Fluoroelastomer composition with high heat rating

Abstract

This invention relates to fluoroelastomer compositions comprising: one or more fluoroelastomers (A) comprising 40% to 69% of repeating units derived from tetrafluoroethylene (TFE), 30% to 59% (molar) of repeating units derived from one or more perfluoroalkyl vinyl ethers (PAVE), and less than 1.5% (molar) of repeating units derived from a monomer (CS-N) having at least a nitrile group and containing a curing site; and one or more curing agents (B) comprising cationic and anionic compounds having the following formula: A n q‑ Q p n+ Where m, n, p, and q are positive integers, where mp = nq, where Qn+ is a cation, and A q‑ It is an anion according to formula (I), wherein each R is independently H, halogen, alkyl, aryl, aralkyl, or cycloalkyl, and may also be halogenated, fluorinated, or perfluorinated, wherein two or more of the R and R' groups may form a ring together, wherein each R group may independently contain one or more heteroatoms, wherein R' may be the same as R, provided that R' is not a halogen. The compositions of the present invention are capable of providing cured parts with the ability to maintain excellent sealing performance at very high temperatures. The present invention also relates to a method of curing the composition and cured articles obtained from the composition, which can be used as sealing parts in the semiconductor industry. (I).

Description

Technical Field

[0001] This invention relates to: a fluoroelastomer composition capable of providing cured parts with the ability to maintain excellent sealing performance at very high temperatures; a method for curing the fluoroelastomer composition; and cured articles obtained from the fluoroelastomer composition, which are particularly suitable for use as sealing parts in the semiconductor industry. This application claims priority to European Patent Application 24171158.9, filed April 18, 2024, the entire contents of which are incorporated herein by reference for all purposes. Background Technology

[0002] Fluoroelastics, and more specifically tetrafluoroethylene-based fluoroelastics, have long been used in a variety of applications requiring excellent resistance to several harsh conditions, including high temperatures, chemical corrosion, and exposure to plasma, particularly in the semiconductor manufacturing industry. Especially in this field, the possibility of providing cured parts capable of withstanding temperatures up to 320°C–330°C and up to approximately 350°C, while also possessing all the other advantageous properties of perfluororubber, has been a long-standing need in this sector.

[0003] Many curing agents are commercially available and described in the literature. US7402630 from 3M describes a curing agent comprising cationic and anionic compounds, having the following formula:

[0004] A n q- Q p n+

[0005] Where m, n, p, and q are positive integers, and m p = n q, where Qn+ is an organonium ion, and Aq- is an anion according to the following formula:

[0006]

[0007] Each R is independently H, halogen, alkyl, aryl, aralkyl, or cycloalkyl, and may also be halogenated, fluorinated, or perfluorinated, wherein two or more of the R and R' groups may form a ring together, wherein each R group may independently contain one or more heteroatoms, wherein R' may be the same as R, provided that R' is not halogenated.

[0008] These curing agents are described as effectively curing fluoroelastomer compositions and effectively providing satisfactory sealing properties to the resulting fluoroelastomers at high temperatures.

[0009] However, materials that exhibit even higher performance at high temperatures are needed to be used as sealing elements in a wider range of applications.

[0010] The applicant has unexpectedly discovered that combining these curing agents with selected fluoroelastomers of PAVE comonomers with carefully controlled levels and nitrile-containing curing site monomers with carefully controlled levels produces cured fluoroelastomers with excellent heat resistance properties. Summary of the Invention

[0011] This invention relates to a fluoroelastomer composition comprising: A: one or more fluoroelastomers (A), wherein the one or more fluoroelastomers comprise:

[0012] - Repeating units derived from tetrafluoroethylene (TFE), wherein the amount of these repeating units is 40% to 69%, preferably 49% to 65%, relative to the total molar number of repeating units of the fluoroelastomer (A) on a molar basis;

[0013] - Derived from one or more formulas having CF2=CFOR f The repeating unit of perfluoroalkyl vinyl ether (PAVE), wherein R f It is a C1-C6 perfluoroalkyl group, and the amount of these repeating units is 30% to 59% (more preferably 34% to 50%) of the total molar number of repeating units of the fluoroelastomer (A) relative to the total number of repeating units.

