JPH0243730B2 - KAENKISURUPPONSANKARUSHIUMUNOSEIZOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing overbased calcium sulfonate. Overbased calcium sulfonates, consisting of colloidal calcium carbonate dispersed in calcium sulfonate, have been known as lubricant additives for some time. Overbased calcium sulfonate acts as a dispersant and its basicity neutralizes the acids formed in the lubricant, thereby reducing corrosion. One problem with using overbased calcium sulfonates in lubricating oils has been the tendency of colloidal calcium carbonate to form haze and sediment in the oil. Additionally, such materials may be difficult to filter after manufacture. Various proposals have been made to overcome the above problems. For example, US Pat. No. 3,714,042 proposes reacting overbased calcium sulfonates with alkenylsuccinic acids or derivatives thereof.
This increases the cost of overbased calcium sulfonate and requires extra reactants and additional process steps. Overbased calcium sulfonates are generally prepared by carbonating a mixture of an oil-soluble sulfonic acid or alkaline earth metal sulfonate, an alcohol, often methanol, calcium oxide, and an oil. Certain processes use a second solvent, a cocatalyst, and an alkaline earth metal halide. A method for producing overbased calcium sulfonate is described in British Patent Specifications No. 1299253 and No.
It is also described in No. 1309172. The present inventors believe that the development of cloudiness and sediment in lubricating oil is due to the form of calcium carbonate.
The calcium carbonate present generally contains both crystalline and amorphous material, and the greater the amount of crystalline material present in the final product, the more difficult it is to filter and the more prone it is to clouding and sediment formation. It seems to be getting bigger. Therefore, the present invention comprises (i) (a) an oil-soluble alkylarylsulfonic acid or an alkaline earth metal salt thereof having a molecular weight of 300 to 700, (b) toluene, xylene or ethylbenzene as a solvent, and (c) a C ₁ to C ₅ alcohol ( d) oil (e) a mixture of calcium oxide in excess of that required for reaction with the sulfonic acid in a volume ratio of components (b) and (c) above of 30:70;
~80:20, the weight of component (a) is 40-220% by weight of the total weight of oil in the mixture, and the weight of components (b) and (c) is each 30-160% by weight of the total weight of oil in the mixture. (ii) adjust the water content between 0.50 and 4% of the weight of excess calcium oxide; (iii) until the PH of the mixture is in the range 6.0 to 7.5 and the infrared spectrum is 872 cm ^- at a temperature below the boiling point of the lowest boiling component of the mixture until it first shows the formation of vaterite as indicated by peak ¹ .
A method for producing an overbased calcium sulfonate is provided, comprising the steps of (i) carbonating the mixture; and (iv) removing volatiles. Component (a) of the reaction mixture includes oil-soluble sulfonic acids, which can be natural or synthetic sulfonic acids, such as mahogany or petroleum alkyl sulfonic acids, alkyl sulfonic acids, or alkaryl sulfonic acids. However, in the present invention, 300 to 700, preferably 400 to 500
An oil-soluble alkylaryl sulfonic acid having a molecular weight of is used, and an alkaline earth metal salt can also be used in place of the above sulfonic acid. Component (a) can be conveniently used as a solution in mineral oil, for example consisting of 70% by weight of sulfonic acid or sulfonate and 30% by weight of oil. Component (b) of the reaction mixture is an aromatic hydrocarbon solvent such as toluene, xylene, or ethylbenzene. Component (c) is preferably methanol, but other _C1 - _C5 alcohols such as ethanol, propanol, butanol, pentanol are used. Additional reaction co-catalysts may be used and these can be ammonium carboxylates as described in British Patent No. 1307172, preferred ammonium carboxylates being derived from _C1 - _C3 saturated monocarboxylic acids. such as formic acid, acetic acid,
or derived from propionic acid.
