DE102020112993A1 - Lithium complex hybrid grease - Google Patents

Abstract

The present invention relates to the provision of a new lithium complex hybrid grease on the basis of a lithium complex grease in combination with a PFPE grease, which can be used at high temperature, is not laked and has a low tendency to harden. The invention also relates to the use of the new lithium complex hybrid greases in components in the vehicle sector and in the industrial sector.

Description

The present invention relates to the provision of a new lithium complex hybrid grease on the basis of a lithium complex grease in combination with a PFPE grease, which can be used at high temperature, is not laked and has a low tendency to harden. The invention also relates to the use of the new lithium complex hybrid greases in components in the vehicle sector.

Hybrid fats are mixtures that consist of at least two base oils that cannot be mixed with one another. Hybrid fats, which contain urea or urea / PTFE mixtures as thickeners and ester / PFPE as immiscible base oil components, represent an important group of these fats fluorine-free fats can be reached up to 270 ° C, which is possible with pure PTPE / PFPE fats. These products can also be adapted to specific requirements more easily than is possible with pure PFPE / PTFE greases. Only very few soluble additives are known for PFPE oils, so that, for example, the corrosion protection properties of PFPE oils can only be improved to a limited extent. In the case of PFPE / PTFE greases, solid substances such as sodium nitrite or magnesium oxide are therefore used as corrosion protection. The even distribution of a solid on the surface of a component is much more difficult to guarantee than the wetting of the surface of a component with an oil that contains a dissolved corrosion protection additive. Therefore, the additives contained in the non-fluorine-containing liquid phase of a hybrid grease can achieve properties such as corrosion protection better than is possible with a pure PFPE / PTFE grease. The reduction in the content of PFPE oils in the hybrid fat and the lower density of the hybrid fat also result in significant cost advantages. The ester / PFPE / PTFE / urea greases, for example in the EP0902828 B1 are described or the ester / PTFE / urea fats, as for example in the U.S. 6,063,743 have the disadvantage that these greases tend to post-harden at high temperatures and have very little oil separation. In addition, they can sometimes be critical when used with certain elastomers, so that they cannot be used in a wide range, such as roller bearings, in corrugated cardboard plants. In addition, the fluorinated fats are very expensive, so that there is also a need for hybrid fats that can be produced inexpensively with the same or even better properties than the fluorinated fats.

Lithium complex greases have a higher oil separation and a lower tendency to harden at high temperatures compared to ester / urea greases. However, the upper service temperature is significantly lower than with urea hybrid greases, which is often associated with excessive oil separation or is due to the use of base oils such as poly-alpha-olefins or mineral oils, which are less thermally stable.

One object of the present invention was therefore to provide a lithium complex hybrid grease with which the above-mentioned disadvantages are overcome and which has a correspondingly sufficient oil separation and low hardening even at high temperatures.

Surprisingly, this object could be achieved by combining lithium complex greases containing polyisobutylene and esters with PFPE oils or PFPE greases, in particular PFPE / PTFE greases, and thus a high-temperature performance can be achieved that is similar to the ester / urea / PFPE- Hybrid fats comes close, but does not have their disadvantages. Surprisingly, by selecting the proportions of the two fats, the oil separation can be adjusted so that the oil separation is lower than that of the two fats used for mixing.

Furthermore, a method for lubricating or greasing components, in particular in roller bearings, slide bearings, transport and control chains in vehicle technology, is provided that includes the application of the lubricant composition according to the invention.

In addition, a method for lubricating or greasing roller bearings in continuous casting plants, transport roller bearings in continuous ovens, open toothed rings in rotary kilns, tube mills, drums and mixers, bearings in corrugated cardboard plants or film stretching plants, bearings for plants for the production and transport of food is provided that the Comprising applying the lubricant composition of the invention.

1. (A) einen Ester oder Mischung von Estern, die insbesondere ausgewählt werden aus der Gruppe bestehend aus Trimellithsäureestern, Pyromellithsäureestern, Dimersäureestern, Estoliden,
2. (B) Polyisobutylenen,
3. (C) Lithiumkomplexseifen und
4. (D) PFPE-Öle.

The lubricant composition according to the invention comprises

1. (A) an ester or mixture of esters, which are selected in particular from the group consisting of trimellitic acid esters, pyromellitic acid esters, dimer acid esters, estolides,
2. (B) polyisobutylenes,
3. (C) lithium complex soaps and
4. (D) PFPE oils.

1. (A) einen Ester oder Mischung von Estern, die insbesondere ausgewählt werden aus der Gruppe bestehend aus Trimellithsäureestern, Pyromellithsäureestern, Dimersäureestern, Estoliden,
2. (B) Polyisobutylenen,
3. (C) Lithiumkomplexseifen,
4. (D) PFPE-Öle und
5. (E) ein weiteres Verdickungsmittel.

A preferred lubricant composition according to the invention comprises

1. (A) an ester or mixture of esters, which are selected in particular from the group consisting of trimellitic acid esters, pyromellitic acid esters, dimer acid esters, estolides,
2. (B) polyisobutylenes,
3. (C) lithium complex soaps,
4. (D) PFPE oils and
5. (E) another thickener.

1. (A) einen Ester oder Mischung von Estern, die insbesondere ausgewählt werden aus der Gruppe bestehend aus Trimellithsäureestern, Pyromellithsäureestern, Dimersäureestern, Estoliden,
2. (B) Polyisobutylenen,
3. (C) Lithiumkomplexseifen,
4. (D) PFPE-Öle und
5. (E) PTFE als weiteres Verdickungsmittel.

