Functionalized fluorinated polymer and process for its preparation

Abstract

The present invention relates to a copolymer comprising monomeric units derived from a fluorinated monomer and monomeric units derived from a cyclic disulfide compound. The present invention also relates to a process for producing said copolymer and its use in various applications.

Description

Title of the invention: Functionalized fluorinated polymer and process for preparing the same Technical field

[0001] The present invention relates to a functionalized fluoropolymer. In particular, the present invention relates to a copolymer comprising monomeric units derived from a fluoromonomer and monomeric units derived from a cyclic disulfide compound. Technological background of the invention

[0002] Semi-fluorinated polymers are widely used due to their unique properties such as thermal stability, chemical inertness (to solvents, oils, water, acids and bases) and mechanical properties. Therefore, they can be applied in many fields such as aeronautics, microelectronic tubes, engineering, chemical industry, automobile industry and wiring insulation.

[0003] Polyvinylidene fluoride is of particular importance because it can be used in a wide range of applications from piezoelectric materials to water treatment and energy storage. It can be prepared as an emulsion or suspension. The type of process can affect the molecular structure and reactivity of vinylidene fluoride with other monomers. This difference in microstructure, as well as the functionality of the polymer chain, can have a profound impact on certain high-tech applications such as coatings and energy storage materials.

[0004] Emulsion polymerization is characterized by its high productivity and yields branched products. However, the incorporation of monomers with functional groups can be complex. The introduction of non-fluorinated monomer can reduce the reactivity of the system, resulting in lower productivity and reactor fouling problems. Functionalization of poly(vinylidene fluoride) can also be achieved by plasma treatment and electron beam irradiation approaches. However, some technical limitations such as industrialization and repeatability can be difficult.

[0005] There is therefore a need for a new method for preparing new fluorinated polymers that is simple, efficient and has a limited environmental impact. Summary of the invention

[0006] According to a first aspect, the present invention provides a copolymer comprising monomeric units derived from a fluorinated vinyl monomer Ml and monomeric units derived from a 5, 6 or 7-membered cyclic monomer M2 of formula (I) [CRaRb]n ! ) \ I S—s 7 (I)

[0007] in which n is an integer from 3 to 5; Ra and Rb are, independently of each other and independently for each unit n, selected from the group consisting of H, F, C1-C2o alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C1-C20 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-C20 cycloalkyl substituted or not by one or more functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type;C6-C2o aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; or the unit [CRaRb] forms a carbonyl group C=O or thiocarbonyl group C=S; ;

[0008] characterized in that at least one of the substituents Ra or Rb of at least one unit n comprises a functional group -CO2H.

[0009] The present invention allows the preparation of a fluoropolymer functionalized with a thioether comonomer by an emulsion process. Comonomers comprising a disulfide bond are known to inhibit radical polymerizations. By choosing a cyclic disulfide monomer and an appropriate amount thereof in the process, it is possible to maintain radical polymerization and to form functionalized fluoropolymers. In addition, the presence of a CO2H functional group on the comonomer M2 makes it possible to improve the adhesion properties of an electrode incorporating said copolymer according to the invention. In the monomer M2 of formula (I), Ra and Rb are the substituents of the carbon atom C of the unit [CRaRb ]•

[0010] According to a preferred embodiment, in said copolymer, at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H with m is an integer between 1 and 8; R5, R6 and R7 are independently of each other H, F, C1-C5 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide type, cyano, ester, thioester, sulfonic acid, phosphoric acid, C1-C5 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide type, cyano, ester, thioester, sulfonic acid, phosphoric acid, C3-C6 cycloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid, C6-C12 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; R8 is selected from the group consisting of H, C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type.

[0011] According to a preferred embodiment, in said copolymer, said monomer M2 is of formula (I) ai j Mi it

[0012] wherein R5 and R6 are independently of each other H, C1-C5 alkyl, C3-C6 cycloalkyl, C6-C12 aryl or C1-C5 fluoroalkyl; R8 is selected from the group consisting of H, C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6.

[0013] According to a preferred embodiment, said monomer M2 is lipoic acid.

[0014] According to a preferred embodiment, said monomer M1 is selected from: group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2 =CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene.

[0015] According to a preferred embodiment, said monomer M1 is vinylidene fluoride.

[0016] According to a preferred embodiment, said copolymer comprises units of formula (II) -CHzCFz-S-CQROCR^LS-QR'XR^QR3)^^ with n, R“ and Rb as defined in the present application; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3.

[0017] According to a preferred embodiment, said copolymer comprises monomeric units derived from a monomer M1 being vinylidene fluoride and said copolymer also comprises monomeric units derived from a monomer M3 selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2 =CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene,hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate,hydroxyethylhexyl methacrylate, acryloyloxy propylsuccinate and combinations thereof.

