Method for preparing carbon fiber precursor

Abstract

Disclosed is a method for preparing a precursor fiber for a carbon fiber. The precursor fiber of fine denier according to the present invention is used to prepare a carbon fiber having excellent tensile strength and compressive strength by a conventional single component spinneret using a superdrawing process to prepare a high strength and high elastic carbon fiber with a reduction in stabilization time.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2011-0122476 filed Nov. 22, 2011, the entire contents of which are incorporated herein by reference.BACKGROUND[0002](a) Technical Field[0003]The present invention relates to a method for preparing a precursor fiber for a carbon fiber. More particularly, it relates to a method for preparing a precursor fiber of fine denier used to prepare a carbon fiber having excellent tensile strength and compressive strength by a conventional single component spinneret using a superdrawing process, thereby preparing a high strength and high elastic carbon fiber with a reduction in stabilization time.[0004](b) Background Art[0005]Carbon fiber is a high strength (e.g., 3 to 7 GPa) and highly elastic (150 to 950 GPa) fiber containing more than 92% carbon and can be prepared by heat-treating a precursor material with a high carbon yield at a fairly high temperatur...

AI Technical Summary

Benefits of technology

The present invention provides a method for making a precursor fiber for carbon fiber that has excellent properties by spinning a fiber and then using a superdrawing process to prepare a fiber of fine denier. This method can produce a carbon fiber with excellent tensile strength and modulus by reducing the diameter of an as-spun fiber. Additionally, it can create a fiber with excellent molecular orientation and reduced diameter, leading to a high strength and stiffness carbon fiber using a superdrawing process.

Problems solved by technology

The degradation temperature of the acrylonitrile polymer is lower than the melting temperature, and thus it is difficult to perform melt-spinning.

ccurs. During the stabilization and carbonization processes, fiber contraction in the longitudinal direction occurs due to physical or chemical causes, which may reduce the molecular orientation of the finally obtained carbon

A spinneret with a relatively smaller hole is required to prepare a precursor fiber having a small diameter and, in particular, an expensive multi-component spinning machine, which can separate a desired fiber through a physical process (e.g., side-by-side fiber) or a chemical process (e.g., a islands-in-a-sea fiber) by simultaneously spinning at least two polymers, is required to prepare a superfine fiber.

This method, however, has problems in that a process of melting or incinerating auxiliary components after the spinning as well as an expensive composite spinning machine significantly increases the manufacturing costs.

However, in these techniques, it is difficult to freely control the cross-sectional area of the fiber while achieving mechanical properties as the carbon fiber precursor.

However, these techniques are to conduct superdrawing to modify the fiber, and the prepared fiber has too low of a carbon yield to be used as the carbon fiber precursor.

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