CN111315853A

CN111315853A - Lubricant composition

Info

Publication number: CN111315853A
Application number: CN201880055345.3A
Authority: CN
Inventors: A·菲格; L·科格尔; T·阿萨姆; P·德根; C·福兰德
Original assignee: Karbem Ltd
Current assignee: Karbem Ltd
Priority date: 2017-07-21
Filing date: 2018-07-23
Publication date: 2020-06-19
Also published as: WO2019016412A1; EP3431574A1

Abstract

An aqueous base oil based lubricant composition, in particular a grease composition, comprises a thickener component formed from one or more thickeners or salts thereof and a polymer component formed from one or more natural or chemically modified polymers or salts thereof. The thickener may be obtained by combining a monocarboxylic or dicarboxylic acid or a mixture thereof with an alkanolamine, alkylamine or a mixture thereof.

Description

Lubricant composition

Technical Field

The present invention relates to a base oil for a lubricant composition, in particular a grease composition, and to a process for preparing such a lubricant composition.

Background

Greases typically consist of 65 to 95% base oil, 3 to 30% thickener component and 0 to 10% additives (Wilfried j.bartz: schmieerfette.zus amamesnetzung, eigneschaften, Pr ü tung undAnwendung, Expert2000, page 33.) the base oil in most cases consists of natural or synthetic oils such grease compositions are known, for example, from WO08154997a 1.

Disclosure of Invention

It has now surprisingly been found that the base oil used to prepare the lubricant composition can be aqueous. Preferably, it is aqueous and oil-free. In the simplest case, the base oil may consist of water. The base oil preferably comprises one or more polymers or salts thereof (polymer component). The chemical and/or physical properties, especially viscosity, of the base oil can be influenced by the polymer component and/or the ratio of the amounts of water to polymer component.

By preparing a lubricant composition using the base oil of the present invention, a lubricant composition having favorable electrical conductivity can be produced. Preferably, the inventive lubricants have an electrical conductivity of 10^-12To 10^-3S/cm, preferably in the range of 10^-9To 10^-3S/cm, particularly preferably 10^-7To 10^-3In the range between S/cm, especially 10^-5To 10^-3In the range between S/cm. This opens up the possibility of using the lubricant composition according to the invention, in particular the grease according to the invention, as a "bridge", and thus for example in rolling bearings in electrical machines. The lubricant composition of the invention may hereby be used as a conductive seal, as described for example in EP 0962675 a 2.

The aqueous base oils of the present invention additionally allow a reduction of the oil proportion in the lubricant composition, advantageously with a complete oil saving. In a particularly preferred embodiment, the base oils of the present invention and lubricant compositions prepared therewith are oil-free, especially mineral oil-free. Thus, the base oil and lubricant compositions of the present invention may preferably be used in: a possible leakage in the device will directly result in a contamination of the environment. This is particularly significant in the following applications: contamination of surface water is a concern in such applications. Accordingly, one particularly preferred field of use is the use of the lubricant compositions of the present invention in underwater applications, such as in underwater turbines.

The subject of the present invention is therefore a lubricant composition, preferably a grease composition, comprising water and a first component formed by one or more thickeners or salts thereof (thickener component), wherein the relative proportion of water is at most 70 wt.%, preferably at most 50 wt.%, particularly preferably at most 40 wt.%, very particularly preferably at most 35 wt.%, when the thickener component has a dropping point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃.

In contrast, when the thickener component has a melting point of more than 260 ℃, preferably more than 280 ℃, particularly preferably more than 300 ℃, the relative proportion of water is at most 40 wt.%, preferably at most 35 wt.%. Such thickeners are typically solids. These thickeners are added as solids to the base oil to prepare the grease composition. The lubricant composition thus prepared may be pasty. The lubricant composition obtained is then a paste, that is to say a solid dispersion in a liquid. The invention also relates to the use of the aqueous base oil for producing a grease composition and to a method for producing a lubricant composition, comprising the following steps:

(i) providing an aqueous base oil, preferably comprising a mixture of water and one or more water-soluble polymers or salts thereof (polymer component);

(iia) combining the base oil with the thickener component

(iii) Optionally, heating the mixture

(iv) Optionally, additives are added.

Herein, combining the thickener with the base oil may be performed by adding the thickener or by preparing the thickener in situ in the base oil.

In the sense of the present invention, "base oil" means a carrier medium, in particular a dispersant, which is suitable for receiving, in particular dispersing, the thickener components and optionally additives. The base oil itself has friction reducing properties. Due to its chemical composition and properties, the base oil may significantly affect the lubricating properties of the resulting lubricant composition, in particular a grease composition. In a preferred embodiment, the base oil comprises a polymeric component.

A "grease composition" is a semi-liquid to thick dispersion of a thickener component in a liquid carrier medium (especially a base oil). The grease composition can resist external forces that change shape. The grease composition has a yield limit. Preferably, the molecules in the grease composition have a higher order state than the molecules in the liquid lubricant composition.

A "thickener" is a substance that possesses the ability to form a three-dimensional network in a medium. Such a network can preferably consist of fibrous structural units (fibrils), which can consist in particular of crystallites and micelles. Such networks may be formed as molecular aggregates by association. Molecules of the base oil are preferably embedded into this three-dimensional network by molecular interactions, capillary forces and mechanical entrainment. The thickener may also be present as a salt. The term "thickener" also always includes salts thereof, as long as they are not explicitly mentioned.

The use of a thickener in the base oil preferably has the result that the grease composition has a defined yield limit. The reason for this is the three-dimensional network formed by the thickener molecules (due to physical interactions) as already described above, whereby the molecules of the base oil can be partially bound or embedded in a three-dimensional matrix.

"melting point" refers to the temperature at which the liquid and solid phases of a substance equilibrate at atmospheric pressure (1013 hPa). At the melting point, the substance preferably changes from a solid to a liquid state without undergoing a chemical change.

The "drop point" indicates the meltability of the solid fat, especially the lubricant. In the sense of the present invention, the dropping point is the temperature at which the lubricant drops under its own weight, in particular begins to flow, under test conditions (for example those of standard IP 396).

The term "polymer component" is understood to mean one or more water-soluble polymers or salts thereof. The term "polymer" always includes also salts of polymers, as long as they are not explicitly indicated otherwise here. By combining the polymer component with water, a thickened liquid having an increased viscosity compared to the viscosity of water can be obtained. In addition, the polymer, in particular the polymer component, may also have lubricating properties.

Advantageous embodiments of the invention are explained in detail below.

In a preferred embodiment of the grease composition according to the invention, the relative proportion of water is at least 10 wt.%, preferably at least 15 wt.%, particularly preferably at least 20 wt.%, very particularly preferably at least 30 wt.%, when the thickener component has a dropping point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at least 300 ℃.

Alternatively, in this embodiment, when the thickener component has a melting point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃, the relative proportion of water is at least 10 wt.%, preferably at least 15 wt.%, particularly preferably at least 20 wt.%, very particularly preferably at least 30 wt.%.

As already carried out, it is particularly advantageous for the base oil to comprise a polymer component. The relative proportion of the polymer component in the base oil is preferably from 0.05 to 15% by weight, preferably from 0.1 to 10% by weight, in particular from 0.1 to 5% by weight. This applies in particular when the polymer component is a cellulose ether or a salt thereof, in particular a sodium carboxymethyl cellulose salt.

It has further been shown that a grease composition with particularly advantageous properties may be obtained when the weight ratio of the polymer component to the thickener component in the grease composition is between 1:60 and 1:1, preferably between 1:40 and 1:3, especially between 1:30 and 1: 5.

In addition to the advantages obtained by adjusting the weight proportion of the polymer components, it is also advantageous if the relative proportion of the thickener components in the total composition is at least 20 wt.%, preferably at least 30 wt.%, further preferably at least 35 wt.%, very preferably more than 35 wt.%.

Particularly preferred grease compositions according to the invention are obtained with a relative proportion of water between 25 and 95 wt.%, a proportion of the polymer component between 0.5 and 4 wt.% and a proportion of the thickener component between 10 and 70 wt.%.

The base oil and, where base oil is used, the grease composition prepared preferably comprises a water-soluble polymer or salt thereof (polymer component) selected from the group consisting of:

a) natural polymers such as polysaccharides, inorganic polysaccharides, natural rubber and lignin;

b) chemically modified polymers such as cellulose ethers and modified starches;

c) synthetic polymers, e.g. polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone

Or mixtures thereof.

The term "natural polymer" (also referred to as "biopolymer") refers to a polymer whose origin is of biological origin and which does not comprise chemical modifications.

By "semi-synthetic polymer" is understood a chemically modified natural polymer. Examples are carboxyalkyl celluloses, such as carboxymethyl cellulose, hydroxyalkyl celluloses, such as hydroxypropyl cellulose, or cellulose acetate.

