CN120752323A

CN120752323A - Use of a lubricant composition comprising at least one base oil and at least one fatty alcohol

Info

Publication number: CN120752323A
Application number: CN202480014228.8A
Authority: CN
Inventors: P·诺里德格
Original assignee: Total Energy Vantech
Current assignee: Total Energy Vantech
Priority date: 2023-01-27
Filing date: 2024-01-25
Publication date: 2025-10-03
Also published as: WO2024156810A1; FR3145361A1

Abstract

本发明涉及包含至少一种基础油和至少一种包含8‑20个碳原子的饱和或不饱和、线性或支化的脂肪醇的润滑剂组合物用于润滑螺杆压缩机中的运动部件的用途。The present invention relates to the use of a lubricant composition comprising at least one base oil and at least one saturated or unsaturated, linear or branched fatty alcohol containing 8-20 carbon atoms for lubricating moving parts in screw compressors.

Description

Use of a lubricant composition comprising at least one base oil and at least one fatty alcohol

Technical Field

The present invention relates to the field of lubricant compositions. These compositions are useful in a variety of applications, particularly for lubricating a variety of mechanical systems, particularly as screw compressor oils.

The invention relates more particularly to the use of at least one specific fatty alcohol as an additive for improving properties of lubricants such as dispersing properties, in other words for maintaining cleaning properties.

Background

Lubricant compositions, also known as "lubricants," are commonly used in mechanical systems to reduce friction between components and thus protect the components from wear. In addition to the abrasion phenomenon, friction also impedes the relative movement between the contacting components and leads to energy losses detrimental to the optimal operation of the mechanical system. To this end, lubricant compositions conventionally consist of a base oil to which are usually combined various additives that are specific to stimulating the lubricating properties of the base oil and also to provide additional performance characteristics.

Lubricants are used in numerous applications, in particular for screw compressors, which are used in particular in fields such as automotive, brewing, food packaging, aerospace or construction.

Lubricants may encounter high temperature conditions during use. They oxidize and degrade in the presence of oxygen. This degradation can lead to the formation of deposits, varnish and sludge, an increase in lubricant viscosity, an increase in lubricant acidity, or blackening of the lubricant.

The oxidative stability of lubricating oils is further reduced by the dissolution of metals in these oils, as the dissolved metals are capable of catalyzing the oxidative degradation of the lubricant.

This degradation results in a loss of initial performance characteristics of the lubricant, which may affect proper operation of the mechanical system. The lubricant may also be contaminated during use by contact with impurities.

These various degradation and contamination phenomena thus lead to a reduced cleanliness of the lubricant and of the mechanical parts in contact with the lubricant. It has therefore proved necessary to replace the lubricant after a certain period of use.

Improving the dispersion properties of lubricants when used in mechanical systems (and in particular reducing the formation of deposits and varnish) is therefore an important lever for extending the life cycle, oil change intervals and maintenance intervals of lubricants.

Thus, limiting or even preventing degradation of the lubricant composition also enables reduction of carbon impact due to smaller amounts of use of the lubricant composition.

To limit the degradation of the lubricant during lubrication (and in particular to reduce the formation of deposits and varnish), the lubricant generally uses high quality base oils such as Polyalphaolefins (PAOs) or high solubility oils such as esters, alkylated naphthalenes, naphthenic oils or alkylbenzenes.

However, these lubricants (particularly PAOs and esters) have high costs, which hamper their use, particularly as oils with a service life of 4000 hours. Moreover, high-solubility lubricants are not always effective in maintaining dispersion properties.

Finding additive addition systems that improve the performance of lubricants in terms of dispersion properties (particularly reducing the formation and/or presence of deposits and varnish films) remains a continuing concern for optimizing lubricant life, extending oil change and maintenance intervals.

Lubricant compositions comprising fatty alcohols to improve the cleanliness of four-cycle vehicle engines have been described in FR 3 066 200A1. However, these compositions are not suitable for screw compressors, especially considering environmental differences (e.g. fuel mixed or not with oil, or temperature differences) specific to each application, or differences in the desired function.

In fact, for an engine, the composition must lubricate and cool the engine components, and kinetic energy can be recovered. In the case of a screw air compressor, the compressed air is recovered and must remain clean and uncontaminated. Thus, the lubricant composition used must possess unique properties, otherwise there is a risk of clogging the entire system.

Thus, for example, lubricant compositions for engines contain very high levels of detergent which are not suitable for use in lubricants for screw compressors, as this can clog the entire device and contaminate it.

Disclosure of Invention

Summary of the invention

The present invention is particularly directed to a novel additive addition (additivation) system for lubricating moving parts in a screw compressor.

More particularly, the present invention aims to provide a novel additive addition system for improving cleanliness during lubrication in screw compressors, and in particular for improving maintenance of dispersion properties of compositions for lubricating moving parts in screw compressors.

