U.S. patent application number 14/779474 was filed with the patent office on 2016-02-18 for modified hydrogen-based lubricants.
The applicant listed for this patent is SOLVAY SPECIALTY POLYMERS ITALY S.P.A.. Invention is credited to Marco AVATANEO, Evgeny DENISOV, Giuseppe MARCHIONNI, Claudio Adolfo Pietro TONELLI, Davide VICINO.
Application Number | 20160046887 14/779474 |
Document ID | / |
Family ID | 48092820 |
Filed Date | 2016-02-18 |
United States Patent
Application |
20160046887 |
Kind Code |
A1 |
AVATANEO; Marco ; et
al. |
February 18, 2016 |
MODIFIED HYDROGEN-BASED LUBRICANTS
Abstract
The present invention related to a process for the manufacture
of hydrogen-based lubricants modified with per(halo)fluorinated
aromatic compounds, to the modified lubricants thereby obtained and
to the use of the modified lubricants for the preparation of
lubricant compositions.
Inventors: |
AVATANEO; Marco; (Senago,
IT) ; DENISOV; Evgeny; (Milan, IT) ; VICINO;
Davide; (Caronno Pertusella, IT) ; TONELLI; Claudio
Adolfo Pietro; (Paderno D'adda, IT) ; MARCHIONNI;
Giuseppe; (Milano, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SOLVAY SPECIALTY POLYMERS ITALY S.P.A. |
Bollate (MILANO) |
|
IT |
|
|
Family ID: |
48092820 |
Appl. No.: |
14/779474 |
Filed: |
April 10, 2014 |
PCT Filed: |
April 10, 2014 |
PCT NO: |
PCT/EP2014/057233 |
371 Date: |
September 23, 2015 |
Current U.S.
Class: |
508/577 ;
508/588 |
Current CPC
Class: |
C10M 2211/0445 20130101;
C10M 2211/0206 20130101; C10N 2040/06 20130101; C10N 2040/30
20130101; C10M 2211/0245 20130101; C10M 2211/0406 20130101; C10N
2030/06 20130101; C10M 109/02 20130101; C10N 2040/25 20130101; C10M
107/38 20130101; C10N 2030/10 20130101; C10M 169/042 20130101; C10N
2020/02 20130101; C10N 2040/04 20130101; C10N 2040/135 20200501;
C10N 2040/252 20200501; C10N 2030/08 20130101 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 2013 |
EP |
13163768.8 |
Claims
1. A process for the addition of a hydrogen-based lubricant to a
per(halo)fluorinated aromatic compound, said process comprising
reacting, via a radical reaction, a hydrogen-based lubricant
(R.sub.H) with a per(halo)fluorinated aromatic compound (F) to
provide a compound (A) comprising at least one per(halo)fluorinated
cyclic group (F') having at least one lubricant chain (R.sub.HC)
bound thereto, said group (F') optionally containing conjugated or
non-conjugated double bonds.
2. The process according to claim 1, wherein lubricant (R.sub.H) is
one or more lubricant having a viscosity ranging from 2 to
1,000,000 cSt and containing straight or branched hydrocarbon
moieties.
3. The process according to claim 2, wherein lubricant (R.sub.H) is
in the liquid or in the semi-solid form at room temperature.
4. The process according to claim 3, wherein lubricant (R.sub.H) is
in the liquid form and is selected from one or more mineral oils of
hydrocarbon type, animal or vegetable oils, synthetic oils,
polyalphaolefins (PAOs), dibasic acid esters, polyol esters,
phosphate esters, polyesters, alkylated naphthalenes, polyphenyl
ethers, polybutenes, multiply-alkylated cyclopentanes, silane
hydrocarbons, siloxanes and polyalkylene glycols.
5. The process according to claim 4, wherein oil (R.sub.H) is a
mineral oil of hydrocarbon type or a polyalphaolefin.
6. The process according to claim 1, wherein the radical reaction
is initiated by contacting lubricant (R.sub.H) and compound (F)
with organic or inorganic peroxides, redox systems, ozone, hydrogen
peroxide or by thermal or photochemical decomposition of lubricant
(R.sub.H).
7. The process according to claim 6, wherein the organic peroxide
is benzoyl peroxide or di-ter-butyl peroxide.
8. The process according to claim 1, which is carried out in the
absence of solvents.
9. The process according to claim 1, wherein compound (F) is
selected from perfluorobenzene, perfluorobiphenyl,
perfluoronaphthalene, perfluoroanthracene, perfluoropyridine,
perfluorotoluene and derivatives thereof comprising one or more
perfluorinated substituent(s).
10. The process according to claim 9, wherein compound (F) is
selected from perfluorobenzene and perfluorobiphenyl.
11. An addition compound (A) comprising at least one
per(halo)fluorinated cyclic group (F') having at least one
hydrogen-based lubricant chain (R.sub.HC) bound thereto, said group
(F') optionally containing conjugated or non-conjugated double
bonds.
