ĐÂY LÀ BẢN ĐĂNG KÝ QUYỀN SỞ HỮU TRÍ TUỆ CÔNG NGHỆ TITAN HÓA LỎNG CỦA HÃNG DẦU NHỚT CONOCOPHILLIPS.
iều9 này tạo nên sự khác biệt về chất lượng của dầu nhớt nhãn hiệu Kendall, Conoco và Phillips 66
us 20090318318A1
(19) United states
(12) Patent Application Publication (10) Pub. No.: us 2009/0318318 AI
MATHUR et ai. (43) Pub. Date: Dec. 24,2009
(54) METHOD FOR MAKING A
TITANIUM-CONTAINING LUBRICANT ADDITIVE
(75) Inventors: Naresh c. MATHUR, Midlothian, VA (US); Jeffrey M. GUEVREMONT, Richmond, VA (US)
Correspondence Address: AFTON CHEMICAL CORPORATION LUEDEKA, NEELY & GRAHAM, PC P.O. BOX 1871
KNOXVILLE, TN 37901 (US)
(73) Assignee: AFTON CHEMICAL
CORPORATION, Richmond, VA (US)
(21) Appl.No.: 12/141,301
(22) Filed: Jun. 18, 2008
Publication Classification
(51) Int. CI.
C10M125/10 (2006.01)
(52) U.S. CI......................................................................................... 508/165
(57) ABSTRACT
A method for making a titanium-containing lubricant additive, a lubricant additive concentrate made by the method and a lubricating composition containing the additive concentrate. The method includes reacting titanium alkoxide with water in a reaction medium that includes a dispersant to provide a homogeneous titanium-containing additive product. The additive product made by the method is substantially devoid of acidic components.
METHOD FOR MAKING A TITANIUM-CONTAINING LUBRICANT ADDITIVE
TECHNICAL FIELD
[0001] The disclosure relates to titanium-containing lubricant additives that are substantially devoid of acidic components, and in particular to methods for making homogeneous titanium-containing lubricant additive concentrates that having unique tribological properties.
BACKGROUND AND SUMMARY
[0002] Lubricating oils for automotive and diesel engines have changes over the years. Today's engines are designed to run hotter and harder than in the past. Various additives have been used in lubricant formulations in order to reduce friction between moving parts and reduce engine wear. Such additives include organo-molybdenum additives and organo-zinc phosphate additives. While such additives are particularly useful as friction and wear reducers modifiers, such additives may have one or more of the following disadvantages: poor oil solubility; copper and/or lead corrosion; color darkening of the finished lubricant; and increased levels of sulfur and/or phosphorus in the finished lubricant.
[0003] Future generations of passenger car motor oils and heavy duty diesel engine oils require lower levels of phosphorus and sulfur in the finished oil in order to protect pollution control devices as it is well known that sulfur and phosphorus containing additives may poison or otherwise reduce the effectiveness of pollution control devices. For example, current GF-4 motor oil specifications require a finished oil to contain less than 0.08 wt % and 0.7 wt % phosphorus and sulfur, respectively, and PC-10 motor oil specifications, the next generation heavy duty diesel engine oil, requires oils to contain less than 0.12 wt % and 0.4 wt % phosphorus and sulfur, respectively, and 1.0 wt % sulfated ash. Certainmolyb-denum and organo-zinc additives known in the industry contain phosphorus and sulfur at levels which reduce the effectiveness of pollution control devices.
[0004] Therefore, a need exists for lubricant additives and compositions that provide enhanced friction and wear reducing properties and which are more compatible with pollution control devices used for automotive and diesel engines. A need also exists for such lubricant additives and compositions which are more compatible with such pollution control devices without adversely affecting oil solubility, corrosion, and/or darkening the color of the finished lubricant. Hydrocarbon soluble organo-titanium compounds are believed to be useful for reducing the amount of molybdenum and/or organo-zinc compounds used in lubricating oil formulations while achieving similar or improved results without adversely affecting pollution control devices on the engines. [0005] The use of organo-titanium compounds typically includes a multi-step synthesis process, purification, and blending of the compounds into additive concentrates and lubricant formulations. However, the foregoing process is time-consuming thus expensive. What is needed is a relatively simple process for making a titanium-containing additive in-situ in a concentrate that can be directly added to an oil of lubricating viscosity.