[0014] - Repeating units derived from monomers (CS-N) having at least nitrile groups containing curing sites, wherein the amount of these repeating units is less than 1.5% by molar, preferably 0.1% to 1.4% by molar, more preferably 0.5% to 1.3% by molar, and most preferably between 1% and 1.3% by molar, relative to the total molar number of repeating units of the fluoroelastomer (A).

[0015] as well as

[0016] B: One or more curing agents (B) comprising cationic and anionic compounds, having the following formula:

[0017] A n q- Q p n+

[0018] Where m, n, p, and q are positive integers, and m p = n q, where Q n+ It is a cation, and A q- It is based on the following formula for anions:

[0019]

[0020] Each R is independently H, halogen, alkyl, aryl, aralkyl, or cycloalkyl, and may also be halogenated, fluorinated, or perfluorinated, wherein two or more of the R and R' groups may form a ring together, wherein each R group may independently contain one or more heteroatoms, wherein R' may be the same as R, provided that R' is not halogenated. Detailed Implementation

[0021] For the purposes of this invention, the term "(per)fluorinated elastomer" is intended to refer to a fluoropolymer resin used as a base component for obtaining a true elastomer, the fluoropolymer resin comprising repeating units derived from at least one olefinically unsaturated monomer containing at least one fluorine atom (hereinafter, (per)fluorinated monomer), and optionally, repeating units derived from at least one olefinically unsaturated monomer without fluorine atoms (hereinafter, hydrogenated monomer).

[0022] A true elastomer is defined by ASTM, Special Technical Bulletin, 184 as a material that can be stretched to twice its intrinsic length at room temperature and, after being held under tension for 5 minutes, recovers to no more than 10% of its initial length within the same time after being released.

[0023] The present invention relates to a fluoroelastomer composition comprising a selected fluoroelastomer (A) and a selected curing agent (B).

[0024] The fluoroelastomer (A) used in this invention comprises:

[0025] - Repeating units derived from tetrafluoroethylene (TFE), wherein the amount of these repeating units is 40% to 69% by molar relative to the total number of repeating units of the fluoroelastomer (A);

[0026] - Derived from one or more formulas having CF2=CFOR f The repeating unit of perfluoroalkyl vinyl ether (PAVE), wherein R f It is a C1-C6 perfluoroalkyl group, and the amount of these repeating units is 30% to 59% (more preferably 34% to 50%) of the total molar number of repeating units of the fluoroelastomer (A) relative to the total number of repeating units.

[0027] - Repeating units derived from monomers (CS-N) having at least nitrile groups containing curing sites, wherein the amount of these repeating units is less than 1.5% by molar, preferably 0.1% to 1.4% by molar, more preferably 0.5% to 1.3% by molar, and most preferably between 1% and 1.3% by molar, relative to the total molar number of repeating units of the fluoroelastomer (A).

[0028] Among the perfluoroalkyl vinyl ether (PAVE) monomers, alkyl vinyl ethers selected from perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, and mixtures thereof are preferred. More preferably, the perfluoroalkyl vinyl ether monomer is selected from perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, and mixtures thereof. Most preferably, the perfluoroalkyl vinyl ether monomer is perfluoromethyl vinyl ether.

[0029] Among the (CS-N) type monomers containing curing sites included in the fluoroelastomer (A) as detailed above, preferred monomers are fluorinated, more preferably perfluorinated, and especially those selected from the group consisting of:

[0030] (CS-N1) has the formula CF2=CF-[OCF2CFX] CN (CF2) a1 ] m -O-(CF2) n -CN perfluorovinyl ethers containing nitrile groups, wherein X CN It is F or CF3, a1 is 0, 1 or 2; m is 0, 1, 2, 3 or 4; n is an integer from 1 to 12;

[0031] (CS-N2) has the formula CF2=CF-(OCF2CFX) CN (CF2) a2 ) m' -O-CF2—CF(CF3)-CN is a perfluorovinyl ether containing a nitrile group, wherein X CN It is F or CF3, a2 is 0, 1 or 2; m' is 0, 1, 2, 3 or 4.

