| 摘要 |
<p>A process for producing a retardation film by the tenter method in which a thermoplastic resin film (20) is stretched in the width direction while heating it with hot air blown from the orifices of nozzles (30) and nozzles (32) which are disposed face to face on the upper side and the lower side, respectively, in an oven (100). The process for retardation film production comprises: a preheating step in which the thermoplastic resin film (20) is heated with hot air; a stretching step in which the preheated thermoplastic resin film (20) is stretched while heating it with hot air to obtain a stretched film (22); and a thermal fixing step in which the stretched film (22) is heated with hot air. In the preheating step, stretching step, and/or thermal fixing step, the hot air has an air velocity as measured at the orifices of 2-12 m/s, and the quantity of air blown per nozzle is 0.1-1 m/s per m of the nozzle in the film-width direction.</p> |
