Described are composite hollow fibers filter membranes that include a porous polymeric hollow fiber support and a filter layer; methods of making the composite hollow fibers and using the composite hollow fibers as a filter membrane; methods of making a filter component or filter from the composite hollow fiber, and filter components and filters that contain the composite hollow fibers as filter membranes.

After bringing a water-containing peeling liquid in contact with a thin flat film formed on a substrate, a support film including a cover film having one main surface thereof is laminated onto the flat film, such that the support film is in contact with the flat film, a cover film-attached laminate composed of a support film and a cover film is then separated from the substrate, and the laminate including the flat film and the support film is separated from the cover film-attached film.

To provide: a purification method which uses a polyimide and/or polyamide imide porous membrane that exhibits excellent removal performance for impurities such as metals, and wherein a liquid that is a silylating agent liquid, a film forming material or a diffusing agent composition is an object to be purified; a purification method for purifying a silicon compound-containing liquid that contains a silicon compound which is capable of producing a silanol group by hydrolysis; a method for producing a silylating agent liquid, a film forming material or a diffusing agent composition, which uses the purification method; a filter medium which is composed of the above-described porous membrane; and a filter device which comprises the above-described porous membrane. A purification method for purifying a liquid, which comprises a step in which some or all of the liquid is caused to permeate through a polyimide and/or polyamide imide porous membrane having communicating pores from one side to the other side by means of differential pressure, and wherein the liquid is a silylating agent liquid, a film forming material or a diffusing agent composition that is used for diffusing a dopant into a semiconductor substrate.

A carbon molecular sieve (CMS) membrane is made by pyrolyzing, to a peak pyrolysis temperature T.sub.P, a hollow fiber membrane having a polymeric sheath surrounding a polymeric core, anti-substructure collapse particles present in pores formed in the polymeric core help prevent collapse of pores formed in the hollow fiber membrane before pyrolysis. The anti-substructure collapse particles are made of a material or materials that either: i) have a glass transition temperature T.sub.G higher than T.sub.P, ii) have a melting point higher than T.sub.P, or ii) are completely thermally decomposed during said pyrolysis step at a temperature less than T.sub.P. The anti-substructure collapse particles are not soluble in a solvent used for dissolution of the polymeric material of the core.

An object of the present invention is to provide a gas separation membrane containing a novel sulfonated polyimide and having superior gas separation performance. The gas separation membrane of the present invention contains a sulfonated polyimide represented by the following general formula (1):

##STR00001##

wherein Ar is an aryl group, X is more than 0 and 1 or less, and M.sup.+ is H.sup.+ or a metal cation.

Provided are a porous film having excellent surface smoothness and a method for producing the same. The surface roughness of a porous film of polyvinylidene fluoride, polyethersulfone, polyimide and/or polyamide-imide is Ra 30,000 ? or less. The opening diameter of the porous film is preferably from 100 nm to 5000 nm. The method for producing a porous film preferably includes a step for kneading a varnish containing fine particles and at least one resin selected from the group consisting of polyvinylidene fluoride, polyether sulfone, polyamic acid, polyimide, polyamide-imide precursor, and polyamide-imide. The varnish preferably has a viscosity at 25? C. of 0.1-3 Pa.Math.s, a solids fraction concentration of 10-50 mass %, and a fine particle average particle size of 10-5000 nm.

A process for producing nitrogen-rich air by feeding high temperature air at 150? C. or more to an air separation membrane module is described. After being placed at 175? C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

A composite membrane comprising: a) a porous support; b) a gutter layer; and c) a discriminating layer which satisfies Formula (1): wherein: ? is <4; x is the arithmetic mean of N measurements of the thickness of the discriminating layer and has a value of between 30 and 150 nm; N is at least 100; x.sub.low.sub._.sub.meas is the thickness in nm of an individual measurement of thickness within the N measurements; x>x.sub.low.sub._.sub.meas>0; and n is the number of individual thickness measurements where x>x.sub.row.sub._.sub.meas, >0 $\begin{array}{cc}?=\frac{\stackrel{\_}{x}}{\left(N-n\right)}\left(n-\underset{i=1}{\overset{n}{.Math.}}\left(1-\frac{1}{x_{{\mathrm{low}}_{\mathrm{meas}}}}\right)\right)& \mathrm{Formula}\left(1\right)\end{array}$

A composite membrane comprising: (A) a porous support; (B) optionally a gutter layer; (C) a first discriminating layer; (D) an outermost layer; and (E) a non-discriminating layer interposed between the first discriminating layer (C) and the outermost layer (D); wherein the outermost layer (D) is a discriminating layer comprising a polyimide polymer.

A composite membrane comprising: a) a porous support; b) a gutter layer; and c) a discriminating layer;
wherein at least 10% of the discriminating layer is intermixed with the gutter layer.