Thus, according to a first aspect thereof, the present invention relates to the use of a lubricant composition comprising at least one base oil and at least one saturated or unsaturated, linear or branched fatty alcohol comprising 8-20 carbon atoms for lubricating moving parts in a screw compressor.

The invention also relates to the use of at least one saturated or unsaturated, linear or branched fatty alcohol containing 8 to 20 carbon atoms in a lubricant composition containing at least one base oil for improving the properties of said composition used in screw compressors, and in particular for improving the dispersion-retaining properties ("keep clean" properties) of said composition used in screw compressors.

In the remainder of the present text, fatty alcohols as defined above will be referred to more simply by the term "fatty alcohols" according to the invention.

Surprisingly, the inventors have found that the addition of at least one fatty alcohol according to the invention to a lubricant composition enables a significant improvement in the performance of the composition in terms of the dispersing properties.

In particular, as shown in the examples below, the present inventors have demonstrated that the presence of at least one fatty alcohol according to the invention in a lubricant composition enables to reduce or even prevent the formation of deposits and paint films (vernis).

The service life of the lubricant compositions, in particular in screw compressors, can thus be increased by adding at least one fatty alcohol according to the invention, in particular for a run length of at least 2000 hours, in particular at least 4000 hours, in particular at least 8000 hours, or at least 12000 hours, while maintaining the desired lubricating properties of these compressors.

The interval between two successive oil changes of the screw compressor can be increased.

Furthermore, it has been unexpectedly and advantageously found that the present invention enables the elimination of the ester compounds conventionally used in lubricant compositions comprising high quality base oils such as Polyalphaolefins (PAOs) due to the use of at least one saturated or unsaturated, linear or branched fatty alcohol comprising from 8 to 20 carbon atoms.

According to another aspect, the invention also relates to a method for reducing deposit or varnish formation when lubricating a screw compressor with a lubricant composition comprising at least one base oil, the method comprising adding to the lubricant composition at least one saturated or unsaturated, linear or branched fatty alcohol comprising 8-20 carbon atoms.

The invention also relates to a method for lubricating a screw compressor comprising the step of contacting at least one component of the screw compressor with a lubricant composition comprising at least one base oil and at least one saturated or unsaturated, linear or branched fatty alcohol comprising 8 to 20 carbon atoms.

Other characteristics, variants and advantages of the use of at least one fatty alcohol according to the invention will become more apparent upon reading the following description and examples, given by way of illustration and not limiting of the invention.

The expressions "between and", "from/to", "and" from/to "," change "are to be understood as including boundary values unless otherwise indicated.

Detailed description of the invention

Fatty alcohols

As mentioned above, the fatty alcohols used are saturated or unsaturated, linear or branched fatty alcohols containing from 8 to 20 carbon atoms.

The composition may thus comprise a single fatty alcohol according to the invention or a plurality of different fatty alcohols. If a plurality of different fatty alcohols are present, they may be added separately during the preparation of the lubricant composition, and mixtures thereof may then be formed in situ. They can also be used in the form of mixtures which are already commercially available.

Preferably, the one or more fatty alcohols have a flash point of at least 80 ℃, or even at least 100 ℃.

In particular, the one or more fatty alcohols have a melting point of less than or equal to 15 ℃.

Preferably, the one or more fatty alcohols are liquids.

The one or more fatty alcohols may be selected from saturated or unsaturated, linear or branched fatty alcohols containing from 8 to 20 carbon atoms, preferably from 12 to 20 carbon atoms.

The one or more fatty alcohols are in particular selected from saturated linear or branched fatty alcohols comprising from 8 to 20 carbon atoms, preferably from 12 to 20 carbon atoms.

In particular, the one or more fatty alcohols are selected from saturated linear fatty alcohols comprising from 8 to 20 carbon atoms, preferably from 12 to 18 carbon atoms, or even from 12 to 14 carbon atoms, or saturated branched fatty alcohols comprising from 14 to 20 carbon atoms, preferably from 16 to 20 carbon atoms, which are in particular branched only in the β -position with respect to the alcohol function.

In particular, the one or more fatty alcohols are selected from decyl alcohol (also known as octyl-1-alcohol, CAS number 111-87-5), lauryl alcohol (also known as dodecyl-1-alcohol, CAS number 112-53-8), palmityl alcohol (also known as hexadecan-1-alcohol), myristyl alcohol (also known as tetradecan-1-alcohol, CAS number 112-72-1), stearyl alcohol (also known as stearyl-1-alcohol, CAS number 112-92-5), 2-hexyldecyl alcohol (also known as 2-hexyl-1-decyl alcohol, CAS number 2425-77-6), 2-octyldodecyl alcohol (also known as 2-octyl-1-dodecyl alcohol, CAS number 5333-42-6), and mixtures thereof, preferably selected from lauryl alcohol, 2-hexyldecyl alcohol, 2-octyldodecyl alcohol, and mixtures thereof.

