The present invention relates to a process for producing a polyester resin composition, including the step of mixing a polyester resin (A), an aromatic carbodiimide (B) and an aliphatic polycarbodiimide (C) at a temperature not lower than a melting temperature of the polyester resin, in which the polyester resin (A) and the aromatic carbodiimide (B) are mixed in the presence of the aliphatic polycarbodiimide (C).

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent, and a solvent is provided. The dissolvable polyimide is represented by formula 1:

##STR00001##

wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≦X≦0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A dry phase inversion process is performed on the polyimide membrane.

A polyvinylidene fluoride film composition and a polyvinylidene fluoride isolation film are provided. The polyvinylidene fluoride film composition includes a polyvinylidene fluoride, a polyetherimide, and a polyether-type nonionic surfactant. The weight ratio of the polyvinylidene fluoride to the polyetherimide is 1:1 to 19:1, and the content of the polyether-type nonionic surfactant is 0.1% to 10% by weight based on a total of 100% by weight of the polyvinylidene fluoride film composition.

A polyimide porous film includes: a polyimide porous film body; and at least one of resin particles and a resin porous film, the at least one of the resin particles and the resin porous film adhering to one surface or both surfaces of the polyimide porous film body, and containing a fluorine-based resin or containing a fluorine-based resin and an acrylic resin.

A fluorine-containing dispersion is disclosed, the solid content of the fluorine-containing dispersion including a fluorine-containing polymer powder and polyimide. The fluorine-containing polymer powder has a mass ratio greater than 85% in the solid content, and the polyimide has a mass ratio less than 15% in the solid content. An average particle size of the fluorine-containing polymer powder is less than or equal to 3 μm. A method of preparing the fluorine-containing dispersion, and a fluorine-containing composite film made using the fluorine-containing dispersion are also disclosed.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent, and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≤X≤0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A dry phase inversion process is performed on the polyimide membrane.

One piece, multifunctional window assemblies for use in vehicles, equipment, or structures and methods for making them is provided. The disclosed window assembly can include a protection panel and a structural panel each formed of a plurality of nanolaminated layers. The nanolaminated window assembly is self-supporting and does not need a frame. For particular applications, such as in an aircraft, the one piece, multifunctional, nanolaminated window can be directly attached to the fuselage to provide load bearing capability, a larger window area, impact protection, ice buildup prevention, and/or electromagnetic effect protection.

A resin film, in which at least one of polyimide layers is a non-thermoplastic polyimide layer having a linear thermal expansion coefficient of 1×10.sup.−6 to 30×10.sup.−6 (1/K), is shown. The non-thermoplastic polyimide layer is composed of a polyimide which is produced by reacting an anhydride component containing an aromatic tetracarboxylic anhydride with a diamine component, wherein the diamine component contains both a dimer acid-type diamine produced by replacing each of two terminal carboxyl groups in a dimer acid with a primary aminomethyl or amino group and an aromatic diamine, and the dimer acid-type diamine is contained in an amount of 1 to 15 mol % relative to the whole diamine component.

The present invention relates to a display film and, more particularly, to a display film comprising a substrate layer and a coating layer formed on one surface of the substrate layer, wherein a first critical radius of curvature measured in a direction in which the side surface of the coating layer becomes concave is at most about 10 mm, and a second critical radius of curvature measured in a direction in which the side surface of the substrate layer becomes concave is at most about 5 mm. The display film according to the present invention has a high surface hardness while exhibiting superior flexibility in both directions vertical to the plane direction of the film and thus is suitable for application as an outer window film for a display and particularly has the property of being applicable to a flexible display.

The present invention relates to a laminated film roll body, around which a laminated film is wound, the laminated film including: a first polyimide film; and a second polyimide film laminated on the first polyimide film and made of a fluorine-based, siloxane-based, or amine-based polyamic acid, wherein the second polyimide film has a glass transition temperature of 350° C. or higher when measured by a temperature elevation rate of 20° C./min. The laminated film roll body can be used in a continuous manufacturing process of a flexible device to improve process yield and efficiency.