"synthetic polymer" refers to a polymer obtained by chemical synthesis/polymerization. Examples thereof are polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone and the like.

Preferably a natural polymer of the polymer component of the grease composition or a salt thereof may be selected. In particular, alginates, pectins, cellulose, gelatin and natural starches can be used.

Semisynthetic polymers or salts thereof have particularly advantageous properties in the base oil or grease composition and are therefore a particularly preferred embodiment of the present invention. Here, the semisynthetic polymer or salt thereof is selected from the following group of particular interest:

cellulose ethers and/or esters, in particular ethylcellulose, propylcellulose, carboxymethylcellulose (CMC), Hydroxypropylcellulose (HPC), Hydroxypropylmethylcellulose (HPMC) and cellulose acetate, especially preferably carboxymethylcellulose (CMC) or salts thereof, preferably sodium salts, or mixtures thereof. Very particular preference is given to the sodium salt of carboxymethylcellulose.

In a preferred embodiment of the present invention, the cation of the salt of carboxymethyl cellulose is selected from the group consisting of: metals of main group 1, 2, 3 or 4 or sub-group 12 or mixtures thereof.

In a particularly preferred embodiment, the following metals are selected from the group consisting of: li, Na, K, Ca, Ba, Al and/or Zn, particularly preferably from the group consisting of: li, Na, K and Ca.

In a particularly preferred embodiment, the sodium salt of carboxymethyl cellulose is Walocel CRT 1000 PA.

The preferred viscosity of the sodium salt of carboxymethyl cellulose is between 10 and 40,000mPa as a 2% solution in water. The molecular weight of the sodium carboxymethylcellulose is particularly preferably in the range from 90000g/mol to 700000g/mol,

in a preferred embodiment, the semi-synthetic polymer of the polymer component is selected from the group consisting of:

cellulose ethers, cellulose esters, or mixtures thereof.

In a particularly preferred embodiment, the thickener component is selected from the group consisting of: a soap thickener, a non-soap thickener, or a mixture thereof.

Soap thickeners and non-soap thickeners differ in the thickener component. A general description of thickeners which are known to the person skilled in the art for a long time can be found in t.goertz, Schmierfette auf Seifenbasis, zusumamensetzng-Herstellung-eignenschaften, Tribologie + schmierbechnik 56.jahrgan, 1/2009. In a particularly preferred embodiment, the thickener component of the grease composition of the present invention is selected from the group consisting of: metallic, complex or mixed soaps (which belong to the class of soap thickeners), non-soap thickeners are used in particular urea, clays such as bentonite, montmorillonite or bauxite, silicates, silicic acid, talc, polytetrafluoroethylene, metal salts, pigments or graphite. Each of these thickeners may be used alone or in combination.

The "soap thickener" in the grease composition is especially a metal soap or salt which may be formed by the reaction of a metal hydroxide with a fatty acid in the case of water dissociation. "metal hydroxide" is understood to mean a compound which consists of an ionic lattice in the solid state. Negative lattice building blocks or anions in the lattice consist of oxygen and hydrogen, in particular hydroxide ions (OH)^-). In contrast, positive lattice building blocks or cations, also referred to as lattices, are metals. In a preferred embodiment, it is a metal of main groups 1, 2, 3 and 4 and of sub-group 12.

"simple metal soaps" are produced here by reaction of metal hydroxides with fatty acids. In addition to free fatty acids, triglycerides can also be reacted with metal hydroxides, thereby producing soaps with mixed anions.

By contrast, "mixed metal soaps" is understood to mean mixtures of soaps having different metal ions, in particular cations, which can be generated by the reaction of two different metal hydroxides with fatty acids. The properties of such mixed soap lipids are more or less proportionally composed of the properties of simple metal soaps. It is preferred to use mixed metal soaps in order to improve the insufficient properties of certain soaps, for example by mixing with calcium soaps to improve the water resistance of lithium and sodium fats. The preparation is particularly preferably carried out in a one-stage process.

"complex soaps" are formed in particular by reaction of metal hydroxides with fatty acids and mineral acids (e.g. boric acid) or short-chain organic monocarboxylic acids (preferably acetic acid) or dicarboxylic acids (particularly preferably adipic acid, azelaic acid and sebacic acid).

"bentonite" is a clay-containing stone whose main part consists of a tri-layer silicate with swelling capacity, preferably montmorillonite. The bentonite may comprise, in addition to the main fraction, other associated minerals, in particular quartz, mica, feldspar or lime, in variable proportions. Bentonite as thickener is well known to the person skilled in the art (T.Goertz, Gel-und Bentonitfette-Zusammensetzng-Eigenschaften, Tribologie + Schmierungs-technik,56. Jahrgarg, 2/2009).

"silicic acid" is understood to mean the oxyacids of silicon. It is preferably monosilicic acid (Si (OH) in the sense of the present invention₄) Condensates of (b), especially polysilicic acid.

Soap thickeners are typically composed of one or more anions and one or more cations, whereby they are especially ionic compounds. In a preferred embodiment of the grease composition according to the present invention, the cation of the soap thickener is selected from the group consisting of: metals of main groups 1, 2, 3 and 4 and metals of sub-group 12. In a particularly preferred embodiment, the following metals are selected from the group consisting of: li, Na, K, Ca, Ba, Al and/or Zn, particularly preferably from the group consisting of: li, Na, K and Ca.

In another particularly preferred embodiment, the anion of the soap thickener is selected from the group consisting of: saturated C2 to C30 monocarboxylic and/or dicarboxylic acids, mono-or polyunsaturated C2 to C30 monocarboxylic and/or dicarboxylic acids, aromatic C5 to C30 monocarboxylic and dicarboxylic acids or mixtures of such carboxylic acids.

In a preferred embodiment, the anion of the soap thickener is selected from monocarboxylic acids. In another preferred embodiment, the anion of the soap thickener is selected from dicarboxylic acids. The anion is particularly preferably selected from a mixture of monocarboxylic and dicarboxylic acids.

The anion of the soap thickener is especially selected from the group consisting of: saturated C2 to C30 monocarboxylic and/or dicarboxylic acids, preferably C12 to C20 monocarboxylic and/or dicarboxylic acids, particularly preferably stearic acid, sebacic acid, adipic acid, oleic acid and azelaic acid or mixtures thereof.

The anion of the soap thickener is preferably selected from derivatives of monocarboxylic and/or dicarboxylic acids in addition to the corresponding monocarboxylic and/or dicarboxylic acids. Substituted monocarboxylic acid derivatives and/or dicarboxylic acid derivatives are also preferably selected, very particularly preferably stearic acid derivatives, oleic acid derivatives and/or sebacic acid derivatives, as anions for the soap thickener.

In a particularly preferred embodiment of the present invention, the monocarboxylic and/or dicarboxylic acids are in particular selected from the group consisting of: hydroxystearic acid and/or hydroxystearic acid derivatives, hydroxysebacic acid and/or hydroxysebacic acid derivatives, in particular from 12-hydroxystearic acid.

Thus, the term "carboxylic acid" herein includes carboxylic acids having substituted alkyl groups as well as carboxylic acid derivatives, in addition to unsubstituted carboxylic acids. Preferred substituents for alkyl groups herein are selected from the group consisting of: hydroxylates, halides, ethers, and amines. Preferred carboxylic acid derivatives are selected from the group consisting of: carboxylic acid amides, carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides.

In another embodiment, the anion of the soap thickener is selected from the group consisting of: inorganic acids, in particular boric acid or phosphoric acid.

In a preferred embodiment, the soap thickener in the grease composition may be obtained by combining a monocarboxylic and/or dicarboxylic acid (preferably those mentioned above) and an alkanolamine and/or alkylamine, preferably an alkanolamine, particularly preferably triethanolamine.

It has been shown that soap thickeners with particularly advantageous properties can also be obtained by combining a mixture formed from an alkanolamine and one or more metal hydroxides and the monocarboxylic and/or dicarboxylic acids of the invention (as already defined herein).

In a particularly preferred embodiment, the grease composition may be obtained by: the base oil comprising water and one and/or more cellulose esters, preferably carboxymethylcellulose and/or salts thereof, particularly preferably sodium carboxymethylcellulose, is combined with a thickener component which can be obtained by combining a mixture formed from alkanolamines, in particular triethanolamine, and one or more metal hydroxides, preferably selected from lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, in particular potassium hydroxide, and one or more monocarboxylic and/or dicarboxylic acids, preferably selected from stearic acid, 12-hydroxystearic acid, sebacic acid, oleic acid or mixtures thereof.

In a particularly preferred embodiment, the grease composition may be obtained by: the base oil consisting of water and sodium carboxymethylcellulose, the thickener component, which can be obtained by combining a mixture formed from triethanolamine, potassium hydroxide and stearic acid, are combined.