[0032] Specific examples of monomers of the CS-N1 and CS-N2 types containing curing sites suitable for the purposes of this invention are particularly those described in patents US 4281092 (DuPont) 28 / 07 / 1981, US 4281092 (DuPont) 28 / 07 / 1981, US 5447993 (DuPont) 5 / 09 / 1995, and US 5789489 (DuPont) 4 / 08 / 1998.

[0033] The most preferred monomer for curing sites (CS-N) is, in particular, a perfluorinated (8-cyano-5-methyl-3,6-dioxa-1-octene) having the following formula: CF2=CF-O-CF2-CF(CF3)-O-CF2-CF2-CN (8-CNVE) and monomers having the formula CF2=CF-O-CF2-CF2-CF2-O-CF2-CF(CF3)-CN. Most preferably, the monomer (CS-N) is 8-CNVE as described above. When increased chemical resistance is required, monomers having the formula CF2=CF-O-CF2-CF2-CF2-O-CF2-CF(CF3)-CN may be most preferred.

[0034] In addition to repeating units derived from tetrafluoroethylene, repeating units derived from PAVE monomers, and repeating units derived from (CS-N) monomers, the fluoroelastomer (A) may also contain repeating units derived from one or more other (per)fluorinated monomers. Such one or more other perfluorinated monomers may preferably be selected from the group consisting of:

[0035] (a) C3-C8 perfluoroolefins, such as hexafluoropropylene (HFP);

[0036] (b) A C2-C8 fluoroolefin containing at least one of iodine, chlorine and bromine, such as trifluorochloroethylene (CTFE).

[0037] (c) C2-C8 hydrofluoroolefins, such as fluoroethylene; 1,2-difluoroethylene, vinylidene fluoride (VDF), trifluoroethylene (TrFE), pentafluoropropylene and hexafluoroisobutylene;

[0038] (d) Conforms to the formula CH2=CH-R f0 (Per)fluoroalkyl ethylene, wherein R f0 It is a C1-C6 (per)fluoroalkyl or a C1-C6 (per)fluorooxyalkyl having one or more ether groups;

[0039] (e) (per)fluoroalkyl vinyl ethers having the formula CF2=CFOX, wherein X is a C-type carbon containing chain oxygen atoms. 1- C 12 (Per)fluoroalkyl groups, such as perfluoro-2-propoxypropyl; among these monomers, (e') perfluoromethoxy vinyl ethers (MOVE, hereinafter) having the following formula are preferred:

[0040] CF2=CFOCF2OR f2

[0041] Where R f2 Select from the following groups: C1-C6 (per)fluoroalkyl; C 5-C6 cyclic (per)fluoroalkyl groups; and C2-C6 (per)fluoroalkyl groups containing at least one chain oxygen atom; R f2 Preferably, it is -CF2CF3(MOVE1); -CF2CF2OCF3(MOVE2); or -CF3(MOVE3);

[0042] (f) Perfluorom-dioxanes having the following formula:

[0043]

[0044] Where R f3 R f4 R f5 R f6 Each of them may be the same as or different from each other, and is independently selected from the group consisting of: fluorine atoms and C1-C6 (per)fluoroalkyl groups that optionally contain one or more oxygen atoms, such as especially -CF3, -C2F5, -C3F7, -OCF3, -OCF2CF2OCF3; preferably, perfluorodioxane.

[0045] More preferably, such one or more additional perfluorinated monomers are selected from the group consisting of:

[0046] (a1) Hexafluoropropylene (HFP);

[0047] (e1) Perfluoroalkyl vinyl ethers having the formula CF2=CFOX, wherein X is a C1-C bond containing a chain of oxygen atoms. 12 Perfluoroalkyl; and more preferably (e'1) perfluoromethoxy vinyl ethers having the following formula (MOVE, hereinafter): CF2=CFOCF2OR 1 f2 , where R 1 f2 Selected from the group consisting of: C1-C3 perfluoroalkyl groups; and C2-C6 perfluorooxyalkyl groups containing at least one chain oxygen atom; R 1 f2 Preferably selected from -CF2CF3; -CF2CF2OCF3; or -CF3.

