US 6,635,199 B2 · Process for producing a precursor fiber bundle and a carbon fiber bundle

Abstract

A separable tow of elongated polymeric filaments comprises a plurality of distinct sub-tows lightly and individually and separably joined, as by light crimping together along their edges or, if uncrimped, joined by presence of moisture, and capable of being packed into a container and later removed and separated. The filaments are preferably acrylic and have a total fineness of about 300,00-1,500,000 denier and the sub-tows each of which has a total fineness of about 50,000-250,000 denier, with a filament fineness of about 1-2 denier, and each sub-tow has a degree of entanglement of about 10-40 m−1 as measured by the hook drop test. The separable tow is made of a plurality of sub-tows, after separately drawing the sub-tows and subsequently removably joining the sub-tows into a single tow.

Claims9

Dependent claims

A process for producing a precursor fiber bundle from multifilaments spun from a spinnerette comprising forming a group comprising a plurality of sub-tows each of which is separated from each other, drawing said sub-tows while separated from each other;

collecting said drawn sub-tows and combining them into a single tow capable of being divided into said plurality of sub-tows;
and packing said single tow into a container.

A process for producing carbon fibers from a bundle, comprising a multiplicity of elongated polymeric filaments capable of being formed as a single tow when packed in a container and capable of being divided in crosswise direction into a plurality of sub-tows when taken out of said container, to be used for producing carbon fibers, wherein said acrylic polymer consists of acrylonitrile, one or more unsaturated monomers of group A and one or more unsaturated monomers of group B;

wherein said unsaturated monomers of group A are selected from the group consisting of vinyl acetate, methyl acrylate, methyl methacrylate and styrene;
and said unsaturated monomers of group B are selected from the group consisting of itaconic acid and acrylic acid;
and wherein the content AN (wt %) of said acrylonitrile in said acrylic polymer satisfies the following formula (1):
AB (wt %)≧86 (1)
and wherein the content A (wt %) of unsaturated monomer(s) selected from group A in said acrylic polymer and the content B (wt %) of said unsaturated monomer(s) selected from group B in said acrylic polymer substantially satisfy the following formulae (2) and (3):
3≦A (wt %)≦10 (2)
0.25A−0.5 B (wt %)≦0.43A−0.29 (3)
comprising the steps of:
processing said bundle by dividing it into a plurality of sub-tows,
introducing said sub-tows into a stabilizing treatment process, stabilizing said separate tows, supplying resulting stabilized tows into a carbonizing treatment process and carbonizing said stabilized tows,
said stabilizing treatment process being carried out under the following conditions:
(a) said stabilizing treatment time is in the range of from about 45 minutes to about 180 minutes,
(b) a drawing ratio of said tows is in the range of from about 0.9 to about not larger than D as defined by
D=1+(Dmax−1)×0.6
where Dmax is the maximum drawing ratio, and
(c) a tension T of said tows satisfies 30≦T (mg/d)≦120.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application

09/883,544Filed 18 Jun 2001 · division

Priority

JP 8-28906214 Oct 1996

Published

US 2001/0049016 A16 Dec 2001

Granted

21 Oct 2003

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

D01F 9/22
From macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds: from polyacrylonitriles
Y10T 428/29
Stock material or miscellaneous articles: coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic…
Y10T 428/2918
Rod, strand, filament or fiber: including free carbon or carbide or therewith [not as steel]
Y10T 428/2922
Rod, strand, filament or fiber: nonlinear [e.g., crimped, coiled, etc.]

Process for producing a precursor fiber bundle and a carbon fiber bundle

Life of this patent

Process for producing a precursor fiber bundle and a carbon fiber bundle

Life of this patent

Abstract

Claims9