DE102010006745A1 - Greases containing lignosulfonate, their preparation and use - Google Patents

Abstract

The invention relates to calcium lignosulfonate-containing greases containing a base oil, calcium soaps, calcium lignosulfonate having average molecular weights (weight average) of greater than 10,000 g / mol and optionally further Erdalkaliligninsulfonaten produced under heating to greater than 120 ° C with reaction and expulsion of low-boiling components Preparation of a base fat and cooling and addition of base oil and optionally additives with mixing, a corresponding method and the use of calcium lignosulfonate-containing greases.

Description

The invention relates to a process for the preparation of calcium lignosulfonate greases, such lubricating greases and their use

Lignin is a complex polymer based on phenylpropane units, which are interlinked with each other with a range of different chemical bonds. Lignin occurs in plant cells together with cellulose and hemicellulose. Lignin itself is a cross-linked macromolecule with average molecular weights of z. B. greater than 10,000 g / mol (weight average).

As monomer building blocks of lignin, essentially 3 types of monolignol monomers can be identified, which differ from each other in the degree of methoxylation. These are p-cumaryl alcohol, coniferyl alcohol, and sinapyl alcohol. These lignols are incorporated into the lignin structure in the form of hydroxyphenyl (H), guaiacyl (G), and syn-ring (S) units. Naked plants (gymnosperms) such. B. Pines contain overwhelmingly G units and low levels of H units. All lignins contain small amounts of incomplete or modified monolignols. The primary function of lignins in plants is to confer mechanical stability by cross-linking the plant polysaccharides. Lignin represents about 1/3 of the dry mass of wood and roughly represents 30% of the non-fossil organic carbon mass on Earth. It is the third most common organic material after cellulose and chitin and thus also a very readily available renewable raw material for industrial products.

Lignosulfonate is a by-product of papermaking with the sulfite process. In this process, comminuted wood chips are heated under pressure (for example 5 to 7 bar) for about 7 to 15 hours in the presence of calcium bisulfite liquor and then the lignosulfonic acid in the form of calcium lignosulfonate is removed from the lignocellulose by a washing and precipitation process. Instead of calcium hydrogen sulfite, it is also possible to use magnesium, sodium or ammonium sulfite bases, which leads to the corresponding magnesium, sodium and ammonium salts of lignosulfonic acid. Evaporation of the wash liquor gives powdered lignosulfonates. The annual worldwide production of lignosulfonates amounts to approx. 55 million tons.

Sodium, calcium and magnesium lignosulfonates are widely used as a base for the plasticization and liquefaction of concrete and mortar. Another use find lignosulfonates as Pelletierhilfsmittel in the concentrated feed industry and in other areas as a dispersant or complexing agent.

Tribochemically acting extreme pressure (high pressure) and anti-wear (EP / AW) additives used in today's grease formulations account for a not inconsiderable amount of the formulation costs and are thus often the price-driving factor for greases.

Many of these additives are prepared by elaborate multi-step synthesis procedures and their use is limited by the toxicological side effect that occurs in many cases, both in the way they are used and in their use concentration in the final formulation. In some applications, e.g. As in constant velocity universal joint or in slow-moving and highly loaded bearings can not be avoided by liquid additives lack of lubrication conditions or a touch of the friction partners. In these cases, solid lubricants based on inorganic compounds (eg Ca and Zn phosphate salts), plastic powders (eg PTFE) or metal sulfides (eg MoS ₂ ) have been used in the past practice. These components are often expensive and have a significant impact on the overall cost of a lubricant formulation.

Previous practice in the production of grease is the addition of these additives in a second, downstream of the actual chemical reaction process of thickening process step. In this additive, especially solid lubricants must be distributed by intensive mixing and shearing processes with increased mechanical effort homogeneously in the relatively high viscosity grease to achieve their optimum effect.

From today's perspective, the following often proves to be disadvantageous and has given rise to the present invention. Common lubricant additives and solid lubricants are based i. d. R. not on renewable resources and are often difficult to biodegrade.

In addition, most common anti-wear additives and friction-reducing lubricant additives require a complex synthetic chemistry and therefore represent a major In particular, when using solid lubricants for highly loaded friction points dominate therefore comparatively expensive materials such as MoS ₂ or PTFE.

Task / Advantage of the invention

The object of the invention is therefore to avoid the disadvantages of the prior art described above, and to provide lignosulfonates both as a cost structurant and as a wear-protective, friction-reducing and anti-aging additive in lubricating greases and at the same time to provide good water resistance of the greases.

Due to the presence of lignosulfonate, the use of other common lubricant additives and solid lubricants, in particular MoS ₂ , can be minimized or even dispensed with.

Summary of the invention

The invention is characterized by the independent claims. Preferred embodiments are subject of the dependent claims or described below.

• – Grundöl
• – Fettsäuren und/oder deren Ester oder deren Salze, wobei das Fettsäuresalz zumindest teilweise ein Calciumsalz ist, zur Herstellung von Seifen enthaltend zumindest Calciumseifen,
• – ggf. organische und/oder anorganische Komplexierungsmitteln
• – Erdalkalihydroxide, wobei die Erdalkalihydroxide zumindest CaOH umfassen,
• – ggf. Wasser (z. B. als Teil der Hydroxide) und
• – Ca-Ligninsulfonat mit mittleren Molekulargewichten (Gewichtsmittel) von größer 10000 g/mol.

um durch Erhitzen das Austreiben niedrig siedender Komponenten, bei Einsatz von Estern, und zumindest eine Umsetzung des Erdalkalihydroxids mit den Fettsäuren und/oder deren Estern und dem Ligninsulfonat zu bewirken, einschließlich der Umsetzung mit den Komplexierungsmitteln, soweit mit den Erdalkalihydroxiden umsetzbare Komplexierungsmittel eingesetzt werden, zur Bildung einer Verdickerstruktur im Grundöl.According to the method on which the present invention is based, a precursor (base fat) is first prepared by joining at least one of them

