To provide a carbon fiber bundle capable of exhibiting good interfacial adhesion to a polyolefin-based resin, especially, to a polypropylene resin.
This carbon fiber bundle has a plurality of single fibers, wherein each of the single fibers has a plurality of wrinkles on its surface so that a difference of elevation between a highest part and a lowest part of the wrinkles is not less than 40 nm in a region surrounded by sides having a length of 2 μm in the circumferential direction of the fiber and sides having a length of 1 μm in the longitudinal direction, and the carbon fiber bundle is subjected to sizing treatment with a sizing agent containing a polymer of which the main chain is formed out of carbon-carbon bonds and which has acid groups in at least a part of the side chains or at least a part of terminals of the main chain and an acid value of 23-120 mgKOH/g, when measured according to ASTM D1386, or containing a polymer of which the main chain is formed out of the carbon-carbon bonds and which has at least any one kind of epoxy groups and ester groups in at least a part of the side chains or at least a part of terminals of the main chain.
FUKUSHIMA AKIHIKO
FUJIE SHINOBU
Nobuyuki Kaneda
Katsuhiro Ito
Ishibashi Masayuki