[0048] Fluoroelastics (A) may also contain repeating units derived from fluorine-free monomers, which will be referred to below as hydrogenated monomers. Examples of hydrogenated monomers are, in particular, hydrogenated α-olefins, including ethylene, propylene, 1-butene, diene monomers, and styrene monomers, with α-olefins being used typically.

[0049] The fluoroelastomer (A) of the present invention may further comprise repeating units derived from diene [diene (OF)] having the following general formula:

[0050]

[0051] R1, R2, R3, R4, R5, and R6 may be the same as or different from each other, and are independently selected from the following groups: F, Cl, H, C1-C5 (fluoro)alkyl groups and -OR groups. B , where R B It is a branched or straight-chain alkyl group that can be partially, substantially, or completely fluorinated or chlorinated; Z is a straight-chain or branched C1-C group that optionally contains an oxygen atom, preferably at least partially fluorinated. 18 (Hydrogen) carbon groups (including alkylene or cycloalkylene groups), or (per)fluoro(poly)oxyalkylene groups containing one or more chain-like ether bonds.

[0052] Dienes (OF), if present, are preferably selected from the group consisting of dienes conforming to formulas (OF-1), (OF-2), and (OF-3):

[0053] (OF-1)

[0054]

[0055] Where j is an integer between 2 and 10, preferably between 4 and 8, and R1, R2, R3, and R4 are either the same or different from each other, and are H, F, or C. 1-5 Alkyl or (per)fluoroalkyl;

[0056] (OF-2)

[0057]

[0058] Each A is either the same as or different from each other and is independently selected from F, Cl, and H each time it appears; each B is either the same as or different from each other and is independently selected from F, Cl, H, and OR each time it appears. B , where R B It is a branched or straight-chain alkyl group that can be partially, substantially, or completely fluorinated or chlorinated; E is an optionally fluorinated divalent group having 2 to 10 carbon atoms, which may be inserted with an ether bond; preferably E is -(CF2). m - group, where m is an integer from 3 to 5; the preferred (OF-2) type diene is F2C=CF-O-(CF2)5-O-CF=CF2.

[0059] (OF-3)

[0060]

[0061] E, A, and B have the same meaning as defined above; R5, R6, and R7 are the same as or different from each other, and are H, F, or C. 1-5 Alkyl or (per)fluoroalkyl.

[0062] If present, a more preferred diene (OF) is a diene having the formula (OF-1) as detailed above, and most preferably it is divinylperfluorohexane.

[0063] For embodiments in which the fluoroelastomer (A) comprises repeating units derived from the bis-olefin (OF) as detailed above, the amount of the bis-olefin (OF) is typically at least 0.04 mol%, preferably at least 0.05 mol%, and / or at most 0.25 mol%, preferably at most 0.20 mol%, relative to the total number of moles of the repeating units of the fluoroelastomer (A).

[0064] As is known to those skilled in the art, the introduction of diene repeating units into fluoroelastomer A increases the branching level of fluoroelastomer A. For the purposes of this invention, fluoroelastomer (A) is preferably selected from linear fluoroelastomers or fluoroelastomers with a low level of branching, and therefore fluoroelastomer A preferably does not contain repeating units derived from dienes.

[0065] Exemplary preferred fluoroelastomers (A) that can be used in the compositions of the present invention are those having the following monomer compositions (in mol% relative to the total number of moles of repeating units):

[0066] Tetrafluoroethylene (TFE): 40%-69%; (per)fluoroalkyl vinyl ether (PAVE): 30%-59%; Monomer (CS-N).

[0067] Fluoroelastics (A) are generally amorphous products or have low crystallinity (less than 20% crystalline phase by volume) and a glass transition temperature (T0) below room temperature. g The product of fluoroelastomer (A). In most cases, the fluoroelastomer (A) advantageously has a temperature T below 10°C, preferably below 5°C, more preferably 0°C. g .

[0068] In the exemplary preferred fluoroelastomer (A), there may also be end chains, defects, or small amounts of monomeric impurities that cause the repeating units to differ from those mentioned above (typically < 0.1 mol% relative to the total amount of repeating units), which do not affect the properties of the material.