[0006] With regard to the foregoing, exemplary embodiments of the disclosure provide a method for making a titanium-containing lubricant additive, a lubricant additive concentrate made by the method and a lubricating composition containing the additive concentrate. According to embodiments of the disclosure, the method includes reacting titanium alkoxide with water in a reaction medium that includes a dispersant to provide a homogeneous titanium-containing additive product. The additive product made by the method is substantially devoid of acidic components. [0007] Another exemplary embodiment of the disclosure provides a titanium additive product for a lubricating oil. The additive product includes a titanium product made by a process of reacting titanium alkoxide with water in a reaction medium including a dispersant at a temperature ranging from about 25° to about 140° c. to provide a homogeneous titanium-containing additive product. The additive product in a base oil is no more corrosive than the base oil devoid of the additive product as determined by a high temperature corrosion bench test.
[0008] An advantage of the embodiments of the disclosure is that a substantially precipitate free product may be formed. The product is believed to be less corrosive in lubricating oil formulations since the product is not made using acidic reac-tants. Blending of the product with other components of a lubricating oil composition may be more precise due to an absence of visible particles and precipitates in the additive product as made. Other features and advantages of the disclosed embodiments may be provided by the following detailed description.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
OR I
RO—ti-I
Ó ĩ
RO — Ti-I
OR
OR ì
-o—ti — Ì
Ó
ĩ
-o—Ti — I
OR
[0009] As set forthherein, the disclosure provides an in-situ method for making a homogenous titanium-containing additive product that may have enhanced wear and friction reducing properties when used in a lubricating oil composition. The exact nature of the product made by the method is not known and has not been fully characterized despite extensive efforts to determine the exact nature of the product. Particles of product made by the disclosed process were observed using a transmission electron microscope by solvent rinsing the product. The particles appeared to range in size from about 24 nanometers (run) to about 370 run and the particles had a spherical to cylindrical shape. Accordingly, it is believed that the titanium product may include non-acidic titanium oxide nanoparticles of the formula Ti[sub]x[/sub]Oy, wherein a ratio of X to y ranges from about 1:1 to about 1:10 and wherein the titanium oxide nanoparticles are readily dispersible or dissolvable in an organic fluid. It is also possible that the titanium product may include a polytitanoxane product of the formulas:
OR ì
-o — ti------- OR
I
OR
-OR
-continued OR r OR~l OR
I I I
RO—ti o—ti o—ti OR
I I I
0 0 ó
I. I. I.
RO — Ti o—Ti o—Ti OR
1 I I OR L OR J OR
wherein R is an alkyl group containing from 1 to 10 carbon atoms and n is an integer ranging from about 1 to about 1000. It is also possible that the product is a mixture of titanium oxide nanoparticles and polytitanoxanes. [0010] For the purposes of this disclosure, a "homogeneous product" means that the titanium-containing component may be dissolved in, dispersed in, or emulsified in an organic fluid whereby discrete particles and precipitates are undetectable with the unaided human eye.
