A prepreg includes composition elements [A], [B], and [C] described below,

[A] a reinforcing fiber,

[B] a thermosetting resin, and

[C] a thermoplastic resin.

[B] contains a thermoplastic resin having an aromatic ring with an amount of 10% or more by mass, a resin region containing [B] is present on one surface of the prepreg, a resin region containing [C] is present on another surface of the prepreg, and [A] that crosses over a boundary surface between the resin region containing [B] and the resin region containing [C] and that is in contact with both resin regions is present.

A resin composition includes a polyphenylene ether resin of Formula (1) and an additive. The additive may include maleimide resin, unsaturated C═C double bond-containing crosslinking agent, polyolefin, flame retardant, filler, curing accelerator, or a combination thereof. An article is made from the resin composition. The article includes a prepreg, a resin film, a laminate or a printed circuit board and achieves improvements in one or more properties including comparative tracking index, breakdown voltage, dissipation factor and copper foil peeling strength.

##STR00001##

A polyimide film includes a polyimide in which a specific amount of molecular framework containing one or two silicon atoms in its main chain, wherein a total light transmittance measured in accordance with JIS K7361-1 is 85% or more; wherein a yellowness index calculated in accordance with JIS K7373-2006 is 30 or less; wherein a glass transition temperature is in a temperature range of from 150° C. to 400° C.; and wherein a tensile elastic modulus at 25° C. obtained by measuring a 15 mm×40 mm test piece at a tensile rate of 10 mm/min and a chuck distance of 20 mm in accordance with JIS K7127, is 1.8 GPa or more.

A fiber-reinforced thermoplastic resin filament is obtained by impregnating a continuous reinforcing fiber with a thermoplastic resin, and satisfies all of conditions (a) to (c). (a) The volume ratio of a reinforcing fiber in a fiber-reinforced thermoplastic resin filament is 30 to 80%; and the volume ratio of a thermoplastic resin in a fiber-reinforced thermoplastic resin filament is 70 to 20%. (b) The thickness of a fiber-reinforced thermoplastic resin filament is 0.01 to 3 mm. (c) The length of a filament contained in a fiber-reinforced thermoplastic resin filament is 1 m or more.

The polymer film according to an embodiment comprises at least one polymer resin selected from the group consisting of a polyamide-based resin, a polyimide-based resin, and a polyamide-imide-based resin, and has a haze of 0.6% or less and an in-plane retardation within a specific range for each wavelength band in the visible light region. The polymer film, which has an in-plane retardation within a specific range for each wavelength band in the visible light region, is excellent in transparency and optical properties, and it can remarkably reduce the rainbow phenomenon and improve the reflection appearance.

A method for ultra-hydrophilic surface treatment of a polymer fiber substrate according to the present invention comprises the steps of: forming a thermosetting coating layer on the surface of a polymer substrate; forming a carboxylate group (—COO—) on the surface of the thermosetting coating layer; forming an amide bond (—CONH—) between the thermosetting coating layer and hydrogel monomers; and forming a hydrophilic polymer layer by crosslinking the hydrogel monomers.

A polyimide film is a reaction product of a diamine component and an acid dianhydride component. The diamine component contains p-phenylenediamine, a first aromatic diamine, and a second aromatic diamine. The first aromatic diamine and the second aromatic diamine are different from each other and represented by the following formula (1):

##STR00001##

In the diamine component, each of a molar fraction of the p-phenylenediamine, a molar fraction of the first aromatic diamine, and a molar fraction of the second aromatic diamine is 10% by mole or more and 70% by mole or less. The acid dianhydride component contains an acid dianhydride containing an aromatic ring.

Provided is a space filling material having excellent strength in reinforcing a predetermined space to be filled with the space filling material and/or strength in fixing a material to be fixed therewith. The space filling material (11) includes reinforcing fibers and a thermoplastic resin, wherein the reinforcing fibers form a plurality of intersections at least a part of which are bonded with the thermoplastic resin, and among all of the reinforcing fibers, a proportion in volume of reinforcing fibers each having a bent ratio of 1.004 or higher is 20 vol % or more relative to a total volume of the reinforcing fibers, the bent ratio being defined as a ratio of fiber length/shortest distance between opposite ends of fiber. The space filling material (11) expands to fill a predetermined space (13) when the thermoplastic resin is softened by heating to release bending loads of the reinforcing fibers.

The present invention relates to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby and, particularly, to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby, wherein the polyimide-based film is useful as a cover substrate for a flexible electronic device since flexure characteristics thereof, represented by yield elongation, are excellent.

An embodiment can provide a polyamide-imide film, which has particular punching properties, is colorless and transparent and has excellent mechanical properties and optical properties, and a method for preparing same. The polyamide-imide film comprises a polyamide-imide polymer, which is formed by means of polymerizing an aromatic diamine compound, an aromatic dianhydride compound and a dicarbonyl compound, and satisfies the condition of general formula (1) below. General formula (1) 4≤X/Y≤12 X: the maximum hole diameter (mm) comprising cracks when the film is punched at 10 mm/min using a 2.5 mm spherical tip by means of a UTM compression mode Y: the modulus (GPa) of the film.