12. A method for lubricating an item, the method comprising
contacting the item with compound (A) as claimed in claim 11.
13. A method for manufacturing a lubricant composition comprising
adding compound (A) as claimed in claim 11 to at least one further
ingredient or additive.
14. A lubricant composition comprising compound (A) as claimed in
claim 11 in admixture with at least one further ingredient or
additive.
Description
[0001] This application claims priority to European patent
application no. 13163768.8--filed on Apr. 15, 2013--the whole
content of this application being incorporated herein by reference
for all purposes.
TECHNICAL FIELD
[0002] The present invention relates to modified lubricants, in
particular to modified hydrogen-based lubricants.
BACKGROUND ART
[0003] It is known that certain hydrogen-based lubricants of
natural or synthetic origin, in particular certain lubricant oils,
are endowed with remarkable lubricant properties and are available
on the market at reasonable costs. Examples of hydrogen-based
lubricant oils comprise mineral oils of hydrocarbon type, animal
and vegetal hydrogenated oils, synthetic hydrogenated oils
including polyalphaolefins (PAOs), dibasic acid esters, polyol
esters, phosphate esters, polyesters, alkylated naphthalenes,
polyphenyl ethers, polybutenes, multiply-alkylated cyclopentanes,
silane hydrocarbons, siloxanes and polyalkylene glycols.
[0004] Such oils are able to form an even, cohesive film on the
substrate to be lubrified; cohesiveness is a desirable key property
in any lubricant application, especially in automotive
applications. However, they possess low thermal and
thermo-oxidative stability and low chemical inertness and,
therefore, they are not suitable for lubricant applications wherein
high temperatures are reached and wherein reactive species form
which may lead to degradation of the lubricant film.
[0005] On the contrary, (per)fluoropolyether (PFPE) lubricants,
i.e. lubricants comprising a perfluorooxyalkylene chain, that is to
say a chain comprising recurring units having at least one ether
bond and at least one fluorocarbon moiety, are endowed with high
thermal and chemical resistance, so they are useful in cases of
applications characterized by harsh conditions (very high
temperatures, presence of oxygen, use of aggressive chemicals and
radiations, etc.) and the risk of degradation of the lubricant film
is high. Nevertheless, PFPE lubricants are less performing than
hydrocarbon oils in terms of adhesion properties and film strength,
they are expensive and also outperforming from the standpoint of
thermal stability in applications wherein conditions are not harsh,
i.e. wherein the lubricant temperature does not exceed 150.degree.
C.
[0006] It would therefore be desirable to provide lubricants having
intermediate properties between hydrogen-based lubricants and PFPE
lubricants. In particular, it would be desirable to provide
hydrogen-based lubricants with higher thermal and chemical
stability, higher resistance to wear and friction than PFPE
lubricants and which are, at the same time, less expensive.
[0007] It is known from KOBRINA, L. S. Some peculiarities of
radical reactions of polyfluoroaromatic compounds. Journal of
Fluorine Chemistry. 1989, vol. 142, no. 3, p. 301-344. that
polyfluorinated aromatic compounds undergo addition reactions with
(fluoro)organic radicals; this paper discloses in particular the
thermal decomposition of pentafluorobenzoyl peroxide in
hexafluorobenzene to provide dimers and addition complexes. The
paper also reports on the reactions of octafluorotoluene,
octafluoronaphthalene and decafluorobiphenyl in the presence of
benzoyl peroxide as radical source and on the reactions of
hexafluorobenzene with alkyl radicals differing in polarity and
steric requirements, namely methyl and cyclohexyl radicals
generated from tert-butyl peroxide. These reactions are further
discussed in KOBRINA, L. S. Radical reactions of polyfluoroarenes.
Fluorine notes. 2012, vol. 2, no. 81.
[0008] Addition reactions of certain organic radicals on
polyfluoroaromatic compounds are also disclosed in BROOKE, G. M.
The preparation of polyfluoroaromatic and heteroaromatic compounds.
Journal of Fluorine Chemistry. 1997, vol. 86, no. 1, p. 1-76.
Nevertheless, these last two prior art documents are concerned only
with the addition of low molecular weight (per)fluoroalkyl or
(per)fluoroalkanoyl peroxides to certain fluoroaromatic compounds;
furthermore, the addition reaction was studied only for
mechanicistic purposes.
[0009] EP 2100909 A (SOLVAY SOLEXIS S.P.A.) 16, Sep. 2009 discloses
a process for the addition of PFPE peroxides onto
per(halo)fluorinated aromatic compounds to provide addition
compounds comprising at least one perfluorinated non-aromatic
cyclic group having at least two substituents comprising a PFPE
chain and, optionally, conjugated or non-conjugated double bonds.
The addition compounds are suitable as additives for
(per)fluorinated fluids and for (per)fluorinated lubricants or as
base materials for the manufacture of gum and/or graft polymer
compositions.
[0010] None of the above prior art documents teaches the reaction
of perfluorinated aromatic compounds with hydrogen-based
lubricants.
