JPH0735515B2 - Method for producing basic calcium sulfonate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a basic calcium sulfonate useful as an additive for lubricating oil, fuel oil or rust preventive oil. In the present invention, basic calcium sulfonate means a clear compound containing calcium in excess of stoichiometric amount as compared with the amount necessary to neutralize sulfonic acid,
Excess calcium is mainly present as calcium hydroxide. The total base number of the product (potentiometric titration method, JIS K 2
501) is 20 to 50 mgKOH / g, and the turbidity (product is white kerosene
15% by volume dissolved and measured with an integrating sphere turbidity measuring device) is 10
% Or less.

(Prior Art) Oil-soluble calcium sulfonate is known as an oil-soluble surfactant and is used in various industrial fields because of its excellent surface chemical properties such as solubilizing ability, dispersibility, adsorptivity and wettability. In particular, basic calcium sulfonate is used as a detergent-dispersant and rust preventive additive for lubricating oils for internal combustion engines. It acts to disperse harmful sedimentary substances such as precursors.
Further, those having a low base number are useful as rust preventive additives.

Conventionally, a general method for producing a basic calcium sulfonate is to pass carbon dioxide through a mixture of oil-soluble sulfonic acid or oil-soluble calcium sulfonate, calcium hydroxide or calcium oxide, a suitable solvent and a C _1-5 alkanol. It is known to be manufactured in.
The dispersion of basic calcium sulfonate in this process is calcium carbonate, a weak basic sulfonate.

Regarding the method for producing a dispersion of basic calcium sulfonate as calcium hydroxide, a method of heating an oil-soluble calcium sulfonate and an excess of a basic metal or its hydroxide or oxide in the presence of water, and a reaction accelerator There are known methods such as adding an alkylphenol, etc., but in all cases, the total base number was 30 mgKOH / g or less, or the clarity was low. It is considered that the reason why clear basic calcium sulfonate cannot be obtained is that the calcium hydroxide as a dispersion has a large particle diameter and cannot be retained in the sulfonate micelles, resulting in turbidity. Calcium hydroxide having a large particle size is inferior in acid neutralization ability.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing a basic calcium sulfonate having calcium hydroxide as a dispersion, having a clear, strong base number and excellent acid neutralization ability. is there.

(Means for Solving the Problems) A. (a) oil-soluble sulfonic acid or calcium salt thereof, (b) calcium hydroxide or calcium oxide in excess of stoichiometric amount that reacts with a, (c) Forming a mixture of mineral oil, (d) a hydrocarbon solvent, (e) a chloride of an alkali metal or an alcal earth metal, and (f) water, B. heating the mixture to remove water, and C. Highly transparent (turbidity 10% or less), which consists of obtaining a basic calcium sulfonate by separating it into a liquid containing insoluble matter and basic calcium sulfonate, and removing volatile substances from D. The present invention relates to a method for producing basic calcium sulfonate.

The dispersion of the basic calcium sulfonate in the present invention is calcium hydroxide, and since the strongly basic salt is dispersed in the sulfonate, it shows a strong base number when dissolved in a solvent for measuring a neutralization number. Therefore, the acid neutralizing action in the lubricating oil is quick and the acid neutralizing ability is more efficient. That is, according to the production method of the present invention, by adding chlorine ions in the presence of water and then dehydrating, it is possible to control the particle size of calcium hydroxide, which is a basic dispersion, to 0.02 μm or less. It is possible to obtain a basic calcium sulfonate having a high degree of acid neutralization ability.

The manufacturing process of the present invention includes 1) preparation and mixing of raw materials, and 2)
Removal of water by reflux or complete removal of water at the same time as the solvent, 3) removal of unreacted materials from the reaction mixture, 4) removal of volatile components from the basic calcium sulfonate-containing solution to obtain a final product. Be separated.

First, in the first step, oil-soluble sulfonic acid or its calcium salt, calcium hydroxide or calcium oxide, mineral oil,
A hydrocarbon solvent, a chloride of an alkali metal or an alkaline earth metal, and water are mixed, but the order of charging the respective raw materials need not be particularly careful. That is, the quality of the final product does not depend on the order of preparation.

The second step is the most important step in the present invention.
This is a step of removing water from the mixture, in which calcium hydroxide is trapped and stabilized in the micelle structure of sulfonate. About this dehydration process,
There are a method of removing only water during the azeotropic reflux of water and a solvent, and a method of simultaneously removing water and a solvent. In either method, a target product is obtained. In this step, the dehydration temperature and dehydration time are not particularly limited, but water needs to be removed by evaporation. In other words, the target product cannot be obtained by dehydration by a method such as centrifugation or adsorption.

