The present disclosure provides an organic sulfur acid-free composition containing a benzoxazine, phenolic compound and nitrogen-containing heterocyclic compound. The organic sulfur acid-free composition, upon curing at temperatures as low as 130-140 C., renders void free cured articles having well balanced thermal, chemical and mechanical properties. The organic sulfur acid-free composition may be used in a variety of applications, such as in coatings, structural and non-structural composites and encapsulating systems for electronic and electrical components.

Pre-impregnated composite material (prepreg) that can be cured/molded to form aerospace composite parts. The prepreg includes carbon reinforcing fibers and an uncured resin matrix. The resin matrix includes an epoxy component that is a combination of a hydrocarbon epoxy novolac resin and a trifunctional epoxy resin and optionally a tetrafunctional epoxy resin. The resin matrix includes polyethersulfone as a toughening agent and a thermoplastic particle component.

Pre-impregnated composite material (prepreg) that can be cured/molded to form aerospace composite parts. The prepreg includes carbon reinforcing fibers and an uncured resin matrix. The resin matrix includes an epoxy component, polyethersulfone as a toughening agent, and a curing agent. The resin matrix is also composed of a thermoplastic particle component that includes hybrid polyamide particles wherein each hybrid particle contains a mixture of amorphous and semi-crystalline polyamide.

Provided are a printed circuit board in which warps are effectively suppressed, and a semiconductor package having a semiconductor device mounted on said printed circuit board, even though circuit patterns of different amounts of metal are formed on both sides of one cured product of a prepreg. Specifically, said printed circuit board is a printed circuit board which comprises a cured product of a prepreg comprising a fiber base material and a resin composition, in which circuit patterns of different amounts of metal are formed on both sides of one cured product of the prepreg, in which said prepreg has layers on the front and back of said fiber base material, wherein said layers comprise resin compositions having different heat curing shrinkage rates, in which among these layers, the layer made of the resin composition having a smaller heat curing shrinkage rate is present on the side on which the circuit pattern with a smaller amount of metal is formed.

A reinforcing fiber fabric substrate has a binder containing a thermosetting resin [A] and a curing catalyst [B] at a basis weight of 0.1 g/m2-4 g/m2 on at least the surface of a reinforcing fiber fabric constructed of reinforcing fiber strands, wherein the reinforcing fiber fabric substrate has a heating temperature (T) in the 80-180 C. range, and the adhesive strength becomes 0.5 N/25 mm or higher at the heating temperature (T) between preform layers molded by laminating this reinforcing fiber fabric substrate at the heating temperature (T).

The purpose of the present invention is to provide a prepreg which satisfies one of a)-c): a) having superior storage stability and capable of providing a fiber-reinforced composite material having superior mechanical properties; b) capable of providing a fiber-reinforced composite material having superior mechanical properties, and the obtained fiber-reinforced composite material has superior appearance quality; and c) having superior storage stability, generating less amount of heat when cured, and enabling the cure extent and the viscosity in the B-stage state to be flexibly controlled. To achieve the purpose, the present invention provides a prepreg including reinforced fibers and an epoxy resin composition which contains an epoxy resin and a curing agent represented by a specific chemical formula, and which satisfies a specific condition.

The present invention provides curable moldable compositions comprising from 10 to 80 volume % of heat resistant fiber compositions, a two component resin mixture of (i) one or more epoxy resins, and (ii) a hardener comprising a combination of triethylenetetraamine (TETA) and from 3 to 15 wt. %, based on the weight of the TETA, of 2-phenylimidazole (2-PI). The compositions cure to provide composite articles having a short demold time of 90 s or less at 130 C. and 101 kPa and a high DSC glass transition temperature (Tg) of from 130 to 180 C. when cured at 130 C. for 90 seconds at a pressure of 101 kPa. The invention enables lightweight, heat resistant composite articles, such as for use in automotive applications.

A glass cloth comprising a glass yarn woven together, the glass yarn comprising multiple glass filaments, wherein an amount of B.sub.2O.sub.3 in a composition of the glass filaments is 15% by mass to 30% by mass, an amount of SiO.sub.2 in the composition thereof is 45% by mass to 60% by mass, and an amount of P.sub.2O.sub.5 in the composition thereof is 2% by mass to 8% by mass, and loss on ignition (LOI) of the glass cloth is 0.90% by mass to 2.0% by mass.

The prepreg includes a first resin layer and a second resin layer disposed on both surfaces of the first resin layer. The first resin layer is a half-cured product of a first resin composition that includes a glass cloth impregnated with the first resin composition and contains no hexagonal boron nitride. The second resin layer is a half-cured product of a second resin composition containing hexagonal boron nitride. The glass cloth has a warp and weft weave density of 54 pieces/25 mm or more. The hexagonal boron nitride has an average particle size ranging from 10 m to 30 m. The hexagonal boron nitride is contained in an amount ranging from 20 parts by mass to 40 parts by mass relative to 100 parts by mass of a residual component other than the hexagonal boron nitride in the second resin composition.

Provided are an encapsulation film, an organic electronic device comprising the same, and a method of manufacturing the organic electronic device. When the organic electronic device is encapsulated using the encapsulation film, an excellent moisture barrier property may be realized, and as reflection or scattering of light is prevented by absorbing and blocking internal or external light, external defects of the organic electronic device may be prevented.