FR2656624A1 - - Google Patents

Abstract

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

Description

This invention relates to alkaline or alkaline earth phenates

  acid-rich, high-alkaline compounds containing an organic phosphorus derivative and their use in

lubricating formulations.

  The overbased phenates are alkali or alkaline earth metal salts of phenols overbased by carbonation with carbon dioxide. The overbased term is used to designate the excess of alkali or alkaline earth metal with respect to the stoichiometric amount.

  necessary to neutralize phenol.

  The structure of the overbased phenates is that of a colloidal dispersion whose micelles contain the alkali or alkaline earth metal carbonate formed during the carbonation. The micelles are stabilized by the alkaline or alkaline earth phenates which have a detergent effect. These overbased phenates are particularly useful in lubricants used in internal combustion engines of the "gasoline" or "diesel" type, whether they be

land or marine engines.

  Thanks to their detergent and dispersant effect they prevent the formation of lacquers and varnish on the pistons, and maintain in dispersion the soot resulting from the

  incomplete combustion of the fuel.

  Another important function of these additives is the neutralization of the acidic compounds resulting from the oxidation of the oil or the combustion of the sulfur-containing products brought by the fuel. This function is particularly appreciated when using sulfur-rich fuels as per example heavy fuels used in marine engines. The overbased phenates also improve the oxidation resistance of the oils in which they are incorporated. This property is more particularly marked when sulfurized phenols are used. This function is particularly appreciated for lubricating formulations subjected to severe thermal stresses, such as example in highly supercharged diesel engines The sulfurized overbased phenates are in the

  more used than their non-parous counterparts.

  The overbased phenates are characterized by their alkaline value (VA) expressed in mg of KOH per gram of product. It is determined by titration using a strong acid according to ASTM D-2896.

  significant alkalinity results in high VA.

  There exists in the prior art essentially two types of processes for the manufacture of phenates

overbased.

  European patent applications 0300486 and 0259974 describe a high temperature process, at about 1600 ° C. and at a pressure greater than atmospheric pressure. This process makes it possible to obtain alkaline-based overbased phenates only if an alkysulphonate is used. be associated with

  the alkylphenate during carbonation.

  French Patent 2305494 relates to a low temperature process, around 500 ° C. In the absence of an alkylsulphonate,

  the alkaline value of the phenates alone never exceeds 240.

  In addition, these products have the disadvantage of being

  unstable over time and have a high viscosity.

  These methods therefore do not allow the synthesis of

phenates with high alkaline value.

  It is also known to use in lubricants blends of overbased phenates and phosphorus or phosphorus-containing additives. These latter provide anti-wear and anti-oxidant properties. The most commonly used are the metal salts of dithiophosphoric acid and more particularly the sodium salt. zinc of

dialkyldithiophosphoric acid.

  Nevertheless, it turns out that negative interactions can exist between the overbased phenates and organic phosphorus derivatives, and in particular the zinc salt of dialkyldithiophosphoric acid Competition, during adsorption on the 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 the properties

antioxidant and antiwear.

  We have now found that by performing the carbonation of the phenates in the presence of an organic phosphorus compound, there is incorporation of phosphorus into the micelle, also containing the alkali metal or alkaline earth metal carbonate Thus the negative interactions between the overbased phenates and the organic phosphorus derivatives are surprisingly avoided, the carbonated overbased phenates in the presence of organic phosphorus derivatives, have an alkaline value greater than that of the overbased phenates of the prior art At the same time their stability is better and their viscosity sufficiently low

  so that no problem of manipulation appears.

  To our knowledge, the carbonation of an alkaline or alkaline earth phenate in the presence of an organic phosphorus compound is not described in the prior art. British Patent Application 2197336 relates to the addition of catalytic amounts of a dialkyl dithiophosphate. oil-soluble zinc, to an alkaline phenate, but it is a use as a sulfurization catalyst, in a two-stage process, comprising the sulfurization of phenol and its carbonation at the sulfurization temperature, between 145 and 1650 C, the dialkyldithiophosphate is decomposed into mercaptan and olefin, and in the carbonation stage the

  mixture no longer contains organic phosphorus.

