EP0786448B1 - Process for producing a reaction product comprising a neutralisation step for alkylphenols and a carboxylation step for the obtained alkylphenate. - Google Patents

Description

The subject of the present invention is a process for preparing a product reaction which useful as additives detergent-dispersants for lubricating oils from type alkylsalicylates-alkylphenates, alkaline earth, sulfurized and overbased with improved properties foaming, compatibility and dispersion in oils and hydrolysis stability as well as the reaction product that may result from this process.

It is already known from US-A-3,036,971, published May 29, 1962, to prepare detergent-dispersant additives based on sulfurized metal alkylphenates alkaline earth of high basicity, by sulfurization of a alkylphenol, neutralization of sulfurized alkylphenol to using an alkaline earth base, then over-alkalinization by carbonation of the alkaline earth base dispersed in sulfurized alkylphenate; this type of product presents the disadvantage of being not very stable on hydrolysis, with formation precipitate of crystallized calcium carbonate, especially when this type of product is highly overbased, which leads to the risk of clogging the filters marine engines.

It is also known from the French patent 1,563,557, published April 11, 1969, to prepare additives detergents based on sulfurized calcium alkylsalicylates by carboxylation of a potassium alkylphenate, exchange with calcium chloride, then sulfurization of the alkylsalicylate of calcium obtained with sulfur in the presence of lime, a carboxylic acid and an alkylene glycol or alkylene glycol alkyl ether; such a process presents the disadvantage of requiring an exchange reaction.

a) neutralisation d'un alkylphénol à substituants alkyles en C₈ à C₃₀ par une base alcalino-terreuse, en présence d'un acide en C₁ à C₁₈ et d'un solvant formant un azéotrope avec l'eau de la réaction à une température correspondant à la température de reflux de l'azéotrope ;

b) distillation du solvant ;

c) carboxylation à l'aide de gaz carbonique sous pression pour transformer l'alkylphénate en alkylsalicylate ;

d) sulfurisation et suralcalinisation par le soufre et une base alcalino-terreuse en présence d'un glycol et d'un tiers solvant, suivie d'une carbonatation ;

e) et enfin filtration.

Under these conditions, the applicant has described in French patent application 2,625,220, published on June 30, 1989, a process for the preparation of overbased detergent-dispersant additives based on alkylphenates and alkylsalicylates, which comprises the following steps :

a) neutralization of an alkylphenol with C ₈ to C ₃₀ alkyl substituents by an alkaline earth base, in the presence of a C ₁ to C ₁₈ acid and of a solvent forming an azeotrope with the water of the reaction at a temperature corresponding to the reflux temperature of the azeotrope;

b) distillation of the solvent;

c) carboxylation using carbon dioxide under pressure to convert the alkylphenate to alkylsalicylate;

d) sulfurization and over-alkalization with sulfur and an alkaline earth base in the presence of a glycol and a third solvent, followed by carbonation;

e) and finally filtration.

However, this process developed by the Applicant, and the products obtained by this process have several disadvantages.

First, in the neutralization step, the use of a solvent giving an azeotrope with water is necessary to obtain a conversion rate sufficient alkylphenol to alkylphenate.

The carboxylation step is carried out at high pressures generally between 5 and 15 × 10 ⁵ Pa to convert the alkylphenate to alkylsalicylate.

And the step of sulfurization and over-alkalization is dangerous from an industrial point of view because it gives rise to a brutal release of hydrogen sulfide that could not be not master.

Finally the products obtained by this process previous have dispersion and compatibility with lubricating oils below those of alkylsalicylates, having the same metal content alkaline earth and above all, showed stability poor at hydrolysis, requiring frequent changes filters used in the lubrication circuits of marine engines.

A) Neutralisation d'alkylphénols contenant au moins 35 % et au plus 85 % en poids d'alkylphénol linéaire dans lequel le radical alkyle linéaire contient 12 à 40, et de préférence 18 à 30 atomes de carbone, en mélange avec au maximum 65 % et d'au minimum 15 % en poids d'alkylphénol ramifié dans lequel le radical alkyle ramifié contient 9 à 24 et de préférence 12 atomes de carbone, à l'aide d'une base alcalino-terreuse, en présence d'au moins un acide carboxylique contenant de 1 à 4 atomes de carbone, ladite opération de neutralisation étant effectuée à une température d'au moins 215°C, avec mise progressive sous vide du réacteur dans lequel s'effectue la réaction de neutralisation, afin d'éliminer l'eau de la réaction , en l'absence de tout solvant pouvant former un azéotrope avec cette dernière. Les quantités de réactifs mises en oeuvre correspondent aux rapports molaires suivants :

• base alcalino-terreuse/alkylphénol total compris entre 0,2 et 0,7 et, de préférence, entre 0,3 et 0,5,
• acide carboxylique total/alkylphénol total compris entre 0,01 et 0,5 et, de préférence, entre 0,03 et 0,15 ;

B) Carboxylation de l'alkylphénate obtenu dans l'étape A) pour transformer au moins 22 % et, de préférence, au moins 25 % en moles des alkylphénols de départ en alkyl-salicylate (mesuré en tant qu'acide salicylique), par action du gaz carbonique, à une température comprise entre 180 et 240°C, de préférence comprise entre 190 et 220°C, sous une pression pouvant aller de la pression atmosphérique à 15 x 10⁵ Pa (15 bars), pendant une durée d'une à huit heures, en présence éventuellement d'une huile de dilution (100 N par exemple) ajoutée au début ou à la fin de l'étape A ou de l'étape B ;

C) Sulfurisation et suralcalinisation du mélange d'alkylphénate et d'alkylsalicylate obtenu par du soufre élémentaire, en présence d'une base alcalino-terreuse, d'un mono-alcool ayant un point d'ébullition supérieur à 150°C, et de préférence supérieur à 175°C, et éventuellement à ce stade d'un alkylène-glycol ou d'un alkyléther d'alkylène-glycol à une température comprise entre 145 et 180°C, de préférence entre 150 et 160°C. Les quantités de réactifs mises en oeuvre correspondent aux rapports molaires suivants :

• soufre/alkylphénol total compris entre 0,3 et 1,5 et, de préférence entre 0,8 et 1,0 ;
• base alcalino-terreuse totale/alkylphénol total compris entre 1,0 et 3,5 et, de préférence, entre 1,4 et 3,0 ;
• base alcalino-terreuse totale/mono alcool de point d'ébullition supérieur à 150°C compris entre 0,3 et 0,5

   puis, après addition de l'alkylène-glycol ou son alkyléther s'il n'a pas été déjà ajouté dans un rapport molaire base alcalino-terreuse totale/alkylène-glycol compris entre 1,0 et 3,0 et, de préférence, entre 1,4 et 1,8, carbonatation du milieu obtenu par du gaz carbonique à une température de 145 à 180°C et sous pression voisine de la pression atmosphérique, la quantité de CO₂ utilisée étant comprise entre celle pouvant être complètement absorbée par le milieu réactionnel et un excès de 30 % de cette quantité;

D) Elimination de l'alkylène-glycol et du mono-alcool par distillation ;

E) Filtration pour éliminer les sédiments ;

F) et enfin dégazage à l'air à une température comprise entre 80 et 160°C, de préférence entre 100 et 140°C, jusqu'à ce que la lotation de la lame de cuivre soit 1A à l'essai selon la norme ASTM D-130, effectué pendant au moins 15 minutes à 150°C et de préférence 1 heure à 150°C.

