EP0002644B1 - Basic complex magnesium compounds and their application to the preparation of detergent dispersant additives for lubricating oils - Google Patents

Description

The present invention relates to new basic magnesium complexes and their application as intermediates for the manufacture of detergent-dispersant additives for lubricating oils.

It is known to use basic magnesium complexes to prepare dispersant additives for lubricating oils.

According to the American brevel no. 3,761,411, such complexes can be prepared by reacting magnesium with anhydrous methanol in the presence of a volatile aromatic solvent then carbonation of the solution with carbon dioxide. The disadvantage of such a process is that magnesium is an expensive product and difficult to handle; in addition, magnesium reacts on! methanol releasing hydrogen, which makes the process dangerous.

According to American Patent No. 3,878,116, it is also known to obtain alkaline earth metal sulfonates from basic alkaline earth metal complexes, according to a process consisting in preparing a complex by reaction of a alkaline earth metal, methanol and CO ₂ oxide, to emulsify said complex in the presence of a volatile solvent with an oil-soluble sulfonate, to remove methanol by distillation, to hydrolyze the medium to transform the complex into carbonate and then to dehydrate ; this sequence of operations is carried out a sufficient number of times to obtain a sulfonate of desired basicity.

Such a process is well suited to the preparation of barium or calcium sulfonates, since the barium and calcium oxides are products having a high basicity and good solubility in alcohols. On the other hand, as described, this process cannot make it possible to prepare magnesium sulfonates industrially even if active magnesium oxide is used; in fact, the processes of alkalinization with barium or calcium compounds used to prepare basic or superalkalinized detergent-dispersants cannot be modified simply for the preparation of detergents-dispersants containing magnesium, and this because of the low basicity and the low solubility of magnesium compounds.

The Applicant has found new magnesium complexes obtained from magnesium oxide, soluble in methanol, which can be isolated, optionally stored and used to prepare, in a particularly simple manner, oil-soluble detergent-dispersant compounds.

The new basic magnesium complexes, object of the invention, are characterized in that they are obtained by suspending in methanol, a compound based on "active" magnesium oxide, the amount of magnesium oxide "active" up to 10% of the weight of methanol, and subjecting said suspension to a carbonation operation using carbon dioxide at a temperature below 50 ° C, until the end of absorption of carbon dioxide .

In the present invention, the term “active” magnesium oxide will be used to mean magnesium oxide capable of reacting with methanol and carbon dioxide and which, after carbonation, is completely dissolved in methanol; this type of oxide can be obtained by gentle calcination of the basic magnesium carbonate, for example at a temperature of the order of 500 to 700 ° C for at least 3 hours; the specific surface of this type of oxide is greater than 80 m2 / g, and generally greater than 100 m2 / g.

This type of oxide, prepared by gentle calcination, will preferably be used to prepare the new complexes which are the subject of the invention.

It is however possible to use partially active magnesium oxides generally containing more than 50% of magnesium oxide soluble in methanol after carbonation; such oxides can be obtained by calcination of basic magnesium carbonate at a temperature above 700 ° C., and have a specific surface area less than that of the "active" oxides. Since such oxides are only partially soluble in methanol after carbonation, it will be necessary to remove the insoluble part before storage or use of the complexes which are the subject of the invention.

The new magnesium complexes which are the subject of the invention are difficult to describe precisely; they could correspond to a solution in methanol of a mixture of the following compounds:

The new complexes which are the subject of the invention are preferably stored at atmospheric pressure under an atmosphere of carbon dioxide; for stability problems, it is preferable to prepare them from suspensions containing not more than 8% of "active" magnesium oxide in methanol and more particularly from suspensions containing 3 to 7% of "active" magnesium oxide.

The carbonation operation can be carried out at atmospheric pressure or under carbon dioxide pressure; for a preferred embodiment of the invention, said operation is carried out under a carbon dioxide pressure of between 5 and 50 kg / cm2, and generally greater than 8 kg / cm2.

The present invention also relates to the application of said basic magnesium complexes for the manufacture of neutral or overbased detergent-dispersant additives for lubricating oils.

