阅读说明：本技术 含有基于r-10-羟基十八烷酸的金属皂和金属络合皂的润滑脂 (Grease containing metal soap and metal complex soap based on R-10-hydroxyoctadecanoic acid ) 是由 托马斯·李特斯 弗洛里安·哈恩 罗尔夫·路德 马库斯·乌尔班 安吉拉·罗宾 于 2020-04-24 设计创作，主要内容包括：本发明涉及碱金属皂基和/或碱土金属皂基和基于R-10-羟基十八烷酸的金属络合皂基的润滑脂及其应用。(The invention relates to a grease of an alkali metal soap base and/or an alkaline earth metal soap base and a metal complex soap base based on R-10-hydroxyoctadecanoic acid and the use thereof.)

1. A grease composition comprising:

a) at least one base oil, at least one oil,

b) at least one additive selected from the group consisting of,

c) at least one thickener, wherein the at least one thickener is a metal soap and/or a metal complex soap consisting of at least one alkali metal ion and/or alkaline earth metal ion and at least one carboxylic acid salt, wherein the carboxylic acid salt consists of C16-to C18-fatty acids, wherein the C16-to C18-fatty acids comprise at least R-10-hydroxystearic acid and the 10-hydroxyoctadecanoic acid has an enantiomeric purity of more than 80 wt.%, preferably more than 90 wt.%, in particular more than 98 wt.%, relative to the R-isomer.

2. Grease composition according to claim 1, wherein the CI 6-to C18-fatty acids comprise more than 50 wt.%, preferably more than 80 wt.%, in particular more than 95 wt.% 10-hydroxystearic acid.

3. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise palmitic acid, in particular more than 0.5 wt.%, preferably more than 1.0 wt.%, particularly preferred more than 1.0 wt.%

4. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise hydroxyhexadecanoic acid, in particular 9-hydroxyhexadecanoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferably more than 0.5 wt.%

5. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise octadecanoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferred

6. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise octadecenoic acid, in particular (9Z) -octadec-9-enoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferred more than 0.5 wt.%

7. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise octadecadienoic acid, in particular (9Z,12Z) -octadeca-9, 12-dienoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferably more than 0.2 wt.%

8. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise less than 1 wt.% of 12-hydroxy-9-octadecenoic acid, in particular (9Z,12R) -12-hydroxy-9-octadecenoic acid, preferably less than 0.2 wt.%.

9. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise less than 1 wt.% 12-hydroxyoctadecanoic acid, in particular less than 0.2 wt.%.

10. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids comprise hydroxy substituted C16-to C18-fatty acids, which hydroxy substituted C16-to C18-fatty acids are obtained from the enzymatic conversion of the corresponding unsaturated C16-to C18-fatty acids.

11. Grease composition according to at least one of the preceding claims, wherein the C16-to C18-fatty acids are obtained from an edible oil, in particular a waste edible oil, or biodiesel, comprising at least one enzymatic conversion.

12. The composition according to at least one of the preceding claims, wherein the metal soap or metal complex soap is:

-lithium soaps or lithium complex soaps or

-lithium/calcium soap or lithium/calcium complex soap, or

-calcium soaps or calcium complex soaps.

13. Grease composition according to at least one of the preceding claims, wherein the complexing agent is selected from:

-an alkali metal salt and/or an alkaline earth metal salt comprising:

a) saturated or unsaturated monocarboxylic acids or havingIn particularAlkali metal salt and/or alkaline earth metal salt of hydroxycarboxylic acid having carbon atom(ii) a Or

b) Has the advantages ofIn particularAlkali metal salts and/or alkaline earth metal salts of dicarboxylic acids of carbon atoms, optionally substituted if necessary; and/or

Alkali metal salts and/or alkaline earth metal salts of boronic and/or phosphoric acids, in particular with LiOH and/or Ca (OH)₂Or reaction products of alkali metal hydroxides or alkaline earth metal hydroxides, in particular LiOH and/or Ca (OH)₂Reaction products with borates or phosphates, and/or

-hasCarbon atoms, preferablyBorates and phosphates of straight or branched alkyl groups of carbon atoms.

14. The composition according to at least one of the preceding claims, wherein the composition comprises:

a)in particularOrThe base oil of (a) to (b),

b)in particularSaid additive of (a), and

c1)said metal soap of (1), preferablyOr

c2)Said metal complex soap of (1) comprisesPreferably comprises a complexing agentThe complexing agent of (1).

15. Grease composition according to at least one of the preceding claims, wherein the grease composition comprises a saturated or unsaturated monocarboxylic acid or hasAnd/orFurther metal soaps of hydroxycarboxylic acids having carbon atoms and/or further metal complex soaps, the metal complex soap monocarboxylic acids optionally comprising a complexing agent, wherein the proportion of the further metal soaps in the total metal soaps and/or metal complex soaps is preferably less than 50 wt.%, particularly preferably less than 20 wt.%.

16. Grease composition according to at least one of the preceding claims, wherein the grease composition further contains a co-thickener selected from one or more of aluminosilicates, alumina, hydrophobic and hydrophilic silicates, polymers, diurea/polyurea polyurethane and polytetrafluoroethylene.