The grease composition of the present invention may additionally be obtained by: the base oil consisting of water and sodium carboxymethylcellulose is combined with a thickener component which can be obtained by combining a mixture formed from a metal hydroxide, in particular lithium hydroxide, sodium hydroxide, potassium hydroxide and/or calcium hydroxide, and a monocarboxylic and/or dicarboxylic acid, preferably stearic acid, a stearic acid derivative, terephthalic acid or a terephthalic acid derivative, sebacic acid or a sebacic acid derivative, adipic acid or an adipic acid derivative, azelaic acid or an azelaic acid derivative, oleic acid or an oleic acid derivative or mixtures thereof.

In a particularly advantageous embodiment, such a grease composition may be obtained by: a base oil comprising water and carboxymethylcellulose and/or salts thereof (especially sodium carboxymethylcellulose) is combined with a thickener component obtainable by combining an alkanolamine (especially triethanolamine) and stearic acid and/or sebacic acid.

In another embodiment a grease composition having a thickener may also be prepared, wherein the thickener is obtainable from: one or more mono-or polyisocyanates, preferably diisocyanates, especially tolylene diisocyanate and/or methylene diphenyl isocyanate or dimers thereof, with the general formula R'₂N-R amine and/or R'₂N-R-N-R'₂Or with an amine or a mixture of diamines, wherein R is an aryl, alkyl or alkylene group, especially a polyaryl, Polyalkyl (Polyalkyl) or polyalkylene group.

"polyisocyanates" include, in addition to integral multiples of isocyanates (preferably di-, tri-, tetra-isocyanates), in particular oligomeric or polymeric isocyanates and also half-multiples of isocyanates or mixtures thereof.

In a preferred embodiment, the thickener comprises the reaction product of one or more diisocyanates with a primary amine.

The grease composition of the present invention may especially be prepared by combining a base oil consisting of water and sodium carboxymethylcellulose and a thickener component obtainable by combining a mixture formed from one or more diisocyanates, preferably aryl diisocyanates, especially toluene diisocyanate and/or methylene diphenyl isocyanate, with an alkylamine, preferably a C1 to C10 alkylamine, especially preferably octylamine and/or alkylene diarylamine, especially methylene diphenylamine, or with a mixture of amines or diamines.

The term "alkyl" refers to a saturated hydrocarbon chain. According to the invention, the alkyl radical has in particular the formula-C_nH_2n+1。

"alkenyl" refers to a hydrocarbon chain that contains at least one double bond along the chain. For example, alkenyl radicals having a double bond are of the formula-C in particular_nH_2n-1. However, alkenyl groups may also have more than one double bond.

"aryl" refers to monocyclic (e.g., phenyl), bicyclic (e.g., indenyl, naphthyl, tetrahydronaphthyl, or tetrahydroindenyl), and tricyclic (e.g., fluorenyl, tetrahydrofluorenyl, anthracenyl, or tetrahydroanthracenyl) ring systems in which at least one of the monocyclic ring system or rings in the bicyclic or tricyclic ring system is aromatic.

The grease composition may be described by the so-called consistency characteristic (NLGI grade; national grease research institute). The grading extends from 000 up to 6. The grease composition of the present invention is preferably in the range of NLGI 000 and NGLI 4, preferably in the range between NLGI 0 and NLGI 3, particularly preferably it has a consistency characteristic of NLGI 2.

The "consistency" is here a measure of the inertial capacity of the fat (i.e. the resistance of the fat against deformation). Consistency can be determined by cone penetration testing. The "penetration" method according to DIN ISO 2137 is also preferably used according to the invention. The penetration is understood here to be the depth of penetration of the cone under its weight, which is specified after 5 seconds at 25 ℃. The penetration depends inter alia on the composition and structure of the respective grease. It can therefore be used to classify fats on a consistency scale.

In a preferred embodiment of the grease composition, the working penetration so measured is in the range between 475 and 170 tenths of a millimeter, preferably in the range between 385 and 220, particularly preferably in the range between 295 and 265.

In addition to the penetration for grading the consistency of the grease composition, flow pressure may also be used for grading the grease composition. This gives information about the mobility of the grease at different temperatures. By "flow pressure" is understood the pressure difference from atmospheric pressure required in order to force the grease strand out of the test nozzle. The flow pressure thus obtained characterizes the flow behaviour of the grease composition according to the invention. The flow pressure can be determined in accordance with DIN 51805-2.

In a preferred embodiment of the invention, the flow pressure of the lubricant composition measured at 20 ℃ is in the range between 60 and 90 mbar, in particular 75 mbar. In another preferred embodiment, the flow pressure of the lubricant composition measured at 0 ℃ is in the range between 85 and 115 mbar, in particular 100 mbar.

In another preferred embodiment, the flow pressure of the lubricant composition measured at-5 ℃ is in the range between 135 and 165 mbar, in particular 150 mbar. In a preferred embodiment, the flow pressure of the lubricant composition measured at-10 ℃ is in the range between 200 and 250 mbar, in particular 225 mbar. In a preferred embodiment, the flow pressure of the lubricant composition measured at-20 ℃ is in the range between 500 and 600 mbar, in particular 550 mbar.

In a particularly preferred embodiment of the grease composition according to the invention, the electrical conductivity is 10^-12And 10^-3In the range between S/cm, preferably 10^-9And 10^-3In the range between S/cm, particularly preferably 10^-7And 10^-5In the range between S/cm, especially 10^-5And 10^-3In the range between S/cm. The conductivity is preferably determined according to ISO 16773-1.

In a particularly preferred embodiment, the base oil used for preparing the grease composition of the present invention consists of water and the polymer components that can be used according to the present invention, especially the cellulose ethers and their salts. Very particular preference is given to the sodium salt of carboxymethylcellulose.

In another embodiment of the invention, the base oil has a proportion of water of 100% by weight, preferably at least 80% by weight, 50 and 60, particularly preferably at least 30% by weight.

In a preferred embodiment of the present invention, the base oil has a viscosity index of at least 120, preferably at least 140, particularly preferably at least 180. "viscosity index" refers to the temperature-dependent change in viscosity of a lubricant. It can be determined from kinematic viscosity according to ISO 3104.

The viscosity of the base oil at 40 ℃ is advantageously between 1 and 100,000mm²In the range of 1 to 10,000mm, preferably²In the range of 100 to 1500mm, particularly preferably²In the range of/s.

In a preferred embodiment, the base oil has a pour point of ≥ 0 ℃, preferably ≥ 5 ℃, especially ≥ 10 ℃, further preferably ≥ 20 ℃, very particularly preferably ≥ 50 ℃. For liquid products, "pour point" is the temperature at which the product just still flows when it is cooled. If the grease composition has a pour point of-10 c, for example, this means that the composition is still flowing at-10 c, just as it is, while at lower temperatures the composition sets. Pour point determination can be made according to ISO 3016.

In a particularly preferred embodiment, a composition consisting of water and a polymer component as defined according to the invention (preferably especially a cellulose ether and its salts) is used to prepare a grease composition having one or more of the following properties:

at 10^-7And 10^-3A conductivity in the range between S/cm,

consistency characteristic (NLGI grade) of 2

Working cone penetration in the range 295 and 265

-a flow pressure of 75 mbar at 20 ℃

-a flow pressure of 100 mbar at 0 ℃.

In another preferred embodiment, a base oil consisting of water and a polymer component as defined according to the present invention (preferably especially cellulose ethers and salts thereof) is used for preparing the grease composition, wherein the base oil has one or more of the following properties:

-in the range 500 to 1500mm²Viscosity in the/s range

Pour point of-0 ℃ or higher

-a viscosity index of at least 180.

A very particularly preferred polymer component for these preferred compositions is the sodium salt of carboxymethyl cellulose.

Very particular preference is given to using the base oils as defined herein for preparing the grease compositions of the present invention.

To further characterize the grease composition of the present invention, other parameters may be determined.

The following parameters can preferably be determined here:

-welding force

Characteristic value of wear

Corrosion performance with respect to copper and aluminum.

Here, "welding force" is understood to mean the test force in newtons (N) at which the test device is brought into the immovable state, in particular by welding of a four-ball system in the test apparatus.

"effective force" (Gutkraft) refers to the test force in newtons (N) measured before the weld force is reached, at which no immovable state is yet entered, particularly no welding of the four-ball system in the test apparatus occurs.

"VKA welding force" means here the test force in newtons (N) for effective force and welding force, measured according to DIN 51350-4.

