High-temperature grease

Abstract

A high-temperature grease is disclosed comprising (A) 20 to 88 wt %, based on the total weight of the high-temperature grease, of a base oil, (B) 1 to 55 wt. %, based on the total weight of the high-temperature grease, of a fluorine-free material, the fluorine-free material having an average particle size (D50) of less than 80 μm and being 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 above 200° C., fluorine-free phthalocyanin, and mixtures thereof; (B2) a melamine derivative, and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione; and (B3) mixtures which contain a fluorine-free polymer and/or a fluorine-free phthalocyanin according to option B1 and a melamine derivative and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione according to option B2, wherein the high-temperature grease does not contain polytetrafluorothylene and/or contains polytetrafluorothylene in a proportion of less than 6 wt. %, based on the total weight of the grease.

1 . A high-temperature lubricant grease comprising:
 (A) 20% to 88% by weight, based on the total weight of the high-temperature lubricant grease, of a base oil; and   (B) 1% by weight to 55% by weight, based on the total weight of the high-temperature lubricant grease, of a fluorine-free material, where the fluorine-free material has a median particle size (D50) of below 80 μm, measured to ISO 13320-1, 2020-01 edition, and is selected from the group consisting of:
 (B1) a fluorine-free polymer having aromatic, heteroaromatic and/or heterocyclic groups and a melting point or decomposition point, measured to DIN EN ISO 11357-1, 2008.04 edition, of higher than 200° C., and/or fluorine-free phthalocyanine and mixtures thereof; 
 (B2) a melamine derivative, melamine cyanurate, melamine phosphate and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione; and 
 (B3) mixtures containing a fluorine-free polymer and/or fluorine-free phthalocyanine according to option B1 and a melamine derivative and/or 1,3,5-triazine-2,4,6 (1H,3H,5H)-trithione according to option B2: 
   wherein the high-temperature lubricant grease does not contain any polytetrafluoroethylene and/or contains polytetrafluoroethylene in a proportion of less than 6% by weight, based on the total weight of the lubricant grease.   
     
     
         2 . The high-temperature lubricant grease of  claim 1 , wherein the fluorine-free polymer has a numerical proportion of aromatic carbon atoms and/or of carbon atoms present in heteroaromatic structures of at least 20%, based on the total number of carbon atoms in the fluorine-free polymer. 
     
     
         3 . The high-temperature lubricant grease of  claim 1 , wherein the heteroaromatic groups and/or the heterocyclic groups independently contain nitrogen, oxygen and/or sulfur. 
     
     
         4 . The high-temperature lubricant grease of  claim 1 , wherein the fluorine-free polymer is selected from the group consisting of: polyaryletherketone (PAEK), polyetheretherketone (PEEK), crosslinked PAEK, crosslinked PEEK, polyphenylsulfide (PPS), polyethersulfone (PES), poly(amide)imide (PAI), peryleneimide, polycarbonate (PC), polyquinoline, polyquinoxaline, morpholine, phthalocyanine, melamine resin, and blends thereof. 
     
     
         5 . The high-temperature lubricant grease of  claim 1 , wherein the fluorine-free material, the fluorine-free polymer and/or the high-temperature lubricant grease meets NSF/H1 grade. 
     
     
         6 . The high-temperature lubricant grease of  claim 1 , wherein the fluorine-free material functions as a thickener and the proportion of the fluorine-free material based on the total weight of the high-temperature lubricant grease, is 10% to 55% by weight. 
     
     
         7 . The high-temperature lubricant grease of  claim 6 , wherein the high-temperature lubricant grease contains a further thickener other than the fluorine-free material used in accordance with the invention, in a proportion of 3% by weight to 30% by weight, based on the total weight of the lubricant grease. 
     
     
         8 . The high-temperature lubricant grease of  claim 1 , wherein the fluorine-free material functions as an additive for lowering the friction value, where the proportion of the fluorine-free material based on the total weight of the high-temperature lubricant grease, is from 1% by weight to 10% by weight. 
     