[0018] According to another aspect, the present invention provides a process for producing a copolymer according to the present invention characterized in that it comprises a step a) of polymerization of a fluorinated monomer M1 in the presence of a 5, 6 or 7-membered cyclic monomer M2 of formula (I) [CRaRfa]n s—S (I)

[0019] as defined in the present application and an initiator, characterized in that said monomer M2 is added in step a) in the form of a solution, preferably aqueous, the concentration of which is greater than or equal to 5 g / l.

[0020] According to a preferred embodiment, step a) is carried out at a temperature above 40°C and a pressure of 10 to 120 bara.

[0021] According to a preferred embodiment, said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2 =CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene. ,

[0022] According to a preferred embodiment, said monomer M1 is vinylidene fluoride.

[0023] According to a preferred embodiment, step a) is carried out in the presence of a monomer M3 selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene,2-trifluoromethyl-3,3,3-trifluoro-l-propene, acrylic acid, me- acid, thacrylic, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate, hydroxyethylhexyl methacrylate, acryloyloxy propyl succinate and combinations thereof.

[0024] According to another aspect, the present invention provides a binder for an electrode or coating for a separator comprising said copolymer according to the present invention.

[0025] According to another aspect, the present invention provides an electrode or separator comprising said copolymer according to the present invention.

[0026] According to another aspect, the present invention provides a battery, preferably lithium-ion, comprising said electrode or said separator according to the present invention.

[0027] According to another aspect, the present invention provides the use of said copolymer according to the present invention for the preparation of a conductive polymer, a solid electrolyte for fuel cells, a hydrophilic coating, a hydrophobic coating or a UV absorbing coating; or as an adhesive for a multilayer structure extruded in the form of a film, a sheet or a tube; or said copolymer is used as a coating on a metal. Detailed description of the invention Monomer Ml

[0028] The term “fluorinated vinyl monomer” means a monomer comprising a C=C double bond and comprising at least one fluorine atom.

[0029] According to one embodiment, said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene.

[0030] Preferably, said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH20H, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4.

[0031] More preferably, said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene. In particular, said monomer M1 is vinylidene fluoride. Monomer M2

[0032] Said monomer M2 is a cyclic compound comprising a disulfide bond.

[0033] Preferably, said monomer M2 is a 5-, 6- or 7-membered cyclic compound of formula (I) [CRaRb]n (I)

[0034] in which n is an integer from 3 to 5; Ra and Rb are, independently of each other and independently for each unit n, selected from the group consisting of H, F, CrC2o alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; CrC2o fluoroalkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; C3-C20 cycloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C6-C20 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain;or the unit [CRaRb] forms one; carbonyl group C=O or thiocarbonyl group C=S.

[0035] The term carboxylic acid refers to a CO2H functional group or a salt thereof. The term amine refers to a -NR'R” functional group in which R' and R” are independently H or C1-C5 alkyl. The term hydroxyl refers to an -OH functional group. The term ketone refers to a -C(O)-R' functional group with R' being C1-C5 alkyl. The term aldehyde refers to a -C(O)H functional group. The term amide refers to a -C(O)-NR'R” functional group in which R' and R” are independently H or C1-C5 alkyl. The term cyano refers to a -CN functional group. The term ester refers to a -C(O)-OR' or -OC(O)-R' functional group with R' being C1-C5 alkyl. The term thioester refers to a functional group -C(S)-OR' or -OC(S)-R' with R' being C1-C5 alkyl. The term sulfonic acid refers to a functional group -SO3H or a salt thereof.The term phosphoric acid refers to a functional group -P(O)(OH)2 or a salt thereof. When these substituents are arranged on a cycloalkyl or aryl, they are preferably located in the meta or para position. The expression polymeric hydrocarbon chain refers to a polymer comprising monomeric units derived from a vinyl group optionally substituted by one or more functional groups of the carboxylic acid, halogen, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and onto which one of the substituents Ra or Rb of the monomer M2 of formula or one of the substituents R5, R6, R7 or R8 is grafted.For example, the polymeric hydrocarbon chain may be polyethylene, polypropylene, poly(acrylic acid), poly(methyl methacrylate), poly(methyl acrylic acid), poly(vinylidene fluoride), poly(tetrafluoroethylene), poly(trifluoroethylene), poly(chlorotrifluoroethylene), polystyrene, polybutadiene. Preferably, the polymeric hydrocarbon chain is preferably a polymer comprising monomeric units M1, M3 or a mixture of both.

[0036] Preferably, at least one of the substituents Ra or Rb of at least one unit n comprises a functional group -CO2H. As mentioned above, the presence of a functional group CO2H on the comonomer M2 makes it possible to improve the adhesion properties of an electrode incorporating said copolymer according to the invention.

