Process for the Preparation of Polyurea-Thickened Lignin Derivative-Based Lubricating Greases, Such Lubricant Greases and Use Thereof
AssigneeFuchs Petrolub SE
InventorsThomas Litters, Florian Hahn, Torsten Goerz, Hans Jürgen Erkel
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Abstract
The invention relates to a method for preparing lignin derivative-based lubricating greases thickened by a polyurea thickener, lubricating greases thus prepared, and the use of such lubricant greases, inter alia, in transmissions, constant-velocity driveshafts and sealed roller bearings.
Claims18
A method to prepare a lignin derivative-containing lubricating grease comprising the following steps:
- bringing together an amine component with an isocyanate component in a first base oil and converting the same into a polyurea thickener;
- heating above 120° C. to produce a base grease containing at least a polyurea thickener, comprising at least the first base oil;
- and
- cooling the base grease;
- in which the method comprises the step of bringing together with a lignin derivative and the step of subjecting the lignin derivative to an elevated temperature greater than 110° C. in the first and/or in a second base oil.
The method according to at least one of the preceding claims, in which the second base oil is chemically the same or chemically different from the second base oil.
The method according to at least one of the preceding claims, in which the lignin derivative in the second base oil is subjected to the increased temperature separately from the base grease, and the composition comprising a second base oil and lignin derivative is added to the base grease during cooling or after cooling the base grease, in particular at temperatures below 120° C., preferably below 100° C. and with particular preference below 80° C.
The method according to at least one of the preceding claims, in which the amine component has monoaminohydrocarbyl, di- and/or polyaminohydrocarbylene compounds and also possibly other compounds which are reactive with isocyanate compounds, such as in particular monohydroxycarbyl, di- or polyhydroxyhydrocarbylene or aminohydroxyhydrocarbylene compounds, in which the hydrocarbyl or the hydrocarbylene group(s) preferably have 6 to 20 carbon atoms in each case, with particular preference 6 to 15 carbon atoms.
The method according to at least one of the preceding claims, in which the isocyanate component comprises mono- or polyisocyanates and the polyisocyanates are hydrocarbons with two or more isocyanate groups, preferably in each case with 5 to 20, in particular 6 to 15 carbons and furthermore preferably containing aromatic groups.
The method according to at least one of the preceding claims, in which the isocyanate component is used with a stoichiometric excess of isocyanate groups with respect to the reactive amine groups, including possible reactive hydroxyl groups of the amine component, preferably using an isocyanate excess of 0.1 to 10 mole percent, preferably 5 to 10 mole percent.
The method according to at least one of the preceding claims, in which a portion of the isocyanate groups of the isocyanate component also react with reactive groups of the lignin derivative.
The method according to at least one of the preceding claims, in which the lignin derivative is a lignosulfonate or a kraft lignin or an organosolv lignin or their mixtures;
The method according to at least one of the preceding claims, in which the lignin derivative is obtainable from softwood.
The method according to at least one of the preceding claims, in which the base oil has a kinematic viscosity of 20 to 2500 mm2/s, in particular of 40 to 500 mm2/S at 40° C.
The method according to at least one of the preceding claims, in which the lubricating grease includes one or more additives selected from one or more of the following groups:
- antioxidants such as amine compounds, phenol compounds, sulfur antioxidants, zinc dithiocarbamate or zinc dithiophosphate;
- high-pressure additives such as organochlorine compounds, sulfur, phosphorus or calcium borate, zinc dithiophosphate, organobismuth compounds;
- C2- to C6-polyols, fatty acids, fatty acid esters or animal or vegetable oils;
- anticorrosion agents such as petroleum sulfonate, dinonylnaphthalene sulfonate or sorbitan esters;
- metal deactivators such as benzotriazole or sodium nitrite;
- viscosity promoters such as polymethacrylate, polyisobutylene, oligo-dec-1-ene and polystyrenes;
- wear-protection additives such as molybdenum dialkyl dithiocarbamate or molybdenum sulfide dialkyl dithiocarbamate, aromatic amines;
- friction modifiers such as functional polymers like oleylamides, organic compounds based on polyethers and amides or molybdenum dithiocarbamate;
- and
- solid lubricants such as polymer powders like 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 calcium carbonate, sodium and calcium phosphates;
- and these are preferably added to the base grease at temperatures below 100° C., in particular below 80° C., particularly in the cooling phase.
A lubricating grease obtainable by a method according to at least one of the preceding claims.
Dependencies are inferred from the claim text.