• - base oil
• Fatty acids and / or their esters or their salts, where the fatty acid salt is at least partially a calcium salt, for the preparation of soaps containing at least calcium soaps,
• - If necessary, organic and / or inorganic complexing agents
• Alkaline earth hydroxides, the alkaline earth hydroxides comprising at least CaOH,
• Optionally water (eg as part of the hydroxides) and
• Ca lignosulfonate having weight average molecular weights of greater than 10,000 g / mol.

to effect by heating the expulsion of low-boiling components, using esters, and at least one reaction of the alkaline earth metal hydroxide with the fatty acids and / or their esters and the lignosulfonate, including the reaction with the complexing agents, as far as usable with the alkaline earth metal hydroxides complexing agents, to form a thickener structure in the base oil.

Low boiling components are those components which boil at about 100 ° C at normal pressure, such as water or C 1 to C 4 alcohols.

Preferably, to produce the base fat to temperatures of about 120 ° C or better above 180 ° C heated. The conversion to the base fat takes place in a heated reactor, which can also be designed as an autoclave or vacuum reactor.

Subsequently, in a second step by cooling, the formation of the thickener structure is completed and, if appropriate, further constituents, such as additives and / or base oil, are added to set the desired consistency or the desired property profile. The second step may be carried out in the reactor of the first step, but preferably the base grease from the reactor is transferred to a separate stirred tank for cooling and mixing in the optionally further constituents,

If necessary, the resulting grease is homogenized, filtered and / or vented.

There are preferably Ca / Li, Li / Ca and calcium thickened normal and complex soap fats are used in which calcium lignosulfonate is added before the reaction phase for the production of base grease and incorporated through a thermal process in the grease structure that it in very homogeneous oil-insoluble form and leads to high dropping point temperatures.

The use of alkaline earth salts, preferably calcium salts, both on the side of the fatty acid salts and the lignosulfonate ensures that no salification takes place both in the preparation of the base fat and in the application.

The salification, in particular to the sodium salts, must be prevented in order to obtain a lignosulfonate-containing grease with good water resistance and at the same time a high dropping point. Therefore, avoid the use of sodium lignosulfonate and sodium hydroxide. Under water resistance is Understand that fat according to test DIN 51807-1 (Issue: 1979-04) is not emulsified by water or corresponds to the evaluation level 1-90 (test at 90 ° C). Under water resistance it is also understood that fat according to test DIN 51807-2 (Edition 1990-03) the rating level 1-80 (test at 80 ° C) corresponds.

By the simultaneous use of an excess of alkali in the form of excess calcium hydroxide and optionally additionally calcium acetate or other calcium salts as a complexing agent to ensure that even small residues of free sulfonic acid groups are neutralized in the lignosulfonic acid and removed hygroscopic and water-emulsifying and corrosive action. By a high process temperature of greater than 120 ° C, in particular greater than 180 ° C is additionally ensured that the residual moisture still registered in the lignosulfonate is completely evaporated from the reaction medium and possibly neutralized components of the lignosulfonate are neutralized by calcium hydroxide.

Suitable base oils are customary lubricating oils which are liquid at room temperature. The base oil preferably has a kinematic viscosity of 20 to 2500 mm ² / s, in particular 40 to 500 mm ² / s at 40 ° C.

The base oils can be classified as mineral oils or synthetic oils. As mineral oils z. B. Regarding naphthenic and paraffinic mineral oils, according to API Group I classification. Chemically modified low aromatics and low sulfur mineral oils with low content of saturated compounds and improved viscosity / temperature behavior over Group I oils, classified according to API Group II and III, are also suitable.

Synthetic oils which may be mentioned are polyethers, esters, polyalphaolefins, polyglycols and alkylaromatics and mixtures thereof. The polyether compound may have free hydroxyl groups, but may also be fully etherified or end groups esterified and / or prepared from a starting compound having one or more hydroxy and / or carboxyl groups (-COOH). Also possible are polyphenyl ethers, optionally alkylated, as sole components or even better as mixed components. Suitable for use are esters of an aromatic di-, tri- or tetracarboxylic acid, with one or in mixture C2 to C22 alcohols, esters of adipic acid, sebacic acid, trimethylolpropane, neopentyl glycol, pentaerythritol or dipentaerythritol with aliphatic branched or unbranched, saturated or unsaturated C2 to C22-carboxylic acids, C18 dimer acid esters with C2 to C22 alcohols, complex esters, as individual components or in any desired mixture.

The soaps produced are either pure calcium soaps or mixtures containing calcium soaps, in particular besides calcium soaps also lithium soaps and / or aluminum soaps, one or more saturated or unsaturated mono-carboxylic acids with 10 to 32 carbon atoms, optionally substituted, in particular with 12 to 22 carbon atoms, particularly preferred corresponding hydroxycarboxylic acids. Suitable carboxylic acids are, for. For example, lauric acid, myristic acid, palmitic acid, oleic acid, stearic acid or behenic acid and preferably 12-hydroxystearic acid. Instead of the free acid group and corresponding lower alcohol esters can be used with saponification, z. B. corresponding triglycerides and the methyl, ethyl, propyl, isopropyl or sec-butyl ester of acid / hydroxy acid to achieve a better dispersion.

The soap becomes a complex soap by the presence of a complexing agent. Complex soaps have increased drip points, from z. B. greater than 200 ° C ( DIN ISO 2176 ).