The fatty alcohol may be in the form of a mixture of a plurality of different fatty alcohols, for example a mixture of lauryl alcohol and myristyl alcohol.

The lubricant composition may have a content of the one or more fatty alcohols of less than or equal to 10% by weight, particularly 0.01% to 10% by weight, more particularly 0.02% to 8% by weight, preferably 0.05% to 5% by weight, more preferably 0.1% to 1% by weight, relative to the total weight of the lubricant composition.

In particular, the lubricant composition may have a content of the one or more fatty alcohols of 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt% or 0.9 wt%, relative to the total weight of the lubricant composition.

Lubricant composition

Base oil

The lubricant composition used according to the invention comprises at least one base oil.

The base oil may be selected from base oils conventionally used in the field of lubricant compositions, such as mineral, synthetic or natural animal or vegetable oils, at least partially rerefined oils or mixtures thereof.

This may be a mixture of base oils, for example a mixture of two, three or four base oils.

In the context of the present invention, the expression "at least partially rerefined oil" (also referred to herein in the remainder of the text more simply as "rerefined oil", "reclaimed oil" or "recycled oil") refers to an oil obtained at least in part from a used lubricant composition that has been subjected to one or more known treatment steps such as a rerefining treatment.

According to the present invention, a "used lubricant composition" (or more simply "used lubricant" or "used lubricating oil") refers to any lubricant composition that has been used to lubricate moving parts (particularly metal parts) of a mechanical system, such as, but not limited to, bearings, gear mechanisms, or engines.

The used lubricating oil may be from a variety of sources. In particular, as detailed in the remainder of this document, it may be a lubricant that has been used to lubricate motorized systems, particularly "mobile" systems, or that has been used to lubricate industrial systems, particularly "stationary" systems.

In view of its origin, used lubricating oils, in particular engine lubricating oils, contain a certain amount of degradation products derived from the oil itself or additives contained therein, as well as, for example, metal particles, metal oxides and other elements from the engine. The used oil may contain, among other things, high levels of undesirable elements such as calcium (Ca), iron (Fe), magnesium (Mg), sodium (Na), nickel (Ni), phosphorus (P), silicon (Si), chlorine (Cl), zinc (Zn), and the like.

Methods have been developed for reconditioning or reconditioning used lubricating oils to regenerate the oils and allow their subsequent reuse.

The re-refined lubricating oil is thus an oil obtained from one or more treatment steps of the used lubricant, which treatment steps aim to at least partially remove a certain number of contaminating components present therein, such as dust, water, fuel fractions, metallic elements and other residues resulting from the degradation of additives present in the lubricant.

The base oils of the lubricant compositions contemplated according to the invention may be, in particular, oils of mineral or synthetic origin belonging to groups I to V (as shown in table 1 below) according to the classes defined in the API classification (or their equivalents according to the ATIEL classification), or mixtures thereof.

TABLE 1

Mineral base oils include all types of base oils obtained by atmospheric and vacuum distillation of crude oil followed by refining operations such as solvent extraction, deasphalting, solvent deparaffinization, hydrotreating, hydrocracking, hydroisomerization, and hydrofinishing.

The synthetic base oil may be an ester of a carboxylic acid with an alcohol, a polyalphaolefin or a polyalkylene glycol (PAG) obtained by polymerization or copolymerization of an alkylene oxide containing from 2 to 8 carbon atoms, in particular from 2 to 4 carbon atoms. The polyalphaolefins used as base oils are obtained, for example, from monomers containing 4 to 32 carbon atoms (for example from decene, octene or dodecene) and have a viscosity at 100 ℃ of 1.5 to 150mm ².s^-1 according to standard ASTM D445. Their average molecular weight is generally 250 to 3000 according to ASTM D5296.

In particular, the lubricant composition may comprise at least one base oil selected from the group consisting of polyalphaolefins, esters of carboxylic acids with alcohols, and mixtures thereof.

Mixtures of mineral and synthetic oils, which may be of biological origin, may also be used.

There is generally no limit to the use of different base oils in the lubricant composition, except that they must have properties suitable for the intended use (particularly for screw compressors), in particular viscosity, viscosity index or sulfur content properties.

In particular, the base oil is selected from the group I, group II, group III, group IV and group V oils of the API classification, more particularly from the group II and group III oils of the API classification and mixtures thereof, more preferably from the group II oils.

Preferably, the lubricant composition comprises 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight, of one or more base oils, preferably selected from group II base oils, group III base oils, group IV base oils, group V base oils and mixtures thereof, preferably selected from group II base oils, relative to the total weight of the lubricant composition.

