CA2044035A1 - Phosphorus-containing alcaline or alcaline-earth phenate with excess base, and lubricant compositions holding said phenate - Google Patents

Abstract

1 Overbased alkaline or alkaline earth phenate obtained by carbonation of a mixture containing a phenolic compound, an organic phosphorus derivative, an alkali or alkaline earth metal derivative, a nitrogenous and / or oxygenated promoter, a hydrocarbon solvent and optionally a diluting oil and water. The incorporation of phosphorus during carbonation makes it possible to avoid negative interactions between overbased phenates and organic phosphorus derivatives.

Description

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SOCIETE NATIONALE ELF AQUITAINE

ALKALINE OR ALKALINE-BASE PHENATE BASE CONTAINING
PHOSPHORUS AND LUBRICATING COMPOSITIONS CONTAINING SAID
PHENATE
This invention relates to alkaline phenates or alkaline earth overbased, high alkaline value containing an organic derivative of phosphorus and their use in lubricant formulations.
Overbased phenates are salts of alkali metals or alkaline earth of phenols overbased by carbonation with carbon dioxide. The term overbased is used to designate the excess of alkali or alkaline earth metal by ratio ~ the stoichiometric amount needed to neutralize phenol.
The structure of overbased phenates is that of a dispersion colloidal whose micelles contain the metal carbonate alkaline or alkaline earth formed during carbonation.
The micelles are stabilized by alkaline phenates or alkaline earth which have a detergent effect.
These overbased phenates are particularly useful in lubricants used in internal combustion engines from "petrol" or "diesel" type, whether engines terrestrial or marine.
Thanks to their detergent and dispersing effect they prevent formation of lacquers and varnishes on the pistons, and keep soot from combustion dispersed fuel incomplete.
Another important function of these additives is the - -neutralization of the acid compounds resulting from the oxidation of oil or the combustion of sulfur products brought in by the fuel. This function is particularly appreciated when using sulfur-rich fuels like for example heavy fuels used in engines sailors.

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Overbased phenates further improve resistance to the oxidation of the oils in which they are incorporated. this property is more particularly marked in case use of sulfurized phenols. This function is particularly appreciated for lubricant formulations subject to severe thermal stresses, such as example in highly supercharged diesel engines. The sulfurized overbased phenates are in practice more used than their non-sulfurized counterparts.
Overbased phenates are characterized by their value alkaline (VA) expressed in mg of KOH per gram of product.
It is determined by titration ~ using a strong acid according to ASTM D-2 ~ 96. A reserve of alkalinity significant results in a high VA.
In the prior art, there are essentially two types of processes for the production of overbased phenates.
European patent applications 0300486 and 0259974 describe a high temperature process, around 160 ~ C and ~ a pressure higher than atmospheric pressure. This procedure does not allow to obtain overbased phenates of alkaline value ~ raised -provided that an alkysulfonate is associated with the alkylphenate during carbonation.
French patent 2,305,494 relates to a low process temperature, around 50C. In the absence of an alkyl sulfonate, the the alkaline value of the phenates alone never exceeds 240. In in addition, these products have the disadvantage of being unstable over time and have a high viscosity.
These processes therefore do not allow the synthesis of phenates has high alkaline value.
It is also known to use in lubricants mixtures of overbased phenates and phosphorous additives or phosphosoufr ~ s. These bring properties antiwear and antioxidant. The most commonly used are metal salts of dithiophosphoric acid and more especially the zinc salt of the acid dialkyldithiophosphoric.

