Acrylonitrile-based fiber bundle for carbon fiber precursor and method for preparation thereof
AssigneeMitsubishi Rayon Co., Ltd.
InventorsYukio Kasabo, Katsuhiko Ikeda
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Abstract
There is disclosed an acrylonitrile fiber bundle for a carbon fiber precursor with a total denier of 30,000 or more consisting of an acrylonitrile polymer comprising 95 wt % or more of an acrylonitrile unit, wherein the surface of filaments composing of the fiber bundle has 2 to 15 corrugation with a height of 0.5 to 1.0 μm which are substantially continuous in a longitudinal direction and an iodine adsorption per a fiber weight of the fiber bundle is 0.5 to 1.5 wt %. The fiber bundle shows a large total size, a small drying load owing to its good denseness and a good convergence so that it is suitably used as precursors for carbon fibers.
Claims14
An acrylonitrile fiber bundle for a carbon fiber precursor with a total denier of 30,000 or more consisting of an acrylonitrile polymer comprising 95 wt % or more of an acrylonitrile unit, wherein the surface of filaments composing of the fiber bundle has 2 to 15 corrugation with a height of 0.5 to 1.0 μm which are substantially continuous in a longitudinal direction and the amount of iodine adsorbable to fiber weight of the fiber bundle is 0.5 to 1.5 wt %.
A process for producing an acrylonitrile fiber bundle for a carbon fiberprecursor comprising the steps of:
- discharging a spinning feed solution of an acrylonitrile polymer having 95 wt % or more of an acrylonitrile unit in a first organic solvent into a first coagulation bath at 30 to 50° C. consisting of an aqueous organic-solvent solution comprising 50 to 70 wt % of the second organic solvent capable of solving the acrylonitrile polymer, to prepare a coagulated fiber;
- drawing the coagulated fiber from the first coagulation bath at a drawing rate of 0.8 folds or less of the linear discharge velocity of the spinning feed solution;
- and
- then stretching the coagulated fiber to 1.1 to 3.0 folds in a second coagulation bath at 30 to 50° C. consisting of an aqueous organic-solvent solution comprising 50 to 70 wt % of the third organic solvent capable of solving the acrylonitrile polymer.
A process for producing an acrylonitrile fiber bundle for a carbon fiber precursor comprising the steps of:
- discharging a spinning feed solution of an acrylonitrile polymer having 95 wt % or more of an acrylonitrile unit in a first organic solvent into a first coagulation bath at 30 to 50° C. consisting of an aqueous organic-solvent solution comprising 50 to 70 wt % of the second organic solvent capable of solving the acrylonitrile polymer, to prepare a coagulated fiber;
- drawing the coagulated fiber from the first coagulation bath at a drawing rate of 0.8 folds or less of the linear discharge velocity of the spinning feed solution;
- stretching the coagulated fiber to 1.1 to 3.0 folds in length in a second coagulation bath at 30 to 50° C. consisting of an aqueous organic-solvent solution comprising 50 to 70 wt % of the third organic solvent capable of solving the acrylonitrile polymer;
- and
- then further wet-heat stretching the resulting fiber to 4 folds or more.
Dependencies are inferred from the claim text.