| 摘要 |
<p>The present invention addresses the problem of providing a process for optical-film production which includes a coating step for simultaneous multiple coating and in which coating defects such as film thickness unevenness and streaks are less apt to occur. This process is a process for producing an optical film which comprises a base and, formed thereon, a multilayer film composed of a plurality of optically functional layers, and is characterized by including a coating step in which a lowermost-layer coating fluid that forms an optically functional layer in contact with the base and a coating fluid that forms another optically functional layer are simultaneously applied in a multilayer arrangement to the base at a given temperature and a given speed, wherein the lowermost-layer coating fluid has a viscosity in the range of 0.1-20 mPa·s at the given temperature and a concentrate obtained by concentrating the lowermost-layer coating fluid to 50 mass% has an average string length of 5 cm or shorter, when a glass rod having an outer diameter of 6 mm is vertically immersed in the concentrate to a depth of 3 cm and is then pulled vertically up at the given temperature and the given speed and the length of the string extending from the concentrate is measured at the time when the string breaks, the measurement being made five times.</p> |