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However, it turns out that negative interactions can exist between overbased phenates and organic derivatives phosphorus, and in particular the zinc salt of the acid dialkyldithiophosphoric. The competition, during adsorption on metal surfaces to be lubricated, between overbased phenates and zinc salts or reactions between these two additives in the volume of the lubricant can cause a significant decrease in properties antioxidant and anti-wear. We have now found that carbonating the phenates in the presence of a organic compound of phosphorus, there is incorporation of phosphorus in the micelle, which also contains the alkali or alkaline earth metal carbonate. So the negative interactions between overbased phenates and organic phosphorus derivatives are avoided. In a way surprisingly, the overbased phenates carbonated in the presence of organic phosphorus derivatives have value alkaline superior to that of the overbased phenates of art prior. At the same time their stability is better and their viscosity low enough so that no handling problem.
To our knowledge, the carbonation of an alkaline phenate or alkaline earth in the presence of an organic compound of phosphorus is not described in the prior art. Requirement British Patent No. 2197336 relates to the addition of catalytic amounts of a zinc dialkyldithiophosphate oil-soluble, to an alkaline phenate, but it is a use as a sulfurization catalyst, in a two-step process, including sulfurization of phenol then its carbonation. At the sulfurization temperature, between 145 and 165-C, the dialkyldithiophosphate breaks down into mercaptan and olefin, and in the carbonation stage the mixture no longer contains organic phosphorus.
The invention therefore relates to an alkaline phenate or alkaline earth overbased, obtained by carbonation of a mixture containing a phenolic compound, a derivative of a alkali or alkaline earth metal, chosen from oxides, hydroxides or alcoholates, a nitrogenous and / or oxygenated promoter, :. -. . . :. ... . --:. :. . .
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2 ~ 4 ~ 35 a hydrocarbon solvent and optionally a diluent oil and water characterized in that the mixture contains phosphorus in the form of an organic derivative.
The overbased phenates obtained according to the invention are present in the form of a clear and stable colloidal dispersion.
Their alkaline value (VA) is greater than or equal to 250. The prior art methods did not allow obtaining phenates at VA greater than 240. Values greater than $
been obtained only with mixtures of phenates and sulfonates.
The presence of the organic phosphorus derivative gives the overbased phenates according to the invention of the properties enhanced antioxidants as well as antiwear properties.
Among the organic phosphorus derivatives, preferably non-metallic compounds. These derivatives non-metallic organic phosphorus are selected from phosphites, phosphoramides, derivatives of acids phosphoric, thiophosphoric, dithiophosphoric, trithiophosphoriques, tetrathiophosphoriques and their salts organic.
More particularly, the phosphosulfur derivatives are used like thiophosphoric or dithiophosphoric acids and their organic salts and preferably the deriv ~ s of acids dithiophosphoriques and their organic salts.
Among the dithiophosphoric acid derivatives used in general dihydrocarbyldithio-phosphoric acids, general formula RO
P ~ (I) R'O '''' SH
where R and R 'identical or different represent chains linear or branched C1 to C20 alkyls, cycles aliphatic or aromatic.
Among these derivatives we can mention the acid diethyldithiophosphoric, diisopropyldi- acid thiophosphoric, dicyclohexyldithiophosphhoric acid or Dicrésyldithiophophorique acid.
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2 ~ 0 ~ 5 It is particularly advantageous to use the compounds of general formula (I) insoluble in oils. These compounds have antioxidant and antiwear properties surfactant effect. So they participate as co-surfactants stabilization of the micelles.
The overbased phenates obtained according to the invention contain 0.5% to 10 ~ weight and preferably 1 to 5% weight of phosphorus.
To obtain this final phosphorus concentration, the carbonate mixture must contain at least 3% phosphorus in the form of an organic derivative.
Dihydrocarbyldithiophosphoric acids of formula general (I) can be prepared by the action of phosphorus pentasulfide on an alcohol or phenol of formula yenérale R-OH or a mixture of alcohols or phenols of formula R-OH and R'-OH.
The molar ratio of phosphorus pentasulfide to alcohol or phenol must be at least 1 to 4. The reaction can be performed at a temperature between 40 and 200C, this ci depending on the type of alcohol or ph ~ nol chosen.
Acid preparation methods dial ~ yldithiophosphoriques are described in the patents American 3089850, 3101096, 3293181 and 3489682.
The phenolic compounds are generally alkylphenols, comprising one or more linear alkyl groups or branched in Cl to C30. To ensure solubility to phenates corresponding alkali or alkaline earth in oil dilution, the total number of carbons of the group (s) alkyls must be equal to or greater than eight.
Alkylphenols can be prepared by the reaction of a olefin or a mixture of olefins on phenol, in the presence of a catalyst at a temperature between 60 and 200-C.
The alkylphenols used can optionally be sulfurized by the action of elementary sulfur at temperatures ranging from 150 to 200-C., or by the action of a sulfur halide such as mono or sulfur dichloride.
The sulfuris product ~ contains 1 to 1.5 sulfur atoms per phenolic nucleus, but its structure is not known with precision.

