| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a stretched film having slow axis accuracy higher than that of a conventional one and excellent flatness. <P>SOLUTION: The method of manufacturing the stretched film includes a preheating step by preheating roll, a heating step by a float system heating device and a heat removal step by a heat removal roll, and a thermoplastic resin film passes through these steps in this order and longitudinally uniaxially stretched using the difference of the peripheral speed between the preheating roll an the heat removal roll. The float system heating device is divided into at least three divisions extended in a film flow direction, the temperature of respective divisions satisfies a specific relation and further the temperature of the k-th division and the temperature of k+1-th division from the upstream of the float system heating device satisfy a specific relation, a step giving 10-500 N/m tension in the film width direction is provided between the heating step and the heat removal step and in such a case, the temperature of the film and the temperature of the division at the most downstream of the float system heating device satisfy a specific relation. <P>COPYRIGHT: (C)2009,JPO&INPIT |
