilization device and can then be recycled to a polymerization reactor, if desired. A substantially pure poly(vinyl acetate) melt, exiting the flashing area, is conveyed to a mixing area of the devolatilization device where it is mixed with a hydrolytic alcohol-containing solvent to form a solution for subsequent processing in a saponification unit.

摘要翻译： 一种用于连续生产聚（乙烯醇）的改进方法，其涉及纯化从聚合反应器中排出的聚（乙酸乙烯酯）糊料，并将基本上纯的聚（乙酸乙烯酯）溶解在含有水解醇的溶剂中用于随后的皂化以产生聚 （乙烯醇）。 将含有聚（乙酸乙烯酯），乙酸乙烯酯和溶剂的聚（乙酸乙烯酯）糊料加热到高于玻璃化转变温度但低于将使聚（乙酸乙烯酯）降解的温度并且被送入闪蒸区域 的挤出脱挥装置。 乙酸乙烯酯和溶剂通过脱挥发分装置的闪蒸区域中的排气孔闪光，然后如果需要可以再循环到聚合反应器中。 将离开闪光区域的基本上纯的聚（乙酸乙烯酯）熔体输送到脱挥发分装置的混合区域，在该混合区域与含水解醇的溶剂混合以形成用于随后在皂化单元中处理的溶液。