A polyimide resin composition containing a polyimide resin (A) and a phosphinic acid metal salt-based flame retardant (B), the polyimide resin (A) containing repeating structural units of formulae (1) and (2):

##STR00001## wherein R.sub.1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R.sub.2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms; and X.sub.1 and X.sub.2 each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic ring, and a content ratio of the repeating structural unit of formula (1) with respect to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is 20 to 70 mol %.

A resin molded article having a microphase-separated structure, the resin molded article containing a polyimide resin (A) and a polyether ketone resin (B), the polyimide resin (A) containing repeating structural units of formulae (1) and (2):

##STR00001## wherein R.sub.1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R.sub.2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms; and X.sub.1 and X.sub.2 each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic ring, a content ratio of the repeating structural unit of formula (1) with respect to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is 20 to 70 mol %, and a weight average molecular weight Mw is 40,000 to 150,000.

A method of removing a photoresist, a laminate, a method of forming a metallic pattern, a polyimide resin, and a stripper are provided. The method of removing the photoresist includes forming a release layer on a substrate, the release layer having a first surface and a second surface opposite to each other, wherein the first surface of the release layer is in contact with the substrate; forming a photoresist layer on the second surface of the release layer; and removing the release layer and the photoresist layer. The release layer is formed by a polyimide resin. The polyimide resin is obtained by performing a polymerization of tetracarboxylic dianhydrides, diamines, and phenolamines. The diamines include hydroxyfluorinated diamines, benzoic acid diamines, and aminotetramethyldisiloxanes.

An object of the invention is to provide a cured film which is high in sensitivity, capable of forming a pattern in a low-taper shape after development, capable of the change in pattern opening width between before and after thermal curing, an excellent in light-blocking property, and a negative photosensitive resin composition that forms the film. The negative photosensitive resin composition contains an (A) alkali-soluble resin, a (C1) photo initiator, and a (Da) black colorant, where the (A) alkali-soluble resin contains a (A1) first resin including one or more selected from the group consisting of a (A1-1) polyimide, a (A1-2) polyimide precursor, a (A1-3) polybenzoxazole, and a (A1-4) polybenzoxazole precursor, and has a structural unit having a fluorine atom at a specific ratio, and the (C1) photo initiator contains an (C1-1) oxime ester-based photo initiator that has a specific structure.

A flexible electronic device containing a polyimide film exhibiting excellent C-V characteristics. The polyimide film is a film that shows a maximum gradient of 0.005N or more in a capacitance-voltage measurement of a laminate in which a polyimide film having a film thickness of 0.75 μm is formed on a silicon wafer having a resistance value of 4 Ωcm; the maximum gradient meaning a maximum value of an absolute value of a gradient in a normalized capacity-voltage curve during a third scan of forward direction scans; a capacity-voltage curve being measured by applying a direct current voltage is to the polyimide film with respect to the silicon wafer between a lowest voltage V1 and a highest voltage V2, and measuring capacitance while the direct current voltage is scanned in a forward direction and scanned in a negative direction; the normalized capacity-voltage curve is being normalized so that the capacity at the lowest voltage V1 is 1.

A benzocyclobutene-containing polyimide resin and a benzocyclobutene-containing polyimide resin composition are provided. The composition includes: (a) a filler:hollow silica, a perfluoroalkoxy alkane resin, or a combination thereof, and (b) a benzocyclobutene-containing polyimide resin with characteristics of high heat resistance, low dielectric property, low elastic modulus, and suitable for manufacturing a redistribution layer and a polyamide film of a semiconductor packaging material in a high-speed and high-frequency field.

The present invention provides a photosensitive polyimide composition comprising a polyimide resin having a structural unit represented by the formula (1) and a structural unit represented by the formula (2), a quinonediazide sulfonate, a thermal curing agent, and a thermal acid generator. ##STR00001## In the formulas (1) and (2), n is an integer of 10 to 600, Ar.sub.1 is a tetravalent organic group; Ar.sub.2 is a divalent to tetravalent organic group; Ar.sub.3 is a divalent aromatic group; and R.sub.1 is an OH group or a COOH group. The present invention also provides a photoresist film made of the above-mentioned photosensitive polyimide composition.

The present disclosure relates to nanoporous micro-spherical polyimide aerogels and a method for preparing the same. The use of the method for preparing polyimide aerogels, according to an embodiment of the present disclosure, enables the preparation of the polyimide aerogels through a low-temperature process, and thus can save energy and time when compared with existing preparing methods, can reduce production costs, and can prepare spherical polyimide aerogels, which are micro-sized uniform particles, having excellent chemical stability, thermal insulation characteristics, and absorption-desorption characteristics while having nano-sized pores. The spherical polyimide aerogels can be applied to various fields, such as an insulator, a drug delivery medium, and a catalyst supporter, due to excellent physical properties thereof.

A polyimide resin composition obtained by blending a polyimide resin (A) and glass fiber (B), the polyimide resin (A) containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), a content ratio of the repeating structural unit of the formula (1) with respect to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) being 20 to 70 mol %, wherein R.sub.1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R.sub.2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms; and X.sub.1 and X.sub.2 each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic ring.

##STR00001##

A poly(imide-ester-amide) copolymer and an optical film are provided. The poly(imide-ester-amide) copolymer includes imide bonds, ester bonds, and amide bonds. A molar ratio of the imide bonds, the ester bonds, and the amide bonds is 40 to 80:10 to 30:5 to 30.