  The invention therefore relates to an overbased alkaline or alkaline earth phenate, characterized in that it is obtained by carbonation of a mixture containing a phenolic compound, an organic phosphorus derivative, a derivative of an alkali metal or alkaline earth metal, a nitrogen promoter and / or oxygenated, a hydrocarbon solvent and optionally an oil

diluent and water.

  The overbased phenates obtained according to the invention are in the form of a clear, stable colloidal dispersion. Their alkaline value (VA) is greater than or equal to 250. The processes of the prior art did not make it possible to obtain phenates with a VA value. greater than 240 Higher values were obtained only with mixtures of

phenates and sulfonates.

  The presence of the organic phosphorus derivative confers on the overbased phenates according to the invention

  reinforced antioxidants as well as anti-wear properties.

  Among the organic derivatives of phosphorus, non-metallic compounds are preferably used. These non-metallic phosphorus organic compounds are chosen from phosphites, phosphoramides, phosphoric, thiophosphoric, dithiophosphoric, trithiophosphoric and tetrathiophosphoric acid derivatives and their salts.

organic.

  Phosphosulfur derivatives such as thiophosphoric or dithiophosphoric acids and their organic salts and preferably dithiophosphoric acid derivatives and their salts are more particularly used.

organic.

  Among the dithiophosphoric acid derivatives

  generally uses dihydrocarbyldithio-

  phosphoric, of general formula

R-O S

P (I)

R O SH

  o R and R ', which are identical or different, represent linear or branched alkyl chains in C 1 to C 20, the rings

aliphatic or aromatic.

  Among these derivatives we can mention the acid

  diethyldithiophosphoric acid, diisopropyldi

  thiophosphoric acid, dicyclohexyldithiophosphoric acid or

dicrésyldithiophophoric acid.

  It is particularly advantageous to use the

  compounds of general formula (I) insoluble in oils.

  These compounds have in addition to the antioxidant and anti-wear power, a surfactant effect Thus they participate as

  cotensioactives to the stabilization of micelles.

  The overbased phenates obtained according to the invention contain 0.5% to 10% by weight and preferably 1 to 5% by weight.

of phosphorus.

  To obtain this final concentration of phosphorus, the mixture to be carbonated must contain at least 3% of

  phosphorus as an organic derivative.

  The dihydrocarbyldithiophosphoric acids of general formula (I) can be prepared by the action of phosphorus pentasulfide on an alcohol or phenol of general formula 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 carried out at a temperature between and 200 C, depending on the type of alcohol or phenol

selected.

  The methods for preparing dialkyldithiophosphoric acids are described in the patents

  US 3089850, 3101096, 3293181 and 3489682.

  The phenolic compounds are generally alkylphenols, having one or more linear or branched C 1 -C 30 alkyl groups. To ensure the solubility of the corresponding alkali or alkaline earth metal phenols in the dilution oil, the total number of carbon atoms or

  alkyl groups must be equal to or greater than eight.

  The alkylphenols can be prepared by reacting an olefin or a mixture of olefins with phenol in the presence of a catalyst at a temperature

between 60 and 200 C.

  The alkylphenols used can be optionally sulfurized by the action of elemental sulfur at temperatures ranging from 150 to 200 ° C., or by the action of a

  sulfur halide such as mono or sulfur dichloride.

  The sulfurized product contains 1 to 1.5 sulfur atoms per phenolic nucleus, but its structure is not known with

precision.

  Among the alkali or alkaline earth metal derivatives, the oxides, hydroxides or alkoxides used are

  Preferred are oxides and hydroxides.

  These are added to the reaction medium in stoichiometric excess with respect to the excess phenolic compound.

  stochiometric can vary between 5 = 1 and 30 = 1.

  The oxygenated promoter is generally an aliphatic or aromatic alcohol, an alkoxyalkanol, a glycol or an alkanolamine. C 1 -C 20 aliphatic alcohols or mixtures thereof are preferably used. The aliphatic alcohols may be used in admixture with

  glycols, alkoxyalkanols or alkanolamines.