17. Grease composition according to at least one of the preceding claims, wherein the composition has a viscosity at 25 ℃ determined according to ISO 2137Penetration value of (2), preferably

18. Grease composition according to at least one of the preceding claims, wherein the base oil has a kinematic viscosity at 40 ℃ ofPreference is given to

19. Grease composition according to at least one of the preceding claims, wherein the additive has one or several components selected from the group:

antioxidants, such as amine compounds, phenolic compounds, sulphur antioxidants, zinc dithiocarbamates or zinc dithiophosphates;

high-pressure additives, such as organochlorine compounds, sulfur, phosphorus or calcium borates, zinc dithiophosphates, organobismuth compounds or molybdenum compounds;

-polyols, fatty acids, fatty acid esters, animal oils orA vegetable oil;

preservatives, such as petroleum sulfonate, dinonylnaphthyl sulfonate or sorbitol esters;

metal deactivators, such as benzotriazole or sodium nitrite;

viscosity modifiers, such as polymethacrylates, polyisobutenes, oligo-1-decenes and polystyrenes;

-wear protection additives, such as molybdenum dialkyldithiocarbamates or molybdenum sulfur dialkyldithiocarbamates, aromatic amines;

friction modifiers, such as functional polymers, for example oleamides, polyether-and amido-based organic compounds or molybdenum dithiocarbamates; and

solid lubricants, for example polymer powders, such as polyamides, polyimides or polytetrafluorethylene chloride, graphite, metal oxides, boron nitride, lignin derivatives, for example lignosulphonates, organosolv lignin, metal sulfides, for example molybdenum disulfide, tungsten disulfide or mixed sulfides based on tungsten, molybdenum, bismuth, tin and zinc, inorganic salts of alkali metals and alkaline earth metals, for example calcium carbonate, sodium phosphate and calcium phosphate.

20. Use of a grease composition according to at least one of claims 1 to 19 for lubricating gears, constant velocity drive shafts, sliding and rolling bearings, sliding guide rails, spindle drives, linear drives, ball screw drives, in particular at minimum use temperatures of less than-20 ℃ and/or in automobiles, airplanes, unmanned planes or helicopters.

21. Use of a grease composition according to at least one of claims 1 to 19 for lubricating steering systems, sunroofs, window lifters, side mirror adjusters, door locks, landing gear wheel bearings, in particular in automobiles, airplanes, drones or helicopters.

22. Use of a grease composition according to at least one of claims 1 to 19 for lubricating a bearing of an electric motor, in particular in a hybrid vehicle or a pure electric vehicle.

23. A process for preparing a grease composition according to at least one of claims 1 to 19, by adding:

a) at least one base oil, at least one oil,

b) at least one additive selected from the group consisting of,

c) at least one thickener, wherein the at least one thickener is a metal soap or metal complex soap consisting of alkali metal ions or alkaline earth metal ions and R-10-hydroxystearic acid, wherein the metal soap or metal complex soap is preferably prepared in the base oil under heating to at least 170 ℃, and further preferably the additive is added when cooling below 100 ℃.

Technical Field

The invention relates to a grease of an alkali metal soap base and/or an alkaline earth metal soap base and a metal complex soap base based on R-10-hydroxyoctadecanoic acid and the use thereof.

Background

For many technical applications or tribological systems, it is important to use lubricants to reduce friction and wear on the contact surfaces of moving parts. In this case, lubricants of different consistencies can be used depending on the field of application. Lubricating oils have a liquid, flowable consistency, while greases have a semi-solid to solid (often gel-like) consistency. The characteristic feature of the grease is that the liquid oil component is absorbed and adhered by the thickener component. The pasty nature of the grease and its spreadable and easily plastically deformable nature, together with the viscous nature of this, ensure that the grease wets the lubrication point and exhibits a lubricating effect on surfaces subjected to frictional stress.

Greases contain a thickener that is uniformly distributed in a base oil. Additional adjuvants, such as emulsifiers, are also commonly used to stably disperse the thickener in the base oil. Various substances are known as base oils. Organic and inorganic compounds are used as thickeners. Furthermore, additives and the like are often added to greases in order to improve wear protection, frictional behavior, aging stability and corrosion protection.

The flow point and the shear viscosity are among the most important viscoelastic properties of the grease. Both of these have a large effect on the efficiency of drives or bearings lubricated with grease, especially in the presence of elastohydrodynamic lubrication (EHL) where the sliding or rotational speed is high. Especially at low application temperatures, the flow point and the shear viscosity have a great influence on the so-called breaking torque and running torque of components and assemblies lubricated with grease.

Greases are widely used for lubrication in the automotive and aerospace industries. They have many advantages over oils in terms of design and maintenance. They are therefore used to lubricate a large number of moving parts in cars and airplanes where the lubrication fails.

The viscoelastic behaviour of greases also has disadvantages, which are seen in particular when the lubricated parts are operated at very low temperatures. The "breaking torque" is particularly pronounced when starting a vehicle at very low temperatures (winter, arctic regions) in the case of vehicle components which have to be operated manually or lubricated with grease with low servo electrical drive power, such as steering systems, sunroofs, window lifters, side mirror regulators or door locks. In the automotive industry, therefore, greases must generally operate reliably at temperatures of at least-40 ℃. In the aeronautical field, greases must work reliably at temperatures as low as-54 ℃, sometimes even as low as-73 ℃. The grease in the landing gear wheel bearings is not allowed to fail during landing even if the aircraft is at altitude for a long period of time and the landing gear is exposed to very low temperature conditions. The "breaking torque" of the aviation grease is not allowed to be greater than a specific value.