For example, the lubricant composition comprises 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight of one or more base oils selected from group II base oils, mixtures of group II base oils and group III base oils, and group IV base oils, preferably selected from group II base oils.

Advantageously, the presence of at least one fatty alcohol according to the invention makes it possible to reduce or even eliminate the use of high quality oils, such as PAO oils, while maintaining the excellent performance quality of the compositions comprising it, in particular in terms of dispersion properties.

Preferably, the lubricant composition comprises 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight, relative to the total weight of the lubricant composition, of one or more base oils selected from group II base oils and/or group III base oils, preferably group II base oils.

The inventors have shown that the addition of at least one fatty alcohol according to the invention to a group II base oil advantageously enables the composition comprising it to achieve performance quality, in particular in terms of maintaining dispersion properties, which is as good as a mixture of group II and group III base oils.

It has also been shown that the presence of fatty alcohols in lubricant compositions comprising group IV or group V base oils (i.e. high quality oils) also enables improved maintenance of the dispersancy performance of the lubricant compositions.

According to a particular embodiment, the lubricant composition may comprise a group IV or V base oil, in particular a group IV base oil, in particular in an amount of 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight, relative to the total weight of the lubricant composition.

The inventors have shown that the addition of at least one fatty alcohol according to the invention to a group IV base oil advantageously enables the composition comprising it to achieve performance quality, in particular in terms of maintaining dispersion properties, which is at least as good as a mixture of group IV and group V base oils.

In particular, the base oils suitable for use in the present invention may have a kinematic viscosity of 11mm ²/s to 1600mm ²/s measured at 40 ℃ according to standard ASTM D445 (KV 40).

In particular the base oil as described above may be present in the lubricant composition according to the invention in a content of at least 80% by weight, in particular at least 90% by weight, more in particular 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight, relative to the total weight of the composition.

Additive agent

The lubricant composition according to the invention may further comprise any type of additive suitable for the intended use of the lubricant.

All of the additional additives may be introduced in the form of an additive mixture or "package" or may be introduced separately during the formulation of the composition.

The fatty alcohols used according to the invention can be added in combination with one or more additives, in particular as a mixture with an additive package, or separately.

In a particular embodiment, the additional additive may constitute from 0.1% to 30% by weight, in particular from 0.5% to 20% by weight, especially from 1% to 15% by weight, more preferably from 2% to 10% by weight, preferably from 2% to 5% by weight, even more preferably from 2% to 3% by weight, relative to the total weight of the composition.

It is understood that the content of the additional additive does not comprise the content of the fatty alcohol according to the invention.

In particular, the lubricant composition used according to the present invention comprises one or more additional additives selected from the group consisting of additives selected from anionic compounds comprising lipophilic long hydrocarbon chains and hydrophilic heads, friction modifiers, antiwear additives, extreme pressure additives, antioxidants, viscosity Index (VI) improvers, pour Point Depressant (PPD) additives, dispersants, defoamers, demulsifiers, thickeners, corrosion inhibitors, metal deactivators, naphthenic solvents, and mixtures thereof.

It will be appreciated that the nature and amount of the additional additives used are selected so as not to adversely affect the properties of the lubricant composition, in particular the quality of properties imparted by the fatty alcohols used according to the invention.

In particular, the lubricant composition used according to the present invention comprises one or more additional additives selected from the group consisting of anionic compounds comprising lipophilic long hydrocarbon chains and hydrophilic heads, antiwear additives, extreme pressure additives, antioxidants, pour Point Depressant (PPD) additives, defoamers, demulsifiers, corrosion inhibitors, metal deactivators, naphthenic solvents, and mixtures thereof.

Preferably, the lubricant composition used according to the present invention comprises one or more additional additives selected from antiwear additives, extreme pressure additives, antioxidants, pour Point Depressant (PPD) additives, defoamers, demulsifiers, corrosion inhibitors and metal deactivators.

Preferably, the lubricant composition used according to the invention does not comprise a friction modifier additive.

According to the invention, the fatty alcohols used are not friction modifier additives.

Preferably, the lubricant composition used according to the invention does not comprise a thickener.

According to a particular embodiment, the lubricant composition used according to the invention comprises less than 1%, in particular less than 0.1%, more preferably less than 0.01% by weight, relative to the total weight of the composition, of detergent additives different from the fatty alcohol used, or even is free of detergent additives different from the fatty alcohol used.

Preferably, the composition according to the invention does not comprise a detergent additive different from the fatty alcohol used.

Preferably, the lubricant composition according to the invention comprises at least one antiwear additive, extreme pressure additive or a mixture thereof.

Antiwear and extreme pressure additives are specifically used to protect surfaces under friction by forming protective films that adsorb onto these surfaces. There are a wide variety of antiwear additives. The antiwear additive very particularly suitable for the present invention is selected from polysulfide additives, sulfur-containing olefin additives, phosphorus-sulfur additives, amine phosphates and mixtures thereof, and preferably amine phosphates.

