JP2015500393A - Diesel engine oil - Google Patents

Abstract

Comprising a first carboxylate detergent having from about 200 to about 400 active TBN, a second carboxylate detergent having from about 60 to about 200 active TBN, and at least one polyalkenyl succinimide Lubricating oil additive composition.

Description

  The present invention relates to a lubricating oil composition. More particularly, the present invention relates to a lubricating oil composition for use in railway diesel engines or inland ship engines.

  Corrosion of locomotive engine lead bearings has been a concern of original equipment manufacturers (OEMs). Maintaining the total base number (TBN) was also a technical issue. Railway engine oil (RREO) has historically been a non-zinc-containing formulation because silver locomotives have been used in some locomotive engines. Without taking advantage of the zinc dialkyldithiophosphate, a suitable detergent mixture was an important factor in TBN retention and lead corrosion.

  In March 2008, the Environmental Protection Agency (EPA) finalized a three-part program that drastically reduces emissions from diesel locomotives of all types—long-distance transportation, switches and passenger railways. The rules attempt to reduce 90 percent of particulate matter (PM) emissions from these engines and 80 percent of NOx emissions when fully implemented. This final rule sets new emission standards for locomotives when remanufacturing existing locomotives. The rules also impose Stage 3 emission standards for new locomotives, clean switch locomotive regulations, and idle reduction requirements for new and remanufactured locomotives. Finally, the rule establishes a long-term stage 4 standard for new engines based on the application of high-efficiency catalytic aftertreatment technology, which begins in 2015.

  A shift to low SAPS railroad engine oil is planned due to new EPA emission requirements and the introduction of ultra-low sulfur diesel (ULSD) fuel. Like heavy-duty diesel oil for truck engines, there will be a reduction in TBN and sulfur concentration. Traditionally, RREOs were 13-17 TBN oil. These changes will reduce the TBN to 8-11 TBN. Along with the longstanding interest in TBN retention and lead corrosion, the harmonious reduction of TBN and sulfur will require different formulations. When the TBN level decreased and the components could not be changed, it was found that the TBN retention and lead corrosion levels were poor. There are challenges in maintaining or improving lead corrosion and TBN retention when the oil TBN and sulfur are reduced in RREOs.

  It has been discovered that formulations containing salicylate detergents in addition to conventional ingredients showed reduced lead decay levels and better TBN retention.

Prior Art Research Disclosure Magazine No. RD0493012 teaches the use of salicylate detergents and supplemental antioxidants for improved lead corrosion in low sulfate ash, phosphorus and sulfur heavy vehicle diesel formulations.

  Japanese Patent No. 3925978 issued by Tomomi et al. Describes a lubricant base oil, (a) an overbased alkaline earth metal salicylate, (b) an overbased alkaline earth metal phenate, and (c) a bis type alkenyl succinimide, a bis type. Compositions comprising alkyl succinimides or their boron adducts are taught.

  Rocke European Patent No. 1256619 includes (A) a major amount of oil of lubricating viscosity, and added thereto (B) one or more metal detergents including a small amount of a metal salt of an organic acid. A detergent composition, wherein the metal detergent comprises more than 50 mol% of aromatic carboxylic acid metal salt per mole of organic acid metal salt of the detergent composition, and (C ) A lubricating oil composition containing a small amount of one or more co-additives, wherein phosphorus and sulfur derived from (B) or (C) or (B) and (C) per mass of said oil composition Teaches a lubricating oil composition wherein the total amount of is less than 0.1% by weight phosphorus, less than 0.5% by weight sulfur.

  Shaw US Patent Application Publication No. 2006/0052254 describes an oil containing salicylate having a sulfur content of 0.3 wt% or less, phosphorus 0.08 wt% or less, and sulfate ash content 0.80 wt% or less. Composition comprising an oil of lubricating viscosity (a) and an overbased alkali or alkaline earth metal alkyl salicylate lubricating oil detergent (b) having a salicylate soap of 20-25% by weight Teaches.

  Reiff, US Pat. No. 2197832 teaches a mineral oil composition incorporating a minor amount of a multifunctional compound selected from the group of metal organic compound classes referred to as oil-meltable or oil-mixable metal salts of alkyl-substituted hydroxyaromatic carboxylic acids. ing.

  Yagishita, U.S. Pat. 7563751 teaches a lubricating oil composition comprising a base oil having a sulfur content adjusted to 0.1% by weight and at least one of two different alkali or alkaline earth metal salicylate mixtures.

  Yasushi, JP 2007-217607, discloses mineral and / or synthetic oils as base oils, 1-8 wt% salicylate based cleaning agents, and 0.005-0.03 mass as additives. Teaches diesel engine oils containing 1% diphenylamine derivative.

One aspect of the present invention is:
a. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
b. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and c. The present invention relates to a lubricating oil additive composition comprising at least one polyalkenyl succinimide.

One aspect of the present invention is:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. The present invention relates to a lubricating oil composition comprising at least one polyalkenyl succinimide.

One aspect of the present invention is a method of operating a diesel locomotive engine comprising the step of lubricating the diesel locomotive engine with a lubricating oil composition, wherein the lubricating oil composition comprises:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. Including at least one polyalkenyl succinimide,
It relates to said method.

One aspect of the present invention is a method for operating an inland marine engine comprising the step of lubricating the inland marine engine with a lubricating oil composition, the lubricating oil composition comprising:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. Including at least one polyalkenyl succinimide,
It relates to said method.

One aspect of the present invention is a method for improving TBN retention comprising lubricating an engine with a lubricating oil composition, wherein the lubricating oil composition comprises:
1. A major amount of oil of lubricating viscosity;
2. A first carboxylate detergent having an active TBN of greater than about 200 to 400;
3. 3. a second carboxylate detergent having greater than about 60 to about 200 active TBN; and Having at least one polyalkenyl succinimide,
It relates to said method.

DETAILED DESCRIPTION OF THE INVENTION Definitions The term “alkaline earth metal” refers to calcium, barium, magnesium, strontium, and mixtures thereof.

  The term “alkyl” refers to both straight and branched chain alkyl groups.

  The term “metal” refers to an alkali metal, alkaline earth metal, transition metal, or mixtures thereof.

  The term “metal to substrate ratio (metal ratio to substrate)” refers to the ratio of the total valence of the metal to the valence of the substrate. Overbased sulfonate detergents are generally 12.5: 1 to 40: 1, 13.5: 1 to 40: 1 on one side, 14.5: 1 to 40: 1 on another side, and further And a metal ratio of 16.5: 1 to 40: 1 as a further aspect.

