Lubricant composition and lubricant coating containing particulate plastics

Abstract

The subject matter of the invention is a lubricant composition for applying a lubricant coating to a component, whereby the lubricant coating serves as protection against wear and for the targeted adjustment of friction coefficients for different material pairings. The lubricant composition comprises at least one binder, particulate plastics, waxes, and an organic solvent, wherein the lubricant composition is in particular fluorine-free. The invention also relates to a lubricant coating and a component provided with the lubricant coating.

Description

[0001] Lubricant composition and lubricant coating containing particulate plastics

[0002] The present invention relates to a lubricant composition for applying a lubricant coating to a component, whereby the lubricant coating serves as protection against wear and / or for the targeted adjustment of friction coefficients for different material pairings. The lubricant composition comprises at least one binder, particulate plastics, waxes, and an organic solvent, wherein the lubricant composition is free of PTFE, preferably comprises no per- and polyfluorinated alkyl substances and most preferably is fluorine-free, which also means free of fluorine-containing compounds. The invention also relates to a lubricant coating that forms a dry film lubricant coating after curing and a component having a dry film lubricant coating applied.

[0003] Introduction and state of the art

[0004] Lubricant compositions-are often dispersions of selected solid lubricants in a liquid medium comprising a binder and an organic or aqueous solvent for the binder. In addition to the binder(s), a wide variety of substances are used as additives in the lubricant compositions: these are predominantly solid lubricants such as molybdenum disulfide, graphite, layered silicates, and polytetrafluoroethylene.

[0005] The lubricant compositions are used to coat components, forming a lubricant coating on the component. After drying and curing, the lubricant compositions form a dry film lubricant coating that is often only a few micrometres thick and adheres firmly to the substrate. This lubricant coating acts as a friction- and wear-reducing separating and lubricating layer between the friction partners in contact. The term lubricant coating applies to a lubricant coating before and after curing, while the term dry film lubricant coating applies only to a lubricant coating after curing. The lubricant compositions form a lubricant coating, and after curing and drying, a dry film lubricant coating, meaning that the binder is hardened or cured I cross-linked and the solvent is reduced I has disappeared.

[0006] The coating can be applied immediately before assembly. However, the components are usually coated first and then stored, so that they are ready for assembly and permanently provided with lubrication in the form of the lubricant coating.Polytetrafluoroethylene (PTFE) is widely used in industry due to its unique perfluorinated structure and resulting properties, including good non-stick properties and thermal and chemical resistance. In addition, PTFE also has a very low coefficient of friction and good anti-wear properties, which is why PTFE is widely used as a solid lubricant in lubricant coatings.

[0007] The use of per- and polyfluorinated alkyl substances (PFAS) is now considered problematic because these compounds are highly persistent, as they do not degrade in nature. Some PFAS compounds are believed to have liver-damaging, reproductive-toxic, and carcinogenic properties. Due to their poor degradability, PFAS tend to accumulate as "forever chemicals" in the environment and in human and animal organisms. At the beginning of 2023, several Ell member states, including Germany, submitted a proposal to restrict or drastically reduce PFAS emissions. There is therefore a general desire to replace compositions containing PFAS with those that have the same or even better properties but do not contain PFAS, or at least to drastically reduce the PFAS content.

[0008] Japanese patent applications JP 2008037905 A, JP 2006206683A, and JP 1997013070 A disclose aqueous coating formulations based on various aliphatic waxes, e.g., paraffins, micro waxes, polyolefin waxes or ester waxes and binders, e.g. based on copolymers, urethanes or epoxy resins, and can be used as coatings for screws, among other applications.

[0009] EP 3601445 B1 describes the use of polymers such as polyamideimides, polyeth-eretherketones, polyetherketones, or polyethersulfones as dissolved resins and as curing binder components in a graphene-containing solvent-based lubricant composition in combination with organic and inorganic solid lubricants such as waxes, PTFE, metal sulfides, silicates, and others. The preferred lubricant combinations contain PTFE and form after curing a dry film lubricant coating.

[0010] WO 2015091802 A1 (= EP 3083750 B1) teaches an antifriction coating composition which comprises: a resin binder, a polyamide thickener, a solvent and PTFE as a solid lubricant, wherein the resin binder comprises a mixture of phenolic resin, epoxy resin and optionally a silicone resin.Object of the invention

[0011] In the prior art there are already lubricant coatings proposed that are free of fluo-rine-containing polymers, waxes, or additives. Lubricant coatings require that the tribological properties be adjusted to the material pairing or that lubricant coatings be created that are suitable for a variety of material pairings. The films of the lubricant coatings must also have other application-dependent properties, such as wear resistance and / or corrosion protection properties. Due to their chemical properties, PFAS-containing lubricants can often be used as all-rounders, combining good sliding and non-stick properties with water- and dirt-repellency. Replacing these fluorine-containing raw materials requires individually tailored formulations with specific properties such as well adjusted friction coefficients or special wear resistance or non-stick properties.

[0012] The purpose of the present invention is to provide lubricant compositions and lubricant coatings without fluorinated additives such as PTFE. The resulting cured films in the form of lubricant coatings should be usable on different substrates such as metallic components, elastomers, or plastics in order to minimize friction and wear. The resulting property profile of the lubricant coating according to the invention should be at least equivalent to or even improved compared to formulations containing fluorine.

[0013] Summary of the invention

[0014] The task is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims or are described below.

[0015] The PTFE-free lubricant compositions of the present invention comprise the following components:

[0016] (a) binders selected from one or more members of the group:

[0017] polyurethanes, melamine resins, epoxy resins cured by reaction of epoxy groups with one or more of aliphatic primary or secondary amines, aromatic primary or secondary amines, the amines each having at least two amine groups, and amides having at least two amide groups, and polyamideimide resins;(b) particulate plastics selected from one or more members of the group: poly- etheretherketones, polyphenylene sulfides, and polymethylene ureas;

[0018] (c) waxes selected from one or more members of the group:

[0019] paraffin waxes, modified paraffin waxes, Fischer-Tropsch waxes, modified Fischer-Tropsch waxes, polyolefin waxes, modified polyolefin waxes, amide waxes, carnauba waxes, and rice bran waxes,

[0020] in particular polyolefin waxes, modified polyolefin waxes, carnauba waxes and rice bran waxes;

[0021] wherein (b) and (c) are in a weight ratio of 1 :3 to 3:1 , preferably

[0022] 2:1 to 1:2.5, particularly preferably 1.5:1 to 1:2, each based on dry content;

[0023] (d) at least 40 wt.%, preferably at least 55 wt.%, of one or more organic solvents selected from the group

[0024] organic solvents having hydroxy, keto, ester, and / or ether groups, aromatic hydrocarbons, aliphatic hydrocarbons, and lactams, amines, or amides.