A particularly preferred lubricant composition according to the invention comprises

1. (A) an ester or mixture of esters, which are selected in particular from the group consisting of trimellitic acid esters, pyromellitic acid esters, dimer acid esters, estolides,
2. (B) polyisobutylenes,
3. (C) lithium complex soaps,
4. (D) PFPE oils and
5. (E) PTFE as a further thickening agent.

• (A) einen Ester oder Mischung von Estern, die insbesondere ausgewählt werden aus der Gruppe bestehend aus Trimellithsäureestern, Pyromellithsäureestern, Dimersäureestern, Estoliden,
• (B) Polyisobutylenen,
• (C) Lithiumkomplexseifen,
• (D) PFPE-Öle und
• (F) ein weiteres Grundöl, wobei akylierte Diphenylether bevorzugt sind.

A particularly preferred lubricant composition according to the invention comprises

• (A) an ester or mixture of esters, which are selected in particular from the group consisting of trimellitic acid esters, pyromellitic acid esters, dimer acid esters, estolides,
• (B) polyisobutylenes,
• (C) lithium complex soaps,
• (D) PFPE oils and
• (F) Another base oil, with alkylated diphenyl ethers being preferred.

1. (A) einen Ester oder Mischung von Estern, die insbesondere ausgewählt werden aus der Gruppe bestehend aus Trimellithsäureestern, Pyromellithsäureestern, Dimersäureestern, Estoliden,
2. (B) Polyisobutylenen,
3. (C) Lithiumkomplexseifen,
4. (D) PFPE-Öle,
5. (E) ein weiteres Verdickungsmittel und
6. (F) alkylierte Diphenylether.

Another preferred lubricant composition according to the invention comprises

1. (A) an ester or mixture of esters, which are selected in particular from the group consisting of trimellitic acid esters, pyromellitic acid esters, dimer acid esters, estolides,
2. (B) polyisobutylenes,
3. (C) lithium complex soaps,
4. (D) PFPE oils,
5. (E) another thickener and
6. (F) alkylated diphenyl ethers.

The lubricants according to the invention can contain additives and (H) solid lubricants as further components (G).

Component (A)

Component (A) is contained in the lubricant composition according to the invention in an amount of 70 to 7% by weight, preferably 60 to 15% by weight.

Component (A) is an ester or a mixture of esters, the ester being selected from the group consisting of trimellitic acid esters which, as alkoxy groups, have linear or branched alkyl groups containing 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms, the Alkoxy groups can be identical or different, pyromellitic acid esters, preferably tetrakis (2-ethylhexyl) pyromellitate, hydrogenated or unhydrogenated dimer acid esters, preferably bis (2-ethylhexyl) dimerate, estolides.

Estolides are understood as meaning esters which contain oligomeric units built up from homopolymers of hydroxycarboxylic acids, for example 12-hydroxystearic acid, or unsaturated carboxylic acids, for example such as oleic acid. Suitable estolides are, for example, in U.S. 6,018,063 , U.S. 6,316,649 , WO 2018/177588 A1 and the US 2013/0261325 A1 described.

Component (B)

Component (B) is a polyisobutylene or polybutene and is present in the composition according to the invention in an amount of 0.5 to 20% by weight; 1.5 to 15% by weight are preferably used.

Component (B) is a polymer, for example as in Synthetics, Mineral Oils And Bio Based Lubricants Chemistry And Technology, Second Edition, Editor Leslie R. Rudnik, Authors M. Casserino, J. Corthouts, CRC Press 2013, Pages 273 - 300 , (ISBN 978-1-4398-5537-9).

The properties of the fat according to the invention, for example its kinematic viscosity, can be influenced in the desired manner by a suitable choice of polyisobutylene, in particular with regard to the degree of hydrogenation and molecular weight. The polyisobutylene can be used in non-hydrogenated, hydrogenated or fully hydrogenated form, and a mixture of non-hydrogenated, hydrogenated and fully hydrogenated polyisobutylene can also be used. Fully hydrogenated polyisobutylenes are preferably used. The non-hydrogenated polyisobutylenes contain an unsaturated end group due to the manufacturing process. Hydrogenated or partially hydrogenated polyisobutylenes are understood as meaning those polymers whose bromine number is lower by at least 20% compared to unhydrogenated polyisobutylene of the same number-average molecular mass. The bromine number for a non-hydrogenated polyisobutylene with Mn of 1300 g / mol is 14 g of bromine per 100 g of polyisobutylene. The bromine number in fully hydrogenated polyisobutylenes is below 7 g of bromine per 100 g of polyisobutylene. The bromine number is according to ASTM D2170-09 (reaproved 2018).

According to a further preferred embodiment, the polyisobutylene has a number average molecular weight from 115 to 10,000 g / mol, preferably from 500 to 5000 g / mol. The number average molecular weight is after ISO 16014-1 , Edition 2019-05 determined by means of gel permeation chromatography.

Component (C)

Component (C) is contained in the lubricant composition according to the invention in an amount of 1 to 18% by weight, preferably 4 to 14% by weight.

Component (C) is a lithium complex soap. Lithium complex soaps are understood as meaning mixtures of lithium salts of monofunctional carboxylic acids, preferably carboxylic acids containing 8 to 22 carbon atoms, particularly preferably carboxylic acids containing 14 to 20 carbon atoms, particularly preferably 12-hydroxystearic acid and / or stearic acid with the lithium salts of higher functional carboxylic acids, preferably dicarboxylic acids with 6 to 14 carbon atoms, particularly preferably azelaic acid, sebacic acid and dodecanedioic acid. Lithium complex soaps can additionally contain short-chain carboxylic acids such as acetic acid and lactic acid and / or phosphonic acids and / or boric acid as a further acid component.