The applicant has now found that it could substantially improve the performance of these additives, in particular in the foaming, compatibility and dispersion tests in a new oil and in the hydrolysis stability tests, by preparing them by a method comprising the following steps:

A) Neutralization of alkylphenols containing at least 35% and at most 85% by weight of linear alkylphenol in which the linear alkyl radical contains 12 to 40, and preferably 18 to 30 carbon atoms, mixed with at most 65% and at least 15% by weight of branched alkylphenol in which the branched alkyl radical contains 9 to 24 and preferably 12 carbon atoms, using an alkaline earth base, in the presence of at least one carboxylic acid containing from 1 to 4 carbon atoms, said neutralization operation being carried out at a temperature of at least 215 ° C, with progressive placing under vacuum of the reactor in which the neutralization reaction is carried out, in order to eliminate the water of the reaction, in the absence of any solvent capable of forming an azeotrope with the latter. The quantities of reagents used correspond to the following molar ratios:

• alkaline earth base / total alkylphenol of between 0.2 and 0.7 and preferably between 0.3 and 0.5,
• total carboxylic acid / total alkylphenol of between 0.01 and 0.5 and preferably between 0.03 and 0.15;

B) Carboxylation of the alkylphenate obtained in step A) to transform at least 22% and, preferably, at least 25% in moles of the starting alkylphenols into alkyl salicylate (measured as salicylic acid), by action of carbon dioxide, at a temperature between 180 and 240 ° C, preferably between 190 and 220 ° C, under a pressure which can range from atmospheric pressure to 15 x 10 ⁵ Pa (15 bars), for a period of one to eight hours, optionally in the presence of a dilution oil (100 N for example) added at the start or at the end of step A or of step B;

C) Sulfurization and over-alkalization of the mixture of alkylphenate and alkylsalicylate obtained with elemental sulfur, in the presence of an alkaline earth base, of a mono-alcohol having a boiling point above 150 ° C., and preferably above 175 ° C, and optionally at this stage of an alkylene glycol or an alkylene glycol alkyl ether at a temperature between 145 and 180 ° C, preferably between 150 and 160 ° C. The quantities of reagents used correspond to the following molar ratios:

• sulfur / total alkylphenol of between 0.3 and 1.5 and preferably between 0.8 and 1.0;
• total alkaline earth base / total alkylphenol of between 1.0 and 3.5 and preferably between 1.4 and 3.0;
• total alkaline earth base / mono alcohol with a boiling point above 150 ° C between 0.3 and 0.5

then, after addition of the alkylene glycol or its alkyl ether if it has not already been added in a total alkaline earth base / alkylene glycol molar ratio of between 1.0 and 3.0 and, preferably, between 1.4 and 1.8, carbonation of the medium obtained by carbon dioxide at a temperature of 145 to 180 ° C and under pressure close to atmospheric pressure, the amount of CO ₂ used being between that which can be completely absorbed by the reaction medium and a 30% excess of this amount;

D) elimination of the alkylene glycol and of the mono-alcohol by distillation;

E) Filtration to remove sediment;

F) and finally degassing in air at a temperature between 80 and 160 ° C, preferably between 100 and 140 ° C, until the lotation of the copper plate is 1A tested according to the standard ASTM D-130, performed for at least 15 minutes at 150 ° C and preferably 1 hour at 150 ° C.

a) les substituants alkyls dudit alkylsalicylate-alkylphénate sont dans une proportion d'au moins 35 % et au plus 85 % en poids d'alkyl linéaire dans lequel le nombre d'atomes de carbone est compris entre 12 et 40, de préférence entre 18 et 30 atomes de carbone, avec au maximum 65 % en poids d'alkyl ramifié dans lequel le nombre d'atome de carbone est compris entre 9 et 24 et de préférence 12 atomes de carbone,

b) en ce que la proportion de l'alkylsalicylate dans le mélange alkylsalicylate-alkylphénate est d'au moins 22 % et de préférence d'au moins 25 % en moles et

c) en ce que la proportion molaire de base alcalino-terreuse par rapport à l'ensemble alkyl salicylate-alkylphénate est compris entre 1,0 et 3,5.

According to another aspect, the subject of the present invention is also a detergent-dispersant additive for lubricating oil of the alkaline earth, sulphurized and over-alkalized alkylsalicylate-alkylphenate type, characterized in that

a) the alkyl substituents of said alkylsalicylate-alkylphenate are in a proportion of at least 35% and at most 85% by weight of linear alkyl in which the number of carbon atoms is between 12 and 40, preferably between 18 and 30 carbon atoms, with a maximum of 65% by weight of branched alkyl in which the number of carbon atoms is between 9 and 24 and preferably 12 carbon atoms,

b) in that the proportion of the alkylsalicylate in the alkylsalicylate-alkylphenate mixture is at least 22% and preferably at least 25 mol% and

c) in that the molar proportion of alkaline earth base relative to the alkyl salicylate-alkylphenate group is between 1.0 and 3.5.

The additives obtained according to the present invention may have a high basicity, reflected by the BN of these additives and measured according to ASTM-D2896 and which can easily reach values from 250 to 350 and even more.

It will be noted that the additives according to the invention are based on alkaline earth metals, to the exclusion of all alkali metal, such as in particular sodium and potassium.

The Applicant has found that the improvement of foaming, compatibility and dispersion properties and of hydrolysis stability of the additives thus obtained required the use of starting alkylphenols containing at least 35% and at most 85% by weight of alkylphenols in which the alkyl radical which contains from 12 to 40 atoms of carbon is linear and unbranched.

Indeed, it was conventional to use so far for the preparation of such additives alkylphenols in which the alkyl radical was generally a propylene tetramer, i.e. a dodecyl radical branched.

Now, the use of such a branched alkylphenol, insofar as it is present at more than 65% by weight in the starting alkylphenol, does not make it possible to obtain additives having the improved properties according to the invention;

Branched alkylphenols obtained by reaction phenol with a branched olefin containing 9 to 24 atoms of carbon and generally coming from propylene, consist in a mixture of monosubstituted isomers in very large majority in para position, very few in ortho position and practically not in the meta position, which makes them relatively reactive towards an alkaline earth base, since the phenol function is practically devoid of bulk steric.

On the other hand, the linear alkylphenols, obtained by reaction of phenol with a linear olefin containing 12 to 40 and preferably 18 to 30 carbon atoms and originating usually ethylene, consist of a mixture of isomers monosubstituted in which the proportion of substituents linear alkyls in ortho and para positions and even meta is much better distributed, which makes them distinctly less reactive towards an alkaline earth base, since the phenol function is much less accessible by following a large steric hindrance due to the presence closer and generally more alkyl substituents heavy.

It is all the more surprising, under these conditions, to be able to obtain alkaline earth additives overbased from mixtures of alkylphenol which may contain up to 85% by weight of linear alkyl radical in eliminating, in the neutralization step, the third solvent forming an azeotropic mixture with water and which was deemed essential up to now to react alkylphenols branched, more reactive, with alkaline earth base.

The Applicant has achieved this by maintaining in this first neutralization step the presence of a carboxylic acid which serves as a calcium transfer agent from a mineral reagent to an organic reagent and by providing more extensive reaction conditions, i.e. temperature of at least 215 ° C with a gradual setting of the vacuum reactor, so as to reach an absolute pressure very low at most 7,000 Pa (70 mbar) at this temperature to facilitate the removal of water.

Among the alkaline earth bases which can be implemented to carry out the different stages of preparation of the additives according to the present invention, it is possible quote oxides or hydroxides of calcium, magnesium, barium or strontium and especially those of calcium.