The process for preparing the grease composition of the present invention preferably comprises the steps of:

(i) providing a base oil formed from a mixture consisting of water and one or more water soluble polymers;

(iia) combining the base oil with at least one thickener

(iii) Optionally, heating the mixture

(iv) Optionally, additives are added

Additives and additives may in principle be added to the grease composition of the present invention, as is known from the prior art in the field of lubricant compositions. For example, emulsifiers, stabilizers, solubilizers and so-called extreme pressure additives (EP additives) can be used in addition to the corrosion inhibitors.

In a particularly preferred embodiment, the process for preparing the grease composition of the present invention comprises the steps of:

(iia) combining the base oil with at least one thickener, wherein the at least one thickener has a drop point of at most 300 ℃, preferably at most 280 ℃, particularly preferably 260 ℃; or (iib) combining the base oil with at least one thickener, wherein the at least one thickener has a melting point of greater than 260 ℃, preferably greater than 280 ℃, particularly preferably greater than 300 ℃;

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

A preferred embodiment is a method of preparing a grease composition, the method comprising the steps of:

(i) providing a base oil formed from a mixture consisting of water and one or more water soluble polymers,

(iia) combining the base oil with at least one thickener, wherein the at least one thickener has a drop point of at most 300 ℃, preferably at most 280 ℃, particularly preferably 260 ℃;

(iib) combining the base oil with at least one thickener, wherein the at least one thickener has a melting point of greater than 260 ℃, preferably greater than 280 ℃, particularly preferably greater than 300 ℃;

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

A particularly preferred embodiment describes a method of preparing a grease composition, the method comprising the steps of:

(ii) combining the base oil with at least one thickener,

wherein the thickener is prepared in situ in the base oil by combining at least two components forming the thickener;

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

Especially preferred is a process for preparing a grease composition, said process comprising the steps of:

(ii) combining the base oil with a thickener, wherein the thickener is prepared in situ in the base oil by combining at least two components forming the thickener, preferably having one or more metal hydroxides, particularly preferably selected from the group consisting of: lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, especially potassium hydroxide,

(iii) optionally, the mixture is heated to 40 to 90 ℃, especially 60 to 80 ℃,

(iv) adding one or more mono-and/or dicarboxylic acids, preferably selected from the group consisting of: stearic acid, 12-hydroxystearic acid, sebacic acid, oleic acid or mixtures thereof,

(v) optionally, heating the mixture;

(vi) optionally, additives are added.

In another preferred embodiment, the method of preparing a grease composition comprises inter alia the steps of:

(ii) combining the base oil with a thickener, wherein the thickener is prepared in situ in the base oil by combining at least two components forming the thickener;

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

In the case of soap thickeners, one component is a metal hydroxide or an alkylamine or alkanolamine and the second component is a carboxylic acid according to the invention.

In the case of polyureas, one component is a diisocyanate and the second component is an amine according to the invention.

In the case of the in situ preparation of soap thickeners, it is advantageous to place the base (e.g. metal hydroxide) in the base oil beforehand and then to heat the mixture first. In this case, temperatures of 40 to 90 ℃ are advantageous, particularly preferably 60 to 80 ℃. The fatty acids, preferably monocarboxylic and/or dicarboxylic acids, are then added.

In the case of the in situ preparation of soap thickeners according to the invention, metal hydroxides selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, especially potassium hydroxide, are of particular interest.

In the compositions, processes and base oils of the invention and the use of the base oils of the invention, carboxymethyl cellulose, very particularly preferably the sodium salt of carboxymethyl cellulose, is particularly preferred as the polymer component.

In a particular aspect, the present invention relates to a lubricant composition comprising water and a first component formed from one or more thickeners or salts thereof (thickener component) and a second component formed from one or more natural or chemically modified polymers or salts thereof (polymer component), wherein the thickener is obtainable by combining a mono-or dicarboxylic acid or a mixture thereof with an alkanolamine, alkylamine or a mixture thereof.

The above definitions apply equally to this particular aspect of the invention, as long as it is not explicitly stated otherwise in the following.

Such grease compositions have the particular advantage that the thickener component can form an ionic complex with the polymer component which is interface-active. This can additionally have a favorable effect on the lubrication properties.

The use of amines for forming the thickener component has the advantage that the biological inhibiting effect known from amines can thus also be utilized at the same time. This enables the biocide in the composition to be reduced or even completely omitted. In addition, the amines may additionally impart a certain corrosion protection function to the composition. The use of other corrosion inhibitors can be reduced.

Amines, especially triethanolamine, also have buffering properties. The use of an amine in the thickener component may thus buffer the pH of the grease composition and thus improve the stability of the composition.

In a particularly preferred embodiment of the invention, the amine is a trialkanolamine, preferably selected from the group consisting of: triethanolamine, tripropanolamine, tributanolamine or mixtures thereof. Triethanolamine is particularly preferred.

Preferably, monocarboxylic acids are used to form the thickener component. The monocarboxylic acid is preferably selected from the group consisting of: saturated monocarboxylic acids or monounsaturated monocarboxylic acids, further preferably myristic acid, myristic acid derivatives, palmitic acid derivatives, margaric acid derivatives, stearic acid derivatives, arachidic acid derivatives, palmitoleic acid derivatives, oleic acid derivatives, elaidic acid derivatives, eicosenoic acid derivatives, cetenoic acid derivatives or mixtures thereof, particularly preferably stearic acid, stearic acid derivatives, oleic acid derivatives or mixtures thereof, in particular stearic acid, 12-hydroxystearic acid, oleic acid or mixtures thereof. Stearic acid or 12-hydroxystearic acid is particularly preferred.

In a very particularly preferred embodiment, the thickener can be obtained by combining a monocarboxylic acid, preferably stearic acid or 12-hydroxystearic acid, with an alkanolamine, in particular with a trialkanolamine. Triethanolamine is particularly preferred.

By varying the thickener concentration, the consistency characteristic (NLGI grade; national institute for lubricating grease) can be adjusted to be in the range between NLGI 000 and NGLI 4, preferably in the range between NLGI 0 and NLGI 3, particularly preferably NLGI 2.

In the case of thickeners obtainable by combining stearic acid with triethanolamine, in a particularly preferred embodiment, an NLGI grade of 2 can be adjusted by adding 30 to 35% by weight of stearic acid and 15 to 20% by weight of triethanolamine.

The polymer component is preferably selected from the group consisting of: salts of modified cellulose ethers, preferably salts of carboxymethylcellulose, especially sodium carboxymethylcellulose.

The polymer component is used primarily to modify the viscosity of the base oil. The viscosity here may be from 1 to 100,000mm at 40 DEG C²S, preferably 1 to 10,000mm²S, particularly preferably from 100 to 1500mm²/s。

In a preferred embodiment of this aspect of the invention, when the thickener component has a dropping point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃, the relative proportion of water is at most 70 wt.%, preferably at most 50 wt.%, particularly preferably at most 40 wt.%, very particularly preferably at most 35 wt.%.

In an alternative embodiment of this aspect of the invention, the maximum proportion of water is in the range from 10 to 95% by weight, preferably in the range from 20 to 70% by weight, particularly preferably in the range from 30 to 50% by weight.

The lubricant composition according to this aspect of the invention may additionally comprise one or more synthetic polymers. In this case, the relative proportion of the synthetic polymer (or synthetic polymers) in the total composition is less than 5 wt.%, in particular at most 4.5 wt.%, further preferably at most 3 wt.%, still further preferably at most 1.5 wt.%, in particular at most 0.5 wt.%.

The synthetic polymer is preferably selected from the group consisting of: polyvinyl alcohol, pyrrolidone and aliphatic polyether. Preferred are polyethylene glycol, polypropylene glycol or mixtures thereof, further preferred are polyethylene glycol, particularly preferred are polyethylene glycol having a molecular weight in the range of 600 to 10,000,000Da, especially polyethylene glycol having a molecular weight in the range of 10,000 to 1,000,000 Da.

Grease compositions comprising a salt of carboxymethylcellulose (especially sodium carboxymethylcellulose) and polyethylene glycol (especially polyethylene glycol having a molecular weight in the range of from 10,000 to 1,000,000) as polymer components and a thickener obtainable by combining stearic acid and a trialkanolamine (especially triethanolamine) are particularly preferred.

The grease composition may additionally comprise commercially available antifreeze agents. Antifreeze agents can be used to adjust the freezing point, vapor pressure, or pour point of the composition. The antifreeze agent is preferably selected from the group consisting of: polyols, salts or ionic liquids, glycerol being particularly preferred. The antifreeze agent may be included in the grease composition in relative proportions of up to 60% by weight, preferably up to 30% by weight, particularly preferably up to 15% by weight, in particular up to 10% by weight.

In one embodiment of the invention, the lubricant composition may also comprise commercially available corrosion inhibitors. The corrosion inhibitor is preferably selected from the group consisting of: triazoles, thiadiazoles, amine salts and alkali metal salts of: sulfonates, phosphonates, thiophosphonates, carboxylic acids, or mixtures thereof.

