JPH03153794A - Perbasic additive for lubricating oil, containing copper compound or copper and boron compounds, its manufacture, and composition containing the additive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overbased additive for lubricating oils containing a copper compound or a compound of copper and boron, a process for producing the same, and a composition containing the additive.

Overbased additives are alkali metal or alkaline earth metal salts of organic acids that become overbased upon carbonation with carbon dioxide. The term "overbased" is used to describe an excess of alkali metal or alkaline earth metal relative to the stoichiometric amount required to neutralize the organic acid used.

Overbased additives have the structure of a colloidal dispersion in which the alkali metal or alkaline earth metal carbonates formed during carbonation are contained in micelles. The micelles are stabilized by alkali metal or alkaline earth metal salts of organic acids that have a cleaning effect.

Salts of organic acids used in overbased additives are generally sulfonates, salicylates, or sulfur-containing phenolates, each of which is described in U.S. Pat. No. 4.606.2.
No. 16, European Patent Publication No. 279.493 and French Patent No. 2.105.494.

These overbased additives are particularly useful in "gasoline" or "diesel" type internal combustion engine lubricating oils.

They have a cleaning and dispersing effect, thus preventing the formation of lacquers and varnishes and keeping soot caused by incomplete combustion of the fuel dispersed.

Another important function of these additives is to neutralize acid compounds such as organic acids produced by the oxidation of the oil as well as sulfur-containing compounds introduced by the fuel.

This neutralization function is particularly valuable when using sulfur-rich fuels such as heavy oil used in marine engines.

Certain overbased additives (especially overbased sulfonic acids)
have the disadvantage of considerably reducing the antioxidant capacity of lubricant formulations.

By using the additive of the present invention, it is possible to prevent the above-mentioned decline in antioxidant ability and even improve the oxidation resistance of lubricating oil.

Polyvalent metals such as copper, molybdenum, iron and cobalt affect oil oxidation. For example, copper catalyzes the oxidation of lubricating oils at concentrations below 50 ppm. In contrast, at concentrations of 50 to 500 ppm, copper has an oxidation-inhibiting effect.

European Patent Application No. 0.024.146 describes formulations containing such concentrations of copper in the form of cupric oleate.

US Pat. No. 4,715,974 describes the use of copper salts of sulfurized unsaturated fatty acids in lubricating oils. US Pat. No. 4,770,799 describes copper salts of succinic esters of substituted phenols.

Copper compounds have also been used in combination with amines, which accelerate the decomposition of peroxides.

Such a combination of copper salts and amines is disclosed in U.S. Pat. No. 3.093.
．． No. 585, No. 3.634.238, No. 4, 11
No. 0.234 and No. 4.122.033.

Oil-soluble copper salts such as copper oleate cannot be used in overbased additives. It is not possible to make a reaction mixture containing copper oleate overbased, and adding copper oleate to an overbased additive gives an unstable mixture.

European Patent Application No. 0.225.580 describes the incorporation of hydrocarbon-insoluble copper carboxylates with a total number of carbon atoms of up to 6 into overbased additives. These hydrocarbon-insoluble copper carboxylates, as well as alkali metal or alkaline earth metal carbonates (most often calcium carbonate), are found inside the micelles of colloidal dispersions. In order for such a micellar dispersion of calcium carbonate and copper carboxylate to be stable, a significant amount of detergent must be present.

We have now discovered that medium chain length copper carboxylates with detergent effects can be incorporated into overbased additives. These carboxylates, similar to alkali metals or alkali metal salts of organic acids that have been commonly used in overbased additives as detergents, do not enter the interior of the micelles but remain at the interface and help stabilize the micelles. Contribute.

The present invention provides an overbased additive for lubricating oils comprising an alkali metal or alkaline earth metal carbonate dispersed in a diluent oil by the action of a detergent mixture, the mixture being a linear or branched C7 The present invention relates to an additive characterized by containing at least one type of copper carboxylate obtained from CIO to CIO aliphatic carboxylic acids.

These C7 to CIO aliphatic carboxylic acid coppers are only partially soluble in hydrocarbons, but sufficiently soluble to pass through a dialysis membrane. However, the additive obtained after removing promoter, solvent, and solid residue is not dialyzed through a dialysis membrane. This demonstrates that the copper carboxylate is present as part of the micelle rather than as a free molecule.