In the context of the present invention, slaked lime corresponding to the chemical formula Ca (OH) ₂ is preferred and will be used by way of illustration in the various examples under the name of lime.

Among the C ₁ to C ₄ carboxylic acids used in the neutralization step, mention may be made of formic, acetic, propionic and butyric acids, which can be used alone or as a mixture.

We prefer to use mixtures of these acids, for example the formic acid-acetic acid mixture, according to an acetic acid / formic acid molar ratio included between 0.01 and 5, preferably between 0.25 and 2 and all particularly of the order of 1, as described in particular in French patent 2,625,220, applied for on December 23, 1987 by the OROGIL Company.

As examples of suitable alkylene glycols for the sulfurization-over-alkalization stage, we can quote ethylene glycol, propylene glycol, butylene glycol.

Finally, among the monoalcohols having a point boiling above 150 ° C to be used in this same sulfurization-over-alkalization stage, we can cite the C6-C14 alkanols or cycloalkanols such as ethyl-2-hexanol, oxo alcohols, decyl alcohol, alcohol tridecylic, trimethylcyclohexanol; alkylene glycol ethers such as butoxy-2 ethanol, butoxy-2 propanol, hexyloxy-2-ethanol and the methyl ethers of dipropylene glycol.

The first neutralization step A) of alkylphenol is characterized by the use of a particular alkylphenol and reaction conditions, in particular of well determined temperature and pressure.

Indeed, the use of an alkylphenol having a content of at least 35% by weight and which can range up to 85% in linear alkylphenol, in particular in which the linear alkyl radical contains a significant number of carbon atoms (from 18 to 30 carbon atoms) is particularly interesting because a long alkyl chain linear promotes compatibility and solubility of additives in lubricating oils.

But the presence of linear alkyl radicals, relatively heavy, in alkylphenols, makes them less reactive than branched alkylphenols, hence the need to use more aggressive reaction conditions to neutralize them with an alkaline earth base.

The neutralization reaction is carried out at a temperature of at least 215 ° C, with progressive setting under vacuum, so as to reach a very low pressure of at most 7,000 Pa (70 mbar) at 215 ° C.

Step A) of neutralization can be carried out at a temperature of at least 220 ° C with progressive setting under vacuum, so as to reach a very low pressure of at most 7,000 Pa (70 mbar) at 220 ° C.

Particularly advantageous conditions of implementation consists in carrying out the neutralization step A) at a temperature of at least 225 ° C, with setting progressive under vacuum, so as to reach a very low at most 7,000 Pa (70 mbar) at 225 ° C.

According to another embodiment, the step of neutralization A) is carried out at a temperature of at least 240 ° C with progressive vacuuming, so as to reach a very low pressure of at most 7,000 Pa (70 mbar) at 240 ° C

At the end of this neutralization step, the alkylphenate obtained is preferably maintained for a period not exceeding 15 hours, generally between 2 and 6 hours, at a temperature of at least 215 ° C and a pressure absolute between 5,000 and 10 ⁵ Pa (0.05 and 1.0 bar), especially between 10,000 and 20,000 Pa (0.1 and 0.2 bar).

Indeed, under these conditions, it is possible to obtain, in the presence of the indicated proportion of C ₁ to C ₄ carboxylic acid, a transformation, at a sufficient rate, of the alkylphenol into the alkylphenate, which conditions the final content of the additive in alkaline earth metal and therefore its properties of detergent-dispersing agent in oils.

Provided that the temperature is sufficiently high high and carry out a gradual evacuation of the reactor, the neutralization reaction is carried out without that it is necessary to add in this step a third solvent forming an azeotrope with the water formed during this reaction.

The second carboxylation step B) aims to transform part of the alkylphenate into alkylsalicylate by simply bubbling carbon dioxide into the reaction medium from the previous step of neutralization. It must take place under pressure to avoid any decarboxylation of the salicylate that forms.

This carboxylation reaction of an alkylphenate containing at least 35% of relatively inert and heavy linear alkylphenate, requires heating to a temperature which must be higher the less the pressure in the reactor. Thus, if it is desired to limit the pressure in the reactor to 3.5 × 10 ⁵ Pa (3.5 bar) at most, it is advisable to operate at a temperature equal to or greater than 190 ° C.

According to a variant, step B) of carboxylation is carried out using carbon dioxide at a temperature equal to or greater than 200 ° C., under a pressure of 4 × 10 ⁵ Pa (4 bars)

During this carboxylation step, the transformation of the alkylphenate into an alkylsalicylate can involve the formation of alkylphenol, which should be convert to alkylphenate in the next step.

The third step (C) of the process for preparing the additives according to the present invention is divided into a reaction C ₁ of sulfurization and over-alkalization followed by a reaction C ₂ of carbonation.

The reaction C ₁ of sulfurization and over-alkalization is dangerous on an industrial scale because the addition of elemental sulfur to the reaction mixture at a temperature between 145 and 180 ° C results in a release of hydrogen sulfide which can only be controlled under certain conditions.

The Applicant has found that this reaction could be controlled after cooling the product obtained at the end of the carboxylation stage at around 155 ° C, by loading elementary sulfur at this temperature then gradually for a period of 1 to two hours, a mixture of the alkaline earth base, a mono-alcohol boiling point above 150 ° C, at a temperature of 150 to 160 ° C and possibly alkylene glycol.

Stopping the loading of this mixture results stopping the release of hydrogen sulfide.

Such an implementation of the reaction of sulfurization and over-alkalization allows to incorporate about 50 mole% of sulfur reacted in the alkylsalicylate-alkylphenate obtained, the remaining 50% being eliminated in the form of hydrogen sulphide.

To the extent that sulfur is used in a molar proportion of 0.5 to 1.5 or even 0.8 to 1.0 per compared to the total starting alkylphenol, this means that found in the alkaline earth alkylsalicylate-alkylphenate, sulfurized and overbased a molar proportion between 0.25 and 0.75, or even between 0.4 and 0.5.

lors de la neutralisation :

   où AA/AF désigne un mélange d'acide acétique et d'acide formique et où (II) est en proportion majoritaire et (I) en proportion minoritaire.

• lors de la carboxylation :
  
  
• et lors de la sulfurisation/suralcalinisation :
  

   en proportion majoritaire

   en proportion minoritaire Although the Applicant is not bound by any scientific explanation, it can be assumed that during the stages of the process for the preparation of the additives according to the present invention, the main chemical reactions are the following:

during neutralization:

where AA / AF denotes a mixture of acetic acid and formic acid and where (II) is in the majority proportion and (I) in the minority proportion.

• during carboxylation:
  
  
• and during sulfurization / over-alkalization:
  

in majority proportion

in a minority proportion

The carbonation reaction C ₂ by bubbling carbon dioxide in the reaction medium containing an excess of alkaline earth base relative to the alkylphenol which has reacted with sulfur at a temperature of 145 to 180 ° C. requires the presence of alkylene- glycol which must be added in this step C ₂ if it has not been added in C ₁ ; the purpose of this step C ₂ is to transform the additional alkaline earth base into alkylphenate and finely divided calcium carbonate, the latter being trapped between the sulfurized alkylphenate and alkylsalicylate molecules and thus causing the alkalinization of the additive .

The fourth stage of distillation D aims to eliminate the alkylene glycol and the mono-alcohol introduced into the reaction medium in the previous step to facilitate sulfurization, over-alkalization and carbonation of the additive according to the present invention.