[0011] WO 2012/007374 (SOLVAY SOLEXIS S.P.A.) 19, Jan. 2012
discloses a block copolymer comprising one or more PFPE segments,
one or more polyalkylene segments and, optionally, at least one
per(halo)fluorinated non-aromatic cyclic moiety having chemically
bound thereto at least two sp3 hybridized carbon atoms of PFPE
segments and, optionally, conjugated or non-conjugated double
bonds. This document does not disclose addition compounds obtained
by radical addition of a hydrocarbon oil to a per(halo)fluorinated
cyclic compound.
[0012] U.S. Pat. No. 3,720,646 (MONTEDISON S.P.A.) 13, Mar. 1973
discloses the reaction product of a PFPE with an optionally
halogenated quinone compound; also this document does not disclose
addition compounds obtained by radical addition of a hydrocarbon
oil, like a polyalphaolefin or a mineral oil, to a
per(halo)fluorinated cyclic compound.
[0013] It has now been found that improved hydrogen-based
lubricants can be obtained by modifying them with perfluoroaromatic
compounds.
SUMMARY OF INVENTION
[0014] Accordingly, the present invention relates to a process for
the addition of a hydrogen-based lubricant to a
per(halo)fluorinated aromatic compound, said process comprising the
radical reaction of a hydrogen-based lubricant [lubricant
(R.sub.H)] with a per(halo)fluorinated aromatic compound [compound
(F)] to provide a compound [compound (A)] comprising at least one
per(halo)fluorinated cyclic group [group (F')] having at least one
lubricant chain [chain (R.sub.HC)] bound thereto, said group (F')
optionally containing conjugated or non-conjugated double
bonds.
[0015] Compounds [A] obtainable according to the present invention
will be herein otherwise referred to as "modified lubricants".
[0016] For the purposes of the present invention, the expression
"hydrogen-based lubricants" is intended to denote one or more
lubricants (either natural or synthetic or semi-synthetic) whose
viscosity ranges from 2 to 1,000,000 cSt, preferably from 2 to
3,000 cSt, and containing straight or branched hydrocarbon
moieties. Thus, hydrogen-based lubricants include those which at
room temperature (25.degree. C.) are in the liquid form, namely
lubricant oils, and those which at room temperature are in the
semi-solid form like lubricant waxes or greases. Hydrogen-based
lubricants suitable for the purposes of the present inventions are
lubricant oils including mineral oils of hydrocarbon type, animal
or vegetable oils, synthetic oils like polyalphaolefins (PAOs),
dibasic acid esters, polyol esters, phosphate esters, polyesters,
alkylated naphthalenes, polyphenyl ethers, polybutenes,
multiply-alkylated cyclopentanes, silane hydrocarbons, siloxanes
and polyalkylene glycols. Preferably, the hydrogen-based lubricant
is a mineral oil of hydrocarbon type or a polyalphaolefin.
[0017] For the sake of clarity, the expression "lubricant(s)
(R.sub.H)" is intended to mean "hydrogen-based lubricant
lubricant(s) (R.sub.H)".
[0018] Without wishing to be bound to theory, the process typically
proceeds via extraction of hydrogen from lubricant (R.sub.H) and
formation of radical lubricant chain (R.sub.HC.), which adds to
compound (F) to form radical species (R.sub.HC--F'.) which reacts
with another radical (R.sub.HC.), giving rise to disubstituted
addition compounds (A) of the type R.sub.HC--F'--R.sub.HC, wherein
lubricant chains (R.sub.CH) are linked to spa hybridized carbons of
group (F'). Radicals (R.sub.HC--F.) can also react together to form
addition compounds of the type R.sub.HC--F'--F'--R.sub.HC; some
radicals (R.sub.HC--F.) may also combine with a hydrogen atom,
thereby forming mono-substituted addition compounds (A) of the type
R.sub.HC--F'--H, which may undergo re-aromatization to form
compounds (A) wherein (F') is an aromatic cyclic group and wherein
chain (R.sub.CH) is linked to a sp.sup.2 hybridized carbon of group
(F').
[0019] The choice of the per(halo)fluorinated aromatic compound
[compound (F)] is not particularly limited, provided that this
compound is aromatic and that is per(halo)fluorinated, that is to
say that it is free from hydrogen atoms and comprises at least one
fluorine atom.
[0020] For the avoidance of doubt, the term "aromatic compound" is
hereby intended to denote a cyclic structure having a delocalized
conjugated .pi. system with a number of .pi. delocalized electrons
fulfilling the Huckel's rule (number of .pi. electrons equal to
(4n+2), with n being an integer).
[0021] Per(halo)fluorinated aromatic compound (F) can be monocyclic
or polycyclic and can comprise one or more than one aromatic ring.
Should it comprise more than one aromatic ring, these aromatic
rings can be condensed or not condensed. Compound (F) can be a
heteroaromatic compound, comprising one or more heteroatoms (e. g.
