Ube Industries, Inc.

Ube Corporation

Shusei Ohya

Makoto Matsuo

Keita Bamba

Yuuichi Fujii

Provided are: a porous polyether sulfone film having macrovoids and having excellent dimensional stability; and a production method therefor. Provided is a porous polyether sulfone film having a surface layer (a), a surface layer (b), and a macrovoid layer interposed between the surface layer (a) and the surface layer (b). The macrovoid layer has a partition wall joined to the surface layers (a) and (b) and a plurality of macrovoids surrounded by the partition wall and the surface layers (a) and (b). The surface layer (a) and the surface layer (b) have pores connected to the macrovoids.

Porous polyether sulfone film and production method therefor

The present invention pertains to a porous polyimide film production method and a porous polyimide film produced using said method, said method including: a step (1) in which a poly(amic acid) solution comprising 40%-97% by mass organic polar solvent and 3%-60% by mass poly(amic acid) having an intrinsic viscosity, comprising tetracarboxylic acid units and diamine units, of 1.0-3.0 is cast in film form and immersed in or caused to come in contact with a coagulating solvent having water as an essential component thereof, and a porous film of poly(amic acid) is produced; and a step (2) in which the porous film of poly(amic acid) obtained in said step is heat treated and imidized. Shrinkage in the film longitudinal direction and transverse direction after heat treatment is suppressed to no more than 8% for each direction and the speed of temperature increase in a temperature range of at least 200&#xb0; C. during the heat treatment is at least 25&#xb0; C./min.

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Yamaguchi, Japan

Shusei Ohya