Monolayer with improved adhesive strength on metal surfaces

Abstract

The present invention relates to a monolayer having improved adhesive strength on a metal surface, comprising a fluoropolymer, a silicon-sulfur compound and an ethylene-based polymer consisting of carbon and hydrogen atoms and optionally oxygen and / or nitrogen atoms; an assembly comprising a substrate and the monolayer; a method of making the monolayer; a component comprising said monolayer and an apparatus comprising said component.

Description

Technical Field

[0001] The present invention relates to a single layer that has improved durable adhesive strength to a substrate, particularly a metal substrate, especially under conditions of moisture.

[0002] The present invention also relates to a method for preparing such a monolayer and the use of such a monolayer. Background Technology

[0003] Fluoropolymers, such as those containing polyvinylidene fluoride (PVDF), are known for their excellent dielectric and / or piezoelectric properties and are highly useful in a wide range of applications, particularly in electronics. In many applications, they are used as coatings or printed layers, requiring good adhesive properties.

[0004] However, fluoropolymers have very weak adhesion to metals, which is detrimental to their use in electronic applications, thus requiring metal substrates as the base material.

[0005] Several solutions have been developed to address this problem. One approach to improve adhesion between fluoropolymers and metal substrates is the use of grafted polymers. However, their sourcing and use are difficult and limited for large-scale, mass-production industrial applications.

[0006] Another solution involves developing and using specific adhesive layers to bond the fluoropolymer layer to a metal substrate. Such layers may include acrylic, epoxy, silane-based compounds, or thiol-based compounds. However, a major problem associated with this solution is that at least one additional layer (one or more) must be added between the fluoropolymer layer and the substrate as an adhesive layer, resulting in a multilayer structure. Multilayer structures have the following disadvantages: surface fragility, increased thickness, reduced flexibility and suppleness, delamination due to high pressure or high frequency (ultrasonic vibration), delamination due to moisture, additional manufacturing steps (printing or coating) that are difficult to handle when overlapping patterns or shapes, decreased dielectric properties / conductivity, delimitation due to cutting (edges), and delamination / peeling due to use (friction, bending, scratches, sweating, etc.). Therefore, multilayer structures are not suitable for various applications considering the harsh environments in which fluoropolymers are used.

[0007] One method to promote adhesion between fluoropolymers and metal substrates is to add sulfur-containing adhesion promoters to the fluoropolymers.

[0008] For example, EP 3638733 discloses a composition comprising a fluoropolymer and a silane agent, wherein the fluoropolymer comprises units derived from vinylidene fluoride and units derived from trifluoroethylene.

[0009] JP2010182994 describes an organic piezoelectric material suitable for high-frequency and broadband ultrasonic transducers, comprising an organic piezoelectric material layer containing a fluoropolymer and a material capable of forming covalent bonds with an electrode metal, the electrode metal including thiol groups as functional groups.

[0010] US20200239724 also describes a composition for preparing a passivation layer comprising a fluorinated copolymer and a thiol-based adhesion promoter.

[0011] However, these existing layers exhibit insufficient adhesion to metal substrates, especially after immersing the layer and substrate assembly in aqueous solutions. This issue is critical for end-use applications in harsh environments, particularly in water-contact applications such as outdoor applications, electronic or medical devices.

[0012] Therefore, there is a need for a monolayer containing a fluoropolymer that exhibits very high adhesive strength to substrates, particularly metal substrates, especially when the component is used in equipment that comes into contact with fluids such as water.

[0013] There is also a need for a monolayer comprising a fluoropolymer that exhibits very high adhesive strength to substrates, particularly metal substrates, while also being active. A monolayer that exhibits electroactive properties, particularly electro- or electronic, piezo- or dielectric, or electrostrictive properties, is particularly needed.

[0014] There is a particular need for this single layer that is also flexible. Summary of the Invention

[0015] Therefore, the present invention relates to a single layer comprising:

[0016] - Fluoropolymers,

[0017] -Silicon-sulfur compounds, and

[0018] - Ethylene polymers, which consist of carbon and hydrogen atoms, and optionally oxygen and / or nitrogen atoms.

[0019] In fact, the inventors discovered that fluoropolymers and silicon-sulfur compounds should be combined with ethylene polymers to achieve very good adhesion strength on a single-layer metal substrate, especially while maintaining the intended active properties of the fluoropolymers in contact with aqueous solutions.

[0020] The single layer according to the present invention has the following advantages:

[0021] - It is a single layer with at least two functions: adhesion to the substrate and electroactive properties (dielectric / semiconductor / piezoelectric / electric / electronic / electrostrictive);

[0022] -It is a flexible layer;

[0023] It enhances adhesion to substrates, particularly copper or gold; in particular, it improves adhesion even when the gold content in the substrate is low, meaning that adhesion is improved even when the gold layer quality is poor (e.g., lower gold purity levels, lower density, thinner thickness, and weaker homogeneity). Therefore, using the layer of this invention reduces the amount of gold required on the substrate surface, resulting in lower production costs.

[0024] - It is resistant to immersion in aqueous solutions; therefore, the single layer of the present invention is suitable for withstanding moisture, liquids and humid environments without the need for an additional intermediate layer, thereby avoiding dielectric loss at the fluoropolymer layer / substrate interface;

[0025] - It can be applied to conductive substrates such as electrodes or conductive plates, especially copper, gold, stainless steel, palladium, aluminum and their mixtures.

[0026] In particular, the inventors were surprised to find that adding silicon-sulfur compounds and ethylene-based polymers to fluoropolymers could maintain electroactive properties. Indeed, specific applications require high levels of dielectric properties, such as dielectric constant. Fluoropolymers can achieve such performance levels, but performance is expected to decline once adhesive accelerators are added. Conversely, this invention allows for the use of non-dielectric adhesive accelerators to improve layer adhesion to the substrate while maintaining electroactive properties such as dielectric properties.

[0027] Fluoropolymers

[0028] The single layer of the present invention comprises at least one fluoropolymer.

[0029] Fluoropolymers are polymers based on fluorocarbon compounds, meaning they contain several carbon-fluorine bonds.

[0030] Fluoropolymers contain units derived from fluorinated monomers (fluorinated monomers). Fluorinated monomers contain at least one carbon-fluorine bond.

[0031] These fluorinated monomers are preferably selected from:

[0032] Fluorinated monomers of formula (I)

[0033] C(X1)(X2)=C(X3)(X4)(I),

[0034] X1, X2, X3 and X4 are each independently selected from H, Cl, Br, F, I and C1-C6 straight-chain or branched alkyl groups, preferably methyl or ethyl, and the C1-C6 straight-chain or branched alkyl groups are optionally partially or completely halogenated, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

[0035] - A perfluoro(alkyl vinyl ether) of the formula Rx-O-CF=CF2, wherein Rx is C1-C8, preferably C1-C4 straight-chain or branched alkyl, such as perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE).

[0036] A perfluoro(meth)acrylate of the formula Ry-O-(O)C-CF=CF2, wherein Ry is H or C1-C8, preferably C1-C4 straight-chain or branched alkyl.

[0037] A fluoro(meth)acrylate of the formula Rz-O-(O)C-CH=CH2, wherein Ry is a C1-C8, preferably C1-C4, straight-chain or branched alkyl group, and has at least one, preferably three, fluorine atoms.

[0038] -C3-C6 perfluorocycloolefins (tetrafluorocyclopropylene, hexafluorocyclobutene, octafluorocyclopentene, decafluorocyclohexene),

[0039] - Perfluorinated (1,3-m-dioxacyclopentene);

[0040] - Perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD)

[0041] - A fluorinated monomer of the formula CF2=C(F)O-CF2CF(CF3)-O-CF2CF2-X, wherein X is CO2H, CH2OH, CO2CH3, SO2F, CH2OPO3H or CH2OCN.

