Patent GB-764183-A (GB)
Title: Methods of controlling the quality of lubricating oils during their manufacture or blending
Inventor: MATTHEWS JOHN BRYANT
IPC: G01N13/00
Filed: 1953-08-24
Abstract: A method of controlling the quality of hydrocarbon lubricating oils during their manufacture or blending comprises periodically testing the oil being produced to determine a parameter of the work of adhesion thereof on a solid surface and, if and when necessary, adjusting one or more of the conditions of the process of manufacture or of the blending to ensure that the value of the parameter is maintained between limits predetermined experimentally according to the use to which the lubricating oil is to be put.  Suitable parameters of the work of adhesion are the spreading pressure of the lubricating oil on a solid surface and the heat liberated when a solid surface is completely wetted by the lubricating oil, and the measurement of these quantities is described.  The method of controlling the quality of the oils is applicable to the hydrocarbon oils used for the lubrication of engines, lathes and other machinery and may be applied to the manufacture or blending of bright stocks, gear oils, spindle oils and penetrating oils.  The method may be applied to mineral lubricating oils that are produced either as distillates or as residues, to the refining of hydrocarbon lubricating oils by treatments such as solvent extraction, sulphuric acid treatment and/or clay treatment, to the manufacture of synthetic hydrocarbon oils, for example polymerized olefins and alkylated aromatic hydrocarbons such as polytertiary butyl naphthalenes, and to the blending of mixtures of mineral lubricating oils with synthetic lubricating oils.  It is also applicable to the blending of hydrocarbon oils with organic, inorganic or organometallic compounds. According to a modification of the method, an alteration in composition is periodically artificially induced in a sample of the oil being produced, this alteration simulating that which will occur during the intended use of the oil, a parameter of the work of adhesion of the altered sample on a solid surface is determined and, if and when necessary, one or more of the conditions of the process of manufacture or of the blending is adjusted to ensure that the parameter of the work of adhesion of the so altered samples is maintained between limits predetermined experimentally according to the use to which the lubricating oil is to be put.  In the examples, (1) a mixture of mineral lubricating oils is blended with a solvent-refined mineral lubricating oil in such proportions that the measured spreading pressure on steel of the oil blend exceeds 20 dynes/cm., (2) the conditions of absorbent earth finishing treatment employed in the manufacture of a mineral lubricating oil are adjusted so that the measured spreading pressure on steel of the oil (after heating in air under specified conditions) exceeds 15 dynes/cm., (3) a mixture of crude mineral oils is solvent extracted with liquid SO2 and the raffinate is treated with a mixture of adsorbent earth and lime, the earth being so chosen that the measured spreading pressure on steel of the refined oil (after heating in air under specified conditions) exceeds 15 dynes/cm., (4) crude mineral oil is solvent extracted with liquid SO2 and the raffinate is treated with a mixture of adsorbent earth and lime, the temperature of this treatment being so chosen that the measured spreading pressure on steel of the refined oil (after heating in air under specified conditions) exceeds 15 dynes/cm., (5) mineral lubricating oil is solvent extracted with liquid SO2 and the raffinate is treated with adsorbent earth, a treatment of the raffinate with sulphuric acid being interposed between the solvent extraction and the earth treatment whenever the measured spreading pressure on steel of the refined oil (after heating in air under specified conditions) falls below 15 dynes/cm. and (6) a mineral lubricating oil blend is manufactured by a process which includes, as the finishing step, treatment with adsorbent earth, the earth used and/or the proportion of earth used being chosen so that the refined oil has a measured spreading pressure on steel in excess of 18 dynes/cm.