According to a particular embodiment, the lubricant composition according to the invention may comprise from 0.01 to 6% by weight, in particular from 0.05 to 4% by weight, preferably from 0.1 to 2% by weight, more preferably from 0.1 to 1% by weight, of antiwear and extreme pressure additives, relative to the total weight of the composition.

According to a particular embodiment, the lubricant composition according to the invention may comprise at least one antioxidant additive.

The antioxidant additive enables to delay degradation of the lubricant composition in use. The antioxidant additive acts in particular as a free radical inhibitor or hydroperoxide breaker.

Among the commonly used antioxidant additives, mention may be made of phenolic antioxidants, amine antioxidant additives, phosphorus-sulfur antioxidant additives. Some of these antioxidant additives (e.g., phosphorus sulfur antioxidant additives) can produce ash. The phenolic antioxidant additive may be ash-free or may be in the form of a neutral or basic metal salt. The antioxidant additive may be chosen in particular from sterically hindered phenols, sterically hindered phenol esters and sterically hindered phenols comprising thioether bridges, diphenylamines and diphenylamines substituted by at least one C ₁-C₁₂ alkyl group, N' -dialkylaryl diamines, and mixtures thereof.

Preferably, the sterically hindered phenol is selected from compounds comprising a phenol group wherein at least one ortho carbon of the carbon bearing the alcohol function is substituted with at least one C ₁-C₁₀ alkyl group, preferably C ₁-C₆ alkyl group, preferably C ₄ alkyl group, preferably a tert-butyl group. Amine compounds are another class of antioxidant additives that may be used, optionally in combination with phenolic antioxidant additives. Examples of amine compounds are aromatic amines, for example of the formula NR ⁵R⁶R⁷, wherein R ⁵ represents an optionally substituted aliphatic or aromatic group, R ⁶ represents an optionally substituted aromatic group, R ⁷ represents a hydrogen atom, an alkyl group, an aryl group or a group of the formula R ⁸S(O)_zR⁹, wherein R ⁸ represents an alkylene group or an alkenylene group, R ⁹ represents an alkyl group, an alkenyl group or an aryl group and z represents 0,1 or 2. Sulfurized alkylphenols or their alkali and alkaline earth metal salts may also be used as antioxidant additives.

According to a particular embodiment, the lubricant composition according to the invention comprises 0.1% to 3% by weight, preferably 0.5% to 2% by weight, relative to the total weight of the composition, of at least one antioxidant additive.

According to a particular embodiment, the lubricant composition used according to the invention comprises less than 1%, in particular less than 0.1%, more preferably less than 0.01% by weight of sulfur-containing additives, or even no sulfur-containing additives, relative to the total weight of the composition. The lubricant composition used according to the invention may further comprise at least one additive selected from anionic compounds comprising lipophilic long hydrocarbon chains and hydrophilic heads.

According to a particular embodiment, the lubricant composition used according to the invention may further comprise at least one pour point depressant additive (also known as "PPD" agent).

Pour point depressants generally improve the low temperature performance of the lubricant compositions of the present invention by slowing the formation of wax crystals. Examples of pour point depressants include polyalkylmethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, and alkylated polystyrenes.

The lubricant composition according to the invention may comprise from 0.05% to 2% by weight, preferably from 0.1% to 1% by weight of pour point depressant, relative to the total weight of the composition.

The lubricant composition used according to the invention may further comprise at least one dispersant.

The dispersant may be selected from Mannich bases, succinimides and derivatives thereof, such as polyisobutylene succinic anhydride derivatives.

Preferably, the lubricant composition used according to the invention does not contain a dispersant.

The lubricant composition used according to the invention may further comprise at least one Viscosity Index (VI) improver additive.

Preferably, the lubricant composition used according to the invention is free of Viscosity Index (VI) improver additives.

The lubricant composition used according to the invention may also comprise at least one antifoaming additive, for example chosen from polar polymers such as polymethylsiloxanes or polyacrylates.

In particular, the lubricant composition according to the invention may comprise from 0.001% to 1% by weight of an antifoaming additive, relative to the total weight of the composition.

It may also contain at least one corrosion inhibitor or metal deactivator, for example a compound such as polyisobutylene succinic anhydride, thiadiazole sulfonate, mercaptobenzothiazole, alkyl phosphite or alkyl amino acetic acid.

They are typically present in the lubricant compositions of the present invention in an amount of 0.01% to 1% by weight relative to the total weight of the composition.

The lubricant composition used according to the present invention may further comprise an aromatic or non-aromatic solvent of an alcohol or non-alcohol type, and in particular a naphthenic solvent. The naphthenic solvent enables the use of a variety of additives in the form of a mixture or package of additives in the naphthenic solvent, which can then be incorporated into the base oil during formulation of the composition.