[0042] Fluorine-containing monomers of the formula CF2=C(F)-O-CF2CF2SO2F,

[0043] A fluorinated monomer of the formula R-CH2-O-CF=CF2, where R is H or F(CF2). m -, where m is 1, 2, or 3.

[0044] A fluorinated monomer of the formula R'-O-CF=CH2, where R' is F(CF2). n -, where n is 1, 2, 3, or

[0045] -Equation F(CF2) z The fluorinated monomer CH2-O-CF=CF2, wherein z is 1, 2, 3, 4 or 5.

[0046] Fluoropolymers preferably contain units of fluorinated monomers derived from formula (I).

[0047] Preferably, in formula (I), X1, X2, X3 and X4 are each independently selected from H, F, Cl, I, Br, or optionally contain one or more methyl groups with substituents selected from F, Cl, I and Br. More preferably, X1, X2, X3 and X4 are each independently selected from H, F, Cl, Br or optionally contain one or more methyl groups with substituents selected from F, Cl and Br. Even more preferably, X1, X2, X3 and X4 are each independently selected from H, F, Cl or optionally contain one or more methyl groups with substituents selected from F and Cl. Advantageously, X1, X2, X3 and X4 are each independently selected from H, F and optionally contain one or more methyl groups with F, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

[0048] According to one embodiment, X1, X2, X3 and X4 are each independently selected from H, F, Cl, I and Br, preferably X1, X2, X3 and X4 are each independently selected from H, F, Cl and Br, more preferably X1, X2, X3 and X4 are each independently selected from H, F and Cl, and even more preferably X1, X2, X3 and X4 are each independently selected from H and F, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

[0049] According to another embodiment, one and only one of X1, X2, X3 and X4 is selected from Cl, I and Br, preferably Cl, while the others of X1, X2, X3 and X4 are independently selected from H, F or C1-C3 alkyl, preferably C1-C2 alkyl, more preferably methyl, wherein the alkyl or methyl group optionally has one or more fluorine substituents, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

[0050] Examples of fluorinated monomers of formula (I) are: ethylene fluoride (ethylene fluoride), vinylidene fluoride (VDF), 1,2-difluoroethylene, trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trifluoropropylene such as 3,3,3-trifluoropropylene, tetrafluoropropylene such as 2,3,3,3-tetrafluoropropylene or 1,3,3,3-tetrafluoropropylene, pentafluoropropylene such as 1,1,3,3,3-pentafluoropropylene or 1,2,3,3,3-pentafluoropropylene, hexafluoropropylene, hexafluoroisobutylene, 3,3,3-trifluoro-2-(trifluoromethyl)propene, perfluorobutylethylene (PFBE), bromofluoroethylene (1-bromo-1-fluoroethylene or 1-bromo-2-fluoroethylene), bromodifluoroethylene (1-bromo-2,2-difluoroethylene or 1-bromo-1,2-difluoroethylene), bromotrifluoroethylene (cis or trans form of 1- Bromo-3,3,3-trifluoropropene or 2-bromo-3,3,3-trifluoropropene), chlorofluoroethylene (CFE) (1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene), dichlorofluoroethylene (1-chloro-2,2-difluoroethylene or 1-chloro-1,2-difluoroethylene), chlorotrifluoroethylene (CTFE) (cis or trans form of 1-chloro-3,3,3-trifluoropropene or 2-chloro-3,3,3- (trifluoropropylene), bromotrifluoropropylene, chlorotrifluoropropylene, (1 or 2 or 3 or 4)-bromo-(1 or 2)-fluorobutene, (1 or 2 or 3 or 4)-chloro-(1 or 2)-fluorobutene, (2 or 3 or 4)-chloro-1,1-difluorobutene, (2 or 3 or 4)-bromo-1,1-difluorobutene, (3 or 4)-bromo-1,1,2-trifluorobutene, (3 or 4)-chloro-1,1,2-trifluorobutene.

[0051] Fluoropolymers can be homopolymers of fluorinated monomers, or they can be obtained by copolymerizing fluorinated monomers with one or more other fluorinated monomers and / or other monomers that are not fluorinated monomers to form copolymers.

[0052] A copolymer is a polymer derived from more than one monomer. The copolymers of the present invention are in particular comonomers of two monomers (dimers) or three different monomers (terpolymers).

[0053] Preferably, the total molar content of fluorinated monomers in the fluorinated polymer is 40% to 100% relative to the total molar content of monomers in the fluorinated polymer, more preferably 50% to 95%, and even more preferably 60% to 90%.

[0054] The monomers that are non-fluorinated and can be copolymerized with fluorinated monomers are preferably selected from non-fluorinated olefinic monomers (ethylenic monomers).

[0055] An alkene monomer is a molecule containing at least one carbon-carbon double bond. Preferably, the nonfluorinated alkene monomer is as described in the formula C(R1)(R2) = C(R3)(R4), wherein R1, R2, R3, and R4 are independently selected from the following groups: hydrogen atom, aryl (preferably phenyl), C1-C10 (preferably C1-C4) straight-chain or branched or cyclic saturated or unsaturated hydrocarbon group, optionally also containing ether, ester, nitrile, carboxyl, amine, and / or amide groups (one or more), including the possibility that two groups from R1, R2, R3, and R4 form a 5-, 6-, or 7-membered ring.

[0056] Advantageously, the nonfluorinated olefin monomer is selected from ethylene, propylene, methyl or ethyl vinyl ether, vinyl ester, allyl glycidyl ether, (meth)acrylic acid, (m)ethyl (meth)acrylate and vinyl acetate.

[0057] Preferably, the molar content (or molar ratio) of the first fluorinated monomer (especially when the first fluorinated monomer is vinylidene fluoride) in the fluoropolymer is 40% to 98%, more preferably 50% to 90%, more preferably 60% to 80%, and even more preferably 60% to 70%. Preferably, the molar content of the second fluorinated monomer in the fluoropolymer is 2% to 60% relative to the total molar content of the fluoropolymer monomers, more preferably 10% to 50%, more preferably 20% to 40%, and even more preferably 30% to 40%.

[0058] According to one embodiment, the fluoropolymer is a dimer of two different fluorinated monomers (i.e., a first fluorinated monomer and a second fluorinated monomer). The fluorinated monomers are each described independently as described above.

[0059] Preferably, the fluoropolymer is a terpolymer of at least three different fluorinated monomers (i.e., a first fluorinated monomer, a second fluorinated monomer, and a third fluorinated monomer). Each fluorinated monomer is independently described as described above.

[0060] Ternary copolymers are particularly advantageous because they allow for high electroactive properties, especially high dielectric properties, as well as exceptionally high piezoelectric properties.

[0061] Fluoropolymers may comprise a first fluorinated monomer unit and a second fluorinated monomer unit, or may be composed of a first fluorinated monomer unit and a second fluorinated monomer unit. Fluoropolymers may also comprise a first fluorinated monomer unit, a second fluorinated monomer unit, and a third fluorinated monomer unit, or may be composed of a first fluorinated monomer unit, a second fluorinated monomer unit, and a third fluorinated monomer unit.