By way of example, mention may be made of the application of said complexes for the production of optionally sulfurized alkylphenates, alkylbenzenesulfonates, alkylsalicylates, alkylphosphonates, alkylthiophosphonates .... neutral or overalkalinated or overalkalinated alkenylsuccinimides containing more than 50 carbon atoms in their alkenyl chain.

Neutral detergent-dispersants can be prepared by simple addition of the said complexes to optionally sulfurized alkylphenols, alkylbenzenesulfonic, alkylsalicylic, alkylphosphonic, alkylthio-phosphonic acids, etc., followed by thermal decomposition of the said complexes, stripping with an inert gas. , hydrolysis ....

Similarly, overbased detergent-dispersants can be obtained by simple addition to neutral alkylphenates, alkylbenzene sulfonates, alkylsalicylates, alkylphosphonates, alkylthiophosphonates ... or to alkenyl succinimides, followed by decomposition of said complexes by thermal means, stripping with a gas. inert, hydrolysis ....

Said complexes forming the subject of the invention are very particularly suitable for the preparation of optionally sulfurized alkylphenates carrying one or more C ₆ ―C ₆₀ , preferably C ₉ C, _S alkyl substituents, of mass alkylbenzenesulfonates molecular greater than 300, neutral or overbased and overbased alkenylsuccinimides, the alkenyl radical of which contains at least 50 carbon atoms.

Neutral magnesium alkylphenates can be prepared in a particularly satisfactory manner by adding said basic magnesium complexes to a solution of optionally sulfurized alkylphenol in dilution oil, distilling methanol and heating the reaction medium to 150 ° -220 °. C to remove all traces of volatile products; the quantity of magnesium complex to be used corresponds to approximately 1 gram atom of magnesium for 2 phenolic OH groups.

The neutral alkylphenates thus obtained can be overbased by addition of basic magnesium complex at a temperature at least equal to that of methanol distillation, then heating of the reaction medium to 150-220 ° C to remove all traces of volatile products; this operation can optionally be carried out in the presence of alcohols with a boiling point of between 100 and 200 ° C. such as isobutanol, hexanol, 2-ethylhexanol; the amount of complex to be used is such that the ratio number of gram atoms of magnesium to be dispersed / number of gram atoms of magnesium of the neutral phenate is less than or equal to 4 and preferably between 2 and 3.

The neutral magnesium alkylbenzene sulfonates can be prepared in a manner analogous to that described above for the neutral alkylphenates from alkylbenzene sulfonic acid; the quantity of magnesium complex to be used corresponds to 1 gram atom of magnesium for 2 sulfonic acid groups; according to a variant of said process, the complex can be introduced into the sulfonic acid solution at the methanol distillation temperature.

The overbased magnesium alkylbenzene sulfonates can be prepared in a similar manner to that described for the overbased alkylphenates from neutral magnesium alkylbenzene sulfonates; the quantity of magnesium complex to be used is such that the ratio number of gram atoms of magnesium to be dispersed / number of gram atoms of magnesium of the neutral sulfonate is less than or equal to 8, preferably between 2 and 7. According to a variant of this process, alkalinized alkylbenzenesulfonates can be prepared by replacing all or part of the neutral magnesium sulfonates with neutral alkylbenzenesulfonates of calcium or barium.

The overbased alkenylsuccinimides can be prepared by adding said basic magnesium complexes to a solution of alkenylsuccinimide in dilution oil in the presence of an alcohol with a boiling point of between 100 and 200 ° C., optionally adding water. to disperse any gel particles that may form and heating the reaction medium to 180-220 ^° C. under 20 mm of mercury to remove the volatile products; the quantity of magnesium complex to be used corresponds to a ratio number of gram atoms of magnesium to be dispersed / number of gram atoms of alkenylsuccinimide nitrogen less than or equal to 3 and preferably between 1 and 2 .

The following examples are given for information only and cannot be considered as limiting the scope and spirit of the invention.