  The molar ratio of the oxygenated promoter to the phenolic compound is generally between 1 and 30.

  The use of a nitrogen promoter is optional.

  The nitrogen promoter is generally chosen from ammonia, ammonium salts, primary, secondary or tertiary C 2 -C 10 amines and their salts, polyamines or alkanolamines as well as nitrated mineral compounds. Among the nitrogen promoters, ammonia, ammonium carbonate and ammonium chloride, ethylenediamine, ethanolamine or diethanolamine, as well as nitrate of

calcium.

  The molar ratio of the nitrogen promoter to the compound

  phenolic is generally between 0.05 and 30.

  The hydrocarbon solvent allows a perfect homogenization of the various reagents as well as a lowering of the viscosity, which will subsequently facilitate the recovery of the solid residues of carbonation. The solvent generally represents 10 to 70% by weight of the reaction mixture. The solvents used are the compounds aliphatic or aromatic C 6 -C 12 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 the azeotropes they can form with the

oxygenates and water.

  The manipulation of the overbased phenates is facilitated by the addition of a diluent oil. The oil represents approximately 20 to 50% by weight of the additive obtained. This can be added to the reaction medium before or after the carbonation. that is to say just before the removal of solvents The diluent oils used are of paraffinic nature, type 100 or 150 Neutral Solvent or mainly naphthenic nature such as 100-150 Pale Solvent. The carbonation reaction can be carried out after the optional addition of water to the reaction medium. The addition of water is particularly advantageous when the alkali metal or alkaline earth metal derivative is an oxide. molar ratio

  water / metal oxide is of the order of 5.

  In more detail, the process for obtaining the phenates comprises: a, neutralizing the phenol compound, generally an alkylphenol or a sulfurized alkylphenol whose total number of carbons of the alkyl groups is equal to or greater than eight, by a metal derivative alkaline or alkaline earth, in the presence of a nitrogenous and / or oxygenated promoter and optionally a diluent oil a hydrocarbon solvent and water, b, add an organic derivative of phosphorus, preferably a nonmetallic derivative and better a phosphosulfur derivative, and then carbonate mixing with gaseous carbon dioxide for a time sufficient to consume partly or wholly the excess alkali metal or alkaline earth metal, c remove solid residues as well as solvents. A preferential implementation of the process consists in successively introducing into a reactor equipped with an agitator, a temperature regulation, a heating and evacuation system: 0 to 700 parts by weight of a hydrocarbon solvent, to 400 parts by weight of an alkylphenol or a previously sulfurized alkylphenol, an alkali or alkaline earth metal derivative in stoichiometric excess relative to phenol This stoichiometric excess is between 5 = 1 and 30 = 1, an oxygenated promoter whose molar ratio to phenol is between 1 and 30, optionally a nitrogen promoter whose molar ratio to phenol is between 0.05 and 30, optionally a quantity of water such that the molar ratio water / alkali metal oxide or alkaline earth metal is of the order of 0.5, a diluent oil in an amount such that it represents 20 to 50% by weight of the additive recovered at the end

operations.

  The neutralization reaction of the phenolic compound is carried out at a temperature of between approximately 30 and 0 ° C. and preferably at a temperature between

  and 1000 C for a period of about 0.5 to 4 hours.

  After this neutralization, the organic phosphorus derivative is added to the reaction medium. The phosphorus concentration of the reaction medium must be

greater than or equal to 3%.

  The carbonation of the stoichiometric excess of alkali metal or alkaline earth metal is then carried out at a temperature between room temperature and the reflux temperature of the mixture and more particularly at a temperature between room temperature and C and preferably at a temperature comprised between between 300 ° C. and 450 ° C. The molar ratio of the introduced carbon dioxide to the stoichiometric excess of alkali metal or alkaline earth metal is between 0.6 and 1.2. The mixture is optionally stabilized by heating under vacuum or under a stream of nitrogen. in order to remove low boiling oxygenated promoters and added water, as well as the water produced by the carbonation reaction. The solid residues are removed, generally by centrifugation and / or filtration.

using diatomaceous earth.

