Copolymers comprising (PER)fluoropolyether chains, mixture comprising the same, process for manufacturing the copolymer and mixture, composition comprising the copolymer or mixture, method for lubricating surface of article, and method for counteract vibrations and / or shocks in device

Abstract

This patent application relates to copolymers containing (fully)fluoropolyether chains, characterized by increased viscosity.

Description

Technical Field

[0001] This patent application relates to copolymers containing (fully)fluoropolyether chains, characterized by increased viscosity. [Cross-reference to related patent applications]

[0002] This application claims priority to European application No. 21183081.5 filed on July 1, 2021, the entire contents of which are incorporated herein by reference for all purposes. Prior Technology

[0003] Lubrication is a crucial aspect of maintaining the normal operation of machinery. Mechanical components such as bearings, pins, shafts, gears, and joints require proper lubrication between their moving surfaces to reduce friction, prevent contamination, minimize wear, and facilitate heat dissipation. Inappropriate lubrication can lead to premature wear and component or system failure.

[0004] (Fully) fluoropolyether polymers (hereinafter referred to as "PFPE polymers") have long been known as base oils or additives in several lubricant applications.

[0005] Several PFPE polymers have been synthesized in this field. The first synthesis of an unspecified mixture of perfluorinated polyethers was reported in 1953, yielding an oily product during the photo-oligopolymerization of hexafluoropropylene. Since then, many different perfluorinated polyethers have been synthesized and described in the literature.

[0006] [US 4,500,739] [(] [With Monte Edison Company] [(] [Montedison] [)] [in the name of] [] revealed the reaction of PFPE peroxide, particularly with perfluorobutadiene (a group II fluoroolefin). Example 4 revealed the reaction with perfluorobutadiene and a large excess of perfluorinated diene, generating unsaturated side-chain groups along the macromolecular chain, allowing the reaction to proceed further in the presence of hexamethylenediamine.

[0007] [US 8,258,090 B2] [(] [Solvizole] [(] [Solvay Solexis SpA] [)] [in the name of] [)] discloses fluorinated lubricants having the following formula: (I) TO-[AB]z-[A'-B']z'-AT in T and T' series are C1-3 perfluoroalkyl or C1-6 alkyl groups. A and A-series perfluoropolyether chains, B is derived from two different olefins, at least one of which can be homopolymerized via a free radical pathway. B has the following formula: (Ia) -[(CR 1R 2-CR 3R 4) j-(CR 5R 6-CR 7R 8) j']- in The series j ranges from 1 to 5, the series j' ranges from 0 to 4, and the sum of j+j' is between 2 and 5; R1 to R8 series halogens, H, C1-6 (all) haloalkyl, C1-6 alkyl, C1-6 oxy (all) fluoroalkyl; z is greater than or equal to 2, z' is an integer, and the sum of z and z' is such that the average molecular weight of the polymers having formula (I) is in the range of 500-500,000; B' series (Ia), but at least one of R1 to R8 has a different meaning than that in B. The patent discloses block copolymers characterized by a straight backbone, in other words, without branching from groups having formula B.

[0008] Polymers obtained using PFPE polymer units have been disclosed in the art. Crosslinked fluoroelastomers are one such example. In this regard, SP Krukovsky et al. – J of Fluorine Chemistry 96 (1999) 31-33 – disclosed copolymerization of perfluoroolefins containing peroxy groups in the chain with perfluorodivinyl ethers under UV radiation and heating to provide crosslinked polymers called elastomers. This literature does not disclose any amounts of reactants, nor does it provide a method for manufacturing polymers suitable for lubricants. Summary of the Invention

[0009] Although recent research and development have focused on mono- and / or bifunctional (per)fluoropolyether (PFPE) polymers, the applicant believes there is still a need to provide neutral PFPE polymers that can be used as lubricants.

[0010] The problem faced by the applicant is to provide a new neutral PFPE polymer characterized by increased viscosity (e.g., measured by a complex viscosity of 0.1 rad / s at 25°C) while maintaining a low glass transition temperature (Tg) and remaining liquid at room temperature.

[0011] The applicant has unexpectedly discovered that neutral branched (per)fluoropolyether polymers, characterized by increased viscosity due to the increase in number average molecular weight, can be provided by a method that is easily implemented on an industrial scale.

[0012] Advantageously, this method allows for the manufacture of neutral (per)fluoropolyether polymers with high thermal stability while maintaining low glass transition temperatures and increasing viscosity index (ASTM D2270), making such polymers particularly suitable as lubricants for harsh environments, including applications requiring a wide range of operating temperatures or high heat generation.