  The total base number (TBN or BN) number reflects more alkali product and therefore greater alkali accumulation. The sample TBN is ASTM test no. It can be determined by D2896 or other similar procedures. In general terms, TBN is the neutralizing capacity of 1 gram of a lubricating composition expressed as a number equal to milligrams of potassium hydroxide that provides valence neutralization. Thus, a TBN of 10 means that 1 gram of composition has the same neutralizing capacity as 10 mg of potassium hydroxide. The TBN of the actives should be measured.

  The term “low overbasing” or “LOB” refers to an overbased detergent having an active low TBN of about 0 to about 60.

  The term “medium overbased” or “MOB” refers to an overbased detergent having a medium TBN of greater than about 60 to about 200 actives.

  The term “highly overbased” or “HOB” refers to an overbased detergent having an active high TBN of greater than about 200 to about 400.

Lubricating oil additive composition The lubricating oil additive composition of the present invention comprises a first carboxylate detergent having a TBN of about 60 to about 200; a second carboxylate detergent having a TBN of about 200 to about 400, and Includes polyalkenyl succinimide. Other additives can be employed in the lubricating oil additive composition.

Carboxylate Detergent In one embodiment, a first carboxylate detergent and a second carboxylate detergent are used in the lubricating oil additive composition.

  Typically, the carboxylate detergent is prepared according to methods well known in the art, including, but not limited to, the processes described in US Patent Application Publication No. 2007/0105730 and US Patent Application Publication No. 2007/0027043. Is done.

  In one embodiment, the first carboxylate detergent is a single cyclic carboxylate.

Monocyclic Carboxylate One of the carboxylate detergents that can be used in the lubricating oil additive composition is a monocyclic carboxylate having a total base number (TBN) of from about 60 to about 200 actives. is there.

A single carboxylate has the following structure:

  In the formula, R is a linear hydrocarbyl group, a branched hydrocarbyl group, or a mixture thereof. Preferably R is a linear hydrocarbyl group. More preferably, R is an alkyl group having 12 to 40 carbon atoms.

  Monocyclic carboxylates are prepared according to the following method.

In the first step, the hydrocarbyl phenol is neutralized in the presence of an accelerator. In one embodiment, the hydrocarbyl phenol is neutralized using an alkaline earth metal base in the presence of at least one C ₁ to C ₄ carboxylic acid. Preferably, this reaction is carried out in the absence of alkali salts and in the absence of dialcohols or monoalcohols.

  The hydrocarbyl phenol can contain up to 100% linear hydrocarbyl groups, up to 100% branched hydrocarbyl groups, or linear and branched hydrocarbyl groups. Preferably, if present, the straight chain hydrocarbyl group is alkyl, and the straight chain alkyl group contains 12 to 40 carbon atoms, more preferably 18 to 30 carbon atoms. If present, the branched hydrocarbyl group is preferably alkyl and contains at least 9 carbon atoms, preferably 9 to 24 carbon atoms, more preferably 10 to 15 carbon atoms. In one embodiment, the hydrocarbyl phenol contains no more than 85% linear hydrocarbyl phenol (preferably at least 35% linear hydrocarbyl phenol) together with at least 15% branched hydrocarbyl phenol in the mixture.

  The use of alkylphenols containing at least 35% long chain linear alkylphenols (18 to 30 carbon atoms) is particularly attractive. This is because the long linear alkyl chain promotes the compatibility and solubility of the lubricating oil additive. However, the presence of relatively heavy linear alkyl groups in alkylphenols can make the latter more inert than branched alkylphenols. Therefore, it is necessary to use a more severe reaction to effect neutralization with the alkaline earth metal base.

  Branched alkylphenols can be obtained by reaction of phenol with a branched olefin, and usually the branched olefin is derived from propylene. They consist of a mixture of mono-substituted isomers, most of which are para-substituted, very slightly ortho-substituted, and almost no meta-substituted. This makes them relatively more reactive towards alkaline earth metal bases. The reason is that the phenol functionality is actually free of steric hindrance.

  On the one hand, linear alkylphenols can be obtained by reaction of phenol with linear olefins, usually linear olefins derived from ethylene. They are a mixture of mono-substituted isomers, and the proportion of linear alkyl substitution at the ortho, para and meta positions is more uniformly distributed. This makes them less reactive towards alkaline earth metal bases. The reason is that the phenol functionality is less accessible because of the greater steric hindrance due to the presence of the heavier alkyl substituents. Of course, straight chain alkylphenols can contain some branched chain alkyl substituents that increase the amount of para substituents and, consequently, increase the relative reactivity to alkaline earth metal bases. .

  Alkaline earth metal salts which can be used to carry out this step are calcium, magnesium, barium or strontium oxides or hydroxides, and in particular calcium oxide, calcium hydroxide, magnesium oxide and mixtures thereof It is. In one embodiment, slaked lime (calcium hydroxide) is preferred.

The accelerator used in this step can be any material that enhances neutralization. For example, the accelerator may be a polyhydric alcohol, dialcohol, monoalcohol, ethylene glycol or any carboxylic acid. Preferably carboxylic acids are used. More preferably, C ₁ to C ₄ carboxylic acids are used in this step, such as formic acid, acetic acid, propionic acid and butyric acid, which can be used alone or in admixture. Preferably, a mixture of acids is used, most preferably a formic acid / acetic acid mixture. The formic acid / acetic acid molar ratio should be between 0.2: 1 and 100: 1, preferably between 0.5: 1 and 4: 1 and most preferably 1: 1. Carboxylic acid acts as a transfer agent that aids the transfer of alkaline earth metal bases from mineral reagents to organic reagents.

  The neutralization operation is performed at a temperature of at least 200 ° C, preferably at least 215 ° C, and more preferably at least 240 ° C. The pressure is gradually reduced below atmospheric pressure to distill and remove the water of reaction. Therefore, neutralization must be performed without a solvent capable of forming an azeotrope with water. Preferably, the pressure is reduced below 7,000 Pa (70 mbars).

  The amount of reagent used should correspond to the following molar ratios: (1) Alkaline earth from 0.2: 1 to 0.7: 1, preferably 0.3: 1 to 0.5: 1 Metal base / hydrocarbylphenol and (2) 0.01: 1 to 0.5: 1, preferably 0.03: 1 to 0.15: 1 carboxylic acid / hydrocarbylphenol.

Preferably, at the end of the neutralization step, the resulting hydrocarbyl phenate is in excess of 15 hours at a temperature of at least 215 ° C. and an absolute pressure between 5,000 and 10 ⁵ Pa (0.05 and 1.0 bar). Hold for no period. More preferably, at the end of the neutralization step, the resulting hydrocarbyl phenate is held at an absolute pressure between 10,000 and 20,000 Pa (0.1 and 0.2 bar) for 2 to 6 hours. .

  By providing that the operation is carried out at a sufficiently high temperature and that the pressure in the reactor is gradually reduced to atmospheric pressure, the neutralization reaction causes the azeotrope and water to form during the reaction. This is done without the need to add the solvent that forms.