• (a) das Alkalisalz (bevorzugt Lithiumsalz) ausgenommen Natriumsalz, Erdalkalisalz (bevorzugt Calciumsalz) oder Aluminiumsalz einer gesättigten oder ungesättigten Mono-Carbonsäure oder auch Hydroxycarbonsäuren mit 2 bis 8, insbesondere 2 bis 4 Kohlenstoffatomen oder einer Di-Carbonsäure mit 2 bis 16, insbesondere 2 bis 12 Kohlenstoffatomen, jeweils ggf. substituiert, und/oder
• (b) das Alkali- und/oder Erdalkalisalz der Borsäure und/oder Phosphorsäure, insbesondere deren Umsetzungsprodukte mit LiOH und/oder Ca(OH)₂.

Complexing agents in the context of the present invention are:

• (A) the alkali metal salt (preferably lithium salt) excluding sodium salt, alkaline earth metal salt (preferably calcium salt) or aluminum salt of a saturated or unsaturated mono-carboxylic acid or hydroxycarboxylic acids having 2 to 8, in particular 2 to 4 carbon atoms or a di-carboxylic acid having 2 to 16, in particular 2 to 12 carbon atoms, each optionally substituted, and / or
• (b) the alkali and / or alkaline earth metal salt of boric acid and / or phosphoric acid, in particular their reaction products with LiOH and / or Ca (OH) ₂ .

The complexing agent (a) is preferably exclusively a calcium salt, in particular if it is used as calcium acetate for the preparation of the base fat. Particularly suitable mono-carboxylic acids are acetic acid and propionic acid. Also suitable are hydroxybenzoic acids such as parahydroxybenzoic acid, salicylic acids, 2-hydroxy-4-hexylbenzoic acid, metahydroxybenzoic acid, 2,5-dihydroxybenzoic acid (gentisic acid), 2,6-dihydroxybenzoic acid (gammaresorcylic acid) or 4-hydroxy-4- methoxybenzoic. Particularly suitable dicarboxylic acids are adipic acid (C ₆ H ₁₀ O ₄ ), sebacic acid (C ₁₀ H ₁₈ O ₄ ), azelaic acid (C ₉ H ₁₆ O ₄ ) and / or 3-tert-butyl adipic acid (C ₁₀ H ₁₈ O ₄ ).

As borate (b), for example, metaborate, diborate, tetraborate or orthoborate, such as. As monolithium orthoborate or calcium orthoborate, are used. Suitable phosphates are alkali metal (preferably lithium) and alkaline earth metal (preferably calcium) dihydrogen phosphate, hydrogen phosphate or pyrophosphate.

In addition, bentonites such as montmorillonite (whose sodium ions may be exchanged or partially exchanged with ammonium ions), aluminosilicates, clays, silicic acid (eg Aerosil), oil-soluble polymers (eg polyolefins, poly (meth ) Acrylates, Polyisiobutylene, polybutenes or PS) or di- and polyureas are used as co-thickener. The bentonites, aluminosilicates, clays, silicic acid and / or oil-soluble polymers may be added to make the base fat or added later as an additive in the second step. The di- and polyureas can be added as an additive.

The compositions according to the invention optionally further contain additives as additives. Usual additives in the context of the invention are antioxidants, anti-wear agents, corrosion inhibitors, detergents, dyes, lubricity improvers, viscosity additives, friction reducers and high-pressure additives.

• – Antioxidationsmittel wie Amin-Verbindungen (z. B. Alkylamine oder 1-Phenyl-aminonaphthalin), aromatische Amine, wie z. B. Phenylnaphtylamine oder Diphenylamine, Phenol-Verbindungen (z. B. 2.6-Di-tert-butyl-4-methylphenol), Sulfurantioxidantien, Zinkdithiocarbamat oder Zinkdithiophosphat;
• – Hochdruckadditive wie organische Chlorverbindungen, Schwefel, Phosphor oder Calciumborat, Zinkdithiophosphat, organische Bismuthverbindungen;
• – die ”Öligkeit” verbessernde Wirkstoffe wie C2- bis C6-Polyole, Fettsäuren, Fettsäureester oder tierische oder pflanzliche Öle;
• – Antikorrosionsmittel wie z. B. Petroleumsulfonat, Dinonylnaphtalinsulfonat oder Sorbitanester;
• – Metalldeaktivatoren wie z. B. Benzotriazol oder Natriumnitrit;
• – Viskositätsverbesserer wie z. B. Polymethacrylat, Polyisobutylen, oligo-Dec-1-ene, und Polystyrole.
• – Verschleißschutzadditive und Reibungsminderer wie Organomolybdänkomplexe (OMC), Molybdän-di-alkyl-dithiophosphate, Molybdän-di-alkyl-dithiocarbamate oder Molybdänsulfid-di-alkyl-dithiocarbamate, insbesondere Molybdän-di-n-butyldithiocarbamat und Molybdändisulfid-di-alkyldithiocarbamat (Mo₂O_mS_n(dialkylcarbamat)₂ mit m = 0 bis 3 und n = 4 bis 1),
• – Reibungsminderer wie z. B. funktionelle Polymere wie z. B. Oleylamide, organische Verbindungen auf Polyether- und Amidbasis, z. B. Alkylpolyethylenglykoltetradecylenglykolether.