[0025] The lubricant compositions are dispersions and are in a liquid state, i.e. , the lubricant compositions flow and spread under their own weight.

[0026] The invention also relates to lubricant coatings and components with the lubricant coatings, which are produced by curing the lubricant composition, e.g. by evaporation of the solvent (physical curing) and / or cross-linking of the binder (chemical curing), thereby forming dry film lubricant coatings and components with dry film lubricant coatings. As the lubricant coatings are applied, the solvent evaporates from the lubricant composition.

[0027] Surprisingly, it was found that lubricant compositions comprise at least the following components as base components, the base components consisting of (a), (b), and (c):

[0028] (a) one or more binders,

[0029] (b) one or more particulate plastics,

[0030] (c) one or more waxes;

[0031] as well as

[0032] (d) one or more organic solvents,as defined in more detail above, result in lubricant coatings that exhibit both friction and wear characteristics that provide tribological properties comparable to or even better than those of a PTFE-containing lubricant coating. Optional components include solid lubricants (e) and additives (f).

[0033] At least the binder (a), the plastic particles (b) and a wax (c), dispersed as a solid with respect to (b) and (c) and, for example, dissolved with respect to (a) in a solvent (d), form the lubricant composition, wherein the lubricant composition may contain further components such as solid lubricants (e) and various additives (f) in addition to the base components. The solvent (d) is not part of the base components.

[0034] The additives can be further subdivided into

[0035] (f1) emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives (thickeners), defoamers, and UV additives or colorants.

[0036] and separately from this

[0037] (f2) fillers.

[0038] The invention also relates to lubricant coatings on a material or component. For this purpose, the lubricant composition is applied thinly to an object, for example by means of spray or dip coating. As the lubricant coating is applied, the solvent evaporates from the lubricant composition, resulting in a solid, adherent, and usually dry film. The result is a lubricant coating that is a few micrometers thick, adheres firmly to the component, is mechanically stable, and after curing becomes a dry film lubricant coating.

[0039] If desired, the resulting layer can be further cross-linked by supplying thermal energy, for example. The lubricant coating acts as a friction- and wear-reducing separating and lubricating layer between rubbing partners in contact.

[0040] Detailed description of the invention

[0041] Binders:The binders (a) bind the individual formulation components after solidification to form a dry film lubricant coating that adheres well to the substrate and is wear-resistant. The binder acts as a matrix, ensuring the formation of a firmly adhering film.

[0042] The binder is selected from one or more members of the group: polyurethane resins, melamine resins, epoxy resins, polyamideimide resins, in particular polyurethanes, melamine resins, epoxy resins, and polyamideimide resins. The epoxy resins are those that are cured or hardened by reaction of epoxy groups with one or more of aliphatic primary or secondary amines, aromatic primary or secondary amines, each having at least two amine groups. The aminic hardeners can be further modified, for example by adduct formation (e.g. from bisphenol A resins and base amines such as trimethylhexamethylenediamines or triethylenetetramine) or by formation of Mannich bases (e.g. from reaction of phenolic compounds and aldehydes with base amines). Further modifications of the amines can be achieved by amide formation with fatty acids, whereby the resulting hardeners contain at least one amide group. Mixtures of different amine and / or amide hardeners can also be used as hardener components.

[0043] All aminic hardener compositions can also contain other components such as accelerators (e.g. salicylates, imidazoles, phenols), low molecular weight aliphatic or aromatic alcohols (e.g. benzyl alcohol), for example for viscosity adjustment, wetting, reactivity control or other components such as carbonic and fatty acids or solvents.

[0044] The individual binders can be used either in pure form as solid resins or as liquids or solutions in an organic solvent. If they are used as solid resins, they are dissolved in the solvent.

[0045] Polyurethane resins are, for example, those obtainable from the reaction of hydroxyl group-containing prepolymers with polyisocyanates. The hydroxyl group-containing prepolymers can be, for example, epoxy group-containing prepolymers. One example is bisphenol-based epoxy resins, such as those produced by reacting epichlorohydrin with bisphenol A. Other examples of hydroxyl group-containing prepolymers are polyethers, polyesters, polycarbonates, polyacrylates, and novo-laks.These are cross-linked with free or blocked aliphatic or aromatic polyisocyanates. Aliphatic starting compounds for the polyisocyanates are preferably hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) or 1 ,4. cyclohexyl diisocyanate (CHDI), while toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) or polymeric diphenylmethane diisocyanate (PMDI) can preferably be used as aromatic components. Epoxy resins are reaction resins containing epoxy groups, which, after mixing with a hardener, react to form a thermosetting macromolecular polyether. Monomers, oligomers, or prepolymers containing epoxy groups can be used as epoxy group-containing components, which are produced, for example, by reacting epichlorohydrin with hydroxy-functionalized compounds. The hydroxy-functionalized compounds can be aliphatic diols and polyols or aliphatic or aromatic dicarboxylic acids. However, phenolic compounds such as bisphenol A or novolaks are also frequently used. The cross-linking of the components containing epoxy groups occurs through reactions of the epoxy groups, preferably with aliphatic and / or aromatic primary and / or secondary polyamines or polyamides being hardeners. If necessary, accelerators or catalysts can be added to shorten the reaction times or lower the curing temperatures. The polyamines or polyamides have at least two amine or amide groups.

[0046] Polyamideimide resins can be produced by reacting aliphatic or aromatic anhydrides with aliphatic or aromatic amines. However, an alternative method is to react aliphatic and / or aromatic anhydrides with aliphatic and / or aromatic isocyanates. Due to their thermal stability, aromatic building blocks are preferred for the industrial production of polyamideimides. For this purpose, trimellitic acid derivatives, preferably trimellitic anhydride (TMA), are usually reacted with, for example, 4,4'-diaminodiphenylmethane (MDA) or with, for example, 4,4'-methylenediphenyl diisocyanate (MDI).

