DE1039069B - Process for the preparation of mixtures of alkyl phenolates and alkyl salicylates which are suitable as lubricant additives and have a high content of a polyvalent metal - Google Patents

Description

GERMAN

According to a proposal not previously published, suitable lubricant additives can be used Mixtures of alkyl phenolates and alkyl salicylates with a high content of a polyvalent one Manufacture metal by mixing mixtures of alkali salts of corresponding alkylsalicylic acids and Alkali salts of alkylphenols with an inorganic salt of a polyvalent metal and a Oxide or hydroxide of the polyvalent metal in the presence of an organic polar solvent implements.

It is also known basic salts of polyvalent metals of a very special oxyaromatic Acid, namely di-isopropylsalicylic acid, prepare by mixing the free acid with an excess of an appropriate metal compound brings to reaction, preferably working in an alcoholic medium. In this way of working however, it is not possible to obtain end products with basicities over 100%. The term "basicity" refers to the percentage excess of what is actually present in the end product Metal content compared to that portion of the polyvalent metal that is theoretically required for formation neutral salicylates is required.

It has now been found that the metal content and thus the basicity of mixtures of alkyl salicylates and alkyl phenolates suitable as lubricating oil additives can be increased considerably, while at the same time the phenolate content is advantageously reduced if the following process is used. According to the invention, mixtures of alkali alkyl phenolates and alkali alkyl salicylates are reacted in the presence of an organic solvent with an inorganic salt of a polyvalent metal and such amounts of an oxide or hydroxide thereof that are at least necessary for the formation of a salt with a basicity of 100%, based on the salicylate content of the starting mixture, theoretically required amount correspond. The starting material used is a mixture of phenates and salicylates which has been obtained by carboxylation of the corresponding alkali alkyl phenates in an anhydrous medium by treatment with carbon dioxide and subsequent aftertreatment of the carboxylation products with an alkali metal, alkali hydroxide or alkali alcoholate. The latter mixture of alkali alkyl salicylates and alkali alkyl phenolates may optionally have been carboxylated again before further reaction with an inorganic salt and an oxide or hydroxide of a polyvalent metal and after removal of the water and / or alcohol formed. Given method of manufacture
of as lubricant additives

suitable mixtures

from alkyl phenolates and alkyl salicylates with a high content of one

polyvalent metal

Applicant:

NV De Bataafsche Petroleum
Maatschappij, The Hague

Representative: Dr. K. Schwarzhans, patent attorney,
Munich 19, Romanplatz 9

Claimed priority:
Netherlands 29 October 1953

Mintje Van Loon and Jacob Groot,

Amsterdam, Netherlands),
have been named as inventors

if this, this reaction mixture originating from the second carboxylation can also be used before the further one Implementation of another post-treatment with an alkali metal, alkali hydroxide or alkali alcoholate have been subjected.

It is also possible that the second aftertreatment, after removal of the water and / or alcohol formed again, is followed by a third carboxylation, but such a three-time treatment with CO ₂ entails the risk of decarboxylation, especially in the case of substances with long alkyl groups salicylates already formed occurs.

It has been found that products are obtained when the procedure according to the invention is used whose basicity is particularly high and that even basicities of more than 200% are available. The term "basicity" is used here in the meaning already described. The theoretical one The polyvalent metal content can be determined by measuring the acid number of the product Release of the aromatic oxycarboxylic acids present therein.

309 6Ϊ8 / 435

To explain the particular technical effect achieved, it should be noted that the invention Process products likely contain disalts of alkyl salicylic acids. Be under it Compounds of the acids mentioned, in which both the hydrogen atom of the carboxyl group and the hydrogen atom of the phenolic hydroxyl group is replaced by a metal. Examples for such disalts are represented by the following structural formulas:

R- /

OCaOH

- COOCaOH

OCaOH OCaOH

_: - COO - Ca - OOC

Approx

- O

R -

COO - Ca - OOC -.