Electron microscopy confirmed the presence of micelles with a diameter of 5 to 10 nffl. Medium chain length copper carboxylates from C7 to CIO form part of this micelle and contribute to its stability through its purifying effect. At the same time, the presence of copper gives this additive an antioxidant effect.

It is also possible to blend copper carboxylate as a compound formed with an inorganic boron compound. The presence of boron can contribute to the antioxidant effect and improve the extreme pressure performance of the additive.

According to the invention, the introduction of copper and optionally boron into micelles makes it possible to obtain a versatile additive with antioxidant and extreme pressure effects. Such multi-purpose additives are superior to mixtures of different additives because they eliminate the problem of incompatibility between additives as well as the problem of instability of the mixture.

The copper carboxylates used are obtained from linear or branched C7 to CIG aliphatic carboxylic acids such as tohebutanoic acid, ethylhexanoic acid or n-decanoic acid. α-olefins, or rather mixtures obtained by oxo synthesis from α-olefin fractions, can also be used advantageously. Such acid mixtures include C7 to CIO oxoacids branched in the alpha or beta position, or VERSATIC 10, available from Shelf.
10. Trademark of Shell Company). Versatic 1
The acids of No. 0 were obtained from branched c9 olefins by oxo reaction. These acids are especially tertiary acids (
1ertia Bacids), it consists of a trialkyl acetic acid structure.

Copper carboxylates are usually obtained by reaction of a carboxylic acid with cupric hydroxide or a mixture of cupric hydroxide and cupric carbonate in an organic solvent. Copper carboxylates can also be produced by replacing the sodium form of sodium carboxylate with a solution of an inorganic copper salt such as cupric chloride.

Copper carboxylates can be prepared as a solid containing about 12 to 17 parts of copper or as a solution.

When produced in solution form, the solvent is preferably the same as that used for carbonation. These copper carboxylates are dialyzed through a latex membrane.

Compounds of copper carboxylates and inorganic boron compounds are produced by reaction of copper carboxylate solutions with solutions of inorganic boron compounds such as ammonium borate, sodium tetraborate, sodium metaborate, or boric anhydride. A preferred boron compound is boric anhydride (810+).

A preferred solvent is a glycol ether such as propylene glycol methyl ether. The two solutions are mixed at a temperature near 100°C and the mixture is refluxed for at least 1 hour. After distilling off some of the solvent, a small amount of glycol, such as butyl glycol, is optionally added. The concentration of glycol is less than 5% by weight of the final mixture. The obtained carboxylic acid copper/boron compound is
It contains 8-12% by weight of copper and 0.8-2% by weight of boron, is a dark blue solution that quickly passes through latex dialysis membranes.

In the additives of the invention, copper carboxylates or copper carboxylate/boron compounds are used as a mixture of overbased additives with conventional detergents.

Such detergents include alkali metal or alkaline earth metal salts of naphthenic acids, sulfonic acids, phenols, salicylic acids, phosphonic acids or thiophosphonic acids which are soluble in hydrocarbon media.

The sulfonic acid used to produce the sulfonate may be petroleum-based or synthesized. Petroleum-based sulfonic acid is
Produced by sulfonation of oil obtained by distillation of petroleum. Although the structure of these sulfonic acids does not fit into any particular formula, their average molecular weight must be greater than or equal to 3fl[1].

Synthetic sulfonic acids are produced by alkylating an aromatic compound such as benzene, toluene, xylene or naphthalene as an olefin fraction, and then sulfonating the resulting alkylate. The structure of the alkyl chain attached to the ring is linear or branched depending on the olefin used for alkylation.

The number of carbon atoms per alkyl chain is 8 or more.

The preparation of an alkali metal or alkaline earth metal salt of a sulfonic acid involves combining the sulfonic acid with an alkali metal or alkaline earth metal compound (preferably an oxide or hydroxide) and optionally an alcohol in a hydrocarbon solvent. This is done by making contact with the object.

Alkali metal or alkaline earth metal salts of phenols are prepared from alkylphenols or sulfurized alkylphenols under similar conditions. The phenol ring may have one or two straight or branched alkyl chains having 8 or more carbon atoms. The most common compound is dodecylphenol.

The optional sulfurization of phenol can be carried out using -sulfur chloride (Ss
C1,) or elemental sulfur at a temperature in the range from 150°C to 200°C. The sulfurized product contains about 0.6 to 2 sulfur atoms per phenolic ring.

