CARBON FIBER BUNDLE, ITS PRODUCTION METHOD, PREPREG AND COMPOSITE MATERIAL REINFORCED WITH CARBON FIBER Russian patent published in 2022 - IPC D01F9/22 B29B11/16 

FIELD: composite materials.

SUBSTANCE: invention relates to a carbon fiber bundle, which is used in sports fields of application, such as golf clubs and fishing rods, and to its production method, prepreg, and composite material reinforced with carbon fiber, obtained using the carbon fiber bundle. In the carbon fiber bundle, the ratio between a crystallite size Lc (nm), compressive strength of single fiber Fc (GPa), measured by a fragmentation method, when compressing composites containing fiber of one type, and an initial elasticity module E₀ (GPa), when testing tensile strength of resin-impregnated thread, simultaneously satisfies following formulas (1)-(3), and Lc has a value of 2.60 nm or more and 4.00 nm or less: Fc ≥ 1.3 × 10/Lc - 0.3 (1); E₀ ≤ 80 × Lc + 155 (2); E₀ ≥ 330 (3).

EFFECT: obtained carbon fiber bundle simultaneously shows high compressive strength of composite material reinforced by carbon fiber and high elasticity module, when tensioning thread of the carbon fiber bundle.

11 cl, 1 dwg, 3 tbl, 15 ex