METHOD FOR PRODUCING REINFORCED CARBON COMPOSITE BASED ON POWDER BINDER CONTAINING SOLID EPOXY RESIN AND BIFUNCTIONAL BENZOXAZINE (EMBODIMENTS) Russian patent published in 2024 - IPC C08J5/24 

FIELD: composite materials.

SUBSTANCE: invention relates to methods for producing reinforced carbon composite based on a powder binder and can be used in production of items from polymer composite materials used in instrument making, automotive, aviation, aerospace, electrical engineering, construction, and other industries. The first method for producing a reinforced carbon composite based on a powder binder containing 100 parts by weight of solid epoxy resin and 40-100 parts by weight of bifunctional benzoxazine is as follows: at the 1st stage, a powder binder is obtained, for which 100 parts by weight of epoxy resin and 40-100 parts by weight of bifunctional benzoxazine are taken, mixed and ground until a homogeneous powder is obtained; the resulting mixture is extruded in a twin-screw mixer at the temperature of 70 °C – zones I and II, 100 °C – zone III; the resulting extruded granules are crushed to particles no larger than 100 mcm in size; at the 2nd stage, a reinforced carbon composite is obtained, for which the powder binder obtained at the 1st stage is applied in an electrostatic field on one or both sides to the carbon fabric mounted on a conductive frame. After application, the fabric is heated to the temperature of 100 °C, the binder melts and impregnates the fabric due to low surface tension of the binder melt with an electrostatic charge on the surface; the resulting impregnated sheets of fabric are collected in a technological bag and placed in a vacuum bag. Then vacuum is created with a residual pressure of 50 mbar in the technological bag, and then temperature starts to increase to 120 °C; then the technological bag is cooled, a consolidated plate is obtained, it is removed and used to produce an item by thermoforming between the matrix and the punch of the mould heated to the temperature of 250 °C. The second method differs from the first in that, at the 2nd stage, the powder binder is applied in an electrostatic field on one side to the carbon fabric laid out on metal equipment, and melting is carried out using an IR lamp; then laying out and spraying subsequent layers with melting of the binder; the carbon fabric is cut according to the cutting map, which ensures maximum utilization of the material, a vacuum bag is assembled and a vacuum is created with a residual pressure of 50 mbar in the technological bag, and then stepwise temperature increase to 200 °C is started. Then the technological bag is cooled, the composite product is removed and placed in an oven for heat treatment at 250 °C for at least 1 hour.

EFFECT: development of a powder binder based on a benzoxazine composition and a method for producing a reinforced carbon composite based on it (options), allowing to eliminate the use of solvents when producing prepregs and to eliminate long-term high-temperature heating of the binder when producing prepregs.

2 cl, 2 dwg, 16 ex