Component (D)

Component (D) is a perfluoropolyether (PFPE) according to formula (I): R ₁ - (O-CF ₂ ) _v - (OC ₂ F ₄ ) _w - (OC ₃ F ₆ ) _x - (O-CFCF ₃ ) _y - (O-CF ₂ CF (CF ₃ )) _z -OR ₂ (I) where R ₁ and R _{2 are} identical or different and are selected from -CF ₃ , -C ₂ F ₅ , or -C ₃ F ₇ , v, w, x, y, z are integers from ≥ 0 to 500. PFPE Oils are marketed, for example, under the brand names Aflunox ^® , Krytox ^® , Fomblin ^® and Demnum ^® .

The PFPE oils are contained in the lubricant composition according to the invention in amounts of 5 to 70% by weight, preferably 15 to 50% by weight.

Component (E)

The lithium complex hybrid grease according to the invention can comprise further thickeners (E) in addition to the lithium complex thickener.

The further thickening agents (E) are contained in the lubricant composition according to the invention in amounts of 1 to 30% by weight, preferably 3 to 20% by weight.

The other thickeners (E) in the hybrid grease according to the invention are selected from the group consisting of Al complex soaps, metal single soaps of the elements of the first and second main groups of the periodic table without lithium, metal complex soaps of the elements of the first and second main groups of the periodic table without lithium , Bentonites, sulfonates, silicates, Aerosil, polyimides or PTFE or a mixture of the aforementioned thickeners. A particularly preferred further thickening agent is PTFE. The preferred PTFE is used as a micropowder, which is produced thermally or by irradiating high molecular weight PTFE with a reduction in molecular weight.

Component (F)

The hybrid greases according to the invention can contain further oils (F) which are contained in the lubricant composition according to the invention in amounts of 0 to 20% by weight, preferably 2 to 20% by weight.

Component (F) is selected from the group consisting of mineral oil, alkylated benzenes, alkylated naphthalenes, aliphatic carboxylic acid and dicarboxylic acid esters, fatty acid triglycerides, alkylated diphenyl ethers, phloroglucinic esters, estolides and / or poly-alpha-olefins, alpha-olefin copolymers, metallocene catalyzed polyalfa-olefins. Preferred further oils are alkylated diphenyl ether oils. Alkylated Diphenyletheröle be marketed under the brand name Hilube ^® by the company. Moresco. The alkyl groups contain between 10 and 20 carbon atoms. On average, between one and three alkyl groups are bound to the basic diphenyl ether unit.

Component (G)

The lubricant composition according to the invention further comprises from 0 to 10% by weight, preferably from 0.1 to 10% by weight, of additives (G), which are used individually or in combination.

Component (G) is selected from the group consisting of corrosion protection additives, antioxidants, wear protection additives, UV stabilizers. It is possible to use both additives that are soluble in component (A) and additives that are soluble in the PFPE oils of component (D) or also insoluble in both oil phases.

Examples of antioxidants are styrenated diphenylamines, diaromatic amines, phenolic resins, thiophenolic resins, phosphites, butylated hydroxytoluene, butylated hydroxyanisole, phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, octylated / butylated diphenylamine, di-alpha-tocopherol, di-alpha-tocopherol butyl-phenol or di-tert-butyl-4-methylphenol, benzene propanoic acid, sulfur-containing phenolic compounds, phenolic compounds and mixtures of these components.

Contain examples of suitable anti-corrosion additives, metal deactivators or ion complexing agents. These include triazoles, imidazolines, N-methylglycine (sarcosine), benzotriazole derivatives, N, N-bis (2-ethylhexyl) -ar-methyl-1H-benzotriazole-1-methanamine; n-Methyl-N (1-oxo-9-octadecenyl) glycine, mixture of phosphoric acid and mono- and diisooctyl esters reacted with (C _11-14 ) -alkylamines, mixture of phosphoric acid and mono- and diisooctyl esters reacted with tert-alkylamine and primary (C _12-14 ) amines, dodecanoic acid, triphenyl phosphorothionate and amine phosphates. Commercially available additives are the following: IRGAMET ^® 39, IRGACOR ^® DSS G, Amin O; Sarkosyl O ^® (Ciba), COBRATEC ^® 122, CUVAN ^® 303, VANLUBE ^® 9123, CI-426, CI-426EP, CI-429 and CI-498th

Further anti-wear additives are amines, amine phosphates, phosphates, thiophosphates and mixtures of these components. Most of the compounds mentioned have organic groups. The commercially available anti-wear additives include IRGALUBE ^® TPPT, IRGALUBE ^® 232, IRGALUBE ^® 349, IRGALUBE ^® 211 and ADDITIN ^® RC3760 Liq 3960, FIRC-SHUN ^® FG 1505 and FG 1506, NA-LUBE ^® KR-015FG, LUBEBOND ^® , FLUORO ^® FG, SYNALOX ^® 40-D, ACHESON ^® FGA 1820 and ACHESON ^® FGA 1810.

PFPE derivatives can also be included as additives. For example PFPE carboxylic acids, their metal and ammonium salts, their ester and amide derivatives. Further suitable substances are, for example, in WO01 / 72759A1 , WO 01 / 27916A1 , EP1070074B1 , EP1659165B1 and US2015011446A1 described.

