JP4921697B2 - Low emission diesel lubricant with improved corrosion protection - Google Patents

Description

  The present invention relates to an engine lubricant for a low emission (low emission) diesel engine equipped with an exhaust gas aftertreatment device that is sensitive to a lubricant component. Some aftertreatment devices of this type are known to be sensitive to fuel and lubricant components. In order to ensure the durability of these aftertreatment devices, lubricants characterized by low levels of ash, sulfur and phosphorus have been developed. Ash, sulfur and phosphorus are present in many conventional lubricating additives such as detergents and zinc dithiophosphate. In order to meet the maximum ash, sulfur and phosphorus level requirements, a novel component and combination of components was used to develop the low emission diesel lubricant ("LEDL") of the present invention.

  Known LEDLs meet the requirements for maximum ash, sulfur and phosphorus levels, but fail to meet the minimum anticorrosion requirements. The novel LEDL additive formulation described in the present invention solves the corrosion problem while maintaining good performance in other areas. The blends can be used in finished oils blended with one, two, three or four base oil feedstocks, or combinations thereof. Finished oils using this formulation may or may not contain viscosity modifiers, pour point depressants, and any esters added for solubility.

  In the past, efforts have been made to reduce the amount of sulfur in lubricating oil compositions.

  For example, Patent Document 1 includes (a) 0.5-3 mass% primary zinc dithiophosphate, (b) 1.2-4 mass% alkaline earth metal detergent and dispersant, (c) 1 5-10% by weight of bis-type alkenyl succinimide or a derivative thereof, (d) 0.3-3% by weight of an amine salt of a phosphate ester, (e) 0.05-5% by weight of one or more types of sulfur Gear oils containing a compound and (f) a base oil having 0.1 wt% or less sulfur are taught.

  In order to further reduce the sulfur content in the lubricating oil composition, a sulfur-free detergent can be used. The production of hydrocarbon phenates and hydrocarbon salicylates, both with and without sulfur, are well known in the art.

  Patent Document 2 discloses the production of a detergent dispersion additive based on a highly basic alkaline earth metal sulfurized alkylphenate. These additives are produced by sulfurization of alkylphenols, neutralization of sulfurized alkylphenols with alkaline earth metal bases, followed by peralkalization by carbonation of alkaline earth metal bases dispersed in sulfurized alkylphenates.

  Patent Document 3 discloses a cleaning additive based on a calcium sulfide alkyl salicylate. These additives include carboxylation of potassium alkyl phenates, exchange with calcium chloride, followed by sulfurization of calcium alkyl salicylates obtained with sulfur in the presence of lime, carboxylic acids and alkylene glycols or alkyl ethers of alkylene glycols. Manufactured by.

  Patent Document 4 discloses a peralkalized cleaning and dispersing additive based on alkyl phenate and alkyl salicylate. These additives include neutralization of alkylphenols with alkaline earth metal bases in the presence of acids and solvents, solvent distillation, carboxylation, sulfidation and hydrogenation with sulfur and alkaline earth metal bases in the presence of glycols and solvents. Prepared by alkalinization followed by carbonation and filtration.

  US Pat. No. 6,057,086 substantially describes the performance of alkylphenate / alkyl salicylate additives, particularly in tests related to foaming in fresh oil, mixing and dispersibility, and stability tests against hydrolysis. A method that can be improved is disclosed. This method consists of neutralizing linear and branched alkylphenol mixtures with alkaline earth metal bases in the presence of carboxylic acids, carboxylation of alkylphenates by the action of carbon dioxide, followed by sulfidation and peralkalization, It then consists of carbonation, distillation, filtration and degassing in the atmosphere.

  Patent Document 6 discloses a detergent-dispersing additive containing no mixture of an alkaline earth metal salt (alkyl phenate / alkyl salicylate) and unreacted alkylphenol and containing no unsulfurized alkali metal. This additive improves antioxidant properties, high temperature deposit control and black sludge control.

  Patent Documents 7 and 8 have 40% to 60% alkylphenol, 10% to 40% alkaline earth alkyl phenate, and 20% to 40% alkaline earth monoaromatic alkyl salicylate. A cleaning dispersant composition free of unsulfurized alkali metals is taught. The composition may comprise an alkaline earth diaromatic alkyl salicylate as long as the molar ratio of monocyclic alkyl salicylate to diaromatic alkyl salicylate is at least 8: 1. This composition can be made by a three-stage process involving neutralization of the alkylphenol, carboxylation of the resulting alkyl phenate, and filtration of the product of the carboxylation step. The detergent dispersant produced by this method can be used in engine lubricating oil compositions to improve antioxidant properties, high temperature deposit control and black sludge control.

Japanese Patent Laid-Open No. 11-181463 US Pat. No. 3,036,971 French Patent No. 1563557 Specification French patent application No. 2625220 US Pat. No. 5,808,145 European Patent Application No. 0933417 US Pat. No. 6,162,770 US Pat. No. 6,626,2001

  It would be desirable to find low sulfur, ash and phosphorus lubricants with excellent corrosion resistance. The LEDL of the present invention is a low sulfur, ash and phosphorus lubricant with excellent corrosion performance.

  The present invention provides a novel low emission diesel lubricant, or LEDL, containing low levels of ash, sulfur and phosphorus. Preferably, the LEDL also comprises an unsulfurized carboxylate-containing hydroxy-aromatic consisting of a mixture of alkaline earth metal salts (alkyl phenate / alkyl salicylate) and reduced amounts of unreacted hydrocarbon phenol. It also contains detergent-dispersing additives based on surfactants. The invention also relates to additive packages, concentrates and finished oil compositions containing the same. Most preferably, the invention relates to the LEDL, wherein the hydrocarbon salicylate is primarily a single aromatic ring hydrocarbon salicylate.

  In a preferred embodiment, the present invention is a detergent dispersion additive based on an unsulfurized carboxylate-containing hydroxy-aromatic surfactant for lubricating oils, comprising an alkaline earth metal salt mixture (alkyl phenate / alkyl The present invention relates to a novel LEDL comprising an additive consisting of salicylate) and an unreacted hydrocarbon phenol with a reduced amount, and an additive package, concentrate and finished oil composition comprising the same. In particular, in a preferred embodiment, the invention relates to an LEDL comprising the unsulfurized carboxylate-containing additive comprising the mixture wherein the hydrocarbon salicylate is primarily a monoaromatic hydrocarbon salicylate. This additive improves the antioxidant properties of lubricants, high temperature deposit control, BN retention, corrosion control and black sludge control. The invention also relates, in part, to novel methods for making and using the LEDL.

  The LEDL of the present invention can have, for example, the following composition: a major amount of base oil of lubricating viscosity; containing 40 weight percent (“wt%”) or less of free hydrocarbon phenol (free hydrocarbyl phenol), Hydroxy-aromatic surfactant-based detergent dispersion additives (hydroxy-aromatic surfactant-based detergent dispersion additives); dispersants; antiwear agents; and from about 0% to about 1.2% by weight Ash (as measured by ASTM D874); from about 0.1% to about 0.5% sulfur; and from about 0.02% to about 0.1% phosphorus. Preferably, the LEDL of the present invention comprises a major amount of a base oil of lubricating viscosity and an ash content of about 0.4% to about 1.0% by weight; about 0.05% to about 0.3% by weight of sulfur. And from about 0.02% to about 0.08% by weight phosphorus. More preferably, the LEDL contains a major amount of a base oil of lubricating viscosity and 1.0 wt% or less ash; 0.3 wt% or less sulfur; and 0.08 wt% or less phosphorus. Most preferably, the LEDL comprises a major amount of a base oil of lubricating viscosity, and about 0.4 wt% to about 1.0 wt% ash; about 0.05 wt% to about 0.15 wt% sulfur; And about 0.02% to about 0.08% by weight phosphorus.

  In some embodiments, the LEDL also contains a corrosion inhibitor. In a preferred embodiment, the hydroxy-aromatic surfactant-based cleaning dispersion additive is unsulfurized. The additive is preferably a carboxylate-containing additive. More preferably, the additive comprises 10-50% alkaline earth metal hydrocarbon phenate, 15-60% alkaline earth metal monoaromatic hydrocarbon salicylate, and 0-50% organic diluent. .

  In a preferred embodiment, the LEDL has a major amount of base oil of lubricating viscosity and about 0% to about 1.2% ash, about 0.1% to about 0.5% sulfur, about 0.0%. Detergent dispersion additive based on 02% to about 0.1% by weight phosphorus and from about 1.8% to about 5.5% by weight unsulfurized carboxylate-containing hydroxy-aromatic surfactant And the additive comprises (a) up to 40% hydrocarbon phenol, (b) 10-50% alkaline earth metal hydrocarbon phenate, (c) 15-60% alkaline earth metal simplex. It consists of an aromatic hydrocarbon salicylate and (d) 0-50% organic diluent.

  In another aspect, the LEDL further comprises from about 1.0 wt% to about 4.0 wt% borated dispersant, from about 0.2 wt% to about 1.1 wt% antiwear agent, and about 0 wt%. Contains from wt% to about 0.5 wt% corrosion inhibitor. More preferably, the dispersant is succinimide, the antiwear agent is zinc dithiophosphate, and the corrosion inhibitor is neutralized terephthalic acid. Most preferably, the LEDL is also from about 3.0 wt% to about 8.0 wt% non-borated dispersant, from about 0.6 wt% to about 1.4 wt% calcium sulfonate, about 0.1 wt% From about 0.5% to about 0.5% by weight molybdenum antioxidant, from about 0% to about 1.0% phenolic antioxidant, from about 0.1% to about 1.0% amine-based oxidation. Also included is an inhibitor, from about 0% to about 6.0% by weight dispersant olefin copolymer, and from about 0 to about 25 ppm antifoaming agent.

