Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M159/00—Lubricating compositions characterised by the additive being of unknown or incompletely defined constitution
  • C10M159/12—Reaction products
  • C10M159/20—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products
  • C10M159/22—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products containing phenol radicals
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/02—Hydroxy compounds
  • C10M2207/023—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
  • C10M2207/028—Overbased salts thereof
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/26—Overbased carboxylic acid salts
  • C10M2207/262—Overbased carboxylic acid salts derived from hydroxy substituted aromatic acids, e.g. salicylates
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/08—Thiols; Sulfides; Polysulfides; Mercaptals
  • C10M2219/082—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
  • C10M2219/087—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing hydroxy groups; Derivatives thereof, e.g. sulfurised phenols
  • C10M2219/089—Overbased salts
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
  • C10N2040/252—Diesel engines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
  • C10N2040/252—Diesel engines
  • C10N2040/253—Small diesel engines

Definitions

• This invention relates to oil-soluble overbased salicylate-phenate detergent additives, or concentrates, for lubricating oil compositions, such as compression-ignited (diesel) marine engine lubricating oil compositions.
• marine does not restrict the engines to those used in waterborne vessels; as is understood in the art, it also includes those for auxiliary power generation applications and for main propulsion stationary land-based engines for power-generation.
• One type of marine diesel engine is a medium-speed four-stroke engine, frequently referred to as a trunk piston engine.
• Lubricants or lubricating oil compositions for such engines are known and may be referred to as trunk piston engine oils or TPEO's.
• EP-A-0 662 508 describes a way of overcoming the problem using a composition that includes, as a detergent, a hydrocarbyl-substituted phenate concentrate having a TBN greater than 300 and a hydrocarbyl-substituted salicylate.
• the data in Example 2 thereof demonstrate that, for a combination of the two detergents, performance is inferior using more salicylate than phenate compared with more phenate than salicylate.
• the present invention surprisingly establishes that, when the salicylate and phenate are present in the form of a complex, superior results are achieved when more salicylate than phenate is used.
• a complex offers the advantages of superior convenience and handleability.
• the present invention is an oil-soluble overbased salicylate-phenate detergent additive comprising a complex wherein basic material of the detergent is stabilised by both salicylate and phenate surfactants, wherein the mass % of the salicylate, as a percentage of the total surfactant mass, is at least 50, preferably greater than 50, provided that, when said mass % is less than 60, the TBN: mass % surfactant ratio of the detergent is 10 or less.
• the present invention is a lubricating oil composition
• a lubricating oil composition comprising an admixture of an oil of lubricating viscosity, in a major amount, and a detergent additive of the first aspect of the invention, in a minor amount.
• the present invention is a method of lubricating a trunk piston marine diesel engine comprising supplying to the engine a lubricating oil composition of the second aspect of the invention.
• the invention is a combination comprising:
• the invention is the use of a detergent additive of the first aspect of the invention in a lubricating oil composition to suspend asphaltene components in the composition when used in a trunk piston marine diesel engine.
• the percentage of surfactant in the overbased detergent, and the percentages of the individual surfactants, for example, phenol, in the surfactant system, are the percentages measured by the method set out below, which also indicates how the "standardized TBN" of an overbased detergent is determined.
• a known amount (A g, approximately 20 g) of the liquid overbased detergent (substantially free from other lubricating oil additives) is dialysed through a membrane in a Soxhlet extractor (150 mm height x 75 mm internal diameter) using n-hexane siphoning at a rate of 3 to 4 times per hour for 20 hours.
• the membrane should be one that retains substantially all the metal-containing material, and passes substantially all the remainder of the sample.
• An example of a suitable membrane is a gum rubber membrane supplied by Carters Products, Division of Carter Wallace Inc., New York, NY 10105 under the trade name Trojans.
• the dialysate and residue obtained on completion of the dialysis step are evaporated to dryness, any remaining volatile material then being removed in a vacuum oven (100°C at less than 1 torr or less than about 130 Pa).
