EP0016676B1 - Process for the preparation of magnesium alkyl phenates - Google Patents

Abstract

A method of preparing magnesium alkylphenates comprising: 1. preparing a suspension of "active" magnesium oxide in methanol; 2. contacting said suspension with a mixture containing (a) an alkylphenol bearing one or more C6-C60 alkyl substituents; (b) a dilution oil; (c) and optionally a heavy alcohol of a boiling point of between 100 DEG and 200 DEG C., the ratio of number of mols of "active" magnesium oxide to number of recurrent phenolic OH units being between about 0.25 and 2; and 3. carbonating the resultant medium under pressure with carbon dioxide. The magnesium alkylphenates thus obtained are suitable detergent-dispersant additives for lubricating oils in amounts of between about 1 and 8 percent of the weight of the oils.

Description

The present invention relates to a process for the preparation of magnesium alkylphenates, the products obtained according to the process and the application of said products as detergent-dispersant additives for lubricating oils.

It is known from US Pat. Nos ^. 3,718,589 and 3,932,289 to prepare magnesium alkylphenates from alkylphenols, using carbonated magnesium alcoholates as neutralizing or over-alkalizing agents. Such processes are expensive and delicate because the carbonated magnesium alcoholates are prepared from metallic magnesium.

It is also known from French Patent No. 2,277,145 to prepare magnesium alkylphenates by carbonation of a mixture containing an optionally sulfurized alkylphenol, a suffonic acid, an alcohol, magnesium hydroxide or magnesia active as well as a promoter of the ammonium salt type of carboxylic acid.

Such a process uses not an alkylphenol alone but an alkylphenol-sulfonic acid mixture which is easier to neutralize and requires the presence of a promoter.

The Applicant has found a process making it possible to prepare magnesium alkylphenates using an alkylphenol alone (that is to say not mixed with a sulfonic acid), active magnesia and which does not require the use of a promoter.

• 1. On met en contact ladite suspension avec un mélange contenant :
  • - un alkylphénol portant un ou plusieurs substituants alkyles en C₆-C₆₀ ;
  • - une huile de dilution ;
  • - éventuellement un alcool lourd de point d'ébullition compris entre 100 et 200°C, le rapport nombre de moles d'oxyde de magnésium « actif »/nombre de motifs OH phénoliques étant compris entre 0,25 et 2, la quantité d'huile de dilution pouvant aller jusqu'à 140 % en poids par rapport au poids d'alkylphénol et le rapport molaire alcool lourd/oxyde de magnésium « actif étant compris entre 0 et 4, ledit rapport molaire étant d'au moins 1,2 lorsque le rapport nombre de moles d'oxyde de magnésium « actif »_/nombre de motifs OH phénoliques est supérieur à 0,75.
• 2. Et on carbonate sous pression le milieu obtenu à l'aide de gaz carbonique.
  Pour une bonne réalisation du procédé, on mettra en oeuvre préférentiellement :
  • - de 5 à 10 % en poids d'oxyde de magnésium « actif par rapport au poids de méthanol ;
  • - un rapport nombre de moles d'oxyde de magnésium « actif »/nombre de motifs OH phénoliques compris entre 0,5 et 1 ;
  • - de 20 à 75 % en poids d'huile de dilution par rapport au poids d'alkylphénol ;
  • - un rapport molaire alcool lourd/oxyde de magnésium « actif d'au moins 1,5 lorsque le rapport nombre de moles d'oxyde de magnésium « actif »/nombre de motifs OH phénoliques est supérieur à 0,75 ; et on réalisera l'opération de carbonatation pendant au moins 4 heures sous une pression comprise entre 3 et 30 kg/cm², plus particulièrement entre 5 et 15 kg/cm², avec une quantité de C0₂ correspondant, à plus ou moins 30 % en poids près, à celle pouvant être complètement absorbée par le milieu ; en général cette quantité de C0₂ correspondra sensiblement à celle pouvant être complètement absorbée.

