[0001] The present invention relates to turbine and rust and oxidation (R&O) oils (hereinafter
"turbine oils") having improved wet filterability without detriment to hydrolytic
stability.
[0002] Steam and gas turbine oils are top-quality rust- and oxidation-inhibited oils. Steam
turbines employ steam that enters the turbine at high temperature and pressure and
expands across both rotating and fixed blades. Only the highest-quality lubricants
are able to withstand the wet conditions, high temperatures and long periods of service
associated with steam turbine operation. In gas turbines, they must withstand contact
with very hot surfaces, often with intermittent operation and periods of nonuse. Therefore,
to be effective, both types of oil must have, in addition to good corrosion protection
and demulsibility, outstanding resistance to oxidation, which includes a minimum tendency
to form deposits in critical areas of the system.
[0003] To achieve these desired properties, it is necessary to formulate these oils from
specially refined base stocks of the highest quality plus a carefully balanced additive
package. The nature of these fluids makes them very susceptible to contamination,
particularly from other lubricants and additives. A relatively small degree of contamination
can markedly affect the properties and expected service life of these lubricants.
Further, to maintain effective operating conditions and to avoid damaging the equipment
in which they are used, turbine oils should be kept meticulously clean and free of
contaminants. Contamination is minimized by filtration of the turbine oils. To ensure
that the turbine oils are substantially free of contaminants very fine filters are
used.
[0004] Due to the requirements of turbine oils, only a few classes of additives, relative
to other types of lubricating compositions, are combined with the base oils. Generally,
a finished turbine oil will contain only the base oil, antioxidants, rust inhibitors,
demulsifiers, corrosion inhibitors and diluents, if necessary.
[0005] Prior art turbine oils contain acidic rust inhibitors. For example, acidic rust inhibitors,
of the type taught in U.S. Patent No. 4,101,429, have been used in turbine oils. Although,
turbine oils containing acidic rust inhibitors exhibit satisfactory rust performance,
they tend to interact with, for example, water and metal detergents present as contaminants
producing particulates, precipitates and/or sludge. Acidic rust inhibitors thus create
problems with deposit formation and filterability upon exposure to contaminants such
as water and/or metal detergents. The resulting filterability problems and deposit
formation are expensive and highly undesirable.
[0006] US-A-2971912 discloses antioxidants for use in synthetic-ester lubricants suitable
for use in gas turbines. EP-A-776964 discloses ZDDP-containing hydraulic fluids, which
exhibit improved wet-filtrability.
[0007] It is an object of this invention to provide turbine oils that exhibit good rust
performance as well as good wet filterability and good thermal stability upon exposure
to contaminants such as water and/or detergents. This objective is attained, in one
embodiment of the present invention, by the use of specific neutral rust inhibitors,
in place of acidic rust inhibitors, in preparing the finished turbine oils. The term
"neutral rust inhibitors", in the present specification, means rust inhibitors that
are essentially free of a -COOH functional group.
[0008] Accordingly, the present invention provides a composition which is suitable for use
as a turbine or rust and oxidation (R&O) oil and which is substantially free of acidic
rust inhibitor, which composition comprises:
(a) a major portion of a hydro-processed mineral oil which has a viscosity index of
greater than 80, a saturates content of greater than 90 wt% and a sulfur content of
0.5 wt% or less;
(b) at least 0.10 wt% of at least one neutral rust inhibitor, which is a hydrocarbyl
ester of formula R(COOR')n, in which R and R' are each independently hydrocarbyl groups or hydroxyhydrocarbyl
groups containing up to 40 carbon atoms, and n is from 1 to 4; and
(c) a compound (B) of formula:

in which Z is a group R1R2CH-, in which R1 and R2 are each independently hydrocarbyl groups containing up to 34 carbon atoms, the total
number of carbon atoms in the groups R1 and R2 being from 11 to 35.
[0009] Those skilled in the art will appreciate that the mineral oils used in the present
invention are commonly referred to as Group II, Group III oils. The viscosity index
is assessed in accordance with IP 226. The saturates and sulfur content are assessed
by mass spectroanalysis.
[0010] The term "major portion" means that the composition contains at least 50% by weight
base oil.