Alkyl salicylic acids are produced by alkylation of salicylic acid or carboxylation of alkylphenols under pressure. The alkyl chain contains at least 12 carbon atoms.

Phosphonates and thiophosphonates are added to polyisobutyne at P, 0. Or, after reacting with P or S, it is produced by neutralizing with an alkali metal or alkaline earth metal oxide or hydroxide. The molecular weight of polyisobutyne is 1
00 to 2000.

These detergents can be used in mixtures with dispersants soluble in the hydrocarbon medium. Examples of such dispersants include alkyl succinimides or molecular weights of 100 to 250.
There are 0 alkyl succinate esters.

The reaction mixture may also contain precursors instead of detergents. In this case, neutralization takes place in the reaction mixture immediately before carbonation.

The alkali metal or alkaline earth metal carbonate included in the additive composition of the invention is usually calcium carbonate or magnesium carbonate.

The multi-purpose additive of the present invention contains detergent mixtures, alkali metal or alkaline earth metal compounds, nitrogen-containing and/or
or by carbonation of a reaction mixture comprising an oxygenated promoter and optionally a hydrocarbon solvent, the detergent mixture containing at least one copper carboxylate derived from linear or branched C7 to CIO fatty acids; It is characterized by containing a compound of the carboxylate and an inorganic boron compound.

In addition to copper carboxylates, the detergent mixture also contains conventional detergents with overbased additives such as alkali metal or alkaline earth metal salts of naphthenic acids, sulfonic acids, phenols, salicylic acids, phosphonic acids or thiophosphonic acids. Contains.

The alkali metal or alkaline earth metal compound may be an oxide, hydroxide or alkoxide.

Preferred compounds are oxides and hydroxides, especially calcium oxide, calcium hydroxide, magnesium oxide or magnesium hydroxide.

These are added to the reaction mixture in excess of the stoichiometric amount relative to the detergent or its precursor. This stoichiometric excess can vary from 5:1 to 3o:1.

In the process of the invention, an oxygenated promoter, usually an aliphatic or aromatic alcohol, alkoxyalkanol, glycol or alkanolamine, is introduced into the reaction mixture before carbonation. C1 to C20 aliphatic alcohols or mixtures thereof are preferably used. Such aliphatic alcohols can also be used in mixtures with glycols, alkoxyalkanols or alkanolamines.

The molar ratio of oxygen-containing accelerator to detergent is usually between 1 and 1.
It is between 0.

The use of nitrogen-containing promoters is optional. The nitrogen-containing promoter is typically ammonia, ammonium salts, C2 to CIO
Selected among primary, secondary or tertiary amines and their carboxylic acids or borates, polyamines or alkanolamines.

Among the nitrogen-containing promoters, ammonia, ammonium carbonate, ammonium chloride, ethylenediamine, ethanolamine or jetanolamine are preferred.

The molar ratio of accelerator to detergent is usually between 1 and 10.
It is between.

The hydrocarbon solvent fully homogenizes the various reagents and reduces viscosity, which facilitates recovery of the solid carbonated residue. The solvent is 10 to 70% by weight of the reaction mixture.
corresponds to The solvent used is a C6 to C12 aliphatic or aromatic compound. Preferred solvents are aromatic solvents such as benzene, toluene, xylene, ethylbenzene and chlorinated aromatic compounds. The choice is determined by the properties of the additive to be recovered, the boiling point of the solvent, and the boiling point of the azeotrope that the solvent can form with the oxygenated promoter and water.

Handling of the overbased additive obtained according to the invention is facilitated by the addition of oil. This oil represents approximately 20-50% by weight of the resulting additive. The oil can be added to the reaction mixture before carbonation or after carbonation, ie just before solvent removal.

The diluting oil used here may be paraffinic, such as 100 or 150 neutral solvent;
Or naphthenic solvents such as 100-150 veil solvents.

The carbonation reaction is optionally carried out after adding water to the reaction mixture. Addition of water is particularly effective when the alkali metal or alkaline earth metal compound is an oxide. usually,
The amount of water added is such that the molar ratio of water/metal oxide is on the order of 0.5.