[0069] The compositions of the present invention further comprise one or more curing agents (B). Curing agent B comprises a cation and an anion, having the following formula:

[0070] A n q- Q p n+

[0071] Where m, n, p, and q are positive integers, and m p = n q, where Q n+ It is a cation, and A q- It is based on the following formula for anions:

[0072]

[0073] Each R is independently H, halogen, alkyl, aryl, aralkyl, or cycloalkyl, and may also be halogenated, fluorinated, or perfluorinated, wherein two or more of the R and R' groups may form a ring together, wherein each R group may independently contain one or more heteroatoms, wherein R' may be the same as R, provided that R' is not halogenated.

[0074] For example, each R can be F, such that the central carbon of the anion is bonded to two perfluoromethyl groups. Furthermore, R' can be selected from the group consisting of: H, phenyl, methoxyphenyl, tolueneyl, phenoxy, fluorophenyl, trifluoromethylphenyl, and CF3. Preferably, each R is F and R' is a substituted or unsubstituted aromatic ring, more preferably R' is an aromatic ring substituted with one or more C1-C3 alkyl groups, and even more preferably R' is an aromatic ring substituted with one, two, or three -CF3 groups.

[0075] Cation Q n+ There are no particular restrictions on the choice of cation, and metal ions can be used, although the cation is preferably selected from ammonium, phosphorus and organonium ions, and more preferably organonium ions.

[0076] Preferred organonium ions are monoalkylammonium ions, dialkylammonium ions, trialkylammonium ions, and tetraalkylammonium ions, as well as monoalkylphosphonium ions, dialkylphosphonium ions, trialkylphosphonium ions, and tetraalkylphosphonium ions. More preferred cations are tetraalkylammonium and tetraalkylphosphonium, and most preferred cations are tetrabutylammonium and tetrabutylphosphonium.

[0077] Examples of curing agent B include 2-phenyl-1,1,1,3,3-hexafluoroisopropanol tetraalkylammonium, 1,1,1,3,3-hexafluoroisopropanol tetraalkylammonium, 2-phenyl-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, 1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, 2-methoxyphenyl-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, and 2-p-toluamide-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium.

[0078] The preferred curing agent B is 2-p-toluamide-1,1,1,3,3,3-hexafluoroisopropoxide.

[0079] The curing agent (B) is an agent capable of promoting the crosslinking of the fluoroelastomer (A) by reacting with the curing sites of the monomer (CS-N). This curing agent can be introduced into the composition of the present invention in pure form or preferably loaded on an inert support (such as a SiO2 support).

[0080] One or more curing agents (B) may be used in the compositions of the present invention.

[0081] The fluoroelastomer compositions of the present invention may further comprise components that are typically used in curable compositions, such as:

[0082] (a) One or more basic metal compounds, in an amount of 0.5 to 15 phr, and preferably 1 to 10 phr, relative to 100 parts by weight of fluoroelastomer (A); the basic metal compounds are generally selected from the group consisting of: (i) oxides or hydroxides of divalent metals, such as oxides or hydroxides of Mg, Zn, Ca or Pb, and (ii) metal salts of weak acids, such as stearates, benzoates, carbonates, oxalates or phosphites of Ba, Na, K, Pb, Ca;

[0083] (b) One or more acid acceptors that are not metal basic compounds, in an amount of generally 0.5 to 15 phr, and preferably 1 to 10 phr, relative to 100 parts by weight of fluoroelastomer (A); these acid acceptors are generally selected from nitrogen-containing organic compounds, such as 1,8-bis(dimethylamino)naphthalene, octadecylamine, etc., as particularly described in EP 708797 A (DuPont) 1 / 05 / 1996;

[0084] (c) Other conventional additives, such as fillers, thickeners, pigments, antioxidants, stabilizers, processing aids, etc.

