A flame-retardant polyimide molding material containing a semi-aromatic polyimide resin (A) and further containing 15 to 80 mass % of either of the following component (B1) or component (B2): (B1) graphite (B2) a combination of two or more selected from the group consisting of graphite, a fluorine resin, and carbon fiber; and a molded article including the same.

In a first aspect, a polyimide film includes a dianhydride and a diamine. The dianhydride, the diamine or both the dianhydride and the diamine include an alicyclic monomer, an aliphatic monomer or both an alicyclic monomer and an aliphatic monomer. The polyimide film has a b* of 1.25 or less and a yellowness index of 2.25 or less for a film thickness of 50 μm. The polyimide film is formed by: (a) polymerizing the dianhydride and the diamine in the presence of a first solvent to obtain a polyamic acid solution; (b) imidizing the polyamic acid solution to form a substantially imidized solution; (c) casting the substantially imidized solution to form a film; and (d) drying the film.

A film for a metal layer laminate board and a metal layer laminate board have excellent stiffness, while capable of suppressing fluctuation of a dielectric constant before and after pressing. The film for a metal layer laminate board includes a porous resin layer having a tensile elastic modulus at 25° C. of 800 MPa or more and 2000 MPa or less.

A porous resin film for a metal layer laminate board and a metal layer laminate board are provided to suppress damage to a metal layer disposed on an inner peripheral surface of a through hole and to have excellent electrical connection reliability even under the high temperature environment. The porous resin film for a metal layer laminate board is used in lamination of a metal layer. The porous resin film for a metal layer laminate board has a minimum thermal expansion coefficient X in a plane direction perpendicular to a thickness direction and a thermal expansion coefficient Z in the thickness direction. In the porous resin film for a metal layer laminate board, a ratio (Z/X) of the thermal expansion coefficient Z in the thickness direction to the minimum thermal expansion coefficient X is 3.5 or less.

The present application provides a flexible substrate and a method of manufacturing the same. The flexible substrate includes a base substrate, the flexible substrate is a polyimide film, wherein the polyimide film comprises polyimide having a structural formula of ##STR00001##
and the polyimide has a rigid segment and a flexible segment. The polyimide film is divided into rigid regions and a flexible region, wherein the rigid region is mainly constituted by the rigid segment, and the flexible region is mainly constituted by the flexible segment. Because the polyimide has the rigid segment and the flexible segment, it is used in flexible substrates.

Provided according to the present invention is a substrate for a flexible display device in which the problems of threshold voltage shift-induced current fluctuation and resultant image sticking can be solved by introducing an imide monomer as an organic filler into a polyamic acid composition to enhance thickness and surface direction densities in the film that is manufactured while vulcanization is performed at high temperatures, thereby enhancing thermal diffusivity and thermal conductivity of the film.

A transparent polyimide mixture is disclosed. The transparent polyimide mixture includes a transparent polyimide, an additive, and a solvent. A molecular chain of the transparent polyimide includes an active hydrogen atom. The additive includes a carbodiimide group. An equivalent ratio of the active hydrogen atom and the carbodiimide group is in a range of 1:0.8 to 1:1.2. A method for preparing the transparent polyimide mixture, a transparent polyimide film, and a method for preparing a transparent polyimide film are also disclosed.

A device substrate is provided with an increased light transmittance that is a resin film resistant to thermal decomposition in high temperature processes, along with a production method for a device substrate, a device, and a production method for a device, where a resin composition designed to produce a resin film to be used as a substrate for a display device or light receiving device, comprises (a) a resin that has a repeating unit as represented by the chemical formula (1) or (2) as a primary component and (b) a chemical compound as represented by the chemical formula (3) and/or a condensation product thereof,

##STR00001##

wherein in the chemical formulae (1) and (2), X, Y, R.sup.1 and R.sup.2 are defined, and

Si(OR.sup.11).sub.n(R.sup.12).sub.4-n  (3)

wherein in the chemical formula (3), R.sup.11 and R.sup.12 are as defined.

A polymer of intrinsic microporosity having a repeating subunit including both a spirobisindane imide moiety and an amido (lactam) moiety.

##STR00001##

A monomer represented by Chemical Formula 1:

##STR00001##

wherein, in Chemical Formula 1, R.sup.1, R.sup.2, A.sup.1, A.sup.2, L.sup.1, L.sup.2, o, p, q, and r are the same as defined in the detailed description.