[0062] Specifically, the fluoropolymer is a copolymer of vinylidene fluoride (as the first fluorinated monomer) and at least one second fluorinated monomer that is a fluorinated monomer as described above, provided that the second fluorinated monomer is different from vinylidene fluoride. More preferably, the fluoropolymer is a terpolymer of vinylidene fluoride (as the first fluorinated monomer) with a second fluorinated monomer and a third fluorinated monomer, provided that the second fluorinated monomer and the third fluorinated monomer are different from vinylidene fluoride and are different from each other.

[0063] Fluoropolymers may comprise vinylidene fluoride units and second fluorinated monomer units (and third fluorinated monomer units, if present), or may consist of vinylidene fluoride units and second fluorinated monomer units (and third fluorinated monomer units, if present).

[0064] The second fluorinated monomer is preferably a fluorinated monomer of formula (I) as described above.

[0065] If present, the third fluorinated monomer is preferably a fluorinated monomer of formula (I) as described above.

[0066] Preferably, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a second fluorinated monomer of formula (I), preferably a dimer, wherein X1, X2, X3 and X4 are each independently selected from H, F, Cl, I, Br or optionally contain one or more methyl groups selected from F, Cl, I and Br, preferably X1, X2, X3 and X4 are each independently selected from H, F, Cl, Br or optionally contain one or more methyl groups selected from F, Cl and Br, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom, and provided that the second fluorinated monomer is different from vinylidene fluoride.

[0067] More preferably, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a second fluorinated monomer of formula (I), preferably a dimer, wherein X1, X2, X3 and X4 are each independently selected from H, Cl, F or optionally contain one or more methyl groups of F or Cl, preferably X1, X2, X3 and X4 are each independently selected from H, F or optionally contain one or more methyl groups of F, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom, and provided that the second fluorinated monomer is different from vinylidene fluoride.

[0068] According to one embodiment, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a second fluorinated monomer of formula (I), preferably a dimer, wherein X1, X2, X3 and X4 are each independently selected from H, F, Cl, I or Br, preferably from H, F, Cl or Br, more preferably from H, F and Cl, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom, and provided that the second fluorinated monomer is different from vinylidene fluoride.

[0069] According to another embodiment, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a second fluorinated monomer of formula (I), preferably a dimer, wherein one and only one of X1, X2, X3 and X4 is selected from Cl, I and Br, preferably Cl and Br, and the others of X1, X2, X3 and X4 are independently selected from H, F or C1-C3 alkyl, preferably C1-C2 alkyl, more preferably methyl, said alkyl or methyl optionally having one or more fluorine substituents, advantageously, the others of X1, X2, X3 and X4 are independently selected from H and F, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom, and the second fluorinated monomer is different from vinylidene fluoride.

[0070] Preferably, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a second fluorinated monomer, preferably a dimer, wherein the second fluorinated monomer is selected from vinylidene fluoride (vinyl fluoride), vinylidene fluoride (VDF), 1,2-difluoroethylene, trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trifluoropropylene such as 3,3,3-trifluoropropylene, tetrafluoropropylene such as 2,3,3,3-tetrafluoropropylene or 1,3,3,3-tetrafluoropropylene, pentafluoropropylene such as 1,1,3,3,3-pentafluoropropylene or 1,2,3,3,3-pentafluoropropylene, hexafluoropropylene, hexafluoroisobutylene, 3,3-3-trifluoro-2-(trifluoromethyl)propene, perfluorobutylethylene (PFBE), bromofluoroethylene (1-bromo-1-fluoroethylene or 1-bromo-2-fluoroethylene), bromodifluoroethylene (1-bromo-2,2-difluoroethylene or 1-bromo-1,2-difluoroethylene), bromo... Trifluoroethylene (cis or trans form of 1-bromo-3,3,3-trifluoropropene or 2-bromo-3,3,3-trifluoropropene), chlorofluoroethylene (CFE) (1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene), dichlorofluoroethylene (1-chloro-2,2-difluoroethylene or 1-chloro-1,2-difluoroethylene), chlorotrifluoroethylene (CTFE) (cis or trans form of 1-chloro-3,3,3-trifluoropropene or 2-... Chloro-3,3,3-trifluoropropene), bromotrifluoropropene, chlorotrifluoropropene, (1 or 2 or 3 or 4)-bromo-(1 or 2)-fluorobutene, (1 or 2 or 3 or 4)-chloro-(1 or 2)-fluorobutene, (2 or 3 or 4)-chloro-1,1-difluorobutene, (2 or 3 or 4)-bromo-1,1-difluorobutene, (3 or 4)-bromo-1,1,2-trifluorobutene, (3 or 4)-chloro-1,1,2-trifluorobutene.

[0071] According to the most preferred embodiment, the fluoropolymer is a copolymer of vinylidene fluoride and (at least) a fluorinated monomer, preferably a dimer, wherein the fluorinated monomer is selected from hexafluoropropylene, chlorofluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene and trifluoroethylene, preferably selected from chlorofluoroethylene, chlorotrifluoroethylene and trifluoroethylene.

[0072] According to a preferred embodiment, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer of formula (I), and a third fluorinated monomer of formula (I), wherein X1, X2, X3, and X4 are each independently selected from H, F, Cl, I, Br, or optionally contain one or more methyl groups selected from F, Cl, I, and Br, preferably X1, X2, X3, and X4 are each independently selected from H, F, Cl, Br, or optionally contain one or more methyl groups selected from F, Cl, and Br, provided that at least one of X1, X2, X3, and X4 contains at least one fluorine atom, and provided that the second and third fluorinated monomers are different from vinylidene fluoride and are different from each other.

[0073] More preferably, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer of formula (I), and a third fluorinated monomer of formula (I), wherein X1, X2, X3, and X4 are each independently selected from H, Cl, F, or optionally contain one or more methyl groups of F or Cl, preferably X1, X2, X3, and X4 are each independently selected from H, F, or optionally contain one or more methyl groups of F, provided that at least one of X1, X2, X3, and X4 contains at least one fluorine atom, and provided that the second and third fluorinated monomers are different from vinylidene fluoride and are different from each other.

[0074] According to one embodiment, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer of formula (I), and a third fluorinated monomer of formula (I), wherein X1, X2, X3, and X4 are each independently selected from H, F, Cl, I, or Br, preferably from H, F, Cl, or Br, more preferably from H, F, and Cl, provided that at least one of X1, X2, X3, and X4 contains at least one fluorine atom, and provided that the second and third fluorinated monomers are different from vinylidene fluoride and are different from each other.

[0075] According to another embodiment, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer of formula (I), and a third fluorinated monomer of formula (I), wherein one and only one of X1, X2, X3, and X4 is selected from Cl, I, and Br, preferably Cl and Br, and the others of X1, X2, X3, and X4 are independently selected from H, F, or C1-C3 alkyl, preferably C1-C2 alkyl, more preferably methyl, wherein the alkyl or methyl group optionally has one or more fluorine substituents, advantageously, the others of X1, X2, X3, and X4 are independently selected from H and F, provided that at least one of X1, X2, X3, and X4 contains at least one fluorine atom, and provided that the second and third fluorinated monomers are different from vinylidene fluoride and are different from each other.