Example 1

• préparation de l'oxyde de magnésium actif A On calcine pendant 7 heures à 500°C, 496 g de carbonate de magnésium basique correspondant à la formule approximative (Mg CO₃)₄, Mg (OH)₂, 5 H₂O, on obtient 215 g d'un oxyde de magnésium A dont la surface spécifique est de 125 m2/g.
• - carbonation
  • a) 2 g de l'oxyde de magnésium A sont mis en suspension dans 60 g de méthanol et car- onatés à 25°C. L'absorption de gaz carbonique cesse au bout de 100 heures; la solution obtenue est parfaitement limpide.
  • b) 18 g de l'oxyde de magnésium A sont mis en suspension dans 470 g de méthanol et sont carbonatés sous une pression de gaz carbonique maintenue entre 10 et 11 kg/cm2; l'exothermie de la réaction fait passer la température du mélange de 22°C à 36°C. Au bout de 4 h de réaction, l'absorption de C0₂ cesse et le mélange est parfaitement limpide.

Complex preparation from active magnesium oxide

• preparation of active magnesium oxide A 496 g are calcined for 7 hours at 500 ° C. basic magnesium carbonate corresponding to the approximate formula (Mg CO ₃ ) ₄ , Mg (OH) ₂ , 5 H ₂ O, 215 g of a magnesium oxide A are obtained whose specific surface is 125 m2 / g.
• - carbonation
  • a) 2 g of magnesium oxide A are suspended in 60 g of methanol and carbonated at 25 ° C. The absorption of carbon dioxide ceases after 100 hours; the solution obtained is perfectly clear.
  • b) 18 g of magnesium oxide A are suspended in 470 g of methanol and are carbonated under a carbon dioxide pressure maintained between 10 and 11 kg / cm 2; the exothermic reaction increases the temperature of the mixture from 22 ° C to 36 ° C. After 4 hours of reaction, the absorption of C0 ₂ ceases and the mixture is perfectly clear.

The mixture is brought back by relaxation to atmospheric pressure and can then be kept in an airtight container indefinitely.

The prepared mixture contains 2% by weight of magnesium.

Example 2

Preparation of complex from commercial active magnesium oxide.

18 g of Maglite DE sold by Merk, the specific surface area of which is 140 m2 / g, are suspended in 470 g of methanol, then carbonated at room temperature under a CO ₂ pressure maintained between 10 and 11 kg / cm 2. A clear solution is obtained after three hours. The complex obtained contains 2% magnesium.

Example 3

Preparation of complex from commercial active magnesium oxide.

18 g of Ferrumag 170 marketed by Rhône-Poulenc, the specific surface of which is 170 m2 / g and containing more than 5% Mg (OH) ₂ , are suspended in 470 g of methanol, then carbonated at room temperature under a CO ₂ pressure maintained between 10 and 11 kg / cm2. After 6 hours, a solution is obtained containing 2.6 g of solids, in particular consisting of magnesium hydroxide, which are removed by filtration or centrifugation.

The complex obtained contains 1.85% magnesium.

Example 4

Preparation of complex from partially active magnesium oxide.

18 g of magnesium oxide with a specific surface of 25 m2 / g, obtained by calcination at 1000 ^° C. of basic magnesium carbonate, are suspended in 470 g of methanol.

Carbonate at room temperature under a carbon dioxide pressure maintained between 10 and 11 kg / cm2 for 7 hours; a solution is obtained containing 7.5 solids which can be removed by filtration or centrifugation. The complex obtained contains 1% magnesium.

Example 5

Preparation of complex from commercial active magnesium oxide.

37 g of Maglite DE are suspended in 470 g of methanol, then carbonization is carried out at ambient temperature under a CO ₂ pressure maintained between 10 and 11 kg / cm 2.

A clear solution is obtained after 4 hours of reaction. The complex obtained contains 4% by weight of magnesium.

Example 6

Preparation of a neutralized sulfurized magnesium alkylphenate.