[0011] The turbine oils of the present invention have good rust performance, good wet filterability
and good performance in thermal stability tests where water and/or metal detergents
are present, e.g. the ASTM D 2619 and ASTM D 4310 tests.
[0012] Unless otherwise stated all hydrocarbyl groups and moieties may be straight- or branched-chain.
[0013] In another embodiment of the present invention, turbine oils are produced which are
substantially free of metal detergents. For purposes of the present invention, the
term "substantially free" means that no acidic rust inhibitors or metal detergents
are purposefully added to the finished oil although there may be some present due
to contamination or as an impurity.
[0014] Preferably, R and R' in the at least one neutral rust inhibitor of formula R(COOR')
n are each independently hydrocarbyl groups or hydroxyhydrocarbyl groups containing
8 to 20 carbon atoms.
[0015] It will be appreciated that the maximum number of groups COOR' which are present
on the hydrocarbyl or hydroxyhydrocarbyl group R will vary depending on the number
of carbon atoms in R. For example, if R is a hydrocarbyl group containing only one
carbon atom, the maximum possible value of n will be 4. When R is a hydroxyhydrocarbyl
group containing one carbon atom the maximum value of n will be 3.
[0016] The hydrocarbyl esters can be prepared by conventional esterification procedures
from a suitable alcohol and an acid, acid halide, acid anhydride or mixtures thereof.
Also, the esters of the invention can be prepared by conventional methods of transesterification.
By "essentially free", it is meant that the starting acids, acid halides, acid anhydrides
or mixtures thereof used in preparing the neutral rust inhibitors are reacted with
an amount of alcohol sufficient to theoretically convert all of the -COOH groups to
esters. Typically, the neutral rust inhibitor will have a TAN of less than 10mgKOH/g.
Preferred esters include, but are not limited to, octyloleyl malate, dioleylmalate,
pentaerythritol monooleate and glycerol monooleate.
[0017] In compound (B) the radical Z may be, for example, 1-methylpentadecyl, 1-propyltridecenyl,
1-pentyltridecenyl, 1-tridecenylpentadecenyl or I-tetradecyleicosenyl. Preferably,
the number of carbon atoms in the groups R
1 and R
2 is from 16 to 28 and more commonly 18 to 24. It is especially preferred that the
total number of carbon atoms in R
1 and R
2 is 20 to 22. The preferred compound (B) is 3-C
18-24 alkenyl-2,5-pyrrolidindione, i.e. a compound in which the average number of carbon
atoms in the alkenyl group is from 18 to 24.
[0018] In one aspect of the invention, the compound (B) has a titratable acid number (TAN)
of 80 to 140 mgKOH/g, preferably 110mgKOH/g. The TAN is determined in accordance with
ASTM D 664.
[0019] The compounds (B) are commercially available or may be made by the application or
adaptation of known techniques (see for example EP-A-0389237).
[0020] Lubricating oils contemplated for use in this invention are hydro-processed mineral
oils. Suitable lubricating oils include basestocks produced by hydrocracking (rather
than solvent extracting) the aromatic and polar components of crude oil. In general,
the lubricating oils will have a kinematic viscosity ranging from 1 x 10
-6 m
2/s to 40 x 10
-6 m
2/s (1 to 40 cSt) at 100°C.
[0021] The mineral oils useful in this invention include all common mineral oil base stocks.
This would include oils that are naphthenic or paraffinic in chemical structure. They
may be hydrotreated or hydro-refined, dewaxed by chilling or catalytic dewaxing processes,
or hydrocracked. The mineral oil may be produced from natural crude sources or be
composed of isomerized wax materials or residues of other refining processes.
[0022] Typically the mineral oils will have kinematic viscosities of from 2 x 10
-6 m
2/s to 12 x 10
-6 m
2/s (2 cSt to 12 cSt) at 100°C. The preferred mineral oils have kinematic viscosities
of from 3 x 10
-6 m
2/s to 10 x 10
-6 m
2/s (3 to 10 cSt), and most preferred are those mineral oils with viscosities of 5
x 10
-6 m
2/s to 9 x 10
-6 m
2/s (5 to 9 cSt) at 100°C.
