Coatings and materials that are atomic oxygen resistant and have an atomically smooth surface that can reduce drag are disclosed. The coatings and materials can be used on at least a portion of a spacecraft intended to operate in harsh environments, such as stable Earth orbits at about 100 km to about 350 km.

A method of producing a joined body includes: providing a composition for transient liquid phase sintering to at least one of a portion of a first member to which a second member is to be joined and a portion of the second member to which the first member is to be joined, so as to form a composition layer; bringing the portion of the first member to which the second member is to be joined and the portion of the second member to which the first member is to be joined into contact with each other via the composition layer; and sintering the composition layer by heating, and the composition for transient liquid phase sintering includes metal particles capable of transient liquid phase sintering and a thermoplastic resin.

A composition includes metal particles capable of transient liquid phase sintering and a thermoplastic resin having a thermal decomposition rate of 2.0% by mass or less, the thermal decomposition rate being measured under a nitrogen stream using a thermogravimetric measurement device.

A liquid crystal photoalignment agent includes: a copolymer of diamine and dianhydride; and a compound Formula 1 below, wherein an amount of the compound of Formula 1 is less than about 10 weight %, based on a total weight of the liquid crystal photoalignment agent:

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R.sub.1 is a substituted or unsubstituted tetravalent organic group derived from an acid dianhydride, wherein the acid dianhydride is at least one of an aliphatic cyclic acid dianhydride or an aromatic acid dianhydride, R.sub.2 is a substituted or unsubstituted trivalent organic group derived from an aromatic diamine, at least one of R.sub.1 and R.sub.2 is substituted with CF.sub.3 or a silyl group, R.sub.3 is a residue of a compound including a substituted or unsubstituted aromatic group with a carbon number that is equal to or greater than 6, n is 1 to 5, and * represents a point of attachment.

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.

The present invention provides a novel polyimide resin adhesion enhancer having a fluorene framework, wherein a polyimide film produced using same exhibits conventional properties such as heat resistance and mechanical properties, and maintains adhesion with a carrier substrate while not being affected with respect to retardation even during a high-temperature process.

A thermoplastic polymer composition including 10 to 99 wt % of a phthalimidine copolycarbonate having a glass transition temperature of greater than 150 C., preferably greater than 170 C., as measured using differential scanning calorimetry; 1 to 90 wt % of a poly(etherimide-siloxane) copolymer; and 0 to 10 wt % of an additive is provided.

Problem: The invention provides a polyimide precursor as well as a resin composition thereof that is excellent in coating properties of slit coating as well as productivity and also excellent in optical properties that are required for applications of flexible substrates.

Solution: The polyimide precursor comprises a structure unit derived from a fluorene backbone and a silicon-containing structure unit, and a weight-average molecular weight of the polyimide precursor is 90,000 to 250,000.

A polyamic acid resin is copolymerized including: at least one diamine; at least one acid dianhydride; and polyhedral oligomeric silsesquioxane, and a transparent polyimide film is formed using the polyamic acid resin. The transparent polyimide film secures both excellent optical and mechanical properties through organic-inorganic hybrid formation, thus being applicable as a cover window for display devices.

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. The imide bonds are derived from an aromatic diamine monomer and a tetracarboxylic dianhydride monomer. The amide bonds are derived from an aromatic dicarboxylic acid dichloride monomer and an aromatic diamine monomer or is derived from the aromatic dicarboxylic acid dichloride monomer and an alkoxysilane containing an amine group or an isocyanate group.