JPH034599B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for producing highly basic calcium sulfonates. Such highly basic sulfonate salts are useful as additives in lubricating oils. The term highly basic calcium sulfonate refers to a calcium salt of a sulfonic acid that contains a stoichiometric excess of calcium over the amount required to neutralize the sulfonic acid. Often this excess calcium is present in the form of colloidal calcium carbonate suspended in calcium salts of sulfonic acids. These highly basic calcium sulfonates are particularly useful as additives in lubricating oils, particularly automotive lubricating oils, where their highly basic nature neutralizes acids produced during engine operation. Additionally, the dispersing effect of the calcium sulfonate keeps particulate matter suspended in the oil, thereby preventing the formation of harmful deposits in the oil. Preparing a highly basic calcium sulfonate by carbonating a mixture of an alkylaryl sulfonic acid, calcium oxide or hydroxide, a hydrocarbon solvent (or solvent mixture), a reaction promoter and optionally water. is well known.
Typical solvents are aromatic compounds such as toluene or xylene, or aliphatic compounds such as hexane. The requirements for a highly basic calcium sulfonate to be used as a lubricant additive are that it must combine oil solubility, high basicity, and low viscosity. The modern trend of replacing naphthenic mineral oils with paraffinic oils has resulted in increasingly difficult oil solubility, resulting in undesirably hazy lubricants. The economic requirement of this process is that the mixture must be filtered as soon as possible when the reaction is complete. It is an object of the present invention to provide an economical process for the production of highly basic calcium sulfonates with acceptable solubility even in relatively highly paraffinic mineral oils. Therefore, the present invention provides carbonation of a mixture of (i) sulfonic acid (ii) calcium hydroxide (iii) hydrocarbon solvent (iv) _C1 - _C3 alcohol (v) water, wherein the carbonation is
The stoichiometric excess of calcium hydroxide over that required to react with the sulfonic acid and carbon dioxide is (a) carbonated until the mixture is substantially saturated. (b) by intermittent chlorination followed by addition of further calcium hydroxide (ii); or (b) by incorporating all the calcium hydroxide (ii) in the initial mixture;
This is provided by stopping the carbonation before the reaction of (ii) is complete, and the amount of water (v) to be included is between 8 and 25% by weight based on the total weight of calcium hydroxide (ii). , followed by addition of a mineral oil diluent and removal of volatiles by distillation.
A method for producing highly basic calcium sulfonates having a total base number in the range of 320 mg KOH/g is provided. The weight of water (v) above does not include water generated during the process. The sulfonic acids that can be used in the reaction mixture include oil-soluble sulfonic acids, which are natural or synthetic sulfonic acids such as mahogany or petroleum alkyl sulfonic acids; alkyl sulfonic acids; or alkaryl sulfonic acids. .
The alkyl sulfonic acid should preferably contain a minimum of 25 carbon atoms per molecule, and the alkaryl sulfonic acid (e.g. alkylbenzene sulfonic acid) preferably has a minimum of 18 carbon atoms in its alkyl chain. Should. The most preferred sulfonic acids are those with a molecular weight of 300-700, such as 400-500. Preferably, the sulfonic acid is used as a solution in mineral oil, preferably consisting of 50-90%, more preferably 60-80% by weight of sulfonic acid. The hydrocarbon solvent may be an aromatic or aliphatic hydrocarbon. Aromatic hydrocarbons are preferred, examples of which are toluene, chirecine and ethylbenzene. Suitable aliphatic hydrocarbons include n-hexane, n-heptane, n-decane, n-dodecane,
Included are paraffinic hydrocarbons such as white spirit, naphtha, or isoparaffins and cyclic paraffins such as cyclohexane. The _C1 - _C3 alcohol used is preferably methanol. This is because using other alcohols tends to result in gel formation during carbonation. No. 3,830,739 teaches the use of excess calcium hydroxide in the production of highly basic calcium sulfonates. However, when there is water added in the reaction mixture, i.e. if the water is between 4 and 35% by weight, preferably between 6 and 35% by weight relative to the weight of calcium hydroxide in the reaction mixture. It has been found that preferably 8-25% by weight, most preferably 15-25% by weight allows for faster filtration. This amount of water generally corresponds to about 2.5 to 5%, preferably 3 to 4%, by weight of the total mixture. It has been found that the presence of this amount of water makes it possible to obtain a product with acceptable solubility in a strong paraffinic substrate. These oils are generally the October/November 1958 edition of Erdo Ale. Und. 50% as determined by infrared spectroscopy according to the method of Gunther Brandes, described in Erdol unt kohle.
Contains the above paraffinic carbon atoms. especially,
According to the present invention, the viscosity at 100〓 (37.78℃) is
A product is obtained which is soluble in paraffinic oils of equal to or greater than 500 sus. The product also has improved filterability. The exact amount of water to be used depends on the amount of excess calcium hydroxide used and the purity of that calcium hydroxide. It has been discovered that the use of a stoichiometric excess of calcium hydroxide provides a product with improved oil solubility, particularly in paraffinic mineral oils. By stoichiometric excess is meant in excess of the amount needed to react the sulfonic acid and the carbon dioxide. This oil solubility improvement introduces excess calcium hydroxide into the mixture,
Either the carbonation is controlled so that some unreacted calcium hydroxide remains, or the mixture is carbonated until carbon dioxide uptake is complete and then excess calcium hydroxide is added before filtering. It has also been discovered that this can be achieved by It can also be seen that the product must be alkaline to the phenolphthalein in order to improve its oil solubility. 5 to 50% by weight, preferably 10 to 20% by weight of the total weight of calcium hydroxide used
