Patent GB-890386-A (GB)
Title: A polypropylene grease
Inventor: MORWAY ARNOLD JESSE
IPC: C08F210/06
Filed: 1959-08-11
Abstract: A lubricating grease composition, having an unworked penetration above 250 mm./10 at 77 DEG F. and a dropping point of at least 500 DEG F., comprises an oil-soluble amorphous polypropylene having a molecular weight in the range 300-10,000 and an intrinsic viscosity up to 0,4, 1-5 wt. per cent of an isotactic polypropylene having a molecular weight in the range 100,000-1,000,000 and a melting point in the range 250 DEG -410 DEG F., and 5-35 wt. per cent of a soap-salt thickener, the amount of the amorphous polypropylene being sufficient to disperse the isotactic polypropylene.  The soap-salt thickener comprises soaps of one or more C8-C30 car-boxylic acids (e.g. caprylic, lauric, stearic, mono-or dihydroxy stearic, arachidic, oleic or ricinoleic acid, or acids derived from coconut oil, hydrogenated fish oil or tallow) and salts of one or more C1-C6 carboxylic acids (e.g. formic, acetic, propionic, furoic, acrylic, adipic or lactic acid).  These soaps and salts may be calcium, barium, strontium or magnesium soaps and salts and may be preformed or formed in situ by reaction between the free acids and the metal base.  The composition may contain a lubricating oil which may be a mineral, synthetic, animal, vegetable or fish oil or a blended oil. Hydrogenated oils, white oils, shale oil and hydrogenated or voltolized fatty oils are mentioned.  Specified synthetic oils are olefin polymers, reaction products of oxides of carbon with hydrogen, esters of dibasic acids (e.g. di-2-ethyl hexyl sebacate), glycol esters (e.g. C13 oxo acid diester of tetraethylene glycol) and complex esters.  The composition may also contain dyes, heat-thickened fatty oils, sulphurized fatty oils, organometallic compounds, antioxidants, other thickeners, viscosity index improvers, oiliness agents, resins, rubber, other olefin polymers, voltolized fats, voltolized mineral oils, voltolized waxes, colloidal solids (e.g. graphite or zinc oxide) and solvents or assisting agents (e.g. esters, ketones, alcohols, aldehydes and halogenated or nitrated compounds).  In the examples, lubricating greases are described which are prepared from (a) acetic acid, coconut oil fatty acids, hydrated lime, phenyl alpha naphthylamine, isotactic polypropylene and amorphous polypropylene, with or without mineral lubricating oil and (b) acetic acid, stearic acid, 12-hydroxystearic acid, hydrated lime, phenothiazine, isotactic polypropylene, amorphous polypropylene and di-2-ethyl hexyl sebacate.  The effects of modifying composition (a) by replacing the amorphous polypropylene by mineral oil or liquid polypropylene are described.  For comparative purposes, lubricating greases are described which are prepared from (c) acetic acid, 12-hydroxystearic acid, stearic acid, hydrated lime and mineral oil or (d) amorphous polypropylene, isotactic polypropylene and mineral oil.ALSO:A grease composition comprises an oil-soluble amorphous polypropylene having a molecular weight in the range 300-10,000 and an intrinsic viscosity up to 0,4, 1-5 wt. per cent of an isotactic polypropylene having a molecular weight in the range 100,000-1,000,000 and a melting point in the range 250 DEG -410 DEG F., and 5-35 wt. per cent of a soap-salt thickener, the amount of the amorphous polypropylene being sufficient to disperse the isotactic polypropylene.  The soap-salt thickener comprises soaps of one or more C8-C30 carboxylic acids (e.g. fatty acids) and salts of one or more C1-C6 carboxylic acids (e.g. formic, acetic, propionic, furoic, acrylic, adipic or lactic acid).  These soaps may be alkaline earth metal or magnesium soaps and salts and may be preformed or formed in situ by reaction between the free acids and the metal base.  The composition may contain a lubricating oil which may be a mineral, fatty or synthetic oil or a blended oil.  In the examples, greases are described which are prepared from (a) acetic acid, coconut oil fatty acids, hydrated lime, phenyl alpha naphthylamine, isotactic polypropylene and amorphous polypropylene, with or without mineral oil and (b) acetic acid, stearic acid, 12-hydroxystearic acid, hydrated lime, phenothiazine, isotactic polypropylene, amorphous polypropylene and di-2-ethyl hexyl sebacate.