Method for the preparation of lubricating greases thickened with polyurea, based on lignin derivatives, those lubricating greases and uses thereof

摘要

Process for preparing a lubricating grease containing lignin derivative comprising the following steps: - joining an amine component with an isocyanate component in a first base oil and converting the same to form a polyurea thickener; - heating above 120 ° C to produce a base fat containing at least polyurea thickener, comprising at least the first base oil; and - cooling the base fat; the process comprising the step of combining with a lignin derivative and the step of subjecting the lignin derivative to an elevated temperature of more than 110 ° C in the first and / or second base oil and subjecting the lignin derivative and the polyurea thickener or the amine component and the isocyanate component together at a temperature greater than 120 ° C in the base oil for at least 30 minutes, and using the isocyanate component with a stoichiometric excess of isocyanate groups with respect to the reactive amine groups including possible reactive -OH groups of the amine component such that a portion of the isocyanate groups of the isocyanate component reacts with the lignin derivative, the lignin derivative being a lignosulfonate or a kraft lignin or an organosolv ligninv or their mixtures; and the lubricating grease containing lignin derivative having: 55 to 92% by weight of the base oil; 5 to 20% by weight of the polyurea thickener; and 0.5 to 15% by weight of the lignin derivative; as well as possibly one or more of the following optional components: 0 to 40% by weight additives; 0 to 20% by weight of soap thickener or complex soap thickener based on calcium, lithium or aluminum salts; 0 to 20% by weight of inorganic thickener; 0 to 10% by weight of solid lubricant.