In a first aspect, a polyimide film includes a polyimide derived from a dianhydride and a diamine. The dianhydride includes pyromellitic dianhydride, the diamine includes a benzimidazole, the molar ratio of dianhydride to diamine that forms the polyimide is in a range of from 0.85:1 to 0.99:1, and the polyimide film has a T.sub.g of 400° C. or higher, a tensile modulus of 6.0 GPa or more, and a coefficient of thermal expansion of 15 ppm/° C. or less over a temperature range of 50 to 500° C. In a second aspect, an electronic device includes the polyimide film of the first aspect.

An air-permeable filter material that includes a polymeric aerogel having a polymeric matrix comprising an open-cell structure is disclosed. The air-permeable filter material can be included in a mask, which can be configured to be placed over a user's mouth and/or nose. The mask can include at least one layer of the air-permeable filter material and is positioned such that inhaled and/or exhaled air of the user passes through the filter material.

A positive photosensitive resin composition and, more specifically, a positive photosensitive resin composition includes an alkali-soluble polymer resin comprising a polyimide precursor comprising a specific chemical structure; a quinone diazide compound; and a solvent. The positive photosensitive resin composition is a suitable matter for next-generation flexible displays and semiconductor packages.

A porous film includes at least one porous polyimide film that includes a polyimide resin, an organic amine compound and a resin other than a polyimide resin, and that does not include a polar aprotic solvent, wherein a content of the organic amine compound is 0.001% by weight or higher with respect to a total weight of the porous polyimide film.

Provides an alkali-resistant black matte polyimide film, including polyimide in an amount from 75 to 93 wt % of the alkali-resistant black matte polyimide film, in which dianhydride and diamine are polymerized to form a polyimide precursor, and the polyimide precursor is chemically cyclized to form the polyimide, wherein the dianhydride includes pyromellitic dianhydride (PMDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), and the diamine includes p-Phenylenediamine (PDA) and 4,4′-oxydianiline (ODA), and wherein the BPDA is an amount from 2 to 35 wt % of the dianhydride, and the PDA is in an amount from 10 to 70 wt % of the diamine; carbon black in an amount from 2 to 8 wt % of the alkali-resistant black matte polyimide film; and polyimide micropowder having a particle size between 2 and 10 μm and being in an amount from 5 to 10 wt % of the alkali-resistant black matte polyimide film.

An object is to provide a polyamic acid resin composition that can form a varnish with a low viscosity and serves to produce, through curing, coat film with good mechanical characteristics. Another object is to provide a polyamic acid resin composition in which the acid anhydride terminal group is low in reactivity with diamine and which can give a varnish that does not suffer significant precipitation of diamine. These objects can be met by a polyamic acid resin composition that contains: (a) polyamic acid and (b) a compound as represented by chemical formula (1). (In Chemical formula (1), Z is a di- or higher-valent organic group containing 2 or more carbon atoms, V is a structure as represented by chemical formula (2), and k is an integer of 2 or more.) (In In Chemical formula (2), δ represents oxygen or sulfur atom and W represents an electron-withdrawing group, and R.sup.11 and R.sup.12 represent independently a hydrogen atom or a hydrocarbon group containing 1 to 10 carbon atoms.

A polyimide-based composition includes a polyimide precursor and a solvent, in which the polyimide precursor includes repeating units represented by Chemical Formula 1 to 3. A polyimide film is also made from the composition.

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A multilayered polyimide film includes a first polyimide layer containing fluorine-containing polymer particles and having a first surface and a second surface, and a second polyimide layer and a third polyimide layer respectively disposed on the first surface and the second surface. The second and the third polyimide layers contain organic silicon oxygen compound particles. The multilayered polyimide film has a coefficient of thermal expansion (CTE) between about 13 and about 30 ppm/° C.

A high temperature resistant polyimide film and its preparation method. The present invention relates to a polyimide film and its preparation method and solves the problems of honeycomb's and skin panel's core adhesive-polyimide film with insufficient heat resistance, no climbing of bonding core structure and adhesive fillet formation. The high temperature resistant polyimide film is made by polyimide solution, inorganic filler modifier and interface coupling agent by the steps of: under specific temperature and stirring conditions, adding inorganic filler modifier and interface coupling agent to polyimide solution, stirring to obtain the adhesive agent; filtering and degassing the adhesive agent, casting to a stainless steel drum with carrier cloth and release paper to obtain a self-supporting film; then heating and annealing to obtain the final polyimide film. The present invention is applied to high temperature resistant polyimide film and its preparation method.

A polyetherimide composition is disclosed including a polyetherimide sulfone having a glass transition temperature of 240 to 320 C, preferably 245 to 312 C, and a particulate, thermally conductive filler composition. A layer of the polyetherimide composition resists deformation as determined by IPC method TM-650 when subjected to a lead-free solder reflow process at a temperature of greater than or equal to 260 C, preferably 260 to 350 C. A layer including the polyetherimide composition further has a thermal conductivity of 2.5 to 15 W/mK, preferably 3 to 12 W/mK, as determined in accordance with ISO 22007-2:2008.