(19)
(11) EP 1 514 848 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
published in accordance with Art. 158(3) EPC

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
01.03.2006 Bulletin 2006/09

(43) Date of publication:
16.03.2005 Bulletin 2005/11

(21) Application number: 03760892.4

(22) Date of filing: 19.06.2003
(51) International Patent Classification (IPC): 
C02F 1/04(2000.01)
(86) International application number:
PCT/JP2003/007772
(87) International publication number:
WO 2004/000734 (31.12.2003 Gazette 2004/01)
(84) Designated Contracting States:
DE GB IT

(30) Priority: 19.06.2002 JP 2002178728

(71) Applicants:
  • SASAKURA ENGINEERING CO. LTD.
    Osaka 555-0012 (JP)
  • Asahi Glass Company, Limited
    Chiyoda-ku, Tokyo 100-8405 (JP)

(72) Inventors:
  • FUNAKI, Hiroshi c/o Asahi Glass Company, Limited
    Ichihara-shi, Chiba 290-8566 (JP)
  • YANASE, Koichi c/o Asahi Glass Company, Limited
    Ichihara-shi, Chiba 290-8566 (JP)
  • KAMIYA, Hiroki c/o Asahi Glass Company, Limited
    Ichihara-shi, Chiba 290-8566 (JP)
  • UEHARA, Masao c/o Asahi Glass Company, Limited
    Ichihara-shi, Chiba 290-8566 (JP)
  • NAGATOMO,Kenichiro c/o Asahi Glass Company,Limited
    Ichihara-shi, Chiba 290-8566 (JP)
  • NISHIMURA,Yasushi c/o Sasakura Engineering Co.,Ltd
    Osaka-shi, Osaka 555-0011 (JP)
  • OHNO, Shiro c/o Sasakura Engineering Co., Ltd.
    Osaka-shi, Osaka 555-0011 (JP)
  • HIRANO, Satoru c/o Sasakura Engineering Co., Ltd.
    Chuo-ku, Tokyo 104-0032 (JP)

(74) Representative: Müller-Boré & Partner Patentanwälte 
Grafinger Strasse 2
81671 München
81671 München (DE)


(56) References cited: : 
   
       


    (54) PROCESS FOR THE RECOVERY OF FLUORINE-CONTAINING EMULSIFIERS


    (57) An aqueous solution containing a fluorine-containing emulsifier in a low concentration of at least 1 ppm by mass and at most 1% by mass (e.g., coagulation waste water after an emulsion polymerization of a fluoropolymer and/or an aqueous solution obtained by washing with an aqueous solution a waste gas from a drying process and/or a heat treating process of the fluoropolymer) is subjected to vacuum concentration under a pressure of at most 100 kPa and a temperature of the aqueous solution of at most 100°C by means of a heating tube surface evaporation type concentrator equipped with a heat pump or the like, and the fluorine-containing emulsifier is recovered from a highly concentrated aqueous solution containing the fluorine-containing emulsifier in a higher concentration of at least 5% by mass. According to the present method, the fluorine-containing emulsifier can be recovered with a high yield from a low-concentration liquid such as coagulation waste water of a fluoropolymer.