[0047] Melamine resins are aminoplasts based on melamine and formaldehyde. The resulting hydroxymethylmelamines can be etherified, which, through reaction with alcohols, preferably methanol, ethanol, propanol, isopropanol, butanol, or isobutanol, as well as mixtures thereof, results in corresponding ethers or mixed ethers. Melamine resins can be further modified via etherification reactions. For this purpose, aminofunctionalized, hydroxyfunctionalized, or carboxylic acid-functionalized compounds can be used, for example.If polyfunctional components are used, additional cross-linking reactions can take place between the individual melamine resin molecules. If necessary, catalysts (e.g., free or amine-neutralized acids) can be added to shorten reaction times or lower curing temperatures.

[0048] Particulate plastics:

[0049] Plastics are polymeric materials in which the macromolecules have a degree of polymerization ranging from several thousand to over a million. The monomers can form both homopolymers (same monomers) and copolymers (different monomers). Plastics can be classified as follows:

[0050] - Thermoplastics consist of non-crosslinked, linear polymers that often have a semi-crystalline structure. Examples include polyetheretherketone (PEEK) or polyphenylene sulfide. They have a glass transition temperature and are meltable.

[0051] - Thermosets exhibit cross-linking of the polymers. Examples of this are polymethylene ureas. After curing, such materials can no longer be deformed by heating or other measures.

[0052] Compared to the waxes (c) that are also used, particulate plastics (b) generally have higher melting points (thermoplastics) or do not melt in the case of thermosets, or melt only with decomposition, but in any case above the melting point of waxes (c).

[0053] On the other hand, particulate plastics (b) often have higher hardnesses than waxes. The hardness of many plastics can be measured using the SHORE hardness test method and is usually in the SHORE D hardness range.

[0054] Unlike waxes, plastics are therefore not malleable at room temperature. Waxes are not in this hardness range and are softer. Particulate plastics are therefore more wear-resistant. Plastics are used in particulate form for use in coatings, with particle sizes preferably below 40 pm (D90). The particulate plastics can be poly-etheretherketone (PEEK), polyphenylene sulfide (PPS), polysilsesquioxanes, polymethylene urea (PMU), and mixtures thereof. The plastic particles can be provided either in powder form or as a dispersion in a solvent.The particulate plastics are dispersed in the lubricant composition as particulate solids, i.e. , they are not dissolved by the solvent (d).

[0055] Waxes:

[0056] Another component of the base components are waxes, which can be defined as follows according to the definition of the German Society for Fat Science: Kneadability at 20°C, solid to brittle hard; a coarse to fine crystalline structure; translucent to opaque in color, but not glass-like; melt above 40°C without decomposition; slightly liquid (low viscosity) just above the melting point. Compared to many harder and fluorine-free plastics, waxes have a significantly improved lubricating effect.

[0057] These can be individually or in combination: paraffin waxes, modified paraffin waxes, Fischer-Tropsch waxes, modified Fischer-Tropsch waxes, polyolefin waxes, modified polyolefin waxes, carnauba waxes, and rice bran waxes, in particular polyolefin waxes, modified polyolefin waxes, carnauba wax, and rice bran wax.

[0058] The waxes are, for example,

[0059] - paraffin waxes (mineral oil-based) and modified paraffin waxes, which can be characterized as a combination of saturated hydrocarbons consisting predominantly of unbranched carbon chains.

[0060] - Fischer-Tropsch waxes and modified Fischer-Tropsch waxes (synthetic waxes produced using Fischer-Tropsch synthesis), consisting largely of unbranched hydrocarbon chains);

[0061] - Polyolefin waxes and modified polyolefin waxes, which are produced by polymerization of ethylene (polyethylene wax), propylene (polypropylene wax) and other monomers.

[0062] The waxes mentioned can be modified in various ways, including by incorporating polar and non-polar copolymers, grafting, e.g. with maleic anhydride, carboxylation, oxidation, and incorporation of inorganic functionalities such as silanes.For use in coatings, the waxes are preferably used in particulate and microscale form, with particle sizes below 40 pm (D90), preferably less than 25 pm (D90). The waxes are dispersed in the lubricant composition as particulate solids, i.e. , they are not dissolved by the solvent (d).

[0063] Organic solvents (also called “solvents” hereinafter in short)

[0064] The solvents used are organic solvents. These have hydroxy, keto, ester, and / or ether groups; suitable examples are alcohols, ketones, lactones, glycols, esters, in particular esters with ether groups, and also aromatic (including substituted aromatics such as alkylaromatics) or aliphatic hydrocarbons and mixtures thereof. Ni-trogen-containing solvents such as lactams (e.g., N-ethyl-2-pyrrolidone) or amides are also suitable.

[0065] Solvents from the group of ketones, esters, ethers, aromatic or aliphatic solvents, as well as lactams (e.g., N-ethyl-2-pyrrolidone) or amides are preferred. Solvents from the group of esters and ethers are particularly preferred. If different solvents are used, they preferably mix in a single phase.

[0066] According to one embodiment, the solvent preferably has a boiling point below 215°C or, according to another embodiment, below 180°C.

[0067] Suitable solvents in relation to the above-mentioned groups are:

[0068] Alcohols: ethanol, isopropanol, butanol

[0069] Lactones: gamma-valerolactone

[0070] Glycols: 2-butoxyethanol

[0071] Esters: 1 -methoxy-2-propyl acetate, butyl acetate

[0072] Lactams: N-ethyl-2-pyrrolidone

[0073] Amides: 3-methoxy-N,N-dimethylpropionamide

[0074] The lubricant composition contains less than 2 wt.% of water, in particular, less than 0.5 wt.% water. The water may originate in particular from residual moisture in solvents or possibly also from residual moisture in solids such as waxes, plastics, or additives.Solid lubricants

[0075] Optionally, one or more solid lubricants such as molybdenum disulfide and / or graphite and / or layered silicates may also be included.

[0076] Additives

[0077] Corrosion inhibitors protect metallic substrates from corrosion in various ways. Examples of corrosion inhibitors are corrosion-inhibiting pigments based on phosphates such as zinc phosphates, corrosion inhibitors that coat the metal surface such as sulfonates, zinc 5-nitroisophthalates or sebacates.

[0078] In the lubricant compositions according to the invention, several additives are often used simultaneously.

