Patent GB-1099478-A (GB)
Title: Preparation of metal organo dithiophosphates
IPC: C07F9/6571
Filed: 1965-04-05
Abstract: A lubricating composition comprises a lubricating oil fraction and a metal salt of an organo dithiophosphoric acid prepared by reacting P2S5 with a slurry comprising a mixture of at least one organic hydroxy compound having 1-30 carbon atoms and at least one metal in finely divided form selected from the metals above hydrogen in the electromotive series, the quantity of metal in said slurry being at least 90% of the amount of metal theoretically required to convert the organo dithiophosphoric acid to a metal diorgano dithiophosphate. The lubricating oil composition may contain from 0.03 to 5% by weight or more of the metal organo dithiophosphate and other conventional additives may also be present.  The lubricating oil may be an animal, vegetable or mineral or a synthetic hydrocarbon oil and other synthetic oils include those of the ester type such as di-2-ethylhexyl sebacate and carbonate, phosphate and glycol esters as well as polysilicones and halogenated hydrocarbons.  The additives may also be employed in a concentration of 0.02 to 2 weight per cent in petroleum middle distillate fuels, including jet fuels, diesel fuels and heating oils.ALSO:A metal salt of an organo dithiophosphoric acid is obtained by reacting P2S5 with a slurry comprising a mixture of at least one organic hydroxy compound having in the range of from 1 to 30 carbon atoms and at least one metal in finely divided form selected from the metals above hydrogen in the electromotives series, the quantity of metal in said slurry being at least 90% of the amount of metal theoretically required to convert the organo dithiophosphoric acid to a metal diorgano dithiophosphate. The reaction is effected by preparing a slurry of the finely divided metal, preferably of particle size less than 200 mesh and in a 5-10% by weight excess of the theoretical amount, in an organic hydroxy compound and reacting the slurry with a theoretical amount of P2S5, the latter being added to the slurry in small increments over a period of about 1-8 hours, continuous addition being preferred.  In the case of zinc salts a temperature of about 115-200 DEG  F. is suitable and the mixture is allowed to react for a period of from 1/2 to 16 hours or more.  The reaction may also be effected by adding 10-50% by weight (based on reaction mixture) of an inert solvent or of a mineral oil diluent, or a mixture thereof.  The reaction may be moderated (a) by adding to the mixture from 1-10% by weight (based on total reactants) of a metal salt of a carboxylic acid, (b) by forming a trace of metal salt in situ by adding 0.001 to 0.1% by weight of a mineral acid, or (c) by adding to the mixture a small portion of a zinc dialkyldithiophosphate obtained from a previous batch.  The reaction may be effected at atmospheric or under reduced pressure and the products may be stablized against H2S by adding 0.1 to about 5% by weight of an alkylene oxide.  Specified metals are zinc, tin, molybdenum, antimony, cadmium, lead, chromium nickel, sodium, indium and potassium, and alcohols containing as the organic grouping alkyl, aryl, cycloaliphatic, aralkyl and heterocyclic groups may be employed.