• the mass of the dried residue, in grams, is designated B.
• the "standardized TBN" of the overbased detergent (that is, the TBN expressed in a manner which is independent of the amount of diluent) is the TBN measured according to ASTM D2896 on the dried residue.
• a known amount (D g, approximately 10 g) of the dried residue is hydrolyzed as specified in sections 8.1 to 8.1.2 of ASTM D3712, except that at least 200 ml of 25 % by volume hydrochloric acid (sp. gr. 1.18) is used in section 8.1.1.
• the amount of hydrochloric acid used should be sufficient to effect acidification/hydrolysis of the overbased detergent residue into organic materials (surfactants) and inorganic materials (calcium-containing materials, for example, calcium chloride).
• the combined ether extracts are dried by passing them through anhydrous sodium sulphate. The sodium sulphate is rinsed with clean ether, and the combined ether solutions are evaporated to dryness (at approximately 110°C) to yield a hydrolyzed residue.
• the mass of the dried hydrolyzed residue, in grams, is designated E.
• the techniques described below isolate the individual surfactants, in hydrolyzed form, from the hydrolyzed surfactant mixture derived from the overbased detergent.
• the proportion of each individual surfactant is the proportion by mass of the individual surfactant, in hydrolyzed form, in the hydrolyzed surfactant mixture.
• the overbased detergent contains a calcium phenate/ sulphonate/salicylate surfactant system
• the proportions of the individual surfactants in the surfactant system are expressed as the proportions of phenol, sulphonic acid and salicylic acid respectively.
• the proportions of individual surfactants may be determined by the following method.
• a known amount (F g, approximately 1 g) of the dried hydrolyzed residue obtained as described above is placed at the top of a 450 x 25 mm (internal diameter) fritted glass column filled with 60-100 US mesh Florisil.
• Florisil is magnesium silicate with a CAS number of 8014-97-9.
• the column is eluted with a 250 ml portion of each of seven solvents of increasing polarity, namely, heptane, cyclohexane, toluene, ethyl ether, acetone, methanol, and, lastly, a mixture of 50 volume % chloroform, 44 volume % isopropanol, and 6 volume % ammonia solution (sp. gr. 0.88).
• Each fraction is collected, evaporated to dryness, and the resulting residue is weighed and then analyzed to determine the amount (G 1 , G 2 , G 3 ... g) and nature of the surfactant(s) contained in
• Analysis of the fractions can be carried out by, for example, chromatographic, spectroscopic, and/or titration (colour indicator or potentiometric) techniques known to those skilled in the art.
• the overbased detergent contains a sulphonate surfactant and a salicylate surfactant
• the sulphonic acid and salicylic acid obtained by hydrolysis of these surfactants will usually be eluted from the column together.
• the proportion of sulphonic acid in the mixture can be determined by the method described by Epton in Trans.Far.Soc. April 1948, 226.
• the mass (in grams, designated H1) of a given surfactant, in hydrolyzed form is determined from the fraction(s) containing it, and thus the proportion of that surfactant in the surfactant system of the original overbased detergent is H 1 F x 100 %
• the percentages (by mass) of the individual surfactants (in their free form, that is, not in the form of a salt or other derivative) based on the surfactant system can be predicted from the proportions of the surfactants used as starting materials, provided that the percentage of "reactive ingredient” is known for each of the surfactant starting materials.
• the percentage of the total surfactants (in their free form) in the liquid overbased product can then be predicted, and the TBN : % surfactant ratio can be determined. Further, the standardized TBN can be predicted, provided that the proportion of the overbased detergent material in the liquid overbased product (that is, the proportion of the liquid overbased product that is not oil or non-reactive surfactant material) is known.
• lubricating oil compositions of this invention comprise defined individual, i.e, separate, components that may or may not remain the same chemically before and after mixing.