[0079] Fillers are understood to be additives that are insoluble in the solvent and can be added, for example, to mechanically reinforce the polymer matrix in coatings. Microscale ceramic hard materials such as corundum, silicon carbide, or silicon dioxide, as well as anisotropic microfibers such as glass or carbon fibers, are often used for this purpose, with anisotropic fibers in particular leading to high strength and stiffness of the matrix materials. Metallic fillers can also be used.

[0080] Emulsifiers are used to improve the dispersion of plastic and wax particles in the solvent in order to obtain homogeneous and stable dispersions.

[0081] Anti-sedimentation additives either increase viscosity as rheology additives or alter the surface of the solids to be stabilized; some combine both properties. To increase viscosity, additives with shear-thinning, thixotropic, or pseudoplastic flow behavior are often used, which liquefy easily under mechanical stress such as stirring. They protect against sedimentation at rest and at the same time enable the necessary lower viscosity ranges for coating (spraying, dip centrifuge, etc.). For example, layered silicates such as bentonites or laponites, urea derivatives, acrylates, polyurethanes, or polyamides can be used. Anti-sedimentation additives, which act via chemical surface modification, are anchored to the solid to be stabilized (adsorptive or by chemical bonding) and have a steric, electrostatic, or elec-trosteric stabilizing effect.For example, silanes can be used to stabilize oxidic solids with hydroxide groups, which are anchored to the solids by a condensation reaction. The silanol group is used as an anchor group, while the organic residue determines the stabilizing properties. There are also chemical surface modifiers that additionally build up a network, thereby separating the particles from each other.

[0082] Wetting and leveling additives improve the wetting of the coating medium on the substrate and enable the formation of a homogeneous coating. Their mode of action is based on reducing the surface tension of the coating medium. For example, polysiloxanes, polyacrylates, silicone-containing or silicone-free surfactants such as polyether-modified siloxanes or alcohol alkoxylates can be used.

[0083] Defoamers help trapped air bubbles escape from the coating agent by destabilizing the foam lamellae. For example, polysiloxanes, paraffin-based mineral oils, or polymer defoamers (e.g., polyolefins) can be used in combination with hydrophobic particles.

[0084] UV additives can be used to make the applied coating visible using UV light in order to check the homogeneity of the applied coating. UV-active fluorescent dyes, for example, can be used as UV additives. Instead of UV additives, various color pigments can also be used for coloring. Metal oxides or carbon black can be used for this purpose.

[0085] Preservatives are used primarily in aqueous formulations to preserve the formulation and protect it from contamination by microorganisms and mold. For example, formaldehyde releasers such as EDDM (ethylenedioxydimethanol) or TMAD (tetra-hydro-1 ,3,4,6-tetrakies-(hydroxymethyl)-imidazo-[4,5-d]-imidazole-2,5-(1 H,3H)-di-one), isothiazolones such as MIT (methylisothiazolone), pyrithione, or bromor-ganyls can be used.

[0086] The plastic particles (b) and the waxes (c) as well as other components such as solid lubricants (e) and some of the additives (f) are present as solids dispersed in the lubricant composition. The binders and other additives may be dissolved or emulsified in the solvents. Some of the raw materials used may contain other ingredients such as residual monomers or other solvents, which then become part of the lubricant composition in solid or liquid form.The lubricant composition is a solid dispersion, wherein at least the solvent forms the liquid / continuous phase and the solid / disperse phase is the heterogeneous phase, wherein the particle size of the plastic particles (b), waxes (c) and the optional solid lubricants (e) as well as additives (f), measured as particle diameter D90, is preferably less than 40 pm (D90) in each case, particularly preferably less than 25 pm (D90) or even less than 10 pm (D90).

[0087]

[0088] suitable combinations of the

[0089]

[0090] Particularly suitable lubricant compositions or lubricant coatings obtainable therefrom with regard to the selection of components (a), (b), (c), and (d) are summarized in Table 1.

[0091] Manufacturing

[0092]

[0093] In the first step, parts of the solvent are mixed with the binder, the particulate plastic, the wax and, if necessary, the solid lubricant and at least one of the additives. This mixing takes place in a mixing container with the aid of a stirring unit (dissolver). In the second step, the incorporated solids are dispersed by applying shear forces in a grinding unit. This reduces the size of the solids and distributes them homogeneously in the formulation. In a third step, the mixture is completed by incorporating the missing additives or residual amounts of solvent into the formulation via a simple stirring process. The formulation can be filtered to remove any remaining coarse particles.

[0094]

[0095] of com

[0096] The components comprising the lubricant composition as a dry film lubricant coating can be made of metal, ceramic, and / or plastic, including elastomers or composite plastics. The components are in frictional contact with another component where the lubricant coating is applied. The lubricant coating can be applied to only one component or to both components.A wide range of materials (metals, plastics, elastomers, ceramics, glass, etc.) are suitable for dry lubrication with lubricant coatings. When metals are used as surfaces, components with a wide variety of geometries, such as screws, connecting and fastening parts, are used primarily in the automotive industry and mechanical engineering. These can be, for example, bolts, hinges, springs, lock parts, shafts, bearing elements, spindles, pistons, or a variety of different screw and nut types. The possible applications of sliding dry film lubricant coatings for plastics and elastomers are just as diverse as those for metal coatings. In the latter case, sealing materials such as O-rings are often coated. Plastic parts are also frequently coated with lubricant coatings to reduce wear. These can be, for example, plastic guides, hinges, or plug connections in the furniture industry, or switching mechanisms in the electronics sector.

[0097] Lubricant coatings are also frequently used to reduce noise on plastic components or on various material combinations made of plastics, elastomers, and imitation leather, especially in automotive interiors. In addition to a wide variety of component tests (e.g., friction coefficient tests on screws and nuts), testing technology can also involve special components for standardized test procedures, such as test plates made of metals, plastic sheet materials, various bolts, or cylinders, which can be coated with a lubricant coating.

[0098] Surface pretreatment

[0099] The first step in the coating process is the surface preparation of the components. This can play a special role for the lubricant coating in order to ensure good adhesion and the associated long service life on the component. Pre-treatment of the workpiece surface includes the thorough removal of all types of grease residues as well as dust, dirt, rust, and scale. In order to achieve optimum performance of the inventive lubricant coatings on the respective materials and components, a suitable surface pretreatment is integrated into the coating process in each case. This generally ensures sufficient adhesion of the coatings to their substrates, which is essential for long film lifetimes. The respective pretreatment method depends on the corresponding materials. For the coating of metallic substrates, primarily steel, the mechanical surface pretreatments typical for paint coatings, such as grinding, polishing, blasting, and brushing, can be used.In addition, chemical pretreatment methods such as pickling, anodizing, electroplating, galvanizing, chromating, chemical nickel plating, and, in particular, phosphating are also used in industrial coating processes.