Furthermore, in another embodiment of the present invention, commercially available emulsifiers may be added to the lubricant composition. Here, the emulsifier is preferably selected from the group consisting of: an organophosphate ester, a fatty acid glycol ether, an alkyl polyglycol ether carboxylic acid, or mixtures thereof.

According to an alternative embodiment of the present invention, a particularly preferred grease composition of the present invention comprises the following components:

TABLE 1

Classes of compounds	Preference is given to	Preferred proportions^*	Particularly preferred proportions^*
				Trialkanolamine	Triethanolamine	5 to 25	10 to 20
Modified cellulose ethers	Salt of carboxymethyl cellulose	0.5% to 5.0%	1 to 3
				Monocarboxylic acids	Stearic acid	10 to 40	20 to 35

^*Expressed in weight% in each case based on the total grease composition

In an alternative embodiment, the composition may comprise the following components:

TABLE 2

Very particularly preferred compositions (formulations) result from the combination of the components of table 1 or 2 with corresponding amounts of water (addition to 100% by weight). Example 1 is given as an example for one embodiment of table 2.

In an alternative particularly preferred embodiment, the grease composition of the present invention comprises the following components:

TABLE 3

Classes of compounds	Preference is given to	Preferred proportions^*	Particularly preferred proportions^*
				Trialkanolamine	Triethanolamine	1 to 15	5 to 10
Modified cellulose ethers	Salt of carboxymethyl cellulose	0.1 to 5.0	0.5 to 2
				Monocarboxylic acids	Stearic acid	1 to 10	4 to 8

The following example 10 is illustrative of this embodiment of the invention.

Detailed Description

General preparation method

Formulating the grease composition of the present invention

Example 1 preparation of a grease composition according to the invention

Preparation of base oil

A mixture of 22.5g of sodium carboxymethylcellulose and 0.5g of polyethylene glycol (Mw about 90,000g/mol) was dissolved in 322.0g of water.

Preparation of a grease composition

17.5g of potassium hydroxide (KOH) and 174.0g of triethanolamine were dissolved in 322.0g of base oil. 328g of stearic acid are added with stirring. The reaction product was stirred at room temperature for 15 minutes. 15.0g of corrosion inhibitor, 83.5g of glycerol and 37.0g of emulsifier are added. The mixture is subsequently homogenized by rolling.

	Components	By weight%
			1	Water (W)	32.2
2	Triethanolamine (TEA)	17.4
			3	Polyethylene glycol	0.05
4	Sodium carboxymethylcellulose (CMC)	2.25
			5	KOH–45％	1.75
6	Stearic acid	32.8
			7	Corrosion inhibitors	1.5
8	Glycerol-86.5%	8.35
			9	Emulsifier	3.7

Greases were investigated according to standardized methods. The obtained grease has the following excellent properties:

for the following examples the base oil mixture of the invention consisting of a mixture of 160g of sodium carboxymethylcellulose and 9840g of water was used.

Example 2 grease composition with simple lithium Metal soap

6.7g of lithium hydroxide were dissolved in 453.2g of base oil mixture at 60 ℃. 40.1g of stearic acid are added with stirring. The reaction product was heated to 80 ℃ and held at this temperature for 15 minutes. The mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	89.2
2	Sodium carboxymethylcellulose (CMC)	1.5
			3	LiOH	1.3
4	Stearic acid	8.2

example 3 grease composition with simple calcium Metal soap

30g of calcium hydroxide (ca (oh)2 x 2H2O) were dissolved in 349g of base oil mixture at 70 ℃. 121g of 12-hydroxystearic acid are added with stirring. The mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	68.7
2	Sodium carboxymethylcellulose (CMC)	1.1
			3	Ca(OH)2*2H2O	6.00
4	12-Hydroxystearic acid	24.2

example 4 grease composition with simple barium Metal soap

83g of potassium hydroxide (KOH) were dissolved in 308g of the base oil mixture at 70 ℃. 154g of stearic acid are added with stirring. After cooling, rolling of the mixture provides a homogenized grease composition.

	Components	By weight%
			1	Water (W)	60.6
2	Sodium carboxymethylcellulose (CMC)	1.0
			3	KOH	7.00
4	Stearic acid	30.8

Greases were investigated according to standardized methods. The grease obtained had the following properties:

example 5 grease composition with simple barium Metal soap

35g of barium hydroxide (Ba (OH) 2. multidot. H2O) were dissolved in 450g of base oil mixture at 80 ℃. 99g of stearic acid are added with stirring. The reaction mixture was stirred at 80 ℃ for 15 minutes. Cooling and rolling of the mixture provides a homogenized grease composition.

	Components	By weight%
			1	Water (W)	88.6
2	Sodium carboxymethylcellulose (CMC)	1.4
			3	Ba(OH)2*H2O	7.00
4	Stearic acid	19.8

example 6 grease composition with simple sodium Metal soap

22.5g of sodium hydroxide (NaOH) were dissolved in 318.0g of base oil mixture at 70 ℃. 160g of stearic acid are added with stirring. After cooling the mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	62.6
2	Sodium carboxymethylcellulose (CMC)	1.0
			3	NaOH	4.5
4	Stearic acid	32.0

example 7 lubricating grease composition with lithium Complex soap

21g of lithium hydroxide (LiOH) were dissolved in 386.5g of base oil mixture at 60 ℃. A mixture of 62.5g of 12-hydroxystearic acid and 30g of sebacic acid is added with stirring. The mixture was heated to 90 ℃ and stirred at this temperature for 15 minutes. Cooling and rolling provide a homogenized grease composition.

	Components	By weight%
			1	Water (W)	76.1
2	Sodium carboxymethylcellulose (CMC)	1.2
			3	LiOH	4.2
4	12-Hydroxystearic acid	12.5
			5	Sebacic acid	6.00

example 8 lubricating grease composition with sodium Complex soap

19.25g of sodium hydroxide (NaOH) were dissolved in 388.0g of base oil mixture at 60 ℃. A mixture of 62.5g of 12-hydroxystearic acid and 30g of sebacic acid is added with stirring and heated at 80 ℃ for 15 minutes. Cooling and rolling provide a homogenized grease composition.

	Components	By weight%
			1	Water (W)	76.4
2	Sodium carboxymethylcellulose (CMC)	1.2
			3	NaOH	3.9
4	12-Hydroxystearic acid	12.5
			5	Sebacic acid	6.00

example 9 grease composition with barium Complex soap

41.3g of barium hydroxide (Ba (OH) 2H2O) were dissolved in 385.0g of base oil mixture at 70 ℃. A mixture of 47.1g of stearic acid and 26.6g of sebacic acid is added with stirring. After cooling the mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	75.8
2	Sodium carboxymethylcellulose (CMC)	1.2
			3	Ba(OH)2*H2O	8.3
4	Stearic acid	9.4
			5	Sebacic acid	5.3

preparation of Lubricants with Triethanolamine soaps

Example 10

17.4g triethanolamine were placed beforehand in a 220.0g base oil mixture at 25 ℃ with stirring. 32.8g of stearic acid are added with vigorous stirring. The mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	80.1
2	Sodium carboxymethylcellulose (CMC)	1.3
			3	Triethanolamine	6.4
4	Stearic acid	12.2

preparation of gel fat example 11

10.0g of highly disperse silica (HDK T40) were placed beforehand in a mixture of 90.0g of base oil at 25 ℃ with stirring. The mixture was homogenized by rolling.

	Components	By weight%
			1	Water (W)	88.6
2	Sodium carboxymethylcellulose (CMC)	1.4
			3	HDK T40	10.0

the general implementation of the test method:

1. determination of the penetration according to DIN ISO 2137

The penetration of the grease was measured at 25 ℃ by loosening the cone assembly from the penetrometer and allowing the cone to sink for 5 seconds. The depth of penetration was then measured.

As cone used, an optional cone according to DIN ISO 2137 is used, which consists of a brass truncated cone with a screwable hardened steel tip. Optionally a quarter cone according to DIN ISO 2137 may be used.

The dimensions and the limit deviations correspond to fig. 3 and fig. 5 of DIN ISO 2137.

A) Execution of static cone penetration

The static cone penetration was determined for a sample set packed into a container suitable for testing under low mechanical stress.

Preparing the sample

Sampling was performed according to ASTM D4057. The samples can be examined for inhomogeneities, oil deposits, phase transitions or coarse impurities. The new samples were used under differential conditions. A sufficient amount of sample was taken to overfill the pan of the grease kneader.

An empty metal container and another metal container filled with the sample were used in a water bath according to DIN ISO 2137. Here, the temperature of the sample was brought to 25 ℃ and maintained at this temperature. The samples were transferred into the metal containers of a grease kneader, care being taken to work as little as possible with the samples. The container is opened to allow the escape of air that may be entrained. The grease was then compacted with a spatula under a small stress. Excess grease was removed by pulling the edge of the scraper over the pan rim at an angle of about 45 ° to the direction of movement and creating a flat surface.