Examples include:

• Antioxidants such as amine compounds (eg., Alkylamine or 1-phenyl-aminonaphthalene), aromatic amines, such as. Phenylnaphthylamines or diphenylamines, phenolic compounds (e.g., 2,6-di-tert-butyl-4-methylphenol), sulfur dioxide antioxidants, zinc dithiocarbamate or zinc dithiophosphate;
• High pressure additives such as organic chlorine compounds, sulfur, phosphorus or calcium borate, zinc dithiophosphate, organic bismuth compounds;
• - the "oiliness" improving agents such as C2 to C6 polyols, fatty acids, fatty acid esters or animal or vegetable oils;
• - Anticorrosion agents such. Petroleum sulfonate, dinonylnaphthalenesulfonate or sorbitan esters;
• - Metal deactivators such. Benzotriazole or sodium nitrite;
• - Viscosity improvers such. Polymethacrylate, polyisobutylene, oligo-dec-1-ene, and polystyrenes.
• Anti-wear additives and friction modifiers such as organomolybdenum complexes (OMC), molybdenum di-alkyl dithiophosphates, molybdenum di-alkyl dithiocarbamates or molybdenum sulfide di-alkyl dithiocarbamates, in particular molybdenum di-n-butyl dithiocarbamate and molybdenum disulfide di-alkyl dithiocarbamate (Mo ₂ O _m S _n (dialkylcarbamate) ₂ with m = 0 to 3 and n = 4 to 1),
• - friction reducer such. B. functional polymers such. As oleylamides, organic compounds based on polyether and amide, z. B. Alkylpolyethylenglykoltetradecylenglykolether.

In addition, the grease compositions of this invention contain conventional anti-corrosive, oxidative, and anti-metallope additives which act as chelates, radical scavengers, UV transducers, reaction layer formers, and the like.

As solid lubricants z. As polymer powder such as polyamides, polyimides or PTFE, graphite, metal oxides, boron nitride, metal sulfides such. As molybdenum disulfide, tungsten disulfide or mixed sulfides based on tungsten, molybdenum, bismuth, tin and zinc, inorganic salts of alkali and alkaline earth metals, such as. As calcium carbonate, sodium and calcium phosphates are used. Solid lubricants can be divided into the following four groups: layered structure compounds such as molybdenum disulfide and tungsten disulfide, graphite, hexagonal boron nitride, and some metal halides; oxidic and hydroxidic compounds of the transition and alkaline earth metals or their carbonates or phosphates; soft metals and / or plastics. The desired advantageous lubrication properties can be adjusted by the use of lignosulfonates, without having to use solid lubricants. In many cases, these can be dispensed with completely or at least can be significantly minimized. As far as solid lubricants are used graphite can be used advantageously.

As lignosulfonate calcium lignosulfonates having molecular weight (Mw, weight average) of greater than 10,000, in particular greater than 12,000 or even greater than 15,000 g / mol are used, for. B. from greater than 10,000 to 65,000 g / mol or 15,000-65,000 g / mol, in particular 2 to 12 wt .-%, in particular 4 to 10 wt .-%, sulfur (calculated as elemental sulfur) and / or 5 to 15 Wt .-%, in particular 8 to 15 wt .-% calcium (calculated Ca) included. In addition to calcium lignosulfonates, other alkaline earth lignin sulfonates may additionally be used. The weight average molecular weight is z. B. determined by size exclusion chromatography. A suitable method is the SEC-MALLS method like described in the article of GE Fredheim, SM Braaten and BE Christensen, "Comparison of molecular weight and molecular weight distribution of softwood and hardwood lignosulfonates" published in "Journal of Wood Chemistry and Technology", Vol. 23, No. 2, pages 197-215, 2003 and the article "Molecular weight determination of lignosulfonates by size exclusion chromatography and multi-angle laser scattering" of the same authors, published in Journal of Chromatography A, Volume 942, Issue 1-2, 4 January 2002, pages 191-199 (Mobile Phase: Phosphate). DMSO-SDS, stationary phase: Jordi-glucose DVB as described under 2.5) , Suitable calcium lignosulfonates are, for. As the commercially available products Norlig 11 D and Borrement Ca 120 from Borregard Lignotech.

• a) 55 bis 92 Gew.-%, insbesondere 70 bis 85 Gew.-%, des Grundöls,
• b) 0 bis 40 Gew.-%, insbesondere 2 bis 10 Gew.-%, Additive,
• c) 3 bis 40 Gew.-%, insbesondere 5 bis 20 Gew.-%, Seifen und
• d) 0 bis 20 Gew.-%, insbesondere 0,5 bis 10 Gew.-%, Komplexierungsmittel, und
• e) überschüssiges Ca(OH)₂, vorzugsweise 0,01 bis 2 Gew.-%,
• f) 0,5 bis 50, insbesondere 2 bis 15 Gew.-%, und besonders bevorzug 3 bis 8 Gew.-% Ligninsulfonat insbesondere Calciumligninsulfonat,

jeweils bezogen auf die gesamte Zusammensetzung, wobei die Komponenten und deren Vorzugsvarianten oben definiert sind.The lubricating grease according to the invention is characterized by the following composition:

• a) 55 to 92% by weight, in particular 70 to 85% by weight, of the base oil,
• b) 0 to 40% by weight, in particular 2 to 10% by weight, of additives,
• c) 3 to 40 wt .-%, in particular 5 to 20 wt .-%, soaps and
• d) 0 to 20 wt .-%, in particular 0.5 to 10 wt .-%, complexing agent, and
• e) excess Ca (OH) ₂ , preferably 0.01 to 2 wt .-%,
• f) from 0.5 to 50, in particular from 2 to 15,% by weight, and particularly preferably from 3 to 8% by weight of lignin sulphonate, in particular calcium lignosulphonate,

in each case based on the entire composition, wherein the components and their preferred variants are defined above.

It has now been found that lignosulfonates act as structure formers for water-resistant lubricating greases with simultaneous properties as solid lubricant or wear protection additive and aging stabilizer. At the same time, surprisingly synergistic effects of lignin sulfonate with other solid lubricants, e.g. B. observed with graphite or calcium carbonate.