A preferred ammonium carboxylate is ammonium formate. Alkali metal salts of _C1 - _C3 carboxylic acids can also be used, preferred are the above-mentioned salts of _C1 - _C3 saturated monocarboxylic acids. Preferred alkali metals are sodium or potassium. Other promoters can be used, ie metal halides or sulfides. Preferred metals are alkali metals or alkaline earth metals such as sodium, potassium, lithium, calcium, barium, strontium. aluminum, copper,
Iron, cobalt, and nickel salts can also be used. The water content of the initial reaction mixture is important to obtain the desired product and should not be more than 4% by weight and should be at least 0.50% by weight, based on the weight of excess calcium oxide. Preferably, 1 to 3% by weight, based on the weight of excess calcium oxide, is used. Therefore, the reactants used, including carbon dioxide and calcium oxide which is subsequently added to the reaction mixture, are preferably anhydrous. When the reactants are not anhydrous, it is necessary to adjust the water level after formation of the reaction mixture to account for the water in each component and the water produced by neutralization of the sulfonic acid. In this case, (a), (b),
Preferably, the _C1 - _C5 alcohol is not added until the mixture of (d), (e) is formed. This is because the presence of alcohol at this stage can interfere with water removal. The reaction mixture is an oil solution of components (a), (b), (c) and (e), suitable oils being hydrocarbon oils, especially mineral ones, used as carriers. Oils having a viscosity of 15 to 30 centistokes at 100° are particularly suitable, and the lubricating oils described later herein can be used. Regarding the amounts of components (a), (b), (c), (d), and (e),
The capacity ratio of (b) and (c) is preferably 30:70 to 80:20
Too much component (b) will make the product greasy, while too much component (c) will make the reaction mixture too viscous during the addition of carbon dioxide and calcium oxide. The preferred capacity ratio of (b) and (c) is 50:50 to 70:30. If a cocatalyst is used, it is preferred to use up to 10% by weight, e.g. 3.0 to 7.0% by weight, based on the total weight of calcium oxide in the reaction mixture (i.e. including calcium oxide added at a later stage of the reaction). . The relative amounts of components in the reaction mixture are as follows: the weight of component (a) is 40% to 220% of the total weight of oil in the reaction mixture, and the weight of components (b) and (c) is each 40% to 220% of the total weight of oil in the reaction mixture. 30-160%, and if component (f) is added, it should be 4-15% by weight of the total weight of oil in the mixture. Calcium oxide can be added in batches, but the weight of each charge is preferably 20 to 30% by weight based on the combined weight of oil and component (a). The PH of the reaction mixture ranges from 6.0 to 7.5, as shown by monitoring with narrow range PH test paper;
Carbon dioxide is preferably introduced until the temperature is in the range of 6.5 to 7.0. Meanwhile, the infrared spectrum of the reaction mixture is monitored, and the reaction is stopped when a peak at 872 cm ^-1 appears in the spectrum corresponding to crystalline calcium carbonate. If carbonation were to continue at this point without removing methanol, the peak at 872 cm ^-1 would grow rapidly, while the peak at 865 cm ^-1 would fade, giving haze and sediment problems and producing a predominantly crystalline product. arise. When the PH of the reaction mixture is in the range of 6.5 to 7.0, a peak at 872 cm ^-1 tends to appear,
Also, when excess methanol is removed at this point and carbonation continues, the peak at 865 cm ^-1 is retained and 865
It was found that it gave a final product with both peaks at cm ^-1 and 872 cm ^-1 and did not suffer from haze and sediment problems. When carbon dioxide is being added, further calcium oxide may be added, if desired, up to a certain maximum amount, and carbon dioxide may be introduced into the reaction mixture in the same manner as described above. If sulfonic acid is used initially as component (a), it is not necessary to use as much calcium oxide as would otherwise be present in the reaction mixture before the first addition of carbon dioxide. However, in practice it is convenient to use the same amount of calcium oxide for each charge. If desired, a