[0013] In a first aspect, the present invention relates to a block copolymer [copolymer (P)] having two ends and comprising first and second (per)fluoropolyether chains [PFPE chains], each having two ends, wherein the ends of the block copolymer both comprise perfluorinated alkyl groups, wherein the first ends of the first and second PFPE chains comprise perfluorinated alkyl groups and the second ends of the first and second PFPE chains are bonded to each other by blocks having formula (I): (I) -[AB]- in (A) is a PFPE chain, and (B) is the part that conforms to the following formula (II): (II) in n is an integer from 1 to 3; R1 to R4 are each independently selected from the group consisting of, preferably, the following: fluorine atoms, perfluorinated straight-chain or branched alkyl groups having 1 to 6 carbon atoms, and groups having formula (III): (III) -(R 10) t[C(R 11)(R 12)-C(R 13)(R 14)(R 15)] z in R 10 series oxygen atoms, or, as needed, divalent / trivalent / tetravalent perfluorinated alkyl chains containing 1 to 24 carbon atoms with and / or containing at least one oxygen atom. t is zero or 1. z represents integers from 1 to 3. R 11 to R 15 are each independently selected from the group consisting of, preferably, the following: fluorine atoms, perfluorinated straight-chain or branched alkyl groups having 1 to 6 carbon atoms, and groups having formula (IV): -[(A^) a-(B^) v]-(C^)-T (IV) in A^ series PFPE chain, a is zero or 1, v is zero or an integer from 1 to 3. The B series contains groups of the formula -[C(R1)(R2)-C(R3)(R4)]-. Among them, R1^ to R4^ each independently have the meanings defined above for R1 to R4. C^ series PFPE chain, and T-series perfluorinated alkyl groups; in: -- The systematic distribution of A and B in equation (I) and A^ and B^ in equation (IV) is as follows. -- At least one of R1 to R4 has a group of formula (III), -- One of R11 or R12 and one of R13 to R15 have a group of formula (IV), wherein a is 1, and -- The sum of (B+B^) ranges from 1 to 15.

[0014] In a second aspect, the present invention relates to a method [method (P)] for manufacturing a copolymer (P) as defined above, the method comprising the following steps: a) Contacting at least one peroxy(per)fluoropolyether polymer [PFPE peroxide] with at least one perfluorinated compound having the formula (III-p): (III-p) in Each of R 21 to R 23 and R 31 to R 33 is independently a fluorine atom, a perfluorinated straight-chain or branched alkyl group having 1 to 6 carbon atoms. R 10 series oxygen atoms, or perfluorinated straight-chain or branched alkyl groups containing 1 to 24 carbon atoms, with or containing at least one oxygen atom as needed. The t series can be either zero or 1, with 1 being preferable. Each of z* and z** is independently 1 or 2; in The amount of the compound having formula (III-p) is less than 5 wt.% of the amount of the PFPE peroxide; b) React PFPE peroxide and a compound having formula (III) in the presence of UV radiation or heating; c) Fluorination to obtain the copolymer (P).

[0015] In the method according to the invention, it is important to appropriately select the equivalent number of the unsaturated portion having formula (III-p) to be lower than the mole of the peroxide unit in the PFPE peroxide, so as to obtain a branched block copolymer (P) that does not contain the unsaturated portion (also called "functional group") as a side group.

[0016] The copolymer (P) advantageously does not contain side groups that include any portion capable of undergoing further chemical reactions. In particular, the copolymer (P) does not contain unsaturated portions as side groups.

[0017] In a third aspect, the present invention relates to copolymers (P) obtained by the method (P) described above.

[0018] Although the purification step can be performed after step (c), it will be clear to those skilled in the art that the copolymer (P) according to the present invention is obtained as a mixture at the end of step (c) of method (P).

[0019] Therefore, in another aspect, the present invention relates to a mixture [mixture (P)] comprising two or more copolymers (P) as defined above.

[0020] Those familiar with this technique will know that the mixture (P) is obtained by the method (P) described above.

[0021] Advantageously, the mixture (P) can undergo one or more purification steps (also known as "gradation" steps) to obtain individual copolymers (P) characterized by different viscosities.

[0022] In another aspect, the present invention relates to a method for lubricating at least one surface of at least one article, the method comprising contacting the copolymer (P) or the mixture (P) with the at least one surface. Implementation

[0023] For the purposes of this specification and the following claims: - The use of parentheses around identifying symbols or numbers, such as in expressions like "polymer (P)," serves only to better distinguish the symbol or number from the rest of the text, and therefore the parentheses can be omitted; - The acronym "PFPE" stands for "(per)fluoropolyether" and when used as a noun, it refers to either the singular or plural form depending on the context; - The term "(full) fluorinated polyether" is intended to refer to polyether polymers that are fully or partially fluorinated.

[0024] Preferably, in the copolymer (P), the first PFPE chain, the second PFPE chain, A, A^, and C^ are the same as or different from each other.

[0025] Preferably, the perfluorinated alkyl groups are the same as or different from each other.

[0026] Preferably, the perfluorinated alkyl group comprises a straight-chain perfluorinated alkyl group with 1 to 3 carbon atoms.

[0027] Preferably, in the copolymer (P), the at least one first PFPE chain is bonded to the at least one block having formula (I) by means of a σ bond or a group selected from -CF 2-, -CF 2CF 2- or -O-.

[0028] Preferably, in the copolymer (P), the second PFPE chain is bonded to at least one block having formula (I) by means of a σ bond or a group selected from -CF 2-, -CF 2CF 2- or -O-.

[0029] Preferably, in the copolymer (P), (A) and (B) of formula (I) are linked by σ bonds or groups selected from -O-, -CF 2- or -CF 2CF 2-.