  The LEDL of the present invention preferably does not contain a sulfur-containing detergent.

  In some embodiments, the hydroxy-aromatic surfactant-based cleaning dispersion additive is 0 to 35% free hydrocarbon phenol, preferably 0 to 30% free hydrocarbon phenol, more preferably 0 to 20%. % Free hydrocarbon phenol, most preferably 0-15% free hydrocarbon phenol.

  The LEDL of the present invention advantageously comprises a major amount of base oil of lubricating viscosity and from about 0.4% to about 1.0% ash, from about 0.2% to about 0.4% by weight sulfur. About 0.04 wt.% To about 0.08 wt.% Phosphorus, and about 2.7 wt.% To about 5.5 wt.% Unsulfurized carboxylate-containing additive, and the additive is ( a) 40% or less hydrocarbon phenol, (b) 10-50% alkaline earth metal hydrocarbon phenate, (c) 15-60% alkaline earth metal monoaromatic hydrocarbon salicylate, and (d) 0 % To 50% organic diluent. The LEDL can further contain from about 1.0 wt% to about 4.0 wt% borated dispersant, and from about 0 wt% to about 0.5 wt% corrosion inhibitor. Most preferably, the LEDL is from about 3.0 wt% to about 8.0 wt% non-borated dispersant, from about 0.6 wt% to about 1.4 wt% calcium sulfonate, about 0.2 wt% % To about 1.1% by weight zinc dithiophosphate, about 0.1% to about 0.5% by weight molybdenum antioxidant, about 0% to about 1.0% by weight phenolic antioxidant, Also from about 0.1 wt% to about 1.0 wt% amine antioxidant, from about 0 wt% to about 6.0 wt% dispersant olefin copolymer, and from about 0 to about 25 ppm defoamer contains. The LEDL preferably has a sulfur content of about 0.1 wt% to about 0.3 wt%.

  The present invention also provides an effective corrosion inhibiting amount of an unsulfurized carboxylate-containing hydroxy-aromatic surfactant produced by a process comprising a major amount of a base oil of lubricating viscosity; a dispersant; an antiwear agent; Provided is an LEDL composition containing an agent-based cleaning dispersion additive: (a) Hydrocarbon phenol is neutralized in the presence of an accelerator with an alkaline earth base to produce a hydrocarbon phenate (B) subjecting the hydrocarbon phenate obtained in step (a) with carbon dioxide, under carboxylation conditions sufficient to convert at least 20 mol% of the starting hydrocarbon phenol to a hydrocarbon salicylate, Carboxylating; and (c) separating at least about 10% of the starting hydrocarbon phenol from the product formed in step (b) to form the additive. However, the composition includes: about 0 wt% to about 1.2 wt% ash; about 0.1 wt% to about 0.5 wt% sulfur; and about 0.02 wt% To about 0.1 weight percent phosphorus.

  The promoter consists of a carboxylic acid containing at least one carbon atom of 1 to 4 and the neutralization step is carried out in the absence of an alkali base, in the absence of a dialcohol and in the absence of a monoalcohol. It is preferable. The neutralization step is followed by carboxylation of the hydrocarbon phenate produced in the neutralization step and separation of the starting hydrocarbon phenol from the product of the carboxylation step.

  In the above preparation of detergent dispersion additives based on unsulfurized carboxylate-containing hydroxy-aromatic surfactants, the hydrocarbon phenol may contain linear and / or branched hydrocarbon components. For example, the hydrocarbon phenol may be composed entirely of linear hydrocarbon phenols, may be composed entirely of branched chain hydrocarbon phenols, or may be composed of a mixture of both. Good. Preferably, the hydrocarbon phenol comprises up to 85% linear hydrocarbon phenol in admixture with at least 15% branched hydrocarbon phenol in which the branched hydrocarbon group contains at least 9 carbon atoms. More preferably, the hydrocarbon phenol comprises 35% to 85% linear hydrocarbon phenol in admixture with 15% to 65% branched chain hydrocarbon phenol, wherein the ratio of branched chain to linear alkylphenol is by weight It is. The linear hydrocarbon group preferably contains 12 to 40 carbon atoms, more preferably 18 to 30 carbon atoms, and if a branched chain hydrocarbon phenol is present, a branched chain carbonization is present. The hydrogen group contains at least 9 carbon atoms, preferably 9-24 carbon atoms, more preferably 10-15 carbon atoms.

  The alkaline earth base is preferably selected from the group consisting of calcium oxide, calcium hydroxide, magnesium oxide and mixtures thereof.

  The carboxylic acid is preferably a mixture of formic acid and acetic acid, more preferably a 50/50 mixture by weight of formic acid and acetic acid.

The neutralization step is preferably performed at a temperature of at least 200 ° C, more preferably at least 215 ° C. In order to remove the water of reaction, the pressure is gradually reduced below atmospheric pressure in the absence of any solvent capable of forming an azeotrope with water. The amount of reagent used preferably corresponds to the following molar ratio:
(1) Alkaline earth base / hydrocarbon phenol is 0.2: 1 to 0.7: 1, more preferably 0.3: 1 to 0.5: 1, and (2) carboxylic acid / hydrocarbon phenol is 0.01: 1 to 0.5: 1, more preferably 0.03: 1 to 0.15: 1.

In one embodiment, the neutralization step is carried out at a temperature of at least 240 ° C. and gradually lowering the pressure below atmospheric pressure to reach a pressure of 7000 Pa (70 mbar) or less at 240 ° C. The hydrocarbon phenate obtained in the neutralization step is carboxylated using carbon dioxide under carboxylation conditions to convert at least 20 mol% of the starting hydrocarbon phenol to hydrocarbon salicylate. Preferably, at least 22 mol% of the starting hydrocarbon phenol is converted and this conversion is carried out at a temperature of 180 ° C. to 240 ° C. under a pressure in the range of up to 15 × 10 ⁵ Pa (15 bar) above atmospheric pressure. And occurs over 1 to 8 hours.

More preferably, the starting hydrocarbon phenol is an alkylphenol and at least 25 mol% of the starting alkylphenol is used at a temperature of 4 × 10 ⁵ Pa (4 bar) at a temperature equal to or higher than 200 ° C. using carbon dioxide. Convert to alkyl salicylate below.

  The hydrocarbon salicylate produced in the carboxylation step includes both single aromatic ring hydrocarbon salicylates and diaromatic hydrocarbon salicylates. The molar ratio of monoaromatic hydrocarbon salicylate to diaromatic hydrocarbon salicylate is preferably at least 8: 1.

  The product of the carboxylation step is then preferably filtered to remove any sediment produced in the carboxylation step.

  The product of the carboxylation step is then subjected to a separation step such as solvent extraction, distillation and membrane filtration to separate at least about 10% of the starting hydrocarbon phenol from the product of the carboxylation step. Preferably, at least about 30% to 55% of the starting hydrocarbon phenol is separated. More preferably, at least about 45% to 50% of the starting hydrocarbon phenol is separated from the product of the carboxylation step.

  Once the starting hydrocarbon phenol is separated from the product of the carboxylation step, the hydrocarbon phenol can be advantageously recycled and used as a starting material in the process of the present invention or any other process. .

  The separation step is preferably performed by distillation, more preferably by falling film distillation or short path distillation, and most preferably by wiping film evaporator distillation. The distillation is conducted at a temperature of about 150 ° C. to about 250 ° C. and a pressure of about 0.1 to about 4 mbar, more preferably about 190 ° C. to about 230 ° C. and about 0.5 to about 3 mbar, most preferably Is performed at about 195 to about 225 ° C. and a pressure of about 1 to about 2 mbar.

  Prior to addition to the LEDL composition of the present invention, advantageously, a detergent dispersion additive based on an unsulfurized carboxylate-containing hydroxy-aromatic surfactant is blended with an effective viscosity improving amount of an organic diluent. can do. Preferably, a sufficient amount of diluent is added so that the diluent comprises from about 10% to about 80% by weight of the blend product. More preferably, a sufficient amount of diluent is added so that the diluent comprises from about 20% to about 50% by weight of the blend product. Suitable diluents include one or two base oils such as 100N base oil; organic solvents such as pentane, heptane, benzene and toluene; and other suitable organic compounds such as advantageous in the distillation step of the present invention. And hydrocarbon phenols that can be recycled.

The detergent dispersion additive based on unsulfurized carboxylate-containing hydroxy-aromatic surfactant produced by the above method has the following composition:
(A) less than 40% hydrocarbon phenol,
(B) 10% to 50% alkaline earth metal hydrocarbon phenate;
(C) 15% to 60% alkaline earth metal monoaromatic hydrocarbon salicylate, and (d) 0% to 50% organic diluent.

  The undispersed carboxylate-containing hydroxy-aromatic surfactant-based detergent-dispersing additive may also contain alkaline earth metal diaromatic hydrocarbon salicylates, but the monoaromatic hydrocarbon salicylates The molar ratio of the aromatic hydrocarbon salicylate is at least 8: 1.

