| 摘要 |
PURPOSE:To obtain a biaxially oriented poly-p-phenylene sulfide film, which is thermally stable in dimensional change, mechanical characteristics, transparency and the like, by a method wherein poly-p-phenylene sulfide, which contains the required quantity or more of the specified repeating unit and has the specified melt viscosity, is molded into a sheet form and quenched and, after that, simultaneously biaxially oriented in the limited temperature range and finally thermoset at the specified temperature so as to set its density to the required value. CONSTITUTION:Poluy-p-phenylene sulfide, which contains 90% by mole or more of the repeating unit represented by the general formula and the melt viscosity of which at 300 deg.C and shearing speed of 200s<-1> is 100-600,000 poise, is melt-formed into a sheet form and quenched at a cooling speed of 5 deg.C/s or higher in order to obtain an amorphous film. In succession, the amorphous film is simultaneously biaxially oriented at 80-120 deg.C by the areal draw ratio of 400% or more. Further, the oriented film is thermoset at a temperature ranging from 180 deg.C to the melting point of the polymer in order to set the density of the film within the range of 1.330-1.400. The adopted thermosetting time varies from the unit of second to the unit of minute such as from about 1sec to the order of 10min. |
