JPH0737625B2 - Method for producing highly basic calcium sulfonate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a highly basic calcium sulfonate useful as an additive for a lubricating oil, a fuel oil or a metalworking oil. In the present invention, basic calcium sulfonate means a clear compound which contains calcium in excess of stoichiometric amount compared to the amount required to neutralize sulfonic acid.

(Prior Art) Conventionally, as a method for producing a highly basic calcium sulfonate, an oil-soluble sulfonic acid or an alkaline earth metal sulfonate is used, and an aromatic or aliphatic hydrocarbon solvent, methanol, an oxide of calcium, or water. It is common and basically known to blow carbon dioxide gas into a mixed solution of oxides to generate calcium carbonate to make it highly basic.

However, when carbonation is performed using calcium hydroxide, in addition to calcium carbonate, the water that is stoichiometrically produced as a by-product corresponding to the carbonation rate is used to recover the highly basic calcium sulfonate of the desired properties. This complicates the manufacturing process, especially the solvent recovery process and the over-process. That is, in the solvent recovery step, the coexistence of water in the two components of the aromatic or aliphatic hydrocarbon solvent and methanol complicates single separation and recovery of each component. Further, in the overstep, the coexistence of excessive water causes coarsening of the calcium carbonate particles and a marked increase in the viscosity of the reaction mixture to reduce the overcapacity, and generally, a clear overbased calcium sulfonate cannot be obtained.

In the method for producing a highly basic calcium sulfonate that has been already proposed in the past, it has been explained that the volatile substance is removed by heating after the carbonation reaction, but the treatment method thereof, in particular, the removal and reduction of water by-produced by the reaction There are few examples of inventions that describe the method in detail. For example, the following method has been disclosed as a method for obtaining a clear and highly basic high-basic calcium sulfonate.

1. an oil-soluble sulfonic acid or its salt in a hydrocarbon solvent,
After introducing a carbon dioxide gas in a reaction mixture containing methanol and calcium oxide or calcium hydroxide in an amount less than the stoichiometric amount required to convert the contained calcium oxide or calcium hydroxide into calcium carbonate, the volatile substance is removed. A method of obtaining a highly basic calcium sulfonate by removing carbon dioxide by heating and introducing carbon dioxide again (Japanese Patent Publication No.
58-29360 publication).

2. Introduce less than stoichiometric amount of carbon dioxide into a reaction mixture containing oil-soluble sulfonic acid or its salt, lower alcohol, calcium hydroxide and water in aromatic hydrocarbon solvent, and after heating , Method of introducing carbon dioxide again. A method for obtaining a highly basic calcium sulfonate characterized by using two-step carbonation and water in combination (see JP-A-57-118551). However, since these methods do not mention in detail how to remove and reduce the water produced as a by-product, they can be used as they are as a production method for producing a high-quality, highly basic calcium sulfonate economically on an industrial production scale. Difficult to do.

(Problems to be Solved by the Invention) An object of the present invention is to easily separate a hydrocarbon-dissolved part of a reaction product mixture from an insoluble matter mainly from an inorganic substance, and also to allow a reaction to be rapid and calcium content to be high. It is an object of the present invention to provide a method for producing a highly basic calcium sulfonate that is high, sufficiently clear and has a high total base number.

Another object of the present invention is to provide a method for producing a highly basic calcium sulfonate, which involves a simple and effective use of the recovered solvent.

The present inventors, as a result of earnest research to achieve the above objects,
Regarding the reaction product mixture after completion of the carbonation reaction, a) heat and distill off by-produced water, methanol and a part of aromatic or aliphatic hydrocarbon solvent from the reaction product mixture under normal pressure or constant reduced pressure conditions. B) By adding 1 to 1.5 times the stoichiometrically equivalent amount of calcium oxide to the by-produced mixed solvent to the above-distilled mixed solvent, and then performing strong stirring and mixing operations, c ) The by-product water in the mixed solvent is absorbed by calcium oxide, and at the same time, the calcium oxide is mostly converted into a fine calcium hydroxide in a stoichiometrically almost equivalent amount by a chemical reaction, and d ) The mixed solvent after the above treatment for suspending the obtained calcium hydroxide and calcium oxide is effectively recovered and used as a part of the raw material in the next step of producing the overbased calcium sulfonate. It was investigated that the purpose of is achieved.