The fifth filtration step E aims to get rid of sediments and especially carbonate crystallized calcium which could have formed during the stages which clogs the filters installed on the lubrication oil circuits.

Finally, the sixth and last degassing step to air F is important because it allows the additive to pass the hydrolysis stability test, which is not the case of an additive that would be manufactured exclusively at from a branched alkylphenol such as the dodecylphenol obtained by adding the propylene tetramer to phenol.

The present invention also relates to the method correspondent for the preparation of these additives and compositions lubricating oil, especially for marine engines, but also for cars and railways containing a major proportion of lubricating oil and from 2 to 20% in weight of a detergent dispersant additive according to the invention. These additives can also be used in applications industrial like hydraulic oils in proportions which vary from 0.1 to 3% by weight.

The following examples illustrate layouts particular work of the invention and are intended to assist the person skilled in the art for obtaining additives making the object of the present invention.

EXAMPLE 1

A) Neutralization : 875 g of dodecylphenol (DDP) of molecular weight 270, or (3.24 moles) and 875 g of linear alkylphenol, are charged to a 4 liter glass tetracol reactor, surmounted by a vigorous lagging. molecular weight 390 approximately (or 2.24 moles). The agitator is started and heated to 65 ° C; at this temperature, 158 g of lime Ca (OH) 2 (i.e. 2.135 moles) and 19 g of a mixture (50/50 by weight) of formic acid and acetic acid are added. Heating of the reaction medium is continued , at 120 ° C, temperature at which the reactor is placed under a nitrogen atmosphere, then up to 165 ° C, where the nitrogen atmosphere is stopped; At this temperature, the distillation of water begins. The temperature is raised to 220 ° C and a vacuum is gradually applied until an absolute pressure of 5,000 Pa (50 mbar) is obtained. the reaction mixture for 5 hours under the preceding conditions. It is allowed to cool to 180 ° C., then the vacuum is broken under a nitrogen atmosphere and a sample is taken for analysis. The total amount of distillate obtained is approximately 114 cm. ³ ; demixing occurs in the lower phase (62 cm ³ being water).

B) Carboxylation : The product obtained in step A) is transferred to a 3.6 l autoclave and heated to 180 ° C. at this temperature, and the reactor is started to sweep the reactor with carbon dioxide (CO2) for 10 minutes. The quantity of CO2 used in this step is of the order of 20 g. After having brought the temperature to 200 ° C., the autoclave is closed, leaving a minimal leak and the introduction of the CO2 is continued so as to maintain a pressure of 3.5 × 10 ⁵ Pa (3.5 bar) for 5 hours at 200 ° C. The amount of CO2 introduced is of the order of 50 g. After cooling the autoclave to 165 ° C., it is decompressed to atmospheric pressure and then purged with nitrogen. A total amount of product of 1916 g is recovered.

C1) Sulfurization and Suralcalinization : 1114 g of the product obtained in step B) are transferred to a 4 l tetracol glass reactor, equipped with a heating system and an agitator. introduced with stirring 487 g of 100 N oil and 0.2 g of antifoam. At 155 ° C., 90 g of sulfur (2.81 moles) are charged and a slight vacuum of 0.96 × 10 ⁵ Pa (960 mbar) is placed. In a beaker, a mixture of 193.6 g is prepared separately. of glycol, 273 g of lime and 589 g (including 200 of rinsing) of 2-ethylhexanol. The said mixture is added over 1 hour 30 minutes to the reactor while maintaining the temperature at 155 ° C. under the same slight depression. A release of hydrogen sulfide is observed. After introduction of the mixture, the temperature is increased to 170 ° C. in 1 hour and, during this step, 170 g of distillate are collected which separates into two phases, the lower phase of which contains water and glycol. One remains one hour under the above conditions, then it returns to atmospheric pressure.

C2 Carbonation : 101 g of carbon dioxide are introduced at a flow rate of 0.9 g / min (approximately). The total amount of distillate collected is 190 g, which separate into an aqueous phase of 100 g of a mixture of water and glycol and an organic phase of 90 g of 2-ethylhexanol.

D) Elimination of glycol and 2-ethylhexanol The mixture is heated to 195 ° C. while gradually vacuuming until an absolute pressure of 5,000 Pa (50 mbar) is obtained. final conditions above and a sample is taken to determine the percentage of raw sediment which is 1.2%.

E) Pressure filtration (4.10 ⁵ Pa at 150 ° C)

F) Air degassing : The above product is degassed in air at 110 ° C for 6 hours until a copper blade of 1A is obtained in the standardized test ASTM D 130 carried out under the conditions following: 15 minutes at 150 ° C.

The final additive obtained had the following characteristics: ANALYZES OF THE PRODUCT OBTAINED IN EXAMPLE 1: Calcium,% 9.1 Sulfur,% 2.25 BN ASTM D 2896 255 Viscosity at 100 ° C (in m ² / sx 10 ⁶ ) 100

EXAMPLE 2 :

A) Neutralization In a 5.1 reactor, 875 g of dodecylphenol (whose alkyl chain is propylene tetramer) are charged, 875 g of linear alkylphenol (the starting olefin being a linear alpha-olefin cut C ₂₀ -C ₂₈ from the company CHEVRON CHEMICAL), 158 g of lime and 22 g of a formic acid / acetic acid mixture (each of the 2 acids being equal in weight); the latter component must be added at a temperature of 80 ° C or less. The heating and the agitator are started and a light nitrogen sweep is carried out to expel the air from the reactor. At 170 ° C., the first drops of distillate appear. At 220 ° C., the nitrogen delivery is stopped and evacuation is started. The maximum vacuum is reached after about an hour and the product is left for 4 hours under the above conditions. The distillate collected consists of 2 layers, namely an upper layer of 60 cm ³ consisting mainly of alkylphenol and a lower layer of 80 cm ³ consisting mainly of water. After breaking the vacuum with nitrogen, the product is cooled to 200 ° C and a sample is taken to determine the percentage of sediment which is 2.8%.

B. Carboxylation The reactor is purged with CO 2 for 15 minutes then it is placed under a pressure of 3.5 × 10 ⁵ Pa (3.5 bar) of CO2 which is maintained for 5 hours under these conditions, before decompressing.

C. Sulfurization - Suralcalinization 800 g of the above carboxylated product are drawn off in another reactor and 350 g of oil are added. In a beaker, a mixture of 334 g of 2-ethylhexanol, of 139 g, is prepared separately with stirring. glycol and 196 g of lime. The reactor is started to heat. At 155 ° C., 64 g of sulfur (2 moles) are loaded, then after a waiting period of 10 minutes, the mixture is introduced. above by modulating the flow rate for 1 hour and a half so that the temperature variation is between 152 and 158 ° C. The reactor temperature is allowed to rise to reach 170 ° C. After the loading of the lime-containing mixture has finished, there are two hours of sulfurization. The introduction of CO2 is carried out in 1 hour 30 minutes at 170 ° C. The percentage of sediment is 1%.

D) Ethylene glycol and 2-ethylhexanol are eliminated by distillation. The final conditions are 1 hour at 195 ° C under 8,000 Pa (80 mbar). The percentage of sediment is 1%.

E) The product thus obtained is filtered under pressure.

F) The above product is degassed in air at 120 ° C for 6 hours. A sample is taken there to verify the ASTM D 130 copper blade test, carried out in following conditions: 15 minutes at 150 ° C.

