Method of manufacturing carbon fiber with thick denier

摘要

The present invention relates to a method for producing carbon fibers having a monofilament fineness of 1 to 2 denier in which a thick denier polyacrylonitrile-based precursor fiber for carbon fibers having a monofilament fineness of 2 to 4 denier is produced by using a spinning solution containing a polyacrylonitrile-based polymer and a conductive carbon material, and a chlorination treatment and a carbonization treatment are performed on the polyacrylonitrile-based precursor fiber for carbon fibers to produce the carbon fibers having a monofilament fineness of 1 to 2 denier. The present invention relates to carbon fibers having a monofilament fineness of 1 to 2 denier and whose fiber fineness is relatively higher than the monofilament fineness of the conventional carbon fibers such that the productivity of the carbon fibers is greatly improved. The thick denier polyacrylonitrile-based precursor fiber for carbon fibers of the present invention has a monofilament fineness of 2 to 4 denier and contains a conductive carbon material such that the difference (difference of chlorination) in thermal stability between the inside and the outside of the precursor fiber is minimized when the chlorination treatment is carried out. In other words, uniform thermal stabilization (chlorination) occurs both inside and outside of the precursor fiber, resulting in a large number of pores in the carbon fibers during the production of the same, thereby effectively preventing the problem of increasing cut-off rates and deteriorated mechanical properties.