초록 ▼

Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, comprising:(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;(B) fluorinated monomeric units containing sulphonyl groups ȁ

Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, comprising:(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;(B) fluorinated monomeric units containing sulphonyl groups —SO 2 F in such amount to give the above equivalent weight, deriving from F 2 C═CF—O—(CF 2 ) q —SO 2 F, q being an integer equal to 2 or 3;and having the following properties for a TFE/(B) copolymer:hydration, expressed in % of H 2 O at 100° C. absorbed by the film prepared from the ionomer and after tranformation from the —SO 2 F form into the —SO 3 H form, having the following values:

대표청구항 ▼

1. Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, comprising:(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;(B) fluorinated monomeric units containing sulphonyl groups &#x

1. Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, comprising:(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;(B) fluorinated monomeric units containing sulphonyl groups —SO 2 F in such amount to give the above equivalent weight, deriving from F 2 C═CF—O—(CF 2 ) q —SO 2 F, q being an integer equal to 2 or 3;and having the following properties for a TFE/(B) copolymer wherein q=2:hydration, expressed in % of H 2 O at 100° C. absorbed by the film prepared from the ionomer and after transformation from the —SO 2 F form into the —SO 3 H form, having the following values: 2. Ionomers according to claim 1, wherein the TFE/(B) copolymers wherein q=2 show extrudability in film, under the —SO 2 F form, with thickness of 20 μm having good mechanical properties. 3. Ionomers according to claim 1, wherein the TFE/(B) co-polymers wherein q=2 show a melt flow index comprised between 0.01 and 100 g/10′, with a load of 5 kg measured at 280° C., and after transformation from the —SO 2 F form into the —SO 3 H form. 4. Ionomers according to claim 1, wherein the TFE/(B) co-polymers wherein q=2, have the following mechanical properties of the film at 230° C. at: 5. Ionomers according to claim 1, wherein the fluorinated monomers of type (A) are selected from:vinylidene fluoride (VDF);C 2 -C 8 perfluoroolefins, preferably tetrafluoroethylene (TFE);chlorotrifluoroethylene (CTFE), optionally in the presence of ethylene,(per)fluoroalkylvinylethers (PAVE) CF 2 ═CFOR f , wherein R f is a C 1 -C 6 (per) fluoroalkyl, for example trifluoromethyl, pentafluoropropyl;perfluoro-oxyalkylvinylethers CF 2 ═CFOX, wherein X is a C 1 -C 12 perfluoro-oxyalkyl having one or more ether groups, for example perfluoro-2-propoxy-propyl. 6. Ionomers according to claim 5, wherein (A) is TFE; (B) is the monomer with q=2. 7. Ionomers according to claim 1, wherein the sulphonic fluorinated lonomers contain from 0.01 to 5% by moles of monomeric units deriving from a bis-olefin of formula: 1 R 2 C═CH—(CF 2 ) m0 —CH═CR 5 R 6   (I)wherein:m0 =2-10, preferably 4-8;R 1 , R 2 , R 5 , R 6 , equal to or different from each other, are H or C 1 -C 5 alkyl groups. 8. Ionomers according to claim 1, wherein the ionomers contain inorganic or polymer fillers in a filler amount between 0 and 20% by weight with respect to the ionomer. 9. Ionomers according to claim 1, wherein the equivalent weight is higher than 700. 10. Membranes obtainable with the ionomers according to claim 1. 11. Membranes according to claim 10, wherein the membranes are subjected to the activation treatment to transform the sulphonyl groups —SO 2 F into the sulphonic groups —SO 3 H. 12. Membranes according to claim 10, having thicknesses from 5 μM to 500 μM. 13. Membranes according to claim 10, wherein the equivalent weight is comprised between 720 and 1,200. 14. A process for operating fuel cells wherein the membranes according to claim 10 are utilized. 15. A process for the preparation of sulphonic ionomers according to claim 1 by a radical polymerization process in bulk, suspension, emulsion wherein it is used a ratio: higher than 2.20, for EW up to 800; said ratio being higher than 2.00 for EW>800. 16. A process for the preparation of sulphonic monomers according to claim 15, wherein the polymerization is carried out in aqueous emulsion or in microemulsion. 17. A process for the preparation of sulphonic ionomers according to claim 16, wherein (per)fluorinated surfactants are used selected from the salts of the perfluorooctanoic, perfluorononanoic, perfluorodecanoic acid, or mixtures thereof; (per)fluoropolyethers with an acid end group selected from COOH, —SO 3 H, salified with NH 4 + , alkaline metals, the other end group being (per)fluorinated, optionally containing one H or Cl atom. 18. A process for the preparation of sulphonic monomers according to claim 17, wherein the number average molecular weights of the perfluoropolyether surfactants range from 300 to 1,800. 19. A process for the preparation of sulphonic monomers according to claim 15, wherein the polymerization is carried out in aqueous emulsion wherein in the reaction medium as surfactants those of formula: f —X − M + are used, whereinX is equal to —COO, —SO 3 ;M is selected from H, NH 4 , alkaline metal;R f represents a (per) fluoropolyether chain, preferably having number average molecular weight comprised between about 230 and about 1,800, said (per) fluoropolyether chain comprising repeating units selected from one or more of the following:a) —(C 3 F 6 O) —;b) —(CF 2 CF 2 O) —;c) —(CFL 0 O) —, wherein L o —F, —CF 3 ;d) —CF 2 (CF 2 ) z′ CF 2 O—, wherein z′ is an integer 1 or 2;e) —CH 2 CF 2 CF 2 O—;R f is monofunctional, and has a (per)fluorooxyalkyl end group T, optionally in the perfluoroalkyl end groups one fluorine atom is substituted by one chlorine or hydrogen atom.