B. Carboxylation step The carboxylation step is carried out by simply bubbling carbon dioxide into the reaction medium generated from the neutralization step being processed, so that at least 20 mol% of the starting hydrocarbylphenol is hydrocarbyl salicylate (salicylic acid by potentiometric determination). Until measured). In order to avoid decarboxylation of the alkyl salicylate that forms, it must be carried out under pressure.

Preferably, at least 22 mol% of the starting hydrocarbylphenol is at a temperature between 180 ° C. and 240 ° C. under a pressure in the range from above atmospheric pressure to 15 × 10 ⁵ Pa (15 bar) for a period of 1 to 8 hours. , Converted to hydrocarbyl salicylate by using carbon dioxide.

According to one variant, at least 25 mol% of the starting hydrocarbylphenol is hydrocarbyl by using carbon dioxide at a temperature equal to or greater than 200 ° C. under a pressure of 4 × 10 ⁵ Pa (4 bar). Converted to salicylate.

C. Filtration step The product of the carboxylation step can advantageously be filtered. The purpose of the filtration process is to remove precipitates and especially crystalline calcium carbonate. And they may have been formed during the previous process and may block the filter attached to the lubricating oil circuit.

D. Separation process At least 10% of the starting hydrocarbylphenol is separated from the product of the carboxylation process. Preferably, the separation is achieved using distillation. More preferably, the distillation is at a temperature of about 150 ° C. to about 250 ° C., a pressure of about 0.1 to about 4 mbar, more preferably a temperature of about 190 ° C. to about 230 ° C., about 0.5 to about 3 mbar. The pressure is most preferably carried out in a thin film evaporator at a temperature of about 195 ° C. to about 225 ° C. and a pressure of about 1 to about 2 mbar. At least 10% of the starting hydrocarbyl phenol is separated. More preferably, at least 30% of the starting hydrocarbyl phenol is separated. Most preferably, more than 55% of the starting hydrocarbyl phenol is separated. The separated hydrocarbylphenol can then be reused so that it can be used as a starting material in a new process or in any other process.

Non-sulfurized carboxylate-containing additive The non-sulfurized carboxylate-containing additive formed in this process has more alkaline earth metal single aromatic ring hydrocarbyl salicylates and than those produced by other routes. It can be characterized by its only composition with less hydrocarbyl phenol. When the hydrocarbyl group is an alkyl group, the non-sulfurized carboxylate-containing additive has the following composition: (a) less than 40% alkylphenol, (b) 10% to 50% alkaline earth metal alkylphenate, and (b) 15% to 60% alkaline earth metal single aromatic ring alkyl salicylate.

  Unlike alkaline earth metal alkyl salicylates produced by other methods, this non-sulfurized carboxylate-containing additive composition can be used in small amounts of alkaline earth metal double aromatic ring alkyl salicylates (an alkali earth earth). It can be characterized by having metal double-aromatic-ring alkylsalicylates). The molar ratio of single aromatic ring alkyl salicylate to double aromatic ring alkyl salicylate (molar ratio of single aromatic ring alkyl salicylate to double aromatic ring alkyl salicylate) is at least 8 : 1.

Product Characterization by Infrared Spectroscopy The aromatic ring-out-of-plane C—H bending vibration was used to characterize the non-sulfurized carboxylate-containing additive of the present invention. The infrared spectrum of the aromatic ring shows a strong out-of-plane C—H variable transmission band in the range of 675-870 cm ⁻¹ . The exact frequency depends on the number and position of substituents. For ortho disubstituted compounds, a transmission band occurs at 735-770 cm ⁻¹ . For para-disubstituted compounds, a transmission band occurs at 810-840 cm ⁻¹ .

Infrared spectra of reference chemical structures corresponding to the present invention, out-of-plane C-H bending transmittance bands 750 ± ^{3 cm -1} for ortho alkylphenols, for salicylic acid, 760 ± ^{2 cm -1,} for para alkylphenol , 832 ± 3 cm ⁻¹ .

Alkaline earth alkylphenates well known in the art have infrared out-of-plane C—H variable transmission bands at 750 ± 3 cm ⁻¹ and 832 ± 3 cm ⁻¹ . Alkaline earth alkyl salicylates known in the art are 763 ± 3 cm ⁻¹ , 832 ± 3 cm ⁻¹ and have infrared out-of-plane C—H variable transmission bands.

Even when there is other evidence that an alkyl salicylate is present, the non-sulfurized carboxylate-containing additive of the present invention exhibits substantially out-of-plane C—H bending vibration at 763 ± 3 cm ^−1. Absent. This particular feature has not been fully explained. However, it can be hypothesized that the special structure of a single aromatic ring alkyl salicylate prevents this out-of-plane CH bending vibration in some way. In this structure, the carboxylic acid functionality is engaged in a cyclic structure and can therefore generate increased steric hindrance near the aromatic ring, limiting the free movement of adjacent hydrogen atoms. The hypothesis is that the infrared spectrum of the acidic product (the carboxylic acid functionality is no longer engaged in the ring structure and can therefore be rotated) has an out-of-plane C—H transmission band of 763 ± 3 cm ⁻¹ . It is supported by the fact that.

The non-sulfurized carboxylate-containing additive of the present invention is less than 0.1: 1, about 763 ± 3 cm ⁻¹ out-of-plane C—H curve vs. 832 ± 3 cm ⁻¹ out-of-plane C—H curve red. Characterized by having an outer transmission band ratio (ratio of infrared transmission band of out-of-plane C—H deflection of about 763 ± 3 cm ⁻¹ to out-of-plane C—H deflection of 832 ± 3 cm ⁻¹ ).

  This method, i.e., non-sulfurized carboxylate-containing additive formed by non-sulfurization, will provide improved high temperature precipitate control capability for the sulfurized product. By not using alkali metals, this additive can be employed as a detergent dispersion in applications such as marine engine oils where the presence of alkali metals has been found to have a detrimental effect.

Additional Carboxylate Additive The second carboxylate detergent can be prepared according to the following process.

The overbased alkaline earth metal alkylhydroxybenzoates (ie, carboxylate detergents) of the present invention will generally have a structure as shown below as Formula (I).

  In the formula, R is a linear aliphatic group, a branched aliphatic group, or a mixture of linear and branched aliphatic groups. Preferably R is an alkyl or alkenyl group. More preferably, R is an alkyl group.

  M is an alkaline earth metal selected from the group consisting of calcium, barium, magnesium and strontium. Calcium and magnesium are suitable alkaline earth metals. Calcium is more preferred.

  When R is a linear aliphatic group, the linear alkyl group typically contains about 12 to 40 carbon atoms, more preferably about 18 to 30 carbon atoms.