[0037] More preferably, said monomer M2 is a 5-, 6- or 7-membered cyclic compound of formula (I) [CRaRfa]n s—S (I)

[0038] in which n is an integer from 3 to 5; Ra and Rb are, independently of each other and independently for each unit n, selected from the group consisting of H, F, C3-C2o alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-C20 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-Ci0 cycloalkyl substituted or not by one or more functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type;C6-Ci2 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; and at least one of the substituents Ra or Rb of at least one n unit comprises a functional group -co2h.;

[0039] In particular, said monomer M2 is a 5 or 6-membered cyclic compound of formula (I) [CRaRb]n k) s—S (I)

[0040] in which n is 3 or 4; Ra and Rb are, independently of each other and independently for each n unit, selected from the group consisting of H, F, C3-C8 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; and at least one of the substituents Ra or Rb of at least one n unit comprises a -CO2H functional group.

[0041] According to a preferred embodiment, in said copolymer, at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H with m is an integer between 1 and 8; R5, R6 and R7 are independently of each other H, F, C1-C5 alkyl substituted or not by one or more groups functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid, C1-C5 fluoroalkyl type substituted or not by one or more functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-C6 cycloalkyl substituted or not by one or more functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C6-C12 aryl substituted or not by one or more functional groups of the carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain;R8 is selected from the group consisting of H, C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type. Preferably, at least one of the substituents Ra or Rb in at least one of the n units is of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H with m is an integer between 3 and 6; R5, R6 and R7 are independently of each other H, F, CrC3 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type, CrC3 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type;C4-C6 cycloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C6-Ci0 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; R8 is selected from the group consisting of H, Ci-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type. In particular, at least one of the substituents Ra or Rb in at least one of the n units is of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H with m being an integer between 3 and 6; R5, R6 and R7 are independently of each other H or F;R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type. More particularly, at least one of the substituents Ra or Rb in at least one of the n units is of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H with m is an integer between 3 and 6; R5, R6 and R7 are H; R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type. ;

[0042] According to a preferred embodiment, in said copolymer, said monomer M2 is a five-membered cyclic compound (n = 3) of formula (I). Advantageously, said monomer M2 is of formula (I) below R < x d)

[0043] in which R5 and R6 are independently of each other H, C1-C5 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C1-C5 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-C6 cycloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C6-Ci2 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain;R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6, preferably m is an integer from 3 to 6.;

[0044] Preferably, said monomer M2 is of formula (I) below: j H!

[0045] in which R5 and R6 are independently of each other H, CrC3 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type, Ci-C3 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; R8 is selected from the group consisting of H and Ci-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6, preferably m is an integer from 3 to 6.

[0046] More preferably, said monomer M2 is of formula (I) below: y~ co.>H r Wn h5 L_ _S Hî m

[0047] in which R5 and R6 are independently of each other H, C1-C3 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6, preferably m is an integer from 3 to 6.

[0048] In particular, said monomer M2 is of formula (I) below: œ

[0049] in which R5 and R6 are H; R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6, preferably m is an integer from 3 to 6.

[0050] More particularly, said monomer M2 is the lipoic acid of formula (I) below

[0051] in which R5, R6 and R8 are H; m = 4. Copolymer

[0052] As mentioned above, the present invention provides a copolymer comprising monomeric units derived from a fluorinated vinyl monomer M1 and monomeric units derived from a monomer M2 comprising a disulfide bond according to any one of the above embodiments.

[0053] In a preferred embodiment, said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene.

[0054] According to one embodiment, said copolymer may comprise units of formula (II) -CHzCFz-S-CQROCR^LS-QR'XR^QRsXR4)^ with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the n units is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0055] According to one embodiment, said copolymer may comprise units of formula (II) -CH2CHF-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0056] According to one embodiment, said copolymer may comprise units of formula (II) -CHFCF2-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0057] According to one embodiment, said copolymer may comprise units of formula (II) -CF2CF2-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0058] According to one embodiment, said copolymer may comprise units of formula (II) -CClFCF2-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above. above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the n units is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0059] According to one embodiment, said copolymer may comprise units of formula (II) -CHFCHF-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0060] According to one embodiment, said copolymer may comprise units of formula (II) -CF2C(CF3)FS-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]m -C(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.

[0061] In particular, said monomer M1 is vinylidene fluoride. Thus, said copolymer may comprise units of formula (II) -CH2CF2-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H when R3 and R4 are F or R' and R2 are F when R3 and R4 are H. Preferably at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above.In particular, said copolymer may comprise units of formula (II) -CH2CF2-S-CH2 CH2CH(Ra)-SC(R1)(R2)C(R3)(R4)- with Ra of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H as defined in the present application according to any one of the embodiments above; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and CF3; preferably R' and R2 are H. when R3 and R4 are F or R' and R2 are F when R3 and R4 are H.