In this case, the design of the maximum torque of components lubricated with grease, such as gears, sliding bearings or rolling bearings, and of all other types of sliding pairs, is generally dependent on the nature of the grease used for lubrication. Low flow point and shear viscosity at low temperatures can result in reduced breaking and running torque and allow designers to select components with relatively low drive power. In particular, this plays a major role in vehicles in which an electric drive is used, for example, in vehicles of hybrid vehicles or pure electric vehicles. Due to the use of greases, in particular low stick friction and sliding friction, at lower application temperatures, for example at-40 ℃, the reduced starting and running torques result in a smaller demand for electric drive power and for electric power, which on the one hand enlarges the range of battery-powered vehicles and on the other hand enables the use of power lines with a smaller cross-sectional area, thus enabling a reduction in weight on the power grid side of the vehicle.

The lubricating grease with high practical value can be created according to the lubricating requirement and the equipment requirement by abundant practical experience.

Hydroxyoctadecanoic acid, in particular 12-hydroxyoctadecanoic acid (12-hydroxystearic acid), is a fatty acid which has been used for a long time for the preparation of metal soap greases, in particular lithium soap greases and lithium complex soap greases. The starting products of 12-hydroxyoctadecanoic acid or esters or triglycerides thereof are ricinoleic acid ((9Z,12R) -12-hydroxy-9-octadecanoic acid) and triglycerides thereof, the so-called castor oil, which is obtained mainly from castor oil. For this purpose, the unsaturated hydroxy fatty acids ricinoleic acid or their triglycerides are converted into saturated hydroxy fatty acids by hydrogenation, in order to render them storage-stable and more thermally stable. To date, other hydroxyoctadecanoic fatty acids, such as 10-hydroxyoctadecanoic acid, have little technical significance, even if they are always additionally cited in intellectual property rights, but have not been used in practice.

Disclosure of Invention

In particular when preparing lithium greases, and in the case of metal soap greases based on 12-hydroxyoctadecanoic acid, a relatively high content of metal soap is required as thickener to obtain the desired consistency. As a result, such greases may result in increased friction losses in rolling bearing and gear applications or other tribological systems employing grease lubrication. The object of the invention is to reduce the disadvantages described above with regard to efficiency and low-temperature performance.

This object is achieved by the subject matter of the independent claims. Preferred embodiments are subject matter of the dependent claims or are described below.

The grease composition according to the present invention comprises

a) At least one base oil, at least one oil,

b) at least one additive selected from the group consisting of,

c) at least one thickener, wherein the at least one thickener is or comprises a metal soap and/or a metal complex soap formed from at least one alkali metal ion and/or alkaline earth metal ion and at least one carboxylic acid salt, wherein the carboxylic acid salt is composed of C16 to C18-fatty acids, wherein the C16 to C18-fatty acids comprise at least one 10-hydroxyoctadecanoic acid (R-10 hydroxystearic acid) and the 10-hydroxyoctadecanoic acid has an enantiomeric purity of more than 80 wt.%, preferably more than 90 wt.%, in particular more than 98 wt.%, relative to the R-isomer, wherein when a metal complex soap is used, it comprises a complexing agent (hereinafter referred to as metal soap and/or metal complex soap used according to the invention).

It was surprisingly found that enzymatically prepared R-10-hydroxyoctadecanoic acid with an enantiomeric purity of more than 80 wt.% shows particularly good thickener performance (100% ═ the sum of the R and S isomers). The 10-hydroxyoctadecanoic acid thus prepared, with a high R content, showed a significantly better (e.g. more than 50%) thickening effect than 12-hydroxyoctadecanoic acid in the same base oil and additive base.

10-Hydroxyoctadecanoic acid (10-hydroxystearic acid, CAS 638-26-6) can be prepared enzymatically, as has been published by G.Schroepfer in biochemistry (1966), 241 (22). Both R-form and S-form can be used for grease preparation.

The structural form of the R type is:

the substrate for the enzymatic conversion is mainly (9Z) -octadec-9-enoic acid (oleic acid), which can be made from the homemade "high oleic" sunflower oil, for example (9Z) -octadec-9-enoic acid with a purity of more than 92%, but also from a technical quality point of view from (9Z) -octadec-9-enoic acid with an industrial purity of more than 60%. By-products of this quality are, for example, hexadecanoic acid (palmitic acid), hexadecenoic acid (palmitoleic acid), octadecanoic acid (stearic acid) or polyunsaturated fatty acids, such as linoleic acid ((9Z,12Z) -octadeca-9, 12-dienoic acid) or linolenic acid ((9Z,12Z,15Z)) -octadeca-9, 12, 15-trienoic acid).

The advantage of this enzymatic process is the use of domestic raw materials, extending the supply chain to the local starting material. In addition to, for example, "high oleic" sunflower oil, it has also been proposed to use carbon-rich waste streams containing unsaturated C18 acids or esters to produce 10-hydroxyoctadecanoic acid. In particular, the carbon-rich waste stream may be used on the one hand as a nutrient for the production of enzymes and on the other hand as "feed" for the target product. For example, waste edible and used oils, residues from biodiesel production (e.g., glycerol, fatty acids, methyl esters) and other industrial by-pass streams are used as base stocks for material use.

12-Hydroxyoctadecanoic acid (12-hydroxystearic acid, CAS 106-14-9) is commercially available from Sigma-Aldrich or Nidera B.V. company. 12-hydroxyoctadecanoic acid is chemically prepared from castor oil by hydrolysis and hydrogenation. Castor oil is produced mainly in india, brazil and china. The purity of the commercially available 12-hydroxyoctadecanoic acid is generally within

Good thickening effect of R-10-hydroxyoctadecanoic acid is also imparted when other fatty acids with chain lengths of C16 to C18, for example hexadecanoic (palmitic) acid (CI 6: 0) 9-hydroxyhexadecanoic acid, octadecanoic (stearic) acid, (9Z) -octadec-9-enoic (oleic) acid or polyunsaturated fatty acids, such as linoleic ((9Z,12Z) -octadec-9, 12-dienoic) or linolenic acid ((9Z,12Z,15Z)) -octadec-9, 12, 15-trienoic acid), are further used in unhydroxylated or hydroxylated form in the production of metal soaps, in particular together with R-10-hydroxyoctadecanoic acid.