  When R is a branched aliphatic group, the branched alkyl group typically has at least 9 carbon atoms, preferably about 9 to 40 carbon atoms, more preferably about 9 to 24 carbon atoms, and most preferably About 10 to 18 carbon atoms. Such branched aliphatic groups are preferably derived from propylene or butene oligomers.

  R can also represent a mixture of straight or branched aliphatic groups. Preferably, R represents a mixture of linear alkyl containing about 20 to 30 carbon atoms and branched alkyl containing about 12 carbon atoms.

When R represents a mixture of aliphatic groups, the alkaline earth metal alkylhydroxybenzoic acid employed in the present invention contains a mixture of linear groups, a mixture of branched groups, or a mixture of linear and branched groups can do. Thus, R represents a linear aliphatic group, preferably alkyl, _{e.g., C 14 -C 16, C 16} -C 18, C 18 -C 20, C 20 -C 22, C 20 -C 24 and C ₂₀ -C ₂₈ alkyl and may be the alkyl group derived from an alkyl group and normal alpha olefin is selected from the group consisting of a mixture thereof. Advantageously, these mixtures are at least 95 mol%, preferably 98 mol% alkyl groups, resulting from the polymerization of ethylene.

Alkaline earth metal alkylhydroxybenzoates (ie, carboxylates) of the present invention wherein R represents a mixture of alkyl groups are named Normal Alpha Olefin C ₂₆ -C ₂₈ or Normal Alpha Olefin C ₂₀ -C ₂₄ the chevron Phillips Chemical Company _under, by British Petroleum Co. under the name C ₂₀ -C 26 olefin, by Sheruchimie under the name SHOP C20-C22, linear alpha olefins cut such as that marketed Or a mixture of these cuts or olefins from these companies having about 20 to 28 carbon atoms.

  The —COOM group of formula (I) can be in the ortho, meta or para position relative to the hydroxyl group.

  The alkaline earth metal alkylhydroxybenzoates of the present invention can be any mixture of alkaline earth metal alkylhydroxybenzoic acids having —COOM groups in the ortho, meta, or para positions.

  The alkaline earth metal alkylhydroxybenzoates of the present invention are usually soluble in oil as characterized by the following test.

  A mixture of 600 neutral diluent oil and alkyl hydroxybenzoate with a content of 10% by weight relative to the total amount of the mixture is centrifuged at a temperature of 60 ° C. for 30 minutes. Centrifugation is performed under conditions specified by standard ASTM D2273 (it should be noted that centrifugation is performed without dilution, ie without addition of solvent). Immediately after centrifugation, the volume of deposit formed is determined. If the deposit is less than 0.05% v / v (the volume of deposit relative to the volume of mixing), the product is considered soluble in oil.

  Advantageously, the TBN of the highly overbased alkaline earth metal alkylhydroxybenzoates of the present invention is greater than 250, preferably from about 250 to 450, and more preferably from about 300 to 400, and less than 3% by volume, Preferably it has less than 2% by volume and more preferably less than 1% by volume crude oil precipitate. For the medium overbased alkaline earth metal alkylhydroxybenzoates of the present invention, the TBN is about 100 to 250, preferably about 140 to 230, less than 1% by volume, preferably less than 0.5% by volume. Usually has a crude oil deposit.

Method In a first aspect of the present invention, a method for preparing an overbased alkaline earth metal alkylhydroxylbenzoate comprises alkaline earth metal alkylhydroxybenzoate, or alkaline earth metal alkylhydroxylbenzoate and no more than 50 mole percent. Mixtures with alkylphenols (based on the total mixture of alkylhydroxylbenzoate and alkylphenol), at least one carboxylic acid having 1 to 4 carbon atoms, and aromatic hydrocarbons, aliphatic hydrocarbons, monoalcohols And overbasing with a molar excess of an alkaline earth metal base and at least one acidic overbased material in the presence of a solvent selected from the group consisting of:

Overbasing the alkaline earth metal alkylhydroxybenzoate or a mixture of alkaline earth metal alkylhydroxybenzoate and alkylphenol can be performed by any method known by those having ordinary knowledge in the art. Basic alkaline earth metal alkylhydroxybenzoates can be produced. However, it has been surprisingly found that the addition of a small amount of C ₁ -C ₄ carboxylic acid in this step reduces the crude oil precipitate obtained at the end of the overbasing step by at least 3 times.

C ₁ -C ₄ carboxylic acids used in the neutralization step comprises formic acid, acetic acid, propionic acid and butyric acid. And these can be used individually or in mixture. Preferably, a mixture of such acids is used, for example formic acid: acetic acid, about 0.1: 1 to 100: 1, preferably about 0.5: 1 to 4: 1, more preferably A formic acid: acetic acid molar ratio of about 0.5: 1 to 2: 1, most preferably about 1: 1.

  Typically, the overbasing reaction is carried out from about 10% to 70% by weight alkylhydroxybenzoic acid, from about 1% to 30% by weight alkylphenol, from about 0% to 40% by weight diluent oil, from about 20% by weight. It is carried out in the reactor in the presence of 60% by weight aromatic solvent. Stir the reaction mixture. Alkaline earth metal, monoalcohol and carbon dioxide with an aromatic solvent are added to the reaction while maintaining a temperature between about 20 ° C. and 80 ° C.

  The degree of overbasing can be controlled by the amount of alkaline earth metal, carbon dioxide and reactants added to the reaction mixture, and the reaction conditions used during the carbonation process.

The weight ratio of reagents used (methanol, xylene, slaked lime and CO ₂ ) corresponds to the following weight ratio: xylene: slaked lime is about 1.5: 1 to 7: 1, preferably about 2: 1 to 4: 1. Methanol: slaked lime is about 0.25: 1 to 4: 1, preferably about 0.4: 1 to 1.2: 1. The carbon dioxide: slaked lime has a molar ratio of about 0.5: 1 to 1.3: 1, preferably about 0.7: 1 to 1.0: 1. The C ₁ -C ₄ carboxylic acid: alkylhydroxybenzoic acid is in a molar ratio of about 0.02: 1 to 1.5: 1, preferably about 0.1: 1 to 0.7: 1.

The lime is introduced as a slurry, ie as a premix of lime, methanol, xylene and CO ₂ at a temperature between about 20 ° C. and 65 ° C. over a period of 1 to 4 hours.

In order to obtain a highly overbased material (TBN> 250) and a crude oil precipitate in the range of 0.4 to 3% by volume, preferably in the range of 0.6 to 1.8% by volume, with no performance degradation And the amount of CO ₂ is prepared. Omitting the C ₁ -C ₄ carboxylic acid, it can not reach the crude precipitate low levels. Typically, crude precipitates without C ₁ -C ₄ carboxylic acids will range from about 4 to 8% by volume.

