A polyimide film according to the present invention can be effectively used as a substrate for a flexible display device without a deterioration in heat resistance even at a temperature of 350° C. or higher since a coefficient of thermal expansion (A) in the section of 100-350° C., of the polyimide film, and a coefficient of thermal expansion (B) in the section of 350-450° C., of the polyimide film, meet 0<B/A<2.

Provided is such a cyclic imide resin composition where although it has a fast curability and a cured product thereof has a low relative permittivity, a low dielectric tangent and an excellent heat resistance, the composition itself has a high adhesive force. The cyclic imide resin composition contains: (a) a cyclic imide compound represented by the following formula (1) and having a weight-average molecular weight of 2,000 to 1,000,000,

##STR00001## wherein A independently represents a tetravalent organic group having a cyclic structure, B independently represents a divalent hydrocarbon group that may contain a hetero atom and has not less than six carbon atoms, X independently represents a hydrogen atom or a methyl group, m is 1 to 1,000; (b) an epoxy compound; and (c) a polymerization initiator containing at least two types of polymerization initiators which are a radical polymerization initiator (c-1) and an anionic polymerization initiator (c-2).

A resin film according to one aspect of the present invention contains polyimide, and satisfies the condition “the electric charge change in film after irradiation with a light having a wavelength of 470 nm and an intensity of 4.0 μW/cm.sup.2 for 30 minutes relative to before irradiation with the light is 1.0×10.sup.16 cm.sup.−3 or less.” Such a resin film can be used as a substrate for a semiconductor element to form an electronic device including the resin film, and a semiconductor element formed on the resin film.

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.

Novel aromatic polyimides, both thermoplastic and thermosettable, are disclosed based on use of asymmetric diamines and symmetric dianhydrides with either a functional endcap for further thermosetting or a non-functional endcap for retention of thermoplastic properties. Both aromatic polyimides have sufficient physical properties to be useful in 3D printing.

A thermoset barrier film including: a reaction product of the formulas (I), (II), (III), (IV), or a mixture thereof, as defined herein. Also disclosed are methods of making and using the thermoset barrier film, and devices incorporating the thermoset barrier film.

The invention broadly relates to release layer compositions that enable thin wafer handling during microelectronics manufacturing. Preferred release layers are formed from compositions comprising a polyamic acid or polyimide dissolved or dispersed in a solvent system, followed by curing and/or solvent removal at about 250° C. to about 350° C. for less than about 10 minutes, yielding a thin film. This process forms the release compositions into polyimide release layers that can be used in temporary bonding processes, and laser debonded after the desired processing has been carried out.

A poly(etherimide) includes repeating units derived from polymerization of a biphenol dianhydride and an organic diamine. A method of making the poly(etherimide) includes contacting the biphenol dianhydride and the organic diamine under conditions effective to provide a poly(etherimide). The poly(etherimide) can be useful in a variety of articles, for example in an optoelectronic component.

A polymer is disclosed, represented by Chemical Formula 1 or Chemical Formula 2: ##STR00001## wherein, in Chemical Formula 1 and Chemical Formula 2, Ar.sup.1, Ar.sup.2, R.sup.3, s, x, and y are defined in the detailed description.

A liquid crystal display including a first substrate, a thin film transistor disposed on the first substrate, a first electrode connected to the thin film transistor, and a first alignment layer disposed on the first electrode, wherein the first alignment layer includes polyimide and a capping group connected to a main chain end of the polyimide, and the capping group contains at least one of a first compound represented by the following Chemical Formula 1, and a second compound represented by the following Chemical Formula 2: ##STR00001## A1 and A2 are, independently of each other, an aromatic compound having 4 to 20 carbon atoms or an aliphatic cyclic compound having 4 to 20 carbon atoms; and B1 and B2 are, independently of each other, a crosslinking reaction group containing an alkylene group (—C.sub.nH.sub.2n—, n is a natural number).