The process for the preparation of magnesium alkylphenates, which is the subject of the invention from a suspension of magnesium oxide "active in methanol, said suspension possibly containing up to 10% by weight of oxide of “active” magnesium relative to the weight of methanol, said process being characterized in that

• 1. The said suspension is brought into contact with a mixture containing:
  • - an alkylphenol carrying one or more C ₆ -C ₆₀ alkyl substituents;
  • - a dilution oil;
  • - Optionally a heavy alcohol with a boiling point of between 100 and 200 ° C., the ratio number of moles of “active” magnesium oxide / number of phenolic OH units being between 0.25 and 2, the amount of dilution oil of up to 140% by weight relative to the weight of alkylphenol and the “heavy alcohol / magnesium oxide” active “molar ratio being between 0 and 4, said molar ratio being at least 1.2 when the number of moles of “active” magnesium oxide _/ number of phenolic OH units is greater than 0.75.
• 2. And the medium obtained is carbonated under pressure using carbon dioxide.
  For a good implementation of the process, preferably:
  • - from 5 to 10% by weight of magnesium oxide "active relative to the weight of methanol;
  • - A ratio number of moles of “active” magnesium oxide / number of phenolic OH units of between 0.5 and 1;
  • - from 20 to 75% by weight of dilution oil relative to the weight of alkylphenol;
  • - A molar ratio heavy alcohol / magnesium oxide “active of at least 1.5 when the number of moles of magnesium oxide“ active ”/ number of phenolic OH units is greater than 0.75; and the carbonation operation will be carried out for at least 4 hours under a pressure of between 3 and 30 kg / cm ² , more particularly between 5 and 15 kg / cm ² , with an amount of C0 ₂ corresponding to more or less 30 % by weight, to that which can be completely absorbed by the medium; in general, this amount of C0 _{2 will} correspond substantially to that which can be completely absorbed.

The term “active” magnesium oxide denotes magnesium oxide which 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 m ² / g and generally greater than 100 m ² / g.

The term “alkylphenol” denotes both non-sulfurized alkylphenols and sulfurized alkylphenols. Among the alkylphenols which can be used, mention may be made of those bearing one or more C ₉ -C ₁₅ substituents, in particular nonyl, decyl, dodecyl and tetradecylphenols, optionally sulfurized.

Among the dilution oils which can be used, mention may preferably be made of paraffin spikes such as 100 Neutral oil; naphthenic or mixed oils may also be suitable.

Among the heavy alcohols that can be used, mention may preferably be made of isobutanol, hexanol or 2-ethylhexanol.

The operation of suspending the “active” magnesium oxide in methanol takes place favorably at ordinary temperature. The contacting and carbonation operations can be carried out at a temperature between 0 and 40 ° C. preferably between 15 and 30 ° C.

The operations described above may optionally be followed by a water treatment operation, in particular when a ratio of the number of moles of “active” magnesium oxide / number of phenolic OH units greater than 1 has been set. in use and if one seeks to reduce the viscosity of the product obtained. This water treatment can be carried out in a conventional manner using 1 to 2 moles of water per mole of “active active” magnesium oxide.

Another subject of the present invention is the magnesium alkylphenates obtained according to the process described above, as well as the application of said alkylphenates as detergent additives. dispersants for lubricating oils. The amount of alkylphenates to be added to petrol engine oils is generally in the range of 1 to 4% by weight; that to be added in the oils for diesel engine is generally of the order of 1 to 8% by weight.

The lubricating oils which can thus be improved can be chosen from a wide variety of lubricating oils, such as the naphthenic base, paraffinic base and mixed base lubricant oils, other hydrocarbon lubricants, for example lubricant oils. derived from coal products, and synthetic oils, for example alkylene polymers, alkylene oxide type polymers and their derivatives, including alkylene oxide polymers prepared by polymerizing alkylene oxide in the presence of water or alcohols, for example ethyl alcohol, esters of dicarboxylic acids, liquid esters of liquid acids of phosphorus acids, alkylbenzenes and dialkylbenzenes, polyphenyls, alkylbiphenyl ethers, polymers of silicon.

Additional additives may also be present in said lubricating oils alongside the detergent-dispersants obtained according to the process of the invention; include, for example, anti-oxidant, anti-corrosion additives, ashless dispersant additives, etc.

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

Example 1

The alkylphenol used is presulfurized paradodecyl phenol (A) containing 11.5% of sulfur (obtained by sulfurization with sulfur).

The “active” magnesium oxide (B) used has a specific surface of 145 m ² / g and a purity of MgO of 90%.

The phenolic MgO / OH molar ratio used is 0.5.