For medium overbased materials (about 100 to 250 TBN), the amounts of lime and CO ₂ are adjusted to obtain crude oil precipitates in the range of 0.2 to 1% by volume. Crude oil precipitates that do not use C ₁ -C ₄ carboxylic acids range from about 0.8 to 3% by volume.

  In a second aspect of the invention, an overbased alkaline earth metal alkylhydroxybenzoate can be prepared by the following steps:

A. Formation of alkali metal base alkyl phenates:
In the first step, the alkylphenol is neutralized using an alkali metal base, preferably in the presence of a light solvent such as toluene, xylene isomers, light alkyl benzene to form the alkali metal base alkyl phenate. In one embodiment, the solvent forms an azeotrope with water. In another aspect, the solvent may be a monoalcohol such as 2-ethylhexanol. In this case, 2-ethylhexanol is removed by distillation prior to carboxylation. The purpose of the solvent is to facilitate water removal.

  The hydrocarbyl phenol can contain up to 100 wt% linear hydrocarbyl groups, up to 100 wt% branched hydrocarbyl groups, or linear and branched hydrocarbyl groups. If present, the straight chain hydrocarbyl group is preferably alkyl. The straight chain alkyl group then contains about 12 to 40 carbon atoms, more preferably about 18 to 30 carbon atoms. If present, the branched hydrocarbyl group is preferably alkyl and has at least 9 carbon atoms, preferably from about 9 to 40 carbon atoms, more preferably from about 9 to 24 carbon atoms, and most preferably from about 10 to 18 carbon atoms. Containing carbon atoms. In one embodiment, the hydrocarbyl phenol contains no more than 85 wt% linear hydrocarbyl phenol (preferably at least 35 wt% linear hydrocarbyl phenol) in a mixture having at least 15 wt% branched hydrocarbyl phenol. In one embodiment, the hydrocarbyl phenol is 100% linear alkylphenol.

  Since long linear alkyl chains promote the compatibility and solubility of lubricating oil additives, the use of alkylphenols containing at least 35 wt% or less long linear alkylphenols (about 18 to 30 carbon atoms) Especially attractive.

  Branched alkylphenols can be obtained by reaction of phenol and a branched olefin, usually a branched olefin derived from propylene.

  They consist of a mixture of mono-substituted isomers, most of the substituents being in the para position, very few ortho positions and little in the meta position.

  On the one hand, linear alkylphenols can be obtained by reaction of phenol with linear olefins, usually linear olefins derived from ethylene. They consist of a mixture of mono-substituted isomers, with the proportions of linear alkyl substituents in the ortho, meta and para positions being very uniformly distributed. Of course, straight chain alkylphenols can include alkyl substituents with some branching that increase the amount of para substituents, and consequently increase relative reactivity to alkali metal bases. Can do.

  Alkali metal bases that can be used to perform this step include lithium, sodium or potassium oxides or hydroxides. As a preferred embodiment, potassium hydroxide is preferred. Another preferred example is sodium hydroxide.

  The purpose of this step is to obtain an alkyl phenate with less than 2000 ppm, preferably less than 1000 ppm, and more preferably less than 500 ppm water.

  In this regard, the first step is performed at a temperature high enough to remove water. In one embodiment, the product is placed under a slight vacuum to require a low reaction temperature.

In one embodiment, in the first step, xylene is used as the solvent and the reaction is carried out at a temperature between 130 ° C. and 155 ° C. and an absolute pressure of 800 mbar (8 × 10 ⁴ Pa).

  In other embodiments, 2-ethylhexanol is used as the solvent. Since the boiling point of 2-ethylhexanol (184 ° C.) is significantly higher than xylene (140 ° C.), the reaction is carried out at a temperature of at least 150 ° C.

To complete the water reaction distillation, the pressure is gradually reduced below atmospheric pressure. Preferably, the pressure is reduced to 70 mbar (7 × 10 ³ Pa) or less.

By performing the operation at a sufficiently high temperature and providing that the reactor pressure is gradually reduced below atmospheric pressure, the formation of the alkali metal base alkyl phenate is carried out without the need to add a solvent, Forms an azeotrope with the water formed during the reaction. For example, the temperature is heated to 200 ° C. and the pressure is gradually reduced below atmospheric pressure. Preferably, the pressure is reduced to 70 mbar (7 × 10 ³ Pa) or less.

  Water removal is carried out over a period of at least 1 hour, preferably at least 3 hours.

  The amount of reagent used should correspond to the following molar ratio: alkali metal base: alkylphenol is about 0.5: 1 to 1.2: 1, preferably about 0.9: 1 to 1.05. 1: Solvent: Alkylphenol (wt: wt) is about 0.1: 1 to 5: 1, preferably about 0.3: 1 to 3: 1.

B. Carboxylation:
This carboxylation step is carried out by simply bubbling carbon dioxide (CO ₂ ) into the reaction medium resulting from the previous neutralization step, and at least 50 mol% of the starting alkylphenol is alkyl hydroxybenzoic acid (by potentiometric determination). Until measured) (measured as hydroxybenzoic acid).

At least 50 mol%, preferably 75 mol%, and more preferably 85 mol% of the starting alkylphenol is at a temperature between about 110 ° C. and 200 ° C., from about atmospheric to 15 bar (15 × 10 ⁵ Pa), preferably Convert to alkyl hydroxyl benzoate using carbon dioxide under a pressure in the range of 1 bar (1 × 10 ⁵ Pa) to 5 bar (5 × 10 ⁵ Pa) for a period of between about 1 and 8 hours.

In one variation using a potassium salt, the temperature is between about 125 ° C. and 165 ° C., more preferably between 130 ° C. and 155 ° C., and the pressure is from about atmospheric to 15 bar (15 × 10 ⁵ Pa), preferably from about atmospheric pressure to 4 bar (4 × 10 ⁵ Pa).

In one variation using a sodium salt, the temperature is aptly lower, preferably between about 110 ° C. and 155 ° C. More preferably, it is between about 120 ° C. and 140 ° C. and about 1 bar to 20 bar (1 × 10 ⁵ to 20 × 10 ⁵ Pa), preferably 3 bar to 15 bar (3 × 10 ⁵ to 15 × 10 ⁵ Pa). Pressure.

  Carboxylation is usually performed by diluting in a solvent such as hydrocarbon or alkylate such as benzene, toluene, xylene. In this case, the solvent: hydroxybenzoate weight ratio is about 0.1: 1 to 5: 1, preferably about 0.3: 1 to 3: 1.

  In other variations, no solvent is used. In this case, carboxylation is carried out in the presence of diluent oil to avoid too sticky materials.

  The weight ratio of diluent oil: alkyl hydroxybenzoate is about 0.1: 1 to 2: 1, preferably about 0.2: 1 to 1: 1, more preferably about 0.2: 1 to 0.5: 1.

