Provided are an epoxy resin including: an epoxidized product of monoalkyl dihydroxybenzene; and a compound that is detected in the molecular weight range from a molecular weight at the peak top of the epoxidized product of the monoalkyl dihydroxybenzene to the molecular weight at the peak top+20 to 40 and has a peak area % of 0.1% to 0.8% in a GPC chart, and an epoxy resin including an epoxidized product of monoalkyl catechol in which the ratio of the total content of a cyclic compound having a cyclic structure that has two adjacent oxygen atoms derived from the monoalkyl catechol as constituent atoms and a monoglycidyletherified product of the monoalkyl catechol to the content of a diglycidyletherified product of the monoalkyl catechol is in the range of 0.10 to 0.40 as measured by high performance liquid chromatography.

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 resin component, polyethersulfone as a toughening agent, a thermoplastic particle component, a nanoparticle component and a curing agent.

This invention relates to a resin composition. The resin composition comprises a first polyfunctional epoxy component (i) comprising an epoxy resin based on a alkylol alkane triglycidyl ether monomer, and a second component, (ii) comprising an epoxy resin. The composition further comprise a third component, (iii) comprising a hydrazide based curative in combination with either (a) a urone based curative or (b) an imidazole based curative or both.

Provided are a method for producing an FRP precursor and a device for producing an FRP precursor, wherein the method and the device have a good productivity, and under a normal pressure, enable filling of a resin into a bulk gap of an aggregate as well as prevent the resin from spouting out from an edge portion thereof. The method for producing the FRP precursor is to produce the FRP precursor by melt-adhering each of a pair of thermosetting resin films 54 to each of both surfaces 40a and 40b of an aggregate 40 that is in a form of a sheet, the method comprising: an aggregate's surface heating process to heat aggregate's both surfaces, i.e., the both aggregate's surfaces 40a and 40b of the aggregate 40, and a film press-adhering process to obtain the FRP precursor wherein under a normal pressure, one aggregate-side film surface 54a of the pair of the films 54 is press-adhered to one surface of the heated both aggregate's surfaces, and another aggregate-side film surface 54a of the pair of the films 54 is press-adhered to another surface of the heated both aggregate's surfaces.

A prepreg having at least one layer of fibres and a curable thermosetting resin system at least partly impregnating the at least one layer of fibres, wherein the curable thermosetting resin system includes a curable thermosetting resin including at least two epoxide groups, a curing agent that includes at least one amine group, and an accelerator that includes an azole group; wherein the curable thermosetting resin, the curing agent and the accelerator are provided in respective concentrations in the prepreg to provide that, after curing the thermosetting resin at a cure temperature of at least 140 C. for a period of from 1 to 6 minutes, (i) the cured thermosetting resin has a glass transition temperature Tg which is greater than the cure temperature and is within the range of from 150 C. to 180 C. and (ii) the cured thermosetting resin is at least 90% cured.

A prepreg tape in which reinforcing fiber bundles are impregnated with a thermosetting resin composition, wherein the prepreg tape has a tack value measured at 23 C. at a plunger push pressure of 90 kPa of 5-40 kPa, a tack value measured at 45 C. and a plunger push pressure of 150 kPa of 35-100 kPa, and a drape value at 23 C. of 10-40, and includes unidirectional fibers arranged along the direction of length of the prepreg tape.

The present invention relates to rapid-curing resin formulations as well as fiber-reinforced composite materials comprising the same and their use in the manufacture of molded articles, particularly where the manufacturing process requires high throughput and where resin formulations having consistent handling characteristics (e.g., tack and flexibility) would be preferable across normal to elevated laminating environments (as defined by temperatures between 20 C. and 60 C.). The present invention further relates to a manufacturing process for preparing an article, particularly a molded article, from a fiber-reinforced composite material comprising a rapid-curing resin formulation.

The thermosetting resin composition according to an embodiment of the present invention contains a component (A) which is a novolac vinyl ester resin having a hydroxyl group and an ethylenically unsaturated group in the molecule, a component (B) which is an ethylenically unsaturated monomer, and a component (D) which is a polyisocyanate compound, wherein the component (A) has a hydroxyl value of 30-150 mgKOH/g, and the mole number of the hydroxyl group with respect to the mole number of the ethylenically unsaturated group per gram of the component (A) ((the amount of the hydroxyl group [mol/g])/(the amount of the ethylenically unsaturated group [mol/g])) is 0.1-0.8.

The present invention addresses the problem of providing a prepreg that has excellent short-time and low-pressure handling properties, during pasting and layering work. In order to solve the problem, this invention has the following configuration. The prepreg includes reinforcing fibers and an epoxy resin composition, has a fiber content of 90 mass % or less, and satisfies conditions (a) and (b) below. (a) When the average thickness of the prepreg is set as D (D being 3 m or greater), the viscosity at 25 C. of the epoxy resin composition at a site (I) located at a depth of D/4 to 3D/4 from the surface on one side of the prepreg is 50,000 to 300,000 Pa.Math.s inclusive. (b) From among sites (II) located at a depth of up to 0.5 m from each surface on both sides of the prepreg, the viscosity at 25 C. of the epoxy resin composition at least at a site (II) on the one side is 10,000 to 40,000 Pa.Math.s inclusive.

Composite honeycomb that may be contoured to form composite honeycomb structures, which have tight radii of curvatures and/or compound curvatures, and which are suitable for use in high temperature environments. The method for making the composite honeycomb involves using high temperature prepreg to make a flexible composite honeycomb that is formed into a composite honeycomb precursor. A high temperature coating resin is applied to the composite honeycomb precursor to form the high temperature composite honeycomb.