• a detergent is an additive that reduces formation of piston deposits, for example high-temperature varnish and lacquer deposits, in engines; it has acid-neutralising properties and is capable of keeping finely divided solids in suspension. It is based on metal "soaps", that is metal salts of acidic organic compounds, sometimes referred to as surfactants.
• a detergent comprises a polar head with a long hydrophobic tail, the polar head comprises a metal salt of the acid.
• Large amounts of a metal base are included by reacting an excess of a metal compound, such as an oxide or hydroxide, with an acidic gas such as carbon dioxide to give an overbased detergent which comprises neutralised detergent as the outer layer of a metal base (e.g. carbonate) micelle.
• the overbased detergents of this invention may have a TBN of 200 or greater, or 250 or greater, or 300 or greater, such as 300 to 500, preferably 300 to 400.
• the detergent is in the form of a complex wherein the basic material is stabilised by salicylate and phenate surfactants.
• Complexes are distinguished from mixtures of separate overbased detergents, an example of such a mixture being one of an overbased salicylate detergent with an overbased phenate detergent.
• the present detergents may be made, as generally described in International Patent Application Publication Nos WO 9746643/4/5/6 and 7 (mentioned above), as hybrid complexes by neutralising a mixture of a salicylic acid and a phenol with a basic metal compound, and then overbasing. Individual basic micelles of the detergent are thus stabilised by salicylate and phenate.
• They may also be made, as generally described in EP-A-0 750 659 (also mentioned above), as a calcium salicylate/phenate complex, by carboxylating a calcium phenate and then sulfurising and overbasing the mixture of calcium salicylate and calcium phenate.
• Overbasing preferably takes place at a temperature less than 100 °C, more preferably at a temperature less than 80 °C, even more preferably at a temperature less than 60 °C, even more preferably at a temperature less than 40 °C, and most preferably at a temperature less than 35 °C.
• the mixture is preferably subjected to a 'heat-soaking' step in which the mixture is maintained, without addition of any further chemical reagents, in a selected temperature range (or at a selected temperature), which is normally equal to or higher than the temperature at which carbonation is effected, for a period before any further processing steps are carried out.
• This mixture is normally stirred during heat-soaking.
• Heat-soaking may be carried out for any suitable period of at least 30 minutes, preferably at least 45 minutes, more preferably at least 60 minutes, especially at least 90 minutes.
• Temperatures at which heat-soaking may be carried out are typically in the range of from 15 °C to just below the reflux temperature of the reaction mixture, preferably 25 °C to 60 °C; the temperature should be such that substantially no materials (for example, solvents) are removed from the system during the heat-soaking step.
• the second carbonation step advantageously being followed by a heat-soaking step.
• Basic calcium compounds for use in manufacture of the overbased detergents include calcium oxide, hydroxide, alkoxides, carboxylates and mixtures thereof.
• the mixture to be overbased by the overbasing agents should normally contain water, and may also contain one or more solvents, promoters or other substances commonly used in overbasing processes.
• Suitable solvents are benzene, alkyl-substituted benzene (for example, toluene or xylene), halogen-substituted benzenes and lower alcohols with up to 8 carbon atoms.
• Preferred solvents are toluene, methanol and mixtures thereof.
• Preferred promoters are methanol, water and mixtures thereof.
• the detergent of the invention may be an alkali or alkaline earth metal, e.g., sodium, potassium, lithium, calcium, and magnesium, detergent. Calcium is preferred.
• Surfactants for the surfactant system of the overbased metal detergent may contain at least one hydrocarbyl group, for example, as a substituent on an aromatic ring.
• hydrocarbyl as used herein means that the group concerned is primarily composed of hydrogen and carbon atoms and is bonded to the remainder of the molecule via a carbon atom, but does not exclude the presence of other atoms or groups in a proportion insufficient to detract from the substantially hydrocarbon characteristics of the group.