O, S, N) in the ring and can be substituted or not substituted.
[0022] Preferably, compound (F) is perfluorinated, that is to say
that all its free valences are saturated with fluorine atoms.
[0023] Non limitative examples of compounds (F) which are suitable
for the purposes of the present invention are notably
perfluorobenzene, perfluorobiphenyl, perfluoronaphthalene,
perfluoroanthracene, perfluoropyridine, perfluorotoluene and
derivatives thereof comprising one or more perfluorinated
substituent(s). Preferred examples of compounds (F) are
perfluorobenzene (hexafluorobenzene) and
perfluorobiphenyl(decafluorobiphenyl).
[0024] The radical reaction according to the present invention can
be initiated by contacting lubricant (R.sub.H) and compound (F)
with organic or inorganic peroxides, with redox systems, with ozone
or hydrogen peroxide; it can also be initiated by thermal or
photochemical decomposition of lubricant (R.sub.H).
[0025] Organic peroxides include, for example, diacyl peroxide,
peroxy esters, peroxidicarbonates, dialkyl peroxides, ketone
peroxides, peroxy ketals, hydroperoxides, which are soluble in the
aforementioned hydrogen-based oils; more preferably, the organic
peroxide is selected from benzoyl peroxide and di-ter-butyl
peroxide (DTBP).
[0026] Inorganic peroxides include, for example, ammonium
peroxydisulfate, potassium peroxydisulfate, sodium peroxydisulfate
and potassium monopersulfate.
[0027] Examples of redox systems include those based on Fe(II) ions
in combination with hydrogen peroxide, organic peroxides (including
alkyl peroxides, hydroxyperoxides, acyl peroxides),
peroxydisulphates, peroxydiphosphates; Cr (II), V (II), Ti (III),
Co (II) and Cu (I) ions can also be employed instead of Fe(II) ions
in many of these systems. Redox systems based on organic alcohols
and transition metals chosen among Ce (IV), V (V), Cr (VI) and Mn
(III) can also be employed.
[0028] Thermal decomposition of lubricant (R.sub.H) can be achieved
by heating a mixture of lubricant (R.sub.H) and compound (F) at
such a temperature as to generate radicals (R.sub.HC.); this
temperature depends on the specific lubricant (R.sub.H) to be
modified and can be determined by the person skilled in the art on
a case-by-case basis according to known methods. In any case, this
temperature is generally higher than 150.degree. C., typically
higher than 200.degree. C.
[0029] Photochemical decomposition of lubricant (R.sub.H) can be
accomplished by submitting a mixture of lubricant (R.sub.H) and
compound (F) to a radiation source, including UV-rays, X-rays and
.gamma.-rays sources. Photochemical decomposition by exposure to
UV-rays is typically carried out in the presence of a
photo-initiator, including, for example, benzoin ethers, benzyl
ketals, .alpha.-dialkoxy-acetophenones,
.alpha.-hydroxy-alkyl-phenones, .alpha.-amino-alkyl-phenones,
acylphosphine oxides, benzophenones, benzoamines, thio-xanthones,
thio-amines, titanocenes. However, the use of photo-initiators can
be avoided if the hydrocarbon oil contains functional groups able
to generate radicals upon exposure to UV rays; examples of such
functional groups are carbonyl groups.
[0030] The process of the invention is preferably carried out
without solvents; nevertheless, solvents can also be employed,
especially if lubricant (R.sub.H) is highly viscous, in particular
if viscosity is higher than 3,000 cSt, in order to bring lubricant
(R.sub.H) into intimate contact with compound (F). The solvent will
be selected by the person skilled in the art on a case-by-case
basis, according to the specific lubricant (R.sub.H) and compound
(F), in such a way as it does not generate radicals that might
interfere with the reaction between lubricant (R.sub.H) and
compound (F). Examples of suitable solvents are organic solvents
like alkanes, ketons, esters and aromatics solvents, optionally
chlorinated or fluorinated.
[0031] The weight ratio between lubricant (R.sub.H) and compound
(F) typically ranges from 0.01 to 1.000, more preferably between
0.05 and 100 and even more preferably between 0.1 and 10.
[0032] The reaction is generally carried out under magnetic or
mechanical stirring and under inert atmosphere, for example under
nitrogen atmosphere.
[0033] If the radical reaction is initiated by contacting lubricant
(R.sub.H) and compound (F) with organic or inorganic peroxides, the
temperature is typically set in such a way as to range from
20.degree. C. to 250.degree. C., preferably from 50.degree. to
200.degree. C. The reaction temperature will be established by the
person skilled in the art on the basis of the decomposition
kinetics of the peroxide. Optionally, in order to keep the
concentration of lubricant radicals (R.sub.HC.) within a defined
range over the process, the temperature can be increased, either
linearly or step-by-step, with time.
[0034] If the radical reaction is initiated by contacting lubricant
(R.sub.H) and compound (F) with a redox system, it is typically
performed at a temperature ranging from -40.degree. C. to
250.degree. C., preferably from 20.degree. C. to 100.degree. C.
