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  Lubricating oil compositionRelated Patent Categories: Solid Anti-friction Devices, Materials Therefor, Lubricant Or Separant Compositions For Moving Solid Surfaces, And Miscellaneous Mineral Oil Compositions, Lubricants Or Separants For Moving Solid Surfaces And Miscellaneous Mineral Oil Compositions (e.g., Water Containing, Etc.), Organic Sulfur Compound, Wherein The Sulfur Is Single Bonded Directly To Oxygen (e.g., Sulfites, Etc.), The Sulfur Is Part Of An -o-s(=o)(=o)- Group (i.e., Sulfonates), Overbased Or Carbonated SulfonatesThe Patent Description & Claims data below is from USPTO Patent Application 20060014653. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to a lubricating oil composition, in particular to a lubricating oil composition which is suitable for lubricating internal combustion engines. BACKGROUND OF THE INVENTION [0002] Total Base Number (TBN) is a measure of how well a lubricating oil composition can neutralise acidic by-products of combustion/oxidation and is defined as the quantity of acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide, that is required to neutralize all basic constituents present in 1 gram of a sample of the lubricating oil composition (test methods include, for example, ISO 3771, ASTM D-2896 and ASTM D-4739). [0003] A high TBN is desirable in lubricating oil compositions in order to control corrosive engine wear from the acidic by-products of combustion/oxidation. Detergent additives in a lubricating oil composition are the primary source of alkalinity (TBN) and help to control, for example, top-ring deposits and bore polish. [0004] Hence, metal-based detergents are the primary source of TBN in crankcase lubricating oil compositions. [0005] In view of the adverse affects that the sulphated ash, sulphur and phosphorus concentrations of lubricating oil compositions may have on vehicle exhaust after-treatment devices, there is a trend towards lubricating oil compositions having reduced sulphated ash, sulphur and/or phosphorus concentrations therein (i.e. so-called low-SAPS lubricating oil compositions). [0006] Phosphorus concentrations may be generally reduced by reducing the amount of zinc dithiophosphates which are present as anti-wear additives in lubricating oil compositions. [0007] Sulphur levels in lubricating oil compositions may be reduced by employing low sulphur level base oils and reducing the amount of sulphur-containing additives employed therein. [0008] Sulphated ash is the total weight percent of residue remaining after a lubricating oil composition has been carbonised, and the residue subsequently treated with sulphuric acid and heated to constant weight. The sulphated ash content in a lubricating oil composition is related to the total metal content therein. Sulphated ash may be conveniently measured according to ASTM D874. [0009] The major sources of sulphated ash in a lubricating oil composition are generally any metal detergent additives and zinc dithiophosphate anti-wear additives that are employed therein. [0010] Hence, in current low-SAPS lubricating oil compositions, sulphated ash levels, and consequently detergent levels, are low. As a result, the starting TBN (i.e. of fresh un-used lubricating oil compositions) of low-SAPS lubricating oil compositions tends to be lower than in lubricating oil compositions having higher sulphated ash, sulphur and/or phosphorus concentrations therein. [0011] Thus, TBN retention (i.e. the ability to maintain an advantageous TBN level throughout the lifetime of a lubricating oil composition) is of increased importance for low-SAPS lubricating oil compositions which have lower starting TBNs. [0012] U.S. 2004/0102335 A1 describes lubricating oil compositions containing an additive formulation including at least one sulphonate, saligenin and salixarate detergent. However, it is apparent from the Working Examples in U.S. 2004/0102335 A1 that said lubricating oil compositions employ high TBN detergents therein. In this regard, it is of note that the Working Examples in U.S. 2004/0102335 A1 all employ a high TBN calcium sulphonate detergent therein as a TBN booster. Furthermore, U.S. 2004/0102335 A1 is concerned with the development of lubricating oil compositions with improved wear performance and is not directed to the problem of TBN retention for low-SAPs lubricating oil compositions which have lower starting TBNs. [0013] EP-A-1167497 discloses a lubricating oil composition having a sulphur content of 0.01 to 0.3 wt. % and a phosphorus content of 0.01 to 0.1 wt. %, and giving a sulphated ash content in the range of 0.1 to 1 wt. %, which is said to have good high temperature detergency, and which comprises: [0014] a) a major amount of a mineral base oil having a sulphur content of at most 0.1 wt. %; [0015] b) an ashless dispersant comprising an alkenyl- or alkyl-succinimide or a derivative thereof in an amount of 0.01 to 0.3 wt. % in terms of a nitrogen atom content; [0016] c) a metal-containing detergent containing an organic acid metal salt which is selected from the group consisting of a non-sulphurised alkali metal or alkaline earth metal salt of an alkylsalicylic acid having a TBN of 10 to 350 mg.KOH/g and a non-sulphurised alkali metal or alkaline earth metal salt of an alkylphenol derivative having a Mannich base structure, in an amount of 0.1 to 1 wt. % in terms of a sulphated ash content; [0017] d) a zinc dialkyldithiophosphate in an amount of 0.01 to 0.1 wt. % in terms of a phosphorus content; and [0018] e) an oxidation inhibitor selected from the group consisting of a phenol compound and an amine compound in an amount of 0.01 to 5 wt. %. [0019] EP-A-1167497 is in no way concerned with