摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing dope, capable of preventing foreign matter, such as a gel-like material and a film formed therefrom, from being mixed into concentrated dope, and further capable of making a polymer concentration of the dope uniform, before and after the dope is concentrated. SOLUTION: In this method, a mixed liquid 14 is prepared by feeding TAC, a solvent, and an additive into a mixing tank 11. The mixed liquid 14 is transferred to a heating machine 20 by a pump 15 and heated at 90°C. The mixed liquid 14 is passed through static mixers 21 and formed into low concentration dope. The low concentration dope is excellent in homogeneity, because of being passed through the static mixers 21. The low concentration dope is jetted into a flash tank 30. The low concentration dope is concentrated and formed into a high concentration dope 17. The high concentration dope 17 in the container is taken out by a pump 50. The high concentration dope 17 is passed through static mixers 52, after a temperature of the dope is controlled by a heating machine 51, so that the homogenous dope is prepared. COPYRIGHT: (C)2006,JPO&NCIPI |