[0100] Phosphating in particular is the preferred method for most applications of lubricant coatings. This significantly improves the adhesion of the lubricant coating to the metal surface compared to a degreased or blasted surface. In many applications, this leads to a considerable increase in the service life of the lubricant coating. In addition, phosphating significantly increases the corrosion protection effect of the lubricant coating. Zinc or manganese phosphating is usually used.

[0101] Plastics and elastomer materials can be pretreated with oxygen plasma treatment, whereby chemical activation of the substrate surface is obtained and the reactivity created towards the binders allows the lubricant coating to be anchored by chemical reaction.

[0102] Application process

[0103] The geometry of the component and the application-related properties of the selected lubricant composition are the main factors determining the choice of a suitable application method. The lubricant coating can be applied using the methods commonly used in coating technology, such as spraying, dip spinning, tumbling, and dip centrifuging.

[0104] Lubricant coating

[0105] The lubricant coatings on the components enable both defined friction behavior and special wear resistance to be achieved on a wide variety of materials (metals, preferably steel, plastics, and elastomers). Although low friction coefficients can be achieved with the aid of lubricants (e.g., waxes) in a binder matrix, the wear performance is then insufficient in many applications and on different surfaces and materials. The addition of plastic particles (b) significantly improves wear performance, surprisingly achieving a comparable property profile to lubricant coatings containing fluoropolymers (especially PTFE).Air-drying lubricant compositions are dried at room temperature prior to tribological stress, while heat-curing lubricant compositions or lubricant coatings are cured after application, whereby thermal cross-linking of the binders takes place. Depending on the chemistry of the lubricant composition used, the usual curing temperatures range from approximately 80 to 250 °C

[0106] The invention is further described by the following figures. They depict:

[0107] Fig. 1 A friction coefficient diagram as a measurement record from the SRV test for recording the friction coefficients vs. time and determining the average friction coefficient COF.

[0108] Fig. 2 Sketch illustrating the average wear cross-section A of a wear track using 3D microscopy.

[0109] Fig. 3 Comparison of the average coefficients of friction COF of coatings in examples 1 to 4.

[0110] Fig. 4 Comparison of the average wear cross-sections A of coatings from examples 1 to 4.

[0111] Test methods

[0112] Unless otherwise stated in the description, the parameters specified have been determined as follows:

[0113] Particle sizes can be determined using laser diffraction methods in accordance with ISO 13320. Depending on the nature of the solids to be examined, the measurements can be carried out either dry or in dispersion with water or organic solvents (e.g., isopropanol), and ultrasound can be applied for deagglomeration. Preferably, the particle sizes are evaluated from the volume distributions obtained from the measurements.

[0114] The melting behavior and, in particular, the melting point of plastics and waxes can be examined, for example, using dynamic differential calorimetry (DSC) in accordance with DIN EN ISO 11357-3.

[0115] The hardness of waxes can be determined using penetrometric methods, e.g., according toASTM D 1321.The term "parts by weight" (PPW) is used when a relative definition with a self-selected reference value is used, where the reference value then stands for 100 PBW.

[0116] Specifications in weight percent (wt.%) refer to the selected medium as a whole, e.g., the lubricant composition or the lubricant coating .

[0117] Dry content is understood to mean all components of a composition after the liquid components, such as solvents, residual moisture, etc., have been removed. The dry content can be determined by evaporating the liquid components until the weight remains constant, preferably at a temperature of 200°C (in accordance with DIN EN ISO 3251 - 2019-09). Unless otherwise specified, the proportions refer to the substance as such without any residual monomers, residual moisture, solvents, etc.

[0118] The layer thickness of the lubricant coating is measured in accordance with DIN EN ISO 2178.

[0119] Test examples (experimental part)

[0120] The present invention is further explained with reference to the following experimental examples. In all cases, the binder (based on polyurethane) and the additives (consisting of a rheology additive, a leveling additive, and a defoaming additive) were kept the same in the formulations described. However, the particulate solids were varied in each case, consisting either of PTFE only (see Example 1) or of plastic and / or wax (see Examples 2 to 6).

[0121]

[0122] of the lubricant

[0123] The lubricant compositions were produced on a laboratory scale, whereby the respective individual components were mixed together in stainless steel vessels while stirring with a commercially available mixing unit (laboratory dissolver with toothed disc). The finely dispersed micronized solids that had been stirred in beforehand were ground using a commercially available ball mill.Example 1 (containing PTFE, comparison):

[0124] 64.6 wt.% Methoxypropyl acetate

[0125] 19.4 wt.% Polyurethane from an epoxy-based polyol prepolymer and a polyisocyanate

[0126] 14.9 wt.% PTFE-based solid lubricant (micronized)

[0127] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0128] 100.0 wt.%

[0129] The solvent methoxypropyl acetate was placed in a stainless steel container and solutions of the polyol prepolymer (40% in methoxypropyl acetate) and the polyisocyanate (70% in a solvent mixture of 1 -methoxy-2-propanol and ethyl acetate) were added one after the other and stirred homogeneously using a dissolver. The PTFE-based solid lubricant was then dispersed using a dissolver. The resulting dispersion was homogenized using a bead mill. Finally, the additive package (comprising rheology additive, leveling additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver.

[0130] Example 2 (with plastic, without wax, comparison):

[0131] 64.6 wt.% Methoxypropyl acetate

[0132] 19.4 wt.% Polyurethane from an epoxy-based polyol prepolymer and a polyisocyanate

[0133] 14.9 wt.% Polymethylene urea (micronized)

[0134] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0135] 100.0 wt.%

[0136] The solvent methoxypropyl acetate was placed in a stirring vessel and solutions of the polyol prepolymer (40% in methoxypropyl acetate) and the polyisocyanate (70% in a solvent mixture of 1 -methoxy-2-propanol and ethyl acetate) were added one after the other and stirred homogeneously using a dissolver.The polymethylene urea was then dispersed using a dissolver. The resulting dispersion was homogenized using a bead mill. Finally, the additive package (comprising rheology additive, leveling additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver.