It is desirable that the excess constitutes the excess. The filtration rate of the product and its solubility in highly paraffinic oils depend on the amount of water added and the quality of calcium hydroxide, with calcium carbonate as an impurity of not more than 3% by weight, preferably not more than 1% by weight. It has been found that the use of calcium hydroxide, which does not contain calcium hydroxide, is desirable. The mixture is an oil solution of its components; suitable oils include hydrocarbon oils, especially those of mineral origin. Viscosity at 100〓 (37.78℃) is 15~
Oil such as 30CS is extremely suitable.
Alternatively, other oils that may be used are the lubricating oils discussed later herein. The relative proportions of each substance in this reaction mixture are not critical, but for every 350 parts by weight of sulfonic acid,
350, preferably 250-300 parts of alcohol, 300-300
800, preferably 400 to 600 parts of hydrocarbon solvent and 180
Preferably used with ~210 parts by weight of calcium hydroxide. The reaction mixture is at a temperature of 20-35°C, preferably 20-30°C during carbonation. This is because it has been observed that using higher temperatures, for example 50°C, the product tends to become greasy, while using lower temperatures, for example 10°C, the product tends to become milky. If carbonation is continued to saturation point and excess calcium hydroxide is added later, 95~
For each case in which 115 parts by weight of carbon dioxide are in the mixture
It can be seen that every 350 parts by weight of sulfonic acid is absorbed. Once carbonation is complete and some excess calcium hydroxide has been added, the mixture may be subjected to a steeping period before being filtered. This is because it has been found that the filtration rate of the mixture is significantly increased in this way. The mixture may be kept at 20-35°C, preferably 25-35°C for at least 1/2 hour.
The product can be held at this temperature for an extended period of time, but for economic reasons it is preferred to do so for about 1 hour. As another variant, diluent oil can also be added to the mixture before the soaking step. The mixture is then heated to remove volatiles, ie, hydrocarbon solvents and _C1 - _C3 alcohols, and then filtered, typically using a filter aid, to yield the highly basic calcium sulfonate as a filtrate. The overbased calcium sulfonate detergent produced by the method of the invention is suitable for use as an additive to mineral and synthetic lubricating oils. The lubricating oil may be any animal, vegetable or mineral oil, for example from naphtha to spindle oil,
Petroleum fractions up to lubricating oil grade of SAE 30, 40 or 50,
Castor oil, fish oil or oxidized mineral oil. especially,
The product is useful in paraffinic mineral oils, as mentioned above, in which known calcium sulfonates have limited solubility. Suitable synthetic ester lubricants include dioctyl adipate, dioctyl sebacate, didecyl azelate, tridecyl adipate, didecyl
Diesters such as succinate, didecyl glutarate, and mixtures thereof are included.
Alternatively, synthetic esters are prepared by reacting polyhydric alcohols such as trimethylolpropane and pentaerythritol with monocarboxylic acids such as butyric acid, caproic acid, caprylic acid, and pelargonic acid to form the corresponding tri- and tetraesters. Polyester like this is fine. Esters can also be used as base stocks, such as those produced by esterification reactions between dicarboxylic acids, glycols and alcohols and/or monocarboxylic acids. Other additives may also be included in the lubricating oil along with the additives produced by the method of the present invention. The choice of additive will depend on the application for which the lubricating oil is to be oiled. Examples of suitable additives include alkyl succinimide dispersants, copolymerizable viscosity index improvers, and zinc dialkyldithiophosphate antiperspirant additives. The invention is illustrated by, but in no way limited to, the following examples. In these examples the filtration rate was set in the Buchna funnel for 1 hour or until 500 g of filtrate was obtained.
Whichever is faster was measured. A 77 square centimeter area of filter paper was used at 150° C. and 7 g of filter aid Clarcel® DCB was layered onto the filter paper. Example 1 52 parts by weight of alkylarylsulfonic acid and 90 parts by weight of toluene were mixed in a reaction vessel to completely dissolve the sulfonic acid. 41 parts of methanol and 6.7 parts of water were added, the mixture was stirred, and 28.5 parts of calcium hydroxide (95% pure and containing 3% by weight of calcium carbonate as an impurity) was added, while approx.
It was kept at 25℃. Carbon dioxide was then passed through the reaction mixture at a rate of 4.2 parts/hour until no more carbon dioxide was absorbed, which took about 4 hours. The temperature was kept in the range 25-30°C during the introduction of carbon dioxide. After carbonation was complete, a further 6 parts of calcium hydroxide were introduced and the mixture was stirred for 1 hour at about 30°C.
46 parts of paraffinic mineral oil were then added and the mixture was heated to remove the volatiles, i.e. the toluene/water azeotrope which distilled off at about 105°C, and the remaining toluene was removed by blowing nitrogen at 150°C. . Finally 7.5 parts of filter aid Clacel®
Add DCB and filter the product as described above,
Total base number (TBN) within the range of ~320mgKOH/g
A filtrate was obtained. Various preparations (some comparative) have been carried out according to the basic method described above, but in some cases the carbonation is stopped before absorption is complete, and in other cases the carbonation is stopped. The amount of calcium hydroxide added after salination and the amount of water included in the reaction mixture were varied. In each, the product has a TBN of approximately 300 and its filterability, appearance and
60 with a viscosity of 600sus at 100〓(37.78℃)
The solubility in highly paraffinic mineral oil containing % paraffinic carbon atoms was as follows.