To carry out the method of the invention, a stirrer, a temperature control device,
The following components are sequentially charged into a reactor equipped with a carbon dioxide introduction device, a heating system, and a vacuum system: - 0 to 700 parts by weight of a hydrocarbon solvent - A stoichiometric excess of the detergent or its precursor an alkali metal or alkaline earth metal compound; the stoichiometric excess is from 5:1 to 10:1; an oxygen promoter; its molar ratio to the detergent is from 1 to 1;
optionally a nitrogen-containing promoter; its molar ratio to the detergent is between 1 and 10; optionally such that the water/metal oxide molar ratio is on the order of 0.5; an amount of water, optionally an amount of diluting oil corresponding to about 20 to 50% by weight of the additive recovered at the end of the operation, and 15 to 200 parts by weight of solid or liquid copper carboxylate or carboxylic acid. Copper/boron compound + 00 to 400 parts by weight of a conventional detergent or detergent precursor.

If a detergent precursor is used, it is preferred to sequentially add the precursor, excess alkali metal or alkaline earth metal compound, and oxygen-containing promoter. The precursor is then neutralized prior to adding other mixture components for carbonation.

The carbonation of the stoichiometric excess of the alkali metal or alkaline earth metal compound is carried out at a temperature between room temperature and the reflux temperature of the mixture. The molar ratio of the introduced CO2 to the stoichiometric excess of the alkali metal or alkaline earth metal compound is between 0.6 and 1.2. The mixture is stabilized by heating under reduced pressure or under a stream of nitrogen to remove optionally low-boiling oxygen-containing promoters and added water as well as water produced by carbonation. Solid residues are removed by centrifugation and/or filtration through diatomaceous earth.

If diluent oil is not added before carbonation, the hydrocarbon solvent and heavy alcohol are removed by first adding diluent oil and then heating under reduced pressure at a temperature in the range of 10G to 200°C depending on the case. .

The above filtration operation may be performed before solvent recovery.

100% copper (and possibly boron) uptake
Close to.

The overbased additives of this invention are clear, stable liquids. Its color is generally blue. Phenolates and salicylates are much darker in color than sulfonates.

Neither copper nor boron present in the additive of the invention is dialyzed through the latex membrane, demonstrating that these compounds are incorporated into the micelles.

The copper content of the additive of the invention is 102 to 5% by weight, preferably 0.8 to 3% by weight, and the boron content is 0 to 1% by weight, preferably 0.2 to 0.8% by weight. be.

This additive is characterized by its copper and boron content, its ■KOH
Total alkaline number expressed in /g (abbreviated as TBN; ^STM
D-2896 standard) and its stability when diluted to 70 mg KOR/g of TBN in a base oil mixture.

The additives can be incorporated into natural or synthetic lubricating oils at concentrations of 0.5 to 40% by weight, preferably 1 to 10% by weight.

This amount translates to concentrations in the final lubricating oil formulation of 0.004 to 1.2% by weight copper and 0 to 0.3% boron.
This corresponds to 2% by weight.

The lubricating oil compositions thus obtained may contain polymers that improve the viscosity index as well as additives with anti-wear, dispersing, cleaning, anti-oxidation or friction-modifying effects.

The invention is illustrated by the following examples, but the invention is not limited thereto.

Percentages are by weight unless otherwise specified.

Example A: Cecxnoic acid containing 96% copper carboxylate active ingredient
! cid) Ckg (CDF Chimie) 25
were brought into contact with 316 ml of 0.5N sodium hydroxide solution in a reactor equipped with a stirring system and a heating device. 90℃
After heating for 10 minutes at
3.8g of second steel chloride (C11CJI・2HIO)
Added over 0 minutes. The resulting blue precipitate was collected by filtration, washed and dried. 27.9 g of finely divided solid containing 16.5% copper was recovered.

Example B: 72 g of copper xylene carboxylate, 511 with 2-ditylhexanoic acid and Berketic 10 acid (Shell Chimie):
50 g of a mixture by weight, as well as basic copper carbonate (
CoC0+・Cu (OH)! ) was charged into a reactor equipped with a stirring system, a temperature control device and a Dean-Stark device. Azeotropically distilled for 1 hour and 10 minutes to obtain 2 ml of H.
of water was collected. After filtration or centrifugation, 214 g of a neutral copper salt solution in xylene (copper content 1103%) were obtained.

Example C: Carboxylic Acid Copper/Boron Compound 770 g of the carboxylate solution obtained in Example B were used. This solution was kept at 110°C. 32g of boric anhydride (
Bt O+ ) was dissolved in 288 g of propylene glycol methyl ether (boiling point: 120 °C) at 100 °C. This boron solution was added to the carboxylate solution over a period of 20 minutes. After refluxing for 1 hour, the reaction mixture was observed to become completely clear. All of the ether and some of the solvent were then distilled off to obtain a copper content in the order of 0.2%.