It has also been found that lignosulfonates are multifunctional components for lubricants. Due to their high number of polar groups and aromatic structures, their polymeric structure and their low solubility in all types of lubricating oils, lignosulfonates are not only suitable as thickener constituents but also as solid lubricants in lubricating greases and lubricating pastes. In addition, the sulfur content promotes the EP / AW effect in the lubricating greases and the phenolic structures provide an age-inhibiting effect.

It is believed that the lignosulfonate structure has a predominantly planar structure due to its large number of polymeric and polar aromatic units. Thus, under the action of external frictional and shear forces, these can deposit very well in layer structures on metal surfaces, because the aromatic nuclei of the lignin sulfonate interact in an associative manner with the metal surface and efficiently and permanently separate metallic friction partners even at high loads or pressures.

If calcium lignosulfonate is added even before the start of the reaction phase in the production of soap thickeners, in particular calcium complex soaps, these on the one hand produce an additional thickening effect and a high dropping point and on the other hand they improve the wear protection and lubricating effects of corresponding lubricant formulations. Therefore, it is beneficial for the distribution and effect of additives and solid lubricants, if they are chemically or mechanically integrated during the reaction phase as an additional structural element in situ in the thickener structure.

For the production of soap greases with high dripping points must in the prior art in many cases specially treated and expensive fatty acids such. B. 12-Hydroxistearinsäure or special complexing agents such. As borates or salts of acetic acid, sebacic acid and azelaic acid are used, which have no or only a small simultaneous effect as anti-wear and friction-reducing additive. By using Ca lignosulfonates, the use of said components can be reduced or even dispensed with. Furthermore, the use of Ca lignosulfonates offers the opportunity to formulate high performance lubricating fats based on renewable raw materials and to dispense with an environmentally harmful additive chemistry.

Thickening oils consisting of unaltered or slightly modified native fatty acid esters with metal soaps based on animal or vegetable fatty acids and lignosulfonates used as the only other thickener and simultaneous additive component, we obtain greases, except for the calcium hydroxide used for metal soaps exclusively based on renewable Raw materials produced were. These are resistant to aging and wear, as well as increasing the load stress and reducing friction by the use of lignosulfonates as thickener component.

The greases according to the invention are particularly suitable for use in or for constant velocity universal joint, rolling bearings and gearbox.

As far as the base oils used from biodegradable esters such. As those containing predominantly renewable raw materials exist, the greases are also suitable for loss lubrication in the environmentally sensitive area (eg., In mining or agriculture).

In the particular case of lubrication maintenance-free constant velocity universal joint shafts was first formulated using calcium lignosulfonate a grease, which leads in contrast to the prior art entirely without MoS ₂ and other organic and inorganic molybdenum compounds to high lifetimes and good efficiencies.

In addition, the omission of other additives as Reibwertminderer, Fresslast- and wear protection causes a very good compatibility with commercially available Gelenkwellenfaltenbalgmaterialien such as chloroprene rubber and thermoplastic polyether esters. Since the sulfur containing lignosulfonate is bound by thermally stable sulfonate groups, unlike the sulfur bound in conventional additives, it can only be released at very high temperatures or activation energies, such as occur in grease applications only with highly loaded tribocontacts. Thus, a subsequent vulcanization or crosslinking of rubber materials is largely prevented by sulfur released from the aged lubricant.

The use of calcium lignosulfonate in overbased excess calcium hydroxide grease formulation prevents free lignin sulfonic acid from exerting a hydrolytic effect on bellows materials such as thermoplastic polyether esters.

It is a particular aspect of the present invention to arrive at cost-optimized Schmierfetfformulierungen for highly loaded lubrication points, in particular in constant velocity joints, which has a good compatibility with bellows, constructed of z. As thermoplastic polyether esters (TPE) and chloroprenes (CR), while high efficiency, low wear and long life.

Preparation Examples

Example A (Comparative Example)

Into a reactor, 958 g of tallow fatty acid, 958 g of beef tallow, 958 g of calcium acetate, 27.7 g of trisodium phosphate, 27.7 g of calcium borate and 358 g of calcium hydroxide were placed in 12000 g of a base oil mixture, and 150 ml of water were added. The batch was heated in a predetermined temperature program to 198 ° C with stirring while the added water and the water of reaction evaporated. In the cooling phase, additives (see table) were added to the batch at certain temperatures.

After adjusting the batch to the desired consistency by adding 3700 g of the base oil mixture, the final product was homogenized on a toothed colloid mill. The fat thus obtained is z. B. suitable as constant velocity universal joint grease.

Example B:

Into a reactor were placed in 14000 g of a base oil mixture 460 g tallow fatty acid, 445 g beef tallow, 460 g calcium acetate, 27.7 g trisodium phosphate, 27.7 g calcium borate and 168 g calcium hydroxide and 920 g calcium lignosulfonate (Norlig 11 D powder from Borregard Lignotech) and 150 ml of water. The batch was heated in a predetermined temperature program to 208 ° C with stirring, thereby evaporating the added water and the reaction water. In the cooling phase, additive was added to the batch at certain temperatures (see table). After setting the batch to the desired consistency by adding 3450 g of the base oil mixture, the final product was homogenized on a Zahnkolloidmühle. The fat thus obtained is z. B. suitable as constant velocity universal joint grease.

Example C (Comparative Example)

Into a reactor, 800 g of 12-hydroxistearic acid, 288 g of sebacic acid, 388 g of calcium acetate and 157.3 g of calcium hydroxide were placed in 5000 g of a base oil mixture. 64 g of LiOH.H ₂ O was dissolved in 250 ml of water and added. The mixture was heated in a predetermined temperature program to 200 ° C with stirring, thereby evaporating the added water and the reaction water. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 3116 g of the base oil mixture, the final product was homogenized by tooth colloid mill. The fat thus obtained is z. B. suitable as a rolling bearing grease.