[0035] If the radical reaction is initiated by photochemical
decomposition of lubricant (R.sub.H) with photo-initiators or by
radiation-induced decomposition of lubricant (R.sub.H), it is
typically performed at a temperature ranging from -100.degree. C.
to 200.degree. C., preferably from -40.degree. C. to 120.degree.
C.
[0036] If the radical reaction is initiated by thermal
decomposition of lubricant (R.sub.H), it is typically performed at
a temperature ranging from 100.degree. C. to 350.degree. C.,
preferably from 150.degree. C. to 300.degree. C.
[0037] The reaction can be performed either in batch or in
semi-batch or in a continuous stirred-tank reactor.
[0038] At the end the reaction, the excess of compound (F),
residues of any organic initiators and any undesired by-products
are removed by using techniques known in the art for, example by
distillation or solvent extraction. Filtration can also be carried
out afterwards to remove any solid impurities. Distillation is
typically carried out under reduced pressure at a temperature lower
than that at which thermal decomposition of the lubricant begins.
As an alternative, water-vapour phase distillation can be used.
Extraction is typically carried out with halogenated solvents which
solubilize the excess of compound (F), but not compounds (A); among
halogenated solvents, (per)fluoropolyether (PFPE) solvents are
preferred.
[0039] Typically, the process of the invention allows obtaining
compounds (A) wherein the weight percentage of per(halo)fluorinated
cyclic group [group (F')], preferably perfluorinated cyclic group,
with respect to the weight of compound (A) ranges from 1 to 15%,
preferably from 2 to 12%.
[0040] A further object of the present invention is a compound
[compound (A)] comprising at least one per(halo)fluorinated cyclic
group [group (F')] having at least one lubricant (R.sub.H) chain
[chain R.sub.HC] bound thereto, said group (F') optionally
containing conjugated or non-conjugated double bonds. Compounds (A)
are obtainable through the process of the invention.
[0041] For the sake of clarity, in the expression "lubricant
(R.sub.H) chain [chain R.sub.HC]", "lubricant (R.sub.H)" means a
"hydrogen-based lubricant (R.sub.H)" as defined above.
[0042] In compounds (A), the at least one lubricant chain can be
bound to an sp.sup.2 hybridized carbon of group (F') (when
re-aromatization occurs in the process) or to an sp.sup.3
hybridized carbon of group (F'). Typically, compounds (A) comprise
at least two lubricant chains, each chain being bound to at least
one sp.sup.3 hybridized carbon atom of group (F').
[0043] Typically, in compounds (A), the weight percentage of
per(halo)fluorinated cyclic group [group (F')], preferably
perfluorinated cyclic group, with respect to the weight of compound
(A) ranges from 1 to 15%, preferably from 2 to 12%.
[0044] According to a preferred embodiment of the invention,
compounds (A) comply with formula (I) below:
##STR00001##
wherein: [0045] R.sub.HC and R'.sub.HC, equal to or different from
one another, each represent a lubricant chain (R.sub.HC) bound to a
sp.sup.3 hybridized carbon atom: [0046] X.sub.f and X.sub.f', equal
to or different from one another, are selected from halogen and
C.sub.1-C.sub.12 per(halo)fluorocarbon substituents, preferably
among --F and C.sub.1-C.sub.12 perfluoroalkyl or perfluoroaryl
groups; [0047] NA represents a per(halo)fluorinated non-aromatic
cyclic moiety [moiety (NA)] optionally condensed with additional
aromatic or non-aromatic cycles, optionally having one or more
conjugated or non-conjugated double bond(s), optionally having one
or more per(halo)fluoro substituents and wherein said cyclic moiety
comprises the two sp.sup.3 hybridized carbon bearing R.sub.HC and
R'.sub.HC chains.
[0048] Non limitative examples of structures encompassed by the
above general formula of compound (A) as above detailed are notably
the followings:
##STR00002##
wherein R.sub.HC, R'.sub.HC are lubricant chains as defined above
and W.sub.f is a fluorine atom or a C.sub.1-C.sub.6 perfluorocarbon
group.
[0049] According to a preferred embodiment of the invention, in
compounds (A), (R.sub.CH) represents a lubricant chain of a mineral
oil or of a polyalphaolefin. According to a further preferred
embodiment, compounds (A) comprise at least one lubricant chain
selected from a mineral oil and a polyalphaolefin and at least one
perfluorinated cyclohexyl or bicyclohexyl group (F') optionally
containing conjugated or non-conjugated double bonds.
[0050] Compounds (A) according to the present invention are used as
lubricants, in particular, as lubricants for internal combustion
engine oils (including car engines, tractor engines, gas engines,
marine diesel engine), gears, ballistics systems, compressors (for
example screw compressor, roots compressor, turbo compressor,
compressor for the production of compressed air), refrigerators,
turbines, hydroelectric plants, and wind-mills. Thus, the present
invention also relates to a lubrication method comprising using
compounds (A).