  The LEDL of the present invention is used as an engine lubricating oil composition comprising a major amount of lubricating oil, a hydroxy-aromatic surfactant-based cleaning and dispersing additive, and preferably at least one other additive. Can do. Examples of other additives that can be used include metal-containing detergents; ashless dispersants; borated and non-borated dispersants including ethylene carbonate treated dispersants; low overbasing ("LOB"), Medium overbased (“MOB”), high overbased (“HOB”) and ultra-high overbased (“HHOB”) calcium sulfonates; antioxidants, rust inhibitors, demulsifiers, extreme pressure agents, friction Mention may be made of relaxation agents, multifunctional additives, viscosity index improvers, pour point depressants and antifoaming agents.

  In automotive applications, the high-temperature deposit inhibiting performance, corrosion inhibiting and antioxidant performance of the lubricating oil can be improved by adding the LEDL composition of the present invention in an effective amount to the lubricating oil. Therefore, the corrosion resistance of the engine can be improved by bringing the LEDL of the present invention into contact with an arbitrary internal combustion engine.

  In its broadest aspect, the present invention provides LEDL compositions comprising low levels of ash, sulfur and phosphorus. Advantageously, the LEDL consists of hydrocarbon phenol, alkaline earth metal hydrocarbon phenate and alkaline earth metal monoaromatic hydrocarbon salicylate, BN retention, corrosion performance, internal oxidation, high temperature deposit control, black sludge control It may contain undispersed carboxylate-containing hydroxy-aromatic surfactant-based detergent dispersion additives useful for improving thermal oxidation stability and other properties of lubricating oils.

  Before describing the present invention in further detail, the following terms will be defined:

[Definition]
The following terms, as used herein, have the following meanings unless otherwise indicated:

  “Hydrocarbon group” means an alkyl group or an alkenyl group.

  “Metal” means an alkali metal, an alkaline earth metal, or a mixture thereof.

  “Alkaline earth metal” means calcium, barium, magnesium, strontium, or mixtures thereof.

  “Salicylate” means a metal salt of salicylic acid.

  “Alkaline earth metal monoaromatic hydrocarbon salicylate” means an alkaline earth metal salt of hydrocarbon salicylic acid in which only one hydrocarbon salicylate anion is present for each alkaline earth metal base cation.

  “Alkaline earth metal monoaromatic alkyl salicylate” means an alkaline earth metal monoaromatic hydrocarbon salicylate in which the hydrocarbon group is an alkyl group.

  “Alkaline earth metal diaromatic hydrocarbon salicylate” means an alkaline earth metal salt of hydrocarbon salicylic acid in which there are two hydrocarbon salicylate anions for each alkaline earth metal base cation.

  “Alkaline earth metal diaromatic alkyl salicylate” means an alkaline earth metal diaromatic hydrocarbon salicylate in which the hydrocarbon group is an alkyl group.

  “Hydrocarbon phenol” means a phenol having one or more hydrocarbon substituents, wherein the at least one hydrocarbon substituent contains a sufficient number of carbon atoms to impart oil solubility to the phenol.

  “Alkylphenol” means a phenol having one or more alkyl substituents, wherein at least one alkyl substituent contains a sufficient number of carbon atoms to impart oil solubility to the phenol.

  “Phenate” means a metal salt of a phenol.

  “Hydrocarbon phenate” means a metal salt of a hydrocarbon phenol (hydrocarbylphenol).

  “Alkaline earth metal hydrocarbon phenate” means an alkaline earth metal salt of a hydrocarbon phenol.

  “Alkaline earth metal alkyl phenate” means an alkaline earth metal salt of an alkylphenol.

  “Phenate-stearate” means phenate treated with stearic acid or an anhydride or salt thereof.

  “Long-chain carboxylic acid” means a carboxylic acid having an alkyl group having an average carbon number of 13 to 28. The alkyl group may be linear, branched or a mixture thereof.

  “Carboxy-stearate” means an alkaline earth metal monoaromatic hydrocarbon salicylate treated with a long chain carboxylic acid, anhydride or salt thereof.

  “Major amount” means at least about 40% by weight.

  “Unsulfurized” means that sulfur may be contained in an amount of 0.1% by weight or less.

  “Base number” or “BN” means the amount of base equivalent to milligrams of KOH per gram of sample. Therefore, the higher the BN value, the stronger the alkalinity of the product, thus reflecting the higher alkalinity held. The BN of the sample can be determined by ASTM test number D2896 or any other equivalent method.

  Unless otherwise specified, all percentages are weight percentages.

[Production of detergent dispersion additive based on unsulfurized carboxylate-containing hydroxy-aromatic surfactant]
A) Neutralization step In the first step, the hydrocarbon phenol is neutralized in the presence of an accelerator. In some embodiments, in the presence of at least one C ₁ -C ₄ carboxylic acid using an alkaline earth metal base, to neutralize the hydrocarbon phenol. This reaction is preferably carried out in the absence of an alkali base and in the absence of dialcohol or monoalcohol.

  Hydrocarbon phenols may contain up to 100% linear hydrocarbon groups, up to 100% branched hydrocarbon groups, or both linear and branched hydrocarbon groups. The linear hydrocarbon group, if present, is preferably alkyl, and the linear alkyl group preferably contains 12 to 40 carbon atoms, more preferably 18 to 30 carbon atoms. Branched hydrocarbon groups, if present, are preferably alkyl and contain at least 9 carbon atoms, preferably 9 to 24 carbon atoms, more preferably 10 to 15 carbon atoms. In some embodiments, the hydrocarbon phenol comprises up to 85% linear hydrocarbon phenol (preferably at least 35% linear hydrocarbon phenol) in admixture with at least 15% branched chain hydrocarbon phenol.

  The use of alkylphenols containing at least 35% long-chain linear alkylphenols (18-30 carbon atoms) is particularly attractive because long linear alkyl chains are miscible and soluble in additives in lubricating oils. It is because it prompts. However, the presence of relatively heavy linear alkyl groups in alkylphenols makes the latter less reactive than branched alkylphenols, and thus a much more severe reaction to effect neutralization with alkaline earth metal bases. You need to use conditions.

  Branched alkylphenols can be obtained by reacting phenol with a branched chain olefin, generally an olefin generated from propylene. They consist of a mixture of mono-substituted isomers, the majority of the substituents being in the para position, very slightly in the ortho position, and hardly in the meta position. This makes the phenol function substantially free of steric hindrance, which makes it relatively reactive to alkaline earth metal bases.

  On the other hand, linear alkylphenol can be obtained by reacting phenol with a linear olefin, generally an olefin generated from ethylene. They consist of a mixture of monosubstituted isomers and the proportions of ortho, para and meta positions of the linear alkyl substituents are more evenly distributed. This makes it difficult to react to alkaline earth metal bases because of the considerable steric hindrance, making phenolic functions less accessible due to the presence of much closer, generally heavy alkyl substituents. Of course, linear alkylphenols may contain any branched alkyl substituents that increase the amount of para substituents and consequently increase the relative reactivity to alkaline earth metal bases.

  Alkaline earth metal bases that can be used to perform this step include calcium, magnesium, barium or strontium oxides or hydroxides, especially calcium oxide, calcium hydroxide, magnesium oxide. And mixtures thereof. In some embodiments, slaked lime (calcium hydroxide) is preferred.

The accelerator used in this step may be any substance that increases 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 -C ₄ carboxylic acids including, for example, formic acid, acetic acid, propionic acid and butyric acid are used in this step and may be used alone or in a mixture. It is preferred to use a mixture of acids, most preferably a formic acid / acetic acid mixture. The molar ratio of formic acid / acetic acid should be between 0.2: 1 and 100: 1, preferably between 0.5: 1 and 4: 1 and most preferably 1: 1. The carboxylic acid acts as a transfer agent that helps the alkaline earth metal base transfer from the inorganic reagent to the organic reagent.

  The neutralization operation is performed at at least 200 ° C, preferably at least 215 ° C, and more preferably at least 240 ° C. The pressure is gradually reduced below atmospheric pressure in order to distill off the water of reaction. Therefore, neutralization should be carried out in the absence of any solvent that can form an azeotrope with water. Preferably, the pressure is reduced to 7000 Pa (70 mbar) or less.

The amount of reagent used should correspond to the following molar ratio:
(1) Alkaline earth base / hydrocarbon phenol 0.2: 1 to 0.7: 1, preferably 0.3: 1 to 0.5: 1, and (2) Carboxylic acid / hydrocarbon phenol 0 .01: 1 to 0.5: 1, preferably 0.03: 1 to 0.15: 1.

At the end of this neutralization step, the resulting hydrocarbon phenate is stirred for 15 hours at a temperature of at least 215 ° C. and at an absolute pressure of between 5000 and 10 ⁵ Pa (between 0.05 and 1.0 bar). It is preferable to maintain the period not exceeding. More preferably, the hydrocarbon phenate obtained at the end of this neutralization step is maintained at an absolute pressure between 10,000 and 20000 Pa (between 0.1 and 0.2 bar) for 2 to 6 hours.

  If the operation is carried out at a sufficiently high temperature and the reactor pressure is gradually reduced below atmospheric pressure, the neutralization reaction can be carried out without the need to add a solvent that forms an azeotrope with the water produced during the reaction. Done.