[0023] The base oils have a viscosity index (VI) of greater than 80, a saturates content
of greater than 90 wt% and sulfur content of 0.5 wt% or less. In a preferred embodiment
the oils have a sulfur content of 0.3 wt% or less, more preferably 0.1 wt% or less.
[0024] The turbine and R&O oils of the present invention may be prepared by simple blending
of the various components with a suitable base oil.
[0025] For the sake of convenience, and in a preferred embodiment of the present invention,
the additive component(s) used in practice of this invention may be provided as a
concentrate for formulation into a turbine or R&O oil ready for use. Concentrates
of the present invention containing both neutral rust inhibitor(s) and compound (B)
tend to impart greater rust protection in the presence of sea water (ASTM D665B) than
concentrates lacking the compound (B), and are typically added to the base oil at
a treat rate of from 0.2 to 2%, for example, 0.3 to 2%, by weight based on the weight
of the finished oil.
[0026] In the present invention, the neutral rust inhibitor(s) are generally present in
the additive concentrate in an amount of from 10 to 60 percent by weight, based on
the total weight of the concentrate, while compound (B) is generally present in the
additive concentrate in an amount of from 1 to 15 percent by weight. The concentrate
may comprise, in addition to the additive components, a solvent or diluent for the
additive components. The solvent or diluent should be miscible with and/or capable
of dissolving in the turbine base oil to which the concentrate is to be added. Suitable
solvents and diluents are well known. The solvent or diluent may be the turbine base
oil itself The concentrate may suitably include any of the conventional additives
used in turbine oils. The proportions of each component of the concentrate are controlled
by the intended degree of dilution.
[0027] Whether added directly to the base oil, or in the form of a concentrate, the neutral
rust inhibitor(s) should be present in the finished oil in an amount of at least about
0.10, and preferably from 0.10 to 0.45 percent by weight. Whether added directly to
the base oil, or in the form of a concentrate, compound (B) should be present in the
finished oil in an amount of 0.008 to 0.25 percent by weight.
[0028] The additive concentrates and finished oils of the present invention may further
contain additional additives such as phosphorus-containing additives and sulfurized
esters. Preferred phosphorus containing additives include amine salts of acid phosphates
and phosphorus and sulfur containing compounds.
[0029] Other additives commonly used in turbine and R&O oils may be included in the turbine
and R&O oils of the present invention. These include antioxidants, demulsifiers and
corrosion inhibitors. These additives, when present, are used in amounts conventionally
used in turbine oil packages.
[0030] The invention will now be illustrated by the following Examples.
EXAMPLES
[0031] In Table 1, the formulations for various turbine oil concentrates are set forth.
Turbine Oil Concentrate 1 represents a formulation within the scope of the present
invention, i.e., it contains a neutral rust inhibitor and compound (B) and is substantially
free of acidic rust inhibitor. Turbine Oil Concentrate 2 represents an additive concentrate
outside of the scope of the present invention in that it contains an acidic rust inhibitor.
All of the samples used similar conventional additives (e.g., antioxidants, demulsifiers
and corrosion inhibitors) in similar amounts.
Table 1:
| Turbine Oil Concentrates |
| |
Turbine Oil 1 (TO1) |
Turbine Oil 2 (TO2) (Comparative) |
| Rust Inhibitor X |
22.50 |
|
| Rust Inhibitor Z |
|
12.00 |
| Compound B |
5.00 |
|
- RI X:
- Pentaerythritol monooleate neutral rust inhibitor.
- RI Z:
- An acidic rust inhibitor comprising the reaction product of oleic acid, triethylene
tetramine and maleic anhydride substituted by a C12 alkenyl group of the kind described
in U.S. Patent No. 4,101,429.
- Comp. B:
- 3-C18-24 alkenyl-2,5-pyrrolidindione.
[0032] Turbine oils are prepared by adding additive concentrates as described above to base
oils of various viscosities at a treat rate of 0.8 percent by weight. The base oil
used was a hydro-processed (HP) mineral oils having a VI of at least 98, a saturates
level of at least 98% and a sulfur content of less than 0.01 wt%. A solvent refined
(SR) base oil was also used. The finished oils were tested for wet filterability using
the Shell Filtration Test and for rust performance using the ASTM D 665B rust test.
