| abstract |
Greases comprise a lubricating oil, an oleophilic clay, and a metal carbonate in which there is a metal of Group Ia, Ib, IIb, IVb, VIIa or VIII of the Mendeleeff Periodic Table. The oil may be mineral or synthetic, the latter including aliphatic dicarboxylic acid esters such as bis(2-ethylhexyl) sebacate, and aliphatic silicates, fluorates, and phosphates. The clay may be a montmorillonite (of Na, K or Li), Wyoming bentonite, or hectorite modified with an imidazoline and/or an amino-amide formed between certain fatty acids and polyethylene polyamines. Typical of many specified imidazolines are 4-octadecyl-, 2-b -hydroxyethyl-4-undecyl-, and 1-diethylenediamino-2-hexadecylimidazolines. The carbonates specified are naturally occurring ones such as Ankerite, Malachite, and Rhodochrosite. The greases may also contain one or more of the following additives:- (1) an inorganic sulphide (e.g. molybdenum disulphide, an amorphous antimony tri-, tetra- or penta-sulphide, or mixtures thereof), (2) a lead naphthenate, (3) an imidazoline and/or amino-amide of the type used to modify the clay, but present in addition to those associated with the clay, (4) an aromatic amine (examples given), (5) sodium or potassium nitrite, and (6) terpene-phosphorus chloride reaction products. |