[0011] A fist step in preparing a product according to the disclosure is to heat a mixture of dispersant and optionally, process oil to room temperature or to an elevated temperature. Process oil is used to reduce the viscosity of the mixture and typically acts as a diluent. The dispersant may be selected from a wide variety of ashless dispersants, including but not limited to, compounds having an oil soluble polymeric hydrocarbon backbone having functional groups that are capable of associating with titanium-containing additive. Typically, the dispersants comprise amine, alcohol, amide, or ester polar moieties attached to the polymer backbone often via a bridging group. Dispersants may be selected from Marmich dis-persants as described, for example, in U.S. Pat. Nos. 3,697, 574 and 3,736,357; ashless succinimide dispersants as described in U.S. Pat. Nos. 4,234,435 and 4,636,322; amine dispersants as described in U.S. Pat. Nos. 3,219,666, 3,565, 804, and 5,633,326; Koch dispersants as described in U.S. Pat.Nos. 5,936,041,5,643,859,and5,627,259, andpolyalky-lene succinimide dispersants as described in U.S. Pat. Nos. 5,851,965; 5,853,434; and 5,792,729. A particularly suitable dispersant is a polyisobutenyl succinimide dispersant wherein the polyisobutenyl group has a number average molecular weight ranging from about 1000 to about 5000 and the succinimide has a total base number (TBN) ranging from about 10 to about 50. The ashless dispersant is typically provided as a mixture in process oil wherein the mixture includes from about 30 to about 60 weight percent of the dispersant with the balance being the process oil. Accordingly, the reaction medium may include from about 10 to about 60 percent by weight of the ashless dispersant and from about 40 to about 90 percent process oil. [0012] The reaction medium including the dispersant and optional process oil is then typically heated to a temperature in the range of from about 25° to about 100° c. under an inert gas atmosphere in order to reduce the viscosity of the mixture prior to adding a titanium alkoxide compound to the reaction medium. Suitable titanium alkoxide compounds may be selected from alkoxides containing from about 1 to about 10 carbon atoms such as, titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium propoxide, titanium butox-ide, titanium secondary butoxide, titanium t-butoxide, titanium hexoxide, titanium octoxide, and the like. A molar ratio of titanium alkoxide to the dispersant in the reaction medium may range from about 1:1 to about 10:1 alkoxide to dispers-ant.
[0013] The titanium alkoxide, dispersant and optional process oil provides a reaction mixture to which water is added with or without an inert solvent. The inert solvent, when used, may be any water-miscible solvent. A suitable solvent is an alkanol. The alkanol may be selected from C[sub]2[/sub] to C[sub]5[/sub] alkanols such as ethanol, propanol, isopropanol, butanol, isobutanol, tert butyl alcohol, amyl alcohol, isoamyl alcohol, diethyl carbinol, methyl (n)propyl carbinol, methyl isopropyl carbinol, dimethyl ethyl carbinol, and the like. Glyclols such as ethylene glycol and propylene glycol may also be used. When a solvent is used, the inert solverrt/water mixture may include from about 0.5 to about 1.5 moles of solvent permole of water. With respect to the titanium alkoxide component, the ratio of water to titanium alkoxide in the reaction mixture may range from about 1:1 to about 2:1. It is understood that more than about 2 moles of water per mole of titanium alkox-ide may become a solvent as the titanium alkoxide may become completely hydrolyzed to titanium dioxide. [0014] Once all of the water or alkanol/water mixture has been added to the reaction mixture, the reactants are heated to a temperature ranging from about 25° to about 140° c. for a period of time ranging from about 30 minutes to 90 minutes, and then the product is vacuum stripped to provide a substantially homogenous product that contains no readily visible particles. The product may contain from about 1 to about 5 percent titanium on a metal basis. The product may be added directly to a lubricating oil, or may be formulated with additional components to provide a lubricating oil concentrate. [0015] In the preparation of lubricating oil formulations it is common practice to introduce concentrate in the form of 1 to 99 wt. % active ingredient in a hydrocarbon oil, e.g. mineral lubricating oil, or other suitable solvent. Usually these concentrates may be added to a lubricating oil along with a dispersant/inhibitor (DI) additive package and viscosity index (VI) improvers containing 0.01 to 50 parts by weight of lubricating oil per part by weight of the DI package to form finished lubricants, e.g. crankcase motor oils. Suitable DI packages are described for example in U.S. Pat. Nos. 5,204, 012 and 6,034,040 for example. Among the types of additives included in the DI additive package are detergents, dispers-ants, antiwear agents, friction modifiers, seal swell agents, antioxidants, foam inhibitors, lubricity agents, rust inhibitors, corrosion inhibitors, demulsifiers, viscosity index improvers, and the like. Several of these components are well known to those skilled in the art and are preferably used in conventional amounts with the additives and compositions described herein.