Component (H)

Furthermore, the lubricant compositions according to the invention can contain solid lubricants (H) which are selected from the group consisting of BN, pyrophosphate, Zn oxide, Mg oxide, pyrophosphates, thiosulfates, Mg carbonate, Ca carbonate, Ca stearate, Zn Sulphide, Mo-sulphide, W-sulphide, Sn-sulphide, graphite, graphene, nano-tubes, SiO ₂ -modifications or a mixture thereof. The solid lubricants (H) are contained in the lubricant composition according to the invention in amounts of 0 to 10% by weight, preferably 2 to 5% by weight.

The lubricant composition according to the invention is used in the field of components, in particular in roller bearings, slide bearings, transport and timing chains in vehicle technology, rail vehicles, conveyor technology, film stretching systems, corrugated cardboard systems, roller bearings, fan bearings, bearings for traction motors, for the lubrication of bevel and bevel gears Helical gears, springs, screws and compressors, pneumatic components, fittings, and machine components and in systems where there is occasional, unintentional contact with food.

• 1 zeigt die Walkpenetration 60dT,
• 2 zeigt die Ölabscheidung, d.h. den Verlust des Öls aus dem Schmierfett.

The attached figures show the advantages of the lithium hybrid complex greases according to the invention:

• 1 shows the worked penetration 60dT,
• 2 shows the oil separation, ie the loss of oil from the grease.

The invention will now be explained in more detail with reference to the following examples.

Production of the lubricant compositions according to the invention

The production of the lubricant composition according to the invention is not restricted and can be carried out by any suitable method.

The production of the lubricant production according to the invention can for example be carried out in such a way that a base oil mixture is produced with components (A) and / or (B) and / or (F). The acids required for the lithium complex thickener (C) are melted down and an aqueous lithium hydroxide solution is added to this base oil mixture, which is completely or only partially placed in a suitable reaction vessel containing heating, cooling and stirring equipment. This creates a brew that contains the lithium soaps of the carboxylic acids. The acids can be added individually and neutralized, or the monocarboxylic acid is first added and neutralized and, in a second step, the higher-functionality carboxylic acid is added and neutralized. The brew is heated to 130 ° C to drive off water. The swelling of the thickener (lithium complex soap) is carried out by thermal treatment at 150 ° C to 210 ° C. The thermally treated brew is then cooled, whereby part of the base oil mixture can also be used. The components (D), (E), (G), (H) and possibly not used for the base oil mixture (A), (B) and (F) are added at a suitable temperature and pre-homogenized by stirring.

Solid lubricant additives that are soluble in the base oil mixture are added, for example, at temperatures above their melting point. Liquid additives or non-melting additives / solid lubricants / thickener components are added at temperatures below 80 ° C. The lithium complex hybrid grease produced in this way can be homogenized using suitable equipment such as three-roll mills, colloid mills or Gaulin.

In the method described in this way, the lubricant composition according to the invention is produced in one process. Alternatively, the addition of the PFPE oil (D) and the optional thickener component (E) in the process described above can be omitted, so that a lithium complex grease is produced. the Components (D) and (E) can be combined to a PFPE fat by stirring, homogenizing as described above. Lithium complex grease and PFPE grease can be combined in a second process step and the lubricant composition according to the invention can be produced therefrom with stirring and homogenization.

The production can also be carried out with continuous processes, whereby Li-complex ready-made soap in powder form can also be used.

example 1

Production of several lubricant compositions according to the invention, comparison with the lithium complex grease or PFPE / PTFE grease used for production, comparison with urea hybrid greases

Manufacturing

Lithium complex soap grease (fat A) and a PFPE / PTFE grease (fat B) are produced separately and the two fats A and B are mixed in different proportions, stirred and homogenized by rolling.

Fat A

A lithium complex grease consisting of 77% of a mixture of an alkyl diphenyl ether (100 mm ² / sec / 40 ° C) and trimellitic acid ester as well as fully hydrogenated polyisobutylene (fully hydrogenated, Mn approx. 1300 g / mol) is used as the base oil, with a viscosity at 40 ° C of 220 mm ² / sec, then 15% lithium complex of azelaic acid and 12-hydroxystearic acid and 8% of an additive package consisting of amine antioxidants, phosphates, thiadiazoles, triazoles and amine phosphates are added. The worked penetration is 270 1/10 mm (see table 1)

Fat B

A PFPE / PTFE grease is used, containing 70% a mixture of linear and branched PFPE, kinematic viscosity 200 mm ² / sec at 40 ° C, 26% PTFE micropowder, average particle size d 50 (laser diffraction, DIN ISO 9277) approx. 5 µm, specific surface (DIN ISO 9277) approx. 5 m ² / g, and 4% disodium sebacate produced as an anti-corrosion additive. The worked penetration is 286 1/10 mm (see table 1)

Example 1 (B1)

Mixture of fat A and fat B in a ratio of 10% by weight to 90% by weight.

Example 2 (B2)

Mixture of fat A and fat B in a ratio of 30% by weight to 70% by weight.

Example 3 (B3)

Mixture of fat A and fat B in a ratio of 50% by weight to 50% by weight.

Example 4 (B4)

Mixture of fat A and fat B in a ratio of 70% by weight to 30% by weight.

Example 5 (B5)

Mixture of fat A and fat B in a ratio of 90% by weight to 10% by weight.

