JP2606737B2 - Method for producing alkylphenols - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an alkylphenol, and more particularly, to a rearrangement reaction, a disproportionation reaction or a reaction product obtained after a reaction between a phenol and an olefin. The present invention relates to a method for efficiently producing an alkylphenol useful as a raw material for various chemical products without causing a side reaction such as an isomerization reaction.

[Prior art] Alkyl phenols are used as raw materials for various chemicals. Among them, for example, 2,6-di-t-butylphenol is a phenol resin, a surfactant, an ultraviolet absorber, an intermediate of an oil-soluble dye, and a lubricating oil. It is a compound useful as a raw material for agents and additives for resins.

Heretofore, as a method for producing such alkylphenols, there has been known a method of reacting phenols with olefins in the presence of aluminum triphenoxide as a catalyst (Japanese Patent Publication No. 33535/1973).

In order to separate the spent catalyst and the target product from the reaction product, filtration is usually employed.
Because the reaction product is very difficult to filter,
A method of treating the reaction product with a mineral acid (hydrolysis treatment) to separate it into an organic phase and an aqueous phase, and then distilling the organic phase to obtain alkylphenols, while recovering the aluminum component from the aqueous phase. (See page 6, lines 5 to 14 of JP-A-55-133324).

However, the method of treating the reaction product with sulfuric acid has the disadvantage that in the catalytic decomposition step, the rearrangement, disproportionation or isomerization reaction of the target alkylphenols is caused, and the yield of alkylphenols as a final product is reduced. was there.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the above-mentioned disadvantages in the prior art and to efficiently process a reaction product without causing a rearrangement, disproportionation or isomerization reaction. To provide a method for producing an alkylphenol with improved yield.

[Means for Solving the Problems] The present invention for achieving the above object provides a method for producing an alkylphenol in which a phenol is reacted with an olefin in the presence of aluminum triphenoxide to obtain a reaction product. This is a method for producing alkylphenols, which comprises performing a multi-stage filtration after adding a solvent.

A. Reaction between phenols and olefins -reaction raw material- Examples of phenols used in the present invention include:
The following general formula (However, R ¹ and R ² each represent a hydrogen atom or an alkyl group. R ¹ and R ² may be the same or different from each other.) it can.

Specific examples of the compound represented by the general formula include, for example, phenol, methylphenol, ethylphenol, propylphenol, isopropylphenol, butylphenol, isobutylphenol, tert-butylphenol, amylphenol, isoamylphenol, tert-amylphenol, Hexylphenol, isohexylphenol, tert-hexylphenol, heptylphenol, octylphenol, nonylphenol, dimethylphenol, diethylphenol, diisopropylphenol, di-tert-butylphenol,
And di-tert-amylphenol.

Among these, for example, phenol, cresol, 2-ethylphenol, 2-propylphenol,
2-isopropylphenol, 2-butylphenol,
2-isobutylphenol, 2-tert-butylphenol, 2-amylphenol, 2-isoamylphenol, 2-tert-amylphenol, 2-hexylphenol, 2-isohexylphenol, 2-tert-hexylphenol, 2-heptylphenol , 2-octylphenol, 2-alkylphenols such as 2-nonylphenol, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diisopropylphenol, 2,6-
2,6-Dialkylphenols such as di-tert-butylphenol and 2,6-tert-amylphenol can be suitably used.

Examples of the olefin include ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, and 2-methyl-2-. Butene, hexene,
Examples thereof include isohexene, heptene, isoheptene, diisobutylene, octene, isooctene, nonene, decene, isodecene, and dodecene.

Among them, olefins having 1 to 5 carbon atoms are preferable, and isobutylene is particularly preferable.

-Catalyst- Aluminum triphenoxide acting as a catalyst for the reaction between phenols and olefins is represented by the following formula: It is a compound represented by these.

This aluminum triphenoxide can be easily obtained by a known preparation method, for example, stirring phenol and aluminum while heating.

