(19)
(11) EP 0 301 915 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.11.1989 Bulletin 1989/48

(43) Date of publication A2:
01.02.1989 Bulletin 1989/05

(21) Application number: 88307084.9

(22) Date of filing: 01.08.1988
(51) International Patent Classification (IPC)4: D01F 9/22
(84) Designated Contracting States:
DE FR GB

(30) Priority: 31.07.1987 JP 190301/87

(71) Applicant: TORAY INDUSTRIES, INC.
Tokyo (JP)

(72) Inventors:
  • Akimoto, Tatsuo
    Otsu-shi Shiga-ken, 520-21 (JP)
  • Ogasawara, Masafumi
    Otsu-shi Shiga-ken, 520 (JP)
  • Sumida, Atsushi
    Iyo-gun Ehime-ken, 791-21 (JP)

(74) Representative: Coleiro, Raymond et al
MEWBURN ELLIS York House 23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB)


(56) References cited: : 
   
       


    (54) Method for producing oxidized filaments


    (57) In a method for producing oxidized filaments (102) by treating precursor filaments (101) in a bed (5a) fluidized by an oxidizing gas and heat treating the precursor filaments (101) in the fluidized bed (5a), the fluidized bed (5a) is formed with heat-medium particles (5), not less than 80% by weight of which are of solid particles each having a particle diameter of not greater than 10 mesh, and the oxidation is carried out under optimum conditions within an optimum range of the treatment temperatures, an optimum range of depths H of the fluidized bed (5a) and an optimum gas speed of the oxidizing gas. By the method, the period of time required for the oxidation can be greatly shortened and oxidized filaments (102) having excellent characteristics can be obtained Furthermore, where the oxidized filaments thus obtained are carbonized, carbon fibers having excellent mechanical properties can be produced.






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