Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M147/00—Lubricating compositions characterised by the additive being a macromolecular compound containing halogen
  • C10M147/04—Monomer containing carbon, hydrogen, halogen and oxygen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
  • C10M169/06—Mixtures of thickeners and additives
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
  • C10M2213/04—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions obtained from monomers containing carbon, hydrogen, halogen and oxygen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
  • C10M2213/06—Perfluoro polymers
  • C10M2213/062—Polytetrafluoroethylene [PTFE]
  • C10M2213/0626—Polytetrafluoroethylene [PTFE] used as thickening agents
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/04—Molecular weight; Molecular weight distribution
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/02—Pour-point; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/10—Inhibition of oxidation, e.g. anti-oxidants
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2050/00—Form in which the lubricant is applied to the material being lubricated
  • C10N2050/10—Semi-solids; greasy
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2070/00—Specific manufacturing methods for lubricant compositions

Definitions

• the present invention relates to a lubrication method, to polymers for use in such method and to lubricant compositions containing such polymers.
• Polyoxyalkylene glycols are used in a variety of applications, such as the lubrication of gears, transmission systems, air conditioning (A/C) systems, metalworking fluids as well as hydraulic fluids.
• PAGs can be formulated as aqueous or non-aqueous compositions containing specific additive packages to improve their performances.
• PFPEs Perfluoropolyethers
• US 7230140 ASAHI GLASS COMPANY, LIMITED 20050908 discloses a PFPE derivative of the formula (I): HO-(CH 2 CH 2 O) r (CH 2 CH(OH)CH 2 O) p -CH 2 CF 2 O(CF 2 CF 2 O) m CF 2 CH 2 O-(CH 2 CH(OH)CH 2 O) q (CH 2 CH 2 O) s -H (I) wherein: m is an integer of from 3 to 200, each of r and s, which are independent of each other, and is an integer of from 0 to 100, and each of p and q, which are independent of each other and, is an integer of from 0 to 100.
• the derivative of formula (I) is said to be useful as lubricating oil or as coating agent and is said to be less likely to undergo decomposition, and to be free from deterioration during its use. It is worth noting that the PFPE backbone of the derivative of formula (I) comprises only -CF 2 CF 2 O- repeating units; indeed, in this document it is stated that PFPE derivatives comprising also -CF 2 O- units further contain -OCF 2 O- units that may cause decomposition or deterioration (reference is made to col. 1, lines 21 – 25).
• this prior art document teaches to improve the stability of PFPE lubricants by selecting a PFPE chain without -CF 2 O- units.
• the description discloses in particular a preferred compound of formula: HO(CH 2 CH 2 O) r CH 2 CF 2 O(CF 2 CF 2 O) m CF 2 CH 2 O(CH 2 CH 2 O) s H (Ic) wherein r and s are simultaneously 1 and a compound of formula: HO(CH 2 CH(OH)CH 2 O) p CH 2 CF 2 O(CF 2 CF 2 O) m CF 2 CH 2 O(CH 2 CH(OH)CH 2 O) q H (Id) wherein p and q are simultaneously 1.
• Examples 6-1, 6-2 and 7 illustrate the synthesis of certain compounds complying with formulae (Ic) and (Id) above. Nevertheless, this prior art does not teach to prepare compounds complying formula (I) having r and s higher than 1.
• fluoropolyether compounds (A) are useful, inter alia , as lubricants, especially in the form of solutions with organic solvents (par. [0013] and [0024]), and that they are less subject to deterioration, as they do not contain -OCF 2 O- units in their molecular structure.
• group Y is an at least trivalent group which does not contain -OCF 2 O- units.
• this document teaches away from PFPE lubricants comprising -CF 2 O- repeating units.
• this prior art does not teach to synthesise fluoropolyether compounds having more than one ethoxylated units in the chain ends.
• US 2008132664 ASAHI GLASS COMPANY, LIMITED 20080605 relates to an ether composition comprising a polyether compound (A) and an ether compound (B), said composition being useful, inter alia , as lubricant (see par. [0007] and [0025]).
• Examples of ether compounds (B) comply with formulae (B-4) and (B-5) below: (B-4) HOCH 2 CH(OH)CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) d7 (CF 2 O) g2 CF 2 CH 2 OCH 2 CH(OH)CH 2 OH (B-5) HOCH 2 CH 2 OCH 2 CF 2 O(CF 2 CF 2 O) d8 (CF 2 O) g3 CF 2 CH 2 OCH 2 CH 2 OH.