[0137]

[0138] 3 wax, without

[0139] 64.6 wt.% Methoxypropyl acetate

[0140] 19.4 wt.% Polyurethane from an epoxy-based polyol prepolymer and a polyisocyanate

[0141] 14.9 wt.% Polyolefin solid wax (micronized)

[0142] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0143] 100.0 wt.%

[0144] The solvent methoxypropyl acetate was placed in a stirring vessel and solutions of the polyol prepolymer (40% in methoxypropyl acetate) and the polyisocyanate (70% in a solvent mixture of 1 -methoxy-2-propanol and ethyl acetate) were added one after the other and stirred homogeneously using a dissolver. The polyolefin solid wax was then dispersed using a dissolver. The resulting dispersion was homogenized using a bead mill. Finally, the additive package (comprising rheology additive, leveling additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver.

[0145] Example 4 (with plastic and wax, according to the invention):

[0146] 64.5 wt.% Methoxypropyl acetate

[0147] 19.4 wt.% Polyurethane from an epoxy-based polyol prepolymer and a polyisocyanate

[0148] 5.0 wt.% Polymethylene urea (micronized)

[0149] 10.0 wt.% Polyolefin solid wax (micronized)

[0150] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0151] 100.0 wt.%

[0152] The solvent methoxypropyl acetate was placed in a stirring vessel and solutions of the polyol prepolymer (40% in methoxypropyl acetate) and the polyisocyanate (70% in a solvent mixture of 1 -methoxy-2-propanol and ethyl acetate) were added one after the other and stirred homogeneously using a dissolver.The polyolefin solid wax and the polymethylene urea were then dispersed one after the other using a dissolver.

[0153] The resulting dispersion was then homogenized using a bead mill. Finally, the additive package (comprising rheology additive, leveling additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver.

[0154] Example 5 (with plastic and wax, according to the invention):

[0155] 64.5 wt.% Methoxypropyl acetate

[0156] 19.4 wt.% Bisphenol A based epoxy resin and a polyamine hardener composition (based on an amine adduct of a Bisphenol A resin with an aliphatic polyamine)

[0157] 5.0 wt.% Polyphenylene sulfide (PPS)

[0158] 10.0 wt.% Polyolefin solid wax (micronized)

[0159] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0160] 100.0 wt.%

[0161] The solvent methoxypropyl acetate was placed in a stirring vessel and the epoxy resin was dissolved. The polyolefin solid wax and the polymethylene urea were then dispersed one after the other using a dissolver. The resulting dispersion was then homogenized using a bead mill. Finally, the additive package (comprising rheology additive, leveling additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver. Then the polyamide hardener was added and stirred homogeneously using a dissolver.

[0162] Example 6 (with plastic and wax, according to the invention):

[0163] 64.5 wt.% Methoxypropyl acetate

[0164] 19.4 wt.% Bisphenol A based epoxy resin and a modified polyamide hardener composition (based of a polyamine and a fatty acid)

[0165] 5.0 wt.% Polyetheretherketone (micronized)

[0166] 10.0 wt.% Polyolefin solid wax (micronized)

[0167] 1.1 wt.% (Additive package comprising rheology additive, leveling additive, defoamer)

[0168] 100.0 wt.%The solvent methoxypropyl acetate was placed in a stirring vessel and the epoxy resin was dissolved. The polyolefin solid wax and the polymethylene urea were then dispersed one after the other using a dissolver. The resulting dispersion was then homogenized using a bead mill. Finally, the additive package (comprising rheology additive, flow additive, defoamer) was added to the mixture and the final mixture was homogenized again using a dissolver. Then the polyamide hardener was added and stirred homogeneously using a dissolver.

[0169] Coating of test specimens with the lubricant coating composition to form a dry film lubricant coating (from examples 1 to 4):

[0170] In the next step, the test specimens reguired for characterizing the dry film (test plates from OPTIMOL Instruments Pruftechnik GmbH made of 100Cr6 steel for the subseguent tribological tests and test sheets made of R-35 steel from Q-Labs for the subseguent corrosion resistance tests) were coated. The coating process first involved a priming step with manganese phosphating, whereby phosphate layers with a thickness of approx. 5 pm were produced. The coating formulations (according to examples 1 to 4) were then sprayed on using a standard spray gun. The applied coatings were dried and cured in a standard convection oven for 30 minutes at a temperature of 150°C in all cases. For each lubricant coating to be tested, the same layer thicknesses of around 20 pm (without the phosphate substrate) were set. The layer thickness measurements were carried out using a Fischerscope MMS PC2 in accordance with DIN EN ISO 2178.

[0171] Conducting the material tests:

[0172] Mechanical testing

[0173] - The resulting coatings from examples 1 to 4 were tested for their suitability as lubricant coatings using an SRV® 5 tribometer from OPTIMOL Instruments Pruftechnik GmbH (SRV: vibration, friction, and wear). The friction partners (uncoated cylinder against plate coated with a lubricant coating) were loaded in line contact with a specified normal force and rubbed against each other in an oscillating motion with a defined freguency and amplitude, whereby the coefficient of friction was recorded as a function of time. The tests were carried out in accordance with DIN 51834-1 - 2012- 11 , with the following test parameters deviating from the standard:- Test specimen: Disc 100Cr6 (AISI52100)

[0174] Cylindrical rollers 0: 6 mm,

[0175] L: 8 mm made of 100Cr6 (AISI52100)

[0176] - Cylinder offset: 10°

[0177] - Test frequency: 20 Hz

[0178] - Oscillation amplitude: 2.8 mm

[0179] - Test temperature: 25°C

[0180] - Run-in phase: 2 min 10 N + 1 min 20 N + 1 min 30 N

[0181] - Full load: 60 N (reached after run-in phase)

[0182] - Total running time: 34 minutes

[0183] Fig. 1 shows an example of a measurement record (coefficient of friction vs. time in minutes) from an SRV test run of a coating under the conditions described above. To evaluate the friction behavior of a coating, the coefficient of friction range 2 after the running-in phase 1 under full load from the 5th minute to the 35th minute (end of test) was used and all measured coefficients of friction over this period of 30 minutes were averaged. The resulting average COF is used as a measurement variable to compare the friction behavior of other coatings.