Preferably, the C16-to C18-fatty acids used for the preparation of the metal soaps and/or metal complex soaps used according to the invention have the individual or common characteristics shown below:

the-C16-to C18-fatty acids comprise more than 50 wt.%, preferably more than 80 wt.%, in particular more than 95 wt.% of 10-hydroxystearic acid.

-C16-to C18-fatty acids comprise palmitic acid, in particular more than 0.5 wt.%, preferably more than 1.0 wt.%, particularly preferably

-C16-to C18-fatty acids comprise hydroxyhexadecanoic acid, in particular 9-hydroxyhexadecanoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferably

-C16-to C18-fatty acids comprise octadecenoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferably

-C16-to C18-fatty acids comprise octadecenoic acid, in particular (9Z) -octadec-9-enoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, preferably

-C16-to C18-fatty acids comprise octadecadienoic acid, in particular (9Z,12Z) -octadeca-9, 12-dienoic acid, in particular more than 0.2 wt.%, preferably more than 0.5 wt.%, particularly preferably more than 0.2 wt.%

-C16-to C18-fatty acids comprise less than 1 wt.% of 12-hydroxy-9-octadecenoic acid, in particular (9Z,12R) -12-hydroxy-9-octadecenoic acid, preferably less than 0.2 wt.%.

-C16-to C18-fatty acids contain less than 1 wt.% 12-hydroxyoctadecanoic acid, in particular less than 0.2%.

-hydroxy-substituted C16-to C18-fatty acids are obtained from the enzymatic conversion of the corresponding unsaturated C16-to C18-fatty acids.

-C16-to C18-fatty acids are obtained from edible oils, in particular waste edible oils and/or biodiesel, comprising at least one enzymatic transformation.

The metal soaps and/or metal complex soaps used according to the invention are in particular

-lithium soaps or lithium complex soaps or

-lithium/calcium soap or lithium/calcium complex soap, or

-calcium soaps or calcium complex soaps.

It was surprisingly found that greases based on R-10-hydroxyoctadecanoic acid have significantly less thickener content at the same consistency and preferably require at least 30 wt.% thickener and at least 30 wt.% lithium hydroxide monohydrate for production.

The greases prepared in this way have, in particular at low temperatures, a significantly lower flow pressure, a lower flow point and a significantly lower starting torque in sliding bearings, rolling bearings and gearboxes. In the particular case of lithium soap and lithium complex soap greases, manufacturing costs can be saved by reducing the use of lithium hydroxide monohydrate.

For this reason, in the case of greases thickened with lithium soaps, the expense incurred by using lithium salts can be significantly reduced when R-10-hydroxyoctadecanoic acid is used instead of 12-hydroxyoctadecanoic acid, since up to 62% less lithium hydroxide monohydrate is required to form the lithium-hydroxyoctadecanoic acid soap. This is an important cost factor for grease preparation, especially in the context of battery production and increased lithium demand for electric vehicles.

The lithium R-10-hydroxyoctadecanoate soap is preferably prepared in situ, i.e. by reacting lithium hydroxide monohydrate with R-10-hydroxyoctadecanoic acid, but it is also possible to mix lithium 10-hydroxyoctadecanoate, prepared in a separate step, into the base oil and thicken it by subsequent thermal and mechanical processing.

It can also be demonstrated that the sliding friction coefficient of a grease based on R-10-hydroxyoctadecanoic acid is lower than a comparable grease based on 12-hydroxyoctadecanoic acid, for example at most 37% lower, in the presence of steel/steel contact.

Detailed Description

According to the inventionComposition comprising a metal oxide and a metal oxideAt least comprises the following steps:

a) preference is given toIn particularPreferably a base oil such as a polyalphaolefin, mineral oil and/or ester,

b) preference is given toIn particularThe additive (a) of (b),

c) thickener, wherein the thickener is or comprises a metal soap or a metal complex soap comprising an R-10-hydroxyoctadecanoic acid metal soap, the metal soap used according to the invention or the metal complex soap used according to the invention (which in turn has a complexing agent) content preferably beingPreference is given to(relative to metal soaps) or(in contrast to metal complex soaps) which comprisePreferably comprises a complexing agentAnd the metal soap salt used for the preparation is a metal hydroxide from alkali metal and/or alkaline earth metal hydroxides (metal soap used according to the invention).

wt.% refers to the sum of the compositions and applies in any case independently of one another.

Conventional lubricating oils which are liquid at room temperature are suitable as base oils. In particular, the base oils have a kinematic viscosity at a temperature of 40 ℃ in each case ofPreference is given to

The base oil may be classified as mineral oil or synthetic oil. Classified according to API-I, naphthenic and paraffinic mineral oils are referred to as mineral oils. Classified according to API-II, III +, also chemically modified mineral oils with very low aromatics and sulphur content, with very low amounts of saturates and with viscosity/temperature properties superior to those of group I oils and synthetic oils (GTL oils) from natural gas using the so-called gas-to-liquid conversion process are suitable.