  If the diluent oil has not been added before carbonation, it is then added before the removal of the hydrocarbon solvent and optionally the alcohol. These are removed by heating under vacuum at temperatures of the order of 100 to 2000 ° C. The overbased phenates obtained according to the invention are brown in color and stable over time.

  is such that they can be handled at room temperature.

  They contain 0.5 to 10% by weight and preferably 1 to 5% of phosphorus. These overbased phenates are fully compatible with hydrocarbons They are incorporated in lubricating oils of natural or synthetic origin at a concentration of between about 0.5 and 40% by weight and

  preferably between 1 and 30% by weight.

  The lubricating compositions thus obtained may contain other additives, anti-wear, dispersant, antioxidant and viscosity index improvers. 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 ASTM D-2896.

  Unless otherwise indicated, all percentages are

in weight.

EXAMPLE A

  Preparation of Dimethyldithiophosphoric Acid In a 1 liter reactor equipped with a stirring system, a temperature control, a refrigerant and a reagent introduction system, coupled to a gas neutralization system The suspension is cooled to 3 ° C. and 153.6 g of methanol are added in the course of 0.5 hour, keeping the temperature below 100.degree. C., and the mixture is suspended in 600 ml of carbon tetrachloride. Then, in 1 hour and in portions, an excess of approximately 30% of methanol is added relative to the stoichiometry of the reaction. The mixture is then refluxed until it becomes perfectly clear. The solution is cooled and filtered on Millipore filter of

0.22 μm, then the solvent evaporated.

  177.6 g of 75.5% dimethyldithiophosphoric acid are recovered.

of purity.

EXAMPLE B

  Preparation of Diethyldithiophosphoric Acid One proceeds as in Example A except that one uses

  220.8 g of anhydrous ethanol instead of methanol.

  211 g of diethyldithiophosphoric acid at 95% purity are recovered.

EXAMPLE C

  Preparation of diisopropyldithiophosphoric acid The procedure is as in Example A except that it is used

288 g of isopropyl alcohol.

  243 g of 80% diisopropyldithiophosphoric acid are recovered.

of purity.

EXAMPLE D

  Preparation of dicyclohexyldithiophosphoric acid The procedure is as in Example A, except that it is used

  66.7 g of phosphorus pentasulfide and 240 g of cyclohexanol.

  209 g of 75% dicyclohexyldithiophosphoric acid are recovered.

of purity.

EXAMPLE E

  Preparation of dicrésyldithiophosphoric acid The procedure is as in Example A, except that 400 ml of toluene are used in place of carbon tetrachloride,

  66.7 g of phosphorus pentasulfide, and 259.2 g of para-cresol.

  401.2 g of 42% dicrésyldithiophosphoric acid are recovered

of purity.

EXAMPLE F

  Sulfurization of dodecylphenol In a 250 ml reactor equipped with a refrigerant, a temperature regulation and a gas sparger, 77.8 g of dodecylphenol and 20 g of sulfur chloride are introduced at a temperature of C. at 30 ° C. The mixture is heated under a nitrogen sweep and with stirring for 1 hour at

   C, then lh at 180 C and finally lh at 200 C.

  A sulfurized dodecylphenol is collected, the contents of which are

  chlorine and sulfur levels are 2200 ppm and 11.4% respectively.

  EXAMPLE 1 (Comparative) In a 250 ml reactor equipped with a condenser, a temperature regulation and a gas sparger device, 49 ml of the product of the example are successively introduced: F, 1 g of slaked lime at 96% purity ml of methanol 2.55 g of 20% ammonia The mixture is brought to reflux for 0.75 h before removal of the water produced by the neutralization of the dodecylphenol sulfurized On add 50 ml of methanol before carbonation with carbon dioxide of the stoichiometric excess of lime, at a temperature of 400 ° C. After carbonation, the residual water and methanol are removed by partial vacuum heating before recovering the residues. solids by filtration 30 g of oil are added

  diluent 100 Neutral before removing the solvent.

