| 摘要 |
The invention comprises mixed diesters of dithiophosphoric acid made by reacting phosphorus pentasulphide with a blend consisting of two different monohydric aliphatic alcohols, one of which contains not more than 4 carbon atoms and the other from 6 to 18 carbon atoms, and the zinc salts produced from the diesters. Many alcohols are specified for use, representative being methyl, propyl, sec.- and tert.-butyl as those of not more than 4 carbon atoms with hexyl, ethylisopropylcarbinol, 2-ethyl amyl, iso-octyl, undecyl and octadecyl as others of 6-18 carbon atoms. The mol. ratio of lower to higher alcohols in the blend may be 1 to 5 although for lubricants (see Group III) a ratio of 2 to 4 is preferred. Reaction temperatures of 120-200 DEG F. are mentioned. The zinc salts are obtained from the diesters by heating with zinc oxide. In examples, diesters are obtained by heating phosphorus pentasulphide with (1) isopropyl alcohol and methylisobutylcarbinol and (2) sec.-butyl alcohol and methylisobutylcarbinol and zinc salts prepared from each product on heating with zinc oxide.ALSO:The invention comprises an oil of lubricating viscosity containing zinc salts of mixed diesters of dithiophosphoric acid obtainable by reacting phosphorus pentasulphide with a blend consisting of two different monohydric aliphatic alcohols, one of which contains not more than 4 carbon atoms and the other from 6-18 carbon atoms. Many alcohols are specified for use, representative being methyl, propyl, sec. and tert.-butyl as those of not more than 4 carbon atoms with hexyl, ethylisopropyl carbinol, 2-ethylamyl, iso-octyl undecyl and octadecyl as others of 6-18 carbon atoms. A mol. ratio of lower to higher alcohols of 2 to 4 is preferred. The zinc salts are obtained from the diesters by treatment with zinc oxide. Lubricating oils mentioned include naphthenic and paraffin base oils, mixed base mineral oils, alkylene polymers, alkylene oxide polymers, dicarboxylic acid esters, phosphorus esters, silicate fluids and many members of these classes are specified. Preferably 0.05-2.0 per cent. by weight of additive is used but concentrates containing 50 or more per cent. may be prepared. Engine tests are given showing the anti-oxidative effect and the effect on the Inhibition Period of zinc butyl methylisobutyl carbinol dithiophosphate in mineral oils optionally containing a sulphurized alkyl-substituted calcium phenate. The zinc salts may be used in conjunction with other additives those specified being phenates, e.g. calcium cetyl phenate, sulphonates, e.g. calcium petroleum sulphonate, phenols, e.g. 2, 6-di-tertiary butyl-4-methyl phenol, phosphonates, e.g. calcium white oil phosphonate, thiophosphonates, e.g. calcium cetyl thiophosphonate and sulphur containing paraffins, e.g. sulphurized diparaffin sulphide. |