[0030] Preferably, in the copolymer (P), each of the first PFPE chain, the second PFPE chain, A in formula (I), and A^ and C^ in formula (IV) comprises repeating units, preferably partially or fully fluorinated chains [chains (Rf)] composed thereof, which are independently selected from the group consisting of: (Rf-i) -CFXO-, where X is F or CF 3; (Rf-ii) -CFXCFXO-, where X is the same or different each time it appears, and is a series F or CF 3, provided that at least one of X is a series -F; (Rf-iii) -CF 2CF 2CW 2O-, where each W is the same or different from the others, and is related to F, Cl, and H; (Rf-iv) -CF 2CF 2CF 2CF 2O-; (Rf-v)-(CF2)j-CFZ-O-, where j is an integer from 0 to 3 and Z is a group having the general formula -OR(fa)-T, where R(fa) is a fluoropolyoxyalkylene chain containing 0 to 10 repeating units, the repeating units being selected from the following: -CFXO-, -CF2CFXO-, -CF2CF2CF2O-, -CF 2CF 2CF 2CF 2O-, where each X is independently F or CF 3 and T-series C 1-C 3 perfluoroalkyl.

[0031] Preferably, the chain (Rf) conforms to the following formula: (R fI) -[(CFX 1O) g1(CFX 2CFX 3O) g2(CF 2CF 2CF 2O) g3(CF 2CF 2CF 2CF 2O) g4]- in - X 1 is selected independently from -F and -CF 3, - X2 and X3 are either the same as or different from each other and are independently -F and -CF3 each time they appear, provided that at least one of the series X is -F; - g1, g2, g3, and g4 are the same or different from each other, and are independent integers ≥ 0, such that g1 + g2 + g3 + g4 is in the range from 2 to 1000; if at least two of g1, g2, g3, and g4 are not zero, then the different repeating units are statistically distributed along the chain in general.

[0032] More preferably, the chain (Rf) is selected from chains having the following formula: (R f-IIA) -[(CF 2CF 2O) a1(CF 2O) a2]- in: - a1 and a2 are independent integers ≥ 0, such that the number average molecular weight is between 1,000 and 100,000; both a1 and a2 are preferably non-zero, wherein the ratio a1 / a2 is preferably between 0.1 and 10; (R f-IIB) -[(CF 2CF 2O) b1(CF 2O) b2(CF(CF 3)O) b3(CF 2CF(CF 3)O) b4]- in: b1, b2, b3, and b4 are independently integers ≥ 0, such that the number average molecular weight is between 1,000 and 100,000; preferably, b1 is 0, and b2, b3, and b4 are > 0, wherein the ratio b4 / (b2+b3) ≥ 1; (R f-IIC) -[(CF 2CF 2O) c1(CF 2O) c2(CF 2(CF 2) cwCF 2O) c3]- in: cw = 1 or 2; c1, c2, and c3 are independently integers ≥ 0, which are chosen such that the number average molecular weight is between 1,000 and 100,000; preferably, c1, c2, and c3 are all > 0, wherein the ratio c3 / (c1+c2) is typically less than 0.2.

[0033] Even better, the chain (Rf) conforms to the following equation (Rf-III): (R f-III) -[(CF 2CF 2O) a1(CF 2O) a2]- in: - a1 and a2 are integers > 0 such that the number average molecular weight is between 1,000 and 100,000, wherein the ratio a1 / a2 is typically between 0.1 and 10, and more preferably between 0.2 and 5.

[0034] Preferably, in equation (II), n is equal to 1 or 2, more preferably an integer of 1.

[0035] Preferably, in formula (II), at least one of the substituents R1 to R4 has a group of formula (III), and the other substituents are each independently selected from fluorine atoms or perfluorinated alkyl chains having 1 to 3 carbon atoms, more preferably fluorine atoms or perfluorinated alkyl chains having 1 carbon atom.

[0036] According to one implementation, in equation (III), t is 0.

[0037] According to another embodiment, in equation (III), t is 1, and R 10 satisfies one of the following formulas: (R 10-i) -(CF 2) d(O) e(CF 2O) fR CF(O) e*(CF 2) d*(CF2O) f* in Each of d, d*, e, e*, f, and f* is independently zero or 1, and R CF series refers to perfluorinated alkyl chains containing 1 to 12, preferably 1 to 8, carbon atoms, with one or more oxygen atoms inserted as needed. (R 10-ii) -O-(C 3F 6O) h-(CF 2) i-(C 3F 6O) jO- Where h = j and h + j ranges from 2 to 6, and i ranges from 2 to 6.

[0038] According to this implementation method, R 10 preferably conforms to the following formula: (R 10-i) -(CF 2) d(O) e(CF 2O) fR CF(O) e*(CF 2) d*(CF2O) f* in d, f, d*, and f* are all zero. e and e* series 1, and The R CF series comprises straight-chain perfluorinated alkyl chains of 1 to 10, preferably 1 to 8, carbon atoms.

[0039] Preferably, in formula (III), z equals 1 and R is a 10-series oxygen atom or, as needed, a divalent perfluorinated alkyl chain containing 1 to 24 carbon atoms with and / or containing at least one oxygen atom.