The third step is often a problem in the method of making such dispersions containing inorganic salts such as calcium hydroxide or carbonate. That is, since this type of dispersion contains a large amount of finely divided inorganic salt, it is often difficult to pass it. If the amount is insufficient, the final product becomes cloudy and cannot be used as a lubricant additive. One way to measure the clarity of this type of product is to use white kerosene as a sample.
There is a method of dissolving 15% by volume and measuring with an integrating sphere type turbidity measuring device. When the turbidity measured by this method is 10% or less, it can be sufficiently used as a lubricating oil additive.

In the present invention, it is possible to remove unreacted substances by treating the reaction mixture obtained in the second step directly or after diluting it with a hydrocarbon solvent and treating it with a centrifuge (for example, 1500 G for 15 minutes). . In addition, a diatomaceous earth-based auxiliary agent or a perlite-based auxiliary agent which is usually used can also be used for rapid passing by a body feed or precoat method.

In the fourth step, volatile substances are removed and collected by vacuum distillation. The recovered hydrocarbon solvent can be used again for the purpose of the present invention.

The basic calcium sulfonate obtained by these steps is a reddish brown transparent substance and has a viscosity that does not hinder handling. Common basic calcium sulfonate is highly viscous and often causes inconvenience in handling. For this reason, an additive of some kind is often added in order to reduce the viscosity, which causes a decrease in the flash point of the product, which is a safety issue. According to the method of the present invention, such a viscosity reducing means is unnecessary, and there is no need to add a new mixing step, which is safe and economical.

(Effect of the invention) The dispersion of the basic calcium sulfonate in the present invention is calcium hydroxide, and since the strongly basic salt is dispersed in the sulfonate, it has a strong base number when dissolved in a solvent for measuring the neutralization number. Indicates. Therefore, the acid neutralizing action in the lubricating oil is quick and the acid neutralizing ability is more efficient. Further, the basic calcium sulfonate of the present invention has a feature of high clarity.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 In a three-liter four-necked flask equipped with a reflux decanter, a reflux condenser, a thermometer, and a stirrer, 500 g of oil-soluble calcium sulfonate (mineral oil content 38%), 26 g of calcium hydroxide,
440 g of benzene, 5.1 g of calcium chloride dihydrate and 85 g of water were added and mixed by a stirrer. This mixture is heated to 74
The mixture was refluxed at ~ 84 ° C, and only water was removed with a reflux decanter during reflux, and benzene was returned to the reaction system. The amount of water in the system is 1.0
After performing the above operation until it becomes less than or equal to%, let it cool down,
Pressure was applied using a super-assisting agent. The liquid was heated under reduced pressure to remove volatile substances, and 434 g of clear basic calcium sulfonate was obtained. The total base number was 43.4 mg KOH / g.

Example 2 1 liter 4 equipped with atmospheric distillation, thermometer and stirrer
Oil-soluble calcium sulfonate (mineral oil content)
55%) 280 g, calcium hydroxide 10 g, toluene 140 g, calcium chloride dihydrate 2.0 g, and water 12.5 g were added and mixed by a stirrer. The mixture was heated to 140 ° C. to almost completely evaporate water and toluene. After allowing to cool, 300 g of toluene was added to the reaction mixture, and the solution dissolved in toluene by stirring was centrifuged (1500 G, 15 minutes). The resulting supernatant was heated under reduced pressure to remove volatile substances and 260 g of clear basic calcium sulfonate was obtained.
The total base number was 33.9 mg KOH / g.

Example 3 257 g of a clear basic calcium sulfonate was prepared in the same manner as in Example 2 except that 2.0 g of sodium chloride was used instead of calcium chloride, and the same equipment, raw materials and charging amount were used. Got The total base number was 28.5 mg KOH / g.

Example 4 The procedure was the same as in Example 2 except that 2.0 g of barium chloride dihydrate was used instead of calcium chloride, and the same procedure as in Example 2 was used. 264 g of calcium sulfonate was obtained. Total base number is 28.1mgKOH /
It was g.

Comparative Example 1 The same apparatus and raw materials as in Example 2 were used and mixed in the same amount with a stirrer, and then heated and refluxed while stirring without removing water. After allowing the reaction mixture to cool, it was transferred to a separating funnel and the toluene layer was separated. The obtained toluene solution was centrifuged (1500 G, 15 minutes), and the supernatant was heated under reduced pressure to remove volatile substances. The total base number of the obtained sulfonate was 5.2 mg KOH / g.

The contents of Examples and Comparative Order are summarized in Table 1.

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Claims (1)

[Claims] 1. A. (a) Oil-soluble sulfonic acid or calcium salt thereof, (b) Calcium hydroxide or calcium oxide in excess of stoichiometric amount that reacts with a, (c) mineral oil, (d) hydrocarbon Form a mixture of system solvent, (e) chloride of alkali metal or alcal earth metal, and (f) water. B. Heat the mixture to remove water, C. Insoluble matter and basic calcium due to excess A method for producing a basic calcium sulfonate having a high transparency (turbidity of 10% or less), which comprises obtaining a basic calcium sulfonate by separating a liquid containing a sulfonate and removing a volatile substance from the liquid D.