• d7 is a positive number of at least 1
• g2 is a positive number of at least 0, and the average molecular weight of the compound represented by formula (B-4) is from 500 to 2,000;
• d8 is a positive number of at least 1
• g3 is a positive number of at least 0.
• the average molecular weight of the compound represented by the formula (B-5) is from 500 to 2, 000.
• polyether compound (A) contains at least two -CF 2 CF 2 O- units and does not contain -OCF 2 O- units and that this document teaches that high chemical stability can be achieved thanks to the presence of such compound (A).
• compound (B-4) comprise only one -OCH 2 CH(OH)CH 2 - unit at each end of the PFPE chain, while compound (B-5) comprises only one –OCH 2 CH 2 - unit at each chain end of the PFPE chain.
• FIG. 1 illustrates the results of a thermogravimetric analysis (TGA) carried out on two polymers according to the present invention.
• polymers comprising a (per)fluoropolyether chain having two chain ends, wherein one or both chain ends bear a definite number of oxyalkylene units free from fluorine atoms show higher thermal stability, improved lubrication properties (such as lower wear) and improved performances at extreme pressures with respect to PAGs. It has also been observed that such polymers are endowed with improved compatibility with PAGs. Therefore, they are suitable for use in lubrication methods comprising applying such polymers or compositions containing them to a surface to be lubricated.
• the polymers for use in the method of the invention comprise a partially or fully fluorinated, straight or branched, polyoxyalkylene chain (chain R f ) having two chain ends, wherein one or both chain end(s) bear(s) a hydroxy-, alkoxy- or acyloxy- terminated polyoxyalkylene chain free from fluorine atoms (chain R a ), said chain comprising from 4 to 50 fluorine-free oxyalkylene units, said units being the same or different from one another and being selected from -CH 2 CH 2 O- and -CH 2 CH(J)O- , wherein J is independently straight or branched alkyl or aryl, preferably methyl, ethyl or phenyl, with the proviso that, if both chain ends bear a hydroxy-terminated chain R a comprising only -CH 2 CH 2 O- units, chain R f does not consist only of -CF 2 CF 2 O- units.
• PFPE-PAGs polymers for use in the method of the invention will be herein after also generically referred to as "PFPE-PAGs" and, more specifically, as “mono- or bi-functional "PFPE-PAGs, depending on whether one or both chain ends bear a chain R a .
• the invention further relates to lubricant compositions comprising the PFPE-PAGs and to methods for preparing the PFPE-PAGs.
• (per)fluoropolyether stands for “fully or partially fluorinated polyether”.
• PFPE (per)fluoropolyether
• (halo)alkyl denotes a hydrocarbon group wherein one or more hydrogens can be replaced by one or more halogen atoms, preferably fluorine atoms.
• the PFPE-PAGs for use in the method of the invention comply with formula (I) below: A-O-R f -(CF 2 ) x -CFZ-CH 2 -O-R a (I) wherein: - R f is a (per)fluoropolyoxyalkylene chain having an average number molecular weight M n ranging from 100 to 8,000, preferably from 300 to 6,000, more preferably from 800 to 3,000, and comprising, preferably consisting of, repeating units, which may be equal to or different from one another, selected from: (i) -CFXO-, wherein X is F or CF 3 , (ii) -CFXCFXO-, wherein X, equal or different at each occurrence, is F or CF 3 , with the provision that at least one of X is –F, (iii) -CF 2 CF 2 CW 2 O-, wherein each of W, equal or different from each other, are F or H,
• Preferred R f chains in the PFPE-PAGs of formula (I) are those selected from formulae (a) - (c) here below: (a) -(CF 2 O) n (CF 2 CF 2 O) m (CF 2 CF 2 CF 2 O) p (CF 2 CF 2 CF 2 O) q - wherein m, n, p, q are 0 or integers selected in such a way as chain R f meets the above number average molecular weight requirement, with the proviso that if, p and q are simultaneously 0, n is not 0; when m is other than 0, the m/n ratio is preferably between 0.1 and 20; when (m+n) is other than 0, (p+q)/(m+n) is preferably between 0 and 0.2; (b) -(CF 2 CF(CF 3 )O) a (CF 2 CF 2 O) b (CF 2 O) c (CF(CF 3 )O) d
• PFPE-PAGs of formula (I) wherein chain R f complies with formula (a) as defined above are particularly preferred in the method of the invention.