Then 10 g of butyl glycol was added to completely stabilize the mixture.

The resulting product contained 1000% copper and 1.38% boron.

Example 1: (Comparative Example) The following components were sequentially introduced into a 1-liter reactor equipped with a temperature control device, a condenser, a stirring system, and a gas introduction device.

Toluene 110ml, alkylarylsulfonic acid with linear alkyl chain (molecular weight 4101 active ingredient 96%)
32.95 g, 100 neutral solvent (diluent oil) 42 g 1 96% pure slaked lime 2131 g, and methanol 12 ml. Sulfonic acid was neutralized with slaked lime (
(If necessary, the reaction mixture can be heated for 10 minutes at 60°C), and then the temperature of the mixture maintained at 42°C is
3.5 g of carbon dioxide were introduced. After carbonation, methanol and water produced by the reaction were removed by heating the mixture under reduced pressure. 2% by weight of DixtomeesClsrc
The mixture was clarified by filtration using el DiC3SCECA SA).

Contains 13% calcium after solvent removal +03g
of product was obtained. Its total alkali value is 313■KO
It was H/g.

The product was brown clear and stable upon dilution into mineral or synthetic oils. No turbidity or precipitation was observed even after storage at 60°C for several weeks.

Example 2; (Comparative example) The procedure was the same as in Example 1, except that 10 g of alkylarylsulfonic acid having a branched alkyl chain (molecular weight 5201, active ingredient 70%) and 210 g of Co were introduced. The amount of diluent oil was 22.5 g. The product exists as a brown liquid and its total alkalinity number is 37! ImgKO
It was tl/g. This product is stable with respect to dilution into lubricating oils and its viscosity at 20°C is 1825
There were 0m21 customers.

Example 3 The procedure was similar to Example 1, except that the solution prepared in Example C prior to carbonation with 12 g of carbon dioxide
was introduced into the reaction mixture.

112 g of overbased sulfonate containing 6.96% copper and Q, 117% boron was recovered. Its total alkaline value was 314 ■KOH/g, and its viscosity at 20°C was 3500 mF>.3. The product was blue in color and completely stable upon dilution into oil.

Example 4 The procedure was similar to Example 1, except that 15 g of the solution prepared in Example C were introduced before carbonation with 12 g of C02. 111 g of overbased sulfonate containing 1.41% copper and 0.15% boron were recovered.

Its total alkaline value is 109 ■ K Off / g, part 2
The viscosity at 0° C. was 495,011 PI·$. Its stability with respect to dilution with oil was remarkable.

Example 5 The procedure was similar to Example 1, except that 20 g of the solution prepared in Example C were added before the carbonation of Ilg with CO2. 115.5 g of overbased sulfonate containing 1.88% copper and 0.224% boron were recovered. Its total alkali value is 297 ■KOH/g, and its viscosity at 2Q°C is 11650111P!・It was S. It was completely stable upon dilution into mineral or synthetic oils.

In contrast to the solution obtained in Example C, none of the products obtained in Examples 3, 4 and 5 passed through the dialysis membrane. This provides indirect evidence of the incorporation of copper and boron within the dispersion of calcium carbonate colloids that are the main component of these products.

The intoxication procedure was similar to Example 2, except that 8.3 g of CO□
4 g of the copper carboxylate described in Example A were added to the reaction mixture before the carbonation using. 75 g of overbased sulfonate containing 0.85% copper was recovered.

Its stability on dilution in oil was moderate. The color is dark green, and the viscosity at 20°C is 250.
000 mPa・s, total alkaline value is 334 mgKO
It was H/g.

The loading procedure was similar to Example 2, except that 8.3 g of CO2
1.5 of the copper carboxylate described in Example A before carbonation using
g was added to the reaction mixture.

When the same operation as in Example 2 was performed, the total alkali number was 32.
73 g of green-brown final product was recovered at 3 mg OH/g. The viscosity at 20° C. was 8850 mPa·rich, and the copper content was 0.33%. The product was stable upon dilution into oil.

In contrast to the product of Example A, neither the solvent-diluted products of Examples 6 nor 7 penetrated the dialysis membrane.

