| 摘要 |
<p>PURPOSE:To obtain the titled film having a low heat shrinkability and a high crystallinity with good productivity, by heat-treating a biaxially orientated poly- p-phenylenesulfide film at a specified temperature while it is stretched, and then heat-treating the thus treated film under specified conditions. CONSTITUTION:Poly-p-phenylenesulfide is formed into a film under pressure and heating, then after the film is immersed into water to be cooled quickly to obtain a transparent unorientated film, the film is orientated biaxially in longitudinal and lateral directions. Then the biaxially orientated film is heat-treated at a temperature in the range of Tm (Tm stands for the meltin point of the film measured by a differential scanning calorimeter)-350 deg.C while the film is stretched, and then is heat-treated at a temperature in the range of 150-350 deg.C to be shrunk by 20% or less in one direction or two directions, or shrunk or stretched by 25% or more in two directions or while the length is kept constant, so that the intended film is obtained.</p> |