the problem of achieving good TBN retention, in particular with regard to the VW T4 test (PV 1449). [0020] EP-A-1104800 describes a lubricating oil composition for internal combustion engines which comprises [0021] a) a major amount of a base oil of lubricating viscosity, [0022] b) a metal-containing detergent in an amount of 0.1 to 1 wt % in terms of its sulfated ash content, [0023] c) a boron-containing alkenyl- or alkylsuccinimide in an amount of 1.0 to 15 wt % in terms of its active ingredient, [0024] d) a zinc dialkyldithiophosphate in an amount of 0.1 to 0.1 wt % in terms of its phosphorus content, [0025] e) an oxidation inhibitor in an amount of 0.1 to 5 wt % in terms of its active ingredient, and [0026] f) an ashless dithiocarbamate in an amount of 0.1 to 5 wt % in terms of its active ingredient. [0027] U.S. 2003/0148900 A1 discloses a lubricating oil composition for use in natural gas engines which comprises a minor amount of one or more specific hindered phenols and a major amount of at leats one of Group II, III and IV base oils. U.S. 2003/0148900 A1 indicates that increased amounts of antioxidants may have a detrimental effect on piston deposit control. Accordingly, U.S. 2003/0148900 A1 is directed to a method to increase the oxidation life of lubricating oil base oil without increasing the amount of antioxidant therein. However, U.S. 2003/0148900 A1 is not concerned with the problem of TBN retention for low-SAPS lubricating oil compositions which have lower starting TBNs. [0028] WO-A-03/083020 describes a method of operating an internal combustion engine that comprises introducing a nitrogen-containing detergent composition into a combustion chamber during the operation of the engine. [0029] Said detergent composition comprises [0030] (A) a reaction product of a hydrocarbyl-substituted acylating agent and an amine; [0031] (B) a hydrocarbyol-substituted amine; [0032] (C) a Mannich reaction product of a hydrocarbyl-substituted hydroxy-containing aromatic compound, an aldehyde, and an amine; [0033] (D) a high molecular weight polyetheramine prepared by reacting one unit of a hydroxy-containing hydrocarbyl compound with two or more units of butylene oxide to form apolyether intermediate, and aminating the polyether intermediate by reacting the polyether intermediate with an amine or with acrylonitrile and hydrogenating the reaction product of the polyether intermediate and acrylnitrile; or [0034] (E) a mixture thereof. [0035] U.S. Pat. No. 5,595,964 describes a method of lubricating a natural gas-fuelled internal combustion engine, comprising supplying thereto a lubricating oil composition comprising an oil of lubricating viscosity, an antioxidant, an anti-nitration agent and preferably at least about 0.1 wt. % of a borated product of an epoxide, wherein the composition is substantially free of metals and wherein the amount of the antioxidant and the anti-nitration agent are sufficient to reduce the amount of varnish formation in a natural gas-fuelled internal combustion engine. The total amount of antioxidant used in said lubricating oil composition is said to be at least 1.8 wt. %, preferably at least 2 wt. %. The lubricating oil composition of U.S. Pat. No. 5,595,964 is said to contain less than 1% sulphated ash, as determined by ASTM D874. The phosphorus level of the lubricating oil composition of U.S. Pat. No. 5,595,964 is said to preferably be less than 0.03% phosphorus, more preferably less than 0.005% phosphorus. It is of note that U.S. Pat. No. 5,595,964 is concerned with reducing varnish formation in a natural gas-fuelled internal combustion engine by the presence of an anti-nitration agent in addition to antioxidant in a lubricating oil composition. [0036] U.S. Pat. No. 5,595,964 neither identifies nor addresses the problem of poor TBN retention in lubricating oil compositions having reduced sulphated ash, sulphur and/or phosphorus concentrations therein, and in particular in low-SAPS lubricating oil compositions which have lower starting TBNs. There is no disclosure in U.S. Pat. No. 5,595,964 to suggest how to achieve good TBN retention in such lubricating oil compositions, particularly in order to pass the VW T4 test (PV 1449). SUMMARY OF THE INVENTION [0037] A lubricating oil composition is provided for internal combustion engines having a sulphated ash content of not greater than 0.9 wt. % and a phosphorus content in the range of from 0.04 to 0.1 wt. %, comprising [0038] (a) a base oil, [0039] (b) at least one detergent selected from the group consisting of phenate detergents, salicylate detergents and sulphonate detergents, wherein said detergent each, independently, have a TBN (total base number) value in the range of from 30 to 350 mg.KOH/g, as measured by ISO 3771; and [0040] (c) at least 3.5 wt. % of at least one antioxidant selected from the group consisting of aminic antioxidants, phenolic antioxidants, and mixtures thereof based on the total weight of the lubricating oil composition. Continue reading... Full patent description for Lubricating oil composition Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Lubricating oil composition patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Lubricating oil composition or other areas of interest. ### Previous Patent Application: Low-phosphorous lubricant additive Next Patent Application: Polar solvent-asphaltene dispersant method for upgrading heavy oils Industry Class: Solid anti-friction devices, materials therefor, lubricant or separant compositions for moving solid surfaces, and miscellaneous mineral oil compositions ### FreshPatents.com Support Thank you for viewing the Lubricating oil composition patent info. 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