Diethers or polyethers, esters, polyalphaolefins, polyethylene glycols and alkylaromatics and mixtures thereof are known as synthetic oils. The diether compound can be a compound having an aliphatic residue and/or an aromatic residue (e.g., an alkylated diphenyl ether). The polyether compounds may have free hydroxyl groups, but may also be completely etherified or have end groups esterified and/or prepared by starting with one or several hydroxyl and/or carboxyl groups (-COOH). If desired, it is also possible to alkylate the diphenyl ethers or polyphenylene ethers, preferably as the sole component or as a mixed component. Aromatic dicarboxylic acids, tricarboxylic acids or tetracarboxylic acids andesters of one or more of the alcohols, adipic acid, sebacic acid, trimethylolpropane, neopentyl glycol, pentaerythritol or dipentaerythritol with aliphatic branched or unbranched, saturated or unsaturated compoundsEsters of carboxylic acids, and ofBoth C18 dimer and complex esters of alcohols are suitable for use as the sole component or in any mixture.

Particularly suitable base oils are or comprise polyalphaolefins, which are obtainable, for example, from polymerization reactions, if necessary using metallocene catalysts, C4-and C14-LAO (LAO ═ linear alpha-olefins), C6-and C16-LAO, C8-, C10-and C12-LAO, C8-and C14-LAO, C6-, C10-and C14-LAO, C4-and C12-LAO as copolymers or as mixtures of the corresponding homopolymers.

Furthermore, it has been found that unlike conventional 12-hydroxyoctadecanoic acid metal greases, greases based on R-10-hydroxyoctadecanoic acid metal esters, in particular containing or consisting of polyalphaolefins in the base oil, have unexpected advantages in terms of low temperature performance and efficiency. The soaps used according to the invention differ significantly from conventional 12-hydroxyoctadecanoate soaps in these properties.

Optionally, in addition to the C16-to C18 fatty acids described above, other fatty acids may also be reacted with metal salts, such as metal hydroxides, to obtain other metal soaps. Here, it may be one or more alkali metal salts or alkaline earth metal salts (with a saturated or unsaturated monocarboxylic acid)And/orCarbon atoms) which, if desired, can be substituted into the preferably corresponding hydroxycarboxylic acids. Suitable carboxylic acids are, for example, lauric acid, myristic acid or behenic acid. Removing deviceAs mentioned straight chain fatty acids, saturated or unsaturated branched fatty acids may also be used. Naphthenic acids, tertiary decanoic acids or similar neo-acids may also be used.

Simple soaps, mixed soaps or complex soaps based on aluminum, bismuth, titanium and carboxylic or lithium salts, sodium salts, magnesium salts, calcium salts, aluminum, bismuth, titanium and sulfonic acids can also be added as further metal soaps or subsequently as additives in the preparation of the base oils. Alternatively, the soap may also be formed in situ when preparing the metal soaps used according to the invention.

In the preparation of various metal soaps, it is possible to use, instead of the fatty acids with free acid groups, the corresponding lower alcohol esters with saponification, for example the corresponding triglycerides and the methyl, ethyl, propyl, isopropyl or sec-butyl esters of the acid/hydroxy acids, in order to achieve better dispersion.

In the embodiment as metal complex soap, a complexing agent is used in addition to the metal soaps already described in the preparation process. The complexing agent in the sense of the invention is:

(a) saturated or unsaturated monocarboxylic acids or havingIn particularAlkali metal salts and/or alkaline earth metal salts of hydroxycarboxylic acids having carbon atoms or ofIn particularAlkali metal salts and/or alkaline earth metal salts, if necessary, of dicarboxylic acids having carbon atoms, respectively, being substituted, and/or

(b) Alkali metal salts and/or alkaline earth metal salts of boric acid and/or phosphoric acid, in particular with LiOH and/or Ca (OH)₂Or from alkali metal hydroxides or alkaline earth metal hydroxidesIn particular LiOH and/or Ca (OH)₂Reaction products with borates or phosphates, and/or

(c) Has the advantages ofCarbon atoms, preferablyBorates and phosphates of straight or branched alkyl groups of carbon atoms.

The complexing agent (a) is preferred.

Acetic acid and propionic acid are particularly suitable as monocarboxylic acids. Hydroxybenzoic acids such as p-hydroxybenzoic acid, salicylic acid, 2-hydroxy-4-ethylbenzoic acid, m-hydroxybenzoic acid, 2, 5-dihydroxybenzoic acid (gentisic acid) or 2, 6-dihydroxybenzoic acid (. gamma. -isophthalic acid) or 4-hydroxy-4-methoxybenzoic acid. Adipic acid (C)₆H₁₀O₄) Sebacic acid (C)₁₀H₁₈O₄) Azelaic acid (C)₉H₁₆O₄) And/or 3-tert-butyl-adipic acid (C)₁₀H₁₈O₄) Particularly suitable as dicarboxylic acids.

For example, metaborates, diborates, tetraborates or orthoborates, such as mono-lithium orthoborate, can be used as borate (b). Possible phosphates are alkali metal (preferably lithium) and alkaline earth metal (preferably calcium) -dihydrogen phosphate, -hydrogen phosphate, or-pyrophosphate, or calcium/lithium hydroxyapatite. Having a linear or branched alkyl group, havingPreferablyThose of carbon atoms can be used as esters of boric acid and phosphoric acid.

Optionally, bentonites, such as montmorillonites, the sodium ions of which are exchanged or partially exchanged, if necessary by organically modified ammonium ions, aluminosilicates, aluminum oxides, hydrophobic and hydrophilic silicic acids, oil-soluble polymers (for example polyolefins, poly (meth) acrylates, polyisobutenes, polybutenes or polystyrene copolymers), polyureas or polyurea-polyurethanes or polytetrafluoroethylene can additionally be used as co-thickeners. Bentonite, aluminosilicate, alumina, silicic acid and/or oil-soluble polymers may be added to prepare the base grease or later added as additives in the second step.