[0076] Preferably, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer, and a third fluorinated monomer, wherein the second and third fluorinated monomers are independently selected from vinylidene fluoride (vinyl fluoride), vinylidene fluoride (VDF), 1,2-difluoroethylene, trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trifluoropropylene such as 3,3,3-trifluoropropylene, tetrafluoropropylene such as 2,3,3,3-tetrafluoropropylene or 1,3,3,3-tetrafluoropropylene, pentafluoropropylene such as 1,1,3,3,3-pentafluoropropylene or 1,2,3,3,3-pentafluoropropylene, hexafluoropropylene, hexafluoroisobutylene, 3,3-3-trifluoro-2-(trifluoromethyl)propene, perfluorobutylethylene (PFBE), bromofluoroethylene (1-bromo-1-fluoroethylene or 1-bromo-2-fluoroethylene), and bromodifluoroethylene (1-bromo-2,2-difluoroethylene or 1-bromo-1,2-difluoroethylene). 1-Bromo-3,3,3-trifluoropropene (cis or trans form) , bromotrifluoroethylene (1-bromo-3,3,3-trifluoropropene or 2-bromo-3,3,3-trifluoropropene), chlorofluoroethylene (CFE) (1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene), dichlorofluoroethylene (1-chloro-2,2-difluoroethylene or 1-chloro-1,2-difluoroethylene), chlorotrifluoroethylene (CTFE) (cis or trans form) , bromotrifluoropropene or 2-bromo-3,3,3-trifluoropropene or 2-bromo-3,3,3-trifluoropropene 2-Chloro-3,3,3-trifluoropropene), bromotrifluoropropene, chlorotrifluoropropene, (1 or 2 or 3 or 4)-bromo-(1 or 2)-fluorobutene, (1 or 2 or 3 or 4)-chloro-(1 or 2)-fluorobutene, (2 or 3 or 4)-chloro-1,1-difluorobutene, (2 or 3 or 4)-bromo-1,1-difluorobutene, (3 or 4)-bromo-1,1,2-trifluorobutene, (3 or 4)-chloro-1,1,2-trifluorobutene.

[0077] According to the most preferred embodiment, the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer, and a third fluorinated monomer, wherein the second and third fluorinated monomers are independently selected from hexafluoropropylene, chlorofluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, and trifluoroethylene, preferably from chlorofluoroethylene, chlorotrifluoroethylene, and trifluoroethylene.

[0078] Preferably, the terpolymer is a polymer of vinylidene fluoride, trifluoroethylene (as the second fluorinated monomer), and chlorotrifluoroethylene (P(VDF-TrFE-CTFE)) (as the third fluorinated monomer), or a terpolymer of vinylidene fluoride, trifluoroethylene (as the second fluorinated monomer), and chlorofluoroethylene (P(VDF-TrFE-CFE)) (as the third fluorinated monomer).

[0079] Preferably, the molar content (or molar ratio) of vinylidene fluoride in the fluoropolymer is 40% to 98%, more preferably 50% to 80%, more preferably 60% to 75%, and even more preferably 60% to 70%. Preferably, the molar content of the second fluorinated monomer in the fluoropolymer is 15% to 45% relative to the total molar content of the fluoropolymer monomers, more preferably 20% to 40%, and even more preferably 25% to 30%. Preferably, the molar content of the third fluorinated monomer in the fluoropolymer is 1% to 15% relative to the total molar content of the fluoropolymer monomers, more preferably 3% to 12%, and even more preferably 5% to 10%.

[0080] The weight-average molar mass (Mw) of the fluoropolymer is preferably at least 100,000 g·mol⁻¹. -1 Preferably at least 200,000 g·mol⁻¹ -1 More preferably at least 300,000 g·mol⁻¹ -1 Even more preferably, at least 400,000 g·mol⁻¹ -1 Preferably, it is 200,000 to 1,000,000 g·mol⁻¹ -1 Molecular weight distribution can be determined by size exclusion chromatography (SEC).

[0081] Relative to the total mass of the monolayer, the monolayer of the present invention preferably comprises 80% to 99.9% by mass, more preferably 90% to 99.8% by mass, and more preferably 95% to 98.5% by mass of a fluoropolymer.

[0082] silicon sulfide compounds

[0083] A silicon-sulfur compound is a compound containing at least one silicon atom and at least one sulfur atom, preferably at least one silyl group and / or at least one nitrogen-silyl group, and at least one sulfur atom, more preferably at least one silyl group and at least one sulfur atom.

[0084] The silane group is preferably a group of the formula -Si(Ra)(Rb)(Rc), wherein Ra, Rb and Rc are each independently selected from H, OH, Alk and -O-Alk, and Alk is a C1-C8 straight-chain or branched alkyl group, preferably selected from OH, Alk and -O-Alk.

[0085] The silazane group contains at least a Si-N bond, and preferably contains at least one nitrogen atom covalently bonded to a hydrogen atom and two silicon atoms (-Si-NH-Si- group).

[0086] Preferably, Ra, Rb, and Rc are each independently selected from Alk and -O-Alk.

[0087] Preferably, Alk (or Alk that is independently a -O-Alk group) is a C1-C4 straight-chain or branched alkyl group, more preferably methyl or ethyl, and even more preferably methyl.

[0088] Preferably, in the silicon-sulfur compound, the sulfur atom of the thiol functional group is not directly connected to the silicon atom.

[0089] More preferably, the sulfur compound of the silicon-sulfur compound exists in the form of a -S-(Rd) group, wherein (Rd) is selected from H and an organic moiety comprising 1 to 30 carbon atoms and at least one nitrogen atom and / or at least one oxygen atom. Preferably, (Rd) is selected from H and an organic moiety comprising 1 to 30 carbon atoms, hydrogen atoms, and one or more nitrogen atoms and / or one or more oxygen atoms.

[0090] Preferably, the silicon-sulfur compound is as shown in formula (II):

[0091] (Rd)S–Rw–Si(Ra)(Rb)(Rc)(II)

[0092] Rw is a straight-chain, branched, or cyclic group comprising 1 to 18 carbon atoms and optionally one or more oxygen atoms and / or nitrogen atoms, wherein Ra, Rb, Rc, and Rd are as described above according to any embodiment. More preferably, Rw is a C1-C12, preferably C1-C8, preferably C1-C6, preferably C1-C4, more preferably C2-C4 straight-chain or branched (preferably straight-chain) alkyl or alkylene group, preferably alkyl.

[0093] According to a preferred embodiment, Rd is H. According to this embodiment, the silane-sulfur compound is a mercaptosilane, i.e., a compound containing at least one silane group and at least one thiol functional group (-SH).

[0094] Preferably, the silicon-sulfur compound is not a polymer.

[0095] Preferably, the molecular weight of silicon-sulfur is less than 800 g·mol⁻¹. -1 Preferably less than 600 g·mol⁻¹ -1 Preferably less than 400 g·mol⁻¹ -1 Preferably less than 250 g·mol⁻¹ -1 Preferably 80 g·mol -1 Up to 800g.mol -1 .

[0096] Non-limiting examples of silicon-sulfur compounds are:

[0097] -Thiooctanoic acid, S-[3-(triethoxysilyl)propyl] ester, the product of the reaction of 2-methyl-1,3-propanediol and 3-(triethoxysilyl)-1-propanethiol (EC No.: 485-270-1);

[0098] -3-(triethoxysilyl)propanethiol (CAS No. 14814-09-6);

[0099] 3-(dimethoxymethylsilyl)-2-methylpropanethiol (CAS No. 14857-92-2);

[0100] -3-(methoxydimethylsilyl)propanethiol (CAS No. 14857-97-7);

[0101] - Hexamethylene diisocyanate, oligomer, product of reaction with 3-aminopropylmethylamine, trimethylacetaldehyde and 3-trimethoxysilylpropane-1-thiol (CAS No. 161278-26-8).

[0102] - Propoxylated pentaerythritol, the reaction product of 3-isocyanato-3,5,5-trimethylcyclohexyl isocyanate and 3-trimethoxysilylpropane-1-thiol (CAS No. 161308-00-5).