- R

Even if such a starting mixture of alkyl salicylates and alkyl phenolates is used comes in which a second carboxylation has taken place, the greater basicity is the one obtained Products attributed primarily to the presence of disalts of alkyl salicylic acids. In addition, the presence of a larger amount of salicylates can also be of influence, since these perhaps the peptization of free oxide or hydroxide of the polyvalent metal in the final product favor.

Although the process according to the invention is based on all types of phenolic compounds can come with consideration of the use of the mixtures obtained as lubricating oil additives especially phenols with one or more alkyl groups with 8 to 20 carbon atoms. The phenols are preferred prior to carboxylation converted into the sodium or potassium alkyl phenates, optionally a mixture of the two been.

The carboxylation product is preferably sodium or potassium, sodium or potassium hydroxide or after-treated with a sodium or potassium alcoholate, especially one Alcoholate derived from an aliphatic alcohol with 1 to 4 carbon atoms. Particularly Methanol is very suitable. You can also use mixtures of sodium and potassium or their hydroxides or Apply alcoholates.

The carboxylation can be carried out in a manner known per se, preferably at elevated pressure have been. A solution or suspension of the anhydrous alkali alkyl phenolate is expedient in an organic liquid such as toluene, xylene, tetrahydronaphthalene, liquid paraffin, dioxane, Pyridine or quinoline heated with carbon dioxide. In general, the results will be satisfactory at a temperature of 120 to 180 ° C and a pressure of 5 to 14 at. Under these conditions the first carboxylation action generally takes 3 to 5 hours.

After the first carboxylation has ended, an alkali metal, alkali hydroxide or alkali metal alcoholate is added to the reaction mixture, preferably in an amount of 0.9 to 2 gram equivalents per gram equivalent of the salicylate present in the reaction mixture. A suitable procedure is to treat the carboxylation product with a concentrated aqueous solution of an alkali metal hydroxide and this mixture by heating to a temperature of, for. B. 130 to 16O ⁰ C to hydrate under reduced pressure.

The final reaction with an inorganic salt of a polyvalent metal and an oxide or hydroxide of the polyvalent metal takes place in the presence of an organic solvent. Aliphatic alcohols with 1 to 3 carbon atoms in the molecule are preferred as solvents. The addition of the salt and the oxide or hydroxide can take place simultaneously or in succession. It can also be advantageous to let the oxide or hydroxide of the polyvalent metal arise in situ, for example by adding an alcoholic potassium hydroxide or sodium hydroxide solution _{to an alcoholic CaCl 2 solution.}

In the process according to the invention, such an amount of the oxide or Hydroxyds of the polyvalent metal too, how to obtain a product with a basicity of 150 to 300% is required. Usually this is 0.5 to 2 gram equivalents per gram equivalents Salicylate, which is present in the mixture, is required. If you want, you can still have one add larger amounts of oxides or hydroxides of the polyvalent metal.

The reaction of the mixture of the alkali alkyl salicylates and alkylphenolates with the added compounds of the polyvalent metal is generally possible at temperatures of 70 to 110 ° C smoothly in front of you, the upper reaction temperature of the boiling point of the organic solvent and optionally an additional diluent as well as the applied pressures. It is advantageous to use the solvent in question during slowly distill off the reaction from the mixture. The implementation is generally after Completed 1 to 4 hours. After the remaining solvent has been distilled off, the reaction product becomes of the alkali salts formed, e.g. B. NaCl, and optionally excess salt or hydroxide or oxide of polyvalent metal freed. This can be done in a simple manner by filtering off, preferably after diluting the reaction mixture with z. B. pentane, or by extraction with water or done with aqueous alcohol.

Surprisingly, the products produced according to the invention have a particularly light color.

