High-temperature grease

Abstract

The invention relates to a high-temperature grease comprising (A) 20 to 88 wt %, based on the overall weight of the grease, of a base oil, (B) 1 to 55 wt. %, based on the overall weight of the grease, of a fluorine-free material, said fluorine-free material having an average particle size (D50) of less than 80 μm wherein the grease does not contain polytetrafluorothylene and/or contains polytetrafluorothylene in a proportion of less than 4 wt. %, based on the overall weight of the grease.

1 : A lubricating grease comprising:
 (A) 20 wt. % to 88 wt. % based on the overall weight of the lubricating grease, of a base oil; and   (B) 1 wt. % to 55 wt. %, based on the overall weight of the lubricating grease, of a fluorine-free material, wherein the fluorine-free material has an average particle size (D50) of less than 80 μm, measured according to ISO 13320-1, publication date 2020-01, and is selected from the group consisting of:
 (B1) a fluorine-free polymer which has aromatic, heteroaromatic and/or heterocyclic groups and a melting or decomposition point, measured according to DIN EN ISO 11357-1, publication date 2008.04, of above 200° C.; fluorine-free phthalocyanine and mixtures thereof; 
 (B2) silicone resin, lignin and mixtures thereof; 
 (B3) inorganic layered silicate, talcum, bentonite, mica, pyrogenic silicon dioxide, pyrogenic silicon dioxide functionalized with organic groups and mixtures thereof; 
 (B4) nanoparticulate silicon dioxide functionalized with organic groups; 
 (B5) a phosphorus compound, zinc pyrophosphate, calcium (pyro)phosphate, and/or zirconium hydrogen phosphate, and mixtures thereof; 
 (B6) a melamine derivative, melamine cyanurate, melamine phosphate, and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione; and 
 (B7) fluorine-free materials selected from two or more than two of groups B1, B2, B3, B4, B5 and/or B6; 
   wherein the lubricating grease does not contain polytetrafluoroethylene, and/or contains polytetrafluoroethylene in a proportion of less than 4 wt. % based on the overall weight of the lubricating grease.   
     
     
         2 : The lubricating grease according to  claim 1 , wherein the fluorine-free material is a fluorine-free polymer in accordance with option B1 and has a numerical ratio of aromatic carbon atoms and/or of carbon atoms contained in heteroaromatic structures of at least 20%, each based on the overall number of carbon atoms in the fluorine-free polymer. 
     
     
         3 : The lubricating grease of  claim 1 , wherein the fluorine-free material is a fluorine-free polymer in accordance with option B1 and is selected from the group consisting of polyaryletherketone (PAEK), polyetheretherketone (PEEK), crosslinked PAEK, crosslinked PEEK, polyphenylene sulfide (PPS), polyethersulphone (PES), poly(amide)imide (PAI), perylene imide, polycarbonate (PC), polyquinoline, polyquinoxaline, morpholine, phthalocyanine, melamine resin, and blends thereof. 
     
     
         4 : The lubricating grease of  claim 1 , wherein the fluorine-free material is crosslinked PAEK, and/or crosslinked PEEK. 
     
     
         5 : The lubricating grease of  claim 1 , wherein the fluorine-free material
 contains two or more of the fluorine-free materials of group B3 in combination, in particular talcum in combination with pyrogenic silicon dioxide, functionalized with organic groups, and/or   contains at least one fluorine-free material selected from group B3 in combination with at least one fluorine-free material selected from group B6, in particular, pyrogenic silicon dioxide functionalized with organic groups, in combination with melamine cyanurate, and/or   contains at least one fluorine-free material selected from group B3, in combination with at least one fluorine-free material selected from group B6, in combination with hexagonal boron nitride, and/or   contains at least one fluorine-free material selected from group B3, in combination with hexagonal boron nitride.   
     
     
         6 : The lubricating grease of  claim 1 , wherein the fluorine-free material contains pyrogenic silicon dioxide functionalized with organic groups, in combination with melamine cyanurate and in combination with hexagonal boron nitride. 
     
     
         7 : The lubricating grease of  claim 1 , wherein the fluorine-free material contains pyrogenic silicon dioxide functionalized with organic groups, in combination with melamine cyanurate and in combination with hexagonal boron nitride. 
     
     
         8 : The lubricating grease of  claim 1 , wherein the fluorine-free material and/or the lubricating grease is NSF/H1 approved. 
     
     
         9 : The lubricating grease of  claim 1 , wherein the fluorine-free material functions as a thickener and the proportion of the fluorine-free material in relation to the overall weight of the lubricating grease is 10 to 55 wt. %. 
     
     
         10 : The lubricating grease of  claim 9 , wherein the lubricating grease contains a further thickener, other than the fluorine-free material, in a proportion of 3 wt. % to 30 wt. % based on the overall weight of the lubricating grease. 
     