[0103] - Hexamethylene diisocyanate, trimer, reaction product with (3-aminopropyl)methylamine, benzaldehyde and 3-trimethoxysilylpropane-1-thiol (CAS No. 162491-90-9);

[0104] 2-Methyl-3-(triethoxysilyl)propanethiol (CAS No. 17980-28-8);

[0105] -2-(triethoxysilyl)ethanethiol (CAS No. 18236-15-2);

[0106] -(trimethylsilyl)methyl thiocyanate (CAS No. 18293-51-1);

[0107] - Trimethylsilyl isothiocyanate (CAS No. 2290-65-5);

[0108] -3-(dimethoxymethylsilyl)propanethiol (CAS No. 31001-77-1);

[0109] -1-Allyl-3-[3-(triethoxysilyl)propyl]thiourea (CAS No. 42168-36-5);

[0110] -3-Trimethoxysilylpropane-1-thiol (CAS No. 4420-74-0);

[0111] -4-(triethoxysilyl)butane-2-thiol (CAS No. 57640-10-5);

[0112] -2-[3-(trimethoxysilyl)propyl]isothiourea chloride (CAS No. 58505-58-1);

[0113] -3-[tris(2-ethoxyethoxy)silyl]propanethiol (CAS No. 67724-41-8);

[0114] -2-(trimethoxysilyl)ethanethiol (CAS No. 7538-45-6);

[0115] A mixture of S-(3-trimethoxysilyl)propyl19-isocyanate-11-(6-isocyanate-hexyl)-10,12-dioxo-2,9,11,13-tetraazanonadecane sulfate and S-(3-(trimethoxysilyl)propyl17-isocyanate-9-(isocyanate-hexyl-aminocarbonyl)-10-oxo-2,9,11-triazaheptadecane sulfate (CAS No. 85702-90-5);

[0116] -1,3-Dibutyl-2-[3-(triethoxysilyl)propyl]isothiourea chloride (CAS No. 90210-34-7);

[0117] -1,3-Diphenyl-2-[3-(triethoxysilyl)propyl]isothiourea, monohydrochloride (CAS No. 90210-35-8);

[0118] -3-[tris(decoxy)silyl]propanethiol (CAS No. 93777-94-7);

[0119] 1-Methyl-3-(triethoxysilyl)propyl thiocyanate (CAS No. 94087-37-3);

[0120] 2-Methyl-3-(triethoxysilyl)propyl thiocyanate (CAS No. 94087-38-4);

[0121] -3-[tri(octyloxy)silyl]propanethiol (CAS No. 94291-66-4).

[0122] Advantageous examples of silicon-sulfur compounds include:

[0123] -3-(triethoxysilyl)propanethiol (CAS No. 14814-09-6);

[0124] 3-(dimethoxymethylsilyl)-2-methylpropanethiol (CAS No. 14857-92-2);

[0125] -3-(methoxydimethylsilyl)propanethiol (CAS No. 14857-97-7);

[0126] 2-Methyl-3-(triethoxysilyl)propanethiol (CAS No. 17980-28-8);

[0127] -2-(triethoxysilyl)ethanethiol (CAS No. 18236-15-2);

[0128] -3-(dimethoxymethylsilyl)propanethiol (CAS No. 31001-77-1);

[0129] -3-Trimethoxysilylpropane-1-thiol (CAS No. 4420-74-0);

[0130] -4-(triethoxysilyl)butane-2-thiol (CAS No. 57640-10-5);

[0131] -3-[tris(2-ethoxyethoxy)silyl]propanethiol (CAS No. 67724-41-8);

[0132] -2-(trimethoxysilyl)ethanethiol (CAS No. 7538-45-6);

[0133] -3-[tris(decoxy)silyl]propanethiol (CAS No. 93777-94-7);

[0134] -3-[tri(octyloxy)silyl]propanethiol (CAS No. 94291-66-4).

[0135] Relative to the total mass of the monolayer, the monolayer of the present invention preferably contains 0.05% to 10% by mass, more preferably 0.10% to 5% by mass, more preferably 0.50% to 3.0% by mass, and more preferably 0.75% to 2.5% by mass of a silicon-sulfur compound.

[0136] Ethylene polymers

[0137] The monolayer of the present invention comprises at least one ethylene polymer consisting of carbon atoms and hydrogen atoms, and optionally oxygen atoms and / or nitrogen atoms.

[0138] Vinyl polymers contain units derived from one or more vinyl monomers.

[0139] Vinyl monomers are small organic molecules that contain at least one carbon-carbon double bond.

[0140] Preferably, the vinyl monomer has the following formula: C(X)(X')=C(X”)(X”'), wherein X, X', X” and X”' are independently selected from hydrogen atoms, OH groups, COOH groups, CN groups, aryl groups, saturated or unsaturated hydrocarbon groups comprising 1 to 10 carbon atoms, preferably 2 to 10 carbon atoms, and the aryl or hydrocarbon group optionally further comprises OH groups, ester groups, carboxyl groups, amino groups, nitrile groups and / or amide groups.

[0141] The vinyl monomer is preferably selected from alkenyl monomers in C2-C8 (preferably C2-C4), diene monomers in C4-C12, acrylate monomers, styrene monomers, vinyl alcohol, vinyl acetate, acrylamide monomers, maleic acid, and acrylonitrile.

[0142] Ethylene polymers can also be elastomers, such as, but not limited to, copolymers of acrylonitrile and ethylene, or terpolymers, or ethyl monomers, acrylate monomers, and other vinyl monomers.

[0143] Ethylene polymers can also be PVA copolymers, copolymers of vinyl acetate and acrylic acid, or polyacrylamide.

[0144] Preferably, the ethylene polymer is an acrylate polymer.

[0145] Acrylic polymers are polymers based on acrylic acid or acrylic acid derivatives (or derived from acrylic acid or acrylic acid derivatives), and therefore are polymers containing units derived from acrylate monomers.

[0146] Acrylic ester monomers are molecules containing at least one ester functional group and an unsaturated C=C double bond with a carbon atom directly attached to the acid or ester functional group. In other words, acrylate monomers are vinyl monomers containing an ester group, which is a double bond of two carbon atoms directly attached to a carbonyl group. Acrylic ester polymers belong to the vinyl polymer family.

[0147] According to the present invention, acrylic acid is included in the definition of acrylate monomers.

[0148] Preferably, the acrylate polymer comprises units of acrylate monomers derived from formula (III).

[0149]

[0150] Xa and Xb are independently selected from H, -CN groups, and C1-C8 straight-chain, branched, or cyclic saturated or unsaturated groups containing 1 to 8 carbon atoms, and Xc is selected from H, benzyl, and straight-chain, branched, or cyclic saturated or unsaturated aliphatic or aromatic groups containing 1 to 24 carbon atoms, wherein the aliphatic or aromatic groups are optionally substituted by at least one OH group and / or one COOH group and / or optionally interrupted by at least one -O- atom.

[0151] Preferably, Xa and Xb are independently selected from H and C1-C8 straight-chain or branched alkyl groups.

[0152] Preferably, Xa = H.

[0153] Preferably, Xb = H, -CN group or C1-C2 alkyl, preferably H or C1-C2 alkyl, more preferably H or methyl.

[0154] Preferably, Xc is selected from:

[0155] -C1-C24, preferably C1-C16, more preferably C1-C8, even more preferably C1-C4 saturated, straight-chain or branched alkyl groups, advantageously methyl or ethyl; and

[0156] -–A–O–Rx group, wherein A is –CH2CH(OH)CH2– or –CH2CH(CH2OH)–, and Rx is a C10-C22 straight-chain or branched alkyl group.