In particular, the lubricant composition according to the invention may comprise from 0.01% to 5% by weight, preferably from 0.1% to 3% by weight, or from 0.5% to 2% by weight, relative to the total weight of the composition, of a solvent, in particular a naphthenic solvent.

According to a particular embodiment, the lubricant composition used according to the invention comprises less than 1%, in particular less than 0.1%, more in particular less than 0.01% by weight of solvent, in particular naphthenic solvent, or even is free of solvent (in particular naphthenic solvent), relative to the total weight of the composition.

In connection with the formulation of the lubricant composition used according to the invention, the fatty alcohols considered according to the invention may be added separately to the base oil or base oil mixture, optionally followed by the addition of further additional additives.

The additional additives may be added alone or in the form of a mixture of one or more additional additives.

Alternatively, the fatty alcohol may be added to a pre-existing lubricant formulation comprising, inter alia, one or more base oils and additional additives.

The additional additives may be added alone or in the form of one or more additional additive mixtures to form a pre-existing lubricant formulation.

The pre-existing formulation may also be a lubricant formulation that has been commercially available.

The fatty alcohol may also be formulated into an additive package in combination with one or more additional additives. The mixture of additive packages so formed may then be introduced into a base oil or base oil mixture.

According to a particular embodiment, the lubricant composition used according to the invention may comprise, or even consist of:

-a base oil or base oil mixture, in particular as defined above;

-one or more fatty alcohols according to the invention, in particular as defined above;

Optionally, one or more additives different from the fatty alcohol, in particular selected from anionic compounds comprising a lipophilic long hydrocarbon chain and a hydrophilic head, antiwear additives, extreme pressure additives, antioxidants, pour Point Depressant (PPD) additives, defoamers, demulsifiers, corrosion inhibitors, metal deactivators, solvents, in particular naphthenic solvents, and mixtures thereof.

Preferably, the lubricant composition formulated according to the present invention comprises, or even consists of:

-80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight of one or more base oils, in particular selected from group II, group III and group IV base oils and mixtures thereof, in particular group II and group III base oils and mixtures thereof, in particular group II base oils;

-0.01% to 10% by weight, preferably 0.02% to 8% by weight, more particularly 0.05% to 5% by weight, more preferably 0.1% to 1% by weight of one or more fatty alcohols, in particular as defined above, in particular selected from decanol, lauryl alcohol, 2-hexyldecanol, 2-octyldodecanol and mixtures thereof;

-0.1-30% by weight, preferably 1-15% by weight, more preferably 1-5% by weight of one or more additives selected from anionic compounds comprising lipophilic long hydrocarbon chains and hydrophilic heads, antiwear additives, extreme pressure additives, antioxidants, pour Point Depressant (PPD) additives, defoamers, demulsifiers, corrosion inhibitors, metal deactivators, solvents, in particular naphthenic solvents, and mixtures thereof;

The content is expressed relative to the total weight of the lubricant composition.

According to a particular embodiment, the lubricant composition according to the invention has a kinematic viscosity measured at 40 ℃ according to standard ASTM D445 of from 20mm ²/s to 800mm ²/s, preferably from 20mm ²/s to 200mm ²/s.

Application of

The lubricant composition used according to the invention can be used for lubricating moving parts in any type of mechanical system, in particular in gas turbines or steam turbines in the fields of aviation, maritime, rail transportation and power generation, in compressors (in particular screw compressors), in particular in fields such as automobiles, brewing, food packaging, aerospace or construction, in wind power plants, in particular for generating electrical energy, in hydraulic systems and the like.

According to the invention, the composition according to the invention is used for lubricating moving parts in screw compressors, in particular for producing compressed air.

Advantageously, thanks to the invention, the maintenance of the dispersibility of the lubricant composition is improved.

Thus, the lubricant composition may be more particularly useful for maintaining cleanliness of a screw compressor.

Maintaining the dispersancy properties of the lubricant composition and thus the cleanliness of the mechanical system is commonly referred to as a "keep clean" technique.

It is thus intended to represent the fact that the lubricant composition used produces little or no deposits, varnish or any other residue on the surfaces of moving parts of the machine system or in the lubricant composition, in particular during lubrication of the machine system with the lubricant composition.

The dispersibility of the lubricant composition can be evaluated by a test according to the modified ASTM D7873 standard, for example by oxygen bubbling in the lubricant composition at 140 ℃ in the presence of a copper and steel based catalyst, by visual observation, or by a test at 165 ℃ according to JIS K2514, as shown in the examples.

For example, lubricant compositions contemplated according to the present invention may be added to a mechanical system after the spent lubricant formulation is drained to maintain cleanliness of the mechanical system.