In a 1 liter flask, fitted with a stirring system, a distillation head, a pouring bulb and a thermometric sheath,

• - 144 g de p-dodécylphénol sulfurisé (soit environ 0,5 groupe OH phénolique) contenant 5,7% de soufre
• - 100g d'huile 100 N comme huile de dilution.

We charge:

• - 144 g of sulfurized p-dodecylphenol (about 0.5 phenolic OH group) containing 5.7% sulfur
• - 100g of 100 N oil as dilution oil.

The apparatus is optionally placed under a CO ₂ sweep, then 300 g of magnesium complex prepared in Example 1 b) are poured in for 1 hour with stirring.

The methanol is distilled at the end of the addition of the complex, then the mixture is heated to 180 ° C. to remove all traces of volatile products.

250 g of neutral magnesium alkylphenate containing 2.4% magnesium are thus obtained.

Example 7

Preparation of an overbased magnesium alkylphenate.

The neutral product obtained in Example 6 is maintained between 70 and 80 ° C, then 300 g of magnesium complex prepared in Example 1 b) are introduced over 2 hours.

Methanol distills as the reagent is added.

Once the addition is complete, the product is heated for 1 hour at 180 ° C to remove all traces of volatile products.

260 g of a bright and fluid crude product are thus obtained which can be easily filtered using 18 g of oil and filter earth.

257 g of finished product are then obtained containing 4.2% of magnesium and 3.3% of CO ₂ .

Taking into account the 18 g of filtration oil and the 18 g of finished product which remain absorbed on the filter cake, it is found that 96% of the magnesium used is found in the finished product.

Example 8

Preparation of a sulfurized and overbased magnesium alkylphenate.

• - 144 g de p-dodécylphénol sulfurisé
• -200 g d'huile 100 N (au lieu de 100 g)
• - et 300 g de complexe préparé à l'exemple 1 b).

A neutral alkylphenate is prepared as in Example 6 from:

• - 144 g of sulfurized p-dodecylphenol
• -200 g of 100 N oil (instead of 100 g)
• - And 300 g of complex prepared in Example 1 b).

350 g of neutral phenate are obtained, to which 150 g of n-hexanol are added.

The temperature is maintained between 70 and 80 ° C. and then 900 g of complex prepared in Example 1 b) are introduced over 4 hours.

Distillation is carried out under vacuum (20 mmHg) for 1 hour at 180 ° C. to remove the volatile products.

421 g of a bright and fluid product are obtained, which are filtered using 30 g of oil and filter earth.

430 g of finished product are then recovered containing 5% magnesium, 4% CO ₂ and having a TBN of 230 mg. Taking into account the 30 g of filtration oil and the 20 g of finished product remaining on the filter cake, it is found that 94% of the magnesium is found in the finished product.

Example 9

Preparation of a neutral magnesium alkylbenzene sulfonate.

• -260 g d'acide alkylbenzène sulfonique AS 157 commercialisé par ESSO, de masse moléculaire moyenne de 465 g (ASTM D 855) et ayant un indice d'acide de 85 mg de KOH/g.
• - 140 g d'huile 100 N

In a 1 liter flask, fitted with a stirring system, a pouring funnel, a distillation head and a thermometric sheath, we load:

• -260 g of alkylbenzene sulfonic acid AS 157 marketed by ESSO, with an average molecular mass of 465 g (ASTM D 855) and having an acid number of 85 mg of KOH / g.
• - 140 g of 100 N oil

125 g of magnesium complex prepared in Example 5 and containing 4% magnesium are added over 30 minutes, the temperature of the medium going from 20 to 45 ° C.

Once the addition of the complex is complete, the mixture is heated to 140 ^° C. to remove the methanol and the water coming from the neutralization of the sulfonic acid.

405 g of neutral magnesium alkylbenzene sulfonate containing 1.2% magnesium are thus obtained.

Example 10

Preparation of an overbased magnesium alkylbenzene sulfonate.

200 g of 2-ethylhexanol are added to the mixture prepared in Example 9 and the temperature of the medium is adjusted to 70-80 ° C.

500 g of magnesium complex prepared in Example 5 are then introduced over 3 hours.