B) Carboxylation step The carboxylation step is performed by simply blowing carbon dioxide into the reaction medium generated in the previous neutralization step, and at least 20 mol% of the starting hydrocarbon phenol is converted to a hydrocarbon salicylate (potentiometer). (Measured as salicylic acid). In order to avoid any decarboxylation of the alkyl salicylate formed, it must be carried out under pressure.

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

According to one variant, at least 25 mol% of the starting hydrocarbon phenol is converted to hydrocarbon salicylate using carbon dioxide at a temperature equal to or higher than 200 ° C. under a pressure of 4 × 10 ⁵ Pa (4 bar). Convert to

C) Filtration step The product of the carboxylation step may advantageously be filtered. The purpose of the filtration process is to remove sediment, particularly crystalline calcium carbonate, that may have been generated during the previous process and that can cause clogging of the filter attached to the lubricating oil circuit.

D) Separation step At least 10 mol% of the starting hydrocarbon phenol is separated from the product of the carboxylation step. It is preferred to carry out the separation using distillation. More preferably, the distillation is performed in a wiped (or rubbed) film evaporator at a temperature of about 150 ° C. to about 250 ° C. and a pressure of about 0.1 to about 4 mbar, more preferably about 190 ° C. to about It is carried out at a pressure of about 230 ° C., about 0.5 to about 3 mbar, most preferably about 195 ° C. to about 225 ° C., about 1 to about 2 mbar. At least 10 mol% of the starting hydrocarbon phenol is separated. More preferably, at least 30 mol% of the starting hydrocarbon phenol is separated. Most preferably, up to 55 mol% of the starting hydrocarbon phenol is separated. The separated hydrocarbon phenol can then be recycled and used as a starting material in a novel process or any other process.

[Cleaning and dispersing additive based on unsulfurized carboxylate-containing hydroxy-aromatic surfactant]
The characteristics of the detergent-dispersed additives based on hydroxy-aromatic surfactants containing unsulfurized carboxylates produced by the above method are much more alkaline earth metal than those produced by other routes. Its interesting composition includes aromatic ring hydrocarbon salicylates and low hydrocarbon phenols. When the hydrocarbon group is an alkyl group, the unsulfurized carboxylate-containing additive has the following composition:
(A) 40% or less alkylphenol,
(B) 10% to 50% alkaline earth metal alkylphenate; and (c) 15% to 60% alkaline earth metal monoaromatic alkyl salicylate.

  Unlike alkaline earth metal alkyl salicylates produced by other methods, the composition of this unsulfurized carboxylate-containing additive is that it contains only a small amount of alkaline earth metal diaromatic alkyl salicylates. It is in. The molar ratio of monoaromatic alkyl salicylate to diaromatic alkyl salicylate is at least 8: 1.

[Product characteristics by infrared spectroscopy]
In order to characterize the clean dispersion additive based on unsulfurized carboxylate-containing hydroxy-aromatic surfactants used in the present invention, out-of-plane aromatic ring vibration was used.

The infrared spectrum of the aromatic ring shows a transmission band of strong out-of-plane C—H bending vibration in the 675-870 cm ⁻¹ region, and 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, the transmission band occurs at 810-840 cm ⁻¹ .

Infrared spectra of reference chemical structures relevant to the present invention, out-of-plane C-H deformation vibration of transmittance band, ortho - 750 ± 3 cm ^-1 is alkylphenol, 760 ± 2 cm ^-1 in the salicylic acid and para - alkylphenol Shows that it occurs at 832 ± 3 cm ⁻¹ .

Alkaline earth alkyl phenates known in the art have infrared out-of-plane C—H bending vibration transmission bands at 750 ± 3 cm ⁻¹ and 832 ± 3 cm ⁻¹ . Alkaline earth alkyl salicylates known in the art have infrared out-of-plane C—H bending vibration transmission bands at 763 ± 3 cm ⁻¹ and 832 ± 3 cm ⁻¹ .

The undispersed carboxylate-containing hydroxy-aromatic surfactant-based cleaning dispersion additive used in the present invention is basically 763 ± 3 cm ⁻ , although there is other evidence that alkyl salicylates are present. ¹ shows no out-of-plane C-H bending vibration. This distinguishing feature has not been fully elucidated. However, it can be hypothesized that the special structure of a single aromatic ring alkyl salicylate somehow prevents this out-of-plane C—H bending vibration. In this structure, the carboxylic acid function is involved in the cyclic structure, thus increasing steric hindrance near the aromatic ring and limiting the free movement of adjacent hydrogen atoms. This hypothesis is due to the fact that the infrared spectrum of the acidified product (the carboxylic acid function is no longer involved in the ring structure and can therefore be rotated) has an out-of-plane C—H transmittance band at 763 ± 3 cm ^−1. Supported by.

Therefore, the features of the detergent dispersion additive based on hydroxy-aromatic surfactant containing unsulfurized carboxylate used in the present invention are characterized by an out-of-plane C—H bending vibration of about 763 ± 3 cm ⁻¹ and 832 ±. The ratio of the infrared transmittance band to the 3 cm 2 out-of-plane C—H bending vibration is 0.1: 1 or less.

  A clean dispersion additive based on a non-sulfurized carboxylate-containing hydroxy-aromatic surfactant produced by the above method meets the low sulfur requirements of LEDL, while not sulfurized, Provides improved high temperature deposit control performance over sulfurized products. Since this additive does not contain an alkali metal, it can be used as a cleaning dispersant in applications where the presence of the alkali metal has been proven to have a detrimental effect, such as marine engine oils.

[Cleaning and dispersing additive based on hydroxy-aromatic surfactant]
Cleaning and dispersing additives based on hydroxy-aromatic surfactants are well known in the art. Examples of such additives may include phenate, phenate-carboxylate, salicylate, carboxy-stearate, and the aforementioned unsulfurized carboxylate-containing additives.

[Manufacture of phenate]
The phenates that can be used in the present invention are generally hydrocarbon-substituted phenates in which the hydrocarbon substituent or group of substituents of the phenate is preferably one or more branched or unbranched alkyl groups. Suitable alkyl groups contain 4 to 50, preferably 9 to 28 carbon atoms. Particularly preferred alkyl groups are C ₁₂ groups derived from propylene tetramer. Hydrocarbon-substituted phenates are generally sulfided.

According to one preferred embodiment of the present invention, in the presence of diluent oil, glycol and halide ions, the glycol is present in a mixture with an alcohol having a boiling point of 150 ° C. or higher, and the sulfurized alkylphenol is converted to an alkaline earth base. By neutralizing with, removing alcohol, glycol, water and sediment, carbonating the reaction medium with CO ₂ in the presence of halide ions, and again removing alcohol, glycol, water and sediment. To produce an alkaline earth metal overbased sulfurized alkylphenate.

In another preferred embodiment, the overbased sulfurized hydrocarbon phenate is produced by a process comprising the following steps:
(A) Sulfurized alkylphenol is neutralized using an alkaline earth base in the presence of diluent oil, glycol and halide ions in the presence of a mixture with an alcohol having a boiling point of 150 ° C. or higher.
(B) removing alcohol, glycol and water from the medium, preferably by distillation;
(C) removing sediment from the medium, preferably by filtration;
(D) Carbonate the resulting medium with CO ₂ in the presence of halide ions; and (e) Remove alcohol, glycol and water from the medium, preferably by distillation.

Alkaline earth bases that can be used in the above method include barium, strontium and calcium oxides and hydroxides, particularly lime. Examples of alcohols having a boiling point of 150 ° C. or higher that can be used in this method include C _{6 to} C ₁₄ alcohols such as ethylhexanol, oxo alcohol, decyl alcohol, and tridecyl alcohol; alkoxy alcohols such as 2-butoxyethanol and 2-butoxypropanol And methyl ether of dipropylene glycol. As amines that can be used in this process, mention may be made of polyaminoalkanes, preferably polyaminoethanes, in particular ethylenediamine, and amino ethers, in particular tris (3-oxa-6-amino-hexyl) amine. Glycols that can be used in this process include alkylene glycols, especially ethylene glycol. The halide ions used in this process are preferably Cl ^- ions which can be added in the form of ammonium chloride or a metal chloride such as calcium chloride or zinc chloride.

  Diluent oils suitable for use in the above method include naphthenic oils and mixed oils, preferably paraffinic oils such as neutral 100 oil. The amount of diluent oil used is such that the amount of oil in the final product comprises from about 25% to about 65%, preferably from about 30% to about 50% by weight of the final product.

  The method outlined above is described in more detail in U.S. Pat. No. 4,514,313, the contents of which are also described herein.

[Production of phenate-carboxylate]
The phenate-carboxylates that can be used in the present invention are generally hydrocarbon-substituted phenate-carboxylates in which the hydrocarbon substituent or substituent group of the phenate is preferably one or more branched or unbranched alkyl groups. Rate. Suitable alkyl groups contain 4 to 50, preferably 9 to 28 carbon atoms. Particularly preferred alkyl groups are C ₁₂ groups derived from propylene tetramer. The hydrocarbon-substituted phenate-carboxylate may be sulfurized or not sulfurized.

  The overbased hydrocarbon phenate-carboxylate is prepared from an overbased hydrocarbon phenate that has been treated with a long chain carboxylic acid (preferably stearic acid), an anhydride or salt thereof, before, during or after overbasing. The method comprises a mixture of a hydrocarbon phenate, at least one solvent, a metal hydroxide, an aqueous metal chloride solution, and an alkyl polyhydric alcohol containing 1 to 5 carbon atoms with carbon dioxide under overbasing reaction conditions. Consisting of contact. Using an aqueous metal chloride solution instead of a solid metal chloride reduces the viscosity of the product. The metal is preferably an alkaline earth metal, most preferably calcium. The alkyl polyhydric alcohol is preferably ethylene glycol.