further addition of calcium oxide can be followed by addition of carbon dioxide using reaction conditions similar to the previous addition. In the further addition step, the carbon dioxide treatment in the previous step must be completed before adding calcium oxide. That is, the reaction mixture should no longer absorb carbon dioxide. After the final treatment with carbon dioxide, the reaction mixture must be heated to an elevated temperature, e.g. 130°C or above, to remove volatiles [component (b), water, and residual alcohol] and then filtered, generally using a filter aid. use a drug. The desired overbased detergent additive, usually having a TBN of 300 or more, is obtained as a filtrate. The overbased detergents of this invention are suitable for use in both mineral and synthetic lubricating oils. This lubricant can be animal, vegetable or mineral oil,
For example SAE30 from naphtha or spindle oil,
It can be a petroleum distillate, castor oil, fish oil, or oxidized mineral oil up to a lubricating oil grade of 40 or 50. Suitable synthetic ester lubricating oils include diesters such as dioctyl adipate, dioctyl sebacate, didecyl azelate, didecyl adipate, didecyl succinate, didecyl glutarate, and mixtures thereof. On the other hand, the synthetic esters are prepared by reacting polyhydric alcohols such as trimethylolpropane, pentaerythritol with monocarboxylic acids such as lactic acid, caproic acid, caprylic acid, pelargonic acid to obtain the corresponding tri- and tetraesters. It can be polyester. Complex esters, such as those formed by esterification reactions between dicarboxylic acids, glycols, alcohols, and/or monocarboxylic acids, can also be used as base oils. Blends of diesters with small amounts of one or more thickeners can also be used as lubricants. Blends containing up to 50% by volume of one or more water-insoluble polyoxyalkylene glycols, such as polyethylene or polypropylene glycols, or mixed oxyethylene/oxypropylene glycols, can then be used. The amount of overbased detergent added to the lubricating oil should be a small proportion, for example 0.01 to 10% by weight, preferably 0.1 to 5% by weight. The final lubricant may contain other additives depending on its specific application. For example, viscosity index improvers such as ethylene propylene copolymers may be present, as well as succinic acid-based dispersants, other metal-containing dispersant additives, and the well-known zinc dialkyldithiophosphate antiwear additive. can. The invention is illustrated by the following examples, but the invention is not limited thereto. EXAMPLE The following charges were placed in the reactor. Sulfonic acid 89.9 g Calcium oxide 5.2 g Anhydrous calcium chloride 1.9 g Toluene 115.9 g Oil (Solvent 150, neutral) 80.6 g Neutralized water and any other water present was removed azeotropically. The reaction mixture was then cooled to below 90° C. and 41.0 g of methanol, 50.6 g of calcium oxide, and various amounts of water as shown in Table 1 were added. The mixture was carbonated at 60° C. until an end point according to the following table was reached. The reaction mixture was slipped at a liquid temperature of 150° C. to remove volatile components, and 40.1 g of slipping oil was added.

[Table] *Almost solid at room temperature

Claims (1)

[Claims] 1 (i) (a) Oil-soluble alkylarylsulfonic acid or alkaline earth metal salt thereof having a molecular weight of 300 to 700 (b) Toluene, xylene or ethylbenzene as a solvent (c) C ₁ to _{C 5} Alcohol (d) Oil (e) A mixture of calcium oxide in excess of that required for the reaction with the sulfonic acid in a volume ratio of 30:70 of the above components (b) and (c).
~80:20, the weight of component (a) is 40-220% by weight of the total weight of oil in the mixture, and the weight of components (b) and (c) is each 30-160% by weight of the total weight of oil in the mixture. (ii) adjust the water content between 0.50 and 4% of the weight of excess calcium oxide; (iii) until the PH of the mixture is in the range 6.0 to 7.5 and the infrared spectrum is 872 cm ^- at a temperature below the boiling point of the lowest boiling component of the mixture until it first shows the formation of vaterite as indicated by peak ¹ .
A method for producing overbased calcium sulfonate, comprising the steps of (i) carbonating the mixture and (iv) removing volatile components.