The lignin derivatives can also be added as co-thickeners or additives during or after the preparation of the metal soaps or metal complex soaps. Lignin derivatives are effective components in greases and can be used to improve wear protection and bond bearing properties.

In this case, the lignin derivative may represent a multifunctional component. Owing to their large number of polar groups and aromatic structures, their polymer structure and their extremely low solubility in all types of lubricating oils, the pulverulent lignins and/or lignosulfonates are also suitable as solid lubricants for greases and lubricating pastes. In addition, the phenolic hydroxyl group contained in lignin and lignosulfonate ensures the aging-inhibiting effect. In the case of lignosulphonates, the sulphur content of the lignosulphonate contributes to the EP/AW effect in the grease. Preferably lignin and/or calcium lignosulphonate and/or sodium lignosulphonate or mixtures thereof are used. But also lignin sulphate, soda lignin or organosolv lignin may be used. It is also possible to add biobased oligomers or polymers as solid lubricants or co-thickeners, such as triterpenes, cellulose or modified cellulose, chitin and/or chitosan.

In particular, thickeners (metal soaps according to the invention, further metal soaps and co-thickeners) are used, so that the composition contains sufficient thickener such that a penetration value (penetration) of10 (at 25 ℃), preferably 10 (at 25 ℃) (determined according to DIN ISO 2137 or ASTM D0217-97).

Furthermore, the compositions according to the invention comprise, if necessary, additives as additives. Customary additives in the sense of the present invention are antioxidants, wear protectors, corrosion protectors, detergents, colorants, lubricity improvers, adhesion enhancers, viscosity additives, friction modifiers, high-pressure additives and metal deactivators.

For example, it is:

primary antioxidants, such as amine compounds (e.g. alkylamines or 1-anilinonaphthalenes), aromatic amines, such as phenylnaphthylamine or diphenylamine or polymeric hydroxyquinolines (e.g. TMQ), phenolic compounds (e.g. 2, 6-di-tert-butyl-4-methylphenol), zinc dithiocarbamates or zinc dithiophosphates;

secondary antioxidants, such as phosphites, for example tris (2, 4-di-tert-butyl) phenyl phosphite or bis (2, 4-di-tert-butyl) -pentaerythritol diphosphite;

high-pressure additives, such as organochlorine compounds, sulfur or organic sulfur compounds, phosphorus compounds, inorganic or organoboron compounds, zinc dithiophosphates, organobismuth compounds;

active substances for improving "oiliness", e.g.A polyol, fatty acid ester, or animal or vegetable oil;

preservatives, for example petroleum sulfonate, dinonylnaphthyl sulfonate or sorbitol esters; sebacic acid disodium salt, neutral or overbased calcium sulfonates, magnesium sulfonates, sodium sulfonates, calcium and sodium naphthalenesulfonates, calcium salicylate, amine phosphates, succinates, metal deactivators, such as benzotriazole or sodium nitrite;

viscosity modifiers, such as polymethacrylates, polyisobutylene, oligo-1-decene, polystyrene;

wear protection additives and friction modifiers, e.g. Organic Molybdenum Complexes (OMC), molybdenum-dialkyldithiophosphates, di-alkyl dithiophosphatesMolybdenum alkyldithiocarbamates or dialkyldithiocarbamates, especially molybdenum-dibutyldithiocarbamates and molybdenum dialkyldithiocarbamates (Mo)_2mSn (dialkyl carbamate)₂WhereinAnd is) Zinc dithiocarbamate or zinc dithiophosphate; or a trinuclear molybdenum compound corresponding to the formula:

Mo₃S_kL_nQ_z

wherein L is an independently selected ligand having an organic group with carbon atoms, as disclosed in US 6172013B 1, wherein n is from 1 to 4, k is from 4 to 7, Q is selected from the group of neutral electron donor compounds consisting of amines, alcohols, phosphines and ethers, and Z is in the range of 0 to 5 and includes non-stoichiometric values, with the aim of making the compound oil-soluble or oil-dispersible (see DE 102007048091);

friction modifiers, for example functional polymers, such as oleamides, polyether-based and amide-based organic compounds, such as alkylpolyethylene glycol tetradecylene glycol ether, polyisobutylene succinimide (PIBSI) or polyisobutylene succinic anhydride (PIBSA);

furthermore, the grease composition according to the invention also comprises conventional additives for corrosion resistance, oxidation resistance and protection against metal influences, which act as chelating compounds, radical scavengers, UV converters, reaction layer forming agents and the like. Additives to improve the hydrolysis resistance of the ester base oils, such as carbodiimides or epoxides;

usable as solid lubricants are, for example, polymer powders, such as polyamides, polyimides or polytetrafluorethylene chloride, melamine cyanurate, graphite, metal oxides, boron nitride, silicates, such as magnesium silicate hydrate (talc), sodium tetraborate, potassium tetraborate, metal sulfides, such as molybdenum disulfide, tungsten disulfide or mixed sulfides based on tungsten, molybdenum, bismuth, tin and zinc, inorganic salts of alkali metals and alkaline earth metals, such as calcium carbonate, sodium phosphate and calcium phosphate.

Carbon black or other carbon-based solid lubricants, such as nanotubes, may also be used. Furthermore, the lignin derivatives can be used as thickener components or solid lubricants. It may also be a bio-based oligomer or polymer, for example, a triterpene, a modified cellulose, chitin, chitosan or a polypeptide.

