| 摘要 |
PURPOSE:To obtain a material showing extremely sensitive reaction through the contact with water at 20 deg.C and developing large shrinking behavior without almost being dissolved, by using a PVA type strip-like molding prepared under a certain special condition. CONSTITUTION:An aqueous solution containing 35wt.%-60wt.% of carboxyl group modified polyvinyl alcohol is used as a molding raw liquid and emitted from a nozzle at 95 deg.C-160 deg.C and immediately formed into a strip-like molding using a special spinning cylinder consisting of a cooling zone of 0.1m-1.0m adjusted to 20 deg.C-50 deg.C and a pre-drying zone of 1m-8m adjusted to 80 deg.C-170 deg.C, more pref., to 90 deg.C-140 deg.C. Thereafter, the strip-like molding is dried to an almost absolute dry condition at 110 deg.C-145 deg.C. By this method, a heat stretching treatment condition necessary for imparting hard water-solubility and high speed shrinkability, that is, heat treatment such that stretching magnifying power is 4-7 times at stretching temp. of 190 deg.C-230 deg.C considered to be impossible heretofore can be performed.
|