  In a preferred embodiment, the hydrocarbon phenate is overbased, and the phenate is treated with a long chain carboxylic acid (preferably stearic acid), an anhydride or salt thereof (before, during or after overbasing). A basic hydrocarbon phenate-carboxylate is prepared.

  In the overbasing step, a hydrocarbon phenate (which may be sulfurized or non-sulfurized), at least one solvent, a metal hydroxide, an aqueous metal chloride solution, and a polyalkyl containing 1 to 5 carbon atoms. A mixture of monohydric alcohols is reacted with carbon dioxide under overbasing reaction conditions. Overbasing reaction conditions include a temperature of 250 to 375 ° F. and approximately atmospheric pressure.

  The overbased hydrocarbon phenate is preferably a sulfurized alkyl phenate. The metal is preferably an alkaline earth metal, more preferably calcium. The alkyl polyhydric alcohol is preferably ethylene glycol.

  Carboxylate treatment (treatment with a long chain carboxylic acid, anhydride or salt thereof) can occur before, during or after the overbasing step. It is not critical when treatment with the long chain carboxylic acid, anhydride or salt thereof occurs in the context of the overbasing step.

  The phenate may or may not be sulfided. Preferably, the phenate is sulfided. If the phenate is sulfided, the sulfurization step can occur anytime prior to overbasing. More preferably, the phenate is sulfurized after the carboxylate treatment prior to the overbasing step.

  The method outlined above is described in more detail in US Pat. No. 5,942,476, the contents of which are also described herein.

[Manufacture of salicylates]
The manufacture of salicylates is well known in the art. Preferred salicylates that can be used in the present invention include medium and high overbased salicylates containing polyvalent or monovalent metals, more preferably monovalent metals, most preferably calcium salts. As used herein, medium overbasing (MOB) means that the TBN contains about 31-170 salicylates. High overbasing (HOB) means that the TBN contains about 171 to 400 salicylates. Ultra-high overbasing (HHOB) means that the TBN contains over 400 salicylates.

  In some embodiments, salicylates can be prepared by alkylation, carboxylation, and salt formation starting from, for example, phenol, ortho-alkylphenol, or para-alkylphenol. The alkylating agent preferably selected is an olefin or mixture of olefins having 12 or more carbon atoms in the molecule. Acid activated clays are suitable catalysts for the alkylation of phenol and ortho and para-alkylphenols. The amount of catalyst used is generally 1-10% by weight, in particular 3-7% by weight, based on the total weight of alkylating agent and alkylated phenol. The alkylation can be carried out at temperatures between 100 and 250 ° C, in particular between 125 and 225 ° C.

Alkylphenols prepared by the phenol or ortho- or para-alkylphenol route can be converted to the corresponding alkyl salicylic acid by techniques well known in the art. For example, the alkylphenol is converted to the corresponding alkylphenate with a caustic alcohol solution, and the latter is treated with CO ₂ at about 140 ° C. and a pressure of 10 to 30 atmospheres. Alkyl salicylic acid can be liberated from the alkyl salicylate thus obtained, for example with 30% sulfuric acid.

In the production of overbased salicylates, alkylsalicylic acid can be treated with an excess amount of metal compound, for example calcium in the form of Ca (OH) ₂ .

For example, an alkyl salicylic acid can be treated with 4 equivalents of calcium in the form of Ca (OH) ₂ while introducing 1.6 equivalents of CO ₂ .

  The production of medium and overbased salicylates is described in further detail in U.S. Pat. No. 4,810,398 and British Patent Nos. 1,146,925, 790473, and 786167, the contents of which are also incorporated herein.

[Production of carboxy-stearate]
The carboxy-stearate that can be used in the present invention is generally an alkaline earth metal monoaromatic hydrocarbon salicylate treated with a long chain carboxylic acid, anhydride or salt thereof.

  Carboxy-stearate is prepared from a mixture of an alkaline earth metal monoaromatic salicylate, at least one solvent and an alkaline earth metal hydroxide. The mixture is overbased by contacting the mixture with carbon dioxide in the presence of an alkyl polyhydric alcohol having 1 to 5 carbon atoms in the alkyl group of the alcohol. One such alkyl polyhydric alcohol that can be used is ethylene glycol.

  The method outlined above is described in more detail in US Pat. No. 6,348,438, the contents of which are also described herein.

[Base oil of lubricating viscosity]
The base oil of lubricating viscosity used in such a composition may be a mineral oil or a synthetic oil having a viscosity suitable for use in a crankcase of an internal combustion engine. Crankcase base oils typically have a viscosity of about 1300 cSt at 0 ° F. (−18 ° C.) to 3 cSt at 210 ° F. (99 ° C.). Base oils can be derived from synthetic or natural raw materials. Mineral oils used as base oils in the present invention can include paraffinic, naphthenic, and other oils commonly used in lubricating oil compositions. Synthetic oils can include both hydrocarbon synthetic oils and synthetic esters. Synthetic hydrocarbon oils that can be used include liquid polymers of alpha olefins with the proper viscosity. Particularly useful are hydrogenated liquid oligomers of C ₆ -C ₁₂ alpha olefins such as 1-decene trimer. Similarly, alkylbenzenes of the proper viscosity, such as didodecylbenzene, can be used. Synthetic esters that can be used include esters of monocarboxylic and polycarboxylic acids with monohydroxyalkanols and polyols. Representative examples include didodecyl adipate, pentaerythritol tetracaproate, di-2-ethylhexyl adipate, and dilauryl sebacate. Complex esters synthesized from mixtures of mono and dicarboxylic acids and mono and dihydroxy alkanols can also be used.

  A blend of mineral and synthetic oils is also useful. For example, a blend of 10 to 25% hydrogenated 1-decene trimer and 75 to 90% 150 SUS (100 ° F.) mineral oil makes an excellent lubricant base.

  The LEDL of the present invention can be added to one, two, three or four base oil raw materials or combinations thereof.

[Cleaning agent]
The LEDL of the present invention has been found to improve internal oxidation and corrosion inhibition performance when contacted with an internal combustion engine. LEDL embodiments may contain a detergent.

  The detergent helps to suppress varnish, ring zone deposits and rust by retaining insoluble particles in the colloidal suspension. Metal-containing (or ash generating) detergents function as deposit control detergents, or as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and reducing engine life. extend. The detergent generally comprises a polar head with a long hydrophobic tail, which consists of a metal salt of an acidic organic compound. The salt can include a substantially stoichiometric amount of metal. In that case, the salt is usually considered a normal or neutral salt, and generally has a total base number of 0 to 10 (as measured by ASTM D2896). It is also possible to produce an overbased detergent by reacting an excess metal compound such as an oxide or hydroxide with an acidic gas such as carbon dioxide to include a large amount of metal base. The total base number of such overbased detergents is about 15 to 30 (low overbased “LOB”), about 31 to 170 (medium overbased “MOB”), about 171 to 400 (high overbased). Or “above 400” (super-high overbased “HHOB”).

[Dispersant]
The LEDL of the present invention comprises one or more nitrogen-containing dispersants of the type generally represented by succinimide (eg, polyisobutylene succinic acid anhydride (PIBSA) -polyamine having a PIBSA molecular weight of about 700 to 2500). You may contain a dispersing agent. The dispersant may be borated or not borated, and may be ashless or ash-containing. The lubricating oil of the present invention can contain from about 1% to about 12% by weight or more of a dispersant.

  Preferred dispersants in the present invention comprise one or more dispersants having an average molecular weight (mw) of about 1000 to about 10,000. Dispersants made from polyisobutylene (PIB) having an mw of about 1000 to about 5000 are such preferred dispersants.

  A preferred dispersant of the present invention may be one or more succinimides. “Succinimide” is construed in the art to include a number of amides, imides, and the like that are formed by the reaction of succinic anhydride with an amine, and is used as such herein. However, the main product is succinimide, which term is generally taken to mean the product of the reaction of an alkenyl or alkyl substituted succinic acid or anhydride with a polyamine. Alkenyl or alkyl succinimides are disclosed in numerous references and are well known in the art. For a basic class of succinimides and related substances included in the technical term “succinimide”, see US Pat. No. 3219666, No. 3272746, No. 3361673, No. 3381022, No. 3912764, No. 4234435, No. 4612132, No. 4747965, No. 5112507, No. 5226603, No. 5266186, No. 5286799, No. 5319030, No. 5334321, No. 5356552, No. 5716912, the disclosure content of which is also described herein.

  The present invention can contain one or more succinimides, which can be mono, poly or bis-succinimides. The present invention may comprise a lubricating oil containing one or more succinimides that are post-treated or not post-treated.

  The borated dispersant that can be used in the present invention can be derived from the reaction product of polyisobutenyl succinic anhydride and polyamine. The borated dispersant is preferably derived from polybutene having a molecular weight of 1200 to 1400, most preferably about 1300.

The ethylene carbonate treated or EC treated dispersant that can be used in the present invention can be derived from the reaction product of polyisobutenyl succinic anhydride and polyamine. The number average molecular weight (M _n ) of the polyisobutene is at least 1800. The EC-treated dispersant is preferably a polybutene succinimide derived from a polybutene having a molecular weight of 2000 to 2400. Preferred EC-treated succinimides of the present invention are described in US Pat. Nos. 5,334,321 and 5,356,552.