     
         11 : The lubricating grease of  claim 1 , wherein the fluorine-free material functions as an additive to reduce the coefficient of friction, wherein the proportion of the fluorine-free material, based on the overall weight of the lubricating grease, is from 1 wt. % to 10 wt. %. 
     
     
         12 : The lubricating grease of  claim 11 , wherein the lubricating grease contains a thickening agent, other than the fluorine-free material, in a proportion of 3 wt. % to 40 wt. % based on the overall weight of the lubricating grease. 
     
     
         13 : The lubricating grease of  claim 1 , wherein the base oil is selected from the group consisting of esters, dipentaerythrite esters, trimellitic acid esters, hemimellitic acid esters, pyromellitic acid esters, estolides, pentaerythrite esters, dimer acid esters, trimer acid esters, trimethylol propane esters (TMP esters); ethers, polyphenylene ethers, diaryl ethers, triaryl ethers, polyglycols, linear or branched perfluoro polyether oils (PFPE oils); synthetic hydrocarbons, alkylzied naphthalines, polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs); untreated and chemically modified vegetable oils, group III oils; gas-to-liquid (GTL) oils; dimethyl silicone oils; arylized silicone oils, alcylaryl silicone oils, methyl-aryl silicone oils and completely arylized silicone oils, which can be used alone or in combination. 
     
     
         14 : The lubricating grease of  claim 1 , wherein the fluorine-free material is inorganic layered silicate, talcum, bentonite, mica, pyrogenic silicon dioxide, pyrogenic silicon dioxide functionalized with organic groups, and/or mixtures thereof, in combination with a layered solid lubricant that is not an inorganic layered silicate. 
     
     
         15 : A method of manufacturing the lubricating grease of  claim 1 , comprising mixing of the following components:
 (A) 20 wt. % to 88 wt. % based on the overall weight of the lubricating grease, of a base oil,   (B) 1 wt. % to 55 wt. %, based on the overall weight of the lubricating grease, of a fluorine-free material, wherein the fluorine-free material has an average particle size (D50) of less than 80 μm, measured according to ISO 13320-1, publication date 2020-01, and is selected from the group consisting of:
 (B1) a fluorine-free polymer which has aromatic, heteroaromatic and/or heterocyclic groups and a melting or decomposition point, measured according to DIN EN ISO 11357-1, publication date 2008.04, of above 200° C.; fluorine-free phthalocyanine and mixtures thereof; 
 (B2) silicone resin, lignin and mixtures thereof; 
 (B3) inorganic layered silicate, talcum, bentonite, mica, pyrogenic silicon dioxide, pyrogenic silicon dioxide functionalized with organic groups and mixtures thereof; 
 (B4) nanoparticulate silicon dioxide functionalized with organic groups; 
 (B5) a phosphorus compound, zinc pyrophosphate, calcium (pyro)phosphate, and zirconium hydrogen phosphate, and/or mixtures thereof; 
 (B6) a melamine derivative, melamine cyanurate, melamine phosphate, and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione; 
 (B7) fluorine-free materials selected from two or more than two of groups B1, B2, B3, B4, B5 and/or B6; 
 wherein the lubricating grease does not contain polytetrafluoroethylene, and/or contains polytetrafluoroethylene in a proportion of less than 6 wt. %, even more preferably less than 4 wt. %, even more preferably less than 2 wt. %, even more preferably less than 1 wt. %, even more preferably less than 0.1 wt. %, in each case based on the overall weight of the lubricating grease. 
   
     
     
         16 : A use of the lubricating grease of  claim 1  for the lubrication of tribological systems, in applications in which a high top usage temperature of more than 160° C. is necessary, and/or for the lubrication of tribological systems in which an application spectrum is necessary in the temperature range from −40° C. to 160° C. 
     
     
         17 : A use of the lubricating grease of  claim 1  for the lubrication of tribological systems, which are in contact with foodstuffs and/or drinking water, in particular, of working apparatus in food processing and/or for gas and (drinking) water fittings. 
     
     
         18 : The use according to  claim 17 , wherein the fluorine-free material is silicone resin, lignin and mixtures thereof (option B2) and the lubricating grease is used for the lubrication of working apparatus in food processing and/or for gas and (drinking) water fittings. 
     
     
         19 : A use of the lubricating grease of  claim 1  for the lubrication of tribological systems, which are in contact with foodstuffs and/or drinking water, in a working apparatus in food processing, chains for transport in freezing tunnels and conveyer belts, transmissions, antifriction and plain bearings, pneumatic cylinders, seals, installation pastes, valves and fittings, or for gas and (drinking) water fittings; and/or for the lubrication of components in the automotive industry, in ball-type linear drives in automotive steering applications, actuators; transmissions, plastic transmissions, seals, seals in sliding sunroofs, brake boosters and/or antifriction bearings, plain bearings and/or linear guides.