PREPREG AND METHOD OF ITS PRODUCTION Russian patent published in 2020 - IPC C08J5/24 B32B5/28 B32B27/04 

FIELD: production of composite materials.

SUBSTANCE: invention relates to a prepreg and a method for production thereof and is intended for making reinforced plastics. Prepreg contains a layer of fibers containing unidirectional carbon fibers impregnated with the epoxy resin composition. Prepreg comprises a layer of resin existing on both sides of the layer of fibers, comprising epoxy resin and polyamide particles, insoluble in epoxy resin, and a layer located between the resin layer and the fiber layer and containing the solid resin. Prepreg comprising carbon fibers having a fiber areal weight of 120 to 300 g/m², and the resin has a weight fraction of 25 to 50 wt %; and where frequency of extreme values of surface geometry along straight line, perpendicular to prepreg fibers, is 30 points/mm or less, when prepreg for 24 hours is exposed to temperature, at which coefficient of interlayer friction is the least; where, using the prepreg sheets stacked, the coefficient of inter-ply friction of the prepreg is measured at intervals of 10 °C in the temperature range of 40 to 80 °C under conditions of: drawing speed of 0.2 mm/min, perpendicular to voltage of 0.1 bar and displacement at pulling of 1 mm.

EFFECT: prepreg is suitable for aircraft structural elements, has high impact strength in form of fiber-reinforced plastic and has excellent drapability, when formed into layered prepreg, to which corresponding three-dimensional shape is attached.

8 cl, 4 dwg, 2 tbl, 1 ex