By courtesy of:
Shigeru Morita, Yasuji Iwasaki
US patent 5902908 1999 assigned to Daikin Industrials Ltd.
See also:
Process for the preparation of fluorinated unsaturated compounds and process for the product of fluoropolymers
Okamoto Hidekazu, Takaji Hirokazu, Okazoe Takashi
WO 02/20445 A1 2002 assigned to Asahi Glass Company, Ltd.