【table】

Table: In all cases where water was included, the products had acceptable viscosities. Solubility is determined by adding 5 g of filtrate to 95 g of oil and visually observing the solubility at room temperature. - are comparative examples, and and are examples of the present invention. was used as a reference example from a practical standpoint.
Although the product was hazy and hazy, it provided high filterability. However, it has the drawback of giving a kinematic viscosity of 82 centistokes at 100°C. (In contrast, the products of and are 59 and 61, respectively)
It was centistokes. ) Example 2 The method of Example 1 was repeated using a different source of calcium hydroxide with a purity of 98% and containing less than 1% by weight of calcium carbonate. In this example, all the calcium hydroxide was included in the initial reaction mixture, and the carbonation was such that 82% of the stoichiometric amount of carbon dioxide needed to react with all free calcium hydroxide It was stopped when absorbed into the reaction mixture. Various amounts of water were added and the properties of the resulting product were as follows:

[Table] Moya Moya
13.0 270 Transparent Haze Haze
Moya Moya In this example, 15g of filter aid was added before filtration.
Every 500 g of sulfonic acid was added. Oil 1 is the paraffinic oil used in Example 1, while Oil 2 contains 70 parts of the oil of Example 1 and 30 parts of 60% paraffinic carbon atoms.
It was a blend with paraffin oil having a viscosity of 2500sus at 100㎓ (37.78℃). is a comparative example, and ~ is an example of the present invention. and gave high filterability to Oil 1.2, although it may cause haze.

Claims (1)

[Claims] 1. A process for producing highly basic calcium sulfonate having a total base number in the range of 300 to 320 mgKOH/g, comprising: (i) sulfonic acid (ii) calcium hydroxide (iii) a hydrocarbon solvent (iv) C ₁ -C ₃ alcohol (v) Carbonate the mixture of water, with the carbonation being reduced to 20
The stoichiometric excess of calcium hydroxide over that required to react with the sulfonic acid and carbon dioxide is (a) carbonated until the mixture is substantially saturated. (b) by intermittent chlorination followed by addition of further calcium hydroxide (ii); or (b) by incorporating all the calcium hydroxide (ii) in the initial mixture;
The amount of water (v) to be included is between 8 and 25% by weight based on the total weight of calcium hydroxide (ii), provided by stopping the carbonation before the reaction of (ii) has finished. , followed by adding a mineral oil diluent and removing the volatile substances by distillation. 2. A method according to claim 1, wherein an excess of calcium hydroxide is used in an amount of 5 to 50% by weight. 3. Process according to claim 1 or 2, in which the reaction mixture is maintained at a temperature in the range from 20 to 35° C. subsequent to carbonation until filtered. 4. Claim 1, wherein the calcium hydroxide contains only 1% by weight or less of calcium carbonate.
The method according to any one of items 1 to 3.