[0062] According to a preferred embodiment, said copolymer also comprises monomeric units derived from a monomer M3 different from the monomer M1 and selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene,bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate, hydroxyethylhexyl methacrylate,acryloyloxy propyl succinate and combinations thereof. ,

[0063] According to a preferred embodiment, said copolymer comprises monomeric units derived from a monomer M1 being vinylidene fluoride and also comprises monomeric units derived from a monomer M3 selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate,hydroxyethylhexyl methacrylate, acryloyloxy propylsuccinate and combinations thereof.

[0064] According to a particular embodiment, said copolymer comprises monomeric units derived from a monomer M1 being vinylidene fluoride and also comprises monomeric units derived from a monomer M3 selected from the group consisting of trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate,propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, acrylate hydroxyethylhexyl, hydroxyethylhexyl methacrylate, acryloyloxy propylsuccinate and combinations thereof.

[0065] In said copolymer, the content of monomeric units derived from the monomer M2 is from 0.01% to 5% by mole, preferably from 0.01% to 1% by mole, in particular 0.01% to 0.5% by mole. Preparation process

[0066] According to another aspect, the present invention provides a process for producing a copolymer according to the present invention characterized in that it comprises a step a) of polymerization of a fluorinated monomer M1 in the presence of a 5, 6 or 7-membered cyclic monomer M2 of formula (I) [CRaRb]n ! \ \ JS— s7 (I)

[0067] as defined in the present application and an initiator. Said monomer M1 and said monomer M2 are as defined above in the present application according to any one of the embodiments and according to any one of the possible combinations. According to a particular embodiment, said monomer M1 is vinylidene fluoride. According to a particular embodiment, said monomer M2 is lipoic acid.

[0068] Advantageously, said monomer M2 is added in step a) in the form of a solution whose concentration is greater than or equal to 5 g / l. Preferably, said monomer M2 is added in step a) in the form of a solution whose concentration is greater than or equal to 5.5 g / l, more preferably greater than or equal to 6 g / l. In particular, said monomer M2 is added in step a) in the form of a solution whose concentration is less than 12 g / l, preferably less than 11 g / l, in particular less than 10 g / l. Thus, according to a preferred embodiment, said monomer M2 is added in step a) in the form of a solution whose concentration is between 5 g / l and 12 g / l, advantageously between 5.5 g / l and 11 g / l, preferably between 6 g / l and 10 g / l. Preferably, said solution comprises water in order to solubilize said monomer M2. In particular, said solution is an aqueous solution.

[0069] Step a) of the present process can be carried out in emulsion or in suspension, preferably in emulsion. In particular, step a) is carried out in emulsion in aqueous phase.

[0070] According to a preferred embodiment, said monomer M2 can be added continuously or discontinuously. The term continuous encompasses the addition of the monomer M2 by multiple additions throughout the production process. The term discontinuous encompasses the addition of the monomer M2 once at the beginning of the process or during the process in a single addition. Preferably, said monomer M2 is added continuously. The addition of said monomer M2 can be prior to, simultaneous with or subsequent to that of the initiator.

[0071] Preferably, said monomer M1 is added continuously or discontinuously. However, it is preferable to add at least a portion of said monomer M1 in the initial charge of the reactor, i.e. before the initiation of the polymerization reaction.

[0072] According to a preferred embodiment, the addition of said monomer M2 is subsequent to that of the initiator and that of the monomer M1.

[0073] Preferably, step a) is carried out at a temperature above 40°C, preferably at a temperature of 40°C to 120°C, in particular of 40°C to 90°C.

[0074] Step a) of the present process is preferably carried out at a pressure of 10 to 120 bara, advantageously at a pressure of 15 bara to 110 bara, preferably at a pressure of 20 bara to 100 bara.

[0075] The initiator may be one or a combination of several of the initiators known in the art to be useful in the emulsion polymerization of halogenated monomers. Suitable non-limiting classes of initiators include persulfate salts, peroxides, and redox systems. Examples of persulfate salts are sodium persulfate, potassium persulfate, or ammonium persulfate. The amount of persulfate salt added to the reaction mixture based on the total weight of monomer added to the reaction mixture is typically about 0.005 to about 1.0 wt. %. Organic peroxides that are useful include dialkyl peroxides, alkyl hydroperoxides, peroxyesters, and peroxydicarbonates. A suitable example of a dialkyl peroxide is di-tert-butyl peroxide. Examples of suitable peroxy esters include tert-amyl peroxypivalate, tert-butyl peroxypivalate and succinic acid peroxide.Examples of suitable peroxydicarbonate initiators include di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate, which are typically added to the reaction mixture in an amount based on the total weight of monomer added to the reaction mixture of about 0.5 to about 2.5 wt. %.