[0016] Lubricant compositions made with the titanium-containing additives described above are used in a wide variety of applications. For compression ignition engines and spark ignition engines, it is preferred that the lubricant compositions meet or exceed published GF-4 or API-CI-4 standards. Lubricant compositions according to the foregoing GF-4 or API-CI-4 standards include a base oil, the DI additive package, and/or a VI improver to provide a fully formulated lubricant. The base oil for lubricants according to the disclosure is an oil of lubricating viscosity selected from natural lubricating oils, synthetic lubricating oils and mixtures thereof. Such base oils include those conventionally employed as crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines, such as
automobile and truck engines, marine and railroad diesel engines, and the like. Fully formulated lubricant compositions including the titanium-containing additives may have a titanium concentration ranging from about 10 to about 1000 ppm based on titanium metal. More typically, the fully formulated lubricant composition may contain from about 50 to about 500 ppm titanium on a metal basis.
Phosphorus-Containing Compounds
[0017] One component of the DI additive package is a phosphorus-containing compound such as ZDDP. Suitable ZDDPs may be prepared from specific amounts of primary and secondary alcohols. For example, the alcohols may be combined in a ratio of from about 100:0 to about 0:100 primary-to-secondary alcohols. As an even further example, the alcohols may be combined in a ratio of about 60:40 primary-to-secondary alcohols. An example of a suitable ZDDP may comprise the reaction product obtained by combining: (i) about 50 to about 100 moi % of about C[sub]1[/sub] to about C[sub]1[/sub]8 primary alcohol; (ii) up to about 50 moi % of about C[sub]3[/sub] to C[sub]18[/sub] secondary alcohol; (iii) a phosphorus-containing component; and (iv) a zinc-containing component. As a further example, the primary alcohol may be a mixture of from about Cj to about C[sub]18[/sub] alcohols. As an even further example, the primary alcohol may be a mixture of a C[sub]4[/sub] and a C8 alcohol. The secondary alcohol may also be a mixture of alcohols. As an example, the secondary alcohol may comprise a C[sub]3[/sub] alcohol. The alcohols may contain any of branched, cyclic, or straight chains. The ZDDP may comprise the combination of about 60 moi % primary alcohol and about 40 moi % secondary alcohol. In the alternative, the ZDDP may comprise 100 moi % secondary alcohols, or 100 moi % primary alcohols. [0018] The phosphorus-containing component of the phosphorus-containing compound may comprise any suitable phosphorus-containing component such as, but not limited to a phosphorus sulfide. Suitable phosphorus sulfides may include phosphorus pentasulfide or tetraphosphorus trisul-fide.
[0019] The zinc-containing component may comprise any suitable zinc-containing component such as, but not limited to zinc oxide, zinc hydroxide, zinc carbonate, zinc propylate, zinc chloride, zinc propionate, or zinc acetate. [0020] The reaction product may comprise a resulting mixture, component, or mixture of components. The reaction product may or may not include unreacted reactants, chemically bonded components, products, or polar bonded components.
[0021] The ZDDP or ash-containing phosphorus compound may be present in an amount sufficient to contribute from about 0.03 wt % to about 0.15 wt % phosphorus in the lubricant composition.
[0022] In addition to, or in the alternative, an ash-free phosphorus compound may be included in a mixture of phosphorus-containing compounds. The ash-free phosphorus compound may be selected from an organic ester of phosphoric acid, phosphorous acid, or an amine salt thereof. For example, the ash-free phosphorus-containing compound may include one or more of a dihydrocarbyl phosphite, a trihydrocarbyl phosphite, a monohydrocarbyl phosphate, a dihydrocarbyl phosphate, a trihydrocarbyl phosphate, any sulfur analogs thereof, and any amine salts thereof. As a further example, the ash-free phosphorus-containing compound may include at least one or a mixture of monohydrocarbyl- and dihydrocar-byl phosphate amine salt, for example, an amyl acid phosphate salt may be a mixture of monoamyl acid phosphate salt and diamyl acid phosphate salt.
[0023] A weight ratio based on phosphorus from the ash-containing phosphorus compound and phosphorus from the ash-free phosphorus compound in the lubricating oil composition may range from about 3:1 to about 1:3. Another mixture of phosphorus compounds that may be used may include from about 0.5 to about 2.0 parts by weight of phosphorus from an ash-containing phosphorus compound to about 1 part weight of phosphorus from an ash-free phosphorus compound. Yet another mixture of phosphorus compounds may include about equal parts by weight of phosphorus from the ash-containing phosphorus compound and phosphorus from the ash-free phosphorus compound. Examples of mixtures of phosphorus from the ash-containing and phosphorus from the ash-free phosphorus compounds are provided in the following table.