Comparative example 1 (VG1)

A urea hybrid fat consisting of 50% by weight of fat B and 50% by weight of a urea fat is produced. The urea fat consists of a mixture of a trimellitic acid ester and a reaction product of octylamine and oleylamine with an MDI / TDI mixture as a urea thickener, as well Additives. The base oil viscosity is approx. 80 mm ² / sec. The worked penetration is 265 mm ² / sec (see Table 2)

Comparative example 2 (VG2)

A urea hybrid fat consisting of a complex ester, based on dimer acid, V 40 apr. 400 mm ² / sec at 40 ° C and branched PFPE oil with a kinematic viscosity of approx. 400 mm ² / sec in a mass ratio of 2: 1. The urea thickener is 10% contained and is a reaction product of octylamine and oleylamine with an MDI / TDI mixture. In addition, it contains 8% by weight of PTFE powder (as for fat B) and 5% by weight of soluble additives (antioxidants, amine phosphates). The worked penetration is 290 mm ² / sec (see Table 2)

Table 1 shows the general characteristics of the lithium complex hybrid greases according to the invention of Examples B1 to B5 and of greases A and B, Table 1 Parameter / grease Fat (B) B1 B2 B3 B4 B5 Fat (A) Walk penetration 60 dT [1/10 mm] (DIN ISO 2137) 286 279 254 253 262 273 270 Delta worked penetration after 100,000 dT 15th 28 31 45 44 39 45 [1/10 mm] (DIN ISO 2137) dropping point [° C] (DIN ISO 2176) > 300 > 300 > 300 > 300 > 300 294 > 300 Flow pressure [mbar] (-40 ° C) DIN 51805) 200 375 575 850 875 875 925 Flow pressure [mbar] (-50 ° C) (DIN 51805) 325 575 1025 > 1400 > 1400 > 1400 > 1400 Shear viscosity, at 25 ° C, shear rate 300 1 / s (DIN 53019 -1, -3) 6095 7557 7253 7210 6849 6106 5966 Loss of evaporation, 22h / 100 ° C 0.12 0.19 0.24 0.36 0.36 0.45 0.46 [% By weight] (DIN 58397) Oil separation, 24h / 150 ° C [wt%], (ASTM D 6184) 6.93 7.42 2.05 0.57 1.49 3.95 5.18 Oil separation, 72h / 150 ° C [wt%], (ASTM D 6184) 7.24 7.75 2.81 0.73 3.01 7.12 7.84 Oil separation, 168h / 40 ° C [wt%], (DIN 51817) 2.88 2.89 1.28 0.22 0.76 1.29 1.41 Static water resistance, 0 0 1 1 1 1 1 3h / 90 ° C (DIN 51807) copper corrosion, 24h / 120 ° C (DIN 51811) 2 1 -2 1 1 1 1 1

Table 2 shows the data of comparative examples VG1 to 2. Table 2 Parameter / grease VG1 VG2 Walk penetration 60 dT [1/10 mm] (DIN ISO 2137) 262 290 Delta worked penetration after 100,000 dT 47 43 [1/10 mm] (DIN ISO 2137) dropping point [° C] (DIN ISO 2176) 285 285 Flow pressure [mbar] (-40 ° C) (DIN 51805) 725 625 Flow pressure [mbar] (-50 ° C) (DIN 51805) 1200 1375 Shear viscosity, at 25 ° C, shear rate 300 1 / s (DIN 53019 -1, -3) 5913 11880 Evaporation loss, 22h / 100 ° C [wt%] (DIN 58397) 0.37 0.42 Oil separation, 24h / 150 ° C [wt%], (ASTM D 6184) 0.42 0.11 Oil separation, 72h / 150 ° C [wt%], (ASTM D 6184) 0.52 0.21 Oil separation, 168h / 40 ° C [wt%], (DIN 51817) 0.82 0.39 Static water resistance, 3h / 90 ° C (DIN 51807) 0 0 Copper corrosion, 24h / 120 ° C (DIN 51811) 1 1

As in 1 (Milled penetration of the compositions according to the invention) can be seen, particularly for compositions B2, B3 and B4, a lower milled penetration than for the two fats A and B used. This shows an unexpected synergistic effect due to the combination of the two types of fat to form the compositions according to the invention .

As in 2 (Oil separation of the compositions according to the invention in comparison) can be seen, the compositions according to the invention show a lower oil separation than the fats A and B from which they were produced. This behavior shows the unexpected synergistic effect caused by the composition according to the invention. The oil separation almost reaches the low values of the two comparison products VG1 and VG2. The reduction in oil separation in comparison to grease B shows the advantage over pure PFPE / PTFE greases.

The data also suggest that a desired oil separation behavior can be set by choosing the amount of fats A and B.

Determination of the evaporation loss

The lubricant compositions according to the invention were checked for their thermal stability and the results were compared primarily with those of the urea hybrid greases. For this purpose, investigations were carried out with regard to evaporation and viscosity under a temperature load of 5 g of fat weighed in in a stainless steel bowl at 200 ° C. The results are shown in Tables 3 and 4.

