Patent GB-473502-A (GB)
Title: Improvements relating to lubricating compositions
IPC: C10M159/08
Filed: 1936-07-30
Abstract: <PICT:0473502/III/1> A lubricant of increased viscosity index and oiliness and decreased Sligh value and pour point comprises a mineral lubricating oil having dissolved therein a polymer of a non-hydroxylated semi- or non-drying fatty oil prepared by heating the oil between 500 and 610 DEG  F. under a pressure less than 200 mm. of mercury until the polymer has a viscosity of at least 1000 seconds Saybolt at 210 DEG  F. and preferably between 3000 and 7000 seconds.  The oils polymerized have iodine numbers of 10 to 125 and include rapeseed, cottonseed, and mustard seed oils; fish oils of the stated iodine value; and the last together with palm or lard oils; there may be added 10 to 60 per cent of hydrocarbon oil, preferably of high boiling point and having a viscosity of 50 or more seconds Saybolt at 210 DEG  F.; small amounts of heavy metal soaps as catalysts; or sulphur (preferably less than 0,5 per cent).  Acid formed during polymerization may be removed by washing with soda or by adding a light hydrocarbon lubricating oil, e.g. spindle oil or "neutral oil" (a distillate lubricating oil), and flashing.  Heavier constituents may be removed by precipitation by liquid propane or butane, alcohols, e.g. amyl or butyl, esters, or ketones, e.g. acetone or methyl ethyl ketone, used alone or mixed with naphtha or aromatic hydrocarbons.  The polymerization may be carried out in the apparatus shown in the Figure.  The oil is passed through the heating coil 3 to the autoclave 4 of iron, nickel or "Monel" (Registered Trade Mark) metal.  A vapour outlet 6 is connected through a trap 5 to a cooler 7 and separator 8, the pressure being reduced by a pump 9. Oil leaving 4 by the pipe 10 may be removed from the system or re-cycled by a pump 11.  The heating means 4a may be replaced by a jacket through which superheated steam, or mercury or diphenyl vapour can be passed or by internal electric heaters.  A series of such apparata may be used or a single autoclave may be internally constructed to provide a tortuous path for the oil.  In examples of the polymerization process: cottonseed oil is heated at 580 DEG  F. under 10 mm. pressure for 20 hours to give a product of viscosity 13,720; rapeseed oil is heated at 600 DEG  F. under 5 mm. pressure giving a product of viscosity 1750 in 10 hours; at 575--590 DEG  F. under 5--7 mm. and 10 mm. pressure giving products of viscosities 6000 and 1000 respectively in 20 hours; at 575--590 DEG  F., 590--600 DEG  F. and 600--610 DEG  F. under 5 mm. pressure to give products of viscosities 6000 after 20 hours, 7000 after 16 hours, and 10,000 after 12 hours respectively; at 580 DEG  F. under 10 mm. pressure for 12 and 20 hours to give products of viscosities 3500 and 6550 respectively.  In examples of lubricants according to the invention, there are added to lubricating oils polymers prepared from rapeseed oil (alone or in the presence of 0,5 per cent of sulphur), from equal quantities of rapeseed oil and an S.A.E. 50 mineral oil, or from equal quantities of rapeseed oil and red lubricating oil in the presence of 0,3 per cent of sulphur; and equal quantities of rapeseed oil and a mineral oil of viscosity 62 are heated at 590 DEG  F. under 5 mm. pressure for 16 hours to give a polymer of viscosity 1200.  (In the above examples all viscosities are given in seconds Saybolt at 210 DEG  F.)  Specification 451,372 is referred to.