| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for casting a film from solution, capable of improving the absolute filtration accuracy of a cellulose acylate solution without decreasing the hole diameter of a filtering material and increasing the amount of the filtration treatment. <P>SOLUTION: This method for casting the film from the solution is provided by firstly introducing dope stock solution before filtration firstly into a body feed tank 28 and adding a filtering aid from a filtering aid tank 37 for dispersing. As the filtering aid, an aid having ≥50 % SiO<SB>2</SB>and a cellulose-based aid are mixed and used. The dope stock solution dispersed with the filtering aid is introduced to a filter 30 and filtered while forming a cake on the surface of the filtering material. After the filtration, a cleaning solution is supplied as circulating from a cleaning solution tank 38 and the cake is discharged as slurry. The filtering aid is separated from the slurry in a separating device 44, and the filtering aid is fired in a firing device 48. Regenerated filtering aid is sent to the filtering aid tank 37. After the cleaning treatment, a pre-coating liquid dispersed with the filtering aid is supplied to the filter 30 to form a pre-coat layer on the surface of the filtering material. <P>COPYRIGHT: (C)2004,JPO |
