PROCESS FOR PRODUCING FLUOROCARBON POLYMERS THAT CONTAIN CARBOXYL GROUPS, SOME STARTING MATERIALS THEREFOR AND THE FLUOROSULPHATE COMPOUNDS OCCURRING AS INTERMEDIATES IN THE PROCESS

摘要

(1).COOH gp.-contg. uncrosslinked fluorocarbon polymers are prepd. by (a) first reacting partly new uncrosslinked fluorocarbon polymers in which linear macromols. bear side-chains having the end-gp. -CHFX (where X is F or CF3) with peroxydisulphuryl difluoride FSO2O-OSO2F to form the corresp. fluorosulphato derivs. (I), contg. side-chain end-gps. -CFX-OSO2F. (b) If (i) X is F, (I) are reacted with an alcohol havino formula ROH (where R is 1-6C alkyl, esp. Me or Et) to form esters having side-chain end qps. -COOR, which are saponified to the free -COOH gps., as such or in salt form. Alternatively, (I) are hydrolysed directly with water, in the presence of a solvent, and/or base, to prods. contg. -COOH in free or salt form as the side-chain end gp. If (ii) X is CF3, (I) are decomposed to ketones contg. side-chain end gps. -CO-CF3 in the presence of alkali fluoride- and/or aprotic N base catalysts. The ketones are then hydrolysed to prods. contg. -COOH, in free- or salt form, as side-chain end gps. (2).New uncrosslinked fluorocarbon copolymers, used as raw materials, contain repeat units having formula -CF2-CF(-(-OCF2CFY-)u-Ov-(CF2)w-CHFX)- (A) (where u is 0, 1 or 2; v is 0 or 1; w is 1-7; X and Y each is F or CF3) and repeat units having formula -CF2-CFZ- (B) (where Z is Cl, F, Rf or -ORf; Rf is CF3 or opt. O atom-interrupted 2-8C perfluoroalkyl) provided (A):(B) molar ratio is 1:(2-20) esp. 1:(2-8). Intermediates (I) are also new. The COOH gp.-contg. uncrosslinked fluorocarbon polymers are used as cation exchanqer membranes in electrolysis cells, esp. in alkali chloride electrolysis.