[0040] Preferably, in formula (III), one of the substituents R11 and R12 is a group of formula (IV), and the other substituent is selected from a fluorine atom or a perfluorinated alkyl chain having 1 to 3 carbon atoms, more preferably a fluorine atom or a perfluorinated alkyl chain having 1 carbon atom.

[0041] Preferably, in formula (III), one of the substituents R13 to R15 has a group of formula (IV), and the other two substituents are independently selected from fluorine atoms or perfluorinated alkyl chains having 1 to 3 carbon atoms, more preferably fluorine atoms or perfluorinated alkyl chains having 1 carbon atom. Even more preferably, the two substituents are identical and are fluorine atoms.

[0042] Preferably, in formula (IV), the a-system 1, the v-system 1, and the B-system have groups of the following formula: -[C(R 1^)(R 2^)-C(R 3^)(R 4^)]-, where R 1^ to R 4^ are each independently identical to each of R 1 to R 4.

[0043] Preferably, the copolymer (P) is characterized by a complex viscosity ranging from 10 Pa*s to 5000 Pa*s, measured at 0.1 rad / s and 25 °C. [] []

[0044] According to the present invention, the copolymer (P) is obtained by the method (P) described above.

[0045] Prior to step (a), the PFPE peroxide may undergo partial reduction of the peroxide bonds, for example by chemical reduction or UV treatment or heat treatment.

[0046] Preferably, the PFPE peroxide system comprises a per-fluoropolyether polymer having two ends, each of which comprises a per-fluoroalkyl chain having 1 to 3 carbon atoms, and optionally contains one or more chlorine atoms or a functional end group selected from fluoropolymers, fluoroformates and ketones, the ends being bonded to the opposite side of the per-fluoropolyether chain, the per-fluoropolyether chain comprising, preferably, the following: repeating units independently selected from the group consisting of formulas (Rf-i) to (Rf-v) as defined above and having a peroxide content (PO) between 0.1 and 4, preferably between 0.1 and 3.5, the peroxide content being defined as the number of grams of active oxygen in 100 g of PFPE peroxide (Mw=16).

[0047] Preferably, in the compound having formula (III-p), when t is 1, two, three, or four unsaturated portions are bonded to the same or different atoms belonging to R 10, preferably carbon atoms.

[0048] Preferably, the at least one compound having formula (III-p) conforms to the following formula: CF² = CF(R 10) tCF = CF² in t is zero or 1. R 10 satisfies one of the following formulas: (R 10-i) -(CF 2) d(O) e(CF 2O) fR CF(O) e*(CF 2) d*(CF2O) f* in Each of d, d*, e, e*, f, and f* is independently zero or 1, and R CF series refers to perfluorinated alkyl chains containing 1 to 12, preferably 1 to 8, carbon atoms, with one or more oxygen atoms inserted as needed. (R 10-ii) -O-(C 3F 6O) h-(CF 2) i-(C 3F 6O) jO- Where h = j and h + j ranges from 2 to 6, and i ranges from 2 to 6.

[0049] Preferably, the compound having formula (III-p) is selected from the group consisting of, more preferably, the following: CF 2=CFCF=CF 2 CF 2=CFOCF=CF 2 CF 2=CFCF 2OCF 2CF=CF 2 CF 2=CFO-(CF 2) 3CF=CF 2 CF 2=CFCF 2O(CF 2) 3OCF 2-CF=CF 2 CF 2=CFCF 2CF=CF 2 CF 2=CF(CF 2) 2CF=CF 2 CF 2=CF(CF 2) 3CF=CF 2 CF 2=CF(CF 2) 4CF=CF 2 CF 2=CFOCF 2OCF=CF 2 CF 2=CFO(CF 2) 2OCF=CF 2 CF 2=CFO(CF 2) 3OCF=CF 2 CF 2=CFO(CF 2) 4OCF=CF 2 CF 2=CF(CF 2) 2OCF=CF 2 CF 2=CF(CF 2) 3OCF=CF 2 CF 2=CF(CF 2) 4OCF=CF 2 CF 2=CFCF 2O(CF 2) 2OCF 2O-CF=CF 2 CF 2=CFCF 2O(CF 2) 3OCF 2O-CF=CF 2 CF 2=CFCF 2O(CF 2) 4OCF 2OCF=CF 2 CF 2=CFCF 2O(CF 2) 6OCF 2CF=CF 2 CF 2=CFO-CF 2O-(CF 2) 2O-CF 2O-CF=CF 2 CF 2=CFO-CF 2O-(CF 2) 3O-CF 2O-CF=CF 2 CF 2=CFO-CF 2O-(CF 2) 4O-CF 2O-CF=CF 2 CF 2=CFO-(CF 2O) 6-CF=CF 2 CF 2=CFO-(CF 2CF 2O) 2-CF=CF 2 CF 2=CFO-(CF 2CF 2O) 2-CF 2OCF=CF 2 CF 2=CFO(C 3F 6O) h-(CF 2) i-(C 3F 6O) j-OCF=CF 2 Where h and j are the same and Their sum series ranges from 2 to 6, and the i series ranges from 2 to 6.