[0076] The initiator may comprise a redox system. By "redox system" is meant a system comprising an oxidizing agent, a reducing agent, and optionally a promoter acting as an electron transfer medium. The promoter is a component which, in different oxidation states, is capable of reacting with both the oxidizing agent and the reducing agent, thereby accelerating the overall reaction. Oxidizing agents include, for example, persulfate salts; peroxides, such as hydrogen peroxide; hydroperoxides, such as tert-butyl hydroperoxide and cumene hydroperoxide; and oxidizing metal salts such as, for example, ferric sulfate and potassium permanganate. Examples of reducing agents include sodium formaldehyde sulfoxylate; sodium or potassium sulfite, bisulfite, or meta-bisulfite; ascorbic acid; oxalic acid; and meta-bisulfite salts. reduced metals. Typical promoters include transition metal salts such as ferrous sulfate. In redox systems, the oxidizing agent and reducing agent are typically used in an amount of about 0.01 to about 0.5 weight percent based on the total weight of monomer added to the reaction mixture. The promoter, if used, is typically employed in an amount of about 0.005 to about 0.025 weight percent based on the total weight of monomer added to the reaction mixture.

[0077] According to a preferred embodiment, step a) is carried out in the presence of a monomer M3 different from said monomer M1 and selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene,chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, methacrylate hexyl, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, and combinations thereof.

[0078] Said monomer M3 can be added to the initial charge of the reactor or during the polymerization reaction of said monomer M1 with said monomer M2. The addition of said monomer M3 can be carried out continuously or discontinuously.

[0079] A paraffin antifoulant is optionally used in the polymerization. Any long-chain saturated hydrocarbon wax or oil may be used. The oil or wax is added to the reactor prior to fluoropolymer formation, in an amount sufficient to minimize polymer adhesion to the reactor components. This The amount is generally proportional to the interior surface area of ​​the reactor and can vary from about 1 to about 40 mg / cm2 of interior surface area of ​​the reactor. If a paraffin wax or hydrocarbon oil is used as an antifoulant, the amount used is generally about 5 mg / cm2 of interior surface area of ​​the reactor.

[0080] The polymerization reaction mixture may optionally contain a buffering agent to maintain a controlled pH during the polymerization reaction. The pH is generally controlled in the range of 3 to 8. The buffering agent may be added at the beginning, at different points or throughout the polymerization. Suitable exemplary buffering agents are phosphate buffers and acetate buffers, which are well known to those skilled in the art.

[0081] Molecular weight regulators, also known as chain transfer agents, may optionally be used to adjust the molecular weight profile of the product. They may be added in a single portion at the beginning of the reaction, gradually, or continuously throughout the reaction. The amount of molecular weight regulator added to the polymerization reaction is generally from about 0.05 to about 5% by weight, more generally from about 0.1 to about 2% by weight based on the total weight of monomer added to the reaction mixture. Oxygenated compounds such as alcohols, carbonates, ketones, esters, and ethers may serve as molecular weight regulators. Examples of suitable oxygenated compounds include isopropyl alcohol, acetone, ethyl acetate, and diethyl carbonate.Other classes of molecular weight regulators include halogenated compounds such as chlorocarbons, hydrochlorocarbons, hydrofluorocarbons, chlorofluorocarbons, and hydrochlorofluorocarbons. Particular examples of halogenated molecular weight regulators include 1-fluoroethane, trichlorofluoromethane, and 1,1-dichloro-2,2,2-trifluoroethane. Certain hydrocarbons can be used as molecular weight regulators, such as hydrocarbons that contain two to five carbon atoms, with ethane and propane as particular examples.

[0082] Step a) of the present method may optionally be carried out in the presence of a surfactant SI. For example, said surfactant SI comprises a polyethylene glycol segment and a polypropylene glycol segment. Preferably, said surfactant SI has an HLB value of 1 to 20, in particular an HLB value of 1 to 5 or 10 to 15. In particular, said surfactant SI comprising a polyethylene glycol segment and a polypropylene glycol segment, has an HLB value of 1 to 5 and a weight average molecular weight of 2500 to 10000 g.mol-1. Alternatively, said surfactant SI comprising a polyethylene glycol segment and a polypropylene glycol segment, has an HLB value of 10 to 15 and a weight average molecular weight of 500 to 2500 g.mol-1. Use

[0083] The copolymer as described in the present application can be used in numerous applications. Thus, said copolymer can be used as a binder for an electrode (cathode or anode) or as a coating for a separator.