[0051] Although compounds (A) are preferably used as such, they can
also be mixed with further ingredients and additives to form
lubricant compositions. Thus, the present invention further
comprises a method of manufacturing lubricant compositions
comprising using compounds (A), as well as lubricant compositions
containing one or more compounds (A) in admixture with further
ingredients and additives. Examples of further ingredients are
unmodified hydrocarbon oils; however, (per)fluoropolyether oils
(PFPE oils) can also be used. Examples of suitable PFPE oils are
those identified as compounds (1)-(8) in the above-cited European
patent application EP2100909. Metal detergents, ashless
dispersants, oxidation inhibitors, rust inhibitors (otherwise
referred to as anti-rust agents), emulsifiers, extreme pressure
agents, friction modifiers, viscosity index improvers, pour point
depressants and foam inhibitors con also be used as further
ingredients/additives to be added to the modified lubricants of the
invention to prepare lubricant compositions. Suitable further
ingredients and additives and methods for the manufacture of
lubricant compositions will be chosen by the person skilled person
according to the compound (A) to be formulated and according to the
specific intended use in view of the common general knowledge, for
example according to Lubricants and lubrication. 2nd edition.
Edited by MANG, Theo, et al. Weinheim: Wiley-VCH Verlag GmbH,
2007.
[0052] Lubricant compositions containing compounds (A) can be, for
example, in the form of oil-in water emulsions, oil-in-oil
emulsions, greases, pastes, suspensions or powders; the form of the
composition will be chosen by the skilled person according to the
specific intended use.
[0053] The present invention is advantageous in several aspects.
The toxicological risk of the process of the invention is
relatively low, since, unlike non-fluorinated aromatic compounds,
perfluorinated aromatic compounds are generally not harmful.
Furthermore, they are usually soluble in hydrocarbon oils, so the
use of solvents can be avoided; this allows reducing not only
toxicological risks, but also production costs. Due to the superior
oxidative stability of compounds (A), maintenance and service costs
are reduced in comparison with those of the corresponding
non-modified lubricants.
[0054] The invention is illustrated in greater detail in the
following Experimental Section.
[0055] Should the disclosure of any patents, patent applications,
and publications which are incorporated herein by reference
conflict with the description of the present application to the
extent that it may render a term unclear, the present description
shall take precedence
EXPERIMENTAL SECTION
Materials and Methods
[0056] Mineral oil (Yubase.RTM. IV) was purchased from Fuchs
Lubricants, polyalphaolefin 400/40 (PAO 400/40), polyalphaolefin
65/40 (PAO 65/40) were purchased from Kluber Lubrication.
[0057] Decafluorobiphenyl(perfluorobiphenyl) and hexafluorobenzene
(perfluorobenzene) were purchased from Sigma-Aldrich.RTM..
[0058] Benzoyl peroxide (70% wt in water) and di-tert-butyl
peroxide (DTBP) were purchased from Sigma-Aldrich.RTM..
[0059] All reagents were used as received.
[0060] .sup.19F-NMR spectra were recorded on a Varian Mercury 300
MHz spectrometer; samples: 10% wt solutions in n-hexane.
[0061] Dynamic thermogravimetric analyses were carried out with a
Perkin Elmer.RTM. PYRIS 1 TGA apparatus.
[0062] FT-IR spectra were recorded on a Nicolet Avatar.RTM. FT-IR
spectrometer. Tribological tests were carried out with an
Optimal.RTM. SRV III test machine. In the following examples, the
expressions "hexafluorobenzene moieties" and "decafluorobiphenyl
moieties" are intended to comprise any cyclic group, optionally
containing conjugated or non-conjugated double bonds, deriving from
the addition of the selected lubricant to hexafluorobenzene and
decafluorobiphenyl respectively.
EXAMPLES
Example 1
Reaction of polyalphaolefin 400/40 (PAO 400/40) with
decafluorobiphenyl
[0063] 40 g PAO 400/40, 72 g decafluorobiphenyl (216 mmol) and 18 g
benzoyl peroxide (52 mmol) were placed in a 250 ml glass flask
equipped with magnetic stirrer, under nitrogen atmosphere.
[0064] The mixture was heated to 80.degree. C. until it turned to a
homogeneous solution, which was then stirred for 4.5 hours at 300
rpm following a heating ramp from 80.degree. C. to 120.degree. C.
with steps of 5.degree. C. every 30 minutes.
[0065] At the end, the reaction mixture was distilled under vacuum
(10.sup.-2 mbar) up to 230.degree. C. to remove the excess of
decafluorobiphenyl (bp=208.degree. C.) and by-products (mainly
benzoic acid) to obtain 45.3 modified PAO. .sup.19F-NMR analysis
showed the presence of 8.5% by weight of decafluorobiphenyl
moieties.
