Patent ID: 6228473
Filing Date: 2001-05-08
Classification: B29C,B32B,Y10T

Abstract:
A carbon fiber-reinforced composite material having carbon fibers aligned nearly parallel to the longitudinal direction, wherein the carbon fibers have a tensile elastic modulus of 5 to 160 GPa, a strain at compressive break of 1.7 to 5%, and a density of 1.5 to 1.9 g/cm.sup.3 and further the composite comprising said carbon fibers exhibits a mode I interlayer fracture toughness G.sub.IC (at 5% offset in accordance with JIS K 7086) of 0.15 to 4.5 kJ/m.sup.2, a mode II interlayer fracture toughness G.sub.IR (at propagation in accordance with JIS K 7086) of 0.20 to 5 kJ/m.sup.2, a mode II interlayer fracture toughness G.sub.IIC (at 5% offset in accordance with JIS K 7086) of 0.45 to 9.5 kJ/m.sup.2, and a mode II interlayer fracture toughness G.sub.IIR (at propagation in accordance with JIS K 7086) of 0.5 to 10 kJ/m.sup.2, and the composite produces no delamination by an impact energy of less than 1.4 J/mm in the test of compression after impact in accordance with JIS K 7089.