WE CLAIM:
1. A filter medium comprising a fiber layer and a
catalyst layer,
the catalyst layer containing a catalyst and fibril fibers as main components.
2. The filter medium according to claim 1, comprising
two or more fiber layers,
the catalyst layer being disposed on at least one interlayer of the two or more fiber layers.
3. The filter medium according to claim 1, wherein the catalyst layer is disposed on the outermost layer of at least one surface.
4. The filter medium according to any one of claims 1 to
3, wherein a total content of the catalyst in the catalyst
layer per unit area of the catalyst layer is 150 to 600
g/m2.
5. The filter medium according to any one of claims 1 to
4, wherein the fiber layer contains 70% by mass or more of
polytetrafluoroethylene fibers, and the CV value of the
fiber diameter of the polytetrafluoroethylene fibers is 10%
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or less.
6. A bag filter comprising the filter medium according
to any one of claims 1 to 5, wherein
the filter medium is cylindrical.
7. A method for producing a filter medium comprising the
steps of:
wet papermaking a slurry containing a catalyst and fibril fibers to obtain a catalyst layer; and
laminating the catalyst layer and a fiber layer.
8. The method for producing a filter medium according to
claim 7, wherein the step of laminating the catalyst layer
and the fiber layer is a step of laminating the catalyst
layer and the fiber layer by needle punching.
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