[0050] According to a particularly preferred embodiment, the at least one compound having formula (III-p) conforms to the following formula: CF² = CF(R 10) tCF = CF² Where t is 1 and R 10 conforms to the following formula: (R 10-i) -(CF 2) d(O) e(CF 2O) fR CF(O) e*(CF 2) d*(CF2O) f* in d, f, d*, and f* are all zero. e and e* series 1, and The R CF series comprises straight-chain perfluorinated alkyl chains of 1 to 10, preferably 1 to 8, carbon atoms.

[0051] Preferably, in step (a), the amount of the compound having formula (III-p) is less than 3 wt.%, or even more preferably less than 1 wt.%, of the PFPE peroxide.

[0052] Those familiar with the technique will readily understand that, as the reaction proceeds and the copolymer (P) is obtained, the unsaturated portion in the compound having formula (III-p) becomes the saturated portion in the copolymer (P), such that substituents R21 to R23 in formula (III-p) become substituents R1 to R3 in formula (III) of the copolymer (P), substituent R31 becomes any one of substituents R11 or R12 in formula (III), and substituents R32 and R33 become any one of substituents R13 to R15 in formula (III) of the copolymer (P).

[0053] Steps (a) and (b) can be performed in the presence of a fluorinated solvent. Preferably, the fluorinated solvent is selected from the group consisting of: perfluorocarbons, hydrofluorocarbons, perfluoropolyethers, and hydrofluoropolyethers.

[0054] Preferably, step (b) is performed in the presence of UV radiation for a period of 2 to 60 hours.

[0055] Preferably, step (b) is carried out in the presence of UV radiation at a temperature ranging from -60°C to +60°C, more preferably from -20°C to +40°C, and even more preferably from 0°C to 30°C.

[0056] As an alternative, step (b) can be performed under heat treatment, preferably by heating at a temperature from 100°C to 250°C.

[0057] Those skilled in the art will know that the polymer obtained at the end of step (b) has a peroxide content (PO) of less than 0.05, preferably less than 0.001.

[0058] Preferably, step (c) is performed by fluorine treatment in the presence of anhydrous nitrogen gas.

[0059] Preferably, the method (P) includes a solvent removal step (d) and / or a fractionation step (e) after step (c).

[0060] The solvent removal step (d) can be carried out by evaporation, for example by vacuum distillation.

[0061] The fractionation step (e) can be carried out by solvent extraction. When the fractionation step is carried out by precipitation fractionation, supercritical CO2, hexafluoroxylene, or hydrofluorocarbons and mixtures thereof are used as solvents. Supercritical CO2 is preferred.

[0062] As explained above, the purification step can be performed after step (c) or step (d). Those skilled in the art will understand that the copolymer (P) according to the invention is obtained as a mixture (P) at the end of step (c) or step (d) of the method (P), wherein there are copolymers (P) characterized by different viscosities and / or molecular weights and / or substituents.

[0063] Copolymers (P) are advantageously used as lubricants, especially in harsh environments, such as those subjected to a wide range of operating temperatures.

[0064] The copolymer (P) or mixture (P) can be used as is or mixed with one or more additives known to those skilled in the art of lubrication to obtain a composition [composition (CL)].

[0065] For example, the composition (CL) may contain other suitable lubricants as base oils, such base oils being selected from the group consisting of partially fluorinated, fully fluorinated and hydrogenated base oils, provided that the base oils are capable of forming a solution with the copolymer (P).

[0066] Non-limiting examples of fully fluorinated lubricant base oils are based on Those identified as compounds (1)-(8) in [EP 2100909]A (Solvezux).

[0067] For example, suitable additives are selected from thickeners, rust inhibitors, antioxidants, heat stabilizers, pour point depressants, anti-wear agents including those used under high pressure, dispersants, tracers, dyes, talc, and inorganic fillers.

[0068] Examples of thickeners include talc, silicon dioxide, boron nitride, polyurea, alkali metal or alkaline earth metal terephthalates, calcium soaps and lithium soaps and their complexes, and PTFE (polytetrafluoroethylene); among them, PTFE is preferred.

[0069] Examples of dispersants include surfactants, preferably nonionic surfactants, more preferably (per)fluoropolyether surfactants and (per)fluoroalkyl surfactants.

[0070] Solvents can also be used if required by the application.

[0071] Examples of solvents include fluorinated or partially fluorinated solvents such as Galden® PFPE, Novec® HFE, and other organic solvents such as fluoroalkanes, fluoroaromatic compounds, fluoroalkyl ethers, fluoroalkylamines, fluoroalcohols, ketones such as methyl ethyl ketones, alcohols such as isopropanol, esters such as butyl acetate, hydrofluorocarbons, etc.

[0072] There are no particular limitations on articles that can benefit from the lubricating properties of the copolymer (P), mixture (P), or composition (CL) according to the present invention.

[0073] The article preferably includes at least one metal surface.

[0074] Examples of the articles are pumps used in oil and gas applications, such as electric submersible pumps; rotating machines, such as steam turbines and gas turbines; electrical connectors; bearings for fan clutches or cooling fans; or automatic clutches for heavy-duty trucks, and more particularly, bearings for said clutches.

[0075] The copolymers (P), mixtures (P) or compositions (CL) according to the invention can be advantageously used as damper fluids in damping devices.

