(19)
(11) EP 0 654 291 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
20.03.1996 Bulletin 1996/12

(43) Date of publication A2:
24.05.1995 Bulletin 1995/21

(21) Application number: 94118369.1

(22) Date of filing: 22.11.1994
(51) International Patent Classification (IPC)6: B01D 9/00, G03C 1/34, G03C 7/32
(84) Designated Contracting States:
CH DE FR GB LI NL

(30) Priority: 24.11.1993 JP 319118/93

(71) Applicant: FUJI PHOTO FILM CO., LTD.
Kanagawa (JP)

(72) Inventor:
  • Ando, Kikuo, c/o Fuji Photo Film Co., Ltd.
    Odawara-shi, Kanagawa (JP)

(74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät 
Maximilianstrasse 58
80538 München
80538 München (DE)


(56) References cited: : 
   
       


    (54) Method of crystallizing organic chemicals


    (57) A method of crystallizing an organic chemical includes a step of starting crystallization that controls a degree of supersaturation of a solution of an organic chemical so as to crystallize platy crystals predominantly, and a step of crystallization which is carried out immediately after the step of starting crystallization, the step of crystallization lowering a temperature of the solution of the organic chemical while changing a composition of solvents so as to lower the degree of supersaturation of the solution of the organic chemical thereby continuing crystallization predominantly of the platy crystals. In the method, the crystals of the organic chemical are crystallized by stirring the solution of the organic chemical such that a flow of crystallized platy crystals is kept in a completely suspended state throughout the step of starting crystallization and the step of crystallization.






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