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Among the alkali or alkaline earth metal derivatives are uses oxides, hydroxides or alcoholates. The rivals prefer ~ s so ~ t oxides and hydroxides.
These are added to the reaction medium in excess stoichiometric with respect to the phenolic compound. Excess stochiometric can vary between 5: 1 - and 30: 1.
The oxygenated promoter is generally an aliphatic alcohol or aromatic, an alkoxyalkanol, a glycol or even a alkanolamine. We preferably use alcohols aliphatic in C1 to C20 or mixtures thereof. Alcohols aliphatics can be used in admixture with glycols, alkoxyalkanols or alkanolamines.
The molar ratio of the oxygen ~ promoter to the phenolic compound e ~ t generally between 1 to 30.
The use of a nitrogenous promoter is optional. The nitrogen promoter is generally chosen from ammonia, ammonium salts, primary, secondary or tertiary in C2 to C10 and their salts, polyamines or alkanolamines as well as nitro mineral compounds.
Among the nitrogenous promoters, ammonia, carbonate and ammonium chloride, ethylenediamine, ethanolamine or diethanolamine, as well as nitrate of calcium.
The molar ratio of the nitrogen promoter to the phenolic compound is generally between 0.05 and 30.
Hydrocarbon solvent allows perfect homogenization different reagents as well as lowering the viscosity, which will later facilitate recovery solid carbonation residues. The solvent represents generally 10 ~ 70% by weight of the reaction mixture. The solvents used are aliphatic compounds or aromatics in C6 to C12. The preferred solvents are aromatic solvents, such as benzene, toluene, xylene, ethylbenzene and chlorinated aromatics. Their choice is dictated by the characteristics of the additive collected, by their boiling point and by the boiling point of azeotropes that they can form with oxygen compounds ~ s and water.

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The manipulation of overbased phenates is facilitated by the addition of a diluting oil. The oil represents approximately 20 to 50% by weight of the additive obtained. This can be added to the reaction medium before carbonation or still after this, that is to say just before elimination solvents. The diluent oils used are of a nature paraffinic, type 100 or 150 Neutral Solvent or of a kind mostly naphthenic such as 100-150 Pale Solvent.
The carbonation reaction can be carried out after optional addition of water to the reaction medium. The bill of water is particularly beneficial when the derivative of alkali or alkaline earth metal is an oxide. Usually the amount of water added is such that the molar ratio water / metal oxide is around 5.
In more detail, the process for obtaining phenates consists at :
a, neutralize the phenolic compound, generally a alkylphenol or a sulfurized alkylphenol whose total number of carbon of the alkyl groups is ~ gal or greater than eight, by an alkali or alkaline earth metal derivative, in presence of a nitrogenous and / or oxygenated promoter and optionally a diluent oil, a hydrocarbon solvent and water, b, add an organic phosphorus derivative, preferably a non-metallic derivative and better a phosphosulfur derivative, then carbonate the mixture with carbon dioxide gas for a time sufficient to consume in part or in totality of excess of alkali or alkaline earth metal, c, remove solid residues and solvents.
A preferred implementation of the method consists in successively introduce into a reactor equipped with a agitator, temperature control, heating and evacuation:
- 0 to 700 parts by weight of ~ n hydrocarbon solvent, - 100 ~ 400 parts by weight of an alkylphenol or a pre-sulfurized alkylphenol, - an excess of alkali or alkaline earth metal derivative stoichiometric ~ e relative to phenol.
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This stoichiometric excess is between 5: 1 and 30: 1, - an oxygenated promoter whose molar ratio to phenol is between l and 30, - optionally a nitrogenous promoter whose molar ratio phenol is between 0.05 and 30, - possibly a quantity of water such as the ratio molar water / alkali or alkaline earth metal oxide either around 0.5, - a diluting oil in quantity such as this represents 20 to 50 ~ by weight of the additive recovered at the end operations.
The phenolic compound neutralization reaction is performed at a temperature between about 30 and 120 ~ C
and preferably at a temperature between 50 and 100-C, for a period of approximately 0.5 to 4 hours.
After this neutralization, the reaction medium is added to the reaction medium.
organic phosphorus derivative. Phosphorus concentration of the reaction medium must be greater than or equal to 3%.
we then proceed to carbonate the excess alkali or alkaline earth metal stoichiometric at a temperature between room temperature and reflux temperature of the mixture and more particularly at a temperature between room temperature and 50-C and preferably at a temperature between 30-C and 45C.
The molar ratio of carbon dioxide introduced to excess alkali or alkaline earth metal stoechiom is between 0.6 and 1.2. The mixture is eventually stabilized by heating under vacuum or under a stream of nitrogen, so as to eliminate low point oxygenated promoters boiling water and the added water, as well as the water produced by the carbonation reaction. Solid residues are generally, by centrifugation and / or filtration at using diatomaceous earth.
If the diluent oil was not added before carbonation, it is then added before removing the solvent hydrocarbon and possibly alcohol. These last are removed by vacuum heating at temperatures of in the range of 10 to 200-C.