• chain R a complies with formula (R a -I) below: (R a -I) -(CH 2 CH 2 O) r (CH 2 CH(CH 3 )O) s (CH 2 CH(CH 2 CH 3 )O) t (CH 2 CH(Ph)O) u R 1 wherein r, s, t and u are independently selected from 0 and a positive number, with r+s+t+u ranging from 4 to 50, preferably from 4 to 15, more preferably from 4 to 10, and R 1 is selected from hydrogen, C 1 -C 4 straight or branched alkyl, preferably methyl, and -C(O)R 2 , wherein R 2 is C 1 -C 4 straight or branched (halo)alkyl, with the proviso that, if chain R f of compounds (I) comprises only -CF 2 CF 2 O- units and bears at both ends a chain (R
• r is a positive number ranging from 4 to 15, preferably from 4 to 10, s, t and u are 0 and R 1 is selected from hydrogen or methyl, with the proviso that, if chain R f of compounds (I) comprises only -CF 2 CF 2 O- units and bears at both ends a chain (R a -I), R 1 is not hydrogen.
• r, t and u are 0, s is a positive number ranging from 4 to 15, preferably from 4 to 10, and R 1 is selected from hydrogen or methyl.
• r and s are positive numbers and t and u are 0, r+s ranges from 4 to 15, preferably from 4 to 10, and R 1 is selected from hydrogen or methyl.
• the PFPE-PAGs are bifunctional PFPE-PAGs complying with formula (I-A) below: R a -O-CH 2 -CF 2 -O-R f -CF 2 -CH 2 -O-R a (I-A) wherein: - R a is as defined above and - R f complies with formula (a) as defined above.
• the PFPE-PAGs are monofunctional PFPE-PAGs complying with formula (I-B) below: A-O-R f -CF 2 -CH 2 -O-R a (I-B) wherein: - A is a straight or branched C 1 -C 4 perfluoroalkyl group wherein one fluorine atom can be substituted by one chlorine atom or one hydrogen atom, with the proviso that, if chlorine is present in group A, it is in a molar amount lower than 2% with respect to the overall amount of end groups, - R a is as defined above and - R f complies with formula (a) as defined above.
• bifunctional PFPE-PAGs of formula (I-A) are preferred.
• a preferred group of PFPE-PAGs of formula (I) complies with formula (I*) below: A-O-R f -(CF 2 ) x -CFZ-CH 2 -O-R a (I*) wherein: - R f is a (per)fluoropolyoxyalkylene chain having an average number molecular weight M n ranging from 100 to 8,000, preferably from 300 to 6,000, more preferably from 800 to 3,000, and comprising, preferably consisting of, repeating units, which may be equal to or different from one another, selected from (i) -CFXO-, wherein X is F or CF 3 , (ii) -CFXCFXO-, wherein X, equal or different at each occurrence, is F or CF 3 , with the proviso that at least one of X is –F, (iii) -CF 2 CF 2 CW 2 O-, wherein each of W, equal or different from each other, are F
• Preferred R f chains in the PFPE-PAGs of formula (I*) are those selected from formulae (a*) - (c*) here below: (a*) -(CF 2 O) n (CF 2 CF 2 O) m (CF 2 CF 2 CF 2 O) p (CF 2 CF 2 CF 2 O) q - wherein m, n, p, q are 0 or integers selected in such a way as chain R f meets the above number average molecular weight requirement; when m is other than 0, the m/n ratio is preferably between 0.1 and 20; when (m+n) is other than 0, (p+q)/(m+n) is preferably between 0 and 0.2; (b*) -(CF 2 CF(CF 3 )O) a (CF 2 CF 2 O) b (CF 2 O) c (CF(CF 3 )O) d - wherein a, b, c, d are 0 or
• a first group of preferred compounds (I*) complies with formula (I*-A) below: R a -O-CH 2 -CF 2 -O-R f -CF 2 -CH 2 -O-R a (I*-A) in which: - R f complies with formulae (a*) – (c*) as defined above; and - R a complies with formula (R a -I*) as defined above.