There was no further process of smoothing or smoothing the surface during the determination of the static cone penetration, immediately followed by the measurement.

The cone of the penetrometer was carefully cleaned before each test and reliably held in the raised position during cleaning. Possible grease or oil residues are completely removed from the rod of the penetrometer.

Cone penetration measurement

The pan is placed on the cone penetration table oriented exactly horizontally and the mechanism is adjusted so that the cone remains in the "zero" position. Care is taken at each measurement to orient the apparatus carefully so that the tip of the cone touches the surface of the sample at exactly the point determined depending on the consistency of the respective sample. The observation is made by means of the shadow of the tip of the cone. The pan is centered by means of a centering device, depending on the properties of the grease. The awl bar is quickly loosened, then allowed to fall for 5.0 seconds, and then secured in this position. At this point the display rod is carefully depressed until it is held by the awl rod. The cone penetration can then be read from the display scale.

In the case of samples with a cone penetration of more than 200 units, these samples were used for one test only. With a cone penetration of 200 units or less, three tests were carried out in a single container by starting the cone penetration at angular intervals of about 120 ° each, to be precise approximately halfway between the midpoint of the container and the wall.

A total of three determinations were made with one grease sample.

B) Execution of working cone penetration

The working cone penetration was determined immediately after the samples were worked in a standard grease kneader with 60 double strokes.

Work by

A sufficient amount of sample was taken to overfill the pan of the grease kneader.

The assembled grease kneader was placed in a water bath maintained at 25 ℃ until the temperature of the grease kneader and its contents was 20.0 ℃. The grease was then subjected to 60 double strokes with the piston in 1 minute. The following further experiments were carried out one after the other in a short time.

Preparing the sample

For further testing according to DIN ISO 2137, the worked samples were prepared in a pan.

Cone penetration measurement

The cone penetration was determined as already described under A).

2. Determination of NLGI grade

The national grease institute (NLGI) grades greases according to grease consistency determined with 60 strokes of working penetration. The NLGI grade contains nine consistency grades or grades, each of which corresponds to a determined working cone penetration range. NLGI ratings are defined in ISO 6743-99 and are detailed in the following table for a rating of 000 to 4:

3. determination of the dropping Point of the grease composition

The determination of the dropping point corresponds to the requirements of standard IP 396, carried out fully automatically by means of a double heating ramp. The grease to be measured is brought to an initial temperature of 10 ℃ above ambient temperature. The sample was then heated at a heating rate of 10 ℃/minute to a starting temperature that was dependent on the expected sample drop point. Once a temperature of 20 ℃ below the expected drop point is reached, the heating rate is reduced to 1 ℃/minute.

In the first measurement of the unknown dropping point, the dropping point should first be roughly measured. For this purpose, a heating rate of 10 ℃/min is adjusted over the entire measuring period. This approximately determined drop point value can be used to determine a temperature 20 ℃ below the expected drop point. The second measurement provides the drop point of the grease composition.

4. Determination of the flow pressure of greases according to the method of Kesternich in accordance with DIN51805-2

The grease-filled test nozzle of the test device is connected to the device for generating gas pressure and to the pressure measuring device. At a defined test temperature (which can be adapted to the respective grease), the pressure is increased, preferably at intervals of 30 seconds, by a certain value (which depends on the flow pressure of the grease) for a certain time until the grease strand is discharged from the test nozzle and the pressurized gas escapes through the test nozzle.

Temperature control of a test device

The tempering room equipped with the test nozzle is tempered preferably for 2 hours before the test starts. The sample to be measured is measured at 20 ℃,0 ℃, -10 ℃ and-20 ℃. The proposed maximum time span set forth in DIN51805-2 is preferably maintained until the proposed test temperature is reached.

5. Determination of wear scar according to DIN 51350-5

The grease compositions were tested in a four-ball system (DIN 51350-1), which preferably consists of one rotating ball (running ball) which is guided under a fixed test force onto three balls identical thereto (static balls). The test time may preferably be 60 minutes or 60 seconds. The wear scar diameters of the three static balls were then measured and averaged.

Execute

The ball pan or ball holder consisting of the fixture, press plate and test ball is carefully cleaned and dried in a residue-free solvent (preferably FAM gasoline).

The cleaned ball pan was filled in a bubble-free manner with the grease composition to be tested. Three cleaned test balls (DIN 51350-1), preferably static balls, are then gently pressed in and firmly clamped. The ball pan is filled such that the stationary balls are covered and the ball holder is not immersed in the grease. Excess grease composition is preferably removed on the ball pan rim by means of a spatula. The ball pan and the grease composition in particular have a temperature between 18 ℃ and 40 ℃. Another test ball is pressed into the ball holder as a running ball and inserted into the test spindle. After the insertion of the ball pan with its mandrel tip onto the depression of the rotary table, a test force is applied, wherein the test force is preferably adjusted to 150N, 300N or 1000N according to three different methods. In addition, the drive motor was adjusted to 1450 revolutions per minute.

Evaluation of

To determine the average wear scar diameter, the wear scar diameter on the stationary ball was measured in the sliding direction and perpendicular to the sliding direction. An arithmetic mean is formed from the individual values thus obtained.

6. Determination of the weld force according to DIN51350-4

The grease compositions according to the invention were tested in a four-ball system (DIN 51350-1), which preferably consisted of one rotating ball (running ball) which was guided under a fixed test force onto three balls identical thereto (stationary balls) (analogously to point 5). The test force may be increased in steps until a four ball system weld condition is reached. The test was performed analogously to the execution in point 5 (see above).

However, in order to measure the bonding force, the test force is increased for a certain time until the bonding state of the ball is entered. For this purpose, the test force is increased by 200N in the test force range between 2000N and 4800N or by 500N in the test force range between 5000N and 12000N, respectively, as the test progresses.

Evaluation of

The VKA welding force of the grease composition is preferably determined by two identical individual measured values of in each case three experiments for the effective force and the welding force.

7. Determination of the Corrosion behaviour on copper in accordance with DIN 51811

To test the corrosion performance of the grease, rolling bearings, sliding bearings and sliding surfaces were investigated in the presence of water under conditions close to the operating state. The mechanically polished copper or aluminum bars were left in the grease samples for 24 hours. The degree of corrosion was then evaluated on the basis of staining. The test temperature depends on the upper temperature limit of the use of the respective grease and may be 50 ℃, 100 ℃ and/or other specified temperatures.

Preparing copper/aluminum strips

All surface defects were removed by means of a sanding paper or cloth. Optionally, the polishing medium can additionally be placed on a flat surface, wetted with a certain solvent and rubbed against the copper strip thereon in a circular motion. The copper bars were stored under solvent until use. The copper bar is inserted into the fixture with the aid of forceps.

Execute

Directly after the preparation of the copper or aluminum strip, it is dipped obliquely at room temperature into a beaker which has been filled beforehand at room temperature with the grease to be tested to 10mm below the rim of the cup and is preferably bubble-free. The copper bars here preferably protrude 10mm from the grease. The test is performed according to a specified test duration and/or temperature.

8. Determination of the conductivity of the grease composition

To test the conductivity, the grease composition was measured by means of the impedance spectroscopy method according to ISO 16773-1. Impedance spectroscopy is a method used to study ion transport processes in solids. For the grease composition to be investigated, an alternating voltage (preferably of low amplitude) is applied by introducing the sample into an electrochemical cell. The alternating voltage may generate an alternating current in the sample having the same frequency, which is measured by means of a frequency response analyzer. Corresponding control and evaluation software can generate an equivalent circuit diagram depending on the respective sample by means of the system data and compare it with the measured frequency transformation and thus obtain the conductivity of the sample.

Sample preparation and execution

The grease composition is filtered before the respective measurement, preferably an inert filter material, in particular ceramic, is used here, and the sample is degassed, preferably the degassing of the sample can be carried out in an ultrasonic bath at elevated temperature. The corresponding sample can then be filled into the test cell. Preferably the sample is heated stepwise in the range between 0 and 150 ℃. The sample is then preferably cooled within the same range between 150 and 0 ℃. The conductivity was obtained with the aid of evaluation software.

9. Determination of the pour Point of the grease composition (according to DIN ISO 3016)

The sample container was filled with the sample at room temperature until the ring mark. The sample container was closed with a stopper containing a pour point thermometer. The plug and thermometer were oriented so that the plug was firmly in place, the thermometer and sample container extended coaxially and the thermometer container was submerged so that the start of the capillary was about 3mm below the oil surface. The sample vessel was placed in an ethanol bath without a jacketed vessel. In case of oils with pour points below-15 ℃ as expected, the samples were cooled down to 0 ℃ in large steps. The sample was then further cooled in 3 ℃ steps. In these intervals it is detected whether the oil is still able to flow. The temperature was tested until no further sample movement was observed after 5 seconds in the horizontal position.