[0024] The mixture of phosphorus-containing compounds in the lubricating oil formulation may be present in an amount sufficient to provide from about 300 to about 1200 parts per million by weight of total phosphorus in the lubricating oil formulation. As a further example, the mixture of phosphorus-containing compounds may be present in an amount sufficient to provide from about 500 to about 800 parts per million by weight of total phosphorus in the lubrication oil formulation.
[0025] Representative effective amounts of additives, when used in crankcase lubricants, are listed in Table 1 below. All the values listed are stated as weight percent active ingredient.
Dispersant Components
[0026] Dispersants contained in the DI package include, but are not limited to, the dispersants described above that are used to make the titanium-containing additive component.
Oxidation Inhibitor Components
[0027] Oxidation inhibitors or antioxidants reduce the tendency of base stocks to deteriorate in service which deterioration can be evidenced by the products of oxidation such as sludge and varnish-like deposits that deposit on metal surfaces and by viscosity growth of the finished lubricant. Such oxidation inhibitors include hindered phenols, sulfurized hindered phenols, alkaline earth metal salts of alkylphenolth-ioesters having C[sub]5[/sub] to C[sub]12[/sub] alkyl side chains, sulfurized alky-lphenols, metal salts of either sulfurized or nonsulfurized
alkylphenols, for example calcium nonylphenol sulfide, ashless oil soluble phenates and sulfurized phenates, phospho-sulfurized or sulfurized hydrocarbons, phosphorus esters, metal thiocarbamates, and oil soluble copper compounds as described in U.S. Pat. No. 4,867,890.
[0028] Other antioxidants that may be used in combination with the hydrocarbon soluble titanium compounds, include sterically hindered phenols and diarylamines, alkylated phe-nothiazines, sulfurized compounds, and ashless dialky-ldithiocarbamates. Non-limiting examples of sterically hindered phenols include, but are not limited to, 2,6-di-tertiary butylphenol, 2,6 di-tertiary butyl methylphenol, 4-ethyl-2,6-di-tertiary butylphenol, 4-propyl-2,6-di-tertiary butylphenol, 4-butyl-2,6-di-tertiary butylphenol, 4-pentyl-2,6-di-tertiary butylphenol, 4-hexyl-2,6-di-tertiary butylphenol, 4-heptyl-2, 6-di-tertiary butylphenol, 4-(2-ethylhexyl)-2,6-di-tertiary butylphenol, 4-octyl-2,6-di-tertiary butylphenol, 4-nonyl-2, 6-di-tertiary butylphenol, 4-decyl-2,6-di-tertiary butylphe-nol, 4-undecyl-2,6-di-tertiary butylphenol, 4-dodecyl-2,6-di-tertiary butylphenol, methylene bridged sterically hindered phenols including but not limited to 4,4-methylenebis(6-tert-butyl-o-cresol), 4,4-methylenebis(2-tert-amyl-o-cresol), 2,2-methylenebis(4-methyl-6 tert-butylphenol, 4,4-methylene-bis(2,6-di-tert-butylphenol) and mixtures thereof as described in u.s Publication No. 2004/0266630. [0029] Diarylamine antioxidants include, but are not limited to diarylamines having the formula:
H I
R' — N—R"
wherein R' and R" each independently represents a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms. Illustrative of substituents for the aryl group include aliphatic hydrocarbon groups such as alkyl having from 1 to 30 carbon atoms, hydroxy groups, halogen radicals, carboxy-lic acid or ester groups, or nitro groups. [0030] The aryl group is preferably substituted or unsub-stituted phenyl or naphthyl, particularly wherein one or both of the aryl groups are substituted with at least one alkyl having from 4 to 30 carbon atoms, preferably from 4 to 18 carbon atoms, most preferably from 4 to 9 carbon atoms. It is preferred that one or both aryl groups be substituted, e.g. mono-alkylated diphenylamine, di-alkylated diphenylamine, or mixtures of mono- and di-alkylated diphenylamines. [0031] The diarylamines may be of a structure containing more than one nitrogen atom in the molecule. Thus the dia-rylamine may contain at least two nitrogen atoms wherein at least one nitrogen atom has two aryl groups attached thereto, e.g. as in the case of various diamines having a secondary nitrogen atom as well as two aryls on one of the nitrogen atoms.
