US 2007/0183960 A1 · Carbon fiber precursor fiber bundle, production method and production device therefor, and carbon fiber and production method therefor

Abstract

There are provided a carbon fiber precursor fiber bundle which permits easy bundling of a plurality of small tows into one bundle, is provided with a dividing capability to divide into the original small tows spontaneously at the time of firing, and is suitable for obtaining a carbon fiber that is excellent in productivity and quality, and a production method and a production apparatus of the carbon fiber precursor fiber bundle, and an excellent carbon fiber and a production method thereof. A carbon fiber precursor fiber bundle that has a degree of intermingle of 1 m−1 or less between small tows, consists of substantially straight fibers without imparted crimp, a tow of which straight fibers has a moisture content of less than 10% by mass when housed in a container, and has a widthwise dividing capability to maintain a form of a single aggregate of tows when housed in a container, taken out from the container and guided into a firing step, and to divide into a plurality of small tows in the firing step by the tension generated in the firing step. A production method thereof. A production apparatus of a carbon fiber precursor fiber bundle, comprising an intermingling device that comprises a yarn channel having a flat rectangular section through which a plurality of small tows can pass in a manner adjacent to each other and a plurality of air jet holes disposed with predetermined intervals along the long side direction of the flat rectangle and having the openings thereof in the yarn channel. A carbon fiber using the precursor fiber bundle and a production method thereof.

Claims30

Dependent claims

A carbon fiber precursor fiber bundle, characterized by:

having 1 m−1 or less of a degree of intermingle between a plurality of small tows based on the hook drop method;
consisting of substantially straight fibers without imparted crimp, a tow of which straight fibers has a moisture content of less than 10% by mass when housed in a container;
and
having a widthwise dividing capability to maintain a form of a single aggregate of tows when housed in a container, taken out from the container and guided into a firing step, and to divide into a plurality of small tows in the firing step by the tension generated in the firing step;

1 more element

A production method of a carbon fiber precursor fiber bundle, characterized by comprising:

a coagulation step of forming swollen yarn by extruding an organic solvent solution of an acrylonitrile-based polymer into an aqueous solution of dimethylacetamide from a spinning nozzle having a nozzle hole diameter of 45 μm or more and 75 μm or less and the number of holes of 50,000 or more at a coagulated yarn take-up speed/extrusion linear speed ratio of 0.8 or less;
a wet heat drawing step of wet heat drawing the swollen yarn;
an oiling agent imparting step of imparting a first oiling agent to the wet heat drawn yarn by guiding the heat wet drawn yarn into a first oil bath, and subsequently imparting a second oiling agent in a second oil bath after once squeezing the yarn by use of two or more guides;
a small tow production step of obtaining a small tow by drying, densifying and secondarily drawing the yarn imparted with the first and second oiling agents so as to have a total drawing magnification of 5 or more and 10 or less;
and
an aggregate-of-tows production step of obtaining an aggregate of tows by feeding a plurality of the small tows so as to be in parallel and adjacent to each other into an intermingling device that comprises a yarn channel having a flat rectangular section and a plurality of air jet holes which are disposed with a predetermined interval along the long side direction of the flat rectangle and which open into the yarn channel, and by jetting out air from the air jet holes to intermingle the adjacent small tows with each other.

3 more elements

Dependencies are inferred from the claim text.

Carbon fiber precursor fiber bundle, production method and production device therefor, and carbon fiber and production method therefor

Life of this patent

Carbon fiber precursor fiber bundle, production method and production device therefor, and carbon fiber and production method therefor

Life of this patent

Abstract

Claims30