[0184] To evaluate the wear behavior of the layers, the resulting wear track from the SRV test was used, which is created by the frictional contact between the uncoated test cylinder and the lubricant coating on the plate after a defined running time of 34 minutes on the test disc. In order to quantify the wear, the wear marks were measured using a 3D digital microscope from KEYENCE (VK-X 100 Series), whereby wear cross-sections were recorded at a minimum of five different positions in the middle section of the wear mark.

[0185] Fig. 2 shows a schematic representation of the evaluation principle for the wear measurements. The coated test plate 3 with the diamond-shaped wear mark 4 resulting from the SRV test is shown. The marked area 5 of the wear track was defined as the measuring area for recording the wear cross-sections using 3D microscopy. Spread across the area 5, wear cross-sections Mi , M2 , M3 , IVU , Ms , ... . [6] were recorded across the area 5, from which the average cross-sectional area A was formed and used as an evaluation criterion for the wear of the respective lubricant coating.Accordingly, a small value for the average cross-sectional area A indicated low wear, while large cross-sections indicated heavy wear.

[0186] All measurement results from the tribological investigations are summarized in Fig.

[0187] 3 and Fig. 4.

[0188] Fig. 3 shows the averaged coefficients of friction for each measurement, with each average COF value for a measurement represented as a bar. Two measurements are shown for each example. It was found that the two friction coefficient curves over the entire measurement period of the layers from the formulation according to Example 4 (plastic and wax) of the cured lubricant coating with the PTFE-based solid lubricant according to Example 1 (reference) are very similar. A purely waxbased lubricant coating according to Example 3 resulted in higher coefficients of friction, while a coating that contained no wax but only plastic particles (Example 2) failed immediately, resulting in an immediate termination of the test.

[0189] Each friction coefficient measurement resulted in a wear track which (with the exception of Example 2) was measured microscopically as described above. Fig. 4 compares the averaged cross-sectional areas Afrom the middle section of each measured wear track (see Fig. 2 for explanations), with each average value A represented by a bar.

[0190] Fig. 4 illustrates that the combination of plastic and wax according to the invention (Example 4) led to significantly improved wear resistance compared to the PTFE-based reference (Example 1) at comparable coefficients of friction (Fig. 3), which was reflected in a significant reduction in the average wear cross-sections A. If the plastic is not used in the PTFE-free formulation (Example 3), the coefficient of friction increased on the one hand, and wear also increased on the other (increase in the average wear cross-section A). However, the wear was still less pronounced here than with the PTFE reference (from Example 1).

[0191] If the wax is not used in the PTFE-free formulation (Example 2), the coefficient of friction rose sharply, which led to an immediate termination of the test. In this case, no evaluation analogous to the other examples (1 , 3, and 4) was possible.Corrosion tests

[0192] In addition to the tribological investigations (friction properties and wear resistance) of the cured coatings from examples 1 to 4, the corrosion-protective ef-feet of the coatings according to the invention was also investigated.

[0193] The corresponding tests were carried out using a neutral salt spray test NSS in accordance with DIN EN ISO 9227. For this purpose, as described above, test sheets were first subjected to manganese phosphating (steel / type R-35 from Q-Labs) and then coated with the lubricant coating. The lubricant coatings on steel sheets, which contained one of the claimed compositions of micronized plastic and wax particles instead of PTFE, showed at least the same, and in many cases even improved, running times in the salt spray test compared to PTFE-containing lubricant coatings. If the plastic component was omitted from the coating composition, the corrosion protection effect of the layers was significantly reduced compared to steel in the salt spray test.

[0194] The resulting coatings from examples 5 and 6 also show good friction behavior and good wear resistance as well as good corrosion resistance.Serial number Binder(a) Particulate plastics (b) Waxes (c) Solvent (d)

[0195] Polyurethane resins based on aromatic polyPolyetheretherketone

[0196] 1 ols, in particular modified by epoxy groups, in Polyolefin wax, Methoxypropyl (PEEK)

[0197] particular blocked isocyanates especially modified acetate (MPA)

[0198] Polyurethane resins based on aromatic polyPolyphenylene sulfide

[0199] 2 ols, in particular modified by epoxy groups, Methoxypropyl

[0200] (PPS) Rice bran wax

[0201] with in particular blocked isocyanates acetate (MPA)

[0202] Polyurethane resins based on aromatic polyPolymethylene urea 3 ols, in particular modified by epoxy groups, Polyolefin wax, Methoxypropyl (PMU) especially modified acetate (MPA)

[0203]

[0204] with in particular blocked isocyanates

[0205] Epoxy resin, in particular reaction products of Polyphenylene sulfide

[0206] 4 Polyolefin wax, Methoxypropyl bisphenol A and epichlorohydrin, in particular (PPS) especially modified acetate (MPA)

[0207] cured with polyamines

[0208] Polyamideimide resin, in particular based on

[0209] Polyetheretherketone

[0210] 5 trimellitic anhydride (TMA) and 4,4'-diamino- Fischer-Tropsch wax, espeN-Ethyl-2-pyrroli- diphenylmethane (MDA), or with, for example, (PEEK) cially modified done (NEP)

[0211] 4,4'-methylenediphenyl diisocyanate (MDI)

[0212] 6

[0213] Melamine resins, in particular based on melaPolyphenylene sulfide Fischer-Tropsch wax, in

[0214] Butyl acetate (BuAc) mine and formaldehyde, preferably etherified (PPS) particular modified

[0215]

Claims

Claims1. A lubricant composition, the lubricant composition being free of PTFE, comprising the following components:(a) binders selected from one or more members of the group:polyurethanes, melamine resins, epoxy resins cured by reaction of epoxy groups with one or more of aliphatic primary or secondary amines, aromatic primary or secondary amines, each having at least two amine groups, and amides having at least two amide groups and polyamideimide resins;(b) particulate plastics selected from one or more members of the group:polyetheretherketones, polyphenylene sulfides, polysilsesquioxanes, and polymethylene ureas; in particular polyetheretherketones, polyphenylene sulfides, and polymethylene ureas;(c) waxes selected from one or more members of the group:paraffin waxes, modified paraffin waxes, Fischer-Tropsch waxes, modified Fischer-Tropsch waxes, polyolefin waxes, modified polyolefin waxes, carnauba waxes and rice bran waxes,in particular polyolefin waxes, modified polyolefin waxes, carnauba wax and rice bran wax;wherein (b) and (c) are in a weight ratio of 1 :3 to 3:1 , preferably2:1 to 1:2.5, particularly preferably 1.5:1 to 1:2, each based on dry content; and (d) at least 40 wt.%, preferably at least 55 wt.%, of one or more organic solvents selected from the grouporganic solvents containing hydroxy, keto, ester, and / or ether groups, aromatic hydrocarbons, aliphatic hydrocarbons, lactams and amides.

