An LED light bulb is provided. The LED light bulb includes a lamp housing, a bulb base, a stem, first and second conductive supports, a driving circuit, and a flexible LED filament. The flexible filament includes two conductive electrodes, a first LED section, a second LED section, and a conductive section. The first LED section is bent in a first space curved shape. The second LED section is bent in a second space curved shape. The conductive section includes a center point of the flexible LED filament. The flexible LED filament is bent in a third space curved shape comprising the first space curved shape and the second space curved shape.

A polyimide composition for a package structure is provided. The polyimide composition includes a polyimide precursor, a cross-linker, a photosensitizer, a first additive, a second additive and a solvent. The first additive comprises a polyether based compound, and the second additive comprises a siloxane based compound. The polyimide composition has more than 98% cyclization of the polyimide precursor when the polyimide composition is cured at a temperature range of 160 C. to 200 C.

A method for producing an aromatic bisimide includes reacting a dialkali metal salt of a dihydroxy aromatic compound with a reactive substituted phthalimide under conditions effective to form a product mixture, introducing the product mixture to a liquid-liquid extraction column including an aqueous alkali metal hydroxide solution, and recovering from the liquid-liquid extraction column a purified aromatic bisimide having less than 500 ppm of residual dialkali metal salt of the dihydroxy aromatic compound, the corresponding dihydroxy aromatic compound, the corresponding mono-substituted salt of the dihydroxy aromatic compound, or a combination including at least one of the foregoing. A method for the manufacture of a polyetherimide from an aromatic bisimide prepared by the above method is also disclosed. A polyetherimide having less than 100 ppb of residual bisphenol A and an article made therefrom are also described.

A polyimide that is a reaction product of a diamine represented by Chemical Formula 1, a diamine represented by Chemical Formula 2, and a tetracarboxylic dianhydride represented by Chemical Formula 3:

##STR00001## wherein, in Chemical Formulae 1 to 3, L.sup.1, L.sup.2, R.sup.a to R.sup.f, m, R.sup.2, R.sup.10, R.sup.12, R.sup.13, n7, and n8 are the same as defined in the specification.

A polyimide (PI) having two COOH capping groups at each end is provided. A coating composition is further provided, which contains the PI and a hardening agent having 2 to 6 functional groups capable of reacting with COOH. A PI coating layer and PI film formed by the coating composition of the present invention possess excellent chemical resistance and coefficient of thermal expansion (CTE), which makes them applicable in fabrication of protective materials for active/passive devices, optical materials, touch panels, copper foil substrates, soft flexible electronic materials or integrated circuit elements, or film substrate for glass film touch panels.

The present invention provides a resin composition which can result in a cured film which has chemical resistance, low stress property, and high elongation property even by a heat treatment at a low temperature.

The resin composition comprising an alkali-soluble resin (a) which contains a phenol skeleton having a crosslinking group and a phenol skeleton not having a crosslinking group and which has a weight average molecular weight in the range of 1,000 to 50,000, wherein the content ratio of the phenol skeleton having a crosslinking group to the total 100% by mole of structural units of the phenol skeleton having a crosslinking group and the phenol skeleton not having a crosslinking group is in the range of 5 to 90% by mole.

A resin and a photosensitive resin composition whereby a cured film exhibiting high extensibility, reduced stress, and high adhesion to metals can be obtained are provided. A resin (A) including a polyamide structure and at least any structure of an imide precursor structure and an imide structure, wherein at least any of the structures of the resin (A) include a diamine residue having an aliphatic group.

A resin composition for a display substrate, the resin composition including a solvent and a heat-resistant resin or a precursor thereof, wherein the solvent has as a main component an amide compound having a surface tension of 35 mN/m or less at 25? C. Provided is a resin composition for a display substrate, whereby pinholing of a thin film is not prone to occur.

Polyimide-network battery-separator compositions are disclosed. The polyimide-network battery-separator compositions comprise a porous cross-linked polyimide network comprising a polyamic acid oligomer. The polyamic acid oligomer (i) comprises a repeating unit of a dianhydride and a diamine and terminal functional groups, (ii) has an average degree of polymerization of 10 to 70, (iii) has been cross-linked via a cross-linking agent, comprising three or more cross-linking groups, at a balanced stoichiometry of the cross-linking groups to the terminal functional groups, and (iv) has been chemically imidized to yield the porous cross-linked polyimide network. The polyimide-network battery-separator compositions also comprise an electrolyte composition comprising (i) a room temperature ionic liquid and (ii) a lithium ion. The electrolyte composition is interfused within the porous cross-linked polyimide network. Polyim ide-urea-network battery-separator compositions also are disclosed. Voltaic cells comprising a cathode, an anode, and the polyimide-network battery separator composition or the polyimide-urea-network battery separator composition are also disclosed.

The present invention provides a polyimide film which, by having a fluorine structure adopted into a rigid polyamide chain structure, exhibits not only superb heat resistance but also enhanced optical properties. Additionally, the polyimide according to the present invention, by having the particular structure, exhibits excellent transparency, heat-resistance, mechanical strength and flexibility, and thus can be utilized in a variety of functions such as an element substrate, display cover substrate, optical film, integrated circuit (IC) package, adhesive film, multi-layered flexible printed circuit (FPC), tape, touch panel, and protective film for optical disks.