Example 8 The procedure was as in Example 1, except that 20 g of the cupric solution prepared in Example B were added before carbonation with 12 g of CO□. When the same operation as in Example 1 was performed, 1. %
of copper and has a total alkaline value of 321 mg KO) I/H
113 g of overbased sulfonate were recovered. The color was blue-green and the stability with respect to dilution in oil was remarkable.

Example 9: (Comparative example) 250 equipped with a condenser, temperature control device and gas introduction device
7 in a milliliter reactor at a temperature of 20 to 10°C.
7.8 g of dodecylphenol and 20 g of sulfur chloride were introduced. Flushing with nitrogen and stirring, the mixture was heated at 150° C. for 1 hour, at 180° C. for 1 hour, and finally at 200° C. for 1 hour. Sulfurized dodecylphenol was recovered with chlorine and sulfur contents of 2200 ppm and 0.4%, respectively.

Another 2 with stirring system, temperature control device and gas introduction device
In a 50 ml reactor, 43 g of dodecylphenol sulfide, 10 g of 100 neutral solvent (diluent oil), 90Q11 xylene, Il, 8 g of calcium oxide, 66 ml of methanol and 2 g of calcium nitrate (Ca(NO+) t.40 .0) were introduced sequentially. The mixture was refluxed for 45 minutes before removing the water produced by neutralization. After adding 65 ml of methanol to this mixture, the stoichiometric excess of lime was carbonated with carbon dioxide at 50°C. After carbonation, residual water and methanol were removed by heating under reduced pressure, and the solid residue was collected by filtration.

After evaporating off the solvent, a green-brown overbased sulfurized dodecyl phenolate stable in oil was obtained.

Its total alkali value was 245 mgKOH/g.

The Houtan procedure was similar to Example 9, except that the cupric solution prepared in Example B was introduced into the reaction mixture immediately after removing the water produced by the neutralization of the sulfurized dodecylphenol. The remaining procedure was the same as Example 9.

Contains 1.1% copper and has a total alkali value of 251K
91 g of n/g overbased calcium sulfide dodecyl phenolate were recovered.

The product was dark green in color and stable upon dilution into base oil.

Example 11: (Comparative Example) The procedure was similar to Example 1, but with 78 g of (C1+, Cm
-alkyl) salicylic acid, 9.49 g slaked lime, 37 m
1 of methanol and 25 g of diluent oil were introduced into the reactor.

After neutralization and carbonation at 42° C. with 1.9 g of CO2, 7.5 g of lime was added and carbonation was performed with 2.5 g of CO□. A stable additive was recovered in a dark brown oil. Its calcium content is 7.6% and its total alkaline value is 2.
It was 05■KOR/g.

MI2 The procedure was similar to Example 11, except that the cupric solution tag from Example B was introduced into the reaction mixture after neutralization of the salicylic acid. The remaining procedure was the same as Example 11.

120 g of overbased calcium alkyl salicylate containing 0.85% copper was recovered. Its total alkalinity number was 201 mg KOH/g and was stable upon dilution into base oil.

Example 13 The procedure was similar to Example 2, except that 4 g of copper carboxylate from Example B were added to the reaction mixture after carbonation. A slightly cloudy, blue mixture was obtained. Its total alkaline value is 10
It was 0)1/g.

Example I4 The performance of the additive was evaluated by oxidation test.

10 g lubricant samples containing various amounts of additives were heated at 165° C. for 64 hours. 40pp of iron in acetylacetonate form
The oxidation was catalyzed by m. At the end of the experiment, the temperature was returned to 40°C and the viscosity at 40°C before and after oxidation was compared. The increase in viscosity (ΔV) was expressed as a percentage of the initial viscosity. The lower this percentage, the more effective the additive is.

Tables 1 and 2 summarize the results of viscosity measurements for two lubricating oil formulations A and B.

A = mineral oil containing 0.6% sulfur, 1% zinc primary dithiophosphate; B = 106% sulfur, 1% zinc primary dithiophosphate;
Mineral oil containing 3.3% dispersant From these two tables it can be seen that the overbased sulfonate exhibits a pro-oxidizing effect. In fact, the overbased sulfonate salts produced in Comparative Examples 1 and 2 lead to coagulation, making viscosity measurement impossible. The overbased phenolate (Comparative Example 9) also increases the viscosity compared to the sample without the additive, but its pro-oxidant effect is low.

Table 1 shows that the addition of the additives of the present invention can reduce and even suppress the oxidizing effect of overbased additives (Examples 5.7 and 1G). Additive 5, which also contains boron, is more effective than additive 7, which only contains copper.

