| 摘要 |
PCT No. PCT/FR96/00686 Sec. 371 Date Nov. 4, 1997 Sec. 102(e) Date Nov. 4, 1997 PCT Filed May 6, 1996 PCT Pub. No. WO94/34897 PCT Pub. Date Nov. 7, 1996A poly(vinyl alcohol) purification process is described, which includes heat treating a poly(vinyl alcohol) under agitation in an atmosphere unsaturated by water and with a water vapor mass content of 20 to 100%. The process of the invention may also include an additional drying step. A poly(vinyl alcohol) with an alcohol content, more particularly a methanol content, of lower than 1% and an ester content, more particularly a methyl acetate content, of lower than 1% is also described, which is provided in the form of flakes a few millimeters in size or of a powder with an average particle size advantageously higher than 600 mu m. |