[Corrosion inhibitor]
Corrosion inhibitors that can be advantageously used in the LEDL of the present invention are, for example, one or more aromatic dicarboxylic acid succinimide salts and dispersible aromatic dicarboxylic acid corrosion inhibitors. Preferred aromatic dicarboxylic acids consist of one or more terephthalic acids.

  Certain corrosion inhibitors including dispersible aromatic dicarboxylic acid corrosion inhibitors are described, for example, in U.S. Pat. Nos. 3,287,271, 3,692,681, and 3,374,174, all of which are described herein. And

  One embodiment of the dispersible aromatic dicarboxylic acid corrosion inhibitor includes a polyisobutenyl succinic anhydride (PIBSA) having a molecular weight of about 1100 to about 1500, preferably about 1300, and one or more polyamines, preferably one or more. Heavy polyamines (HPA) can be synthesized by reacting with an amine / PIBSA CMR of about 0.4 to about 0.6, preferably about 0.45. This produces a reaction product that can then react with terephthalic acid.

  Another embodiment of the dispersible aromatic dicarboxylic acid corrosion inhibitor of the present invention can be synthesized as follows. One or more PIBSA and one or more polyamines, with or without the use of a mixture thereof, at a temperature of about 110 ° C. to about 200 ° C., preferably about 150 ° C. to about 170 ° C. for 1 to 20 hours One or more succinimides can be produced by reaction by heating. Heating for about 3 to about 6 hours is preferred. Heat after mixing the reactants, or heat while mixing the reactants. During the heating period, the water of reaction may be removed by any means known in the art. Any PIBSA can be used. There may be mentioned thermal PIBSA, chlorinated PIBSA, a mixture of thermal and chlorinated PIBSA, sulfonic acid catalyzed PIBSA, polyPIBSA, or terpolymer PIBSA made from conventional or highly reactive PIB. Mixtures of PIBSA and copolymers can also be used. An amine / PIBSA loading molar ratio (CMR) of about 0.4 to 0.6 can be used. A preferred CMR is from about 0.4 to about 0.5. After heating, the reaction mixture may be cooled to about 110 ° C to about 150 ° C, preferably about 130 ° C to about 135 ° C. Then terephthalic acid may be added. From about 2% to about 5%, preferably from about 2.5% to about 3.5% by weight of terephthalic acid can be used, based on the weight of succinimide. The mixture may then be heated for about 1 to about 10 hours, preferably about 2 to about 4 hours. The mixture may then be filtered. Another aspect of the invention is the synthesis of 1000 molecular weight polyisobutene succinic anhydride (PIBSA) and tetraethylenepentamine (TEPA) using a amine / PIBSA loading molar ratio (CMR) of 0.71. And may contain one or more corrosion inhibitors. This produces a reaction product that can then react with terephthalic acid to produce a dispersible aromatic dicarboxylic acid corrosion inhibitor.

  The production of the corrosion inhibitor is further described, for example, in US patent application Ser. No. 10/367432, filed on Feb. 14, 2003, the entire contents of which are described herein.

[Antiwear agent]
Conventional antiwear agents can be used in the present invention. As the name implies, this agent reduces wear on moving metal parts. Examples of such agents include, but are not limited to, phosphate esters, phosphites, carbamates, esters, sulfur-containing compounds, and molybdenum complexes. The LEDL of the present invention may contain one or more antiwear agents such as metal dithione phosphate and metal dithiocarbamate, or mixtures thereof.

[Other additive components]
The following additive components are some examples of components that can be preferably used in the present invention. Examples of these additives are provided to illustrate the present invention and are not intended to limit the present invention.

(1) Ashless dispersant: alkenyl succinimide, alkenyl succinimide modified with other organic compounds, alkenyl succinimide modified with boric acid, alkenyl succinate, EC-treated dispersant.

(2) Antioxidant:
(A) Phenol type antioxidant: 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4′- Bis (2-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4 , 4'-isopropylidenebis (2,6-di-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-nonylphenol), 2,2'-isobutylidenebis (4,6-dimethyl) Phenol), 2,2′-methylenebis (4-methyl-6-cyclohexylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-4- (N, N'-dimethylaminomethylphenol), 4,4'-thiobis (2-methyl-6-tert- Butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide, and bis (3,5-di-tert) -Butyl-4-hydroxybenzyl).
(B) Diphenylamine type antioxidants: alkylated diphenylamine, phenyl-alpha-naphthylamine, and alkylated alpha-naphthylamine.
(C) Other types: metal dithiocarbamates (eg, zinc dithiocarbamate), molybdenum oxysulfide succinimide complexes, and methylenebis (dibutyldithiocarbamate).

(3) Rust prevention additive (rust prevention agent)
(A) 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.
(B) Other compounds: stearic acid and other fatty acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, partial carboxylic acid esters of polyhydric alcohols, and phosphate esters.

(4) Demulsifier: adduct of alkylphenol and ethylene oxide, polyoxyethylene alkyl ether, and polyoxyethylene sorbitan ester.

(5) Extreme pressure agent (EP agent): zinc dialkyldithiophosphate (aryl zinc, primary alkyl and secondary alkyl type), sulfurized oil, diphenyl sulfide, methyltrichlorostearate, chlorinated naphthalene, fluoroalkylpolysiloxane , And lead naphthenate.

(6) Friction modifier: fatty alcohol, fatty acid, amine, borated ester, and other esters.

(7) Multifunctional additives: sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum organophosphorus dithioate, oxymolybdenum monoglyceride, oxymolybdenum diethylate amide, amine-molybdenum complex compound, and sulfur-containing molybdenum complex compound.

(8) Viscosity index improver: polymethacrylate type polymer, ethylene-propylene copolymer, styrene-isoprene copolymer, hydrated styrene-isoprene copolymer, polyisobutylene, and dispersant type viscosity index improver.

(9) Pour point depressant: polymethyl methacrylate.

(10) Antifoaming agent: alkyl methacrylate polymer and dimethyl silicone polymer.

(11) Metal detergents: sulfurized or unsulfurized alkyl or alkenyl phenates, alkyl or alkenyl aromatic sulfonates, calcium sulfonates, sulfurized or unsulfurized metal salts of polyhydroxyalkyl or alkenyl aromatic compounds, alkyl or alkenyl hydroxy aromatic sulfonates. , Sulfurized or unsulfurized alkyl or alkenyl naphthenates, metal salts of alkanolic acids, metal salts of alkyl or alkenyl polyacids, and chemical and physical mixtures thereof.

[Low emission diesel lubricating oil composition]
The LEDL of the present invention is useful because of its improved cleanliness over other engine lubricating oil compositions. Such lubricating oil compositions comprise a major amount of a base oil of lubricating viscosity and about 0% to about 1.2% ash, about 0.1% to about 0.5% sulfur, and From about 0.02 wt% to about 0.1 wt% phosphorus. The LEDL provides improved compatibility with exhaust gas aftertreatment devices while improving cleanliness.

In some embodiments, the LEDL includes the following components:
(A) a major amount of base oil of lubricating viscosity;
(B) 0% to 1.2% by weight of ash,
(C) 0.05% to 0.5% by weight of sulfur,
(D) 0.02% to 0.1% by weight phosphorus,
(E) 1% to 12% of at least one dispersant,
(F) 0.5% to 1.1% of at least one zinc dithiophosphate;
(G) 0% to 2.5% of at least one antioxidant,
(H) 0% to 1% of at least one antifoaming agent,
(I) 0% to 10% of at least one viscosity index improver, and (j) 0% to 0.5% of a corrosion inhibitor.

  In another aspect, the LEDL of the present invention comprises a detergent dispersion based on the above components and from about 1.8% to about 5.5% by weight of the unsulfurized carboxylate-containing hydroxy-aromatic surfactant of the present invention. And additives. LEDL containing the additive has been found to provide better corrosion protection than LEDL containing commercial salicylates at certain ash, sulfur and phosphorus levels.

  It has been found that the LEDL of the present invention can be manufactured to contain a very small amount of sulfur. A very small amount of sulfur is defined to mean about 0.05 wt.% To about 0.3 wt.% Sulfur. Surprisingly, the LEDL with very low sulfur produced according to the present invention provides excellent corrosion protection when used in internal combustion engines.

  In another aspect, LEDL is produced by blending a mixture of the above components. The LEDL produced by that method may have a slightly different composition than the initial mixture because the components can interact. The components can be blended in any order and can be blended as a combination of components.

  The invention is further illustrated by the following examples, which illustrate particularly advantageous process embodiments. In addition, an Example is described in order to demonstrate this invention, Comprising: This invention is not limited by it.

[Example 1]
(Production of unsulfurized carboxylate-containing hydroxy-aromatic surfactant-based detergent dispersion additive)
An intermediate product was prepared according to the method described in US Pat. No. 6,162,770. The method is reproduced here.