2. The lubricant composition according to claim 1 , further comprising(e) solid lubricants, in particular M0S2 and / or graphite and / or layered silicates; and / or(f) one or more additives selected from the group:emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, colorants, and fillers;preferablyone or more additives selected from the group:(f1) emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, and colorants ,and(f2) fillers.

3. The lubricant composition according to claim 1 or 2, comprising40 to 90 PPW, preferably 65 to 85 PPW, of the binder (a);3 to 30 PPW, preferably 5 to 13 PPW, of particulate plastics (b);7 to 40 PPW, preferably 10 to 22 PPW, of waxes (c);based on the sum of the base components [(a) + (b) + (c)], which is 100 PPW as a reference value, and each based on the dry content.

4. The lubricant composition according to at least one of the previous claims, comprisingless than 100 to 60 PPW of the base components from [(a) + (b) and (c)] and (e) 0 to 30 PPW, preferably 5 to 20 PPW, of solid lubricants consisting of molybdenum disulfide and / or graphite and / or layered silicates;(f) one or more additives selected from the group:emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, colorants, and fillers,of which(f1 ) 0 to 35 PPW, preferably 0.01 to 27 PPW, of one or more additives from the group of emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, and colorants,and / or(f2) 0 to 35 PPW, preferably 1 to 25 PPW, fillersbased on the sum of the components [(a) + (b) + (c)] + (e) + (f) or [(a) + (b) + (c)] + (e) + (f1) + (f2), which is 100 PPW as a reference value, and each based on dry content.

5. The lubricant composition according to at least one of the preceding claims, wherein40 to 97 wt.% of the lubricant composition is / are the organic solvent(s).

6. The lubricant composition according to at least one of the preceding claims, comprising1 to 40 PPW, preferably 12 to 30 PPW, of the binder (a);0.5 to 15 PPW, preferably 1 to 10 PPW, of particulate plastics (b);1 to 20 PPW, preferably 2 to 15 PPW, of waxes (c); and40 to 97 PPW, preferably 60 to 80 PPW, of organic solvents (d);based on the sum of the components [(a) + (b) + (c)] + (d), which is 100 PPW as a reference value and for (a), (b) and (c) each based on dry content.

7. The lubricant composition according to at least one of the preceding claims, comprising1 to 35 wt.%, preferably 10 to 27 wt.%, of the binder (a);0.5 to 13 wt.%, preferably 1 to 9 wt.%, of particulate plastics (b);1 to 18 wt.%, preferably 2 to 12 wt.%, of waxes (c);40 to 96 wt.%, preferably 55 to 75 wt.%, of organic solvents (d);0 to 10 wt.%, preferably 2 to 8 wt.%, of solid lubricants (e);0 to 15 wt.%, preferably 0.01 to 10 wt.%, of additives (f1); and0 to 10 wt.%, preferably 3 to 9 wt.%, of fillers (f2);wherein [(a) + (b) + (c)], (e), (f1) and (f2) are each based on the dry content.

8. The lubricant composition according to at least one of the preceding claims, comprising1-30 wt.% of the binder (a);0.5-10 wt.% of particulate plastics (b);0.5-15 wt.% of waxes (c);40-90 wt.% of organic solvents (d);0-12 wt.% of additives (f1 );0-10 wt.% of fillers (f2);0-3 wt.% residual monomers,0-5 wt.% other binders;0-20 wt.% other organic solvents; and0-2 wt.% water;wherein [(a) + (b) + (c)], (e), (f1) and (f2) are each based on the dry content.

9. The lubricant composition according to at least one of the preceding claims, wherein the particulate plastics (b) and / or the waxes (c) and / or the solid lubricants (e) and / or the solid insoluble additives (f1 ) and / or the fillers (f2) each have a particle diameter of less than 40 pm (D90), preferably less than 25 pm (D90).

10. A lubricant coating as a solid and dry layer, the lubricant coating being free of PTFE, comprising:(a) binders selected from one or more members of the group:polyurethanes, melamine resins, epoxy resins cured by reaction of epoxy groups with one or more of aliphatic primary or secondary amines, aromatic primary or secondary amines, each having at least two amine groups, and amides having at least two amide groups, and polyamideimide resins;(b) particulate plastics selected from one or more members of the group: polyetheretherketones, polyphenylene sulfides, polysilsesquioxanes, and polymethylene ureasin particular polyetheretherketones, polyphenylene sulfides, and polymethylene ureas;(c) waxes selected from the group:paraffin waxes, modified paraffin waxes, Fischer-Tropsch waxes, modified Fischer-Tropsch waxes, polyolefin waxes, modified polyolefin waxes, carnauba waxes, and rice bran waxes,in particular polyolefin waxes, modified polyolefin waxes, carnauba wax and rice bran wax;wherein (b) and (c) are in a weight ratio of 1 :3 to 3:1 , preferably2:1 to 1:2.5, particularly preferably 1.5:1 to 1:2, each based on dry content; and wherein the lubricant coating has a layer thickness of less than 200 pm, preferably less than 40 pm.

11. The lubricant coating according to claim 10, further comprising(e) solid lubricants, in particular M0S2 and / or graphite and / or layered silicates; and / or(f) one or more additives selected from the group:emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, colorants, and fillers;preferablyone or more additives selected from the group:(f1) emulsifiers, stabilizers, corrosion inhibitors, anti-sedimentation additives, wetting and leveling additives, rheology additives, defoamers, UV additives, and colorants, and(f2) fillers.

12. The lubricant coating according to claim 10 or 11, wherein the particulate plastics (b) and / or the waxes (c) and / or the solid lubricants (e) and / or the solid insolu-ble additives (f1 ) and / or the fillers (f2) each have a particle diameter of less than 40 pm (D90), preferably less than 25 pm (D90).

13. The lubricant coating according to at least one of claims 10 to 12, comprising the components according to at least one of claims 3, 4, 6 in the con-centrations or PPW specified therein.

14. A device comprising the lubricant coating according to at least one of claims 10 to 13, wherein the device is made of metal, ceramic, or plastic.

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