The present invention aims at providing a prepreg for producing a laminate suitable as a structural material, and a laminate, which have excellent tensile shear joining strength, fatigue joining strength, and interlaminar fractural toughness values, and can be firmly integrated with another structural member by welding. The present invention is a prepreg including the following structural components [A], [B], and [C], wherein [C] is present on a surface of the prepreg, [C] is a crystalline thermoplastic resin having a glass transition temperature of 100° C. or higher or an amorphous thermoplastic resin having a glass transition temperature of 180° C. or higher, and the reinforcing fibers [A] are present which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas: [A] reinforcing fibers; [B] a thermosetting resin; and [C] a thermoplastic resin.

The present invention provides a curable composition containing a urethane-modified epoxy resin (A) as an essential component of a main agent and an acid anhydride (B) as an essential component of a curing agent, the urethane-modified epoxy resin (A) being a reaction product obtained by using a polyisocyanate compound (a1), a polyether polyol (a2), and a hydroxy group-containing epoxy resin (a3) as essential reaction materials; a cured product thereof; a fiber-reinforced composite material; a fiber-reinforced resin molded article; and a method for producing a fiber-reinforced resin molded article. The curable composition can form a cured product having excellent fracture toughness and tensile strength in the cured product.

A method of increasing the glass transition point of a cured epoxy comprising a bisphenol A diglycidyl ether and a polyetheramine includes the step of including 1,8-diamino-p-menthane as an additional hardener for curing the epoxy. An epoxy formulation includes bisphenol A diglycidyl ether and a hardener including a polyetheramine and 1,8-diamino-p-menthane.

A circuit build-up film for wafer-level packaging (WLP) includes 40 to 60 parts by mass of a first epoxy resin, 15 to 30 parts by mass of a second epoxy resin, 25 to 50 parts by mass of a curing agent, 0.1 to 5 parts by mass of a curing accelerator, 5 to 20 parts by mass of an additive, 320 to 650 parts by mass of an inorganic filler, and 0.01 to 5 parts by mass of a silane coupling agent (SCA), where the additive is obtained by subjecting an epoxy resin to a reaction with a polyhydroxyl-terminated dendritic crosslinking agent. The build-up film shows prominent fluidity during heating and curing, and can completely fill gaps among wafers. A packaging process using the build-up film is simple. Regardless of the number of wafers, packaging can be completed through one procedure with the build-up film.

An apparatus for mixing two or more substances, the apparatus comprising: (a) a first surface, the first surface having a first profile, (b) a second surface spaced apart from the first surface, the second surface having a second profile, (c) a mixing gap formed between the first and second profiles of the first surface and the second surface, and (d) at least one input channel in liquid communication with the mixing gap, to feed the mixing gap with the two or more substances to be mixed.

Provided is a resin composition that has satisfactory impregnability into reinforcing fibers due to low viscosity and small viscosity increase even in an impregnation process performed for a long time. The resin composition being suitable as a matrix resin for a fiber-reinforced composite material for producing a cured molded article that has toughness and fatigue resistance. The resin composition for a fiber-reinforced composite material includes an epoxy resin, an acid anhydride-based curing agent, an imidazole-based curing accelerator, a radically polymerizable monomer, and a radical polymerization initiator as essential components, has a viscosity at 25° C. that falls within a range of 50 mPa.Math.s to 800 mPa.Math.s as measured by an E-type viscometer, and exhibits a viscosity increase ratio of 200% or less after 8 h at 25° C., wherein 50% by mass or more of the acid anhydride-based curing agent is an alicyclic acid anhydride having no olefinic unsaturated bond.

A prepreg which is suitable for producing a fiber-reinforced composite material in a short period of time without using an autoclave, can produce a fiber-reinforced composite material in which the occurrence of voids is suppressed and excellent impact resistance is achieved, and has excellent handling properties; and a fiber-reinforced composite material using the prepreg. This prepreg is a prepreg in which a reinforcing fiber [A] arranged in layers is partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a curing agent [C], wherein the impregnation rate φ is 30-95%, and a thermoplastic resin [D] insoluble in the epoxy resin [B] is unevenly distributed on both surfaces of the prepreg. In addition, in the layers of the reinforcing fiber [A], epoxy resin composition-unimpregnated portions are localized on one surface of the prepreg, and the localization parameter a, which defines the degree of localization, is in the range of 0.10<σ<0.45.

The objective of the present invention is to provide a prepreg and a fiber reinforced composite material using this prepreg. This prepreg has good handleability, is suitable for producing a reinforced composite material in a short-time and without using an autoclave, and is capable of yielding a fiber reinforced composite material exhibiting excellent impact resistance, wherein the occurrence of voids has been suppressed. To attain the objective, this prepreg comprises a reinforced fiber [A] that is layered and partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a hardener [C], the impregnation rate φ being 30 to 95%. In this prepreg, a thermoplastic resin [D] insoluble in the epoxy resin [B] is distributed unevenly over a surface on one side of the prepreg, and a portion not impregnated with the epoxy resin composition is localized in the layer of the reinforced fiber [A] on the side where the thermoplastic resin [D] is distributed unevenly. This prepreg has a localization parameter σ, which defines the degree of the localization to be in the range of 0.10<σ<0.45.

Embodiments of the present invention disclose a method for limiting peak exotherm temperatures in epoxy systems comprising the step of: combining an amine hardener, an epoxy and a diluent to form an epoxy system, wherein the diluent is selected from the group consisting of: ethylene carbonate, propylene carbonate, butylene carbonate, delta-valerolactam, delta-valerolactone, gamma valerolactone, butyrolactam, beta butyrolactone, gamma butyrolactone, and combinations thereof.

The present invention provides thermosetting resin pre-impregnated or infused fiber materials or prepregs comprising a thermosetting resin mixture and a fiber material component of a heat resistant fiber, such as carbon fiber, having an areal weight of from 500 to 3,000 g/m2 having a coating of from 0.5 to 4 phr of a latent, particulate curative or solid curative, preferably, dicyandiamide, wherein the prepregs are infused with a thermosetting resin mixture comprising (a) at least one liquid epoxy resin, and (b) a hardener and/or a catalyst, as well as methods of making the same. The prepregs of present invention enables the simple provision of lightweight composites having consistent resin cure throughout.