[0157] More preferably, Xc is a saturated, straight-chain or branched alkyl group of C1-C24, preferably C1-C16, more preferably C1-C8, or even more preferably C1-C4, and advantageously is methyl or ethyl.

[0158] The acrylate monomer can be an acrylate having an additional methyl group linked to (Xb), where Xc is a methyl group. The acrylate monomer can also be a methacrylate. One of the most common methacrylate polymers is polymethyl methacrylate (PMMA).

[0159] Acrylic ester monomers, particularly ethyl acrylate, ethyl methacrylate, butyl acrylate, ethylhexyl acrylate or their derivatives.

[0160] The acrylate polymer can be a homopolymer of an acrylate monomer (preferably an acrylate monomer of formula (III)) or can be obtained by copolymerizing the acrylate monomer with one or more other acrylate monomers and / or other monomers (one or more) that are not acrylate monomers to form a copolymer.

[0161] For example, acrylate polymers can be copolymers of methyl acrylate and methyl methacrylate, ethyl acrylate and methyl acrylate, butyl acrylate and 2-ethylhexyl acrylate.

[0162] The acrylate polymer can also be an acrylonitrile-styrene (meth)acrylate terpolymer, a styrene-acrylonitrile copolymer with a grafted acrylic elastomer, or a copolymer of styrene and an acrylate monomer. Non-acrylate monomers that can be copolymerized with acrylate monomers are preferably selected from the vinyl monomers described above, provided that such vinyl monomers are non-acrylate monomers.

[0163] The non-acrylate monomers that can be copolymerized with acrylate monomers can be C2-C8 (preferably C2-C4) alkenyl monomers, C4-C12 diene monomers, styrene monomers, vinyl alcohol, vinyl acetate, acrylamide monomers, maleic acid, and acrylonitrile.

[0164] The acrylic monomer can be ethyl acrylate, butyl acrylate, ethylhexyl acrylate or their derivatives.

[0165] The vinyl (co)monomer is preferably as shown in the formula C(X)(X')=C(X”)(X”'), where X, X', X” and X”' are as described above.

[0166] Preferably, X = X' = H.

[0167] According to one embodiment, X = X' = H, X” is H or a C1-C2 alkyl group, preferably H, and X”' is –C6H5, –CN, –C(O)NH2, –NC4H6O, -C(O)NHC(CH3)3, -C(O)N(CH3)2, -C(O)NHC(CH3)2(CH2)4CH3 and -C(O)NHC(CH3)2CH2S(O)(O)OH.

[0168] According to another embodiment, X = X' = H, X” = H or C1-C2 alkyl, preferably H, X”' is -OC(O)-Xm, wherein Xm is a straight-chain or branched C1-C18 alkyl.

[0169] According to another embodiment, X = X' = H, X” = H or C1-C2 alkyl, preferably H, X”' is -OC(O)-Xm, wherein Xm is a straight-chain or branched C1-C18 alkyl.

[0170] Preferably, the ethylene polymers are not fluorinated; this means that the ethylene polymers do not contain any fluorine atoms.

[0171] According to one embodiment, the vinyl polymer is not sodium poly(meth)acrylate. In particular, the vinyl polymer is not a superabsorbent polymer. Specifically, the vinyl monomer is not a basic salt of acrylic acid or acrylate monomers.

[0172] Relative to the total mass of the monolayer, the monolayer of the present invention preferably contains 0.05% to 10.0% by mass, more preferably 0.10% to 8.0% by mass, more preferably 0.50% to 5.0% by mass, and more preferably 0.75% to 4.0% by mass of an ethylene polymer.

[0173] single layer

[0174] Preferably, the thickness of the single layer according to the present invention is 0.1-50 μm, more preferably 0.5-40 μm, more preferably 1.0-30 μm, more preferably 1.0-20 μm, and more preferably 2.0-10 μm.

[0175] Preferably, relative to the total mass of the monolayer, the total mass of the fluoropolymer, silicon sulfide compound and ethylene polymer in the monolayer is more than 80% by mass, preferably more than 90% by mass, more preferably more than 95% by mass, most preferably more than 98% by mass, and more preferably 80% to 99.99% by mass.

[0176] According to one embodiment, the monolayer is free of metal oxide particles, preferably free of metal, and more preferably free of inorganic crystals.

[0177] Preferably, the monolayer piezoelectric compound is essentially an organic (preferably polymeric) piezoelectric compound.

[0178] Preferably, the monolayer is an active monolayer, and more preferably an electroactive monolayer. An "active monolayer" or "electroactive monolayer" refers to a monolayer that possesses properties of responding to, interacting with, or annealing to an electric or magnetic field. Such active properties can encompass direct or inverse piezoelectric, electronic, dielectric, semiconductor, piezoelectric, electrical, and / or electrostrictive properties.

[0179] Specifically, the dielectric constant ε of the monolayer at 10 kHz r The value is 15-40 F / m, preferably 18-35 F / m, and more preferably 20-30 F / m.

[0180] Based on the method described in the example, the dielectric constant ε is determined specifically for monolayers with a thickness of 2.9–3.2 μm and a surface area of ​​2.0–8.0 mm². r .

[0181] In contrast to self-assembled monolayers (SAMs), monolayers exhibit strong interactions with the substrate to ensure adhesion and dielectric properties (self-assembled monolayers of organic molecules are spontaneously formed molecular assemblies adsorbed on a surface and organized in ordered domains of varying sizes. In some cases, the interactions between the molecules forming the monolayer and the substrate are weak).

[0182] The present invention also relates to a component comprising a substrate and a monolayer according to the invention, the monolayer being applied to at least one surface of the substrate or a portion thereof. The monolayer is in contact with at least one surface of the substrate. As a thin film, the monolayer may be applied wholly or partially to the substrate. The monolayer may be applied as a continuous or discontinuous surface, pattern, path, etc.

[0183] The substrate can be, in particular, glass, silicon, quartz, polymer materials, metals, or a mixture of several of these materials.

[0184] Preferably, the substrate is or includes metal, particularly selected from gold, stainless steel, copper and aluminum, chromium and silver.

[0185] Preferably, the substrate comprises a metal surface, particularly a gold, stainless steel, copper, aluminum, chromium, or silver surface, and more particularly a copper or gold surface. Preferably, a monolayer is applied to and in contact with the metal surface.

[0186] According to one embodiment, the substrate includes a gold surface, preferably composed of gold.

[0187] According to another embodiment, the substrate includes a copper surface, preferably composed of copper.

[0188] More preferably, the substrate comprises gold, preferably a gold surface (or is composed of gold, preferably a gold surface).

[0189] The substrate can be of any shape. It can be flat or undulating, smooth or rough, linear or curved, porous or non-porous.

[0190] Methods and uses

[0191] The present invention also relates to a method for preparing a monolayer (preferably a monolayer according to the present invention), comprising the step of applying a composition comprising at least a fluoropolymer, a silicon-sulfur compound and an ethylene polymer onto a substrate to form a thin film on the substrate.

[0192] The present invention also relates to a method for preparing an assembly comprising a substrate and a single layer as described above, comprising the step of applying a composition comprising at least a fluoropolymer, a silicon-sulfur compound and an ethylene polymer onto the substrate.

[0193] The application of the composition can be performed by any conventional coating, printing, or laminating method known to those skilled in the art. The coating method can be performed in batches or roll-to-roll (also known as roll-to-roll or R2R), roll-to-sheet, sheet-to-roll, or sheet-to-sheet processes. Preferably, the method is a roll-to-roll process, such as by roller coating or roller printing, knife coating, screen coating, dip coating, roller coating, spin coating, spray coating, gravure coating, inkjet printing, planar or rotary screen printing, slotting, photoinduced forward transfer printing (LIFT), etc.