(Means for Solving the Problems) The present invention provides (a) an oil-soluble sulfonic acid or an alkaline earth metal sulfonate (b) an aromatic or aliphatic hydrocarbon solvent (c) methanol (d) a mineral oil, and (E) for a mixture of calcium hydroxide in excess of the stoichiometrically required amount as compared to the amount required to neutralize the sulfonic acid present, (f) 75-based on the above calcium hydroxide. Carbonate using 95 wt% carbon dioxide as a raw material, and then remove by-product water by absorbing it with calcium oxide,
Calcium oxide changes to calcium hydroxide by moisture absorption, and a mixed solvent that suspends calcium hydroxide and calcium oxide is used as a part of the raw material in the next highly basic calcium sulfonate manufacturing process. The present invention relates to a method for producing a highly basic calcium sulfonate, which is characterized by removal of water and simple and effective use of a recovered solvent after the reaction.

INDUSTRIAL APPLICABILITY The present invention is intended to remove water by-produced in a highly basic calcium sulfonate manufacturing process by a hygroscopic effect of calcium oxide, and to apply calcium hydroxide generated by the moisture absorption to a raw material and to simultaneously simplify a solvent recovery process. Regarding the characteristic manufacturing method, it is not mentioned in the above-mentioned manufacturing method disclosed heretofore, or it is essentially different in terms of the manufacturing process.

In the present invention, known oil-soluble sulfonic acids, alkaline earth metals (eg, calcium, barium, magnesium, etc.) and sulfonates can be used.

Hydrocarbon solvent, when supplying carbon dioxide into the mixture,
Since it is for keeping the mixture in a fluid state, it is used in an amount sufficient to keep the mixture in a fluid state. Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene and the like, and examples of the aliphatic hydrocarbon solvent include petroleum naphtha, hexane, heptane and the like.

Commercially available industrial methanol is sufficient for methanol,
If the water content is within the standard value, no purification treatment such as dehydration is required. The use of lower alcohols having 2 to 5 carbon atoms other than methanol cannot be used in the process of the present invention. This is because calcium carbonate is not produced in lower alcohols other than methanol, or even if it is produced, its crystal form is a calcite type, and the above object cannot be achieved. The amount of methanol used is preferably 0.5 to 1.5 parts by volume with respect to 1 part by weight of calcium hydroxide.

Commercially available, inexpensive industrial slaked lime is sufficient for calcium hydroxide. The preferred range of the amount used varies depending on the desired degree of basicity, but is preferably 30% by weight or more based on the oil-soluble calcium sulfonate in order to obtain high basicity. When an oil-soluble sulfonic acid is used as a raw material, the stoichiometric amount necessary for neutralizing the sulfonic acid is used in addition to the above amount.

As the calcium oxide used in the above manufacturing process, commercially available inexpensive industrial quicklime is sufficient. The preferred range of the amount of use varies depending on the desired degree of basicity and the amount of water in the mixed solvent distilled off by the operation of a) above, but the amount of water is 1.0
The equivalent or more and 1.5 equivalents or less are preferable in order to obtain a stable quality high basic calcium sulfonate.

On the other hand, in order to efficiently perform the treatments of b) and c), the stirring and mixing machine used should generate a strong shearing force at a high speed such as a batch-type or line-mounted homomixer or homogenizer. Therefore, a device that can be expected to have efficient mixing and dispersing effects is preferable. The reason is that the contact area between calcium oxide and water is increased by improving the state of dispersion of calcium oxide in the mixed solvent in the liquid, and the reaction rate is improved. Also, the processing temperature,
Regarding the treatment time, the higher the temperature and the longer the time, the more effective it is. However, considering the water concentration in the reaction solution before the start of the next carbonation reaction, it is considered that 30 ° C or more and 60 ° C or less, 30 minutes or more and 120 minutes or less .

Equipment such as a homomixer and a homogenizer are used not only for the purpose of the above-mentioned treatment but also for circulating or batch-mixing the reaction solution before and after the carbonation reaction and during the carbonation reaction in the highly basic calcium sulfonate manufacturing step. It was proved that the carbonation reaction also has the effect of improving the reaction rate when used for. This is because, similarly to the above reason, improving the dispersion state of the powder raw material in the reaction liquid leads to efficient carbonation.

A flow diagram of the operations and processes of a), b), c), and d) above is shown in FIG. Before and after the carbonation reaction and during the carbonation reaction, the reaction solution was mixed with a propeller in a reaction tank at the same time as a batch type or line-mounted homomixer,
Homogenizer mixing (line installation, circulation type homogenizer mixing in the figure) is performed, and an efficient carbonation reaction is performed. At this time, it is preferable to introduce carbon dioxide while keeping the reaction temperature constant at 30 to 50 ° C.

