PLATE-LIKE FILTER MEDIUM
Document Type and Number:
Japanese Patent JP3948056
PROBLEM TO BE SOLVED: To curb a pressure increase over time during a high precision filtration process and enhance filtration properties and prolong the life of a filter medium by coating the surface of a metal fiber substantially with a heat-resistant resin, in the plate-like filter medium, composed mainly of the metal fiber, the amount of air permeation of which shows a specific value at the time of a specific differential pressure.
SOLUTION: In the plate-like filter medium, composed mainly of a metal fiber, which is used for the purpose of removing foreign matter contained in polymer at the time of polymerization of polyester, nylon or acrylic monomer and shows the amount of air permeation of 0.5-10 L/cm2/min when the differential pressure is 30 mmH2O, the surface of the metal fiber is coated with a substantially heat-resistant resin. Thus the surface of the metal fiber is shut off the contact with the polymer, so that the production of foreign matter on the surface of the metal fiber due to the chemical reaction between the metal and the polymer is inhibited. The heat-resistant resin to be used is preferably, silicone resin or polyimide resin. In addition, the average diameter of the fiber constituting a metal fiber unwoven fabric layer with a smallest fiber diameter is preferably 5-30 μm.
April 27, 2007
July 11, 1997
TORAY IND INC
B01D39/20; B01D29/11; B01D29/39; B01D29/46; B29B13/10; C08J3/11; B01D39/20; B01D29/11; B01D29/39; B01D29/44; B29B13/10; C08J3/02; (IPC1-7): B01D39/20