The amount of active MgO is 9% relative to methanol.

The amount of dilution oil is 68.3% relative to the alkylphenol.

• - 146 g de paradodécyl phénol sulfurisé (A) (soit environ 0,5 mole de OH phénolique) ;
• - 100 g d'huile 100 Neutral de dilution.

In a one liter reactor resistant to pressures of 35 kg / cm ² and equipped with a stirring system, the following are charged:

• - 146 g of sulfurized paradodecyl phenol (A) (or approximately 0.5 mole of phenolic OH);
• - 100 g of 100 Neutral dilution oil.

A suspension of 11 g of the active magnesium oxide (B) (ie 0.25 mol) in 120 g of methanol is prepared separately and this suspension is added to the preceding mixture.

The mixture thus obtained is then carbonated at 20 ° C with stirring by introducing into the reactor carbon dioxide under a pressure of 10 kg / cm ² for 8 hours.

At the end of this time, the apparatus is brought back to atmospheric pressure and the methanol is removed by distillation while gradually raising the temperature to 180 ° C.

260 g of a sediment-free magnesium alkylphenate are thus obtained containing 2.3% magnesium, 2% CO ₂ , the apparent rate of over-alkalinization is 1 and having a TBN of 110 mg KOH / g (total Basic Number - Standard ASTM D 2 896).

Example 2 (Comparative)

We repeat Example 1 but without first preparing the suspension of magnesium oxide in methanol and by loading all the constituents of the mixture without special precautions.

After 8 hours of carbonation under 10 kg / cm ² of pressure and after elimination of the methanol we obtain a mixture still containing in suspension almost all of the charged magnesium oxide which makes the product infiltrable.

Example 3

The operation described in Example 1 is carried out in the presence of an amount of MgO "active corresponding to 5% by weight of methanol.

The suspension of “active MgO” thus consists of 11 g of active MgO (ie 0.25 mole) in 220 g of methanol.

270 g of sulfurized magnesium alkylphenate with a TBN of 90 mg are obtained, containing 2% magnesium and 1.8% C0 ₂

Example 4

• - active MgO / phenolic OH molar ratio used: 1;
• - amount of active MgO: 8.8% relative to the weight of methanol;
• - amount of dilution oil: 68.3% relative to the alkylphenol;
• - active hexanol / MgO molar ratio: 3.

• - 146 de paradodécyl phénol sulfurisé (A) (soit environ 0,5 mole de OH phénolique) ;
• - 100 g d'huile 100 Neutral de dilution ;
• - 150 g de n hexanol.

We charge:

• - 146 of sulfurized paradodecyl phenol (A) (ie approximately 0.5 mole of phenolic OH);
• - 100 g of 100 Neutral dilution oil;
• - 150 g of n hexanol.

A suspension of 22 g of active magnesium oxide (B) (i.e. 0.5 mol) in 250 g of methanol is prepared and this suspension is added to the preceding mixture.

The mixture is carbonated for 10 hours at room temperature under a pressure of 10 kg / cm ² of carbon dioxide.

At the end of this time the mixture is brought back to atmospheric pressure and the alcohols are removed by distillation by heating the product to 180 ° C. under vacuum to properly remove the hexanol.

270 g of crude product are thus obtained which are filtered through 20 g of filtration earth using 20 g of additional 100 Neutral oil.

270 g of finished product are thus recovered having a TBN of 170 mg and containing: 3.7% of magnesium and 3.5% of CO ₂ while 20 g of crude product remain absorbed on the cake. filtration.

Example 5

• - active MgO / phenolic OH molar ratio: 0.85;
• - active hexanol / MgO molar ratio: 1.5;
• - amount of active MgO: 8.6% relative to the weight of methanol;
• - amount of dilution oil: 68.3% relative to the alkylphenol.

• - 146 g du paradodécyl phénol sulfurisé (A) (soit environ 0,5 mole) de OH phénolique ;
• - 100 g d'huile 100 Neutral de dilution ;
• - 65 g de n-hexanol.

We charge:

• - 146 g of the sulfurized paradodecyl phenol (A) (ie approximately 0.5 mole) of phenolic OH;
• - 100 g of 100 Neutral dilution oil;
• - 65 g of n-hexanol.

A suspension of 19 g of active magnesium oxide (B) (i.e. 0.425 mole) in 220 g of methanol is prepared and we add this suspension to the preceding mixture.

