The present invention addresses the problem of providing a prepreg that yields a carbon fiber composite material that has exceptional tensile strength, heat resistance, and impact resistance and is suitable as a structural material of an aircraft body, wherein the resin composition used in the prepreg furthermore has exceptional viscosity stability, the prepreg containing a resin composition that contains carbon fibers and at least the constituent elements [A]—[D] as defined.

The present disclosure provides a unique method of making a fine fiber that is formed from a composition including an epoxy and a polymer component including a 4-vinyl pyridine-containing polymer. The present disclosure also provides a unique method of coating a fine fiber with a composition including an epoxy and a polymer component including a 4-vinyl pyridine-containing polymer. The present disclosure further provides fine fibers wherein the entirety of the fiber is formed from a composition including an epoxy and a polymer component including a 4-vinyl pyridine-containing polymer. Also provided are filter media and filter substrates including the fine fibers.

A hexagonal boron nitride powder having an average longer diameter (L) of primary particles in the hexagonal boron nitride powder of more than 10.0 μm and 30.0 μm or less, an average thickness (D) of the primary particles in the hexagonal boron nitride powder of 1.0 μm or more, a ratio of the average longer diameter (L) to the average thickness (D), [L/D], of 3.0 or more and 5.0 or less, and a content of primary particles having a ratio of a longer diameter (1) to a thickness (d), [l/d], of 3.0 or more and 5.0 or less of 25% or more, a method for producing the hexagonal boron nitride powder, and a resin composition and a resin sheet each containing the hexagonal boron nitride powder.

The present invention provides a prepreg for a coreless substrate and a coreless substrate and a semiconductor package using the prepreg, which can satisfy heat resistance, low thermal expansion, and bonding strength with a metal circuit at a level required for the coreless substrate. Specifically, the prepreg for a coreless substrate contains a thermosetting resin composition containing (a) dicyandiamide, (b) an adduct of a tertiary phosphine and quinones, (c) an amine compound having at least two primary amino groups, and (d) a maleimide compound having at least two primary amino groups having at least two N-substituted maleimide groups. Instead of (c) the amine compound having at least two primary amino groups and (d) the maleimide compound, having at least two N-substituted maleimide groups, (X) an amino-modified polyimide resin obtained by reacting them may be used.

A method for surface preparation of composite substrates prior to adhesive bonding. A curable surface treatment layer is applied onto a curable, resin-based composite substrate, followed by co-curing. After co-curing, the composite substrate is fully cured but the surface treatment layer remains partially cured. The surface treatment layer may be a resin film or a removal peel ply composed of resin-impregnated fabric. After surface preparation, the composite substrate is provided with a chemically-active, bondable surface that can be adhesively bonded to another composite substrate to form a covalently-bonded structure.

Provided is a prepreg including: a fiber layer containing unidirectionally arranged carbon fibers impregnated with a first thermosetting resin; and a resin layer disposed on at least one side of the fiber layer and containing a second thermosetting resin and a thermoplastic resin that is insoluble in the second thermosetting resin. The prepreg is configured such that the areal weight of fibers and the weight fraction of resin in the prepreg are 120 to 300 g/m.sup.2 and 25 to 50 mass %, respectively, and in the case where a plurality of prepregs are laid up, and the coefficient of interlayer friction is measured every 10° C. in a temperature range of 40 to 100° C. at a pull-out speed of 0.2 mm/min under a perpendicular stress of 0.8 bar, the temperature at which the coefficient of interlayer friction is 0.02 or less is present within a temperature range of 40 to 100° C. The prepreg exhibits high impact strength when formed into a fiber-reinforced plastic suitable for an aircraft structural member, and the prepreg also has excellent drapeability when a prepreg laminate is made to conform to a three dimensional shape.

A carbon fiber reinforced plastic structure has a low surface roughness and has reduced deformation due to residual stress, changes in temperature, etc., and a processing apparatus that uses the structure, are disclosed. The carbon fiber reinforced plastic structure (CFRP structure) includes a carbon fiber reinforced plastic member (CFRP member), and a resin layer formed on a first surface of the carbon fiber reinforced plastic member, the resin layer including an opposite surface that is opposite to a surface facing the first surface, the opposite surface having a surface roughness that is less than a surface roughness of the first surface of the carbon fiber reinforced plastic member.

A bilayer photonic crystal photoswitch thin-film device having the optical characteristics of both 2D and 3D photonic crystals, and a preparation method thereof are provided. When the bilayer photonic crystal photoswitch thin-film device is rotated periodically, different colors can be observed at a fixed rotation angle, that is, the device has the attribute of changing colors by means of rotation, and can thus realize the opening and closing of an optical path. The bilayer photonic crystal photoswitch thin-film new device has broad application prospects in the fields of photoswitches, optical waveguides, optical prisms, warming signs, anti-counterfeiting and information coding, etc.

A prepreg is provided that has excellent processability and handleability and that can be processed into a cured product with high heat resistance. Also provided is a method to produce such a prepreg in an industrially advantageous way without being restricted by the types and contents of the matrix resin components used. The prepreg includes at least components [A] to [D] as given below and a preliminary reaction product that is a reaction product of the component [B] and the component [C], at least one surface resin in the prepreg having a storage elastic modulus G′ in the range of 1.0×10.sup.3 to 2.0×10.sup.8 Pa as measured at a temperature of 40° C. and an angular frequency in the range of 0.06 to 314 rad/s: [A] carbon fiber, [B] epoxy resin, [C] curing agent, and [D] thermoplastic resin.

A high-performance composite material is provided including a polymer and a hybrid nanoadditive dispersed throughout the polymer at a low concentration and without agglomeration. The hybrid nanoadditive includes a first, graphene oxide portion and a second, polyhedral oligomeric silesquioxane (POSS) portion. Associated extrusion systems and methods are also provided.