The additive obtained has the following characteristics: % calcium 9 % sulfur 2.34 BN D 2896 261 salicylic acid index (mg KOH / g.) 33.6 Viscosity at 100 ° C (in m ² / sx 10 ⁶ ) 117 ASTM D130 copper blade 1a % Sedimentation (ASTM D 2273) (vol.) 0.02

EXAMPLES 3, 4, 5, 6 and 7 : STEP A): NEUTRALIZATION

• 87,5 Kg de dodécylphénol,
• 87,5 Kg d'alkylphénol linéaire (le même que celui utilisé dans l'exemple n°2)
• 15,8 Kg de chaux,
• 1,1 Kg d'acide formique
• 1,1 Kg d'acide acétique

In a 500 l reactor, the following are charged with stirring and in order:

• 87.5 kg of dodecylphenol,
• 87.5 kg of linear alkylphenol (the same as that used in Example 2)
• 15.8 Kg of lime,
• 1.1 Kg of formic acid
• 1.1 Kg of acetic acid

Formic and acetic acids are charged to a temperature below 80 ° C.

We start the reactor heating and we maintains at 220 ° C. As soon as this temperature is reached, begins to vacuum until pressure is obtained 6,000 Pa (60 mbar) which requires approximately 1 hour. The reactor is maintained for 4 hours under the above conditions then the vacuum is broken with carbon dioxide.

STEP B : CARBOXYLATION

The conditions are 5 hours at 200 ° C under a pressure of 3.5 x 10 ⁵ Pa (3.5 bar) of CO2.

The reactor is decompressed and cooled. The product is then transferred to a storage bin. A part of this product will be used for step C.

STEP C : SULFURIZATION - OVERCALINATION Charges :

• CARBOXYL PRODUCT: 80 Kg
• OIL 100N: 35 Kg
• 2-ETHYLHEXANOL 1: 33.4 Kg
• 2-ETHYLHEXANOL 2: 8.7 Kg
• LIME: 19.6 Kg
• GLYCOL: 13.9 Kg
• SULFUR: 6.5 Kg
• CO2: 7.5 Kg

The carboxylated product is loaded into the reactor and oil; it is stirred and heated.

Furthermore, we prepare in a separate container a premix of 2-ethylhexanol 1, glycol to which is added lime with stirring, in the proportions indicated above.

• A 155°C, on introduit dans le réacteur le prémélange, en 1 heure environ, puis la tuyauterie est rincée avec le 2-éthylhexanol 2.

When the temperature reaches 135 ° C, the reactor is placed under slight vacuum (96,000 Pa, or 960 mbar)

• At 155 ° C., the premix is introduced into the reactor, in about 1 hour, then the piping is rinsed with 2-ethylhexanol 2.

The reactor is then heated to 170 ° C. and is maintains for 2 hours under these conditions.

CO2 is finally introduced in 1 hour 30 minutes minutes.

STEP D :

Ethylene glycol and 2-ethylhexanol are eliminated by distillation. The final conditions are 1 h at 195 ° C under 6000 Pa (60 mbar).

STEP E :

The product is filtered at 150 ° C under a pressure of 4 bars. The percentage of sediment is 2.4%.

STEP F :

The above product is degassed in air at 120 ° C until obtaining a copper blade of rating 1A at ASTM D130 test, performed under the following conditions: 1 hour at 150 ° C.

n°3 - chauffage à 220°C puis mise sous vide.

n°4 - la mise sous vide commence à 180°C.

n°5 - minoration de la charge en chaux.

n°6 - minoration de la charge en chaux, la mise sous vide commence à 165°C.

n°7 - Idem n°6, mais un reflux est introduit en tête de la colonne menant du réacteur au condenseur afin de diminuer la perte en alkylphénol.

The main variant of tests 3, 4, 5, 6 and 7 is located in the neutralization phase.

n ° 3 - heating to 220 ° C then vacuum.

# 4 - vacuuming begins at 180 ° C.

n ° 5 - reduction of the lime load.

n ° 6 - reduction of the lime charge, the vacuum starts at 165 ° C.

# 7 - Same as # 6, but reflux is introduced at the top of the column leading from the reactor to the condenser to reduce the loss of alkylphenol.

The results of these tests are shown on the table I.

Example 8 STEP A : NEUTRALIZATION

• 87,4 Kg de dodécylphénol
• 87,4 Kg d'alkylphénol linéaire en C₂₀-C₂₈

On chauffe à 80°C puis on introduit 18 Kg de chaux (hydroxyde de calcium : Ca(OH2) ; on met sous agitation et on charge 0,53 Kg d'acide acétique et 0,37 Kg d'acide formique ainsi que 66 Kg d'huile 100 N. In a 500 L reactor, we load:

• 87.4 Kg of dodecylphenol
• 87.4 kg of linear C ₂₀ -C ₂₈ alkylphenol

The mixture is heated to 80 ° C. and then 18 kg of lime (calcium hydroxide: Ca (OH2)) are introduced; the mixture is stirred and charged with 0.53 kg of acetic acid and 0.37 kg of formic acid as well as 66 Kg of oil 100 N.

After heating to 220 ° C, gradually put under vacuum until a pressure of 5,000 Pa is obtained (50 mbar) and the above conditions are maintained for five hours.

STEP B : CARBOXYLATION

This phase is carried out under the conditions following: 200 ° C under a pressure of 3.5 x 10 Pa (3.5 bar) - duration: 7 h 00

STEP C : SULFURIZATION / OVERCALINATION

The process used is that described in the example n ° 1, with the exception of charges.

• 100 Kg du produit de l'étape B,
• 6 Kg d'huile 100N,
• 12 Kg de sulfonate de calcium de TBN environ 20
• 18 kg de chaux hydratée,
• 12,8 Kg de glycol,
• 5,6 Kg de soufre,
• 6,5 Kg de gaz carbonique,
• 23 Kg 2-éthylhexanol-1
• 15 Kg 2-éthylhexanol-2

These are from:

• 100 Kg of product from step B,
• 6 Kg of 100N oil,
• 12 Kg of calcium sulfonate of TBN about 20
• 18 kg of hydrated lime,
• 12.8 Kg of glycol,
• 5.6 Kg of sulfur,
• 6.5 Kg of carbon dioxide,
• 23 Kg 2-ethylhexanol-1
• 15 Kg 2-ethylhexanol-2

The other stages, D: Elimination of glycol and 2-ethylhexanol, E: Filtration and F: Degassing, are identical to that described in example n ° 1.

• calcium, % :   8,79
• soufre, % :   2,03
• BN D 2896 :   242
• viscosité à 100°C (m²/s x 10⁶) :   74
• % SED (Vol, %) ASTM D 2273 :   0,004
• Lame de cuivre ASTM D 130 :   1A

The analyzes obtained on the filtered and degassed product are as follows:

• calcium,%: 8.79
• sulfur,%: 2.03
• BN D 2896: 242
• viscosity at 100 ° C (m ² / sx 10 ⁶ ): 74
• % SED (Vol,%) ASTM D 2273: 0.004
• ASTM D 130: 1A copper blade

EXAMPLES 9, 10 and 11 : INFLUENCE OF SULFURIZATION TEMPERATURE

We operate under the same conditions as those described in steps A and B of Example 4 and we divide then in three equal fractions part of the product obtained at the end of stage B of carboxylation.

We then continue with all of the following steps as described in this same example 4, with the difference that in the first fraction (example 9) the sulfurization is carried out at a temperature of 165 ° C, in the second fraction (Example 10) at a temperature of 155 ° C and in the third fraction (Example 11) at a temperature of 145 ° C.