• hydrocarbyl groups in surfactants for use in accordance with the invention are aliphatic groups, preferably alkyl or alkylene groups, especially alkyl groups, which may be linear or branched. The total number of carbon atoms in the surfactants should be at least sufficient to impart the desired oil-solubility.
• Salicylates of the invention may be non-sulphurized or sulphurized, and may be chemically modified and/or contain additional substituents, for example, as discussed below for phenates. Processes similar to those described below may also be used for sulphurizing a hydrocarbyl-substituted salicylic acid, and are known to those skilled in the art. Salicylic acids are typically prepared by the carboxylation, by the Kolbe-Schmitt process, of phenoxides, and in that case, will generally be obtained (normally in a diluent) in admixture with uncarboxylated phenol.
• Preferred substituents in salicylates are those represented by R in the description of phenols below.
• the alkyl groups advantageously contain 5 to 100 carbon atoms, preferably 9 to 30 carbon atoms, especially 14 to 20 carbon atoms.
• Phenates of the invention may be non-sulphurized or, preferably, sulphurized. Further, the term includes phenates derived from phenols containing more than one hydroxyl group (for example, alkyl catechols) or fused aromatic rings (for example, alkyl naphthols) and phenols which have been modified by chemical reaction, for example, alkylene-bridged phenols and Mannich base-condensed phenols; and saligenin-type phenols (produced by the reaction of a phenol and an aldehyde under basic conditions).
• phenols containing more than one hydroxyl group for example, alkyl catechols
• fused aromatic rings for example, alkyl naphthols
• phenols which have been modified by chemical reaction for example, alkylene-bridged phenols and Mannich base-condensed phenols
• saligenin-type phenols produced by the reaction of a phenol and an aldehyde under basic conditions.
• Preferred phenates are those derived from phenols of the formula where R represents a hydrocarbyl group and y represents 1 to 4. Where y is greater than 1, the hydrocarbyl groups may be the same or different.
• Sulphurized hydrocarbyl phenols may typically be represented by the formula: where x is generally from 1 to 4. In some cases, more than two phenol molecules may be linked by S x bridges.
• hydrocarbyl groups represented by R are advantageously alkyl groups, which advantageously contain 5 to 100 carbon atoms, preferably 5 to 40 carbon atoms, especially 9 to 12 carbon atoms, the average number of carbon atoms in all of the R groups being at least about 9 in order to ensure adequate solubility in oil.
• Preferred alkyl groups are nonyl (tripropylene) groups.
• hydrocarbyl-substituted phenols will for convenience be referred to as alkyl phenols.
• a sulphurizing agent for use in preparing a sulphurized phenol or phenate may be any compound or element which introduces -(S) x - bridging groups between the alkyl phenol monomer groups, wherein x is generally from 1 to about 4.
• the reaction may be conducted with elemental sulphur or a halide thereof, for example, sulphur dichloride or, more preferably, sulphur monochloride. If elemental sulphur is used, the sulphurization reaction may be effected by heating the alkyl phenol compound at from 50 to 250°C, and preferably at least 100°C.
• the sulphurization reaction may be effected by treating the alkyl phenol at from -10°C to 120°C, preferably at least 60°C.
• the reaction may be conducted in the presence of a suitable diluent.
• the diluent advantageously comprises a substantially inert organic diluent, for example mineral oil or an alkane.
• the reaction is conducted for a period of time sufficient to effect substantial reaction. It is generally preferred to employ from 0.1 to 5 moles of the alkyl phenol material per equivalent of sulphurizing agent.
• a basic catalyst for example, sodium hydroxide or an organic amine, preferably a heterocyclic amine (e.g., morpholine).
• the salicylate-phenate may be non-sulfurised.
• the TBN: mass % surfactant ratio is preferably 10 or less when the mass % of salicylate in the detergent is 60 or greater.
• International Publication Number WO 97/46645 describes how the TBN: mass % surfactant ratio may be measured.