The mixture is carbonated for 10 hours at room temperature under a pressure of 12 kg / cm ² of carbon dioxide.

It returns to atmospheric pressure, the volatile products are distilled by heating to 180 ° C. under vacuum.

270 g of crude product are recovered which are filtered through 20 g of filter earth using 20 g of additional dilution oil.

273 g of finished product are thus obtained having a TBN of 160 mg and containing 3.4% magnesium and 3% CO ₂ .

Example 6

• - active MgO / phenolic OH molar ratio: 0.5;
• - amount of active MgO: 8.66% relative to the weight of methanol;
• - amount of dilution oil: 45.5% relative to the alkylphenol.

• - 176 de paradodécyl phénol sulfurisé (A) (soit environ 0,6 mole en OH phénolique) ;
• - 80 g d'huile 100 Neutral de dilution.

We charge:

• - 176 of sulfurized paradodecyl phenol (A) (ie approximately 0.6 mole of phenolic OH);
• - 80 g of 100 Neutral dilution oil.

A suspension of 13 g of active magnesium oxide B (ie 0.3 mole) in 150 g of methanol is prepared and this suspension is added to the preceding mixture.

The resulting mixture is carbonated for 8 hours at room temperature under a pressure of 12 kg / cm ² of carbon dioxide.

Return to atmospheric pressure, distill the methanol and thus recover 278 g of a crude product which is filtered using 20 g of earth and 20 g of oil.

276 g of magnesium alkylphenate having a TBN of 110 mg and containing 2.3% of magnesium and 1.9% of CO _{2 are} recovered.

Claims (7)

1. Process for the preparation of magnesium alkylphenates from a suspension of « active magnesium oxide in methanol, the said suspension containing up to 10 % by weight of « active magnesium oxide, relative to the weight of the methanol, the said process being characterised in that :

a) the said suspension is brought into contact with a mixture containing :

- an alkylphenol carrying one or more C_s-C_so alkyl substituents ;

- a diluting oil and, if appropriate ;

- a higher alcohol with a boiling point between 100 and 200 °C, the ratio of the number of mols of «active magnesium oxide to the number of phenolic OH units being between 0.25 and 2, it being possible for the amount of diluting oil to range up to 140 % by weight, relative to the weight of alkylphenol, and the molar ratio of the higher alcohol to the « active magnesium oxide being between 0 and 4, the said molar ratio being at least 1.2 if the ratio of the number of mols of « active magnesium oxide to the number of phenolic OH units is greater than 0.75, and

b) the medium obtained is carbonated under pressure with the aid of carbon dioxide.

2. Process according to claim 1, characterised in that the following are used :

- from 5 to 10 % by weight of « active magnesium oxide, relative to the weight of methanol ;

― a ratio of the number of mols of « active » magnesium oxide to the number of phenolic OH units of between 0.5 and 1 ;

- from 20 to 75 % by weight of diluting oil, relative to the weight of alkylphenol ; and

- a molar ratio of the higher alcohol to the « active » magnesium oxide of at least 1.5 if the ratio of the number of mols of « active »magnesium oxide to the number of phenolic OH units is greater than 0.75 ; and in that the carbonation operation is carried out with an amount of CO₂ corresponding to that which can be completely absorbed by the medium.

3. Process according to claim 1 or claim 2, characterised in that the carbonation operation is carried out for at least 4 hours, at a pressure between 3 and 30 kg/cm² and at a temperature between 0 and 40 °C.

4. Process according to claim 3, characterised in that the carbonation operation is carried out at a pressure between 5 and 15 kg/cm², at a temperature between 15 and 30 °C and with an amount of CO₂ substantially corresponding to that which can be completely absorbed.

5. Process according to any one of the preceding claims, characterised in that the alkylphenols used carry one or more C₉-C_l5 alkyl substituents and may or may not be sulphurised.

6. Process according to any one of the preceding claims, characterised in that the higher alcohol used is isobutanol, hexanol or 2-ethylhexanol.

7. Process according to any one of the preceding claims, characterised in that the carbonation operation is followed by a treatment with 1 to 2 mols of water per mol of « active »magnesium oxide used, if the ratio of the number of mols of « active » magnesium oxide to the number of phenolic OH units is greater than 1.