From an analytical point of view, as the results of the analyzes shown in the table show, no really significant difference is observed on the final product. EXAMPLE # 9 10 11 CONVERSION RATE (30%) (step B) C) SULFURIZATION / CARBONATION Sulfurization temperature (° C) 165 155 145 LOADS (g) carboxylate 1516 1516 1516 Sulfur 87.5 87.5 87.5 Lime 288 288 288 Glycol 194 194 194 2-Ethylhexanol 1 465 465 465 2-Ethylhexanol 2 120 131 119 CO ₂ 121 131 119 OIL 90 90 90 % GROSS SEDIMENTS 1.8 1.8 2.0 ANALYZES : % FILTERED SEDIMENTS (ASTM D2273) 0.2 0.12 0.08 Salicylic acid mg KOH / g 33 32 32 % Calcium 9.15 9.2 9.0 % Sulfur 2.3 2.35 2.3 BN D 2896 257 259 255 Viscosity 100 ° C (m ² / sx 10 ⁶ ) 103 93 90

EXAMPLE 12 :

The procedure is identical to Example 1, with this difference than in step C of sulfurization / carbonation, lime is added first and then glycol and ethylhexanol gradually.

From an analytical and performance point of view, no really significant difference is observed on the final product.

COMPARATIVE EXAMPLE 13

We repeat the experiment which is the subject of the example 7 of French patent 2,625,220 of the plaintiff, already cited previously.

The main characteristics of the process followed in this example are a mixture of alkylphenols containing 30% linear alkylphenol, neutralization temperature between 145 and 195 ° C and the use of 2-ethylhexanol as an azeotropic solvent.

The results obtained show that the temperature is too low to react so significant linear alkylphenols.

Similarly, we repeat the experiment which is the subject of Example 1 of patent US-A-4,902,436 from the company COSMO OIL.

Again the neutralization temperature, which was 160 ° C for 3 hours, did not allow the alkylphenols to participate meaningfully in the reaction with calcium oxide.

EXAMPLES 14 to 18

We carried out a series of examples 14 to 18 to determine the influence of the neutralization temperature, the latter being respectively 180 ° C. for Example 14, of 200 ° C for Example 15, 220 ° C for Example 16, 230 ° C for example 17 and finally 240 ° C for example 18.

The operating conditions and the results obtained in each of these examples 14 to 18, of which only the examples 16 to 18 represent implementations according to the present invention, appear in Table III below.

The operating conditions, with regard to Example 16 are specified in the description which follows.

EXAMPLE 16

A) Neutralization : 875 g of dodecylphenol (DDP) with a molecular mass of 270 (or 3.24 moles) and 875 g of linear alkylphenol are charged into a 4 liter glass tetracol reactor, topped with a vigorous lagging. molecular weight 390 approximately (2.24 moles) corresponding to a cut of C ₂₀ -C ₂₈ alpha olefins. The agitator is put at 350 revolutions per minute and heated to 65 ° C; at this temperature, 139 g of lime Ca (OH) 2 (i.e. 1.878 moles) and 18.9 g of a mixture (50/50 by weight) of formic acid and acetic acid (i.e. 0.36 mole) are added. heating of the reaction medium is continued at 120 ° C., the temperature at which the reactor is placed under a nitrogen atmosphere, then up to 165 ° C., where the nitrogen atmosphere is stopped; at this temperature, the distillation of water begins. The temperature is raised to 220 ° C in 1 hour, gradually vacuuming until an absolute pressure of 5,000 Pa (50 mbar) is obtained The reaction mixture is maintained for 3 hours under the preceding conditions. It is allowed to cool to 180 ° C., then the vacuum is broken under a nitrogen atmosphere and a sample is taken for analysis. The total amount of distillate obtained is about 94 cm ³ ; demixing occurs in the lower phase (51 cm ³ being water). 640 g of 100 N oil are then added.

B) Carboxylation : The product obtained in step A) is transferred to a 3.6 l autoclave and heated to 180 ° C. at this temperature, and the reactor is started to sweep the reactor with carbon dioxide (CO2) for 10 minutes. The quantity of CO2 used in this step is of the order of 20 g. After having brought the temperature to 200 ° C., the autoclave is closed, leaving a minimal leak and the introduction of the CO2 is continued so as to maintain a pressure of 3.5 × 10 ⁵ Pa (3.5 bar) for 6 hours at 200 ° C. The amount of CO2 introduced is of the order of 50 g. After the autoclave has cooled to 165 ° C., it is decompressed to atmospheric pressure and then purged with nitrogen. A total amount of product of 2513 g is recovered.

C) Sulfurization and Suralcalinization : 1516 g of the product obtained in step B) are transferred to a 4 l glass tetracol reactor, equipped with a heating system and a stirrer (600 revolutions per minute). on heating, 91 g of 100 N oil and 0.2 g of antifoam are introduced with stirring. At 110 ° C., 90.5 g of sulfur are charged and a slight vacuum of 0.96 x 10 is placed ⁵ Pa (960 mbar). In a beaker, a mixture of 193.6 g of glycol, 304 g of lime and 589 g (including 200 of rinsing) of 2-ethylhexanol is prepared separately. Said mixture is added over 1 hour to the reactor while maintaining the temperature at 155 ° C. under the same slight depression. A release of hydrogen sulfide is observed. After introduction of the mixture, the temperature is increased to 170 ° C. in 1 hour and, during this step, 170 g of distillate are collected which separates into two phases, the lower phase of which contains water and glycol. One remains one hour under the above conditions, then it returns to atmospheric pressure. Carbonation : 103 g of carbon dioxide are introduced at a flow rate of 0.9 g / min (approximately). The total amount of distillate collected is 220 cm ³ which separate into an aqueous phase of 90 cm ³ of a mixture of water and glycol and an organic phase of 130 cm ³ of 2-ethylhexanol.

D) Elimination of glycol and 2-ethylhexanol The mixture is heated to 195 ° C. while gradually vacuuming until an absolute pressure of 5,000 Pa (50 mbar) is obtained. final conditions above and a sample is taken to determine the percentage of raw sediment which is 1.6%.

E) Pressure filtration (4.10 ⁵ Pa at 150 ° C). A wire mesh filter and a filter aid are used.

F) Air degassing : The above product is degassed in air at 110 ° C for 16 hours until a copper blade of 1A is obtained in the standardized test ASTM D130 carried out under the following conditions : 60 minutes at 150 ° C.

The final additive obtained had the characteristics following:

ANALYZES OF THE PRODUCT OBTAINED IN EXAMPLE 16

calcium% 9.1 sulfur% 24 TBN ASTM D 2896 254 salicylic acid index (mg KOH / g.) 87 Viscosity at 100 ° C (in m ² / sx 10 ⁶ ) 26 mg KOH / g

EXAMPLES 19 to 22

We also carried out another series of experiments according to examples 19 to 22, which aimed to determine the influence of the relative proportion of alkylphenols linear in the mixture of starting alkylphenols.

This is how this proportion was 0% in Example 19, 20% in Example 20, 80% in Example 21 and 100% in Example 22. Only the Examples 16 and 21 form part of the invention.

The operating conditions were the same as those used in Example 16, described above, in which the relative proportion of alkylphenols in the mixture of alkylphenols at the outset was, let us recall, 50% in weight.

These conditions and the results obtained are shown in Table III below.