Example D:

Into a reactor were placed in 5000 g of a base oil mixture 600 g of 12-hydroxistearic acid, 216 g of sebacic acid, 291 g of calcium acetate and 720 g of calcium hydroxide and 300 g of calcium lignin sulfonate (Norlig 11D powder from Borregard Lignotech). 48 g of LiOH × H ₂ O was dissolved in 250 ml of water and added. The mixture was heated in a predetermined temperature program to 200 ° C with stirring, thereby evaporating the added water and the reaction water. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 3116 g of the base oil mixture, the final product was homogenized by tooth colloid mill. The fat thus obtained is z. B. suitable as a rolling bearing grease.

Example E (Comparative Example)

Into a reactor, 1380 g of tallow fatty acid, 1360 g of beef tallow, 80 g of trisodium phosphate, 80 g of calcium borate, 1400 g of calcium acetate and 493 g of calcium hydroxide were placed in 12000 g of a base oil mixture, and 150 ml of water were added. The batch was heated in a predetermined temperature program to 230 ° C with stirring, thereby evaporating the added water and the water of reaction. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 3125 g of the base oil mixture, the final product was homogenized by tooth colloid mill. The fat thus obtained is z. B. suitable as a rolling bearing grease.

Example F:

Into a reactor 1260 g of tallow fatty acid, 1240 g of beef tallow, 80 g of trisodium phosphate, 80 g of calcium borate, 1278 g of calcium acetate, 493 g of calcium hydroxide and 885 g of calcium lignosulfonate (Norlig 11D Powder from Borregard Lignotech) were placed in 12000 g of a base oil mixture and 150 ml of water were added , The batch was heated in a predetermined temperature program to 225 ° C with stirring, thereby evaporating the added water and the water of reaction. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 3125 g of the base oil mixture, the final product was homogenized by tooth colloid mill. The fat thus obtained is z. B. suitable as a rolling bearing grease.

Example G (Comparative Example)

Into a reactor were placed in 3500 g of methyl oleate ester, 975 g of calcium 12-hydroystearate, 225 g of calcium acetate and 15 g of calcium borate. The batch was heated in a predetermined temperature program to 200 ° C with stirring. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 180 g of methyl oleate ester, the final product was homogenized on a 3-roll mill. The resulting grease is based on predominantly renewable raw materials.

Example H:

A reactor was charged with 1965 g of methyl oleate ester, 841 g of calcium 12-hydroystearate, 219.5 g of calcium acetate, 15 g of calcium borate and 418 g of calcium lignosulfonate (Norlig 11D powder from Borregard Lignotech). The batch was heated in a predetermined temperature program to 200 ° C with stirring. In the cooling phase, additives were added to the batch at certain temperatures. After adjusting the batch to the desired consistency by adding 1684 g of trimethylolproprantrioleate ester, the final product was homogenized on a 3-roll mill. The resulting grease is based on predominantly renewable raw materials.

Examples I and J:

Preparations of Example Formulations I and J correspond to the preparation of Example H using different amounts of calcium 12-hydroxy stearate, calcium acetate and calcium lignin sulfonate, and different compositions of ester base oils. The greases obtained in this way are based on predominantly renewable raw materials. Table 1: Cardan shaft fat formulations example A B reference invention Calcium complex description Calcium complex with 6% lignosulfonate with MoS2 1. thickener: 1.1 lignosulfonate: calcium ligninsulfonate 0.0 6.1 1.2 fatty acids / triglycerides: mixed fatty acid 4.8 2.9 Mixed triglyceride 4.8 2.8 1.3 Alkali Hydroxide: Ca (OH) 2 1.8 1.5 1.4 Complexing agent: Ca acetate 4.8 3.0 Ca-borate 0.1 0.2 2. Base oils: Mixed mineral oil (with v40 = 100 mm ² / s) 79.5 80.8 3. Additives: Antioxidant 1 0.6 0.5 Antioxidant 2 0.6 0.5 corrosion protection 0.5 0.2 Solid lubricant graphite 0.5 1.0 Solid lubricant MoS2 1.8 0.0 total 100 100 4. Characteristics method unit 4.1 General physical data Penetration forfeited DIN ISO 2137 0.1 mm 263 315 Penetration rolled 60 double acts DIN ISO 2137 0.1 mm 351 340 Copper corrosion 24 h / 100 ° C DIN 51811 Rank 1-100 1-100 Dropping point DIN ISO 2176 ° C 240 280 Oil separation 18 h / 40 ° C DIN 51817 % 0.4 2.1 Oil separation 7 d / 40 ° C DIN 51817 % 2 8.9 4.2 Water resistance static water resistance 3 h / 90 ° C DIN 51807-1 Rank 1-90 1-90 Washout loss at 80 ° C DIN 51807-2 Rank 1 1 4.3 Reduction of friction SRV at 80 ° C (40 Hz, 1.5 mm amplitude, 500 N load) ASTM D D5707-05 friction 0,107 0.097 course calm calm SRV at 150 ° C (40 Hz, 1.5 mm amplitude, 500 N load) ASTM D D5707-05 friction 0.097 0.085 course calm calm 4.4 Wear protection effect VKA welding load DIN 51350-4 N 3400 3800 N VKA calotte 1000 N / 1 min DIN 51350-5 mm 1.02 0.62 4.5 Compatibility with bellows materials 4.6.1 Chloroprene Inepsa 4012 168 h / 120 ° C - Shore A DIN 53505 -2 -1 - Volume change DIN 53521 % +3.5 -0.5 - change tensile strength DIN 53504 % -0.5 -1.2 - Change stretching DIN 53504 % -22.1 -19 4.6.2 NBR rubber SRE NBR 34 7 d / 100 ° C DIN 53538-3 - Shore A DIN 53505 -2 -3 - Volume change DIN 53521 % +3.4 +3.1 - change tensile strength DIN 53504 % -2.9 -5 - Change stretching DIN 53504 % -7.8 -4.5 4.6.3 TPE elastomers Hytrel 8332 336 h / 125 ° C - Shore D. DIN 53505 -3 -2 - Volume change DIN 53521 % +13.1 +6.2 - change tensile strength DIN 53504 % -32.9 +6.7 - Change stretching DIN 53504 % -27 +61 Arnitel EB 463 336 h / 125 ° C - Shore D. DIN 53505 -6 0 - Volume change DIN 53521 % +10.7 +10.2 - change tensile strength DIN 53504 % -15 -19.7 - Change stretching DIN 53504 % -10 +7.8 4.6.4 EPDM rubber Vamac Y76HR 336 h / 125 ° C - Shore A DIN 53505 +3 +5 - Volume change DIN 53521 % +6 +0.3 - change tensile strength DIN 53504 % -17.4 -1.8 - Change stretching DIN 53504 % -39 -35 5. Life test on the constant velocity universal joint shaft testing lifespan Million rollovers 13.6 11.2 Average steady temperature ° C 41.1 38.8