[0194] The composition may also contain a solvent. Preferably, the method further includes the step of evaporating the solvent of the composition. Evaporation of the solvent is preferably carried out, for example, by heating and drying the film applied to the substrate at a temperature of 60 to 190°C. Drying can be performed by any method, such as, but not limited to, air drying, hot plate drying, infrared drying, laser drying, and microwave drying. Drying is preferably carried out by passing the liquid composition applied to the substrate through a drying oven, tenter frame, or drying chamber, for example, in a roll-to-roll manner. Alternatively, the film can be formed by batch drying or curing. The drying temperature varies depending on the type and content of the solvent. When a blend of solvents is used, the drying temperature and time can also be affected.

[0195] The composition can be prepared by blending, mixing or coupling fluoropolymers, silicon-sulfur compounds and ethylene polymers together, preferably by dissolving fluoropolymers, ethylene polymers and silicon-sulfur compounds in a suitable solvent.

[0196] The present invention also relates to components comprising the single layer of the present invention. Preferably, in the component, the single layer is coated on a substrate. No pretreatment such as corona pretreatment is required before coating the composition onto the substrate.

[0197] The substrate is preferably as described above.

[0198] Therefore, the component preferably includes the components described above, namely, a substrate / laminate.

[0199] In some implementations, the component has a piezoelectric function and participates in the fabrication of a piezoelectric element or device; an electronic element or device; an energy storage device or element; a semiconductor element or device; an energy generating element or device; or a dielectric element or device or a tactile element or device.

[0200] Piezoelectric and electroactive devices preferably have active or passive functions.

[0201] Examples of piezoelectric elements or devices are piezoelectric transducers, piezoelectric sensors, piezoelectric actuators, and piezoelectric energy harvesters.

[0202] Examples of electronic components or devices include capacitors, microelectromechanical systems (MEMS) components, flexible electronic devices, printed circuit boards, integrated circuits, and tactile devices.

[0203] An example of a semiconductor element or device is a light-emitting element.

[0204] Examples of energy storage elements or devices are electrodes, particularly flexible electrodes.

[0205] Examples of energy-generating elements or devices are photoelectric conversion elements, piezoelectric elements, thermoelectric conversion elements, actuators for micro / nanomachines; and solar cells.

[0206] The present invention also relates to a device including the above-described components.

[0207] In some implementations, the device is a transducer, sensor, actuator, medical device such as a pacemaker, tactile sensor for checking defects or for diagnosing / treating diseases, strain-resistant material such as building, bridge, dam, aircraft and space equipment, broadcasting equipment, wireless mobile device, mobile communication equipment, radar, high-speed information processing equipment, display device, or probe.

[0208] The present invention also relates to the use of ethylene polymers and silicon-sulfur compounds, consisting of carbon and hydrogen atoms and optionally oxygen and / or nitrogen atoms, in improving the adhesion strength of fluoropolymers on a substrate, preferably on a metal surface of the substrate.

[0209] The present invention also relates to a method for improving the adhesive strength of a fluoropolymer on a substrate by adding an ethylene polymer and a silicon-sulfur compound to a composition comprising a fluoropolymer and applying the composition to a substrate, wherein the ethylene polymer consists of carbon and hydrogen atoms and optionally oxygen and / or nitrogen atoms.

[0210] In particular, the adhesive strength of fluoropolymers in aqueous solutions is improved. Specifically, the adhesive strength of fluoropolymers is improved when they come into contact with water, moisture, sweat, saliva, or any kind of bodily fluid.

[0211] Fluoropolymers, vinyl polymers, silicon sulfides, and substrates are as described above according to any embodiment.

[0212] The present invention also relates to the use of the single layer of the present invention as a dielectric insulating layer.

[0213] The present invention also relates to the use of the single layer of the present invention as a piezoelectric layer.

[0214] The present invention also relates to the use of the monolayer of the present invention as an electroactive layer.

[0215] The present invention also relates to the use of the single layer of the present invention as a thermoelectric layer. Attached Figure Description

[0216] Figure 1 This is a circuit diagram used to measure the capacitance and loss factor of a polymer monolayer. Detailed Implementation

[0217] The following examples illustrate the present invention, but do not limit the invention.

[0218] Example

[0219] Several monolayers with different compositions were prepared on a laboratory scale according to the following protocol (each step was performed at room temperature):

[0220] 1 / Weigh the solvent in the vial;

[0221] 2 / Weigh the fluoropolymer in the same vial, stir the mixture for 30 minutes, and then let it stand for 1 hour;

[0222] 3 / Weigh the silicon-sulfur compound and ethylene polymer and add them to the vial. Then, stir the mixture for 10 minutes, and then let it stand until all bubbles disappear. The total content of the "active ingredients" (fluoropolymer, silicon-sulfur compound, and ethylene polymer) is 15% by mass.

[0223] Each composition is then applied to a metal substrate by screen printing, and the solvent is evaporated by heating.

[0224] Use transparent tape to assess the adhesion of each layer according to the following method:

[0225] Tape type: 3M 2525

[0226] Bond strength of steel: 75 N / 100 mm

[0227] step:

[0228] 1 / Cut a piece of adhesive about 3 cm long and fold one end over.

[0229] 2 / Apply adhesive to the sample by applying controlled and uniform pressure (finger pressure) to the sample surface.

[0230] 3 / Use medium, constant force (by hand) to peel off the adhesive at a 180° angle.

[0231] 4 / Visually inspect the test area on the sample to identify any delamination of the film on the substrate.

[0232] Scoring criteria:

[0233] 5: No delamination; all layers on the substrate remain intact.

[0234] 4: In the area where the tape is applied, less than 5% (surface area) of the layer is delaminated.

[0235] 3: In the area where the tape is applied, 5% to 15% (surface) of the layer is delaminated.

[0236] 2: In the area where the tape is applied, 15% to 35% (surface) of the layer should be delaminated.

[0237] 1: In the area where the tape is applied, 35% to 65% (surface) of the layer is delaminated.

[0238] 0: More than 65% (surface area) of the tape is delaminated in the application area.

[0239] The horizontal adhesive strength of each monolayer after immersion in the aqueous solution was also evaluated according to the following scheme:

[0240] Soaking delay: 3 days, 7 days, 10 days, 14 days

[0241] step:

[0242] 1 / Prepare an aqueous bath

[0243] 2 / Immerse each sample completely in the aqueous solution, carefully avoiding contact with or friction on the layer (this may damage it).

[0244] 3 / Close the container to prevent the aqueous solution from evaporating.

[0245] 4 / Take samples after soaking for x days.

[0246] 5. Carefully wipe away any remaining aqueous solution from the layer with a lint-free cloth, ensuring the layer remains, and allow it to dry.

[0247] 6 / Perform a peel test using the above steps and standards.

[0248] The table below compiles detailed information on each layer composition and the test results for each layer, where the ethylene polymer content and adhesive accelerator content are calculated relative to the weight of the fluoropolymer:

[0249]

[0250]

[0251] *:Compare

[0252] MPTMS:

[0253]

[0254] MPMDMS:

[0255]

[0256] Pentaerythritol tetra(3-mercaptopropionate):

[0257]

[0258] These results indicate that even after immersion in aqueous solution for 14 days, the presence of adhesion promoters and vinyl polymers is necessary to obtain fluoropolymer layers exhibiting high adhesion properties.