DESCRIPTION OF THE PERFORMANCE TESTS 1. HYDROLYSIS STABILITY: MAO 29

This method is inspired by the ASTM D method 2619 modified. Its purpose is to study sensitivity to the water of an oil and, is applicable to marine oils.

The method consists in introducing a sample oil with demineralized water in a bottle and to agitate it in a thermostatically controlled oven. At the end of the test, the sample is dried, filtered and analyzed. Stability at hydrolysis is expressed by: the presence or absence of carbonate crystallized, characterized by IR spectrometry. The results are qualified as "GOOD" in the absence of crystallized carbonate and "BAD" in the presence of this last.

2. MAO 60A DISPERSION :

The purpose of this method is to assess the properties dispersives of an oil or an additive and to predict its performance level (deposits, mud) compared to a reference oil.

It is generally applicable to motor oils terrestrial and marine.

Tache n°1

: température ambiante sans eau

Tache n°2

: 10 mn à 200°C sans eau

Tache n°3

: 10 mn à 250°C avec eau

Tache n°4

: température ambiante avec eau

Tache n°5

: 1 mn à 200°C avec eau

Tache n°6

: 10 mn à 200°C avec eau

According to this method, the dispersive power of the oil is obtained by carrying out a paper chromatography of a mixture of oil to be tested and of artificial mud under the following conditions:

Task n ° 1

: ambient temperature without water

Task n ° 2

: 10 min at 200 ° C without water

Task n ° 3

: 10 min at 250 ° C with water

Task n ° 4

: room temperature with water

Task n ° 5

: 1 min at 200 ° C with water

Task n ° 6

: 10 min at 200 ° C with water

The spots are observed after 48 hours of rest, manually or using the CCD photometer.

On each spot, we measure the diameter (d) of diffusion of the mixture and the diameter (D) of diffusion of oil only and the ratio d / D x 100 is calculated.

The dispersive power of the oil is obtained by comparing the sum of the 6 spots to the value found on one reference oils which should be tested in the same measurement series.

The addition of the d / D x 100 ratios in the six conditions listed above corresponds to a power maximum dispersive of 600, corresponding to a dispersion 100% ideal in all conditions. In the results the higher the number, the better the dispersive power of the oil.

3. MAO COMPATIBILITY 25

The purpose of this method is to assess the appearance and storage stability of additives and corresponding oils containing them.

This method is applicable to additives for lubricants.

In this method the additive and the corresponding oil the container are stored simultaneously at temperature ambient and hot for a specified period.

The appearance of the products is evaluated before and after storage and the results are classified as "GOOD" or "BAD" depending on whether or not a single phase is maintained without sedimentation deposit.

4. FOAMING

N° EXEMPLE 8 9 10 11 12 13 STABILITE MAO 29 BON BON BON BON BON MAUVAIS DISPERSION MAO 60A 330 333 333 333 333 335 COMPTABILITE MAO 25 BON BON BON BON BON MAUVAIS

The method used to determine whether a given compound gives rise to foaming is the standardized method ASTM-D 892, in which the lower the number, the better the product.

EXAMPLE # 8 9 10 11 12 13 MAO STABILITY 29 WELL WELL WELL WELL WELL BAD MAO 60A DISPERSION 330 333 333 333 333 335 MAO ACCOUNTING 25 WELL WELL WELL WELL WELL BAD

On reading the results obtained in the examples 14 to 18 intended to measure the influence of neutralization temperature, we can make comments following.

It appears that the salicylate content expressed in the form of salicylic acid index at the end of carboxylation step B increases with the temperature of neutralization to give the following respective results 12, 23, 26, 29 and 31 (mg KOH / g product).

On the other hand, it is clear that the neutralization temperature range (145'C - 195 ° C) used in the aforementioned French patent 2,625,220 is clearly insufficient for the neutralization of linear alkylphenol by lime. This is highlighted by the percentage of raw sediment (figure which accounts for the incorporation of lime) and the success or failure of the hydrolysis stability test, as shown in the table below: EXAMPLE # 14 15 16 17 18 Neutralization temperature 180 ° C 200 ° C 220 ° C 230 ° C 240 ° C SEDIMENT Vol,% (end of neutralization step) 8 3.6 2 0.8 1 MAO HYDROLYSIS STABILITY 29 BAD BAD WELL WELL WELL

There will also be a decrease in the foaming of the finished product when the neutralization temperature increases, this is explained by a greater reactivity of the alkylphenols linear at high temperature and it is known from a generally speaking that linear products are less foaming than branched products. In addition, spectroscopy infrared highlights a decrease in the content in orthoalkylphenols (mainly from the product linear) when the neutralization temperature increases.

On the other hand, on reading the results obtained in examples 19, 20, 16, 21 and 22, we can make the following comments.

a) à l'étape de neutralisation (A) :

• la quantité en poids totale d'alkylphénol ramifié et d'alkylphénol linéaire
• la quantité d'huile de dilution
• le rapport molaire : ACIDE ACETIQUE + ACIDE FORMIQUE ALKYLPHENOL
• et le rapport molaire : CHAUX ALKYLPHENOL

b) à l'étape de carboxylation (B) : la pression de CO2 et les autres conditions opératoires

c) à l'étape de sulfurisation et suralcalinisation (C) : les charges des différents réactifs et les conditions opératoires.

In the examples in question, only the proportion of linear alkylphenols in the starting mixture which included linear alkylphenols and / or branched alkylphenols varied, as shown in the table below: N ° EXAMPLES 19 20 16 21 22 ALKYLPHENOL LIN. / ALKYLPHENOL (LIN. + RAM.) X 100 in pds in moles 0
0 20
14.7 50
40.9 80
73.5 100
100 LINEN. = Linear
RAM. = Branched The other parameters that have been kept constant in these examples are:

a) in the neutralization step (A):

• the amount by total weight of branched alkylphenol and linear alkylphenol
• the amount of dilution oil
• the molar ratio: ACETIC ACID + FORMIC ACID alkylphenol
• and the molar ratio: LIME alkylphenol

b) at the carboxylation stage (B): the CO2 pressure and the other operating conditions

c) at the sulfurization and over-alkalization stage (C): the charges of the various reagents and the operating conditions.

• stabilité à l'hydrolyse MAO 29
• dispersion dans les huiles neuves MAO 60A ; plus le chiffre est élevé, meilleur est le produit.
• compatibilité MAO 25 (pass = bon, ou échec = mauvais).
• moussage ASTM D 892 - plus le chiffre est bas, meilleur est le produit.

The aim pursued in the choice of these different parameters for Examples 19, 20, 16, 21 and 22 was to obtain a product satisfying the following four performance tests:

• hydrolysis stability MAO 29
• dispersion in new oils MAO 60A; the higher the number, the better the product.
• MAO 25 compatibility (pass = good, or failure = bad).
• ASTM D 892 foaming - the lower the number, the better the product.

• Le BN ASTM D 2896 qui, après élimination de la chaux non réagie par filtration, rend compte de la basicité du Milieu.
• Le pourcentage de sédiment en volume, c'est-à-dire la chaux non réagie.
• La quantité d'eau recueillie qui provient de la réaction acide base : (Alkylphénol + chaux).
• La teneur en salicylate exprimée sous la forme acide salicylique mg KOH/g produit dans le produit final.