[0033] The Shell Filtration Test is intended to evaluate the filterability characteristics
of oil based hydraulic fluids with and without calcium and/or water contamination.
The fluids as blended and the contaminated fluids are each tested in duplicate as
follows. After pre-treatment at 70 °C, 300 ml of test oil are filtered through a 1.2
micron Millipore membrane using a 650 mm Hg vacuum. The fluid temperature is not controlled
but should be in the range of 19 to 26 °C. The times for each successive 100 ml of
fluid to filter, or for the filter membrane to block, are noted. In the following
Tables the results of the Shell Filtration Test are indicated as either PASS, meaning
that all 300 ml of oil passed through the filter, or FAIL, meaning that the filter
became blocked.
[0034] The results of the Shell Filtration Test and the ASTM D 665B rust test are set forth
below in Table 2.
Table 2:
| Shell Filtration and ASTM D 665B Rust Test results |
| Additive Concentrate |
Base Oil - ISO # |
Shell Filtration Test |
D665B rust test |
| TO1 |
HP - 32 |
PASS |
PASS |
| TO2 |
SR - 32 |
FAIL |
PASS |
| |
| TO2 |
SR- 46 |
FAIL |
PASS |
| |
| TO1 |
HP - 68 |
PASS |
PASS |
| TO2 |
SR - 68 |
FAIL |
PASS |
| |
| TO1 |
HP -100 |
PASS |
PASS |
[0035] It is clear from the above Table that compositions of the present invention exhibit
both passing Shell Filtration results and ASTM D 665B results. Further, it is clear
from the above Table 2 that turbine oils (TO2) containing sufficient amounts of acidic
rust inhibitor to pass the ASTM D 665B rust test fail the Shell Filtration Test.
[0036] In handling, i.e., storing and transporting, of turbine oils, the turbine oil often
comes into contact with residual lubricating fluids containing acidic rust inhibitors
and/or metal detergents or turbine oils containing acidic rust inhibitors. The turbine
oils of the present invention enable passing Shell Filtration Test results upon contamination
with these sources of acidic rust inhibitors and/or metal detergents.
[0037] For some applications, oxidation performance in the presence of water is desired
along with acceptable rust test performance. Turbine oils containing components (A)
and (B) of the present invention have been found to exhibit excellent thermal stability
in tests with water present and passing rust test performance. ASTM D 4310 is used
to determine the tendency of inhibited mineral oils, especially turbine oils, to form
sludge during oxidation in the presence of oxygen, water, and copper and iron metals
at an elevated temperature. In this test, an oil sample is reacted with oxygen in
the presence of water and an iron-copper catalyst coil for 1000 hours. The oil is
then analysed to determine the total acid number (TAN), the weight of sludge and loss
of copper and iron from the catalyst. Table 3 shows the hydrolytic stability in the
presence of water of turbine oils containing the combination of additives (A) and
(B) of the present invention.
[0038] The formulated oil included pentaerythritol monooleate at a concentration of 0.18
wt % and 3-C
18-24 alkenyl-2,5-pyrrolidindione at a concentration of 0.04 wt%. The base oil was a hydro-processed
basestock having a viscosity index of 99, a saturates content of 99.5 wt % and a sulfur
content of 0.02 wt %.
Table 3
| Sludge (mg) |
Copper wt. Change (mg) |
Iron wt. change (mg) |
TAN (mg/KOH g) |
| 12.5 |
0.5 |
0.75 |
0.425 |
The results represent the average of 2 runs.
[0039] The additive combinations used in the present invention are especially effective
in hydro-processed mineral oils. Table 4 demonstrates the exceptional properties of
the additive systems used in the present invention in these hydro-processed mineral
oils. The following formulated oils contained identical additive concentrates (TO1).
The solvent refined mineral oils (SR-32 and SR-68) contained 0.82 wt% of TO1, while
the hydro-processed mineral oils (HP-32, HP-68 and HP-100) contained 0.80 wt% of TO1.
The formulated oils were tested in the Rotating Bomb Oxidation Test (RBOT) defined
in ASTM D-2272. The RBOT is a test for estimating the oxidation stability of turbine
oils. The test oil, water and copper catalyst coil, contained in a covered glass container,
are placed in a bomb equipped with a recording pressure gauge. The bomb is charged
with oxygen to a pressure of 620 kPa, placed in a constant-temperature oil bath set
at 150 °C, and rotated axially at 100 rpm at an angle of 30° from the horizontal.