[0259] These results also indicate that even after immersion in aqueous solution for 14 days, sulfur-containing compounds without any silicon cannot effectively produce fluoropolymer layers exhibiting high adhesive properties.

[0260] The dielectric properties of the adhesion-improving layer were compared with those of a single-layer fluoropolymer. Test samples were prepared according to the following protocol:

[0261] 1. Coat the polymer layer onto the metal foil and cure it as described above.

[0262] 2. Place a mask containing several circular holes over the polymer film.

[0263] 3. The stack is placed inside a metallization apparatus, whereby vapor-deposited gold can be applied onto a thin film not covered by the mask to create conductive pads of a predetermined surface area.

[0264] 4. Then, the actual surface area of ​​each pad is measured using a microscope.

[0265] 5. The capacitance C and loss factor tanδ of each pad were measured at different frequencies (1, 10, 50, and 100 kHz) using a GWIntek LCR-819 instrument (see [reference]). Figure 1 ).

[0266] The dielectric constant ε represents a material's tendency to store electrical energy in an electric field. It essentially defines how a material responds to an electric field and describes the polarizability of a dielectric material: materials with high dielectric constants respond to an applied electric field with greater polarization than materials with low dielectric constants, thus storing more energy within the material. It is a fundamental property of electromagnetism and plays a crucial role in the design of capacitors, insulators, and other electronic devices.

[0267] The loss factor tanδ quantifies the energy loss of a dielectric material under an alternating electric field. It represents the dissipative effects within the material, such as energy loss caused by dielectric conductivity and dipole orientation.

[0268] Relative permittivity ε r Calculate using the following formula:

[0269]

[0270] Where C = capacitance, t = film thickness, and A s = Pad surface area, ε0 = Vacuum permittivity.

[0271] Each measurement was repeated 15 to 18 times, and the average values ​​of the dielectric constant and loss factor were calculated. The results are summarized in the table below, showing the average values:

[0272]

[0273]

[0274] These results demonstrate that all these layers exhibit remarkably identical dielectric properties, regardless of whether they consist solely of fluoropolymers, a mixture of fluoropolymers and silicon-sulfur compounds, or a mixture of fluoropolymers, silicon-sulfur compounds, and vinyl compounds. Surprisingly, the presence of silicon-sulfur compounds and vinyl compounds does not alter the dielectric properties of the fluoropolymers, even though they themselves possess no dielectric properties.

[0275] These results indicate that the adhesion promoter not only provides better adhesion and avoids delamination after immersion in water, but also limits the decrease in dielectric constant.

[0276] Therefore, this single layer can withstand humidity, water immersion or other liquid contact, and can still perform responses in electronic applications such as actuators (devices that convert electrical energy into mechanical motion), sensors (devices that detect changes in the environment and convert them into electrical signals), or energy storage devices (electrodes and membranes in batteries and supercapacitors).

Claims

1. A single layer, which includes: - Fluoropolymers, -Silicon-sulfur compounds, and - Ethylene polymers, which consist of carbon and hydrogen atoms, and optionally oxygen and / or nitrogen atoms.

2. The monolayer according to claim 1, wherein the fluoropolymer comprises units of a fluoropolymer derived from formula (I): C(X1)(X2)=C(X3)(X4)(I), X1, X2, X3 and X4 are each independently selected from H, Cl, Br, F, I and C1-C6 straight-chain or branched alkyl groups, wherein the C1-C6 straight-chain or branched alkyl groups are optionally partially or completely halogenated, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

3. The monolayer according to claim 1, wherein the fluoropolymer is a terpolymer of vinylidene fluoride, a second fluorinated monomer, and a third fluorinated monomer, provided that the second fluorinated monomer and the third fluorinated monomer are different from vinylidene fluoride and are distinct from each other, and wherein the second fluorinated monomer and the third fluorinated monomer are as shown in formula (I): C(X1)(X2)=C(X3)(X4)(I), X1, X2, X3 and X4 are each independently selected from H, Cl, Br, F, I and C1-C6 straight-chain or branched alkyl groups, which are optionally partially or completely halogenated, provided that at least one of X1, X2, X3 and X4 contains at least one fluorine atom.

4. The monolayer according to claim 1, wherein the content of the fluoropolymer is from 80% to 99.9% by mass relative to the total mass of the monolayer.

5. The monolayer according to claim 1, wherein the silicon-sulfur compound is as shown in formula (II): (Rd)S–Rw–Si(Ra)(Rb)(Rc)(II), Rw is a straight-chain, branched, or cyclic group comprising 1 to 18 carbon atoms and optionally one or more oxygen atoms and / or nitrogen atoms, Ra, Rb, and Rc are each independently selected from: H, OH, Alk, and -O-Alk, Alk being a C1-C8 straight-chain or branched alkyl group, and Rd is selected from: H and an organic moiety comprising 1 to 30 carbon atoms, at least one nitrogen atom, and / or at least one oxygen atom.

6. The monolayer according to claim 1, wherein the content of the silicon-sulfur compound is from 0.05% by mass to 10% by mass relative to the total mass of the monolayer.

7. The monolayer according to claim 1, wherein the vinyl polymer comprises vinyl units derived from the formula C(X)(X')=C(X”)(X”'), wherein X, X', X” and X”' are independently selected from: hydrogen atoms, OH groups, COOH groups, CN groups, aryl groups, and saturated or unsaturated hydrocarbon groups comprising 1 to 10 carbon atoms, wherein the aryl or hydrocarbon groups optionally further comprise OH groups, ester groups, carboxyl groups, amino groups, nitrile groups and / or amide groups.

8. The monolayer according to claim 1, wherein the ethylene polymer is an acrylate polymer comprising units of an acrylate monomer derived from formula (III): Xa and Xb are independently selected from: H, -CN groups, and C1-C8 straight-chain, branched, or cyclic saturated or unsaturated groups containing 1 to 8 carbon atoms, and Xc is selected from: H, benzyl, and straight-chain, branched, or cyclic saturated or unsaturated aliphatic or aromatic groups containing 1 to 24 carbon atoms, wherein the aliphatic or aromatic groups are optionally substituted by at least one OH group and / or one COOH group, and / or optionally interrupted by at least one -O- atom.

9. The monolayer according to claim 1, wherein the content of the ethylene polymer is from 0.05% by mass to 10% by mass relative to the total mass of the monolayer.

10. The single layer according to claim 1, wherein the thickness is 0.1-50 μm.

11. The monolayer according to claim 1, wherein the total mass of the fluoropolymer, the silicon-sulfur compound, and the ethylene polymer in the monolayer exceeds 80% by mass relative to the total mass of the monolayer.

12. An assembly comprising a substrate and a monolayer according to any one of claims 1 to 11, said monolayer being applied to and in contact with at least one surface of said substrate, or being applied to a portion of the surface of said substrate.

13. The component of claim 12, wherein the substrate comprises a metal surface, and the monolayer is applied to and in contact with the metal surface.

14. The component of claim 12, wherein the substrate comprises a gold surface.

15. The component of claim 12, wherein the substrate comprises a copper surface.

16. A method for preparing a monolayer according to any one of claims 1 to 11, comprising the step of applying a composition comprising at least a fluoropolymer, a silicon-sulfur compound, and an ethylene polymer onto a substrate.

17. A component comprising a single layer coated on a substrate according to any one of claims 1 to 11.

18. An apparatus comprising the component of claim 17.

19. Use of ethylene polymers consisting of carbon and hydrogen atoms, and optionally oxygen and / or nitrogen atoms, and silicon-sulfur compounds in improving the adhesive strength of fluoropolymers on substrates.

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