In particular, the lubricant compositions contemplated according to the present invention may be used to reduce the formation of deposits and/or varnish in the screw compressor. The screw compressor can thus be kept clean for a longer period of time and its deterioration can be slowed down. In particular, the lubricant compositions contemplated according to the present invention may be used to reduce the frequency of cleaning and replacement of components of a screw compressor. In particular, the lubricant composition contemplated according to the present invention may be used to extend the interval between two successive maintenance operations of a screw compressor.

The fatty alcohols according to the invention may also be used in lubricant compositions comprising at least one base oil to improve the performance of the composition used in screw compressors.

In particular, the fatty alcohols according to the invention can be used to improve the maintenance of the dispersibility of the compositions used in screw compressors.

More particularly, the fatty alcohols according to the invention can be used to slow down or even prevent degradation of the lubricant composition during lubrication of moving parts in screw compressors, in particular to reduce the formation of deposits and/or varnish in the lubricant composition, in particular when lubricating moving parts in screw compressors. The fatty alcohols according to the invention are particularly useful for maintaining the lubricating properties of the lubricant composition during its use. The fatty alcohols according to the invention thus enable an increase in the service life of the lubricant composition while maintaining high lubricating properties.

In particular, the fatty alcohol may be used to increase the service life of the lubricant composition as described above in the screw compressor. In particular, the use of this fatty alcohol makes it possible to lengthen the interval of the screw compressor between two successive oil changes.

Preferably, the interval between the two successive oil changes may be at least 2000 hours, preferably at least 4000 hours, more preferably at least 8000 hours, or even at least 12000 hours of operation of the screw compressor.

The lubricant compositions contemplated according to the present invention may be used to lubricate moving parts in screw compressors, and in particular to lubricate the rotating screws of screw compressors. In particular, the mechanical system is a screw compressor for producing compressed air. The mechanical system may be a oil-injected screw compressor. The screw compressor may be used in a variety of applications, such as in the automotive, brewing, food packaging, aerospace or construction fields.

All features and specific embodiments relating to the fatty alcohols and lubricant compositions comprising the same are also applicable for use and methods according to the present invention.

Detailed Description

The invention will now be described by the following examples, which are given by way of illustration and are not meant to be limiting in any way.

Examples

Measuring performance in terms of cleanliness

The performance of the lubricant composition in terms of cleanliness was evaluated by a test ("TOST", an acronym for "Thermal Oxidation Stability Test (thermal oxidative stability test)" according to the modified ASTM 7873 standard, modified as follows:

the lubricant composition was heated to 140 ℃ in the presence of copper and steel based catalysts in a glass vessel placed in an oil bath. Oxygen was bubbled through the lubricant composition maintained at 140 ℃ for 168 hours. At the end of the test, the visual appearance of the container was observed. Note whether deposits and/or paint films form on the glass surface, and their appearance. The appearance of the catalyst was also observed. Samples of the composition obtained at the end of the test were filtered through a filter to filter out particles greater than 1 μm. Note the color of the filtered particles.

The visual appearance of the resulting filtered particles and glass containers enabled classification of the performance of the evaluated lubricant composition in terms of cleanliness maintenance:

the 0 glass vessel was covered with opaque black deposits and/or paint films, and the filtered particles were black/very dark brown;

The + glass vessel is covered with a somewhat transparent black/dark brown deposit and/or paint film and the filtered particles are black/dark brown;

the++ glass container is covered with transparent black deposits and/or paint films and the filtered particles are black/dark brown;

++ glass container cover covered with a slight transparent deposits and/or paint films, and the filtered particles were black/dark brown;

++++ glass Container with a cover no deposit can be seen on the surface of the glass, and the filtered particles were yellow/pale beige.

Preparation and evaluation of the composition according to the invention and of the comparative composition

The lubricant compositions (I1 to I16) and the comparative lubricant compositions (C1 to C5) according to the invention were formulated by adding concentrates of the additives in the solvent or by adding each additive individually (i.e. in the absence of solvent) in the weight percentages indicated in the table below. Percentages are expressed by weight relative to the total weight of the composition.

The additive is a mixture of additives comprising one or more antioxidant additives, pour point depressants, extreme pressure additives, antiwear additives, corrosion inhibitors, one or more metal deactivators, one or more demulsifiers, and/or one or more antifoaming additives.

The composition of the additive mixture is the same for compositions C1 and I1 to I7, compositions C2 and I11, compositions I8 to I10, compositions C3, I12 and I13, and compositions C5, I15 and I16.

The cleanliness performance of the lubricant compositions was evaluated according to the TOST test described above. The following table summarizes the classifications for each composition.