[0085] In the filler, fluorinated reinforced fillers, particularly those of nanoscale size, composed of fluoroplastics, can be advantageously used. Therefore, according to certain embodiments, the compositions of the present invention may comprise at least one semi-crystalline fluoropolymer in an amount generally 10 to 70 parts by weight, preferably 12 to 60 parts by weight, relative to 100 parts by weight of the fluoroelastomer (A); said semi-crystalline fluoropolymer is generally selected from the group consisting of: tetrafluoroethylene (TFE) homopolymers and copolymers of TFE with one or more monomers containing at least one ethylene-type unsaturation, wherein the amount of said monomer is 0.01 to 10 mol%, and preferably 0.05 to 7 mol%. Within this framework, it is particularly preferred to include a filler derived from at least one having the formula CF2=CFOR. f (per)fluoroalkyl vinyl ethers (PAVE) (wherein R fIt is a semi-crystalline TFE copolymer of repeating units of C1-C6 (per)fluoroalkyl, preferably CF3, C2F5, C3F7. From a morphological point of view, for these embodiments, the preferred semi-crystalline fluoropolymers are those having an average particle size between 10 and 400 nm, preferably 10 to 250 nm, and even more preferably 10 to 100 nm.

[0086] The present invention also relates to a method for manufacturing molded articles, the method comprising curing the fluoroelastomer composition of the present invention.

[0087] The fluoroelastomer compositions of the present invention can be used to manufacture molded articles by conventional techniques, such as molding (injection molding, extrusion molding), calendering or extrusion into desired molded articles, advantageously subjecting the molded articles to vulcanization (curing) during their own processing and / or in subsequent steps (post-treatment or post-curing); advantageously transforming relatively soft, weak, uncured fluoroelastomer compositions into finished products made of non-sticky, strong, insoluble, chemically and heat-resistant cured fluoroelastomer materials.

[0088] The present invention also relates to cured articles obtained from the fluoroelastomer compositions of the present invention. These cured articles are typically obtained by molding and curing the fluoroelastomer compositions detailed above. These cured articles can be, for example, sealing articles including O-rings (square rings), fillers, gaskets, door sleeves, diaphragms, shaft seals, valve stem seals, piston rings, crankshaft seals, camshaft seals, and oil seals, or can be pipes and tubing, particularly sealing parts or other articles included in semiconductor manufacturing equipment.

[0089] Furthermore, the present invention also relates to a method for processing the fluoroelastomer composition of the present invention according to any one of injection molding, compression molding, extrusion molding, coating, screen printing technology, and in-situ forming technology.

[0090] If any patent, patent application, or disclosure incorporated herein by reference conflicts with this description to the extent that it may lead to ambiguity in terminology, this description shall take precedence.

[0091] The invention will now be described in more detail with reference to the following examples, which are for illustrative purposes only and do not limit the scope of the invention.

[0092] raw material

[0093] Curing agent B: 2-p-toluyl-I-1,1,3,3-tetrabutylphosphonium hexafluoroisopropionate, 34 wt% on SiO2 support, supplied by 3M.

[0094] Comparison curing agent: Bisaminophenol AF (BOAP, hereinafter) was supplied by Apollo Scientific and used as is.

[0095] Fluoroelastomer A1: TFE 64.7 mol%, MVE 34.3 mol%, 8-CNVE 1.1 mol%, and Mooney viscosity at 121°C is 101 MU.

[0096] Fluoroelastomer A2: TFE 61.7 mol%, MVE 37.1 mol%, 8-CNVE 1.2 mol%, and Mooney viscosity at 121°C is 60 MU.

[0097] Fluoroelastomer A3 (comparison): TFE 65.1 mol%, MVE 33.1 mol%, CN 1.8 mol%, and Mooney viscosity at 121°C is 60 MU.

[0098] These fluoroelastomers were supplied by Solvay Specialty Polymers.

[0099] Compression deformation value measurement

[0100] Compression set (CS) is the amount of permanent deformation (as a percentage of original size) that occurs when a material is compressed to a specific deformation over a specified time at a specific temperature. A lower CS value indicates a better ability of the material to maintain a sealing pressure over time, thus preventing leaks, product failure, and hazards. Compression set (CS) values ​​have been determined for O-rings (class #214) obtained from preformed extruded cord according to ASTM D 395-B at temperatures ranging from 200°C to 325°C; the values ​​in the table are the average of measurements taken from four samples. A “fracture” rating indicates that all samples have experienced critical failure and are not suitable for determining residual deformation.

[0101] Example

[0102] Example 1.

[0103] A fluoroelastomer composition was formed by blending fluoroelastomer A1 with 20 phr of carbon black Cancarb N 990 MT and 2.25 phr of curing agent B in a two-roll open mill. The O-rings were cured in a pressing mold (15 min at 188°C) and then post-treated in an air-circulating oven (16 h at 250°C).