When the addition of complex is complete, the mixture is heated to 180 ° C. under 20 min of mercury to remove the alcohols present in the medium.

450 g of crude product are thus obtained which are filtered using 20 g of oil and 20 g of filter earth; thus recovering 450 g of light and shiny brown finished product, containing 5.2% magnesium and 5.5% CO ₂

Example 11

Preparation of an overbased magnesium alkylbenzene sulfonate.

To 204 g of a solution in dilution oil containing approximately 50% of neutral calcium alkylbenzene sulfonate containing 2.3% of calcium, 201 g of n-hexanol are added.

The mixture is maintained at 70-80 ^° C. and 300 g of magnesium complex prepared in Example 5 are introduced over 2 hours.

When the addition of complex is complete, the mixture is heated to 180 ° C under a pressure of 20 mm of mercury to remove the alcohols present in the medium.

This gives 230 g of crude product which is filtered on filter earth using 40 g of oil

250 g of product are obtained containing 1.93% of calcium, 4.35% of magnesium and 6% of CO ₂ .

Given that 40 g of oil were introduced for filtration and that 20 g of product remaining absorbed on the filter cake, it is found that 98% of the magnesium has been dispersed in the product.

Example 12

Preparation of an overbased alkenylsuccinimide.

• -200 g d'une solution à 1,5% d'azote d'un bis (polyisobutényl succinimide) dans 50% d'huile de dilution, succinimide dérivé de la tri- éthylènetétramine, et d'un anhydride polyisobutényl succinique d'indice d'acide de 74, obtenu par condensation de l'anhydride malé- ique et d'un polyisobutène de masse moléculaire voisine de 1000,
• - 100 g dè n-hexanol

In a 1 liter flask, fitted with a stirring system, a pouring funnel, a distillation head and a thermometric sheath, we load:

• -200 g of a 1.5% nitrogen solution of a bis (polyisobutenyl succinimide) in 50% dilution oil, succinimide derived from triethylenetetramine, and of an index polyisobutenyl succinic anhydride 74 acid, obtained by condensation of maleic anhydride and a polyisobutene with a molecular weight close to 1000,
• - 100 g of n-hexanol

The temperature is maintained between 70 and 80 ° C. and 190 g of magnesium complex prepared in Example 1 b) are introduced over one hour, then 30 g of water are added in 10 minutes after the end of the addition of the complex.

The mixture is then brought to 180 ° C. under 20 mm of mercury to remove the remaining methanol, water and n-hexanol.

210 g of a brilliant product, free from gels or sediments, containing 1.8% of magnesium and having an alkalinity of 105 mg of KOH / g are thus obtained.

Claims (8)

1. New basic complexes of magnesium characterised in that they are obtained by putting into suspension into methanol, a compound based on "active" magnesium oxide in a quantity not exceeding 10% by weight of "active" magnesium oxide in relation to the methanol, and subjecting the said suspension to a carbonation operation by means of carbonic gas at a temperature lower than 50°C until no more carbonic gas is absorbed.

2. New complexes according to claim 1, characterised in that the said compound, based on "active" magnesium oxide, that is used, is a magnesium oxide with specific surface higher than 80 m2/g.

3. New complexes according to claim 2, characterised in that the said compound, based on "active" magnesium oxide, that is used, is a magnesium oxide with specific surface higher than 100 m2/g.

4. New complexes according to claim 1, characterised in that the said compound based on "active" magnesium oxide contains more than 50% by weight of "active" magnesium oxide.

5. New complexes according to any one of claims 1 to 4 characterised in that the quantity of "active" magnesium oxide used does not exceed 8% by weight of methanol.

6. New complexes according to claim 5, characterised in that the quantity of "active" magnesium oxide used is between 3 and 7% of the weight of methanol.

7. New complexes according to claim 1, characterised in the carbonation operation is carried out under a pressure of carbonic gas of between 5 and 50 kg/cm2.

8. Application of the new complexes object of any one of claims 1 to 7 for the manufacture of detergent-dispersant additives for lubricating oils.