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited non-patent literature

• DIN 51807-1 (Issue: 1979-04) [0021]
• DIN 51807-2 (1990-03 edition) [0021]
• DIN ISO 2176 [0027]
• GE Fredheim, SM Braaten and BE Christensen, "Comparison of molecular weight and molecular weight distribution of softwood and hardwood lignosulfonate" published in the "Journal of Wood Chemistry and Technology", Vol. 23, No. 2, pp. 197-215, 2003 [ 0036]
• "Molecular weight determination of lignosulfonates by size exclusion chromatography and multi-angle laser scattering" of the same authors, published in Journal of Chromatography A, Volume 942, Issue 1-2, 4 January 2002, pages 191-199 (Mobile Phase: Phosphate). DMSO-SDS, stationary phase: Jordi-glucose DVB as described under 2.5) [0036]
• DIN ISO 2137 [0059]
• DIN ISO 2137 [0059]
• DIN 51811 [0059]
• DIN ISO 2176 [0059]
• DIN 51817 [0059]
• DIN 51817 [0059]
• DIN 51807-1 [0059]
• DIN 51807-2 [0059]
• ASTM D D5707-05 [0059]
• ASTM D D5707-05 [0059]
• DIN 51350-4 [0059]
• DIN 51350-5 [0059]
• DIN 53505 [0059]
• DIN 53521 [0059]
• DIN 53504 [0059]
• DIN 53504 [0059]
• DIN 53538-3 [0059]
• DIN 53505 [0059]
• DIN 53521 [0059]
• DIN 53504 [0059]
• DIN 53504 [0059]
• DIN 53505 [0059]
• DIN 53521 [0059]
• DIN 53504 [0059]
• DIN 53504 [0059]
• DIN 53505 [0059]
• DIN 53521 [0059]
• DIN 53504 [0059]
• DIN 53504 [0059]
• DIN 53505 [0059]
• DIN 53521 [0059]
• DIN 53504 [0059]
• DIN 53504 [0059]

Claims (21)