• chain R f complies with formula (a*).
• a second group of compounds (I*) complies with formula (I*-B) below: A-O-R f -CF 2 -CH 2 -O-R a (I*-B) in which: - R f complies with formulae (a*) – (c*) as defined above; and - R a complies with formula (R a -I*) as defined above, and A is a straight or branched C 1 -C 4 perfluoroalkyl group wherein one fluorine atom can be substituted by one chlorine atom or one hydrogen atom, with the proviso that, if chlorine is present in group A, it is in a molar amount lower than 2% with respect to the overall amount of end groups .
• chain R f complies with formula (a*).
• Preferred compounds (I*-A) and (I*-B) are those wherein r, t and u are 0 and s is a positive number ranging from 4 to 15, preferably from 4 to 10, and those wherein r+s is a positive number ranging from 4 to 15, preferably from 4 to 10, and t and u are 0.
• R 1 is methyl or C(O)CH 3 .
• PFPE-PAGs of formula (I*) represent a further aspect of the present invention.
• the PFPE-PAGs for use in the method of the invention can be obtained by reaction of a mono- or bi-functional PFPE alcohol with an alkoxylating agent in such an amount as to obtain from 4 to 50, preferably from 4 to 15, more preferably from 4 to 10, oxyalkylene units at one or both chain ends.
• the mono- or bi-functional PFPE alcohol complies with formula (II) below: Y-O-R f -(CF 2 ) x -CFZ-CH 2 -OH (II) wherein: - R f , x and Z are as defined above; - Y is (CF 2 ) x -CFZ-CH 2 -OH, wherein x and Z are as defined above, or is selected from straight or branched C 1 -C 4 perfluoroalkyl groups wherein one fluorine atom can be substituted by one chlorine atom or one hydrogen atom, with the proviso that, if chlorine is present in group A, it is in a molar amount lower than 2% with respect to the overall amount of end groups and the alkoxylating agent is selected from ethylene oxide, propylene oxide, 1,2-butylene oxide and styrene oxide and a mixture of two or more thereof.
• bifunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) as defined above wherein R 1 is hydrogen
• R a a bifunctional PFPE alcohol of formula (II-A) below: HO-CH 2 -CF 2 -O-R f -CF 2 -CH 2 -OH (II-A) wherein R f complies with formula (a) as defined above with ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide or with a mixture of two or more thereof.
• Monofunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) as defined above wherein R 1 is hydrogen can instead be obtained by reaction of a monofunctional PFPE alcohol of formula (II-B) below: A-O-R f -CF 2 -CH 2 -OH (II-B) wherein R f complies with formula (a) as defined above and A is a straight or branched C 1 -C 4 perfluoroalkyl group wherein one fluorine atom can be substituted by one chlorine atom or one hydrogen atom, with the proviso that, if chlorine is present in group A, it is in a molar amount lower than 2% with respect to the overall amount of end groups with ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide or with a mixture of two or more thereof.
• Mono- and bifunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) in which R 1 is C 1 -C 4 -straight or branched alkyl can be obtained according to known methods by alkylation of the corresponding mono- and bifunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) in which R 1 is hydrogen.
• Mono- and bifunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) in which R 1 is -C(O)R 2 as defined above can be obtained according to known methods by acylation the corresponding mono- and bifunctional PFPE-PAGs wherein chain R a complies with formula (R a -I) in which R 1 is hydrogen.
• PFPE alcohols of formula (II-A) or (II-B) can be manufactured by chemical reduction of corresponding PFPE carboxylic acids or esters according to several methods known in the art, using reducing agents such as NaBH 4 , or by catalytic hydrogenation, as disclosed, for example, in US 6509509 AUSIMONT SPA 20010705 , US 6573411 AUSIMONT SPA 20021121 , WO WO 2008/122639 SOLVAY SOLEXIS SPA 20081016 .
• Precursors of PFPE carboxylic acids or of PFPE esters can be manufactured according to different methods, e.g.