C. Acidification:
The purpose of this step is to acidify the alkyl hydroxybenzoate diluted in the solvent to give the alkylhydroxybenzoic acid. Any acid stronger than alkylhydroxybenzoic acid can be used. Usually hydrochloric acid or sulfuric acid is used.

The acidification step is carried out with an excess of H ⁺ equivalents of at least 5H + equivalent%, preferably 10H + equivalent%, and more preferably 20H + equivalent% acid to potassium hydroxide, and the acidification is complete.

  In one embodiment, sulfuric acid is used. It is diluted to about 5% to 50% by volume, preferably 10% to 30% by volume. The amount of sulfuric acid to hydroxybenzoate (salicylate) used is at least 0.525 moles, preferably at least 0.55 moles, and more preferably at least 0.6 moles of sulfuric acid per mole of hydroxybenzoate basis.

  The acidification reaction is carried out under stirring or by a suitable mixing system at a temperature of about room temperature to 95 ° C., preferably about 50 ° C. to 70 ° C., for a period related to the efficiency of the mixing. For example, when a stirred reactor is used, the period is about 15 to 300 minutes, preferably about 60 to 180 minutes. If a static mixer is used, the period may be shorter.

  At the end of this period, the agitation is stopped to ensure good phase separation before the aqueous phase separates. And after the phase separation is complete, the organic phase is neutralized, overbased, centrifuged, removed impurities and distilled to remove the solvent. The aqueous phase is treated as waste. In one embodiment, the organic phase is sent in a coalescer to reduce the level of residual moisture and resulting water soluble impurities such as sulfuric acid and potassium sulfate.

D. Contact with carboxylic acid:
The alkyl hydroxybenzoic acid of Step C is contacted with at least one carboxylic acid having about 1 to 4 carbon atoms.

E. Neutralization:
The mixture of alkyl hydroxybenzoic acid and at least one carboxylic acid from step D is at least one selected from the group consisting of alkaline earth metal bases, aromatic hydrocarbons, aliphatic hydrocarbon monoalcohols, and mixtures thereof. To form an alkaline earth metal alkylhydroxybenzoate and at least one alkaline earth metal carboxylate.

F. Overbasing:
Overbasing a mixture of the alkaline earth metal alkylhydroxybenzoic acid and alkylphenol can be performed by any method known by those having ordinary knowledge in the art to produce alkylhydroxybenzoates. However, it has been surprisingly found that the addition of a small amount of C ₁ -C ₄ carboxylic acid in this step reduces the crude oil precipitate obtained at the end of the overbasing step by at least 3 times.

C ₁ -C ₄ carboxylic acids used in the neutralization step comprises formic acid, acetic acid, propionic acid and butyric acid. And they can be used alone or in combination. Such acid mixtures, such as formic acid: acetic acid, from about 0.1: 1 to 100: 1, preferably from about 0.5: 1 to 4: 1, more preferably from about 0.5: 1. Preference is given to using a 2: 1 formic acid: acetic acid molar ratio.

  Typically, the overbasing reaction is carried out from about 10% to 70% by weight alkylhydroxybenzoic acid, from about 1% to 30% by weight alkylphenol, from about 0% to 40% by weight diluent oil, from about 20% by weight. It is carried out in the reactor in the presence of 60% by weight aromatic solvent. Stir the reaction mixture. Alkaline earth metal, monoalcohol and carbon dioxide with an aromatic solvent are added to the reaction while maintaining a temperature between about 20 ° C. and 80 ° C.

  The degree of overbasing can be controlled by the amount of alkaline earth metal, carbon dioxide and reactants added to the reaction mixture, and the reaction conditions used during the carbonation process.

The weight ratio of reagents used (methanol, xylene, slaked lime and CO ₂ ) corresponds to the following weight ratio: xylene: slaked lime is about 1.5: 1 to 7: 1, preferably about 2: 1 to 4: 1. Methanol: slaked lime is about 0.25: 1 to 4: 1, preferably about 0.4: 1 to 1.2: 1. The carbon dioxide: slaked lime has a molar ratio of about 0.5: 1 to 1.3: 1, preferably about 0.7: 1 to 1.0: 1. The C ₁ -C ₄ carboxylic acid: alkylhydroxybenzoic acid is in a molar ratio of about 0.02: 1 to 1.5: 1, preferably about 0.1: 1 to 0.7: 1.

The lime is introduced as a slurry, ie as a premix of lime, methanol, xylene and CO ₂ at a temperature between about 20 ° C. and 65 ° C. over a period of 1 to 4 hours.

In order to obtain a highly overbased material (TBN> 250) and a crude oil precipitate in the range of 0.4 to 3% by volume, preferably in the range of 0.6 to 1.8% by volume, without degradation of performance, lime and The amount of CO ₂ is prepared. Omitting the C ₁ -C ₄ carboxylic acid, it can not reach the crude precipitate low levels. Typically, crude precipitates without C ₁ -C ₄ carboxylic acids will range from about 4 to 8% by volume.

For medium overbased materials (about 100 to 250 TBN), the amount of lime and CO ₂ is adjusted to obtain a crude oil precipitate in the range of 0.2 to 1% by volume. Crude oil precipitates that do not use C ₁ -C ₄ carboxylic acids range from about 0.8 to 3% by volume.

  In a third aspect of the present invention, the overbased alkaline earth metal alkylhydroxybenzoate can be obtained by a process comprising steps A to C above, which continues to:

D. Neutralization:
The mixture of alkyl hydroxybenzoic acid from step C is in excess of a molar amount of at least one solvent selected from the group consisting of alkaline earth metal bases and aromatic hydrocarbons, aliphatic hydrocarbons, monoalcohols and mixtures thereof. To form an alkaline earth metal alkylhydroxybenzoate.

E. Contact with carboxylic acid:
Contacting the alkaline earth metal alkylhydroxybenzoate and the alkaline earth metal base formed in Step D with at least one carboxylic acid having from about 1 to 4 carbon atoms to form an alkaline earth metal alkylhydroxybenzoate; And forming a mixture of at least one alkaline earth metal carboxylate.

F. Overbasing:
The alkaline earth metal alkylhydroxybenzoate is overbased according to the above description.

  Optionally, predistillation, centrifugation, and distillation can also be utilized to remove solvents and crude oil precipitates. Some of the water, methanol, and xylene can be removed by heating between about 110 ° C and 134 ° C. This is followed by centrifugation to remove unreacted lime. Finally, in order to reach a flash point of at least about 160 ° C. as determined by the Pensky-Martens Closed Cup (PMCC) tester as described in ASTM D93, xylene is heated under vacuum Can be removed.