The number of minutes required to reach a specific drop in gauge pressure is the oxidation
stability of the test sample.
[0040] The formulated oils containing solvent refined basestocks were also tested in the
Lifetime Turbine Oil Oxidation Test (Life TOST) as defined in ASTM D-943. The Life
TOST is used to evaluate the oxidation stability of inhibited steam turbine oils.
In the Life TOST, the oil sample is reacted with oxygen in the presence of water and
an iron-copper catalyst at 95 °C. The test continues until the measured total acid
number of the oil is 2.0 mg KOH/g. The number of test hours required for the oil to
reach 2.0 mg KOH/g is the "oxidation lifetime". The RBOT for base oil alone would
be in the region of 15-30 minutes.
Table 4
| Base oil |
RBOT (minutes) |
Life TOST (hours) |
| SR-32 |
602.5 |
6188 |
| (avg. of 2 runs) |
| HP-32 |
1199 |
|
| (avg. of 3 runs) |
|
| SR-68 |
707.5 |
6032 |
| (avg. of 2 runs) |
| HP-68 |
1292 |
|
| (avg. of 3 runs) |
|
| HP-100 |
1253 |
|
| (avg. of 3 runs) |
|
[0041] It is clear from Table 4 that the turbine oils prepared from hydro-processed mineral
oils exhibit superior oxidation stability, compared to solvent refined mineral oils,
as evidenced by the increased (nearly doubled) length of the RBOT for the turbine
oils prepared from hydro-processed mineral oils. As is readily apparent from Table
4, the Life TOST for the turbine oils prepared from solvent refined mineral oils was
over 250 days. Due to the extremely long test time for these oils the RBOT may be
used as a tool to predict Life TOST results. In the paper Mookken, RT. et al.,
Dependence of Oxidation Stability of Steam Turbine Oil on base Oil Composition, Lubrication Engineering, October 1997, pages 19-24, it was shown that the RBOT can
be used as a screening test to get an indication of the TOST life of the blended turbine
oil. The study shows that the RBOT and Life TOST are directly proportional. Thus,
it is clear from Table 4 that the turbine oils prepared from hydro-processed mineral
oils will exhibit superior oxidation stability as determined by Life TOST in view
of their significantly longer RBOT life.
1. A composition which is suitable for use as a turbine or rust and oxidation (R&O) oil
and which is substantially free of acidic rust inhibitor, which composition comprises:
(a) a major portion of a hydro-processed mineral oil which has a viscosity index of
greater than 80, a saturates content of greater than 90 wt% and a sulfur content of
0.5 wt% or less;
(b) at least 0.10 wt% of at least one neutral rust inhibitor, which is a hydrocarbyl
ester of formula R(COOR')n, in which R and R' are each independently hydrocarbyl groups or hydroxyhydrocarbyl
groups containing up to 40 carbon atoms, and n is from 1 to 4; and
(c) a compound (B) of formula:

in which Z is a group R
1R
2CH-, in which R
1 and R
2 are each independently hydrocarbyl groups containing up to 34 carbon atoms, the total
number of carbon atoms in the groups R
1 and R
2 being from 11 to 35.
2. A composition according to claim 1, wherein the at least one neutral rust inhibitor
is present in an amount of from 0.10 to 0.45% by weight.
3. A composition according to claim 1 or 2, wherein R and R' are each independently hydrocarbyl
groups or hydroxyhydrocarbyl groups containing 8 to 20 carbon atoms.
4. A composition according to any one of the preceding claims, further comprising at
least one additive selected from sulfurized esters, phosphorus-containing additives,
phosphorus- and sulfur-containing additives, antioxidants, demulsifiers and corrosion
inhibitors.
5. A composition according to any one of the preceding claims, wherein the total number
of carbon atoms in the groups R1 and R2 is 18 to 24.
6. A composition according to any one of the preceding claims, wherein compound (B) is
a 3-C18-24 alkenyl-2,5-pyrrolidindione.
7. A composition according to any one of the preceding claims, comprising from 0.10 to
0.45% by weight of said at least one neutral rust inhibitor and from 0.008 to 0.25%
by weight of compound (B).