A) Neutralization 875 g of branched-chain dodecylphenol (DDP) with a molecular mass of 270 (ie 3.24 mol) and 875 g of linear alkylphenol with a molecular mass of about 390 (ie 2.24 mol) with a thermal insulation at the top A 4-liter four-necked glass reactor equipped with a Vigreux fractionator was packed. The isomeric molar redistribution of para to orthoalkylphenol was as follows:
DDP: Para 89% and ortho 5.5%
Linear alkylphenols: para 39% and ortho 53%

The stirrer is started, the reaction mixture is heated to 65 ° C. and at that temperature 158 grams of slaked lime Ca (OH) ₂ (ie 2.135 mol) and 19 g of a mixture of formic acid and acetic acid (50/50 by weight) are added. Added.

  The reaction medium was further heated to 120 ° C., at which temperature the reactor was placed under a nitrogen atmosphere and then heated to 165 ° C. before the introduction of nitrogen was stopped. Distillation of water began at this temperature.

  The temperature was raised to 240 ° C. and the pressure was gradually lowered from atmospheric pressure to obtain an absolute pressure of 5000 Pa (50 mbars).

The reaction mixture was maintained for 5 hours under the previous conditions. After cooling the reaction mixture to 180 ° C., the vacuum was turned off under a nitrogen atmosphere and a sample was taken for analysis. The total amount of distillate obtained was about 120 cm ³ and separation occurred in the lower layer (66 cm ³ was water).

B) Carboxylation The product obtained in step (A) was transferred to a 3.6 liter autoclave and heated to 180 ° C.

At this temperature carbon dioxide (CO ₂ ) was used to begin scavenging the reactor and continued for 10 minutes. The amount of CO ₂ used at this stage was about 20 grams.

After raising the temperature to 200 ° C., the autoclave was closed leaving a very small leak and the introduction of CO ₂ was continued, maintaining a pressure of 3.5 × 10 ⁵ Pa (3.5 bar) at 200 ° C. for 5 hours. did. The amount of CO ₂ introduced was about 50 grams. After cooling the autoclave to 165 ° C., the pressure was returned to atmospheric pressure and the reactor was purged with nitrogen.

  A total of 1912 grams of product was recovered prior to filtration. The product was then filtered.

  The above process was extended to a 6000 gallon reactor to produce an intermediate product. The intermediate product was then subjected to further distillation steps outlined below.

The analysis results for the 6000 gallon batch of intermediate product were as follows:
TBN 116mgKOH / gm
Calcium 4.1 wt%
Salicylic acid index (SAI) 40mgKOH / gm

  SAI is a measure of the amount of alkyl salicylate produced in the cleaning dispersant. The measured value was obtained by acidifying the product with a strong acid (hydrochloric acid) in the presence of diethyl ether and then by potentiometric titration (using tetra n-butylammonium hydroxide as a titrant). . The results were expressed as equivalent mgKOH (base number unit) per gram of product.

C) Distillation The intermediate product was fed to a rubbed film evaporator (WFE) having a surface area of 0.39 m ² at a rate of 70 kg / hr. The WFE had a mobile separator with an internal cooler and a hot oil jacket. The hot oil temperature of the jacket was about 250 ° C. The pressure in WFE was 1.3 mbar. The feed temperature to WFE was 135 ° C. The final product temperature leaving WFE was 222 ° C. The product was cooled below 100 ° C. before dilution with 100N base oil. Approximately 47.5% (by weight) of the feed to WFE was collected as distillate. The amount of distillate collected can vary from 10% to about 55% by weight of the feed to the WFE. Then, depending on the level of distillation, a sufficient amount of organic diluent is added to the distilled product to provide a manageable viscosity. As the weight percent of feed collected as distillate increases, the amount of diluent required to be added to the distilled product to achieve a manageable viscosity also increases.

The analytical results of the distilled product were as follows:
TBN 174mgKOH / gm
Ca 6.09 wt%
Salicylic acid index (SAI) 58
100 ° C viscosity 705 cSt
Oil content (in mass balance) 21.5% by weight

  It is well known in the art that salicylate structures are thermally unstable. Since the distilled material had a salicylic acid index-to-calcium ratio similar to the feedstock, no decomposition of the salicylate structure occurred even though the feed was exposed to relatively high temperatures. Decomposition did not occur because the residence time in WFE was relatively short. The appearance of the distillate was clear and slightly yellowish, similar to the appearance of the starting hydrocarbon phenol introduced in the neutralization step. The TBN content of the distillate was virtually zero, indicating that no feed to the distillation process was carried over to the distillate. The distillate was analyzed by gas chromatography and found to contain approximately 61% branched chain hydrocarbon phenol, 39% linear hydrocarbon phenol, and 6% 100N base oil.

[Example 2]
The predistilled product produced according to Example 1 was distilled with the above WFE under various conditions. Table 1 shows typical results under other distillation conditions.

Table 1
───────────────────────────────
1 2
───────────────────────────────
WFE conditions:
Supply speed (kg / hr) 122 86
Pressure (mbar) 1.44 1.5
Hot oil temperature (° C) 235 254
───────────────────────────────
Product temperature leaving the evaporator (° C) 205 222
───────────────────────────────
Amount of distillate (% by weight) ¹ 30 43
───────────────────────────────
Oil (wt%) in the final product 0 14.5
───────────────────────────────
Product analysis results TBN (mgKOH / gm) 166 174
Ca (weight%) 5.92 6.2
SAI (mgKOH / gm) 57 59
100 ° C viscosity (cSt) 226 575
───────────────────────────────
Distillate composition Branched chain alkylphenol (wt%) 76 64
Linear alkylphenol (wt%) 15 27
100N base oil (wt%) 9 9
───────────────────────────────
1: Based on WFE supply speed

[Example 3]
Example 1 was repeated except for the following changes:
a) The surface area of WFE was 0.78 m ² b) The feed rate to WFE was about 135 kg / hr c) The final distillation product was diluted with about 36 wt% 100 N oil to facilitate handling Of product was produced. As in Example 1, approximately 46% (by weight) of the feed to the evaporator was collected as distillate.

The analysis results for this product are as follows:
TBN 138mgKOH / gm
Calcium 4.96% by weight
SAI 47mgKOH / gm

  About 15 gm of the product of Example 3 was dialyzed for about 24 hours using a Soxhlet extractor (solvent pentane) and a latex thin film condom, and the dialysate fraction (substance passed through the thin film) and the residual fraction (Substance remaining in the latex thin film bag).

  From the dialysate fraction of the dialysis operation, fraction 1 was first obtained using 12 mL of hexane using silica gel chromatography (two silica gel cartridges—0.2-0.25 gm with Waters part number 051900). The cartridge was then inverted and flushed with 12 mL of 80:20 ethyl acetate: ethanol to obtain fraction 2, which was separated into two fractions. Fraction 1 was composed of diluent oil and fraction 2 was composed of free alkylphenol.

  Fraction 2 obtained by the chromatographic separation was analyzed using supercritical chromatography (SFC) to determine the amount of branched and linear alkylphenol present. Quantification was performed using a calibration curve of a known mixture of branched and linear alkylphenols.

After acidifying the product with a strong acid (hydrochloric acid) in the presence of diethyl ether, potentiometric titration (using tetra n-butylammonium hydroxide as a titrant) was performed on the organic fraction, and the dialysis residue. The% SA was determined for the fraction. In this method, alkyl salicylic acid and remaining alkylphenol (non-carboxylated alkylphenate) are separated and quantified. The results were expressed as equivalent mgKOH (base number unit) per gram of product. % SA was then determined by using the following formula:
% SA = 100 ^* (alkyl salicylic acid /
(Alkylphenol + alkylsalicylic acid))

  % Ca of the residue was determined by old-style X-ray spectroscopy.

The dialysis results are as follows:
Dialysate 51.1% by weight of starting sample weight
Residue 48.9% by weight of starting sample
Dialysate composition:
Dodecylphenol 1.0% by weight
Linear alkylphenol 26.7% by weight
100N base oil 72.3% by weight
Residue composition:
Calcium 9.3% by weight
TBN 259mgKOH / gm
SAI 78mgKOH / gm
% SA 50

The following composition of the product produced in Example 3 was calculated from the composition of the dialysate fraction and the residue fraction:
Total alkylphenol content 14.1% by weight
Oil 36.9% by weight
Monoaromatic alkyl salicylate 24.5% by weight
Calcium alkyl phenate 24.5% by weight

(Performance test method)
The following sections describe the performance test methods associated with these examples.

(Corrosion inhibition (ASTM D6594-1))
This is a standard test method for evaluating the corrosivity of diesel engine oil at 135 ° C. This test has been used to test lubricants to determine the tendency of diesel engine lubricants to corrode various metals, particularly lead and copper alloys commonly used in cam followers and bearings. Four metal samples of copper, lead, tin and phosphor bronze were immersed in a measured amount of engine oil. Air was blown into the hot oil for a period of time. After the test was completed, each copper sample and fatigued oil were examined to detect corrosion and corrosion products.

(Example showing performance advantages)
The following examples illustrate the performance advantages demonstrated by the LEDL of the present invention.

[Example 4]
(Automobile performance)
The lubricating oil formulation used in this example was designed for a low emission diesel lubricant (LEDL) intended for use in a low emission diesel engine and had the following composition:

  Three sets of LEDL formulations were produced, each set having the same level of ash, sulfur and phosphorus. Corrosion performance for each set of formulations with LEDL containing a clean dispersion additive based on a hydroxy-aromatic surfactant containing unsulfurized carboxylate used in the present invention and an LEDL containing a commercially available salicylate A comparison was made. In each case, the LEDL of the present invention containing the carboxylate-containing additive demonstrated excellent corrosion inhibition performance. Surprisingly, acceptable performance was obtained even with very low sulfur levels.