The additives of the present invention can be used in mixtures with conventional overbased additives, provided the copper content is 160 ppm or more. In fact, coagulation cannot be prevented unless copper is present at 40 ppm.

Table 1 Lubricating oil formulation A Additive Additive Copper Boron ΔV (40°C)
Example Weight % ppm ppm %1
(Comparison) 0.85 - Solid 5
0.85 160 20 137
2 (Comparison') 4.23 - Solid 2 + 6 3.5 + 0.5 40 - Solid 2 + 6 2.5 + 2 166
2597 5 166 5
099 (comparison) 1.5- 25710
1.45 166 - 35Table 2 is
It is shown that the pro-oxidant effect of the overbased additive is reduced by the addition of the copper-containing additive (Example 7), whereas the conventional amine antioxidant is unable to prevent coagulation of the sample.

For the same copper content around 160 ppm, it is better to use a single additive (Example 7) than a mixture of a traditional overbased sulfonate and a copper-containing overbased additive (Example 2+6.1+
3.1+5).

Previous mixtures of overbased sulfonates and copper carboxylates have yielded unsatisfactory results.

Table 2 Lubricating oil formulation B 2 (comparison) 2 (comparison) 2+6 1 (comparison) 1+3 1+5 2+13 4.23 4.23 100, 2% L57” solid solid 2, 5+2 4.8 3,09+1.7 3,96+0.88 1.7+2.6 66 66 +63 +65 6G 0 0 100 98 solid 010 000 450 Ne 57 Amine type antioxidant

Claims (13)

[Claims] (1) An overbased additive for lubricating oils comprising carbonates of alkali metals or alkaline earth metals dispersed in diluent oil by the action of a detergent mixture; C_1_0 An additive characterized by containing at least one type of copper carboxylate obtained from aliphatic carboxylic acids. (2) The additive according to claim 1, wherein the copper carboxylate is blended in the form of a compound formed with an inorganic boron compound. (3) In the additive according to claim 1 or claim 2, 0
．． An additive characterized in that it contains 2 to 5% by weight, preferably 0.8 to 3% by weight of copper, and 0 to 1% by weight, preferably 0.2 to 0.8% by weight of boron. (4) The additive according to claim 2, wherein the inorganic boron compound is ammonium borate, sodium tetraborate, sodium metaborate, or preferably boric anhydride. (5) The additive according to any one of claims 1 to 4, wherein the carboxylic acid is n-heptanoic acid, ethylhexanoic acid, or n-decanoic acid. (6) The additive according to any one of claims 1 to 4, wherein the carboxylic acid is an α-olefin or an α-olefin.
- An additive characterized in that it is a mixture obtained from an olefin fraction by oxo synthesis. (7) The additive according to claim 6, wherein the acid obtained by the oxo synthesis is VERSATIC 10 (trademark of Shell) sold by Shell. (8) The additive according to any one of claims 1 to 7, wherein the detergent mixture is an alkali metal or alkaline earth metal salt of naphthenic acid, sulfonic acid, phenol, salicylic acid, phosphonic acid, or thiophosphonic acid. An additive characterized by containing. (9) The additive according to any one of claims 1 to 8, wherein the alkali metal or alkaline earth metal carbonate is calcium carbonate or magnesium carbonate. (10) By carbonation of a reaction mixture comprising a detergent mixture, an alkali metal or alkaline earth metal compound, a nitrogen-containing and/or oxygen-containing accelerator, and optionally a hydrocarbon solvent in a diluent oil. 9. The method for producing an overbased additive according to any one of Item 9, wherein the detergent mixture comprises at least one copper carboxylate obtained from linear or branched C_7 to C_1_0 fatty acids or said carboxylate salt. A method characterized in that it comprises a compound with an inorganic boron compound. (11) The method according to claim 10, wherein the alkali metal or alkaline earth metal compound is an oxide, hydroxide or alkoxide, preferably calcium or magnesium oxide, or calcium or magnesium hydroxide. How to do it. (12) A lubricant composition comprising 0.5 to 40% by weight, preferably 1 to 10% by weight of the additive according to any one of claims 1 to 9. (13) A composition according to claim 1, characterized in that it contains polymers that improve the viscosity index together with additives having anti-wear, dispersion, cleaning, anti-oxidation or friction-modifying effects.