8. Use, in a turbine or rust and oxidation (R&O) base oil which is substantially free
of acidic rust inhibitor and which is a hydro-processed mineral oil which has a viscosity
index of greater than 80, a saturates content of greater than 90 wt% and a sulfur
content of 0.5 wt% or less,
of at least 0.10 wt% of at least one neutral rust inhibitor as defined in any one
of claims 1 to 3 and a compound (B) as defined in any one of claims 1, 5 or 6,
to improve the wet-filterability of the base oil, to improve the hydrolytic stability
of the base oil and/or to reduce the formation in the base oil of sludge, precipitates
and/or particulates by reaction with water and/or metal detergents.
9. A method of operating a steam or gas turbine, wherein the turbine is lubricated with
a composition according to any of claims 1 to 7.
1. Zusammensetzung, die für die Anwendung als Turbinenöl oder Rost- und Oxidationsinhibitionsöl
(R&O-Öl) geeignet und im Wesentlichen frei von sauren Rostinhibitoren ist, wobei die
Zusammensetzung umfasst:
(a) eine Hauptmenge eines hydroprozessierten Mineralöls, das einen Viskositätsindex
von über 80, eine Gehalt an gesättigten Verbindungen von über 90 Gew.-% und einen
Schwefelgehalt von 0,5 Gew.-% oder darunter aufweist;
(b) mindestens 0,10 Gew.-% mindestens eines neutralen Rostinhibitors, bei dem es sich
um einen Hydrocarbylester der Formel R(COOR')n handelt, worin R und R' jeweils unabhängig Hydrocarbylgruppen oder Hydroxyhydrocarbylgruppen
mit bis zu 40 Kohlenstoffatomen darstellen und n von 1 bis 4 ist; und
(c) eine Verbindung (B) der Formel:

worin Z eine Gruppe R
1R
2CH- darstellt, worin R
1 und R
2 jeweils unabhängig Hydrocarbylgruppen sind, enthaltend bis zu 34 Kohlenstoffatome,
wobei die Gesamtzahl der Kohlenstoffatome in den Gruppen R
1 und R
2 von 11 bis 35 beträgt.
2. Zusammensetzung gemäß Anspruch 1, worin der mindestens eine neutrale Rostinhibitor
in einer Menge von 0,10 bis 0,45 Gew.-% vorliegt.
3. Zusammensetzung gemäß Anspruch 1 oder 2, worin R und R' jeweils unabhängig Hydrocarbylgruppen
oder Hydroxyhydrocarbylgruppen darstellen, enthaltend 8 bis 20 Kohlenstoffatome.
4. Zusammensetzung gemäß einem der vorstehenden Ansprüche, zusätzlich umfassend mindestens
ein Additiv, ausgewählt unter geschwefelten Estern, Phosphor enthaltenden Additiven,
Phosphor und Schwefel enthaltenden Additiven, Antioxidantien, Demulgatoren und Korrosionsinhibitoren.
5. Zusammensetzung gemäß einem der vorstehenden Ansprüche, worin die Gesamtzahl der Kohlenstoffatome
in den Gruppen R1 und R2 18 bis 24 beträgt.
6. Zusammensetzung gemäß einem der vorstehenden Ansprüche, worin die Verbindung (B) ein
3-C18-24-alkenyl-2,5-pyrrolidindion ist.
7. Zusammensetzung gemäß einem der vorstehenden Ansprüche, umfassend von 0,10 bis 0,45
Gew.-% des mindestens einen neutralen Rostinhibitors und von 0,008 bis 0,25 Gew.-%
der Verbindung (B).
8. Verwendung in einem Turbinenöl oder Rost- und Oxidationsinhibitionsgrundöl (R&O-Grundöl),
das im Wesentlichen frei von sauren Rostinhibitoren ist und bei dem es sich um ein
hydroprozessiertes Mineralöl handelt, das einen Viskositätsindex von größer 80, einen
Gehalt an gesättigten Verbindungen von größer 90 Gew.-% und einen Schwefelgehalt von
0,5 Gew.-% oder darunter aufweist,
von mindestens 0,10 Gew.-% mindestens eines neutralen Rostinhibitors, wie in einem
der Ansprüche 1 bis 3 definiert, und einer Verbindung (B), wie in einem der Ansprüche
1, 5 oder 6 definiert,
zur Verbesserung der Nassfiltrierbarkeit des Grundöls, zur Verbesserung der hydrolytischen
Stabilität des Grundöls und/oder zur Verringerung von Schlamm, Präzipitaten und/oder
Teilchen im Grundöl durch Reaktion mit Wasser und/oder Metalldetergentien.