The invention is explained in more detail by the following example.

example

a) Phenol was left with an im
Alkenes-1 with a chain length of
A mixture of atoms of matter in
from about 1.1 moles of alkenes to 1 mole
That obtained from this reaction
duct was obtained through treatment with

essentially from 14 to 18 carbons in a proportion of phenol react. Alkylation products or equivalents

Amount of sodium hydroxide (20% solution in methanol) converted into the corresponding sodium compound, the methanol being removed by distillation. The sodium alkylphenolates were then allowed to react _{with CO 2} at a temperature of 136 to 140 ° C. and a pressure which gradually fell to 36 to 20 atm. 67 mol percent of the alkylphenolates were converted into salicylates.

The mixture thus obtained of 67 mol percent sodium alkyl salicylates and 33 mol percent sodium alkyl phenolates was made with xylene in the ratio of 64 parts by weight of the mixture to 36 parts by weight Diluted xylene.

b) 400 parts by weight of the mixture of 67 mole percent sodium alkyl salicylates and 33 mole percent Sodium alkyl phenates containing 114 parts by weight of xylene were then prepared using those Execution of the new process, in which a second carboxylation takes place, treated further.

43.8 parts by weight of a 45% aqueous sodium hydroxide solution were used at room temperature to, which corresponds to 1.5 equivalents of NaOH per equivalent of salicylate present in the mixture.

The aqueous sodium hydroxide solution was added and the mixture became in a still to heated azeotropic removal of the water present therein. This treatment has been under regression of the xylene continued until the boiling point of the mixture remaining in the distillation column rose 145 ° C.

This mixture was then allowed to _{react in an autoclave with CO 2} at a temperature of 136 to 140 ° C. and at a pressure decreasing from 36 at to 20 at.

The product thus obtained was diluted with xylene to a xylene content of 41.5 percent by weight, whereupon it was allowed to react with calcium chloride and calcium oxide. Were stirring rapidly 400 parts by weight of the mixture obtained, which contained 166 parts by weight of xylene, heated to 75.degree. Then 247 parts by weight of a 20% strength by weight solution of calcium chloride in 96% strength were added Ethyl alcohol too, which is an excess of 5% with respect to the amount theoretically required to implement the sodium compounds present in the mixture into the corresponding calcium compounds is, corresponds. Immediately after the addition of the calcium chloride solution, 6.6 parts by weight of calcium oxide became added, corresponding to an amount of 0.65 gram equivalent per gram equivalent of salicylates present in the mixture. 146 parts by weight of a 96% strength ethyl alcohol solution were then added so that the total amount of the reaction mixture became 800 parts by weight.

The alcohol, the sodium chloride formed and the excess finally became the reaction product removed from calcium chloride and calcium oxide. In this way a product was obtained which has a Calcium content of 8.36 percent by weight and a basicity of 202%. The yield was Parts by weight (excluding solvent).

Claims (1)

PATENT CLAIM: Process for the preparation of mixtures of alkyl phenolates suitable as lubricant additives and alkyl salicylates having a high polyvalent metal content by reaction of mixtures of alkali alkyl phenolates and alkali alkyl salicylates with an inorganic one Salt of a polyvalent metal and an oxide or hydroxide of the polyvalent metal in the presence of an organic solvent, characterized in that mixtures of alkali alkyl phenolates and alkali alkyl salicylates implemented by carboxylation of alkali metal alkylphenolates in an anhydrous medium by treatment with carbon dioxide and subsequent post-treatment of the carboxylation products with an alkali metal, alkali hydroxide or alkali alcoholate, optionally removal of the water formed and / or alcohol and renewed carboxylation and optionally Post-treatment of the reaction mixtures originating from the second carboxylation with a Alkali metal, alkali hydroxide or alkali alcoholate have been obtained, and that the oxide or Hydroxide of the polyvalent metal is applied in an amount which is at least the theoretical Amount corresponds to the formation of a salt with a basicity of 100%, based on the salicylate content of the starting mixture is required. © »09 63S / 435 9.58