TABLE 2

Composition and method for producing the same	C2	I8	I9	I10	I11
						Group II base oils [% ]	96.5	96	96	94.5	91.5
Solvent [% ]	0.7	0.97	0.97	0.97	0.7
						Additive [% ]	2.8	2.53	2.53	2.53	2.8
2-Hexyldecanol (C ₁₆) [% ]	-	-	0.5	-	-
						2-Octyl dodecanol (C ₂₀) [% ]	-	0.5	-	2	5
Cleanliness performance	0	++	++	++++	+

TABLE 3 Table 3

Composition and method for producing the same	C3	I12	I13
				Group II base oils [% ]	98.18	93.18	93.18
Additive [% ]	1.82	1.82	1.82
				2-Hexyldecanol (C ₁₆) [% ]	-	-	5
2-Octyl dodecanol (C ₂₀) [% ]	-	5	-
				Cleanliness performance	0	+	+

TABLE 4 Table 4

Composition and method for producing the same	C4	I14
			Group II base oils [% ]	100	98
2-Octyl dodecanol (C ₂₀)	-	2
			Cleanliness performance	+	++++

TABLE 5

TABLE 6

The inventive compositions comprising the fatty alcohols according to the invention were observed to exhibit higher cleanliness at the end of the test than compositions without fatty alcohols.

Comparison of compositions I2 and I10 also shows that compositions comprising group II base oils and the fatty alcohols of the present invention, but not group III base oils, can achieve similar cleanliness performance as compared to similar compositions further comprising group III base oils.

Comparison of compositions C5 and I16 also shows that compositions comprising group IV base oils and the fatty alcohols of the present invention, but not group V base oils, can achieve greater cleaning performance than similar compositions further comprising group V base oils.

Two tests were also performed according to japanese standard JIS K2514 ("ISOT Test", "INDIANA STIRRING Oxidation Test (indiana agitation Oxidation Test)" acronym), which confirmed the results detailed above.

Claims

1. Use of a lubricant composition comprising at least one base oil and at least one saturated or unsaturated, linear or branched fatty alcohol containing 8 to 20 carbon atoms for lubricating moving parts in screw compressors.

2. The method of claim 1, wherein the one or more fatty alcohols are selected from the group consisting of decyl alcohol, lauryl alcohol, palmityl alcohol, myristyl alcohol, stearyl alcohol, 2-hexyldecanol, 2-octyldodecanol, and mixtures thereof, preferably selected from the group consisting of lauryl alcohol, 2-hexyldecanol, 2-octyldodecanol, and mixtures thereof.

3. The use as claimed in any one of the preceding claims, wherein the lubricant composition has a content of the one or more fatty alcohols of less than or equal to 10% by weight, in particular from 0.01% to 10% by weight, more in particular from 0.02% to 8% by weight, preferably from 0.05% to 5% by weight, more preferably from 0.1% to 1% by weight, relative to the total weight of the lubricant composition.

4. The use according to any one of the preceding claims, wherein the lubricant composition comprises 80% to 99.5% by weight, in particular 90% to 99% by weight, preferably 95% to 99% by weight, relative to the total weight of the lubricant composition, of one or more base oils, preferably selected from Group II base oils, Group III base oils, Group IV base oils, Group V base oils and mixtures thereof, preferably selected from Group II base oils and/or Group III base oils, more preferably selected from Group II base oils.

5. The use as claimed in any one of the preceding claims, wherein the lubricant composition comprises at least one base oil selected from polyalphaolefins, esters of carboxylic acids and alcohols and mixtures thereof.

6. The use according to any one of the preceding claims, wherein the lubricant composition further comprises one or more additional additives selected from anionic compounds comprising a lipophilic long hydrocarbon chain and a hydrophilic head, anti-wear additives, extreme pressure additives, antioxidants, pour point depressant (PPD) additives, defoamers, demulsifiers, corrosion inhibitors, metal deactivators, cycloparaffinic solvents and mixtures thereof.

7. The use as claimed in any one of the preceding claims, wherein the screw compressor is a screw compressor for producing compressed air.

8. Use as claimed in any one of the preceding claims for reducing the formation of deposits and/or varnish in the screw compressor.

9. Use of at least one saturated or unsaturated, linear or branched fatty alcohol comprising 8 to 20 carbon atoms in a lubricant composition comprising at least one base oil for improving the properties of said composition when used in a screw compressor.

10. Use according to the preceding claim for improving the dispersion-maintaining properties of the composition used in screw compressors.

11. The method according to claim 9 or 10, for increasing the service life of the composition in the screw compressor, in particular for extending the interval between two consecutive oil changes of the screw compressor, more particularly such that the interval between two consecutive oil changes of the screw compressor is at least 2000 hours, preferably at least 4000 hours, more preferably at least 8000 hours, or even at least 12000 hours of operation of the screw compressor.

12. The use according to any one of claims 9 to 11, wherein the one or more fatty alcohols, the one or more base oils, the screw compressor and/or the composition are as defined in any one of claims 1 to 7.