The grease according to the invention is particularly suitable for use in sliding and rolling bearings, gearboxes and/or constant velocity drive shafts in industrial and automotive applications. A particular aspect of the invention is the contact with low-friction greases, in particular at low temperatures, where the required breaking torque and running torque are low and low flow points and shear viscosities are advantageously shown. In the special case of lubricating sliding bearings, rolling bearings, gearboxes and/or constant-velocity drive shafts in automotive technology, therefore, smaller and lighter drives can be used and efficiency advantages can be achieved. In particular, the greases prepared according to the invention have a pour point at-35 ℃ which is reduced by up to 43% (determined according to DIN 51810-2 with a vibration rheometer) and a shear viscosity which is reduced by up to 50% (determined according to DIN 51810-1 with a shear viscometer) compared with the same greases. The greases prepared according to the invention show values at-40 ℃ which are at least 50% lower than those of the same grease when the flow pressure is tested according to DIN 51805-2. Furthermore, the grease according to the invention has a coefficient of sliding friction in the presence of steel/steel contact, which is as much as 37% lower than a comparable grease based on 12-hydroxyoctadecanoic acid.

Various laboratory test methods may be used to test the flow point and shear viscosity of the grease. The method used for determining the flow point by means of a vibrating rheometer is DIN 51810-2. Furthermore, the flow pressure method according to DIN 51805-2 is also used to determine the lower limit of the service temperature of the grease. The flow pressure is the pressure difference from atmospheric pressure, which is required to force the grease bundle out of the test nozzle under the conditions specified by the standard. It is a measure of the stiffness of the grease at the respective test temperature and can be used in addition for testing in accordance with DIN 51810-2 as a measure of the flow point.

IP 186 and ASTM D1478 describe how to determine the starting torque and running torque of a ball bearing. The functionality of the grease can be tested by these test methods at low temperatures, for example at-40 ℃ or-73 ℃.

Thus, these testing methods are part of the numerous regulations specified by the automotive and aviation industries (both civil and military aviation) and by users. They have proven to be useful test methods for many years. DIN 51805-2, the fluid pressure method, is used as a national standard method, mainly in germany, to determine the lower limit of the use temperature of a grease.

For example, the preparation of the grease may be carried out as follows: the salt/metal compound is mixed into the carboxylic acid compound, which can be stretched by the base oil component (if desired), the complexing agent (if desired) is added, and the mixture is heated, if desired, to above 100 ℃, in particular to above 170 ℃ to form a thickened grease product, the grease product is cooled and, if desired, water is added, and shear forces are applied to the mixture, for example by means of a tooth colloid mill, a high-pressure homogenizer and/or three-roll chair. According to another embodiment of the invention, the thickener is synthesized in situ in the base oil in a closed reaction vessel (e.g. an autoclave) under pressure and at elevated temperature.

The grease composition may be used for lubricating gear boxes, constant velocity drive shafts, sliding and rolling bearings, sliding guide rails, spindle drives, linear drives, ball screw drives, in particular in cases where the minimum use temperature is less than-20 ℃ and/or in automobiles, airplanes, drones or helicopters. Other applications include lubricated steering systems, skylights, window lifters, side mirror adjusters, door locks, landing gear wheel bearings, particularly in automobiles, airplanes, drones, or helicopters. The grease composition is also suitable for lubricating motor bearings, in particular in hybrid or pure electric vehicles.

Experimental examples

Example A (reference)

Preparation of lithium 12-hydroxyoctadecanoate from poly-alpha-olefin

171g of polyalphaolefin (a mixture of PAO 6: PAO 150 ═ 3: 1) and 45.25g of 12-hydroxyoctadecanoic acid as a racemate were placed in a stirred reactor, and heated to 86 ℃. Then, 6.31g of lithium hydroxide monohydrate dissolved in advance in 25g of distilled water was added. Then, heat to 210 ℃, then cool to below 100 ℃ over 20 minutes, and add the additives.

Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further polyalphaolefin. The grease thus prepared had a thickener content of 12.13 wt.% and a penetration value of 3320.1 mm.

Examples B1, B2, B3 (according to the invention)

Preparation of lithium 10-hydroxyoctadecanoate from poly-alpha-olefin

171g of polyalphaolefin (a mixture of PAO 6 (metallocene base): PAO 150 ═ 3: 1) and 35.16g R-10-hydroxyoctadecanoic acid were placed in a stirred reactor and heated to 91 ℃. Then, 5.07g of lithium hydroxide monohydrate dissolved in advance in 21g of distilled water was added. Then, heat to 210 ℃, then cool to below 100 ℃ over 20 minutes, and add the additives. Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further polyalphaolefin. The greases thus prepared had a thickener content of 4.64 wt.% (B1), 4.97 wt.% (B2) and 5.06 wt.% (B3) and penetration values of 3390.1mm (B1), 3320.1mm (B2) and 3200.1mm (B3).

Example C (reference)

Preparation of lithium 12-hydroxyoctadecanoate from poly-alpha-olefin

171g of polyalphaolefin (a mixture of PAO 6: PAO 150 ═ 3: 1) and 45.25g of 12-hydroxyoctadecanoic acid as a racemate were placed in a stirred reactor, and heated to 91 ℃. Then, 6.31g of lithium hydroxide monohydrate dissolved in advance in 25g of distilled water was added. Subsequently, the mixture was heated to 210 ℃ and then cooled to 122 ℃ or lower within 15 minutes. Thereafter, 1.25g of tris (2-ethylhexyl) borate was added, cooled to below 100 ℃ and the additive was added. Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further polyalphaolefin. The grease thus prepared had a thickener content of 10.52%, a penetration value of 3280.1mm, and a dropping point of above 300 ℃.

