| abstract |
An object of the present invention is to provide a production method for obtaining a high-quality thin film optical film without causing breakage in a stretching process or the like of a solution casting method. In a solution casting film forming method, a dope, which is a raw material solution of an optical film, is cast on a support, a web (casting film) is formed on the support, and the web is peeled off from the support. In the method for producing an optical film, the casting draw ratio represented by the following formula (1) when casting the dope from the casting die to the support is 3 to 6, A method for producing a film. Formula (1) Casting draw ratio = Support speed / Discharge flow rate [Selection] |