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, -The phenates on ~ asés, obtained according to the invention are of brown coloring and stable over time. Their viscosity is as they can be handled ~ room temperature. They contain 0.5 to 10% by weight and preferably l to 5% of phosphorus.
These overbased phenates are fully compatible with hydrocarbons. They are incorporated into lubricating oils of natural or synthetic origin at a concentration between about 0.5 and 40% by weight and preferably between 1 and 30% by weight.
The lubricant compositions thus obtained can contain other additives, with antiwear effect, dispersant, antioxidant and polymers improving the index of viscosity.
The examples below illustrate the invention without, however, limit it.
In the examples the basicity of the overbased phenates is characterized by their alkaline value (VA) expressed in mg KOH / g of product. The VA is determined by titration using of a strong acid according to standard ASTM D-2896.
Unless otherwise indicated, all percentages are in weight.
EXAMPLE A
Preparation of dimethyldithiophosphoric acid In a 1 1 reactor fitted with a stirring system, a temperature, refrigerant and system regulation introduction of reagents, coupl ~ ~ a system of neutralization of acid gases, we suspend in 600ml of car ~ one tetrachloride, 133.45g of pentasulfide phosphorus. The suspension is cooled to 3C and 153.6 g of methanol are added in 0.5 h, maintaining the temperature below 5-C. we then add in lh and in portions, an excess of about 30% of m ~ thanol over has the stoichiometry of the reaction. The mixture is then carries ~ reflux until it becomes perfectly clear.
The solution is cooled and filtered on a Millipore filter 0.22 ~ m, then the solvent evaporated.

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EXEMPLB 1 (comparative) In a 250ml reactor fitted with a condenser, a temperature regulation and a bubbling device gas, we successively introduce:
- 90ml of xyl ~ ne - 49.5 g of the product of Example F
- 20, lg of slaked lime ~ 96% purity - 50ml of methanol - 2.55g of ammonia ~ 20%
The mixture is brought to reflux for 0.75 h before elimination water produced by the neutralization of dodecylphenol sulfurized. 50 ml of methanol are added before proceeding to the carbonation by excess carbon dioxide stoichiometric lime, at a temperature of 40-C. After carbonation is eliminated by heating under partial vacuum residual water and methanol before recovering the solid residues by filtration. 30g of oil are added diluent ~ 00 Neutral before removing the solvent.
We recover an overbased sulfurized phenate of brown color, VA = 240 and a viscosity of 48 Pa.s.
BXEMPLE 2 (comparative) In an assembly identical to that of Example 2, we successively introduced:
- 90ml of xylene - 43g of the product from Example F
- 12g of quicklime - 66ml of methanol - 2g of calcium nitrate We then proceed as in Example 2 and collect a overbased sulfurized phenate of VA = 245, with a viscosity of 115 Not.