[0076] Therefore, in another aspect, the present invention relates to a method for counteracting vibrations and / or shocks in a device, the method comprising providing an apparatus including a damper device comprising at least one copolymer (P), mixture (P), or composition (CL) as defined above.

[0077] If any disclosure of any patent, patent application, or publication incorporated herein by reference conflicts with the description of this application to the extent that it may lead to ambiguity in terminology, then this description shall take precedence.

[0078] The invention will now be described with reference to the following examples, which are merely illustrative and not intended to limit the scope of the invention. [] [Experimental Section]

[0079] [Material] [] []

[0080] Perfluoropolyether oil with peroxide has the following formula: TO-(CF 2CF 2O) m(CF 2O) n-(O) h-T' Number average molecular weight (Mn) = 48600 g / mol m / n = 1.0 and PO = 1.65% T, T'=-CF 3(83%), -C(=O)F(6%), -CF 2C(=O)F(11%) It was obtained by Solvay Specialty Polymers Italy SpA.

[0081] Galden® HT200 is sourced from Solvay Specialty Polymers, Italy.

[0082] The perfluoro(bisvinyl ether) (PBVE) was obtained by Anles LLC.

[0083] Hexafluorobenzene is obtained from Sigma Aldrich.

[0084] [method] [] []

[0085] [19F-NMR] [Spectroscopic method:] [] The structure, number-average molecular weight, and composition of the PFPE oils reported in the following examples were obtained using a Varian Mercury 200 MHz spectrometer designed for fluorine nuclei. 19F-NMR spectra were obtained on pure samples using CFCl3 as an internal standard. Hexafluorobenzene was also used as a solvent.

[0086] [Peroxide content] [(PO)] [Confirmed:] [] Peroxide content (PO) is expressed as grams of oxygen peroxide per 100 g of polymer. Peroxide content was analyzed by iodometric titration using a Mettler DL40 apparatus equipped with a platinum electrode. The sensitivity limit for PO determination is 0.0002%.

[0087] [Determination of complex viscosity:] [] []According to ISO 6721 Part 10, complex viscosity was measured by frequency sweep test using an MCR502 Anton-Paar rheometer with a parallel plate geometry (25 mm diameter).

[0088] Gel permeation chromatography (GPC) [:] [] [] HFE7100 was used as the eluent, and analysis was performed using a mixed CCD column and a Waters 410 refractometer detector.

[0089] [Example] [1 -] [Copolymer] [(P-1)] [The synthesis of] [] []

[0090] The reaction was carried out using a 1000 mL cylindrical photochemical glass reactor equipped with a high-pressure mercury lamp (HANAU TQ150) enclosed in a quartz cylinder, a magnetic stirrer, a thermocouple, and a condenser.

[0091] 200.3 g of starting perfluoropolyether peroxide oil was added to a photochemical reactor along with 1501 g of Galden® HT200 and 1.30 g of PBVE and stirred thoroughly to obtain a homogeneous mixture. The reaction mixture was then cooled to approximately 10°C using an ice / water bath, and nitrogen was purged into the system at a rate of 1.0 Nl / h. The UV lamp was then turned on.

[0092] After irradiation for 55 hours, the lamp was turned off and the reaction mixture was transferred to a second glass reactor and fluorinated for a total of 24 hours at 40°C in the presence of UV radiation with fluorine gas at a rate of 1.0 Nl / h. 19F-NMR analysis confirmed complete fluorination of the product and the absence of -CF2COF and -COF ends at the chain ends.

[0093] The obtained solution was distilled at 240°C for 4 h in a round-bottom flask equipped with a magnetic stirrer to remove the solvent.

[0094] Distillation is first carried out at atmospheric pressure, and then at reduced pressure (0.1 mbar) until the solvent is completely removed.

[0095] 163.6 g of copolymer (P-1) in the form of a transparent, viscous oil was obtained as a residue and analyzed by iodometric titration to confirm the complete removal of the peroxide unit.

[0096] 19F-NMR analysis confirmed the absence of residual peroxides. The polymer (P-1) has m / n=1.0 and T, T'=-CF 3.

[0097] [Example] [2 -] [No] [PBVE] [Comparative polymers] [(C-1^)] [The synthesis of] [] []

[0098] This comparative example uses the same photochemical equipment and perfluoropolyether peroxide precursor as in Example 1.

[0099] 199.9 g of the initial perfluoropolyether peroxide oil was loaded into the photochemical reactor along with 1502 g of Galden® HT200 and stirred thoroughly to obtain a homogeneous mixture.

[0100] The synthesis was then carried out as described in Example 1. 19F-NMR analysis confirmed the complete fluorination of the product and the absence of -CF2COF and -COF ends at the chain ends.

[0101] Distillation is performed as described in Example 1.

[0102] 172.4 g of the comparative polymer (C-1^) in the form of a transparent, viscous oil was obtained as a residue and analyzed by iodometric titration to confirm the complete removal of the peroxide unit.

[0103] 19F-NMR analysis confirmed the absence of residual peroxides. The contrast copolymer (C-1^) has m / n=1.0 and T, T'=-CF 3.