[0104] After storing the O-rings at different temperatures for 70 hours, CS measurements were performed. The results are shown in the table below.

[0105] Example 2

[0106] Following the same procedure as in Example 1, use fluoroelastomer A2 instead of fluoroelastomer A1.

[0107] Example C3 (Comparison)

[0108] Following the same procedure as in Example 1, use fluoroelastomer A3 instead of fluoroelastomer A1.

[0109] Example C4 (Comparison)

[0110] Following the same procedure as in Example 1, use 1 phr of BOAP instead of 2.25 phr of hardener B as the hardener.

[0111] Example C5 (Comparison)

[0112] Following the same procedure as in Example 2, use 1 phr of BOAP instead of 2.25 phr of curing agent B as the curing agent.

[0113] Table 1

[0114]

[0115] Compressive deformation was measured after a 30-minute relaxation time with a 25% deflection.

Claims

1. A fluoroelastomer composition comprising: A: One or more fluoroelastomers (A), the one or more fluoroelastomers comprising: - Repeating units derived from tetrafluoroethylene (TFE), wherein the amount of these repeating units is 40% to 69%, preferably 49% to 65%, relative to the total molar number of repeating units of the fluoroelastomer (A) on a molar basis; - Derived from one or more formulas having CF2=CFOR f The repeating unit of perfluoroalkyl vinyl ether (PAVE), wherein R f It is a C1-C6 perfluoroalkyl group, and the amount of these repeating units is 30% to 59% (more preferably 34% to 50%) of the total molar number of repeating units of the fluoroelastomer (A) relative to the total number of repeating units. - Repeating units derived from monomers (CS-N) having at least nitrile groups containing curing sites, wherein the amount of these repeating units is less than 1.5% by molar, preferably 0.1% to 1.4% by molar, more preferably 0.5% to 1.3% by molar, and most preferably between 1% and 1.3% by molar, relative to the total molar number of repeating units of the fluoroelastomer (A). as well as B: One or more curing agents (B) comprising cationic and anionic compounds, having the following formula: A n q- Q p n+ Where m, n, p, and q are positive integers, where m p = n q, where Q n+ It is a cation, and A q- It is based on the following formula for anions: Each R is independently H, halogen, alkyl, aryl, aralkyl, or cycloalkyl, and may also be halogenated, fluorinated, or perfluorinated, wherein two or more of the R and R' groups may form a ring together, wherein each R group may independently contain one or more heteroatoms, wherein R' may be the same as R, provided that R' is not halogenated.

2. The fluoroelastomer composition according to claim 1, wherein, The one or more perfluoroalkyl vinyl ether (PAVE) monomers are selected from perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether and mixtures thereof.

3. The fluoroelastomer composition according to claim 2, wherein, The one or more perfluoroalkyl vinyl ether (PAVE) monomers are perfluoromethyl vinyl ethers.

4. The fluoroelastomer composition according to claim 1, wherein, The monomer (CS-N) having at least a nitrile group and containing a curing site is selected from the group consisting of: - (CS-N1) has the formula CF2=CF-[OCF2CFX CN (CF2) a1 ] m -O-(CF2) n -CN perfluorovinyl ethers containing nitrile groups, wherein X CN It is F or CF3, a1 is 0, 1 or 2; m is 0, 1, 2, 3 or 4; n is an integer from 1 to 12; - (CS-N2) has the formula CF2=CF-(OCF2CFX) CN (CF2) a2 ) m' -O-CF2—CF(CF3)-CN is a perfluorovinyl ether containing a nitrile group, wherein X CN It is F or CF3, a2 is 0, 1 or 2; m' is 0, 1, 2, 3 or 4.

5. The fluoroelastomer composition according to claim 1 or 2, wherein, The monomer (CS-N) having at least a nitrile group and containing a curing site is selected from the group consisting of: - CF2=CF-O-CF2-CF(CF3)-O-CF2-CF2-CN (8-CNVE), and - CF2=CF-O-CF2-CF2-CF2-O-CF2-CF(CF3)-CN, and its mixtures.