     
         9 . The high-temperature lubricant grease of  claim 8 , wherein the high-temperature lubricant grease contains a thickener other than the fluorine-free material used in accordance with the invention; in a proportion of 3% by weight to 40% by weight, based on the total weight of the lubricant grease. 
     
     
         10 . The high-temperature lubricant grease of  claim 1 , wherein the base oil is selected from the group consisting of: esters, dipentaerythritol esters, trimellitic esters, hemimellitic esters, pyromellitic esters, estolides, pentaerythritol esters, dimeric acid esters, trimeric acid esters, trimethylolpropane esters (TMP esters); ethers, polyphenyl ethers, diaryl ethers, triaryl ethers, polyglycols, linear or branched perfluoropolyetherols (PFPE oils); synthetic hydrocarbons, alkylated naphthalenes, polyalphaolefins (PAOs), metallocene polyalpha¬olefins (mPAOs); untreated and chemically modified vegetable oils; group III oils; gas to liquid (GTL) oils; dimethylsilicone oils; arylated silicone oils, alkyl aryl silicone oils, methyl/aryl silicone oils and fully arylated silicone oils, which may be used individually or in combination. 
     
     
         11 . The high-temperature lubricant grease of  claim 1 , wherein the base oil has a kinematic viscosity, determined to ASTM-D-742 September 2014 edition, at 40° C. of 30 mm 2 /sec to 2000 mm 2 /sec. 
     
     
         12 . A process for producing a high-temperature lubricant grease, comprising the blending of the following components:
 (A) 20% to 88% by weight, based on the total weight of the high-temperature lubricant grease, of a base oil; and   (B) 1% by weight to 55% by weight, based on the total weight of the high-temperature lubricant grease, of a fluorine-free material, where the fluorine-free material has a median particle size (D50) of below 80 μm, measured to ISO 13320-1, 2020-01 edition, and is selected from the group consisting of;
 (B1) a fluorine-free polymer having aromatic, heteroaromatic and/or heterocyclic groups and a melting point or decomposition point, measured to DIN EN ISO 11357 -1, 2008.04 edition, of higher than 200° C. and/or, fluorine-free phthalocyanine and mixtures thereof; 
 (B2) a melamine derivative, melamine cyanurate, melamine phosphate and/or 1,3,5-triazine-2,4,6(1H,3H,5H)-trithione, and 
 (B3) mixtures containing a fluorine-free polymer and/or fluorine-free phthalocyanine according to option B1 and a melamine derivative and/or 1,3,5-triazine-2,4,6(1H,3H,5H)-trithione according to option B2; 
 wherein the high-temperature lubricant grease does not contain any polytetrafluoroethylene and/or contains polytetrafluoroethylene in a proportion of less than 6% by weight, based on the total weight of the lubricant grease 
   
     
     
         13 . The use of the high-temperature lubricant grease of  claim 1  for lubrication of tribological systems in applications where an upper use temperature of more than 160° C, is necessary. 
     
     
         14 . The use of  claim 13 , wherein the high-temperature lubricant grease is used for lubrication of slide bearings, of chains or ball bearings and/or for driving of production plants in the chemical industry that are operated at least temporarily at temperatures of more than 160° C. 
     
     
         15 . The use of the high-temperature lubricant grease of  claim 1  for lubrication of slide bearings, gas fittings, actuators, linear guides, closed-loop and open-loop control flaps in an intake manifold, couplings, screws, bolts, fittings, chains for the food industry, especially in bread and waffle baking machines; of ball bearings, espeeially ball bearings for wood pressing plants or corrugated cardboard plants and/or for driving of production plants in the chemical industry, wherein the slide bearings, the ball bearings and/or the production plants in the chemical industry are operated at least temporarily at temperatures of above 160° C.