[0104] The increased molecular weight distribution and complex viscosity of the copolymer (P-1) according to the invention confirm chain elongation relative to the comparative polymer (C-1^).

Claims

1. A copolymer (P) having two ends and comprising first and second (per)fluoropolyether chains [PFPE chains] each having two ends, wherein the ends of the copolymer (P) comprise perfluorinated alkyl groups, wherein the first ends of the first and second PFPE chains comprise perfluorinated alkyl groups and the second ends of the first and second PFPE chains are bonded to each other by blocks having formula (I): (I) -[AB]- where A is a PFPE chain and B is a portion conforming to formula (II): (II) where n is an integer from 1 to 3; R1 to R4 are each independently selected from the group comprising: fluorine atoms, perfluorinated linear or branched alkyl groups having 1 to 6 carbon atoms, and groups having formula (III): (III) -(R10)t[C(R11)(R12)-C(R13)(R14)(R15)]z R10 refers to an oxygen atom, or, as needed, a divalent / trivalent / tetravalent perfluorinated alkyl chain containing 1 to 24 carbon atoms with and / or containing at least one oxygen atom; t refers to zero or 1; z refers to an integer from 1 to 3; R11 to R15 are each independently selected from the group consisting of: fluorine atoms, perfluorinated straight-chain or branched alkyl groups having 1 to 6 carbon atoms, and groups having formula (IV): -[(A^)a-(B^)v]-(C^)-T (IV) where A^ refers to a PFPE chain, a refers to zero or 1, v refers to zero or an integer from 1 to 3, B^ refers to a group having formula -[C(R1^)(R2^)-C(R3^)(R4^)]-, where R1^ to R4^ each independently have the meaning defined above for R1 to R4, C^ refers to a PFPE chain, and T refers to a perfluorinated alkyl group; wherein: -- The A and B in formula (I) and the A^ and B^ in formula (IV) are systematically distributed, -- at least one of R1 to R4 has a group of formula (III), -- one of R11 or R12 and one of R13 to R15 have a group of formula (IV), wherein a is 1, and -- the sum of (B+B^) is from 1 to 15.

2. The copolymer (P) as claimed in claim 1, wherein, - The first and second PFPE chains, as defined in claim 1, are the same as or different from each other; and / or - Each of the perfluorinated alkyl groups is the same as or different from each other, and is a straight-chain perfluorinated alkyl group comprising 1 to 3 carbon atoms; and / or - The first PFPE chain is bonded to the at least one block having formula (I) by means of a σ bond or a group selected from -CF2-, -CF2CF2- or -O-; and / or - The second PFPE chain is bonded to the at least one block having formula (I) by means of a σ bond or a group selected from -CF2-, -CF2CF2- or -O-; - The A and B in formula (I) are linked by a σ bond or a group selected from -CF2- or -CF2CF2-.

3. The copolymer (P) of either claim 1 or 2, wherein, Each of the first and second PFPE chains, A in formula (I), and A^ and C^ in formula (IV) are independently partially or fully fluorinated chains [chains (Rf)] containing repeating units, which are independently selected from the group consisting of: (Rf-i) -CFXO-, where X is F or CF3; (Rf-ii) -CFXCFXO-, where X is the same or different each time it appears, and is F or CF3, provided that at least one of X is of the -F series; (Rf-iii) -CF2CF2CW2O-, where each W is the same or different from one another, and is of the F, Cl, or H series; (Rf-iv) -CF2CF2CF2CF2O-; (Rf-v) -(CF2)j-CFZ-O-, where j is an integer from 0 to 3 and Z is a group having the general formula -OR(fa)-T, where R(fa) is a fluoropolyoxyalkyl chain containing 0 to 10 repeating units, the repeating units being selected from the following: -CFXO-, -CF2CFXO-, -CF2CF2CF2O-, -CF2CF2CF2CF2O-, where each X is independently F or CF3 and T is a C1-C3 perfluoroalkyl group.

4. The copolymer (P) as claimed in claim 1, wherein, In formula (II): - n is an integer equal to 1 or 2; and / or - at least one of the substituents R1 to R4 is a group having formula (III) as defined in claim 1, and the other substituents are each independently selected from fluorine atoms or perfluorinated alkyl chains having 1 to 3 carbon atoms.

5. The copolymer (P) as claimed in claim 1, wherein, In formula (III): - t series 0; or - t series 1 and R10 conforms to one of the following formulas: (R10-i) -(CF2)d(O)e(CF2O)fRCF(O)e*(CF2)d*(CF2O)f* where each of d, d*, e, e*, f and f* is independently zero or 1, and the RCF series is a perfluorinated alkyl chain containing 1 to 12 carbon atoms with one or more oxygen atoms inserted as needed (R10-ii) -O-(C3F6O)h-(CF2)i-(C3F6O)jO- where h=j and h+j series from 2 to 6, and i series from 2 to 6.

