| 摘要 |
PURPOSE:To obtain a homogeneous biaxially stretched polyphenylene sulfide film having excellent flatness, mechanical characteristics by specifying p- phenylene sulfide unit content and unmelted nucleus residue. CONSTITUTION:Polyphenylene sulfide is used mainly as an object of a poly-p- phenylene sulfide in such a manner that p-phenylene sulfide unit of 90mol% or more exist. This polyphenylene sulfide film needs 10 pieces/g or more of unmelted nucleus residue. The residue is obtained by observing substantially unstretched amorphous sheet under a transmission polarization microscope and counting nuclei of a size having one side of 50mum or more. The residue is controlled by a cylinder temperature, retention time and shearing speed of an extruder when it is pelletized and/or extrusion molded to an amorphous film. Thus, a biaxial stretched polyphenylene sulfide film having excellent flatness, mechanical characteristics is obtained. |