  In one embodiment, the lubricating oil additive composition is prepared by the methods described in US Pat. No. 5,821,905, US Pat. No. 5,334,321, US Pat. And at least one polyalkenyl succinimide prepared by other methods well known in the art, and are incorporated herein by reference).

  The lubricating oil additive composition can also contain other additives as described below. These additive components can be mixed in any order and can be mixed as a combination of components.

Other Additive Components The following additive components are examples of some components that can be used in the present invention. These examples of additives are provided to illustrate the invention, but they are not intended to limit it:

A. Metal detergents Sulfurized or non-sulfurized alkyl or alkenyl phenates, sulfonates derived from synthetic or natural feedstock, carboxylates, salicylates, phenates, sulfurized or non-sulfurized metal salts of multihydroxyalkyl or alkenyl aromatic compounds, alkyl or alkenylhydroxy Aromatic sulfonates, sulfurized or non-sulfurized alkyl or alkenyl naphthenates, metal salts of alkanoic acids, metal salts of alkyl or alkenyl multiacids, chemical and physical mixtures thereof.

B. Antioxidants Antioxidants reduce the tendency of mineral oil to worsen during operation. The deterioration here is indicated by products of oxidation such as mud and varnish deposited on the metal surface. Antioxidants include, but are not limited to, 4,4′-methylene-bis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol) 4,4′-bis (2-methyl-6-tert-butylphenol), 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 4,4′-butylden-bis (3- Methyl-6-tert-butylphenol), 4,4′-isopropylidene-bis (2,6′-di-tert-butylphenol), 2,2′-methylene-bis (4-methyl-6-nonylphenol), 2 , 2′-isobutylidene-bis (4,6-xylenol), 2,2′-methylene-bis (4-methyl-6-cyclohexylphenol), 2,6-di-tert-butyl-1--4-methyl Ruphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butyl-phenol, 2,6-di-tert-dimethylamino-p-cresol, 2,6 -Di-tert-4- (N, N'-dimethylaminomethylphenol), 4,4'-thiobis (2-methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-6-) Phenol types (phenols) such as tert-butylphenol), bis (3-methyl-4-hydroxy-5-tert-butylbenzyl) -sulfide and bis (3,5-di-tert-butyl-4-hydroxybenzyl) Of) antioxidants. Diphenylamine type antioxidants include, but are not limited to, alkylated diphenylamine, phenyl-α-naphthylamine and alkylated α-naphthylamine. Other types of antioxidants include metal dithiocarbamates (eg, zinc dithiocarbamate) and methylenebis (dibutyldithiocarbamate). Antioxidants are usually incorporated into the oil in an amount of about 0 to about 10% by weight, preferably 0.05 to about 3.0% by weight, based on the total amount of engine oil.

C. Antiwear / Super Pressure Additives As their name implies, these additives reduce the wear of moving metal parts. Examples of this type of additive include, but are not limited to, phosphates, phosphites, carbamates, esters, sulfur-containing compounds, molybdenum complexes, zinc dialkyldithiophosphates (primary alkyl, secondary alkyl and aryl types), Examples include sulfurized oil, sulfurized isobutylene, sulfurized polybutene, diphenyl sulfide, methyltrichlorostearate, chlorinated naphthalene, fluoroalkylpolysiloxane, and lead naphthenate.

D. Rust inhibitor (rust inhibitor)
1) Nonionic polyoxyethylene surfactant: polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl Ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate.
2) Other compounds: stearic acid and other fatty acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, partial carboxylic esters and phosphate esters of polyhydric alcohols.

E. Demulsifiers Addition products of alkylphenols and ethylene oxide, polyoxyethylene alkyl ethers, and polyoxyethylene sorbitan esters.

F. Friction modifiers: fatty alcohols, 1,2-diols, boronated 1,2-diols, fatty acid amines, fatty acid amides, boronated esters, and other esters.

G. Multifunctional additive Sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum organophosphorodithioate, oxymolybdenum monoglyceride, oxymolybdenum diethylate amide, amine-molybdenum complex compound and sulfur-containing molybdenum complex compound.

H. Viscosity index improver or thickener Polymethacrylate polymer, ethylene-propylene copolymer, styrene-isoprene copolymer, hydrogenated styrene-isoprene copolymer, polyisobutylene, and dispersion viscosity index improver.

I. Pour point depressant polymethyl methacrylate.

J. et al. Antifoaming agent Alkyl methacrylate polymer and dimethyl silicone polymer.

K. Metal deactivators disalicylidenepropylenediamine, triazole derivatives, mercaptobenzothiazole, thiadiazole derivatives, and mercaptobenzimidazoles.

L. Dispersants Alkenyl succinimides, alkenyl succinimides modified with other organic compounds, alkenyl succinimides modified by post-treatment using ethylene carbonate or boric acid, esters of polyhydric alcohols and polyisobutenyl succinic anhydrides, phenate-salicylate, And post-processed analogs, alkali metals or mixed alkali metals, alkaline earth metal borates, hydrated alkali metal borate dispersants, alkaline earth metal borates dispersants, polyamide ashless dispersants, etc. A mixture of dispersants. Preferably, the alkenyl succinimide is a polyalkenyl succinimide. More preferred is a polyisobutenyl succinimide in which the polyisobutenyl group has a molecular weight of about 1000 to about 2300. Alkenyl succinimides are prepared according to methods well known in the art.

Lubricating Oil Composition In one aspect, the invention relates to a lubricating oil composition comprising the lubricating oil additive composition described hereinabove and an oil of lubricating viscosity.

Oil of lubricating viscosity The lubricating oil additive composition described above is usually added to a base oil that is sufficient to lubricate moving parts such as internal combustion engines, gears, and transmissions. Typically, the lubricating oil composition of the present invention comprises a major amount of oil of lubricating viscosity and a minor amount of lubricating oil additive composition.

  The base oil used may be any of a wide variety of oils with a lubricating viscosity. The base oil of lubricating viscosity used in this type of composition may be a mineral oil or a synthetic oil. Base oils having a viscosity of at least 2.5 cSt at 40 ° C. and a pour point of less than 20 ° C., preferably 0 ° C. or less are desirable. Base oils can be derived from synthetic or natural resources.

Mineral oils for use as the base oil of the present invention include, for example, paraffins, naphthenes, and other oils commonly used in lubricating oil compositions. Synthetic oils include, for example, both hydrocarbon synthetic oils and synthetic esters and mixtures thereof having the desired viscosity. Hydrocarbon synthetic oils are prepared from hydrocarbon synthesis procedures using, for example, oils prepared from the polymerization of ethylene, polyalphaolefins, ie PAO oils, or carbon monoxide and hydrogen gas as in the Fischer-Tropsch process. Oil can be included. Useful synthetic hydrocarbon oils include liquid polymers of alpha olefins having a suitable viscosity. In particular, hydrogenated liquid oligomers of C ₆ to C ₁₂ alpha olefins such as 1-decent trimer are useful. Similarly, alkylbenzenes of suitable viscosity such as didodecylbenzene can be used. Useful synthetic esters include monocarboxylic and polycarboxylic acids and esters of monohydroxyalkanols and polyols. Typical examples are didodecyl adipate, pentaerythritol tetracaproate, di-2-ethylhexyl adipate, dilauryl sebacate and the like. Complex esters prepared from mixtures of mono and dicarboxylic acids and mono and dihydroxy alkanols can also be used. Blends of mineral oil and synthetic fats are also beneficial.

