Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)?Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300? C. with air flow of less than 500 Gurley seconds.

The present invention discloses multistage membrane apparatus and a method for separating gases from a crude gas stream a gas to be separated, a main remaining gas and optionally one or more further gas components, wherein in the apparatus comprises a feed stream separation stage, a first permeate separation stage and a second permeate separation stage, each stage being a membrane separation stage with gas separation membranes.

There is provided a production method for a resist composition purified product, which includes a step (i) of filtering a resist composition with a filter having a porous structure in which adjacent spherical cells are connected to each other. The filter includes a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamide imide. The resist composition contains a base material component (A) that exhibits changed solubility in a developing solution under action of acid, an onium salt, and an organic solvent component (S), where the content of the organic solvent component (S) is 97% by mass or more.

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.

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.

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.

A composite membrane comprising: a) a porous support; b) a gutter layer, a portion of which is present within the support and a portion of which is outside of the support; and c) a discriminating layer on the gutter layer; wherein: (i) the portion of the gutter layer outside of the support has an average thickness (GL.sub.e) of 10 nm to 900 nm; and (ii) the portion of the gutter layer present within the support has an average thickness (GL.sub.i) of 10% to 350% of GL.sub.e.

A composite membrane comprising: (a) a porous support; (b) a gutter layer; (c) a discriminating layer having an average thickness of at most 90 nm; and (d) a protective layer having an average thickness 150 nm to 600 nm comprising dialkylsiloxane groups.

A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of increasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises more than 35 mol % and up to 90 mol % of polar gas(es).

A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of decreasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises 1 to 35 mol % of polar gas(es).