The evaporation loss is determined according to DIN standard 58397. Three stainless steel evaporation loss trays are required for each fat sample. The geometry of the bowls is described in the standard for determining the evaporation loss (DIN 58397). At the beginning, the respective empty weight of the bowls is determined. The three evaporation loss trays are then filled with the fat sample. It is important to ensure that the grease is applied without air bubbles. The surface is smoothed with a scraper and excess fat that has got into the recess on the edge of the bowl is removed. The dishes are then stored in a standard laboratory drying cabinet with convection with the flap closed at the appropriate test temperature (here 200 ° C). After the specified period of time (48h, 96h, 144h and 168h), the trays are removed from the drying cabinet and allowed to cool. The bowls are then weighed. The evaporation loss is determined from the difference between the initial weight and the measured value. A mean value is determined from the three individual _{values (V M} ). Together with the mean value of the three weights (A _M ), the evaporation loss can be calculated. V = (V _M / A _M ) * 100 [%]. After weighing, the dishes are placed in the drying cabinet until the next time. This is repeated until 168 hours have passed. Table 3 Loss of Evaporation Test 200 ° C B1 B2 B3 B4 B5 Loss of evaporation 48h / 200 ° C DIN 58397 Weight% 3.97 6.60 11.28 14.51 16.44 Evaporation loss 96h / 200 ° C DIN 58397 Weight% 5.27 8.75 15.22 19.69 22.17 Evaporation loss 144h / 200 ° C DIN 58397 Weight% 6.33 10.63 18.42 24.71 27.91 Evaporation loss 168h / 200 ° C DIN 58397 Weight% 7.15 12.35 21.15 28.98 33.11

Determination of the shear viscosity

The shear viscosity is determined according to DIN standard 53019 part 1 and part 3. The fat samples are transferred to three stainless steel evaporation-loss trays. The geometry of the bowls is described in the standard for determining the evaporation loss (DIN 58397). The dishes are then stored in a standard laboratory drying cabinet with circulation at the appropriate test temperature (here 200 ° C). After the specified period of time (48h, 96h, 144h and 168h), the trays are removed from the drying cabinet and allowed to cool. The starting value for the shear viscosity is determined for each grease before the thermal load.

The shear viscosity is measured with a device that is used as standard for determining the rheological parameters of lubricants (e.g. rheometer MCR 302 from Anton Paar).

A cone-plate system is used ( DIN EN ISO 3219 and DIN 53019 ), preferably with a measuring cone that has a diameter of 25 mm. The amount of fat sample required is based on typical amounts that are required for rheological measurements. The measurement duration is 120 s, of which 60 s are tempering or holding times. Measurements are made at a constant shear rate of 300 1 / s and a temperature of 25 ° C. The value, which can be read off after 90 s, represents the shear viscosity for the respective fat sample. The mean value is calculated from the three individual values determined and then given. Table 4 B1 B2 B3 B4 B5 Shear viscosity starting value DIN 53019-1 , -3 mPas 7557 7253 7210 6849 6106 Shear viscosity 48h / 200 ° C DIN 53019-1 , -3 mPas 6848 9857 9210 8651 5091 Shear viscosity 96h / 200 ° C DIN 53019-1 , -3 mPas 7671 10479 10292 9624 6587 Shear viscosity 144h / 200 ° C DIN 53019-1, -3 mPas 6800 11764 11112 9986 8917 Shear viscosity 168h / 200 ° C DIN 53019-1, -3 mPas 7494 10994 15452 9340 13623

The fats of Examples 1 to 5 were then compared with the fats of Comparative Examples 1 and 2 and the two individual fats (A) and (B) with regard to their thermal resistance. The results are shown in Tables 5 and 6. Table 5 Loss of Evaporation Test 200 ° C VG1 VG2 Fat A Fat B Loss of evaporation 48h / 200 ° C DIN 58397 Weight% 10.43 11.98 17.87 0.88 Evaporation loss 96h / 200 ° C DIN 58397 Weight% 13.47 14.17 24.75 1.11 Evaporation loss 144h / 200 ° C DIN 58397 Weight% 17.03 16.70 31.39 1.30 Evaporation loss 168h / 200 ° C DIN 58397 Weight% 20.67 19.18 37.66 1.45 Table 6 VG1 VG2 Fat A Fat B Shear viscosity starting value DIN 53019-1, -3 mPas 5913 11880 6095 5966 Shear viscosity 48h / 200 ° C DIN 53019-1, -3 mPas 9400 45976 7801 5800 Shear viscosity 96h / 200 ° C DIN 53019-1, -3 mPas 12844 100,000 8317 7104 Shear viscosity 144h / 200 ° C DIN 53019-1, -3 mPas 18286 100,000 7737 12093 Shear viscosity 168h / 200 ° C DIN 53019-1, -3 mPas 35172 100,000 8365 16025

The above results show that with the lithium complex hybrid greases according to the invention, the increase in shear viscosity is significantly lower than with the comparison products VG1 and VG2. VG2 shows a shear viscosity of 100,000 mPas after just 96 hours and is no longer lubricious. After a test time of 168 h, VG1 shows twice as high a shear viscosity than all compositions B1 to B5 according to the invention, see Table 4.

As expected, the PFPE / PTFE grease (grease B) shows the lowest evaporation losses in the test. Surprisingly, the shear viscosity of Examples B1, B2 and B4 according to the invention after a test time of 168 hours is lower than that of fat B and thus shows more favorable hardening behavior.

Overall, it has been shown that the hardening behavior of the lubricants according to the invention is more favorable at high temperatures than in the case of urea hybrid greases. Surprisingly, it was even found that with some of the compositions according to the invention even less hardening occurs than with a PFPE / PTFE grease. Surprisingly, it was also found that the oil separation behavior of the lubricants according to the invention can be set and thus adapted to different requirements by selecting certain mixing ratios of greases A (lithium complex grease) and B (PTFE / PFPE grease).

