Lubricant base oils and lubricant compositions and method for making them

Abstract

A liquid lubricant base oil composition comprising (i) a base stock comprising at least 95% by weight saturated hydrocarbons such as for example a Group II base stock, a Group III base stock and/or a base stock derived from Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon material and (ii) 0.2 to 30% by weight of an aromatic extract which has a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight % may be made by blending the components together and may be used with one or more additives in a lubricant composition which may be used in applications such as marine engine lubricants.

1 - 12 . (canceled) 
     
     
         13 . A liquid lubricant base oil composition comprising (i) a base stock comprising at least 95% by weight saturated hydrocarbons and (ii) 0.2 to 30% by weight of an aromatic extract, in which the aromatic extract has an aromatics content of 60 to 85% by weight and a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight %. 
     
     
         14 . A liquid lubricant base oil composition as claimed in  claim 13  which comprises 0.2 to 18% by weight of said aromatic extract. 
     
     
         15 . A liquid lubricant base oil composition as claimed in  claim 14  which comprises 1 to 18% by weight of said aromatic extract. 
     
     
         16 . A liquid lubricant base oil composition as claimed in  claim 13  which comprises 1 to 30% by weight of said aromatic extract. 
     
     
         17 . A liquid composition as claimed in  claim 13  in which the aromatic extract is a residual aromatic extract. 
     
     
         18 . A liquid composition as claimed in  claim 13  in which the aromatic extract is a distillate aromatic extract. 
     
     
         19 . A liquid composition as claimed in  claim 18  in which the aromatic extract is a treated distillate aromatic extract which is a distillate aromatic extract which has been subjected to at least one further treatment. 
     
     
         20 . A liquid composition as claimed in  claim 19  in which the at least one further treatment is selected from the group consisting of hydrogenation, hydrodesulphurisation, clay treatment, acid treatment and further solvent extraction. 
     
     
         21 . A liquid lubricant base oil composition as claimed in  claim 13  in which the base stock comprising at least 95% by weight saturated hydrocarbons comprises a hydroprocessed base stock and/or a base stock derived from Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon material. 
     
     
         22 . A liquid lubricant base oil composition as claimed in  claim 21  in which the hydroprocessed base stock is a Group II base stock and/or a Group III base stock. 
     
     
         23 . A liquid lubricant base oil composition as claimed in  claim 13  in which the base stock comprises a Group II base stock and/or a Group III base stock. 
     
     
         24 . A liquid composition as claimed in  claim 13  in which the base stock comprises at least one polyalphaolefin. 
     
     
         25 . A method of making a liquid lubricant base oil composition as claimed  claim 13  which method comprises blending a base stock comprising at least 95% by weight saturated hydrocarbons with sufficient aromatic extract which has an aromatics content of 60 to 85% by weight and a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight % to make a liquid lubricant base oil composition as claimed in  claim 13 . 
     
     
         26 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 13  and one or more additives. 
     
     
         27 . A liquid lubricant composition as claimed in  claim 26  in which the one or more additives are selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         28 . A liquid lubricant composition as claimed in  claim 27  when used as a 2-stroke marine diesel engine cylinder oil, 2-stroke marine diesel engine system oil or 4-stroke marine diesel engine crankcase lubricant composition. 
     
     
         29 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 19  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         30 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 18  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         31 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 19  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         32 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 20  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         33 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 21  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         34 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 22  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         35 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 23  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         36 . A liquid lubricant composition comprising a liquid lubricant base oil composition as claimed in  claim 24  and one or more additives selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers. 
     
     
         37 . The use of 0.2 to 30% by weight of an aromatic extract which has an aromatics content of 60 to 85% by weight and a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight % in a liquid lubricant base oil composition which base oil comprises a base stock comprising at least 95% by weight saturated hydrocarbons, to mitigate at least one of the deficiencies of the base stock selected from the group consisting of poor dispersancy, poor seal swell performance, poor solubility of additives and low compatibility with fuel oil in marine engine applications. 
     
     
         38 . The use as claimed in  claim 37  in which the lubricant base oil composition is a liquid lubricant base oil composition comprising (i) a base stock comprising at least 95% by weight saturated hydrocarbons and (ii) 0.2 to 30% by weight of an aromatic extract, in which the aromatic extract has an aromatics content of 60 to 85% by weight and a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight %. 
     
     
         39 . The use as claimed in  claim 37  in a liquid lubricant composition in which the lubricant base oil composition is a liquid lubricant base oil composition comprising (i) a base stock comprising at least 95% by weight saturated hydrocarbons and (ii) 0.2 to 30% by weight of an aromatic extract, in which the aromatic extract has an aromatics content of 60 to 85% by weight and a dimethyl sulphoxide extractable polycyclic aromatics content of less than 3 weight %. 
     
     
         40 . The use as claimed in  claim 25  in a liquid lubricant composition in which the one or more additives are selected from the group consisting of detergents, dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point depressants, friction modifiers, tackifiers and viscosity index improvers.