• the mass % of the salicylate is 65 or greater, preferably 70 or greater, or more preferably 75 or greater.
• the salicylate surfactant content of the detergent is greater than 30, such as greater than 35, mass %, and that the phenate surfactant content of the detergent is greater than 8, such as 10 or greater, mass %.
• the detergents of the invention have a kinematic viscosity, at 100°C, of less than 1,000 mm 2 s -1, preferably between 50 and 1,000 mm 2 s -1 , more preferably between 100 and 500 mm 2 s -1 .
• the overbased detergents may be incorporated into an oil of lubricating viscosity (or basestock) in any convenient way.
• they may be added directly to the oil by dispersing or dissolving them in the oil at the desired concentration optimally with the aid of a suitable solvent such as toluene or cyclohexane, and at ambient or elevated temperature.
• the detergents of the invention posses both high TBN and high active matter content, it is possible to blend lubricating oil compositions that have relatively high TBN and organic carboxylate surfactant concentrations, at lower detergent treat rates than hitherto.
• the composition is a marine lubricant such as a TPEO.
• the lubricating oil compositions of this invention have been found to be particularly efficacious in mitigating aforementioned "black paint" problem.
• the base stock for the composition may be synthetic or natural.
• Synthetic base stocks include alkyl esters of dicarboxylic acids, polyglycols and alcohols; poly- ⁇ -olefins, including polybutenes; alkyl benzenes; organic esters of phosphoric acids; and polysilicone oils.
• Natural base stocks include mineral lubricating oils which may vary widely as to their crude source, for example, as to whether they are paraffinic, napthenic, mixed, or paraffinic-napthenic, as well as to the method used in their production, for example, their distillation range and where they are straight run or cracked, hydrofined, or solvent extracted.
• Lubricating oil base stocks suitable for use in crankcase lubricants conveniently have a viscosity of 2.5 to 12 mm 2 /s, at 100°C, although base stocks with other viscosities may also be used, for example, bright stock.
• Lubricating oil base stocks suitable for use in marine lubricants conveniently have a viscosity of typically 3 to 15 mm 2 /s, at 100°C, although base stocks with other viscosities may also be used.
• base stocks with other viscosities may also be used.
• bright stocks which typically have a viscosity of 30 to 35 mm 2 /s at 100°C may be used.
• Additional additives may be incorporated in the composition to enable it to meet particular requirements.
• additional additives which may be included in lubricating oil compositions containing an overbased detergent in accordance with the invention are viscosity index improvers, corrosion inhibitors, oxidation inhibitors or antioxidants, friction modifiers, dispersants, other detergents, metal rust inhibitors, anti-wear agents, pour point depressants, and anti-foaming agents.
• Lubricating oils suitable for use in marine engines advantageously include a dispersant and an antiwear agent as additional antioxidants, antifoaming agents and/or rust inhibitors. Certain of the additional additives specified below are more appropriate for use in lubricants for automobile engine than for use in lubricants for marine engines.
• compositions may typically contain 5 to 40 mass % of additives, the remainder being base oil.
• the temperature of the mixture was reduced to approximately 28°C, and maintained at this temperature while carbon dioxide (44g) was injected into the mixture over a period of 90-120 minutes. The temperature was then raised to 60°C over 60 minutes, following which the mixture was cooled to a temperature of approximately 28°C over 30 minutes. At 28°C, a further quantity of calcium hydroxide (88g) was added and then the temperature was maintained at approximately 28°C while carbon dioxide (44g) was again injected into the mixture over a period of 90-120 minutes. After this second carbonation step, the temperature was raised to 60°C over 90 minutes. During this heat treatment period, when the temperature reached 45°C, a further charge of diluent oil (41 g) was added.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

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• 2002
  • 2002-01-28 EP EP02075506A patent/EP1236792B1/de not_active Expired - Lifetime

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