Example 2

Production of a lubricant according to the invention with different production processes

As already described, the lubricants according to the invention can be produced in various ways. With the “mixed in the kettle” variant, a lithium complex grease (fat C) and a PFPE / PTFE grease (fat D) are produced separately and then mixed in a kettle at a ratio of 40 to 60% by weight while stirring. The resulting lithium complex hybrid grease B6 is then homogenized using a three-roll mill.

In “in situ” production, the lithium complex grease is produced identically to fat C, but when it cools down, the components of fat D are added, so that the lubricant composition according to the invention is produced in one operation. The lubricant composition B6 according to the invention is also finally rolled.

Fat C

A lithium complex grease consisting of 80% by weight of a mixture of an alkyl diphenyl ether (100 mm ² / sec at 40 ° C.) and a trimellitic acid ester and fully hydrogenated polyisobutylene (fully hydrogenated, Mn approx. 1300 g / mol) is produced as the base oil, with gives a viscosity at 40 ° C of 100 mm ² / sec. 15% by weight of a lithium complex of azelaic acid and 12-hydroxystearic acid and 5% by weight of an additive package consisting of amine antioxidants and phosphates are provided. The fulled penetration is 327 1/10 mm.

Fat D

A PFPE / PTFE grease containing 65% by weight of a mixture of linear and branched PFPE, a kinematic viscosity of 145 mm ² / sec at 40 ° C., 33% by weight of PTFE micropowder, average particle size d 50 (laser diffraction, DIN ISO 9277 ) approx. 5 µm, specific surface ( DIN ISO 9277 ) approx. 5 m2 / g, and 2% by weight disodium sebacate as an anti-corrosion additive. The fulled penetration is 286 1/10 mm Table 7 Data of example B6 according to the invention according to example 2 Parameter / grease Mixed in the kettle Cooked in situ Walk penetration 60dT [1/10 mm] (DIN ISO 2137) 298 265 Drop point [° C] (DIN ISO 2176) > 300 277 Delta worked penetration according to 100000dT [1/10 mm] (DIN ISO 2137) 25th 36 Flow pressure -40 ° C [mbar] (DIN 51805) 550 725 Flow pressure -50 ° C [mbar] (DIN 51805) 1025 1250 Shear viscosity, at 25 ° C, shear rate 300 1 / s, [mPa * s] (DIN 53019-1, -3) 4392 5378 Evaporation loss, 24h / 150 ° C [% by weight] (DIN 58397) 0.46 0.50 Oil separation, 30h / 150 ° C [% by weight] (ASTM D 6184) 0.44 1.47 Oil separation, 72h / 150 ° C [% by weight] (ASTM D 6184) 0.53 2.11 Oil separation, 168h / 40 ° C [% by weight] (DIN 51817) 1.15 0.84 Static water resistance, 3h / 90 ° C (DIN 51807) 0 0 Copper corrosion 24h / 150 ° C (DIN 51811) 1 1 Table 8 Loss of evaporation test 220 ° C Mixed in the kettle Cooked in situ Loss of evaporation 48h / 220 ° C DIN 58397 Weight% 11.37 10.67 Evaporation loss 96h / 220 ° C DIN 58397 Weight% 15.84 15.15 Evaporation loss 144h / 220 ° C DIN 58397 Weight% 20.65 19.48 Evaporation loss 168h / 220 ° C DIN 58397 Weight% 23.02 21.65 Table 9 Mixed in the kettle Cooked in situ Shear viscosity starting value DIN 53019-1, -3 mPas 4392 5378 Shear viscosity 48h / 220 ° C DIN 53019-1, -3 mPas 6848 5823 Shear viscosity 96h / 220 ° C DIN 53019-1, -3 mPas 6449 7732 Shear viscosity 144h / 220 ° C DIN 53019-1, -3 mPas 10892 9342 Shear viscosity 168h / 220 ° C DIN 53019-1, -3 mPas 10927 11753

Both manufacturing variants deliver the same values within the scope of the measurement accuracy.

On the basis of the data available, B6 can be used as a lubricant according to production example 1 and production example 2 with both production variants.

It is thus shown that the lubricant compositions according to the invention can be produced using different processes.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0902828 B1 [0002]
• US 6063743 [0002]
• US 6018063 [0016]
• US 6316649 [0016]
• WO 2018/177588 A1 [0016]
• US 2013/0261325 A1 [0016]
• WO 0172759 A1 [0035]
• WO 0127916 A1 [0035]
• EP 1070074 B1 [0035]
• EP 1659165 B1 [0035]
• US 2015011446 A1 [0035]

Non-patent literature cited

• Synthetics, Mineral Oils And Bio Based Lubricants Chemistry And Technology, Second Edition, Editor Leslie R. Rudnik, Authors M. Casserino, J. Corthouts, CRC Press 2013, Pages 273-300 [0018]
• ASTM D2170-09 [0019]
• ISO 16014-1 [0020]
• DIN EN ISO 3219 [0065]
• DIN 53019 [0065]
• DIN 53019-1 [0065]
• DIN ISO 9277 [0074]

Claims (14)