6. The fluoroelastomer composition according to any one of the preceding claims, wherein, In addition to repeating units derived from tetrafluoroethylene and repeating units derived from monomers (CS-N), the fluoroelastomer (A) also comprises repeating units derived from one or more (per)fluorinated monomers, wherein the (per)fluorinated monomers are selected from the group consisting of: (a) C3-C8 perfluoroolefins, such as hexafluoropropylene (HFP); (b) A C2-C8 fluoroolefin containing at least one of iodine, chlorine and bromine, such as trifluorochloroethylene (CTFE). (c) C2-C8 hydrofluoroolefins, such as fluoroethylene; 1,2-difluoroethylene, vinylidene fluoride (VDF), trifluoroethylene (TrFE), pentafluoropropylene and hexafluoroisobutylene; (d) Conforms to the formula CH2=CH-R f0 (Per)fluoroalkyl ethylene, wherein R f0 It is a C1-C6 (per)fluoroalkyl or a C1-C6 (per)fluorooxyalkyl having one or more ether groups; (e) (per)fluoroalkyl vinyl ethers having the formula CF2=CFOX, wherein X is a C-type carbon containing chain oxygen atoms. 1- C 12 (Per)fluoroalkyl groups, such as perfluoro-2-propoxypropyl; among these monomers, (e') perfluoromethoxy vinyl ethers (MOVE, hereinafter) having the following formula are preferred: CF2=CFOCF2OR f2 Where R f2 Select from the following groups: C1-C6 (per)fluoroalkyl; C 5- C6 cyclic (per)fluoroalkyl groups; and C2-C6 (per)fluoroalkyl groups containing at least one chain oxygen atom; R f2 Preferably, it is -CF2CF3(MOVE1); -CF2CF2OCF3(MOVE2); or -CF3(MOVE3); (f) Perfluorom-dioxanes having the following formula: Where R f3 R f4 R f5 R f6 Each of them may be the same as or different from each other, and is independently selected from the group consisting of: fluorine atoms and C1-C6 (per)fluoroalkyl groups that optionally contain one or more oxygen atoms, such as especially -CF3, -C2F5, -C3F7, -OCF3, -OCF2CF2OCF3; preferably, perfluorodioxane.

7. The fluoroelastomer composition according to any one of the preceding claims, wherein, The cation Q n+ It is selected from ammonium, phosphorus and organonium ions, and more preferably organonium ions.

8. The fluoroelastomer composition according to any one of the preceding claims, wherein, The cation Q n+ It is selected from tetraalkylammonium and tetraalkylphosphonium, preferably tetrabutylammonium and tetrabutylphosphonium.

9. The fluoroelastomer composition according to any one of the preceding claims, wherein, In the anion, each R is F and R' is a substituted or unsubstituted aromatic ring.

10. The fluoroelastomer composition according to claim 9, wherein, In the anion, R' is an aromatic ring substituted with one, two, or three C1-C3 alkyl groups, preferably an aromatic ring substituted with one, two, or three CF3 groups.

11. The fluoroelastomer composition according to any one of the preceding claims, wherein, The curing agent B is selected from 2-phenyl-1,1,1,3,3-hexafluoroisopropanol tetraalkylammonium, 1,1,1,3,3-hexafluoroisopropanol tetraalkylammonium, 2-phenyl-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, 1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, 2-methoxyphenyl-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium, and 2-p-toluamide-1,1,1,3,3,3-hexafluoroisopropanol tetrabutylphosphonium.

12. The fluoroelastomer composition according to any one of the preceding claims, wherein, The curing agent B is 2-p-toluamide-1,1,1,3,3,3-hexafluoroisopropoxide.

13. The fluoroelastomer composition according to any one of the preceding claims, wherein, The curing agent B is loaded on a carrier, preferably a SiO2 carrier.

14. A method for manufacturing a molded article, the method comprising curing the composition according to any one of claims 1 to 13.

15. A cured article obtained from a fluoroelastomer composition according to any one of claims 1 to 13, said cured article being a sealing article comprising an O-ring (square ring), a packer, a gasket, a diaphragm, a shaft seal, a valve stem seal, a piston ring, a crankshaft seal, a camshaft seal, and an oil seal, as well as tubing and pipes.

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