A prepreg sheet (1) is formed by stacking a plurality of unit layers (10a, 10b) In the unit layers (10a, 10b), prepreg tapes (100), in which a reinforced fiber bundle is impregnated with a thermosetting matrix resin composition, are disposed in rows a plurality of times. One or more of the unit layers (10a, 10b) has a gap (G) between adjacent prepreg tapes (100), and the width thereof is 10% or less of the width of the narrower of the adjacent prepreg tapes (100).

A cured object and a method for producing the same are disclosed herein. In some embodiments, the method of producing a cured object includes introducing a resin composition including a resin and magnetic powder into one or more slots of a tubular object, wherein the resin composition includes a resin and a magnetic powder, wherein the tubular object includes a penetration space and an edge region having the one more slots formed therein, and wherein the penetration space and the one or more slots are formed in a longitudinal direction of the tubular object; inserting a solenoid coil into the penetration space of the tubular object; and generating a magnetic field with the solenoid coil to cure the resin present in the one or more slots of the tubular object.

The cured resin object can also have excellent withstand voltage characteristics.

A one-component thermosetting epoxy resin composition, including a) at least one epoxy resin A having on average more than one epoxide group per molecule; b) at least one latent hardener for epoxy resins; c) at least one physical or chemical blowing agent BA; d) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR1 with a Mooney Viscosity of 15-30 MU (Mooney units), based on the total amount of epoxy resin A; and e) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR2 with a Mooney Viscosity of 35-50 MU (Mooney units), based on the total amount of epoxy resin A. The ratio of ABR1 to ABR2 is from 0.5-2.0. The epoxy resin adhesive is notable for the improved storage stability.

The present invention relates to a method for producing a composite structure comprising a magnetic filler material embedded in a resin matrix. So far, a balance between sufficient magnetic performance and mechanical fatigue resistance, for applications involving cyclic strains of hundreds of thousands of cycles, has not been achieved, largely due to the poor compatibility between metallic and plastic surfaces. The present invention solves this problem by embedding magnetic filler material in a resin, after the magnetic filler material has been subjected to a possible surface treatment for improving the adhesion of the magnetic filler material to the resin matrix in the composite structure. Further, a composite structure comprising magnetic filler material embedded in a resin matrix obtainable by the method as disclosed in the current specification is disclosed. Still further, the use of the composite structure in applications requiring magnetic properties and resistance to mechanical fatigue is disclosed.

Thermosetting plastics are recycled by process that begins with grinding the plastic into small pieces. This particulate is then mixed with a catalyst and ball mill milled to a fine powder, which can then be reprocessed via molding (e.g., hot-press, injection, etc.).

A thermally expandable composition, including at least one epoxy-functional polymer, at least one thermoplastic polymer, at least one chemical blowing agent, and at least one activator, wherein the epoxy-functional polymer is present in the composition before expansion with an amount of between 30 and 75 wt.-%, based on the total composition, and the epoxy-functional polymer includes at least 300 mmol epoxy groups per kg polymer, and wherein the chemical blowing agent is able to form at least one reaction product with at least two amino groups upon thermal decomposition, and the chemical blowing agent is in the composition before expansion with an amount of between 5 and 30 wt.-%, based on the total composition.

A self-adhesive prepreg comprising a fibre reinforcement layer having a first side and a second side, wherein the first side of the fibre reinforcement layer has been pre-impregnated with a self-adhesive resin composition. The self-adhesive may be used as a structural reinforcement and is especially adapted for direct bonding to oily steel or galvanized steel in the automotive, aerospace and other sheet metal fabrication industries.

Provided is an insulating varnish composition, including: two or more kinds of epoxy resins; and a filler having an average primary particle diameter of 500 nm or less, wherein the two or more kinds of epoxy resins contain 80 mass % or more of an epoxy resin having a number of repetitions of 0 in a molecular structural formula thereof with respect to a total mass of the two or more kinds of epoxy resins.

Various embodiments include an impregnation formulation for a wrapping tape insulation of an electrical machine. The formulation comprises: a resin formulation with an epoxy base resin and a first component; and a hardener formulation with a hardener. The resin formulation reacts when combined with the hardener formulation to produce an insulation material. The first component includes a saturated and/or unsaturated epoxycycloalkyl group. A glass transition temperature of the insulation material is elevated compared to an impregnation formulation without the first component.

A prepreg contains components [A] to [E], wherein 85% by mass or more of the component [E] is present in a range within 9% of the average thickness of the prepreg from each surface of the prepreg, and a range within 7% of the average thickness of the prepreg from each surface of the prepreg is composed of a first resin composition containing components [B] to [E]. [A] a carbon fiber, [B] an epoxy resin having two or more glycidyl groups in one molecule, [C] an aromatic amine compound, [D] a thermoplastic resin having a polyarylether skeleton, and [E] particles having a number average primary particle size of 5 to 50 μm, having a content ratio (% by mass) of thermoplastic resin and thermosetting resin of 95:5 to 70:30.