A process for producing lignosulfonate-containing greases comprising a) the step of bringing together at least: - a base oil A calcium soap, optionally in situ, having 10 or more carbon atoms, wherein when the calcium soaps are prepared in situ, at least calcium hydroxide is added, Calcium lignosulfonate having weight average molecular weights of greater than 10,000 g / mol, Heating to greater than 120 ° C for reaction and expulsion of low-boiling components to produce a base grease and b) a second step of cooling and adding base oil and optionally additives with mixing. A method according to claim 1, characterized in that in step a) calcium hydroxide is added in addition to optionally further alkaline earth metal hydroxides. A method according to claim 1, characterized in that the grease is made alkaline, in particular by the addition of calcium hydroxide in excess. A method according to claim 1, characterized in that the heating to temperatures of greater than 180 ° C, takes place. A method according to claim 1, characterized in that in addition to calcium hydroxide in step a) and lithium hydroxide, magnesium hydroxide and / or aluminum hydroxide or aluminum alkoxides and / or Aluminiumoxoalkoholate and / or lithium, magnesium and / or aluminum soaps of a saturated or unsaturated mono-carboxylic acid 10 to 32 carbon atoms, optionally substituted, are used. A method according to claim 1, characterized in that the grease independently contains: - 55 to 92 wt .-%, in particular 70 to 85 wt .-%, of the base oil, - 0 to 40 wt .-%, in particular 2 to 10 wt. -%, additives, - 3 to 40 wt .-%, in particular 5 to 20 wt .-%, soaps and - 0 to 20 wt .-%, in particular 0.5 to 10 wt .-%, complexing agent, and - if necessary Excess Ca (OH) ₂ , preferably 0.01 to 2 wt .-%, - 0.5 to 50, especially 2 to 15 wt .-%, and particularly preferably 4 to 8 wt .-% calcium lignosulfonate, if necessary ., in addition to other Erdalkaliligninsulfonaten, each based on the total composition of the lubricating grease. A method according to claim 1, characterized in that the base fat of step a) can be produced by using - 40 to 70 wt .-%, in particular 45 to 60 wt .-%, of the base oil, - 10 to 60 wt .-%, in particular 15 to 50 wt .-%, soaps and - 0 to 30 wt .-%, in particular 5 to 20 wt .-%, complexing agent, and - optionally excess Ca (OH) ₂ , preferably 0.02 to 4 wt. %, - 0.7 to 50, in particular 4 to 30 wt .-%. % Calcium lignosulfonate, optionally together with other alkaline earth metal sulfonates, in each case based on the composition of the base fat. A method according to claim 1 or 4, characterized in that the grease contains independently of each other 0.2-5 wt .-% graphite and / or no solid lubricant or less <1 wt .-% solid lubricant, in particular no MoS ₂ . A method according to claim 1, characterized in that the calcium soap is prepared in situ as a reaction product of calcium hydroxide, with a saturated or unsaturated mono-carboxylic acid having 10 to 32 carbon atoms, in particular having 16 to 20 carbon atoms, optionally substituted z. B. by hydroxy, as an ester or anhydride. A method according to claim 1, characterized in that the complexing agent as a reaction product of a calcium salt, in particular calcium hydroxide, with a saturated or unsaturated mono-carboxylic acid having 2 to 8, in particular 2 to 4, carbon atoms or a di-carboxylic acid with 2 to 16, in particular 2 to 12 carbon atoms, in each case optionally substituted, for. B. by hydroxy, as an ester or anhydride, while step a) is added. A method according to claim 1, characterized in that the complexing agent is a calcium salt of a carboxylic acid and in situ during step a) by adding a saturated or unsaturated mono-carboxylic acid having 2 to 8, in particular 2 to 4, carbon atoms or a di-carboxylic acid 2 to 16, in particular 2 to 12 carbon atoms, in each case optionally substituted, for. B. by hydroxy, is prepared as an ester or anhydride. Lubricating grease composition comprising - 55 to 92 wt .-%, in particular 70 to 85 wt .-%, of the base oil, - 0 to 40 wt .-%, in particular 2 to 10 wt .-%, additives, - 3 to 40 wt .-%, in particular 5 to 20 wt .-%, calcium soaps having 10 and more carbon atoms, - 0 to 20 wt .-%, in particular 0.5 to 10 wt .-%, complexing agent, and - optionally excess Ca (OH ) ₂ , preferably 0.01 to 2 wt .-%, - 0.5 to 50, especially 2 to 15 wt .-%, and most preferably 2 to 8 wt .-% calcium lignosulfonate, optionally in addition to other Erdalkaliligninsulfonaten, in each case based on the total composition of the grease. A composition according to claim 12, characterized in that the composition has a cone penetration value (walk penetration) of 265 to 385 mm / 10 (at 25 ° C), preferably 285 to 355 mm / 10, determined according to ISO 2137. Composition according to at least one of Claims 12 or 13, characterized in that the base oil has a kinematic viscosity of 20 to 2500 mm ² / s, preferably 40 to 500 mm ² / s, at 40 ° C. Composition according to at least one of Claims 12 to 14, characterized in that the complexing agent consists of: An alkali metal salt, preferably lithium salt, alkaline earth metal, preferably calcium salts, or aluminum salt of a saturated or unsaturated mono-carboxylic acid having 2 to 8, in particular 2 to 4, carbon atoms or a di-carboxylic acid having 2 to 16, in particular 2 to 12 carbon atoms, each optionally substituted. Composition according to at least one of claims 12 to 15, characterized in that the additive comprises one or more members selected from the following group: Antioxidants such as amine compounds, phenolic compounds, sulfur dioxide antioxidants, zinc dithiocarbamate or zinc dithiophosphate; High pressure additives such as organic chlorine compounds, sulfur, phosphorus or calcium borate, zinc dithiophosphate, organic bismuth compounds; C2 to C6 polyols, fatty acids, fatty acid esters or animal or vegetable oils; Anticorrosion agents such as petroleum sulfonate, dinonylnaphthalenesulfonate or sorbitan esters; Metal deactivators such as benzotriazole or sodium nitrite; - viscosity improvers such as polymethacrylate, polyisobutylene, oligo-dec-1-ene, and polystyrenes; Antiwear additives such as molybdenum di-alkyl dithiocarbamates or molybdenum sulfide di-alkyl dithiocarbamates, aromatic amines; - Friction modifier such as functional polymers such. Oleylamides, polyether- and amide-based organic compounds or molybdenum dithiocarbamate, and - Solid lubricants such. As polymer powder such as polyamides, polyimides or PTFE, graphite, metal oxides, boron nitride, metal sulfides such. As molybdenum disulfide, tungsten disulfide or mixed sulfides based on tungsten, molybdenum, bismuth, tin and zinc, inorganic salts of alkali and alkaline earth metals, such as. As calcium carbonate, sodium and calcium phosphates. Composition according to at least one of claims 12 to 16, characterized in that the grease is water resistant and that a) according to the test according to DIN 51807-1, the evaluation level 1-90 and / or b) according to the test according to DIN 51807-2 of the evaluation level 1-80. A composition according to at least one of claims 12 to 17, characterized in that the calcium lignosulfonate has an average molecular weight (Mw, weight average) of greater than 10,000, in particular greater than 12,000 or even greater than 15,000 g / mol, which independently of this 2 to 12 wt. -% in particular 4 to 10 wt .-%, sulfur (calculated as elemental sulfur) and / or further independently 5 to 15 wt .-%, in particular 8 to 15 wt .-% calcium. Use of the composition according to at least one of claims 12 to 18 for the lubrication of at least one constant-velocity joint, in particular as part of homokinetic propeller shafts, and a rolling and sliding bearing. A composition according to at least one of claims 12 to 19, characterized in that lubricating grease contains a base oil based on renewable raw materials and / or is constructed to a proportion of greater than 95% based on renewable raw materials. Method according to at least one of claims 1 to 11, characterized in that the calcium lignosulfonate is dehydrated before the addition to values of less than 0.5 wt .-% water, for. B. by heating in the base oil to about 95 ° C, especially about 100 ° C to z. B. 120 ° C.