  A brown overbased sulfuric phenate is recovered from

  VA = 240 and a viscosity of 48 Pa s.

  EXAMPLE 2 (Comparative) In an assembly identical to that of Example 2, 90 ml of xylene are successively introduced into 43 g of the product of Example F 12 g of quicklime 66 ml of methanol 2 g of calcium nitrate then as in Example 2 and collects an overbased sulfurized phenoxide of VA = 245, with a viscosity of 115 Pa.s.

EXAMPLE 3

  The procedure is as in Example 1 with the difference that 16 g of the product of Example B is added just before the carbonation operation. The procedure is the same as in Example 1.

  except that residues are removed by centrifugation.

  The collected product is dark brown and its viscosity is Pa s Sa VA = 250 and its calcium and phosphorus contents

  are 8.6% and 2.2% respectively.

  This overbased sulfurized phenate containing a phosphosulfur compound is remarkably stable in dilution in

the oil after several months.

EXAMPLE 4

  The procedure is as in Example 3, except that 15 g of ammonium diethyldithiophosphate at 95% purity of JANSSEN CHEMICA are added in place of the product of Example B. An overbased sulfurized phenoxide of VA = is recovered. 255 whose calcium and phosphorus contents are 8.7% and 2.1% respectively The additive has a good stability in

  dilution in the oil after several months.

EXAMPLE 5

  The procedure is as in Example 2, except that 13 g of the product of Example B are added. The overbased sulfurized phenoxide collected at a VA = 250 and its viscosity is 70 Pa.s. The calcium and phosphorus contents of the additive are 8.1% and 2.1% respectively The product has a good stability in dilution in the oil after

several months.

EXAMPLE 6

  We operate as in Example 3 except that

  introduced 25 g of slaked lime into the initial mixture.

  An overbased sulfurized phenate of VA = 280 is recovered, the calcium and phosphorus contents of which are 9.7% and 2.1% respectively. The additive has a viscosity of 200 Pa.s and its

  Dilution stability in the oil is good.

EXAMPLE 7

  The procedure is as in Example 6 except that 48.5 g of the product of Example F is introduced into the initial mixture. An overbased sulfurized phenate of VA = 305 is recovered, the calcium and phosphorus contents of which are 10.6% and 2% respectively. The additive has a viscosity of 250 Pa.s and its

  Dilution stability in the oil is good.

EXAMPLE 8

  The performance of the new overbased phenates containing an organic phosphorus compound is examined in laboratory tests for stability, wear, detergency and oxidation. The test matrices correspond to lubricants for marine engines on the one hand and for engine

on the other hand.

  The products are first tested in simple dilution.

  Stability test (simple dilution) The tested products are diluted to VA = 70 and VA = 20 in a mixture of lubricating bases 600 Neutral Solvent / Bright Stock Solvent (20/80), the samples are placed in an oven at 600 ° C. and their stability is observed after one month. Table I shows that the new overbased phenates containing a phosphorus compound are perfectly stable in dilution whereas this is not the case for conventional overbased phenates prepared by a "low" process.

temperature".

TABLE I

  product of the example dilution stability

VA = 70 VA = 20

  1 (comparative) cloud-deposit deposition 2 (comparative) deposit filing 3) limpid limpid 4) limpid limpid) limpid limpid 6) limpid limpid 7) crystal clear limpid Wear test (lubricant for marine engine) The products are then tested in a lubricant formulation for marine engines (cylinder oil) The basicity of the oil is 70 mg KOH / g of which only 10 mg KOH / g provided by the sulfurized phenate overbased containing a

phosphorus compound.

  FALEX test The test is carried out under the following conditions: break-in: 5 minutes under 300 lbs (normal load) 3 hours of test under 900 lbs (normal load)

  These conditions are close to extreme pressure.

  Table II shows a significant reduction in wear with the overbased sulfurized phenoxide containing a phosphosulfur compound.

