Patent ID: 8124228
Filing Date: 2012-02-28
Classification: D01F,D02J,Y10T

Abstract:
1. A carbon fiber strand comprising of a bundle of 20,000 to 30,000 carbon fibers, each of which has in the surface thereof, a plurality of creases parallel to the fiber-axis direction of the carbon fiber and in which as measured by scanning probe microscopy, an inter-crease distance in the surface of said carbon fiber is 100 to 119 nm, a crease depth in the surface is 23 to 30 nm, an average fiber diameter is 4.5 to 6.5 μm, a specific surface area is 0.6 to 0.8 m 2 /g and a density is 1.76 g/cm 3 or more, wherein said carbon fiber strand has a strand tensile strength of 5,650 MPa or more and a strand tensile modulus of 300 GPa or more; a strand wound with a predetermined tension has a strand width of 5.5 mm or more; and no strand splittings are observed in a strand splitting evaluation method where a predetermined tension is applied to a running carbon fiber strand.