[0032] Examples of diarylamines that may be used include,
but are not limited to: diphenylamine; various alkylated
diphenylamines; 3-hydroxydiphenylamine; N-phenyl-1,2-
phenylenediamine; N-phenyl-1,4-phenylenediamine;
monobutyldiphenyl-amine; dibutyldiphenylamine; monooc-tyldiphenylamine; dioctyldiphenylamine; monononyldiphe-nylamine; dinonyldiphenylamine; monotetradecyldipheny-lamine; ditetradecyldiphenylamine, phenyl-alpha-naphthylamine; monooctyl phenyl-alpha-naphthylamine; phenyl-beta-naphthylamine; monoheptyldiphenylamine;
diheptyl-diphenylamine; p-oriented styrenated dipheny-lamine; mixed butyloctyldi-phenylamine; and mixed octyl-styryldiphenylamine.
[0033] Another class of aminic antioxidants includes phe-nothiazine or alkylated phenothiazine having the chemical formula:
wherein Rị is a linear or branched C[sub]1[/sub] to C[sub]24[/sub] alkyl, aryl, heteroalkyl or alkylaryl group and R[sub]2[/sub] is hydrogen or a linear or branched Ci-024 alkyl, heteroalkyl, or alkylaryl group. Alkylated phenothiazine may be selected from the group consisting of monotetradecylphenothiazine, ditetradecylphe-nothiazine, monodecylphenothiazine, didecylphenothiazine, monononylphenothiazine, dinonylphenothiazine, monoctyl-phenothiazine, dioctylphenothiazine, monobutylphenothiaz-ine, dibutylphenothiazine, monostyrylphenothiazine, distyrylphenothiazine, butyloctylphenothiazine, and styry-loctylphenothiazine.
[0034] The sulfur containing antioxidants include, but are not limited to, sulfurized olefins that are characterized by the type of olefin used in their production and the final sulfur content of the antioxidant. High molecular weight olefins, i.e. those olefins having an average molecular weight of 168 to 351 g/mole, are preferred. Examples of olefins that may be used include alpha-olefins, isomerized alpha-olefins, branched olefins, cyclic olefins, and combinations of these. [0035] Alpha-olefins include, but are not limited to, any C[sub]4 [/sub]to C[sub]25[/sub] alpha-olefins. Alpha-olefins may be isomerized before the sulfurization reaction or during the sulfurization reaction. Structural and/or conformational isomers of the alpha olefin that contain internal double bonds and/or branching may also be used. For example, isobutylene is a branched olefin counterpart of the alpha-olefin 1-butene.
[0036] Sulfur sources that may be used in the sulfurization reaction of olefins include: elemental sulfur, sulfur monochloride, sulfur dichloride, sodium sulfide, sodium polysulfide, and mixtures of these added together or at different stages of the sulfurization process. [0037] Unsaturated oils, because of their unsaturation, may also be sulfurized and used as an antioxidant. Examples of oils or fats that may be used include corn oil, canola oil, cottonseed oil, grapeseed oil, olive oil, palm oil, peanut oil, coconut oil, rapeseed oil, safflower seed oil, sesame seed oil, soyabean oil, sunflower seed oil, tallow, and combinations of these.
[0038] The amount of sulfurized olefin or sulfurized fatty oil delivered to the finished lubricant is based on the sulfur content of the sulfurized olefin or fatty oil and the desired level of sulfur to be delivered to the finished lubricant. For example, a sulfurized fatty oil or olefin containing 20 weight % sulfur, when added to the finished lubricant at a 1.0 weight % treat level, will deliver 2000 ppm of sulfur to the finished lubricant. A sulfurized fatty oil or olefin containing 10 weight % sulfur, when added to the finished lubricant at a 1.0 weight % treat level, will deliver 1000 ppm sulfur to the finished