[Example 5]
(Automobile performance)
The lubricating oil formulation used in this example was designed for a low emission diesel lubricant (LEDL) intended for use in a low emission diesel engine and had the following composition:

  In each LEDL over a range of sulfur, phosphorus and ash levels, the LEDL exhibited excellent corrosion inhibition performance. The performance is not reduced by reducing the weight percent of ZnDTP. Even with a very small amount of sulfur, the LEDL of the present invention exhibited excellent corrosion inhibition performance.

[Example 6]
(Manufacture of LEDL with very small amount of sulfur)
In combination with 3.2 mmol ZnDTP with the following components:
1% to 4% by weight borated dispersant,
3% to 8% by weight of non-borated dispersant,
4-8 mmol of LOBCa-sulfonate,
0 wt% to 0.5 wt% corrosion inhibitor,
0.1 wt% to 0.5 wt% molybdenum antioxidant,
0% to 1% by weight of a phenolic antioxidant,
0.1 wt% to 1 wt% amine antioxidant,
0% to 6% by weight of an olefin copolymer viscosity index improver,
0-25 ppm defoamer, and 1.8-5.5 wt% unsulfurized carboxylate-containing hydroxy-aromatic surfactant based detergent dispersant,
And LEDL containing 0.02 weight% of phosphorus and 0.06 weight% of sulfur was manufactured.

While this invention has been described in connection with specific embodiments, this application is intended to cover those various changes and substitutions that may be made by those skilled in the art without departing from the spirit and scope of the appended claims. It is.

Claims (25)

Ash content is in the range of 0% to 1.2% by weight, sulfur content is in the range of 0.1% to 0.5% by weight, and phosphorus content is 0.02% to A low emission diesel lubricant composition in the range of 0.1% by weight and containing the following components:
A base oil with a major amount of lubricating viscosity,
Dispersant,
Antiwear agents, and
1.8% to 5.5% by weight of an unsulfurized carboxylate-containing additive produced by a process comprising the following steps:
(A) neutralizing the hydrocarbon phenol with an alkaline earth base in the presence of an accelerator to produce a hydrocarbon phenate;
(B) carboxylating the hydrocarbon phenate obtained in step (a) with carbon dioxide under carboxylation conditions sufficient to convert at least 20 mol% of the starting hydrocarbon phenol to a hydrocarbon salicylate. And
(C) separating the hydrocarbon phenol from the product produced in step (b) in an amount corresponding to at least 10% by weight of the amount of the starting hydrocarbon phenol to produce the additive. The hydrocarbon salicylate comprises a monoaromatic hydrocarbon salicylate and a diaromatic hydrocarbon salicylate, and the molar ratio of the monoaromatic hydrocarbon salicylate to the diaromatic hydrocarbon salicylate is at least 8: 1. Item 2. The low emission diesel lubricant composition according to Item 1. 2. In step (c), the hydrocarbon phenol is separated from the product produced in step (b) in an amount corresponding to at least 30% by weight of the amount of starting hydrocarbon phenol to produce the additive. The low emission diesel lubricant composition as described. In the step (c), the hydrocarbon phenol is separated from the product produced in the step (b) in an amount corresponding to 55% by mass or less of the amount of the starting hydrocarbon phenol to produce the additive. The low emission diesel lubricant composition as described. Claim that in step (c), the hydrocarbon phenol is separated from the product produced in step (b) in an amount corresponding to 45% to 50% by weight of the amount of the starting hydrocarbon phenol to produce the additive. Item 2. The low emission diesel lubricant composition according to Item 1. The low emission diesel lubricant composition according to claim 1, wherein in the step (c), the hydrocarbon phenol is removed by distillation. The low-emission diesel lubricant composition according to claim 6, wherein the distillation is performed by falling film type distillation, wiping film type evaporator distillation or short path type distillation. The low emission diesel lubricant composition according to claim 6 or 7, wherein the distillation is carried out at a temperature in the range of 150 ° C to 250 ° C and a pressure of 0.1 to 4 mbar. The low emission diesel lubricant composition according to claim 6 or 7, wherein the distillation is carried out at a temperature in the range of 190 ° C to 230 ° C and a pressure of 0.5 to 3 mbar. The low emission diesel lubricant composition according to claim 6 or 7, wherein the distillation is carried out at a temperature in the range of 195 ° C to 225 ° C and a pressure of 1 to 2 mbar. The low emission diesel lubricant composition of claim 1, wherein the additive comprises an organic diluent. The low emission diesel lubricant composition according to claim 1, wherein step (a) is performed under the following conditions:
(A) performing the neutralization operation in the presence of at least one carboxylic acid containing 1 to 4 carbon atoms and in the absence of alkali bases, dialcohols and monoalcohols; and
(B) performing the neutralization operation at a temperature of at least 200 ° C.
  (C) in order to remove the water of reaction, the pressure is gradually reduced below atmospheric pressure without the presence of any solvent capable of forming an azeotrope with water,
(D) the hydrocarbon phenol comprises a mixture of up to 85% linear hydrocarbon phenol and at least 15% branched hydrocarbon phenol in which the branched hydrocarbon group contains at least 9 carbon atoms; and
(E) The amount of reagent used corresponds to the following molar ratio:
(1) an alkaline earth base / hydrocarbon phenol molar ratio of 0.2: 1 to 0.7: 1; and
(2) The molar ratio of carboxylic acid / hydrocarbon phenol is 0.01: 1 to 0.5: 1. The low emission diesel lubricant composition of claim 1 further comprising a corrosion inhibitor. The low emission diesel lubricant composition of claim 1, wherein the dispersant is a borated dispersant and the antiwear agent is a metal salt of dithiophosphate. The dispersant is 1.0% to 4.0% by weight borated dispersant based on the amount of the lubricating oil composition, and the antiwear agent is 0.2% based on the amount of the lubricating oil composition. The low-emission diesel lubricant composition according to claim 1, wherein the low-emission diesel lubricant composition is contained in an amount of 1 to 1.1 mass% and further contains 0 to 0.5 mass% of a corrosion inhibitor. The low emission diesel lubricant composition of claim 15, wherein the borated dispersant is borated succinimide, the antiwear agent is zinc dithiophosphate, and the corrosion inhibitor is a terephthalic acid imide salt. object. The low emission diesel lubricant composition of claim 16, further comprising:
3.0 wt% to 8.0 wt% non-borated dispersant,
0.6% to 1.4% by weight of calcium sulfonate,
0.1 wt% to 0.5 wt% molybdenum antioxidant,
0% to 1.0% by weight of a phenolic antioxidant,
0.1 mass% to 1.0 mass% amine-based antioxidant,
0 wt% to 6.0 wt% dispersant olefin copolymer, and
0-25 ppm defoamer. Low emission diesel lubricant composition having an ash content of 1.0% by mass or less, a sulfur content of 0.3% by mass or less, and a phosphorus content of 0.08% by mass or less, containing the following components: :
A base oil with a major amount of lubricating viscosity,
Dispersant,
Antiwear agents, and
1.8% to 5.5% by weight of an unsulfurized carboxylate-containing additive produced by a process comprising the following steps:
(A) neutralizing the hydrocarbon phenol with an alkaline earth base in the presence of an accelerator to produce a hydrocarbon phenate;
(B) carboxylating the hydrocarbon phenate obtained in step (a) with carbon dioxide under carboxylation conditions sufficient to convert at least 20 mol% of the starting hydrocarbon phenol to a hydrocarbon salicylate. And
(C) separating the hydrocarbon phenol from the product produced in step (b) in an amount corresponding to at least 10% by weight of the amount of the starting hydrocarbon phenol to produce the additive. The low emission diesel lubricant composition of claim 18 further comprising a corrosion inhibitor. The low emission diesel lubricant composition of claim 18, wherein the dispersant is a borated dispersant and the antiwear agent is a metal salt of dithiophosphate. The dispersant is 1.0% to 4.0% by weight borated dispersant based on the amount of the lubricating oil composition, and the antiwear agent is 0.2% based on the amount of the lubricating oil composition. The low-emission diesel lubricant composition according to claim 18, wherein the low-emission diesel lubricant composition is contained by mass% to 1.1 mass%, and further contains 0 mass% to 0.5 mass% corrosion inhibitor. The low emission diesel lubricant composition of claim 21, wherein the borated dispersant is borated succinimide, the antiwear agent is zinc dithiophosphate, and the corrosion inhibitor is a terephthalic acid imide salt. object. The low emission diesel lubricant composition of claim 22 further comprising:
3.0 wt% to 8.0 wt% non-borated dispersant,
0.6% to 1.4% by weight of calcium sulfonate,
0.1 wt% to 0.5 wt% molybdenum antioxidant,
0% to 1.0% by weight of a phenolic antioxidant,
0.1 mass% to 1.0 mass% amine-based antioxidant,
0 wt% to 6.0 wt% dispersant olefin copolymer, and
0-25 ppm defoamer. Ash content is in the range of 0.4 wt% to 1.0 wt%, sulfur content is in the range of 0.05 wt% to 0.3 wt%, and phosphorus content is 0.02 wt% The low emission diesel lubricant composition according to claim 18, which is in the range of 0.08 mass%. 25. A low emission diesel lubricant composition according to claim 24, wherein the sulfur content is in the range of 0.05 wt% to 0.15 wt%.