[0084] Said copolymer according to the present invention can be used as a binder for an electrode. Thus, according to another aspect, the present invention provides an electrode composition comprising said copolymer according to the present invention, an active material and optionally a conductive agent.

[0085] In a preferred embodiment, the electrode composition has the following mass composition:

[0086] a. 50% to 99.9% of active material, preferably 50% to 99%,

[0087] b. 25% to 0% conductive agent, preferably 25% to 0.5%,

[0088] c. 25% to 0.05% of said binder according to the invention, preferably 25% to 0.5%,

[0089] d. 0% to 5% of at least one additive chosen from the group consisting of a plasticizer, an ionic liquid, a dispersing agent for conductive additive, and a flow aid;

[0090] the sum of all these percentages being 100%.

[0091] The conductive agents in the electrode are composed of one or more materials that can enhance conductivity. Some examples include carbon blacks such as acetylene black, Ketjen black; carbon fibers, such as carbon nanotube, carbon nanofiber, vapor-grown carbon fiber; metal powders such as SUS powder, and aluminum powder.

[0092] The active materials in the electrode compositions are materials that are capable of storing and releasing lithium ions.

[0093] In a preferred embodiment, said electrode is a negative electrode. In particular, for a negative electrode, said active material is selected from the group consisting of a lithium alloy, lithium metal, a metal oxide, a carbon material such as graphite or hard carbon, silicon, a silicon alloy and Li4TiO12. The shape of the negative electrode active material is not particularly limited but is preferably particulate.

[0094] In another preferred embodiment, said electrode is a positive electrode. Preferably, for a positive electrode, said active material is selected from the group consisting of LiCoO2, Li(Ni, Co, AI)O2, Li(l+ x), NiaMnbCoc (x represents a real number of 0 or more, a = 0.8, 0.6, 0.5, or 1 / 3, b = 0.1, 0.2, 0.3, or 1 / 3, c = 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, a Li Mn spinel substituted by a different element having a composition represented by Lil+xMn2-x-yMyO4, M representing at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, x and y independently representing a real number between 0 and 2, lithium titanate LixTiOy - x and y independently representing a real number between 0 and 2, and a lithium metal phosphate having a composition represented by LiMP04, M representing Fe, Mn, Co, or Ni. The shape of the positive electrode active material is not particularly limited but is preferably particulate. In addition, the surface of each of the materials described above can be coated. The coating material is not particularly limited as long as it has lithium ion conductivity and contains a material capable of being maintained as a coating layer on the surface of the active material. Examples of the coating material include LiNbO3, Li4Ti50i2, and Li3PO4.

[0095] Said electrode composition may be deposited on at least one face of a current collector to form said electrode. This deposition may be carried out in the presence of an organic solvent, water, a mixture of both or by a solvent-free process, i.e. by a dry coated electrode production process. Said organic solvent may be selected from the group consisting of n-methylpyrrolidone (NMP), dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), triethyl-phosphite (TEP), acetone, cyclopentanone, tetrahydrofuran, methyl ethylketone (MEK), methyl isobutyl ketone (MiBK), ethyl acetate (EA), butyl acetate (BA), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), gamma-butyrolactone and N-butylpyrrolidone; and mixtures thereof.

[0096] According to another aspect of the present invention, a Li-ion battery is provided. Preferably, the Li-ion battery comprises a positive electrode, a negative electrode and a separator, at least one electrode being an electrode according to the present invention.

[0097] According to another aspect of the present invention, said copolymer according to the present invention can be used as a coating in a separator arranged between two electrodes. Said separator according to the present invention comprises a coating comprising, preferably consisting of, said copolymer according to the present invention, optionally arranged on one or both faces of a porous support. In this case, the coating is used to coat the support of a separator, on at least one face, in the form of a monolayer or multilayers. There is no particular limitation in the choice of the support which is coated with the coating of the invention, as long as it is a porous substrate having pores. When it comprises several layers, the coating as described in the present invention is arranged on the external face of the support, that is to say on the face which will first be in contact with the electrolytic composition used in the battery.Advantageously, the application of the coating to the support is done by aqueous or solvent means. The porous substrate can take the form of a membrane or a fibrous fabric. When the porous substrate is . fibrous, it may be a nonwoven web forming a porous web, such as a web obtained by direct spinning or melt-blowing (of the "spunbond" or "melt-blown" type) or electro-spinning. Examples of porous substrates useful in the invention as a support include, but are not limited to: polyolefins, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyether sulfone, poly(phenylene oxide), poly(phenylene sulfide), polyethylene naphthalene or mixtures thereof. However, other heat-resistant engineering plastics may be used without particular limitation. Nonwoven materials made of natural and synthetic materials may also be used as the substrate of the separator.The porous substrate generally has a thickness of 1 to 50 µm, and are typically membranes obtained by extrusion and stretching (wet or dry process) or cast nonwovens. The porous substrate preferably has a porosity of between 5% and 95%. The average pore size (diameter) is preferably between 0.001 and 50 µm, more preferably between 0.01 and 10 µm. The support may also be aluminum or aluminum coated with a polymer layer.