  Thus, the base oil can be a refined paraffin type base oil of lubricating viscosity, a refined naphthenic base oil, or a synthetic or non-hydrocarbon oil. The base oil can also be a mixture of mineral and synthetic oils.

Additive Package In another aspect, the invention relates to an additive concentrate for an engine oil containing a first carboxylate detergent, a second carboxylate detergent, and a polyalkenyl succinimide. In another aspect, the invention provides an engine oil comprising a first carboxylate detergent having a TBN of about 60 to about 200 TBN, a second carboxylate having a TBN of about 200 to about 400 TBN, and a polyalkenyl succinimide. Relates to additive concentrates for The lubricant additive composition concentrates described hereinabove are substantially inert, usually liquid organic diluents (eg, mineral oil, naphtha, benzene, toluene or the like that form additive concentrates). Xylene) can be provided as an additive package or concentrate. These concentrates typically comprise about 1% to about 99% by weight of this type of diluent, and in one embodiment about 10% to about 90% by weight. Typically, synthetic oils and other organic liquids compatible with additives and finished lubricants can also be used, but a viscosity of about 4 to about 8.5 cSt at 100 ° C., preferably about 100 ° C. A neutral oil with a viscosity of 4 to about 6 cSt is used as the diluent.

  One aspect of the present invention is a method of operating a diesel locomotive engine comprising the step of lubricating the diesel locomotive engine with a lubricating oil composition, wherein the lubricating oil composition comprises a major component of oil of lubricating viscosity. And said lubricating additive package, wherein the lubricating additive package comprises a first carboxylate detergent, a second carboxylate detergent, and a polyalkenyl succinimide.

  One aspect of the present invention is a method of operating an inland marine engine comprising the step of lubricating the inland marine engine with a lubricating oil composition, wherein the lubricating oil composition comprises an oil of lubricating viscosity. And a lubricant additive package, wherein the lubricant additive package comprises a first carboxylate detergent, a second carboxylate detergent, and a polyalkenyl succinimide.

  One aspect of the present invention is a method for improving TBN retention, wherein the lubricating oil composition comprises a major amount of oil of lubricating viscosity and the lubricating additive package described above, wherein the lubricating additive package comprises: It relates to the above process comprising a first carboxylate detergent, a second carboxylate detergent, and a polyalkenyl succinimide.

Example

Base Lubricating Oil Composition A lubricating oil composition comprising a polyisobutenyl succinimide having a molecular weight of 2300 polyisobutenyl groups, a 263 TBN oil concentrate of a phenate detergent, a 114 TBN oil concentrate of a phenate detergent, and a Mannich base alkylphenol Prepared by mixing calcium salt, at least one antioxidant, antifoam, and Group I base oil.

  Comparative Example 1-8 was mainly composed of a base lubricating oil composition (see Table 1). Examples 1-7 (examples of the present invention) include a base lubricating oil composition and at least two carboxylate detergents—a 350 TBN oil concentrate of a carboxylate detergent and a 150 TBN concentrate of a carboxylate detergent (Table 2). reference).

  Each of the comparative oils was tested in B2-7, otherwise known as the Union Pacific Oxidation Test. The test method is described below.

B2-7 Test / Union Pacific Oxidation Test The B2-7 test is an oxidation test with the following conditions:

  According to the B2-7 test, the oil to be tested is heated at 300 ° F. for 96 hours with bubbling oxygen. A piece of copper, iron and lead is suspended in the oil. 50 milliliter samples are removed at 48, 72 and 96 hours. The sample is replenished with fresh oil at 48 and 72 hours. The oil test sample is evaluated for base number, acid number, pH and lead.

  Samples of the comparative example (Comparative Example 1-8) and the example of the present invention (Example 1-7) were reduced in total base number (Total Base Number (TBN)) and per million of lead found in oil. Was evaluated for lead corrosion measured as parts of (ie, ppm of pb).

  For TBN reduction, a higher number indicates a greater reduction of base in the oil and is less preferred. Similarly, higher numbers for pb (ppm) indicate greater lead corrosion and are less preferred. Oils for extended use in locomotive diesel engines ideally retain TBN and show no corrosion to lead.

B2-7 Results Based on the results of the tests, the lubricating oil composition of Examples 1-7 of the present invention exhibited a low value of TBN reduction and therefore the base of the lubricating oil was not reduced as much as the comparative example. It is obvious. In particular, when Example 1-7 was compared with Comparative Example 1-8, the TBN reduction improved by 30% or more.

  In addition, lead corrosion was reduced in the oil samples that were Examples 1-7. The amount of lead corrosion is particularly low when compared with the lead corrosion result of the oil of Comparative Example 1-8. Specifically, the lead corrosion measurement of Example 1-7 (invention) shows a lead measurement of 10-15% of the measurement of the comparative example.

  The lubricating oil composition contains at least two carboxylate detergents and represents a very significant improvement with respect to TBN retention and lead corrosion over the carboxylate-free oil used in the present invention.

Claims (7)

a. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
b. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and c. A lubricating oil additive composition comprising at least one polyalkenyl succinimide.   The lubricating oil additive composition of claim 1, wherein the polyalkenyl succinimide is polyisobutenyl succinimide. a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. A lubricating oil composition comprising at least one polyalkenyl succinimide.   The lubricating oil composition according to claim 3, wherein the lubricating oil composition is used as a railway engine oil. A method of operating a diesel locomotive engine comprising the step of lubricating a diesel locomotive engine with a lubricating oil composition, wherein the lubricating oil composition comprises:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. Including at least one polyalkenyl succinimide,
Said method. A method of operating an inland vessel engine, comprising the step of lubricating an inland vessel engine with a lubricating oil composition, wherein the lubricating oil composition comprises:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to about 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. Including at least one polyalkenyl succinimide,
Said method. A method of improving TBN retention comprising lubricating an engine with a lubricating oil composition, the lubricating oil composition comprising:
a. A major amount of oil of lubricating viscosity;
b. A first carboxylate detergent having an active TBN of greater than about 200 to 400;
c. A second carboxylate detergent having greater than about 60 to about 200 active TBN; and d. Having at least one polyalkenyl succinimide,
Said method.