Containing lithium complex hybrid grease (A) 70 to 7% by weight of an ester or an ester mixture selected from the group consisting of trimellitic acid esters which have linear or branched alkyl groups as alkoxy groups which contain 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms, the alkoxy group being the same or can be different, pyromellitic acid esters, hydrogenated or unhydrogenated dimer acids, estolides, (B) 0.5 to 20% by weight of non-hydrogenated, hydrogenated or fully hydrogenated polyisobutylene or mixtures thereof, (C) 1 to 18% by weight lithium complex soaps and (D) 5 to 70% by weight perfluoropolyether (PFPE). Lithium complex hybrid grease according to Claim 1 furthermore containing (E) 1 to 30% by weight of a further thickener. Further containing lithium complex hybrid grease according to one of the preceding claims (F) 0 to 20% by weight, preferably 2 to 20% by weight, of a further oil component. Further containing lithium complex hybrid grease according to one of the preceding claims (G) 0 to 10% by weight, preferably 0.1 to 10% by weight, of additives. Further containing lithium complex hybrid grease according to one of the preceding claims (H) 0 to 10% by weight, preferably 2 to 5% by weight, solid lubricant. Lithium complex hybrid grease according to one of the preceding claims, characterized in that the pyromellitic acid ester of component (A) is tetrakis (2-ethylhexyl) pyromellitate and the dimer acid is bis (2-ethylhexyl) dimerate. Lithium complex hybrid grease according to Claim 2 , characterized in that component (E) is selected from the group consisting of Al complex soaps, metal single soaps of the elements of the first and second main group of the periodic table without lithium, metal complex soaps of the elements of the first and second main group of the periodic table without lithium , Bentonites, sulfonates, silicates, Aerosil, polyimides, PTFE or a mixture thereof. Lithium complex hybrid grease according to Claim 3 , characterized in that component (F) is selected from the group consisting of mineral oil, alkylated benzenes, alkylated naphthalenes, aliphatic carboxylic acid and dicarboxylic acid esters, fatty acid triglycerides, alkylated diphenyl ethers, phloroglucinic esters, and / or poly-alpha-olefins, alpha-olefins -Copolymers, metallocene catalyzed polyalfa-olefins. Lithium complex hybrid grease according to Claim 4 , characterized in that component (G) is selected from the group consisting of corrosion protection additives, antioxidants, wear protection additives, UV stabilizers. Lithium complex hybrid grease according to Claim 5 , characterized in that component (H) is selected from the group consisting of BN, pyrophosphate, Zn oxide, Mg oxide, pyrophosphates, thiosulfates, Mg carbonate, Ca carbonate, Ca stearate, Zn sulfide, Mo sulfide, W sulfide, Sn sulfide, graphite, graphene, nano-tubes, SiO ₂ modifications or a mixture thereof. Use of the lithium complex hybrid grease according to one of the preceding claims for the lubrication of components, in particular in roller bearings, slide bearings, transport and control chains in vehicle technology, rail vehicles, conveyor technology, film stretching systems, corrugated cardboard systems, roller bearings, fan bearings, bearings of traction motors, for lubrication of bevel gears and spur gears, springs, screws and compressors, pneumatic components, fittings, and of machine components and in systems where there is occasional, unintentional contact with food. A method for lubricating or greasing components, in particular in roller bearings, plain bearings, transport and timing chains in vehicle technology and in rail vehicles, the method comprises: applying a lubricant composition to the surface of the component, the lubricant comprising: (A) 70 to 7 wt .-% of an ester or an ester mixture selected from the group consisting of trimellitic acid esters which, as alkoxy group, have linear or branched alkyl groups containing 6 to 18 Contain carbon atoms, preferably 8 to 14 carbon atoms, where the alkoxy groups can be the same or different, pyromellitic acid esters, hydrogenated or unhydrogenated dimer acids, estolides, (B) 0.5 to 20% by weight of unhydrogenated, hydrogenated or fully hydrogenated polyisobutylene or mixtures thereof, (C) 1 to 18% by weight lithium complex soaps; and (D) 5 to 70% by weight perfluoropolyether (PFPE). Process for the lubrication or greasing of roller bearings in continuous casting plants, transport roller bearings in continuous ovens, of open gear rings in rotary kilns, tube mills, drums and mixers, bearings in corrugated cardboard plants and film stretching plants, bearings in plants for the production and transport of food, the process comprises: Applying a lubricant composition to the surface of the component, the lubricant comprising: (A) 70 to 7% by weight of an ester or an ester mixture selected from the group consisting of trimellitic acid esters which have linear or branched alkyl groups as alkoxy groups which contain 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms, the alkoxy group being the same or can be different, pyromellitic acid esters, hydrogenated or unhydrogenated dimer acids, estolides, (B) 0.5 to 20% by weight of non-hydrogenated, hydrogenated or fully hydrogenated polyisobutylene or mixtures thereof, (C) 1 to 18% by weight lithium complex soaps and (D) 5 to 70% by weight perfluoropolyether (PFPE). Process to reduce the hardening of lubricating greases at 200 ° C and / or to reduce the oil separation of lubricating greases on roller bearings in continuous casting plants, transport roller bearings in continuous furnaces, of open gear rings in rotary kilns, tube mills, drums and mixers, bearings in corrugated cardboard plants and film stretching plants, bearings in plants for the production and transport of food, the process comprises: Applying a lubricant composition to the surface of the component, the lubricant comprising: (A) 70 to 7% by weight of an ester or an ester mixture selected from the group consisting of trimellitic acid esters which have linear or branched alkyl groups as alkoxy groups which contain 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms, the alkoxy group being the same or can be different, pyromellitic acid esters, hydrogenated or unhydrogenated dimer acids, estolides, (B) 0.5 to 20% by weight of non-hydrogenated, hydrogenated or fully hydrogenated polyisobutylene or mixtures thereof, (C) 1 to 18% by weight lithium complex soaps and (D) 5 to 70% by weight perfluoropolyether (PFPE).

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