We operate as in Example 1 ~ the difference we add 16g of the product of Example B just before the operation of carbonation. The procedure is the same as in Example 1 except that the residues are removed by centrifugation.
The product collected is dark brown and its viscosity is 30 Pa.s. Its VA = 250 and its calcium and phosphorus contents are 8.6% and 2.2% respectively.
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--:. -, ~ '' `"`; 2 ~ Q35 12 This overbased sulfurized phenate containing a compound phosphosulfur is remarkably stable when diluted in oil after several months.
EXAMPLE ~ ~
We operate as in Example 3 except that we add 15g of ammonium diethyldithiophosphate with g5% purity of JANSSEN CHEMICA in place of the product of Example B.
an overbased sulfurized phenate of VA = 255 is recovered, the calcium and phosphorus contents are 8.7% and 2.1%
respectively. The additive has good stability in dilution in oil after several months.

we operate as in example 2 with the difference that we add 13g of the product of example B.
The overbased sulfurized phenate collected at a VA = 250 and its viscosity is 70 Pa.s. Calcium and phosphorus contents of the additive are 8.1% and 2.1% respectively. The product has good stability when diluted in oil after several months.

we operate as in example 3 with the difference that introduces 25g of lime ~ tint into the initial mixture.
We recover an overbased sulfurized ph ~ nate of VA = 280, of which the calcium and phosphorus contents are 9.7% and 2.1%
respectively. The additive has a viscosity of 200 Pa.s and its stability when diluted in oil is good.

we operate as in example 6 ~ the difference we introduced 48.5 g of the product of Example F into the mixture initial.
An overbased sulfurized phenate of VA = 305 is recovered, the calcium and phosphorus contents are 10.6% and 2%
respectively. The additive has a viscosity of 250 Pa.s and its stability when diluted in oil is good.

The performance of new overbased phenates containing a organic compounds of phosphorus are tested on tests in the laboratory for reliability, wear, detergency and oxidation.

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The test matrices correspond to lubricants for marine engines on the one hand and for land engines on the other go.
The products are firstly tested in simple dilution.
Stability test (simple dilution) The products tested are diluted ~ VA = 70 and at VA = 20 in a mixture of lubricating bases 600 Neutral Solvent / Bright Solvent stock (20/80), the samples are placed in a oven at 60 ~ C and their stability is observed after one month.
Table I shows that the new overbased phenates containing a phosphorus compound are perfectly stable diluted while this is not the case for phenates classic overbased prepared by a "low" process temperature".
TA ~ LEAU I
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product of the example stability in dilution VA = 70 VA = 20 ... ..
1 (comparative) depot deposit 2 (comparison) deposit deposit

3) limpid limpid

4) crystal clear crystal clear

5) crystal clear crystal clear

6) crystal clear crystal clear

7) crystal clear crystal clear Wear test ~ or ~ motor ~ _ marine) The products are then tested in a formulation lubricant for marine engines (cylinder oil). Basicity oil is 70mg KOH / g of which only 10mg KOH / g contribution ~ s by overbased sulfurized phenate containing a compos ~ phosphor ~.
FALEX trial The test is carried out under the following conditions:
- running-in: 5 minutes 80US 300 lbs ~ normal load) - 3 hours test sou ~ gO0 lbs (normal load) These conditions are close to extreme pressure.

