| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a casted film superior in flatness by peeling off the casted film from a casting drum without leaving any part of the film. <P>SOLUTION: A hydrophobic layer 32c is formed at a position (an area for forming a lug) A1 which is a circumferential face 32b of the casting drum 32 and both ends of the casted film are positioned. The hydrophobic layer 32c is made of a PTFE and its contact angle with water is made at least 90 degrees. The part put between two of the area for forming a lug A1 is used as a product forming area A2. A smooth layer 32d without a surface defect but superior in flatness is made on the product forming area A2. A dope is casted on the surface of the casting drum 32 by using a casting die. The casting drum 32 is rotated, then a casted film 33 is formed on the surface of the casting drum 32. The casted film 33 obtains a self-sustaining property by being cooled and gelated on the casting drum 32 and is peeled off. Owing to a water repellency by hydrophobic layer 32c, a smooth peeling can be conducted without residue at the lug part of the casted film 33. <P>COPYRIGHT: (C)2009,JPO&INPIT |