10. Determination of the viscosity index of the grease composition

For the determination of the viscosity index, the kinematic viscosity is obtained according to the corresponding implementation in DIN 51562-1. Kinematic viscosity was measured at 40 ℃ and 25 ℃. The viscosity index is calculated according to the corresponding evaluation software, taking into account the kinematic viscosity at 40 and 25 ℃.

Detailed description of the preferred embodimentsEmbodiment 1

A lubricant composition comprising water and a first component formed from one or more thickeners or salts thereof (thickener component), wherein

a) When the thickener component has a dropping point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃, the relative proportion of water is at most 70% by weight, preferably at most 50% by weight, particularly preferably at most 40% by weight, very particularly preferably at most 35% by weight;

or

b) When the thickener component has a melting point of more than 260 ℃, preferably more than 280 ℃, particularly preferably more than 300 ℃, the relative proportion of water is at most 40 wt.%, preferably at most 35 wt.%.

Embodiment 2:

the lubricant composition of embodiment 1, wherein

a) When the thickener component has a dropping point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃, the relative proportion of water is at least 10 wt.%, preferably at least 15 wt.%, particularly preferably at least 20 wt.%, very particularly preferably at least 30 wt.%;

or

b) When the thickener component has a melting point of more than 260 ℃, preferably more than 280 ℃, particularly preferably more than 300 ℃, the relative proportion of water is at least 20 wt.%, preferably at least 25 wt.%, particularly preferably at least 30 wt.%.

Embodiment 3:

a lubricant composition according to one of embodiments 1 or 2 comprising water and a first component formed from one or more thickeners or salts thereof (thickener component), wherein the lubricant composition comprises a second component formed from one or more water soluble polymers or salts thereof (polymer component).

Embodiment 4:

the lubricant composition according to embodiment 3, wherein the relative proportion of the polymer components in the total composition is from 0.05 to 15, preferably from 0.1 to 10, especially from 0.1 to 5 wt.%.

Embodiment 5:

the lubricant composition according to one of the preceding embodiments 3 or 4, wherein the weight ratio of the polymer component to the thickener component is between 1:60 and 1:2, preferably between 1:40 and 1:3, in particular between 1:30 and 1: 5.

Embodiment 6:

the lubricant composition according to one of the preceding embodiments, wherein the relative proportion of the thickener component in the total composition is at least 20 wt.%, preferably at least 30 wt.%, further preferably at least 35 wt.%, very preferably more than 35 wt.%.

Embodiment 7:

the lubricant composition according to one of the preceding embodiments 3 to 6, wherein with respect to the total composition

The relative proportion of water is between 25 and 95% by weight,

the relative proportion of the polymer components is between 0.5 and 4.0% by weight, and

the relative proportion of the thickener component is between 5 and 70% by weight.

Embodiment 8

The lubricant composition according to one of the preceding embodiments 3 to 7, wherein the polymer of the polymer component is selected from the group consisting of:

b) chemically modified polymers such as cellulose ethers, cellulose esters and modified starches;

c) synthetic polymers such as polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone;

or mixtures thereof.

Embodiment 9:

the lubricant composition according to one of the preceding embodiments 3 to 8, wherein the natural polymer of the polymer component is selected from the group consisting of:

alginates, pectins, cellulose, gelatin, and natural starches.

Embodiment 10:

the lubricant composition according to one of the preceding embodiments 3 to 9, wherein the semi-synthetic polymer of the polymer component is selected from the group consisting of:

cellulose ethers and/or esters, in particular ethylcellulose, propylcellulose, carboxymethylcellulose (CMC), Hydroxypropylcellulose (HPC), Hydroxypropylmethylcellulose (HPMC) and cellulose acetate, especially preferably carboxymethylcellulose (CMC) or salts thereof, preferably sodium salts, or mixtures thereof.

Embodiment 11:

the lubricant composition according to one of the preceding embodiments, wherein the thickener component is selected from the group consisting of: soap thickeners, especially simple metallic soaps, complex soaps and/or mixed metallic soaps, non-soap thickeners, especially urea, clays, especially bentonite, montmorillonite or bauxite, silicates, silicic acid, talc, polytetrafluoroethylene, metal salts, pigments, graphite, or mixtures thereof.

Embodiment 12:

the lubricant composition of embodiment 11, wherein the soap thickener comprises a cation, wherein the cation is selected from the group consisting of, inter alia: metals of main groups 1, 2, 3, 4 and metals of sub-group 12, preferably selected from the group consisting of: li, Na, K, Ca, Ba, Al and/or Zn, particularly preferably selected from the group consisting of: li, Na, K and Ca.

Embodiment 13:

the lubricant composition of one of the previous embodiments 11 or 12, wherein the anion of the soap thickener is selected from the group consisting of: saturated C2 to C30 mono-or dicarboxylic acids, mono-or polyunsaturated C2 to C30 mono-or dicarboxylic acids, aromatic C5 to C30 mono-and dicarboxylic acids or mixtures of such carboxylic acids, preferably selected from the group consisting of: saturated C2 to C20 mono-or dicarboxylic acids, mono-or polyunsaturated C2 to C20 mono-or dicarboxylic acids, aromatic C5 to C30 mono-and dicarboxylic acids or mixtures thereof, particularly preferably selected from the group consisting of: stearic acid, sebacic acid, 12-hydroxystearic acid, adipic acid and azelaic acid, terephthalic acid, or mixtures thereof.

Embodiment 14:

the lubricant composition of embodiment 11, wherein the thickener is obtainable from: one or more mono-or polyisocyanates, preferably diisocyanates, especially tolylene diisocyanate and/or methylene diphenyl isocyanate or dimers thereof, with the formula R'₂N-R amine and/or general formula R'₂N-R-N-R'₂Or with an amine or a mixture of diamines, wherein R is an aryl, alkyl or alkylene group, especially a polyaryl, polyalkyl or polyalkylene group, preferably a primary amine.

Embodiment 15:

lubricant composition according to one of the preceding embodiments 11 to 14, wherein the thickener component is obtainable by combining water, a thickener component according to claim 11, in particular a soap thickener as defined according to claim 12 or 13, and an alkanolamine and/or an alkylamine, preferably an alkanolamine, in particular preferably triethanolamine.

Embodiment 16:

the lubricant composition according to one of the preceding embodiments, wherein the consistency characteristic value (NLGI grade) is in the range between 000 and 4, in particular 2.

Embodiment 17:

lubricant composition according to one of the preceding embodiments, wherein the working cone penetration is in the range between 475 and 170 tenths of a millimeter, preferably in the range between 385 and 220, particularly preferably in the range between 295 and 265.

Embodiment 18:

the lubricant composition according to one of the preceding embodiments, wherein the electrical conductivity is at 10^-12And 10^-3In the range between S/cm, particularly preferably 10^-9And 10^-3In the range between S/cm, very particularly preferably in the range of 10^-7And 10^-3In the range between S/cm, especially 10^-5And 10^-3In the range between S/cm.

Embodiment 19:

a base oil for use in preparing a lubricant composition, wherein the base oil comprises, preferably consists of, water and a polymer component as defined in any one of embodiments 3 to 5 and 7 to 10.

Embodiment 20:

the base oil according to embodiment 19, wherein the base oil has a proportion of water of 100 wt.%, preferably at least 80 wt.%, particularly preferably at least 30 wt.%.

Embodiment 21:

the base oil according to one of embodiments 19 or 20, wherein the base oil has a viscosity index of at least 120, preferably at least 140, particularly preferably at least 180.

Embodiment 22:

the base oil according to one of embodiments 19 to 21, wherein the base oil has a viscosity at 40 ℃ of between 1 and 100,000mm²In the range between 1 and 10,000mm, preferably²In the range between 1 and 1500mm, particularly preferably²A viscosity in the range between/s.

Embodiment 23:

the base oil according to one of embodiments 19 to 22 has a pour point of not less than 0 ℃, preferably not less than-5 ℃, especially not less than-10 ℃, further preferably not less than-20 ℃, very particularly preferably not less than-50 ℃.

Embodiment 24:

a lubricant composition comprising the base oil of one of embodiments 19-23.

Embodiment 25:

use of a composition formed from water and a polymer component as defined in one of embodiments 3 to 18 or a base oil as defined in one of embodiments 19 to 23 for the preparation of a lubricant composition.

Embodiment 26:

a method of making a lubricant composition comprising the steps of:

(iia) combining the base oil with at least one thickener

(iii) Optionally, heating the mixture

(iv) Optionally, additives are added.