9. Verfahren des Betriebs einer Dampf- oder Gasturbine, worin die Turbine mit einer Zusammensetzung
nach einem der Ansprüche 1 bis 7 geschmiert wird.
1. Composition qui est apte à l'utilisation comme huile pour turbines ou huile antirouille
et anti-oxydante (R&O) et qui est pratiquement dépourvue d'agent antirouille acide,
composition qui comprend :
(a) une proportion dominante d'une huile minérale hydrotraitée qui a un indice de
viscosité supérieur à 80, une teneur en composés saturés supérieure à 90% en poids
et une teneur en soufre égale ou inférieure à 0,5% en poids ;
(b) au moins 0,10% en poids d'au moins un agent antirouille neutre, qui est un ester
hydrocarbylique de formule R(COOR')n, dans laquelle R et R' représentent chacun indépendamment des groupes hydrocarbyle
ou groupes hydroxyhydrocarbyle contenant jusqu'à 40 atomes de carbone, et n a une
valeur de 1 à 4 ; et
(c) un composé (B) de formule :

dans laquelle Z représente un groupe R
1R
2CH-, dans lequel R
1 et R
2 représentent chacun indépendamment des groupes hydrocarbyle contenant jusqu'à 34
atomes de carbone, le nombre total d'atomes de carbone dans les groupes R
1 et R
2 allant de 11 à 35.
2. Composition suivant la revendication 1, dans laquelle ledit au moins un agent antirouille
neutre est présent en une quantité de 0,10 à 0,45 % en poids.
3. Composition suivant la revendication 1 ou 2, dans laquelle R et R' représentent chacun
indépendamment des groupes hydrocarbyle ou groupes hydroxyhydrocarbyle contenant 8
à 20 atomes de carbone.
4. Composition suivant l'une quelconque des revendications précédentes, comprenant en
outre au moins un additif choisi entre des esters sulfurés, des additifs contenant
du phosphore, des additifs contenant du phosphore et du soufre, des anti-oxydants,
des désémulsionnants et des inhibiteurs de corrosion.
5. Composition suivant l'une quelconque des revendications précédentes, dans laquelle
le nombre total d'atomes de carbone dans les groupes R1 et R2 va de 18 à 24.
6. Composition suivant l'une quelconque des revendications précédentes, dans laquelle
le composé (B) est une 3(alcényle en C18 à C24)2,5-pyrrolidinedione.
7. Composition suivant l'une quelconque des revendications précédentes, comprenant 0,10
à 0,45% en poids dudit au moins un agent antirouille neutre et 0,008 à 0,25% en poids
de composé (B).
8. Utilisation, dans une huile de base pour turbines ou huile antirouille et anti-oxydante
(R&O) qui est pratiquement dépourvue d'agents antirouille acide et qui est une huile
minérale hydrotraitée ayant un indice de viscosité supérieur à 80, une teneur en composés
saturés supérieure à 90% en poids et une teneur en soufre égale ou inférieure à 0,5%
en poids,
d'au moins 0,10% en poids d'au moins un agent antirouille neutre répondant à la
définition suivant l'une quelconque des revendications 1 à 3 et d'un composé (B) répondant
à la définition suivant l'une quelconque des revendications 1, 5 ou 6,
pour améliorer la filtrabilité à l'état humide de l'huile de base, pour améliorer
la stabilité à l'hydrolyse de l'huile de base et/ou pour réduire 1a formation dans
l'huile de base de boues, de précipités et/ou de particules par réaction avec l'eau
et/ou des détergents métalliques.
9. Procédé pour faire fonctionner une turbine à vapeur ou à gaz, dans lequel la turbine
est lubrifiée avec une composition suivant l'une quelconque des revendications 1 à
7.