TABLE II

  Product example FALEX results wear (teeth) weight loss (mg) 1 (comparative) 32 29

3 3 5

  Wear test (lubricant for terrestrial diesel engine) Lubricating formulations for terrestrial diesel engine contain 2.8% of overbased phenate and 1.5% of phosphorus This phosphorus is provided on the one hand by the phosphosulfur compound, on the other hand by zinc dialkyldithiophosphate (DTPZ) FALEX test The test is carried out under the following conditions: burn-in = 5 minutes under 200 lbs (normal load) 3 hours test under 540 lbs (normal load) Table III shows that there is a significant reduction in wear.

TABLE III

  Product example FALEX results wear (teeth) weight loss (mg) 1 (comparative) 32 38

6 14 7.4

Claims (13)

  1 alkaline or alkaline earth based overbased phenate, characterized in that it is obtained by carbonation of a mixture containing a phenolic compound, an organic phosphorus derivative, an alkali metal or alkaline earth metal derivative, a nitrogen and / or oxygenated promoter, a hydrocarbon solvent and optionally an oil diluent and water.   2 Phenate according to Claim 1, characterized in that the mixture contains at least 3% of phosphorus in the form of organic derivative.   3 Phenate according to claims 1 or 2 characterized in   what the organic phosphorus derivative is a non-metallic compound, such as phosphites, phosphoramides and   derivatives of phosphoric acids.   4 Phenate according to claim 3 characterized in that the nonmetallic phosphorus derivative is a phosphosulfur derivative such as thiophosphoric acid, dithiophosphoric, trithiophosphoric or   tetrathiophosphoric acid and their organic salts.   Phenate according to Claim 4, characterized in that the dithioposphoric acid derivative is a dihydrocarbyldithiophosphoric acid of general formula R-O S P (I) RTO SH   o R and R ', which are identical or different, represent linear or branched C 1 to C 20 alkyl chains, the aliphatic or aromatic rings.   Phenate according to Claim 5, characterized in that the dihydrocarbyldithiophosphoric acid is the acid   diethyldithiophosphoric acid diisopropyldithiophos-   phoric, dicyclohexyldithiophosphoric acid or   dicrésyldithiophosphoric acid.   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 of phosphorus.   Phenate according to one of Claims 1 to 7, characterized   in that the phenolic compound is an alkylphenol having one or more linear or branched C 1 to C 30 alkyl groups, the total number of carbon of the alkyl group (s) being equal to or greater than eight. Phenate according to claim 8, characterized in that   the alkylphenol is carbonated in sulfurized form.   Phenate according to one of Claims 1 to 9, characterized   in that the alkali metal or alkaline earth metal derivative is an oxide, hydroxide or alkoxide, preferably a oxide or hydroxide.   Phenate according to one of claims 1 to 10   characterized in that the oxygenated promoter and an aliphatic or aromatic alcohol, an alkoxyalkanol, a glycol or an alkanolamine, preferably an aliphatic alcohol C 1 -C 20 or mixtures thereof.   Phenate according to one of Claims 1 to 11   characterized in that the nitrogenous promoter is chosen from ammonia, ammonium salts, C 2 to C 10 primary, secondary or tertiary amines and their salts, polyamines, alkanolamines or nitrated mineral compounds, preferably ammonia, carbonate and ammonium chloride, ethylenediamine, ethanolamine, diethanolamine or nitrate calcium.   Phenate according to one of claims 1 to 12   characterized in that the hydrocarbon solvent is an aliphatic or aromatic C 6 -C 12 compound and preferably an aromatic compound, such as benzene, toluene, xylene, ethylbenzene and the compounds chlorinated aromatics.   Phenate according to one of Claims 1 to 13   characterized in that the diluent oil is of a nature paraffinic or naphthenic.   Lubricating composition characterized in that it contains a lubricating oil of natural or synthetic origin and 0.5 to 40% by weight and preferably 1 to 10%   weight of a phenate according to claims 1 to 14.   Composition according to Claim 15, characterized in that it contains additives with anti-wear, dispersant, antioxidant effect and polymers. improving the viscosity.