Embodiment 27:

the method of preparing a grease composition according to embodiment 26, comprising the steps of:

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

Embodiment 28:

the method of preparing a grease composition according to embodiment 26 or 27, comprising the steps of:

(ii) combining the base oil with at least two reactive thickener precursors, wherein the thickener can optionally be prepared in situ by combining the at least two reactive thickener precursors;

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.

Embodiment 29:

a method of preparing a grease composition according to one of embodiments 26-28, comprising the steps of:

(ii) combining the base oil with a reactive thickener precursor, preferably with one or more metal hydroxides, particularly preferably selected from the group consisting of: lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide, especially potassium hydroxide,

(iv) optionally, additives are added.

Claims

1. A lubricant composition comprising water and a first component formed from one or more thickeners or salts thereof (thickener component) and a second component formed from one or more natural or chemically modified polymers or salts thereof (polymer component), characterized in that the thickener is obtainable by combining a monocarboxylic or dicarboxylic acid or a mixture thereof with an alkanolamine, alkylamine or a mixture thereof.

2. Lubricant composition according to claim 1, characterized in that the relative proportion of water is at most 70 wt. -%, preferably at most 50 wt. -%, particularly preferably at most 40 wt. -%, very particularly preferably at most 35 wt. -%, when the thickener component has a drop point of at most 260 ℃, preferably at most 280 ℃, particularly preferably at most 300 ℃.

3. Lubricant composition according to claim 1 or 2, characterized in that the relative proportion of the polymer components in the total composition is from 0.05 to 15% by weight, preferably from 0.1 to 10% by weight, in particular from 0.1 to 5% by weight.

4. Lubricant composition according to one of the preceding claims, characterized in that the relative proportion of the thickener components in the total composition is at least 20 wt. -%, preferably at least 30 wt. -%, further preferably at least 35 wt. -%, very preferably more than 35 wt. -%.

5. Lubricant composition according to one of the preceding claims, characterized in that the weight ratio of the polymer component to the thickener component is between 1:60 and 1:2, preferably between 1:40 and 1:3, in particular between 1:30 and 1: 5.

6. Lubricant composition according to claim 1, characterized in that the maximum proportion of water is in the range of 10 to 95% by weight, preferably in the range of 20 to 70% by weight, particularly preferably in the range of 30 to 50% by weight.

7. Lubricant composition according to claim 1, characterized in that in the total composition

The relative proportion of water is between 25 and 95% by weight,

the relative proportion of the polymer components is between 0.5 and 4.0 wt.%, and

the relative proportion of the thickener component is between 5 and 70 wt.%.

8. Lubricant composition according to one of the preceding claims, characterized in that the polymer component is selected from the group consisting of:

or mixtures thereof.

9. Lubricant composition according to one of the preceding claims, characterized in that the lubricant composition additionally comprises one or more synthetic polymers.

10. Composition according to claim 9, characterized in that the relative proportion of the synthetic polymer in the total composition is less than 5 wt. -%, at most 4.5 wt. -%, at most 3 wt. -%, further preferred at most 1.5 wt. -%, especially at most 0.5 wt. -%.

11. Composition according to one of the preceding claims 9 or 10, characterized in that the synthetic polymer is selected from the group consisting of: aliphatic polyethers, preferably polyethylene glycol, polypropylene glycol or mixtures thereof, further preferably polyethylene glycol, particularly preferably polyethylene glycol having a molecular weight in the range of approximately 600 to 10,000,000, especially polyethylene glycol having a molecular weight in the range of approximately 10,000 to 1,000,000.

12. Lubricant composition according to one of the preceding claims, characterized in that the chemically modified polymer of the polymer component is selected from the group consisting of: cellulose ethers, cellulose esters or mixtures thereof.

13. Lubricant composition according to one of the preceding claims, characterized in that the thickener comprises cations, wherein the cations are selected from the group consisting of: metals of main groups 1, 2, 3 and 4 and metals of sub-group 12.

14. Lubricant composition according to one of the preceding claims, characterized in that the anion of the thickener is selected from the group consisting of: saturated C2 to C30 monocarboxylic or dicarboxylic acids, mono-or polyunsaturated C2 to C30 monocarboxylic or dicarboxylic acids, aromatic C5 to C30 monocarboxylic and dicarboxylic acids or mixtures of such carboxylic acids.

15. The lubricant composition of claim 14, wherein the C2 to C30 monocarboxylic acid is selected from the group consisting of: saturated monocarboxylic acids or monounsaturated monocarboxylic acids.

16. The lubricant composition of claim 14 or 15, wherein the C2 to C30 monocarboxylic acid is selected from the group consisting of: myristic acid, myristic acid derivatives, palmitic acid derivatives, margaric acid derivatives, stearic acid derivatives, arachidic acid derivatives, palmitoleic acid derivatives, oleic acid derivatives, elaidic acid derivatives, eicosenoic acid derivatives, cetenoic acid derivatives, or mixtures thereof.

17. Lubricant composition according to claim 15 or 16, characterized in that in the total composition

The relative proportion of the trialkanolamines is 5 to 25 wt.%, preferably 10 to 20 wt.%,

the relative proportion of the modified cellulose ether is from 0.5 to 5% by weight, preferably from 1 to 3% by weight,

the relative proportion of the monocarboxylic acids is from 10 to 40% by weight, preferably from 20 to 35% by weight.

18. Lubricant composition according to claim 15 or 16, characterized in that in the total composition

The relative proportion of the trialkanolamines is from 1 to 15% by weight, preferably from 5 to 10% by weight,

the relative proportion of the modified cellulose ether is from 0.1 to 5% by weight, preferably from 0.5 to 2% by weight,

the relative proportion of the monocarboxylic acids is from 1 to 10% by weight, preferably from 4 to 8% by weight.

19. Lubricant composition according to one of the preceding claims, characterized in that it comprises an anti-freeze agent, preferably selected from the group consisting of: polyols, salts and ionic liquids.

20. The lubricant composition of claim 19, wherein the polyol is glycerol.

21. Lubricant composition according to one of the preceding claims 19 or 20, characterized in that the antifreeze agent is present in the lubricant composition in a relative proportion of at most 60 wt.%, preferably at most 30 wt.%, particularly preferably at most 15 wt.%, in particular at most 10 wt.%.

22. Lubricant composition according to one of the preceding claims, characterized in that it comprises a corrosion inhibitor, preferably selected from the group consisting of: triazoles, thiadiazoles, amine salts and alkali metal salts of: sulfonates, phosphonates, thiophosphonates, carboxylic acids, or mixtures thereof.

23. Lubricant composition according to one of the preceding claims, characterized in that it comprises an emulsifier, preferably selected from the group consisting of: an organophosphate ester, a fatty acid glycol ether, an alkyl polyglycol ether carboxylic acid, or mixtures thereof.

24. Lubricant composition according to one of the preceding claims 19 to 23, characterized in that in the total composition

the relative proportion of the monocarboxylic acids is from 10 to 40% by weight, preferably from 20 to 35% by weight,

the relative proportion of the polyethylene glycol is less than 5% by weight, preferably 0.01 to 0.1% by weight,

the relative proportion of the metal hydroxide is 0.5 to 5.0% by weight, preferably 1 to 3% by weight,

the relative proportion of the corrosion inhibitor is 0.5 to 5 wt%, preferably 1 to 3 wt%,

the relative proportion of the antifreeze is from 3 to 20% by weight, preferably from 5 to 15% by weight,

the relative proportion of the emulsifier is 1 to 5% by weight, preferably 2 to 4% by weight.

25. A lubricant composition comprising water and a first component formed from one or more thickeners or salts thereof (thickener component) and a second component formed from one or more natural or chemically modified polymers or salts thereof (polymer component), characterised in that the thickener is one or more diisocyanates with a formula of R'₂N-R amine and/or R'₂N-R-N-R'₂Or with an amine or a mixture of diamines, wherein R is aryl, alkylOr an alkylene group, especially a polyaryl, polyalkyl or polyalkylene group.

26. Lubricant composition according to one of the preceding claims, characterized in that the electrical conductivity is 10^-12And 10^-3In the range between S/cm.

27. A base oil for use in the preparation of a lubricant composition, characterized in that the base oil comprises, preferably consists of, water and a polymer component as defined in one of claims 1 to 26.

28. Use of a composition as defined in one of claims 1 to 26 or a base oil as defined in claim 27 for the preparation of a lubricant composition.

29. A method of making a lubricant composition comprising the steps of:

(iia) combining the base oil with at least one thickener

(iii) Optionally, heating the mixture

(iv) Optionally, additives are added.

30. A method of preparing a grease composition according to claim 30, comprising the steps of:

(iii) optionally, heating the mixture;

(iv) optionally, additives are added.