[0098] In addition to said composition, the separator coating may contain inorganic particles that serve to form micropores in the coating (the interstices between inorganic particles). The addition of inorganic particles may also contribute to heat resistance or improve wettability. According to one embodiment, said coating comprises from 50 to 99 percent by weight of inorganic particles, based on the weight of the coating. These inorganic particles must be electrochemically stable (not subject to oxidation and / or reduction in the range of voltages used). In addition, powdered inorganic materials preferably have high ionic conductivity. Low density materials are preferred over higher density materials, since the weight of the produced battery can be reduced. The dielectric constant is preferably equal to or greater than 5.According to one embodiment, said inorganic particles are chosen from the group consisting of: BaTiO3, Pb(Zr,Ti)O3, Pb 1-x LaxZryO3 (0. <x<l, 0<y<l), pbmg3nb2 3)3,pbtio3, hafnie (hfo (hfo2), srtio 3, sno2, ceo2, mgo, nio, cao, zno, y2o3, bohémite (y-alo(oh)), a12o3, tio2, sic, zro2, silicate de bore, baso4, nano-argiles, ou leurs mélanges. le revêtement pour séparateur peut éventuellement comprendre 0 à 15 % en poids sur la base du polymère, et préférence 0,1 10 d'additifs, choisis parmi les épaississants, agents d'ajustement ph, anti-sédimentation, tensioactifs, mouillants, charges, anti-mousse promoteurs d'adhésion fugitive non. les charges mentionnées ici dans additifs sont différentes des particules inorganiques ci-dessus.

[0099] According to another aspect of the present invention, a Li-ion battery is provided. Preferably, the Li-ion battery comprises a positive electrode, a negative electrode and said separator according to the present invention.

[0100] According to another aspect of the present invention, said copolymer can be used in the preparation of a conductive polymer, a solid electrolyte for fuel cells, a hydrophilic coating, a hydrophobic coating or a UV-absorbing coating. Said copolymer can be used as an adhesive for a multilayer structure extruded in the form of a film, a sheet or a tube. Said copolymer can also be used as a coating on a metal. Examples

[0101] Example 1

[0102] A 250 ml high pressure reactor was purged with nitrogen. After that, it was filled at room temperature (24°C) with vinylidene fluoride until a pressure of 30 bar was reached. Then, 80 ml of water was added to the reactor and then it was heated to 88 °C, the pressure obtained was 44 bar. The reaction was initiated by the injection of potassium persulfate (0.14 g of KPS in 10 ml of water). A lipoic acid solution (0.1 g of lipoic acid sodium salt in 10 ml of water) was added at a flow rate of 0.5 ml / min on average. When no pressure drop was noticed, the reactor was cooled and opened. The product was isolated as a latex without coagulum. A white powder was then obtained after drying the corresponding latex. The solid content is 14% by weight. The incorporated lipoic acid content was quantified by 19F NMR (376 MHz, DMSO - characteristic peak at -68.51 ppm) and is 0.08 mol%.

[0103] Example 2

[0104] A 250 ml high pressure reactor was purged with nitrogen. After that, it was filled at room temperature (24°C) with vinylidene fluoride until a pressure of 30 bar was reached. Then, 80 ml of water was added to the reactor and then it was heated to 88 °C, the pressure obtained was 44 bar. The reaction was initiated by the injection of potassium persulfate (0.14 g of KPS in 10 ml of water). A lipoic acid solution (0.1 g of lipoic acid sodium salt in 20 ml of water) was added at a flow rate of 0.5 ml / min on average. When no pressure drop was noticed, the reactor was cooled and opened. The product was isolated as a latex without coagulum. A white powder was then obtained after drying the corresponding latex. The solid content is 22% by weight. The incorporated lipoic acid content was quantified by 19F NMR (376 MHz, DMSO - characteristic peak at -68.51 ppm) and is 0.05 mol%.

