A protective film has a soluble polyimide polymer base layer and an exterior layer directly containing the base layer exterior surface. The base layer is less than 12 microns thick, and is at least 2 meters long. The exterior layer includes at least one of a fluorinated polymer, a dielectric layer, one or more metallic layers, a metalloid layer, or a plurality of dielectric layers where each dielectric layer has a dielectric layer thickness that varies no more than 3%. The exterior layer or the as layer can also include additives, as desired.

The present invention aims to provide a curable resin composition capable of providing a cured product that has a high glass transition temperature after curing and is excellent in thermal decomposition resistance, adhesiveness, and long-term heat resistance. The present invention also aims to provide a cured product of the curable resin composition, an adhesive containing the curable resin composition, and an adhesive film, a coverlay film, a flexible copper clad laminate, and a circuit board each formed using the curable resin composition. Provided is a curable resin composition containing: a curable resin; an imide oligomer having an imide skeleton in a main chain and a crosslinkable functional group at an end and having a number average molecular weight of 4,000 or less; and a curing accelerator, a cured product of the curable resin composition having an initial adhesive force to polyimide of 3.4 N/cm or more, the cured product after storage at 200° C. for 100 hours having an adhesive force to polyimide of at least 0.8 times the initial adhesive force.

The present invention relates to a window cover film and a flexible display panel including the same. More particularly, the present invention relates to a window cover film including a base layer, a hard coating layer, and an anti-fingerprint layer, and a flexible display panel including the same.

A thermoplastic polymer advanceable by solid state polymerization is blended with at least one dissimilar thermoplastic polymer. The blend is solid state polymerized to provide a modified polymer alloy blend having at least one physical or chemical property different from that of the blend before solid state polymerization. The modified polymer alloy blend may be coextruded with a layer of thermoplastic extrusion polymer having a melt viscosity similar to that of the modified polymer alloy.

A thermally conductive type polyimide substrate is provided. The substrate comprises at least one insulating layer having a metal layer on a single side or both sides thereof. The material of the insulating layer is a thermally conductive type photosensitive resin having a thermal conductivity of 0.4 to 2, and the thermally conductive type photosensitive resin includes the following components: (a) a photosensitive polyimide, (b) an inorganic filler, and (c) a silica solution. The photosensitive polyimide accounts for 50 to 70% of a total weight of a solid composition of the thermally conductive type photosensitive resin. The inorganic filler accounts for 20-30% of the total weight of the solid composition of the thermally conductive type photosensitive resin, and has a particle size between 40 nm and 5 m. The silica solution comprises silica particles polymerized by a sol-gel process, and the silica particles have a particle size between 10 nm and 15 nm and account for 5 to 30% of the total weight of the solid composition of the thermally conductive type photosensitive resin.

A problem addressed by the present invention is to provide a low-friction member which does not easily lose low-friction properties thereof even when used for a relatively long period. The low-friction member LS according to the present invention is consisting of at least lubricating materials PL, PS and a polyimide resin MR. The low-friction member has a surface roughness Rsk or 0.500 or more and the surface exposure ratio of the lubricating materials of 15.0% or more. It is particularly preferred that the surface roughness Rsk be in a range of 0.0900 (inclusive) to 0.1400 (inclusive), and the surface exposure ratio of the lubricating materials be 35.0% or more. It is preferred that the lubricating materials be a fluororesin. The low-friction member thus has the property of not losing the low-friction properties thereof easily even when used for a relatively long period.

Provided is a heat-curable maleimide resin composition capable of being turned into a cured product with a superior dielectric property, and allowing a plating layer(s) to be formed only at laser-irradiated parts on the surface of or inside the cured product. The heat-curable maleimide resin composition contains: (A) a cyclic imide compound having, in one molecule, at least one dimer acid backbone, at least one linear alkylene group having not less than 6 carbon atoms, and at least two cyclic imide groups; and (B) a laser direct structuring additive being a metal oxide having a spinel structure and represented by the following average composition formula (1):

AB.sub.2O.sub.4 (1)

wherein A represents one or more metal elements selected from iron, copper, nickel, cobalt, zinc, magnesium and manganese, B represents iron or chrome, provided that A and B do not both represent iron.

A method for producing a device substrate by obtaining a laminate comprising a carrier substrate with a first polyimide film disposed on at least one surface of the carrier substrate, a second polyimide film disposed on the first polyimide film, applying a physical stimulus to the second polyimide film without causing chemical changes in the first polyimide film such that the adhesive strength of the first polyimide to the second polyimide film decreases and separating the second polyimide film from the first polyimide film formed on the carrier substrate to obtain the device.

In a first aspect, a polymer film includes a polyimide. The polyimide includes one or more dianhydrides and one or more diamines. Each of the dianhydrides and diamines is selected from the group consisting of crankshaft monomers, flexible monomers, rigid rotational monomers, rigid non-rotational monomers, and rotational inhibitor monomers. The polymer film has a D.sub.f of 0.005 or less, a water absorption of 2.0% or less and a water vapor transport rate of 50 (gmil)/(m.sup.2day) or less. In a second aspect, a metal-clad laminate includes the polymer film of first aspect and a first metal layer adhered to a first outer surface of the polymer film. In a third aspect, an electronic device includes the polymer film of the first aspect.

The present disclosure is directed to a base film having a chemically converted polyimide, a non-carbon black pigment and a particulate polyimide matting agent. The particulate polyimide matting agent is present in an amount from 1.6 to 9 weight percent of the base film.