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~ 20 ~ 403 ~ 14 Table II shows a significant reduction in wear with the sulfuris phenate ~ overbased containing a compound ~
phosphosulfur.
TABLE II

Product of the example FALEX results wear ~ teeth) weight loss 1 (comparative) 32 29 . .
Wear test (lubricant for land diesel engine) Lubricant formulations for land diesel engine contain 2.8% overbased phenate and 1.5% phosphorus. This phosphorus is brought on the one hand by the compound ~
phosphosulfur, on the other hand by the dialkyldithiophosphate of zinc (DTPZ) FALEX trial The test is carried out under the following conditions:
- running in = 5 minutes under 200 lbs (normal load) - 3 hours of test under 540 lbs (normal load) Table III shows that there is a significant reduction of wear.
TA ~ LEAU III

Product of the FALEX results example wear (teeth) weight loss (mg) 1 (comparative) 32 38 6 14 7.4 ~ ,.

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Claims (16)

1 - Overbased alkaline or alkaline earth phenate, obtained by carbonation of a mixture containing a compound phenolic, an alkali metal derivative or alkaline earth, chosen from oxides, hydroxides or alcoholates, a nitrogenous and / or oxygenated promoter, a solvent hydrocarbon and possibly a diluent oil and water characterized in that the mixture contains phosphorus in the form of an organic derivative. 2 - Phenate according to claim 1 characterized in that the mixture contains at least 3% phosphorus in the form organic derivative. 3 - Phenate according to claim 1 or 2 characterized in that that the organic phosphorus derivative is a non-compound metallic, such as phosphites, phosphoramides and derived from phosphoric acids. 4 - Phenate according to claim 3 characterized in that the non-metallic drift of the posphore is a derivative phosphosulfurized like thiophosphoric acid, dithiophosphoric, trithiophosphoric or tetrathiophosphorique and their organic salts. 5 - Phenate according to claim 4 characterized in that the derivative of dithiophosphoric acid is an acid dihydrocarbyldithiophosphorique of general formula (I) where R and R 'identical or different represent linear or branched alkyl chains in C1 to C20, the aliphatic or aromatic cycles. 6 - Phenate according to claim 5 characterized in that dihydrocarbyldithiophosphoric acid is the acid diethyldithiophosphoric acid, diisopropyldithiophos-phoric, dicycloexyldithiophosphoric acid or dicrésyldithiophosphorique acid. 7 - Phenate according to one of claims 1 to 6 characterized in that it has an alkaline value of at least 250 and contains 0.5 to 10% by weight and preferably 1 to 5% by weight phosphorus. 8 - Phenate according to one of claims 1 to 7 characterized in that the phenolic compound is an alkylphenol comprising one or more linear alkyl groups or branched in C1 to C30, the total number of carbon of the or alkyl groups being equal to or greater than eight. 9 - Phenate according to claim 8 characterized in that the alkylphenol is carbonated in sulfurized form. 10- Phenate according to one of claims 1 to 9 characterized in that the derivative of alkali or alkaline earth metal is an oxide or hydroxide. 11- Phenate according to one of claims 1 to 10 characterized in that the oxygenated promoter and an alcohol aliphatic or aromatic, an alkoxyalkanol, a glycol or an alkanolamine, preferably an aliphatic alcohol in C1 to C20 or their mixtures. 12- Phenate according to one of claims 1 to 11 characterized in that the nitrogenous promoter is chosen among ammonia, ammonium salts, amines primary, secondary or tertiary in C2 to C10 and their salts, polyamines, alkanolamines or nitro mineral compounds, preferably ammonia, carbonate and ammonium chloride, ethylenediamine, ethanolamine, diethanolamine or nitrate calcium. 13- Phenate according to one of claims 1 to 12 characterized in that the hydrocarbon solvent is a aliphatic or aromatic compound in C6 to C12 and preferably an aromatic compound, such as benzene, toluene, xylene, ethylbenzene and the compounds chlorinated aromatics. 14- Phenate according to one of claims 1 to 13 characterized in that the diluting oil is of a nature paraffinic or naphthenic. 15- Lubricating composition characterized in that it contains a lubricating oil of natural origin or synthetic and 0.5 to 40% by weight and preferably 1 to 10%
weight of a phenate according to claims 1 to 14. 16- Composition according to claim 15 characterized in that that it contains anti-wear additives, dispersant, antioxidant and polymers improving viscosity.