6. The copolymer (P) as claimed in claim 1, wherein, In formula (III): - z equals 1 and R10 is an oxygen atom or, as desired, a divalent perfluorinated alkyl chain containing 1 to 24 carbon atoms with and / or containing at least one oxygen atom; and / or - one of the substituents R11 and R12 is a group having formula (IV) as defined in claim 1, and the other substituent is selected from fluorine atoms or a perfluorinated alkyl chain having 1 to 3 carbon atoms; and / or - one of the substituents R13 to R15 is a group having formula (IV), and the other two substituents are independently selected from fluorine atoms or a perfluorinated alkyl chain having 1 to 3 carbon atoms.

7. The copolymer (P) as claimed in claim 1, wherein, In formula (IV): - a-system 1, v-system 1 and B^-system have a group of formula -[C(R1^)(R2^)-C(R3^)(R4^)]-, wherein R1^ to R4^ are each independently selected from the group consisting of: fluorine atoms, perfluorinated straight-chain or branched alkyl groups having 1 to 6 carbon atoms, or a group of formula (III) as defined in claim 1.

8. The copolymer (P) of claim 1, said copolymer (P) having a complex viscosity from 10 Pa*s to 2000 Pa*s as measured at 0.1 rad / s and 25°C according to ISO 6721 Part 10.

9. The copolymer (P) of claim 1, wherein the copolymer (P) does not contain side groups comprising: portions capable of undergoing chemical reactions.

10. A mixture (P) comprising two or more copolymers (P) of any one of claims 1 to 9.

11. A method (P) for manufacturing a copolymer (P) as claimed in any one of claims 1 to 9 or a mixture (P) as claimed in claim 10, said method comprising the steps of: a) contacting at least one peroxide (per)fluoropolyether polymer [PFPE peroxide] comprising a (per)fluoropolyether chain having two ends with at least one perfluorinated compound having the formula (III-p), each of said ends comprising a (per)fluoroalkyl chain having from 1 to 3 carbon atoms, and optionally comprising one or more chlorine atoms or functional end groups selected from fluoropolymers, fluoroformates and ketones, said ends being bonded to opposite sides of said (per)fluoropolyether chain, said (per)fluoropolyether chain comprising: repeating units independently selected from the group consisting of formulas (Rf-i) to (Rf-v) as defined in claim 3 and having a peroxide content (PO) between 0.1 and 4, said peroxide content being defined as the number of grams of active oxygen in 100 g of PFPE peroxide (Mw = 16), (III-p) wherein each of R21 to R23 and R31 to R33 is independently a fluorine atom, a perfluorinated straight-chain or branched alkyl group having 1 to 6 carbon atoms, R10 is an oxygen atom, a perfluorinated straight-chain or branched alkyl group having 1 to 24 carbon atoms with and / or containing at least one oxygen atom inserted as needed, t is zero or 1; each of z* and z** is independently 1 or 2; wherein the amount of the compound having formula (III-p) is less than 5 wt.% of the amount of the PFPE peroxide; b) reacting the PFPE peroxide and the compound having formula (III) in the presence of UV radiation or heating; c) fluorination to obtain the copolymer (P).

12. As in the method (P) of request item 11, wherein, The t-series 1, and two, three or four unsaturated parts are bonded to the same or different carbon atoms belonging to R10.

13. As in the method (P) of request item 12, wherein, The at least one compound having the formula (III-p) conforms to the following formula: CF2=CF(R10)tCF=CF2 where t is zero or 1, R10 conforms to one of the following formulas: (R10-i) -(CF2)d(O)e(CF2O)fRCF(O)e*(CF2)d*(CF2O)f* where each of d, d*, e, e*, f and f* is independently zero or 1, and RCF is a perfluorinated alkyl chain containing 1 to 12 carbon atoms with one or more oxygen atoms inserted as needed (R10-ii) -O-(C3F6O)h-(CF2)i-(C3F6O)jO- where h=j and h+j is from 2 to 6, and i is from 2 to 6.

14. The method (P) of any one of claims 11 to 13, said method (P) comprising: - A step prior to step (a) to partially reduce the peroxide bonds in the PFPE peroxide; And / or - after step (c), the solvent removal step (d) and / or the fractionation step (e).

15. A composition (CL) comprising a copolymer (P) as claimed in claims 1 to 9 or a mixture (P) as claimed in claim 10, and at least one base oil selected from the group consisting of partially fluorinated, fully fluorinated, and hydrogenated base oils, provided that the base oil is capable of forming a solution with the copolymer (P) and, if desired, at least one additive selected from thickeners, rust inhibitors, antioxidants, heat stabilizers, pour point depressants, anti-wear agents, dispersants, tracers, dyes, talc, and inorganic fillers.

16. A method for lubricating at least one surface of at least one article, the method comprising contacting the at least one surface with a copolymer (P) as claimed in claims 1 to 9, or a mixture (P) as claimed in claim 10, or a composition (CL) as claimed in claim 15.

17. As in request item 16, wherein, The products are selected from pumps used in oil and gas applications, such as electric submersible pumps; rotating machines, such as steam turbines and gas turbines; electrical connectors; fan clutches or bearings for cooling fans; or automatic clutches for heavy-duty trucks.

18. A method for counteracting vibrations and / or shocks in a device, the method comprising providing an apparatus including a damper device comprising at least one copolymer (P) as claimed in claims 1 to 9, or a mixture (P) as claimed in claim 10, or a composition (CL) as claimed in claim 15.