After the reaction, water, methanol and a part of the aromatic or aliphatic hydrocarbon solvent produced as a by-product from the reaction solution are heated and distilled off from the reaction product mixture under normal pressure or constant reduced pressure conditions. When toluene is used as the solvent, the reaction temperature is
It is preferable to heat up and heat up to 130 ° C. The reason is to efficiently recover the highly basic calcium sulfonate in a high yield in the subsequent overstep.

Next, the mixed solvent that has been heated and distilled off is cooled and condensed in a cooler, and a stoichiometrically equivalent to 1.5 times equivalent amount of calcium oxide is added to the water by-produced in the moisture absorption treatment tank. After that, strong stirring and mixing are carried out for 30 minutes to 120 minutes under the temperature condition of 30 ° C to 60 ° C using a homogenizer. By this operation, the moisture absorption effect of calcium oxide is accelerated, and it is changed into fine calcium hydroxide almost stoichiometrically and quickly. Further, the calcium hydroxide produced at this time is returned to the reaction tank together with the solvent and can be effectively used as a part of the raw material for the next carbonation reaction.

The series of operations of the present invention facilitates the recovery of the solvent after the carbonation reaction. Generally, after the carbonation reaction and before the overstep,
In order to obtain a sufficiently clear highly basic calcium sulfonate, a step of distilling off volatile substances containing most of water and methanol by-produced in the reaction and separating and collecting each component is taken. In that case, the hydrocarbon-based solvent used at the same time is often azeotropically distilled, and the distillate becomes a three-component mixed solvent, and a complicated solvent recovery device is required for separation and recovery of each component. In this respect, the present invention has a feature that the mixed solvent containing most of water and methanol immediately after the reaction does not need to be separated and recovered for each component, and the process and the equipment can be relatively simple.

The overbased calcium sulfonate produced by the method of the present invention is a solution of calcium sulfonate in mineral oil, which itself acts as a surfactant for dispersing an excess of colloidal alkaline earth metal compound. The acid or sulfonate should be soluble in mineral oil. Examples of the oil-soluble calcium sulfonate include oil-soluble petroleum sulfonic acid, alkyl sulfonic acid,
Examples thereof include calcium salts of arylsulfonic acids and alkylarylsulfonic acids.

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

In the Examples and Comparative Examples, unless otherwise stated, the reaction mixtures consisting of the following ratios of reactants were in a laboratory scale test of 3, and consisted of:

Toluene 1000 ml Methanol 250 ml Calcium sulfonate ¹⁾ 1000 g Calcium hydroxide ²⁾ 330 g Note 1) Oil solution containing 37.5% by weight of the active portion of calcium sulfonate having an average molecular weight of 1030 (diluted and adjusted with mineral oil).

Note 2) Commercial industrial slaked lime containing about 0.4% by weight of magnesium.

However, in Examples 3 to 4, a calcium hydroxide dispersion liquid was used, which was produced by subjecting a mixed solvent obtained by heating and distilling water, methanol and a part of a hydrocarbon solvent to moisture absorption treatment with calcium oxide.

Example 1 A reactor equipped with a propeller-type stirrer was charged with calcium sulfonate whose components were previously adjusted with mineral oil, methanol, toluene and calcium hydroxide, and heated so that the reaction mixture was kept at 40 ± 1 ° C., The introduction of carbon dioxide gas was started while controlling the temperature by cooling. Carbon dioxide was introduced at a rate of 87/110 minutes.

After completion of the introduction, the reaction mixture was heated to 130 ° C., and water, by-product of the carbonation reaction, methanol, and a part of toluene were added in total.
0 g was distilled off. After cooling to room temperature, radio light #
A 900 pre-coated reactor was used to pass the reaction mixture, previously diluted with 580 g of toluene and then body fed with Dicalite # 419, at a pressure of 1.5 kg / cm ² .

The liquid was heated to 130 ° C. under reduced pressure to remove volatile substances. The residual liquid was a clear highly basic calcium sulfonate mineral oil solution (hereinafter simply referred to as the highly basic calcium sulfonate), and its properties are shown in Table 1.

Example 2 The same operation as in Example 1 was performed until the raw materials were charged.
However, the scale of the experiment was 20 times as large as that of the laboratory scale, because carbon dioxide was introduced while circulating and mixing the reaction mixture through a line-mounted homogenizer.

Other operations during and after the introduction of carbon dioxide were exactly the same as in Example 1. The properties of the obtained overbased calcium sulfonate are shown in Table 1.

Example 3 For the raw materials methanol, toluene and calcium hydroxide, the following treatment liquids were used.