Example 1bis
Reaction of polyalphaolefin 400/40 (PAO 400/40) with
decafluorobiphenyl
[0066] The same procedure as in example 1 was followed, with the
difference that 16 g decafluorobiphenyl (48 mmol) and 5 g benzoyl
peroxide (15 mmol) were used. 41.2 g modified PAO were obtained and
.sup.19F-NMR analysis confirmed the presence of 2% wt of
decafluorobiphenyl moieties.
Example 2
Reaction of polyalphaolefin 65/40 (PAO 65/40) with
decafluorobiphenyl
[0067] The same procedure as in example 1 was followed, with the
difference that 40 g PAO 65/40 instead of 40 g PAO 400/40 was used.
47.98 g modified PAO were recovered and .sup.19F-NMR analysis
confirmed the presence of 10.2% wt of decafluorobiphenyl
moieties.
Example 3
Reaction of polyalphaolefin 400/40 (PAO 400/40) with
decafluorobiphenyl
[0068] A 45 ml stainless steel autoclave, equipped with magnetic
stirrer, was charged with 5 g polyalphaolefin (PAO 400/40), 9.2 g
decafluorobiphenyl and 0.98 g di-tert-butyl peroxide (DTBP). The
autoclave was immersed in liquid nitrogen and three vacuum-nitrogen
cycles were applied. At the end, the autoclave was heated to room
temperature and pressurized under 2 bars nitrogen.
[0069] The reaction was conducted at 130.degree. C. for 4.5 hours.
At the end, the reaction mixture was cooled to room temperature and
the excess of decafluorobiphenyl and by-products were removed by
distillation at 230.degree. C. at 10.sup.-2 mbar to afford 5.72 g
modified PAO. .sup.19F-NMR analysis confirmed the presence of 7.5%
by weight of decafluorobiphenyl moieties.
Example 4
Reaction of a Mineral Oil with Decafluorobiphenyl
[0070] 10 g mineral oil Yubase.RTM. IV, 18 g decafluorobiphenyl (53
mmol) and 4.6 g of benzoyl peroxide (13 mmol) were placed in a 100
ml glass flask equipped with a magnetic stirrer, under nitrogen
atmosphere.
[0071] The mixture was heated to 80.degree. C. until it turned to a
homogeneous solution, which was then stirred for 4.5 hours at 300
rpm following a heating ramp from 80.degree. C. to 120.degree. C.
with steps of 5.degree. C. every 30 minutes.
[0072] At the end, the reaction mixture was distilled under vacuum
(10.sup.-2 mbar) up to 230.degree. C. to remove the excess of
decafluorobiphenyl (bp=208.degree. C.) and by-products (mainly
benzoic acid) to obtain 9.0 g modified oil. 19F-NMR analysis showed
the presence of 9.5% by weight of decafluorobiphenyl moieties.
Example 5
Reaction of a Mineral Oil with Hexafluorobenzene
[0073] 10 g mineral oil Yubase.RTM. IV, 10 g hexafluorobenzene (54
mmol) and 4.6 g benzoyl peroxide (13 mmol) were placed in a 100 ml
glass flask equipped with magnetic stirrer and condenser.
[0074] The mixture was heated to 80.degree. C. at reflux under
nitrogen atmosphere and then stirred for 8 hours at 80.degree. C.
at 300 rpm.
[0075] The reaction mixture was distilled under the same conditions
as in Example 1, to afford 8.98 g modified oil. .sup.19F-NMR
confirmed the presence of 3.1% by weight of hexafluorobenzene
moieties.
Example 6
Reaction of polyalphaolefin 65/40 (PAO 65/40) with
hexafluorobenzene
[0076] A 45 ml stainless steel autoclave, supplied with magnetic
stirrer, was charged with 5 g polyalphaolefin PAO 65/40 (PAO
65/40), 5 g hexafluorobenzene and 2.3 g benzoyl peroxide. The
autoclave was immersed in liquid nitrogen and three cycle of
vacuum-nitrogen were applied. At the end, the autoclave was heated
to room temperature and pressurized with 2 bars nitrogen and the
reaction was conducted from 80 to 120.degree. C., with a heating
ramp of 5.degree. C. every 30 minutes.
[0077] At the end, the reaction mixture was cooled to room
temperature and the excess of hexafluorobenzene and by-products
were removed by distillation at 150.degree. C. at 10.sup.-2 mbar,
to afford 4.91 g modified PAO. .sup.19F-NMR confirmed the presence
of 5.7% by weight hexafluorobenzene moieties.
Example 7
Reaction of polyalphaolefin 65/40 with hexafluorobenzene
[0078] The same procedure as in example 6 was followed, with the
difference that 1.02 g DTBP was used and that after pressurizing
the autoclave with 2 bars nitrogen, the reaction was conducted at
130.degree. C. for 6 hours. After distillation of the excess of
hexafluorobenzene and by-products, 5.29 g modified PAO was
recovered. .sup.19F-NMR analysis confirmed the presence of 8.9% by
weight hexafluorobenzene moieties.
