Mitsubishi Rayon Company, Limited

Mitsubishi Chemical Corporation

Katsuhiko Ikeda

Yukio Kasabo

Atsushi Kawamura

Hiromasa Inada

Yoshihiko Mishina

Yasuyuki Fujii

Ryo Ochi

Toshihiro Makishima

Masashi Okamoto

Masakazu Hoshino

Aritaka Shimotashiro

Takayoshi Yamamoto

Nobuyuki Shimozawa

Atsushi Nakajima

Norifumi Hirota

Kouki Wakabayashi

Akito Hatayama

Kenji Hirano

Kenji Kaneta

Naomasa Matsuyama

Akihiro Itou

Takahiko Kunisawa

Nobuyuki Fukuen

Yuutarou Nakamura

Hiroko Matsumura

Tadashi Ootani

A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Carbon fiber precursor acrylic fiber, carbon fiber, and method for producing same

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. A carbon fiber precursor fiber bundle that has a degree of intermingle of 1 mor 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.

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

The invention provides a packaged tow being characterized in that a carbon fiber precursor tow having a flattened shape in cross section and having a first surface and a second surface opposite to the first surface is layered and packaged in a packaging container in untwisted state. A front end and a back end of the carbon fiber precursor tow thus packaged are placed on a top of the fully-packaged carbon fiber precursor tow. When the front end and a back end of the tow are respectively applied with top/bottom surface identification means to identify top and bottom surfaces thereof, top and bottom surfaces on front ends and back ends of tows packaged in a plurality of packaging containers can be correctly identified and joined. As a result, thread breakage due to heat accumulation in twisted parts in a flame proofing process can be prevented from happening.

Packaged carbon fiber precursor tow, and method and device for manufacturing same

Disclosed are a wet spinning apparatus and a wet spinning method, which enable to manufacture fibers with excellent quality by controlling the flow of a coagulation liquid in a spinning bath and which enable to cope with high speed spinning (or high speed drawing). A wet spinning apparatus comprises a spinning bath at one end in which there are provided a nozzle for discharging a spinning raw liquid and coagulation liquid discharge ports and for discharging a coagulation liquid, at the other end in which there are provided a drawing roll for drawing coagulated filaments and a coagulation liquid recovery portion into which the coagulation liquid flows out. The spinning bath has a coagulation bath portion having a cross sectional area gradually reduced from one end to the other end, for coagulating the spinning raw liquid, and a filament running portion having a cross sectional area gradually enlarged from one end to the other end, for allowing the coagulated filaments to run therein.

Method for wet spinning

A production method for a carbon fiber precursor fiber bundle and a production apparatus of the carbon fiber precursor fiber bundle. A carbon fiber precursor fiber bundle that has a degree of intermingle of 1 m&#x2212;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.

Process of making a carbon fiber precursor fiber bundle

Disclosed are a wet spinning apparatus and a wet spinning method, which enable to manufacture fibers with excellent quality by controlling the flow of a coagulation liquid in a spinning bath and which enable to cope with high speed spinning (or high speed drawing). A wet spinning apparatus () comprises a spinning bath (), at one end in which there are provided a nozzle () for discharging a spinning raw liquid and coagulation liquid discharge ports () and () for discharging a coagulation liquid (C), at the other end in which there are provided a drawing roll () for drawing coagulated filaments () and a coagulation liquid recovery portion () into which the coagulation liquid (C) flows out. The spinning bath () has a coagulation bath portion () having a cross sectional area gradually reduced from one end to the other end, for coagulating the spinning raw liquid, and a filament running portion () having a cross sectional area gradually enlarged from one end to the other end, for allowing the coagulated filaments () to run therein.

Wet spinning apparatus

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 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.

There is disclosed an acrylic fiber (a) consisting of an acrylonitrile polymer comprising an acrylonitrile unit in at least 80 wt % and less than 95 wt %, (b) having a monofilament dry strength of 2.5 to 4.0 cN/dtex, (c) having a monofilament dry elongation of 35 to 50%, and (d) forming a crack with a length of 20 &mgr;m or more in its tension rupture lateral surface along the filament axis direction when rupturing the monofilament in a tension test. The fiber has even orientation in its surface and inside; is significantly improved in dry strength, dry elongation and dyeability; and exhibits wool-like hand feeling. It is, therefore, quite suitable as a synthetic fiber for various applications such as a garment material, e.g., a sweater and a home furnishing material such as a pile.

Acrylic fiber and a manufacturing process therefor

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 &mgr;m 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.

Acrylonitrile-based fiber bundle for carbon fiber precursor and method for preparation thereof

Acrylonitrile-based synthetic fiber and method for production thereof

The carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the ratio of the length and width of the fiber cross section of a monofilament (length/width) is 1.05 to 1.6, and the amount of Si measured by ICP (Inductively Coupled Plasma) atomic emission spectrometry is in the range of 500 to 4,000 ppm. This type of carbon fiber precursor fiber bundle has a high compactness, and the carbonizing processing ability is good. Furthermore, for the carbon fiber bundle which is to obtained hereafter, the resin impregnating ability and tow spreading ability are good, the strength increases, and it has bulkiness. Furthermore, the carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the liquid content ratio HW is 40 wt. % or more and less than 60 wt. %. The carbon fiber bundle obtained from this type of carbon fiber precursor fiber bundle improves the bulkiness and is superior in resin impregnating ability, tow spreading ability, and covering ability when made into cloth.

Carbon fiber bundle

Carbon fiber precursor fiber bundle and manufacturing method of the same

An acrylic fiber tow having a total size of at least 22,000 dtex and a weight variation ratio in the longitudinal direction of not greater than 3.5%, which is useful as a precursor for carbon fiber production.

Growing community of inventors

Otake, Japan

Katsuhiko Ikeda