That is, the experiment of Example 1 was preliminarily performed at 20 times the laboratory scale,
After the introduction of carbon dioxide gas, the reaction mixture was heated to 130 ° C. and distilled off, and a mixed solution consisting of water, methanol and a part of toluene by-produced by the carbonation reaction, about 11.6 kg, was brought to room temperature through a line-mounted homogenizer. While keeping the temperature, calcium oxide was added to circulate and mix to absorb moisture.
The moisture absorption treatment time was 90 minutes, and the amount of calcium oxide added was 1.2 times equivalent to the amount of water.

After the above treatment, 1600 g of the uniformly dispersed treatment liquid was used in place of the methanol, toluene and calcium hydroxide of Example 1, calcium sulfonate was then added, and the same operation as in Example 1 was carried out to carry out highly basic calcium. A sulfonate was obtained. The properties are as shown in Table 1.

Example 4 As for the raw materials methanol, toluene and calcium hydroxide, 800 g of the same treatment liquid as in Example 3 was used in part.
To the rest, 100 ml of methanol, 400 ml of toluene, 171 g of calcium hydroxide and calcium sulfonate were added, and the same operation as in Example 1 was carried out to obtain a highly basic calcium sulfonate. The properties are as shown in Table 1.

Comparative Example 1 Carbon dioxide gas was introduced in the same manner as in Example 1 except that 250 g of calcium oxide was used instead of 330 g of calcium hydroxide of Example 1, but carbon dioxide gas was hardly absorbed by the reaction mixture. The carbonation reaction did not proceed at all.

Comparative Example 2 Carbon dioxide gas was introduced in the same manner as in Example 1 by using 171 g of calcium hydroxide and 120 g of calcium oxide instead of 330 g of calcium hydroxide of Example 1, but after introducing carbon dioxide, about 55 No longer absorbs into the reaction mixture after
The reaction mixture began to turn cloudy.

Next, the same raw materials were charged again, carbon dioxide was introduced in the same manner as in Example 1, and the reaction was stopped when 50 carbon dioxide was introduced. After the introduction, the reaction mixture was treated in the same manner as in Example 1 to obtain a highly basic calcium sulfonate. The properties are as shown in Table 1, and compared with Examples 1 to 4, the transient properties were slightly poor.

From the above, when calcium oxide was used as a raw material during the carbonation reaction from the beginning, absorption of carbon dioxide gas was hardly seen and the reaction did not proceed. Also, when calcium oxide is partially used as a raw material instead of calcium hydroxide, it is difficult to obtain a highly basic calcium sulfonate having a desired base number due to partial carbonation. This fact means that it is impossible to avoid the by-product of water when carbonating using calcium oxide as a raw material.

(Effect of the invention) In industrial production of highly basic calcium sulfonate, recovery and use of a solvent are indispensable conditions in view of economy, but by-product of water makes recovery of solvent technically difficult. . The present invention solves this difficulty and at the same time
It was confirmed that the treatment liquid can be used as a raw material for the next production.

Table 2 shows a comparison of performance of the products obtained in Examples 1, 3, and 4. The highly basic calcium sulfonate produced by the method of the present invention is evaluated as a highly basic calcium sulfonate production method that is sufficiently applicable to industrial production without inferior in product properties and performance even when compared with conventional methods. be able to.

Sample oil: 5 wt% of sample sulfonate dissolved in neutral oil.

Oil amount: 200ml Panel temperature: 280 ℃ Oil temperature: 100 ℃ Test time: 4 hours Splashing: Continuous splashing

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C10M 125: 10 125: 00) C10N 10:04 30:04 40:25 70:00 (56) References 59-139354 (JP, A) JP-A-56-43258 (JP, A)

Claims (1)

[Claims] 1. An oil-soluble sulfonic acid or an alkaline earth metal sulfonate (a) an aromatic or aliphatic hydrocarbon solvent (c) methanol (d) mineral oil, and (e) a sulfonic acid present. (F) 75 to 95% by weight of carbon dioxide gas based on the above-mentioned calcium hydroxide is added to a mixture of calcium hydroxide in excess of the stoichiometric amount compared to the amount required to neutralize Carbonated by using it as a raw material, and then removing byproduct moisture by absorbing it with calcium oxide,
Calcium oxide changes to calcium hydroxide by moisture absorption, and a mixed solvent that suspends calcium hydroxide and calcium oxide is used as a part of the raw material in the next highly basic calcium sulfonate manufacturing process. And a method for producing a highly basic calcium sulfonate characterized by simple and effective use of a solvent recovered after the reaction.