Process for producing carbon fiber tows
AssigneesSumitomo Chemical Company, Limited, Japan Exlan Company Limited
InventorsAkira Sugiura, Shigeru Sawanishi, Kunio Maruyama
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Abstract
A process for producing a carbon fiber tow from an acrylic fiber tow wherein the acrylic fiber tow is treated to uniformily contain throughout the two (1) an aminosiloxane and (2) a chemical substance selected from glycerine, an alkylene glycol, and a polyalkylene glycol prior to heat-treating said acrylic fiber tow to produce the carbon fiber tow whereby problems such as fluffiness, spreading, and filament breakage are diminished.
Claims6
A process for producing carbon fiber tows from acrylic fiber tows, characterized by introducing an acrylic fiber tow, whose total number X of single filaments composing said tow is 10,000 or more, into a treating bath containing 0.5-5.0 weight % of an aminosiloxane represented by the general formula given hereunder and 0.7-7.0 weight % of a chemical substance selected from the group consisting of glycerine, an alkylene glycol whose number of carbon atoms is not less than 6 and a polyalkylene glycol whose number of carbon atoms is not less than 20, or into treating baths containing each respectively;
- regulating the tow width in the treating bath or baths to 5-10 cm per 10,000 filaments;
- treating the tow for a period of not less than 0.5 second;
- thereby preparing an acrylic fiber tow such that, when said tow is divided into Y tow portions so that each divided tow will be composed of 1000 filaments represented by Y=(X/1000), the number of divided tows whose content in the aminosiloxane is not more than 0.05 weight % based on the dry weight of the fibers, is not more than 10% relative to Y and the number of divided tows whose content in said chemical substance is not more than 0.08% based on the dry weight of the fibers, is not more than 20% relative to Y;
- and then heat-treating said acrylic fiber tow to produce a carbon fiber tow;
- said general formula of the aminosiloxane being:
- ##STR7## wherein each of R.sub.1, R.sub.2 and R.sub.3 represents hydrogen, methyl, ethyl, or phenyl;
- R.sub.4 represents --C.sub.n H.sub.2n --, wherein n is an integer from 1 to 10, or phenylene;
- each of R.sub.5 and R.sub.6 represents hydrogen or --C.sub.n H.sub.2n+1, wherein n is an integer from 1 to 5;
- each of M and N represents an integer from 1 to 100,000, wherein M+N<10;
- A represents ##STR8## wherein each of R.sub.7 and R.sub.8 represents hydrogen or alkyl whose number of carbon atoms is not more than 10, or phenyl, or ##STR9## wherein R.sub.9 represents H, C.sub.n H.sub.2n+1 in which n=1-5 or phenyl;
- and R.sub.10 represents C.sub.n H.sub.2n in which n=1-10 or phenylene.
Dependencies are inferred from the claim text.