Thermooxidation Tests
Test 1--Evaluation of Thermal Stability
[0079] Dynamic TGA analyses of PAO 400/40 and of the modified PAO
of example 1 were carried out in air with a heating rate of
10.degree. C./min. The results are reported in the table below:
TABLE-US-00001 TABLE 1 Modified PAO of PAO 400/40 example 1 Delta
T, Weight loss Temperature, .degree. C. .degree. C. 1% 251 291 40
2% 266 313 47 10% 309 367 58 50% 369 434 65
[0080] The results show that the same weight loss in the modified
PAO of Example 1 as in PAO 400/40 was observed at temperatures
40-65.degree. C. higher; thus, the modified PAO according to the
invention has a higher thermal stability.
Test 2--Evaluation of Thermo-Oxidative Stability
[0081] 20 g PAO 400/40 and 20 g modified PAO of example 1 were
placed in two 100 ml glass flasks and heated to 200.degree. C. for
12 hours under magnetic stirring in the presence of air. The
content of carbonyl groups in each PAO (50% wt solution in
n-hexane) was measured by FT-IR analysis (the peaks of the carbonyl
groups fall in the range of 1719 to 1721 cm.sup.-1).
[0082] The results are reported in table 2 below:
TABLE-US-00002 TABLE 2 Intensity of carbonyl peaks at 1719-1721
cm.sup.-1, Ht Sample 0 h 4 h 8 h 12 h PAO 400/40 0.00 0.18 0.46 0.7
1.55 Modified 0.20 0.25 0.30 0.35 0.80 PAO of Example 1
[0083] The results show that in the modified PAO of the invention
there is a significantly lower increase of carbonyl groups content
than in PAO 400/40; thus, the modified PAO of the invention is
endowed with higher thermooxidation stability.
Test 3--Tribological Test
[0084] Tribological test were carried out in an SRV.RTM. test
machine according to ASTM D6425-05 (2010). Decrease of COF
(coefficient of friction) and wear was observed in the modified
PAOs of Examples 1 and 2, and in blends of modified PAO of Example
1 with PAO 400/40 in comparison with the corresponding unmodified
PAOs.
TABLE-US-00003 TABLE 3 Tem- Load, perature, .DELTA. .DELTA. Sample
N .degree. C. COF COF, % wear wear, % PAO 400/40 300 50 0.158 --
0.74 -- Modified PAO of 300 50 0.110 29.5 0.60 19 Example 1
Modified PAO of 300 50 0.112 29.1 0.62 16 Example 1-bis Blend 25%
w/w of 300 50 0.108 31.6 0.63 15 modified PAO (example 1) 75% w/w
of PAO 400/40 PAO 400/40 50 80 0.181 -- 0.46 -- Modified PAO of 50
80 0.124 33.1 0.25 46 Example 1 Modified PAO of 50 80 0.115 36.5
0.28 39 Example 1-bis Blend 25% w/w of 50 80 0.114 37.0 0.27 41
modified PAO (example 1) 75% w/w of PAO 400/40 PAO 65/40 50 25
0.211 -- 0.54 -- Modified PAO of 50 25 0.122 42 .0.29 47 Example 2
PAO 65/40 50 80 0.145 -- 0.45 -- Modified PAO of 50 80 0.132 9 0.33
27 Example 2
[0085] Test 4--Evaluation of the Thermal Stability of the Product
of Example 7
[0086] Dynamic TGA analyses of PAO 65/40 and of the modified PAO of
example 7 were carried out in air with a heating rate of 10.degree.
C./min. The results are reported in the table below:
TABLE-US-00004 TABLE 4 Modified PAO of PAO 65/40 Example 7 Delta T,
Weight loss Temperature, .degree. C. .degree. C. 1% 241 251 10 2%
252 266 14 10% 286 308 22 50% 333 368 35
[0087] The results show that the same weight loss in the modified
PAO of Example 1 as in PAO 400/40 was observed at temperatures
10-35.degree. C. higher; thus, the modified PAO according to the
invention has a higher thermal stability.
[0088] Test 5--Evaluation of Thermo-Oxidative Stability of the
Product of Example 7
[0089] 20 g PAO 65/40 and 20 g modified PAO of Example 7 were
placed in two 100 ml glass flasks and heated to 200.degree. C. for
12 hours under magnetic stirring in the presence of air. The
content of carbonyl groups in each PAO (50% wt solution in
n-hexane) was measured by FT-IR analysis (the peaks of the carbonyl
groups fall in the range of 1719 to 1721 cm.sup.-1).
[0090] The results are reported the table below:
TABLE-US-00005 TABLE 5 Intensity of carbonyl peaks at 1719-1721
cm-1, .DELTA. peak at Ht 1719-1721 cm.sup.-1, Ht Compound 0 h 24 h
After 24 h PAO 65/40 0.00 2.00 2.00 Modified 0.60 0.75 0.15 PAO of
Example 7
* * * * *