Porous polyimide shaped article
AssigneeFuji Xerox Co., Ltd.
InventorsHajime Sugahara, Hidekazu Hirose, Katsumi Nukada, Tomoya Sasaki, Kosaku Yoshimura, Akira Imai
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Abstract
A porous polyimide shaped article has a thickness in a range from 550 μm to 3,000 μm and has a relative dielectric constant of 1.8 or less and a dielectric loss tangent of 0.01 or less at 1 MHz. The porous polyimide shaped article satisfies the following formula: 1.2≤A≤1.6 wherein A represents a square root of a ratio of a pore size D84 where a cumulative percentage by number of pores from smaller sizes is 84% to a pore size D16 where the cumulative percentage by number of the pores from smaller sizes is 16% ((D84/D16)1/2) in a pore size distribution measured by mercury intrusion porosimetry.
Claims9
A porous polyimide shaped article comprising:
- the porous polyimide shaped article having a thickness in a range from 550 μm to 3,000 μm and having a relative dielectric constant of 1.8 or less and a dielectric loss tangent of 0.01 or less at 1 MHz, the porous polyimide shaped article satisfying the following formula:
- 1.2≤A≤1.6
- wherein A represents a square root of a ratio of a pore size D84 to a pore size D16 ((D84/D16)1/2), and D16 and D84 respectively represent pore diameters at 16% and 84% points on an accumulation curve of a pore size distribution measured by mercury intrusion porosimetry when a total number of pores in the porous polyimide shaped article is 100%,
- wherein the porous polyimide shaped article contains spherical voids, wherein a percentage of voids having a ratio of a major axis to a minor axis (major axis/minor axis) of more than 1.5 is 20% or less.
Dependencies are inferred from the claim text.