The results obtained in said examples can be summarized in the table below: N ° EXAMPLES 19 20 16 21 22 19 + 22/2 AP * LINEARIE / AP (LIN * + RAM *) x 100 (weight) 0 20 50 80 100 50 NEUTRALIZATION BN D 2896 139 109 103 60 13 76 SED (% Vol) 0.4 0.6 2 6 9 4.7 DISTILLED WATER (ml) 64 58 45 26 9 36.5 FINAL PRODUCT SALICYLIC ACID INDEX (mg KOH / g) 34 30 26 19 7 20.5 TEST RESULTS MAO HYDROLYSIS STABILITY 29 bad bad Well Well bad bad MAO 60A DISPERSION 295 311 333 337 318 309 MAO ACCOUNTING 25 bad bad Well Well Well bad FOAM D 892 SEQ 1 750/650 530/420 130/10 30/0 460/220 550/180 SEQ II 720/10 410/0 250/0 80/0 600/0 - SEQ III 600/460 580/370 150/0 45/0 400/60 - AP * = Alkylphenol
LIN * = linear
RAM * = branched First of all, we observe that the neutralization reaction is much more complete with branched alkylphenols than with linear alkylphenols, which is confirmed by the following 4 analyzes.

• BN ASTM D 2896 which, after removal of unreacted lime by filtration, gives an account of the basicity of the medium.
• The percentage of sediment by volume, i.e. unreacted lime.
• The amount of water collected which comes from the base acid reaction: (Alkylphenol + lime).
• The salicylate content expressed as salicylic acid mg KOH / g produced in the final product.

The above results were partly predictable because the branched alkylphenol of shorter chain therefore more reactive is made up mainly to 86% of the para isomer and 8% of the ortho isomer while the alkylphenol linear consists only of 45% of the isomer para and 55% of the ortho isomer. The neutralization of the ortho isomer is much more difficult due to steric hindrance.

However, there is an unexpected improvement MAO 29 hydrolysis stability and compatibility MAO 25 following an increase in linear alkylphenol as well as improved foaming and MAO dispersion 60A when the relative starting proportion goes from 0 to 80% of linear alkylphenols.

Example 20 in which the proportion of alkylphenol linear in the mixture of starting alkylphenols was only 20% by weight does not allow to obtain satisfactory results in the stability tests at MAO 29 hydrolysis and MAO 25 compatibility.

Additional tests have determined than the minimum proportion of linear alkylphenol in the mixture of starting alkylphenols must be at least 35% by weight to achieve satisfactory results overall tests appearing in the previous table and in particular those of MAO 29 hydrolysis stability and compatibility MAO 25.

On the other hand, we also observe, quite surprisingly, that the chemical mixture of linear and branched alkylphenols 50/50 by weight (example 16) has, with respect to the physical mixture: ALKYLPHENOL 100% RAM. (EX. 19) + 100% ALKYLPHENOL LIN. (EX 22) 2 unexpected analytical behavior, the results being significantly better, as shown by the results summarized in the table below: IN THE NEUTRALIZATION PHASE EXAMPLES 16 (19 + 22) / 2 BN 103 76 % SED 2 4.7 DISTILLED WATER (ml) 45 36.5 FINAL PRODUCT SALICYLIC ACID INDEX (mg KOH / g) 26 20.5 These performances of the 50/50 chemical mixture are all the more unexpected since the physical mixture does not pass the compatibility and hydrolysis stability tests, while the chemical mixture (example 16) passes them. In addition, in the foaming and dispersion tests an unexpected phenomenon is observed: the results improve when the level of linear alkylphenol increases to deteriorate markedly for the products with 100% linear alkylphenol. It is therefore necessary to admit a synergy between the simultaneous presence of linear alkylphenols and branched alkylphenols in the neutralization phase and on the performance of the finished products.

Although the plaintiff does not wish to be bound by any explanation, she offers the explanation following of the synergy between linear alkylphenol and branched alkylphenol.

During the neutralization stage, neutralization of linear alkylphenol is weak for the reasons following: low reactivity due to the length of the chain and to the preponderant presence of ortho isomer; in addition, from because of its high molecular weight, the training effect reaction water is weak. However, the introduction of a branched alkylphenol in the medium improves the rate of conversion of linear alkylphenol to alkylphenate for following reasons:

lequel étant plus basique que la chaux dans un milieu organique permet la neutralisation d'une 2ème mole alkylphénol R'-Ø-OH qui peut être linéaire.

The lime first reacts with a branched alkylphenol R-Ø-OH to yield the following product (I):

which being more basic than lime in an organic medium allows the neutralization of a 2nd alkylphenol mole R'-Ø-OH which can be linear.

In addition, the relative volatility of alkylphenol branched at this temperature facilitates the departure of water.

Another proof of the synergistic effect due to the presence of a mixture of branched alkylphenol and alkylphenol linear and observed at the lime neutralization stage is BN ASTM D 2896 which reports on the incorporation of lime, because this analysis is carried out after filtration, that is, removal of unreacted lime.

The table below gives the BN (ASTM D2896) obtained on the one hand for pure branched alkylphenol then for pure linear alkylphenol on the other hand for mixtures 20/80 50/50 and 80/20 by weight.

We observe that the more the linear fraction increases, the more the difference between the real BN and the theoretical BN (20/80, 50/50 and 80/20) increases. N ° EXAMPLES 19 20 16 21 22 LINEAR AP in% 0 20 50 80 100 AP BRANCHED in% 100 80 50 20 0 BN REAL NEUTRALIZATION PHASE 139 109 103 60 13 BN THEORETICAL 139 113.8 76 38.2 13 BN THEORETICAL / BN REEL 1 1.04 0.74 0.64 1

Claims (6)

1. A process for the preparation of a reaction product, characterized in that it comprises the following steps:

   A) neutralisation of alkylphenols containing at least 35 wt. % and at most 85 wt.% of linear alkylphenol, in which the linear alkyl radical contains 12 to 40 carbon atoms, in mixture with a maximum of 15 wt. % of branched alkylphenol in which the branched alkyl radical contains 9 to 24 carbon atoms, using an alkaline earth base in the presence of at (east one acid selected from carboxylic acids containing 1 to 4 carbon atoms, said neutralisation operation being carried out at a temperature of at least 215°C, the pressure in the reactor in which the neutralisation reaction is carried out being reduced gradually below atmospheric pressure in order to remove the water of reaction, in the absence of any solvent that may form an azeotrope with the latter. The quantities of reagents used correspond to the following molar ratios:

   alkaline earth base/total alkylphenol between 0.2 and 0.7.

   total carboxylic acid/total alkylphenol between 0.01 and 0.5.

   B) carboxylation of the alkylphenate obtained in step A) in order to convert at least 22 mole % and preferably at least 25 mole % of the starting alkylphenols to alkylsalicylate (measured as salicylic acid) using carbon dioxide at a temperature of 180°C to 240°C, under a pressure which may range from atmospheric to 15 x 10⁵ Pa (15 bars) for a period of one to eight hours.
2. A process according to claim 1, characterized in that the linear alkyl radical of linear alkylphenol contains 18 to 30 carbon atoms.
3. A process according to any one of claims 1 and 2, characterized in that the linear alkyl radical of branched alkylphenol contains 12 carbon atoms.
4. A process according to any one of claims 1 to 3, characterized in that the quantities of reagents used correspond to the following molar ratios:

   alkaline earth base/total alkylphenol between 0.3 and 0.5.

   total carboxylic acid/total alkylphenol between 0.03 and 0.15.
5. A process according to any one of claims 1 to 4, characterized in that step B) is performed at a temperature comprised between 190° C and 220°C.
6. A reaction product, characterized in that it is capable of being prepared according to the process of any one of claims 1 to 5.