• this process comprises the following steps: 1) separately providing a mixture [M1], comprising a PFPE alcohol of formula (II) as defined above and a catalytic amount of the corresponding alkoxide (herein after “PFPE-alk”); 2) bringing into contact mixture [M1] with a boric acid triester of the same PFPE alcohol (herein after “PFPE-triBor)” in such an amount that the molar ratio PFPE-alk:PFPE-triBor is at least 1, to obtain a mixture [M2]; 3) contacting mixture [M2] with a catalytic amount of an iodine source to obtain a mixture [M3]; 4) treating mixture [M3] with ethylene oxide, propylene oxide, 1,2-butykene oxide or styrene oxide or a mixture thereof to provide a mixture [M4] containing a PFPE-PAG (I).
• PFPE-alk a boric acid triester of the same PFPE alcohol
• mixture [M1] is typically prepared by adding a base to the PFPE alcohol of formula (II) and by allowing the base to react with the PFPE alcohol and form a catalytic amount of the corresponding PFPE-alk dissolved in the PFPE alcohol.
• the base can be selected from metal hydrides or hydroxides like NaOH, KOH, Ca(OH) 2 and Mg(OH) 2 ; according to a preferred embodiment, the base is KOH.
• the base is used in such an amount to obtain from 1 to 15%, preferably from 2 to 12% of PFPE-alk with respect to the PFPE alcohol.
• the expression “catalytic amount of PFPE-alk” is intended to mean a molar amount ranging from 1 to 15% mol, more preferably from 2 to 12% mol with respect to the PFPE alcohol.
• a metal hydroxide used as base, the reaction is typically promoted by heating and the proceeding of the reaction is checked by monitoring the amount of water evaporated off the reaction mixture.
• a metal hydride used as base, the proceeding of the reaction is checked by monitoring the amount of hydrogen evaporated off the reaction mixture.
• Step 2) can be performed in two different ways.
• a mixture containing a PFPE-triBor and the PFPE alcohol (herein after referred to as mixture [M est ]) is prepared and then brought into contact with mixture [M1].
• [M est ] is prepared by adding boric acid or a boric acid ester (including mono-, di- and tri-alkyl esters), and allowing the reagents to react until completion of the reaction, i.e. until obtainment of the PFPE-triBor in admixture with the PFPE alcohol.
• the esterification reaction is carried out under vacuum and with heating and the completion is checked by monitoring the amount of water (in case boric acid is used) or alcohol (in case an alkyl ester of boric acid is used) evaporated off the reaction mixture.
• the PFPE-triBor is prepared in situ , i.e. by adding to [M1] a boric acid trialkyl ester as defined above; also in this case the reaction is typically carried out under vacuum and with heating and the completion of the reaction is checked in the same way.
• the molar ratio between the PFPE-alk and the PFPE-triBor is at least 1; according to a preferred embodiment, the PFPE-alk is used in excess with respect to PFPE-triBor, i.e. the molar ratio is higher than 1; still more preferably, the molar ratio is of at least 2. Indeed, it has been observed that when a molar ratio of at least 2 is used, the reaction proceeds faster and a higher conversion is achieved.
• Step 3) of the process is typically carried out by adding a catalytic amount of an iodine source, to reaction mixture [M2].
• the iodine source can be selected from one or more alkali- or alkaline-earth metal iodides, such as NaI, KI, CaI 2 , ammonium iodides, such as NH 4 I, elemental iodine and combinations thereof.
• the iodine source is KI.
• a catalytic amount of iodine source is typically an equivalent amount ranging from 0.01 to 5% with respect to the fluoroalcohol.
• Step 4) of the process is typically carried out by adding to mixture [M3] ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide or a mixture thereof in such a stoichiometric amount with respect to PFPE alcohol (II) as to obtain an alkoxylation degree ranging from 4 to 50, preferably from 4 to 15, more preferably from 4 to 10.
• the alkoxylation reaction is typically carried out by adding to mixture [M3] one or more aliquots of ethylene oxide, propylene oxide or a mixture thereof and by monitoring the consumption of the oxide(s) and the formation of the PFPE-PAG.
• ethylene oxide or propylene oxide the reaction is monitored by checking the ethylene oxide pressure in the reactor.
• the reaction is typically carried out under heating at a temperature usually ranging from 90°C to 190°C.
• ethylene oxide is used as alkoxylating agent, the reaction is carried out at temperatures usually ranging from 110° to 160°C.
• the resulting PFPE-PAG can be isolated from mixture [M4] by conventional techniques, including extraction and distillation. Usually, mixture [M4] is cooled down to room temperature and then diluted with a fluorinated solvent, then treated with a water solution of an inorganic base, typically a carbonate, and the organic phase is separated and submitted to distillation.