Claims

Claims

1. Copolymer comprising monomeric units derived from a fluorinated vinyl monomer M1 and monomeric units derived from a cyclic monomer M2 with 5, 6 or 7 members of formula (I) [CRaRb]n f 1 \ 1 ' S— s7 (I) in which n is an integer from 3 to 5; Ra and Rb are, independently of each other and independently for each unit n, selected from the group consisting of H, F, Ci-C2o alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; Ci-C2o fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C3-C20 cy-cloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type;C6-C2o aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; or the unit [CRaRb] forms a carbonyl group C=O or thiocarbonyl group C=S; characterized in that at least one of the substituents Ra or Rb of at least one unit n comprises a functional group -CO2H.;

2. Copolymer according to the preceding claim characterized in that at least one of the substituents Ra or Rb in at least one of the units n is of formula (III) -[C(R5)(R6)]mC(R7)(R8)-CO2H with m is an integer between 1 and 8; R5, R6 and R7 are independently of each other H, F, Ci-C5 alkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid, Ci-C5 fluoroalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide type,

3. cyano, ester, thioester, sulfonic acid, phosphoric acid; C3-C6 cy-cloalkyl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; C6 -C12 aryl substituted or not by one or more functional groups of carboxylic acid, amine, hydroxyl, ketone, aldehyde, amide, cyano, ester, thioester, sulfonic acid, phosphoric acid type; and a polymeric hydrocarbon chain; R8 is selected from the group consisting of H, C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type. Copolymer according to any one of the preceding claims, characterized in that said monomer M2 is of formula (I) MY

4.

5. (h wherein R5 and R6 are independently of each other H, C1-C5 alkyl, C3-C6 cycloalkyl, C6-C12 aryl or C1-C5 fluoroalkyl; R8 is selected from the group consisting of H and C1-C5 alkyl substituted or not by one or more functional groups of acid, amine, hydroxyl or ketone type; m is an integer between 1 and 6. Copolymer according to any one of the preceding claims, characterized in that said monomer M2 is lipoic acid. Copolymer according to any one of the preceding claims, characterized in that said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), CF2 =CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO 2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluo- roisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene.

6. Copolymer according to any one of the preceding claims, characterized in that said monomer M1 is vinylidene fluoride.

7. Copolymer according to the preceding claim characterized in that it comprises units of formula (II) -CH2CF2-S-[C(Ra)(Rb)]nSC(R1)(R2)C(R3)(R4)- with n, Ra and Rb as defined according to any one of the preceding claims 1 to 3; and R1, R2, R3 and R4 are independently of each other selected from the group consisting of H, F, Cl and

8. Cr3. Copolymer according to any one of the preceding claims, characterized in that it comprises monomeric units derived from a monomer M1 being vinylidene fluoride and said copolymer also comprises monomeric units derived from a monomer M3 selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1 CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene,trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro- 1-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, me-, lauryl acrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate, hydroxyethylhexyl methacrylate, acryloyloxy propylsuccinate and combinations thereof.

9. Process for producing a copolymer according to any one of the preceding claims, characterized in that it comprises a step a) of polymerization of a fluorinated monomer M1 in the presence of a cyclic monomer M2 with 5, 6 or 7 members of formula (I) [CR3Rb]n s........ s.... (0 as defined in any one of the preceding claims 1 to 4 and an initiator, characterized in that said monomer M2 is added in step a) in the form of a solution, preferably aqueous, the concentration of which is greater than or equal to 5 g / l.

10. Method according to the preceding claim, characterized in that step a) is carried out at a temperature above 40°C and a pressure of 10 to 120 bara.

11. A process according to any one of claims 9 or 10 characterized in that said monomer M1 is selected from the group consisting of vinylidene fluoride, vinyl fluoride, trifluoroethylene, chloro-trifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoro-propylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2 =CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO 2F, the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R'CH2OCF=CF2 in in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene,chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-l-propene.,

12. A method according to any one of the preceding claims 9 to 11.

13.

14.

15.

16.

17. characterized in that said monomer Ml is vinylidene fluoride. Process according to any one of the preceding claims 9 to 12, characterized in that step a) is carried out in the presence of a monomer M3 selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, perfluoro(1,3-dioxole), perfluoro(2,2-dimethyl-1,3-dioxole), the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, the monomer of formula CF2=CFOCF2CF2SO2F, the monomer of formula F(CF2)nCH2 OCF=CF2 in which n is 1, 2, 3, 4 or 5, the monomer of formula R1 CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4, the monomer of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene,perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro- 1-propene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, methacrylate amyl, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, hydroxyethylhexyl acrylate, hydroxyethylhexyl methacrylate,acryloyloxy propylsuccinate and combinations thereof., Electrode binder or separator coating comprising said copolymer according to any one of claims 1 to 8. Electrode or separator comprising said copolymer according to any one of claims 1 to 8. Battery, preferably lithium-ion, comprising said electrode or said separator according to the preceding claim. Use of said copolymer according to any one of the claims 1 to 8 for the preparation of a conductive polymer, a solid electrolyte for fuel cells, a hydrophilic coating, a hydrophobic coating or a UV-absorbing coating; or as an adhesive for a multi-layer structure extruded in the form of a film, a sheet or a tube; or said copolymer is used as a coating on a metal.