Lubricating oil additive having improved copper corrosion properties

摘要

755,170. Phospho-sulphurized metal alkyl phenol sulphides; metal alkyl phenol sulphides. ESSO RESEARCH & ENGINEERING CO., [formerly STANDARD OIL DEVELOPMENT CO.]. Aug. 10, 1954 [Oct. 26, 1953], No. 23167/54. Class 2 (3). [Also in Groups III and V] Phospho-sulphurized metal salts of alkyl phenol sulphides are prepared by heating a sulphide of phosphorus in a mol. ratio of less than 0.25: 1.0 at 100-200‹ C. with a metal alkyl phenol sulphide containing less than 0.3 per cent by weight of water. The reaction may be conducted in a solvent such as a mineral oil or a hydrocarbon, such as xylol. The phosphorus sulphides specified are the pentasulphide (P 2 S 5 ), the trisulphide (P 4 S 3 ) or the heptasulphide (P 4 S 7 ). The metal alkyl phenol sulphide may have the general formula where R is one or more alkyl groups each containing from 5 to 25 carbon atoms such as t.- octyl- and t.-amyl-, M is a metal and x is an integer between 1 and 4. Metal alkyl phenol sulphides specified are those of alkaline-earth metals such as barium, calcium or strontium or of mixtures thereof such as calcium tert.-octyl phenol sulphide, barium-2:4-di-tert.-amyl phenol sulphide, strontium tert.-amyl phenol sulphide and the mixed calcium-barium tert.- octyl phenol sulphide. After the reaction with phosphorus sulphide, the reaction mixture is filtered and nitrogen is blown through at 100-120‹ C. to remove unwanted products and to yield a solution of the product which may be added as an antioxidant and detergent to mineral oils and motor fuels (see Group III), to natural or synthetic rubber, asphalts, road oils and waxes (see Group V), and in organic materials generally. Examples illustrate the effect on the characteristics of the product of the use of various mol. ratios of phosphorus sulphide and metal alkyl phenol sulphide and of various degrees of dryness of the metal alkyl phenol sulphide. Metal alkyl phenol sulphides.-The metal alkyl phenol sulphides are prepared by adding the corresponding metal or metallic oxide, hydroxide or sulphide at an elevated temperature to a mineral oil solution of the alkyl phenol sulphide. The solution may contain sufficient higher alcohol as an anti-foaming agent to give a concentration of 2-15 per cent of alcohol in the final metal salt concentrate. Alcohols specified are stearyl, lauryl, cetyl or wool fat alcohol or hydrogenated coconut oil alcohol. Water is removed by blowing nitrogen through the solution at a temperature above 100‹ C. until the water content is below 0.3 per cent by weight. In an example, barium hydroxide octahydrate is added to a solution of tert.-octyl phenol sulphide in higher alcohols and mineral lubricating oil at 120‹ C. until neutralized, the reaction mixture filtered and blown with nitrogen to give an oil concentrate containing 40 per cent barium tert.-octyl phenol sulphide.