• a fluorinated solvent typically a carbonate
• fluorinated solvents include, for example, Galden ® PFPEs, hydrofluoroethers (HFEs) including Novec ® HFEs, hydrofluorocarbons (HFCs), like Vertel ® or Fluorinert ® , and fluoroaromatic solvents like hexafluorobenzene and 1,3-hexafluoroxylene.
• the fluorinated solvent is 1,3-hexafluoroxylene.
• PFPE-PAGs according to the present invention are endowed with lubricant properties and they are advantageous in that they are stable under harsh conditions and in that they have a lower coefficient of friction, lower wear and improved performances under extreme pressure conditions with respect to PAGs.
• experiments carried out by the Applicant have demonstrated that PFPE-PAGs of formula (I), in particular those of formula (I-A), are endowed with lower coefficient of friction, lower wear and higher extreme pressure loads with respect to both PAGs having the same molecular weight and PAGs having the same molecular weight as chain R a in the PFPE-PAG.
• Experiments carried out by the Applicant further demonstrated that the PFPE-PAGs of formula (I), in particular those of formula (I-A), are endowed with higher thermal stability than PAGs having the same molecular weight.
• the PFPE-PAGs of the invention can be used as such of in admixture with further ingredients or additives typically used in the manufacture of lubricant compositions. Accordingly, the present invention further relates to a lubricant composition comprising a PFPE-PAG as defined above, in particular a PFPE-PAG of formula (I), in admixture with further lubricants and/or additives selected from those commonly used in lubricant compositions.
• Non-limiting examples of lubricant base oils comprise PFPEs, polyalphaolefins (PAO), PAGs, mineral oils, silicon oils, polyphenyethers, etc.
• Non-limiting examples of additives comprise antirust agents, antioxidants, thermal stabilizers, pour-point depressants, antiwear agents, including those for high pressures, dispersants, tracers, dyestuffs, talc and inorganic fillers.
• dispersants are, for example, surfactants, preferably non-ionic surfactants, more preferably (per)fluoropolyether surfactants and (per)fluoroalkyl surfactants.
• Non-limiting examples of PFPE lubricant base oils such as those disclosed in identified as compounds (1) – (8) EP 2100909 A SOLVAY SOLEXIS SPA 20090916 .
• thickening agents examples include talc, silica, boron nitride, polyureas, alkali or alkali-earth metals terephthalates, calcium and lithium soaps and complexes thereof and PTFE (polytetrafluoroethylene); among them, PTFE is preferred.
• solvents are fluorinated or partially fluorinated solvents, such as Galden ® PFPEs, Novec® HFEs and other organic solvents like methyl-ethyl-ketone, isopropyl alcohol, butylacetate, etc.
• compositions comprising PFPE-PAGs of formula (I) and a PFPE oil may advantageously be in the form of greases (compositions C-1), i.e. the compositions consist of a PFPE oil, a thickening agent and a PFPE-PAG of formula (I) in an amount ranging from 0.1% to 30% wt, preferably from 3% to 10% wt with respect to the weight of the composition.
• compositions show significantly lower wear values than greases that do not contain PFPE-PAGs.
• the PFPE-PAGs of the invention can act as anti-wear additives for lubricant compositions in the form of greases.
• a preferred example of lubricant base oil to be mixed with the PFPE-PAGs of the invention is represented by PAGs.
• experiments carried out by the Applicant showed that the PFPE-PAGs of formula (I) according to the present invention, in particular PFPE-PAGs of formula (I-A), are able to dissolve PAGs.
• the present invention further relates to a lubrication method comprising applying a PFPE-PAG of formula (I) as defined above in admixture with a PAG, and to lubricant compositions (compositions C-2) comprising, preferably consisting of, a PFPE-PAG of formula (I) as defined above in admixture with a PAG and, optionally, one or more additives.
• compositions C-2 comprise, preferably consist of, a PFPE-PAG of formula (I) as defined above and a PAG in a weight amount ranging from 5 to 10% with respect to the weight of the composition and, optionally, one or more additives.
• compositions C-2 consisting of: (a1) a PFPE-PAG of formula (I) as defined above and (a2) a PAG, preferably a PEG and, optionally (a3) one or more additives.
