ACRYLONITRILE-BASED COPOLYMER, ACRYLONITRILE-BASED CARBON FIBER PRECURSOR FIBER AND METHOD FOR PRODUCING CARBON FIBER

• Main Authors: MATSUMOTO NAOHIRO, SADO YUKI, WATANABE FUMIYOSHI
• Format: Patent
• Language: English; Japanese
• Published: 22.10.2015
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; NATURAL OR ARTIFICIAL THREADS OR FIBRES; ORGANIC MACROMOLECULAR COMPOUNDS; SPINNING; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To provide a method of improving a carbonization yield without damaging productivity and process properties in a carbon fiber production process.SOLUTION: Provided is an acrylonitrile-based copolymer in which the copolymerization ratio of acrylonitrile is 95 to 99.5 mol% or higher, and the copolymerization ratio of styrene is 0.5 to 1.5 mol%. Also provided is a method for producing a polyacrylonitrile-based carbon fiber precursor fiber comprising: a spinning step where the copolymer is spun by a wet spinning method or a dry-wet typ spinning method; a dry heat treatment step where the fiber obtained in the spinning step is subjected to dry heat treatment; and a drawing step where the fiber obtained by the dry heat treatment step is drawn. Also provided is a method for producing carbon fiber comprising: a flame-resistance imparting step where the polyacrylonitrile-based carbon fiber precursor fiber is imparted with flame resistance in the air at 200 to 300°C; a pre-carbonization step where teh fiber obtained in the flame-resistance imparting step is carbonized in an inert atmosphere heated at 900 to 3,000°C. 【課題】炭素繊維製造工程において生産性及びプロセス性を損なうことなく炭化収率を向上する方法の提供。【解決手段】アクリロニトリルの共重合比が９５〜９９．５ｍｏｌ％以上、スチレンの共重合比が０．５〜１．５ｍｏｌ％であるアクリロニトリル系共重合体。前記共重合体を湿式紡糸法又は乾湿式紡糸法により紡糸する紡糸工程と、該紡糸工程で得られた繊維を乾燥熱処理する乾燥熱処理工程と、該乾燥熱処理工程で得られた繊維を延伸する延伸工程とを備えたポリアクリロニトリル系炭素繊維前駆体繊維の製造方法。前記ポリアクリロニトリル系炭素繊維前駆体繊維を２００〜３００℃の空気中において耐炎化する耐炎化工程と、該耐炎化工程で得られた繊維を、３００〜９００℃の不活性雰囲気中において予備炭化する予備炭化工程と、該予備炭化工程で得られた繊維を、９００〜３，０００℃の不活性雰囲気中において炭化する炭化工程とを備えた炭素繊維の製造方法。【選択図】なし