Example D (invention)

Preparation of lithium R-10-hydroxyoctadecanoic acid complex ester from poly-alpha-olefin

171g of polyalphaolefin (a mixture of PAO 6: PAO 150 ═ 3: 1) and 35.16g R-10-hydroxyoctadecanoic acid were placed in a stirred reactor and heated to 91 ℃. Then, 5.07g of lithium hydroxide monohydrate dissolved in advance in 21g of distilled water was added. Then, the mixture was heated to 210 ℃ and cooled to 122 ℃ or lower within 15 minutes. Thereafter, 1.19g of tris (2-ethylhexyl) borate was added, cooled to below 100 ℃ and the additives were added. Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further polyalphaolefin. The grease thus prepared had a thickener content of 4.68 wt.%, a penetration value of 3350.1mm, and a dropping point of 293 ℃.

Example E (REFERENCE)

Preparation of 12-hydroxy lithium octadecanoate ester from mineral oil

107.48g of mineral oil, type II (40 ℃, kinematic viscosity 110 mm) are placed in a stirred reactor²S) and 22.08g of 12-hydroxyoctadecanoic acid (racemate) were heated to 91 ℃. Then, 3.18g of lithium hydroxide monohydrate dissolved in 15g of distilled water in advance was added. Then, the mixture was heated to 210 ℃ and then cooled to 100 ℃ or lower within 20 minutes, and the additives were added. Thereafter, the grease was homogenized with a three-roll mill and the class II SN 600 was adjusted to the desired consistency by continuous addition of further mineral oil. The grease thus prepared had a thickener content of 8.3% and a penetration value of 3170.1 mm.

Example F (inventive)

Preparation of 10-hydroxy lithium octadecanoate ester from mineral oil

107.12g of mineral oil, type II (40 ℃, kinematic viscosity 110 mm) are placed in a stirred reactor²S) and 22.04g R-10-hydroxyoctadecanoic acid, heated to 91 ℃. Then, 3.17g of lithium hydroxide monohydrate dissolved in 15g of distilled water in advance was added. Then, heat is appliedTo 210 c and then cooled to below 100 c over 20 minutes and the additives added. Thereafter, the grease was homogenized with a three-roll mill and the class II SN 600 was adjusted to the desired consistency by continuous addition of further mineral oil. The grease thus prepared had a thickener content of 4.21 wt.% and a penetration value of 3280.1 mm.

Example G (REFERENCE)

Preparation of 12-hydroxy lithium octadecanoate ester from ester oil

107.48g of pentaerythritol ester (40 ℃ C., viscosity 96 mm) were placed in a stirred reactor²S) and 22.08g of 12-hydroxyoctadecanoic acid, heated to 91 ℃. Then, 3.18g of lithium hydroxide monohydrate dissolved in 15g of distilled water in advance was added. Then, the mixture was heated to 210 ℃ and then cooled to 100 ℃ or lower within 20 minutes, and the additives were added. Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further pentaerythritol esters. The grease thus prepared had a thickener content of 6.13% and a penetration value of 3280.1 mm.

Example H (invention)

Preparation of R-10-hydroxy lithium octadecanoate ester by ester oil

107.12g of pentaerythritol ester (40 ℃ C., viscosity 96 mm) were placed in a stirred reactor²S), 22.04g R-10-hydroxyoctadecanoic acid, heated to 91 ℃. Then, 3.17g of lithium hydroxide monohydrate dissolved in 15g of distilled water in advance was added. Then, the mixture was heated to 210 ℃ and then cooled to 100 ℃ or lower within 20 minutes, and the additives were added. Thereafter, the grease was homogenized with a three-roll mill and adjusted to the desired consistency by continuous addition of further pentaerythritol esters. The grease thus prepared had a thickener content of 4.08 wt.% and a penetration value of 3350.1 mm.

The grease prepared with R-10-hydroxyoctadecanoic acid according to the invention showed a better thickening effect than 12-hydroxyoctadecanoic acid, 62% (at most) better than it, in the same base oil and additive matrix.

Examples table

1) R-10-hydroxyoctadecanoic acid with a purity of > 99%) R-10-hydroxyoctadecanoic acid with a purity of 91.5%, 8.5% octadecanoic acid

3) R-10-Hydroxyoctadecanoic acid with a purity of 91.5%, 8.5% octadecenoic acid

4) organic compounds containing nitrogen (N) group, phosphorus (P) group, sulfur (S) group, zinc (Zn) group, molybdenum (Mo) group

1) R-10-hydroxyoctadecanoic acid with a purity of > 99%) R-10-hydroxyoctadecanoic acid with a purity of 91.5%, 8.5% octadecanoic acid

3) R-10-Hydroxyoctadecanoic acid with a purity of 91.5%, 8.5% octadecenoic acid

4) organic compounds containing nitrogen (N) group, phosphorus (P) group, sulfur (S) group, zinc (Zn) group, molybdenum (Mo) group

5) total amount of lithium hydroxide monohydrate + fatty acid + complexing agent added

6) 12.7mm spheres on 3 surfaces (stock l00Cr6) with a surface pressure of 144N/mm for point contact²The sliding speed is 0.057m/s

5) total amount of lithium hydroxide monohydrate + fatty acid + complexing agent added

6) 12.7mm spheres on 3 surfaces (stock l00Cr6) with a surface pressure of 144N/mm for point contact²The sliding speed was 0.057 m/s.