• Lubricant compositions C-1 and C-2 can be manufactured according to methods known in the art.
• PFPE-PAGs of referred to in the Examples were synthesised following the process in international patent application filed on December 4 th , 2013 with number EP2013/075476 by Solvay Specialty Polymers Italy S.p.A.
• PEG 2000 and PEG 400 were purchased from Aldrich ® and were used as such.
• Friction and wear properties were determined according to the ASTM D6425 “Standard Test Method for Measuring Friction and Wear Properties of Extreme Pressure (EP) Lubricating Oils Using SRV Test Machine” using a ball-on-disk configuration with a pre-load at 50N for 30’’, a load of 300 N for 2 hours, with a frequency of 50 Hz and a stroke of 1 mm.
• the pour point of the analyzed samples was determined according to the ASTM D97 “Standard Test Method for Pour Point of Petroleum Products”.
• Polyethylenglycol PEG 2000 which is a white solid at room temperature having an average molecule weight of 2000, was heated above its melting point ( ⁇ 50°C) in order to measure the kinematic viscosity. At 100°C the kinematic viscosity was equal to 43.04 cSt.
• a SRV test was carried out at 100°C, in double, with a kinematic viscosity of the product corresponding to 43.04 cSt, under the same isoviscous conditions as Example 1. After the test, the average coefficient of friction was 0.20 ⁇ 0.02 and the measure wear-on-the-ball was 1.5 ⁇ 0.1 mm.
• Examples 1, 2 and 3 above show that the PFPE-PAG is endowed with lower coefficient of friction, lower wear and good viscosity index with respect to: - both a PEG having the same molecular weight as the PFPE-PAG of Example 1 (Comparative example 2) and - a PEG having the same molecular weight as the PAG moieties in the PFPE-PAG of Example 1 (Comparative example 3).
• the product is a transparent liquid at room temperature having a pour point of -38°C.
• a SRV test was carried out at 50°C, in double, with a kinematic viscosity of the product corresponding to 63 cSt. After the test the average coefficient of friction was 0.15 ⁇ 0.004 and the measured wear-on-the-ball was 1.1 ⁇ 0.1 mm.
• a thermal stability test on the PFPE-PAG of Example 1 was performed by means TGA in air (10°C/min). At 250°C a weight loss of 6% was observed, while at 300°C the corresponding value was 19% (see Figure 1).
• Examples 7 and Example 8 show that the PFPE-PAGs of the invention have improved thermal stability than PAGs having the same molecular weight.
• a perfluorinated grease was prepared by adding a commercial PFPE, Fomblin ® M30, to the powder of PTFE, in order to reach a cone penetration value of 277 mm/10’.
• the grease prepared in the Example 9 was added with 5% by weight of the PFPE-PAG of Example 1 and was subjected to the 4-ball wear test following the procedure described above.
• the wear observed on the ball after the test was 0.80 mm + 0.05 mm.
• Example 9 and 10 show that the PFPE-PAGs of the invention are able to act as antiwear additive for perfluorinated greases.
• a commercial base oil (without additives) consisting of polypropyleneglycol monobutylether, having an average molecular weight M n of 1,400 g/mol was analysed.
• a SRV test was carried out, in double, at 70°C, with a kinematic viscosity of the product corresponding to 44 cSt. After the test, the average coefficient of friction was 0.22 ⁇ 0.001 and the measured wear on the ball was 1.6 ⁇ 0.1 mm.
• the base oil was analysed under extreme pressure conditions according to the ASTM D7421, under the same operative conditions as in Example 11: The results showed that seizure occurred at a load of 1000 N.
• Example 11 shows that the presence of PFPE sequences in the PFPE-GAG imparts lubrication properties to the PAG base oil, low coefficient of friction, low wear and significantly improved extreme pressure properties.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2015
  • 2015-07-29 WO PCT/EP2015/067354 patent/WO2016020232A1/en active Application Filing
  • 2015-07-29 US US15/501,820 patent/US20170240839A1/en not_active Abandoned
  • 2015-07-29 EP EP15750276.6A patent/EP3177701B1/de not_active Not-in-force
  • 2015-07-29 CN CN201580054088.8A patent/CN107109283A/zh active Pending
  • 2015-07-29 JP JP2017506335A patent/JP2017523292A/ja active Pending

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