In this case, the amount of aluminum used is usually 0.1 to 30 parts by weight based on 100 parts by weight of phenol.

The heating temperature is usually 100 to 200 ° C, preferably 120 to 180 ° C.

The stirring time is usually 5 to 120 minutes, preferably 10 to 90 minutes.
Minutes.

During the preparation of the catalyst (at the time of heating and stirring), generation of hydrogen gas is observed, whereby the generation of aluminum triphenoxide can be confirmed.

-Reaction conditions- Next, the reaction conditions in the method of the present invention will be described.

The reaction between the phenols and the olefin can be usually carried out without using a solvent, but can be carried out using a suitable solvent if desired.

Such a solvent is not particularly limited as long as it does not hinder the reaction, and various solvents can be used, for example, pentane, hexane, heptane, and inert aliphatic hydrocarbons such as octane. , Cyclohexane,
Inactive alicyclic hydrocarbons such as cycloheptane and the like can be mentioned.

Further, the above reaction can be carried out in the presence of a suitable diluent gas, if desired.

The reaction is suitably carried out at a temperature in the range of usually 30 to 250 ° C, preferably 50 to 180 ° C.

If the reaction temperature is too low, the catalytic activity may not be sufficient. On the other hand, if the reaction temperature is too high, simultaneous occurrence of side reactions may not be negligible.

The reaction pressure is not particularly limited, but is usually from normal pressure to 30.
kg / cm ² (gauge pressure), and preferably from in the range of within the range of 0~20kg / cm ² (gauge pressure).

There is no particular limitation on the reaction system used for the reaction,
It can be performed by any of a semi-continuous system such as a batch system and a semi-batch system, and a continuous circulation system.

When the reaction is performed in a batch system or a semi-batch system, the aluminum triphenoxide of the catalyst used in the reaction is usually 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the phenol used. Use at a rate that falls within the range of parts.

Further, the reaction time is usually in the range of about 0.01 to 10 hours, preferably about 0.5 to 8 hours.

On the other hand, when the reaction is performed by a continuous flow method, the contact time is preferably set so as to be within a range calculated from the reaction time.

The reaction product obtained as described above is subjected to the following post-treatment.

B. Post-Treatment The post-treatment involves mixing the reaction product and the solvent and then performing a plurality of filtration operations.

-Solvent- Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane and heptane, alicyclic hydrocarbons such as cyclohexane and cycloheptane, and aromatic hydrocarbons such as benzene, toluene and xylene. One of these solvents can be used alone, or two or more of them can be used in combination.

Among them, preferred are alicyclic hydrocarbons and aromatic hydrocarbons, and particularly preferred are cyclohexane and toluene.

The amount of the solvent to be added to the reaction product is usually 30 to 1,000 parts by weight, preferably 50 to 500 parts by weight, per 100 parts by weight of the reaction product.

The solvent may be mixed with the reaction product by being charged into the reaction product, or may be mixed with the reaction product by being charged into the solvent.

The mixture of the solvent and the reaction product is then subjected to a multi-stage filtration operation.

-Multi-stage filtration operation- The mixture is subjected to two or more filtration operations, and preferably to three filtration operations. In addition, the said mixture is 1
The object of the present invention cannot be achieved only by performing the filtration operation twice.

First filtration operation Examples of the filter medium used in this filtration operation include ceramic, unglazed plate, diatomaceous earth, asbestos, glass fiber, paper, synthetic fiber, wool, cotton, wire mesh, and alundum.

In this first filtration operation, impurities having a large particle diameter in the mixture are removed.

Therefore, it is preferable that the filter medium has an effective diameter of 2 to 100 μm.

If the effective diameter of the filter medium is smaller than 2 μm, the filtration operation may take a long time to be inefficient, and if the effective diameter is larger than 100 μm, the filtering effect may be reduced.

At the time of filtration, a mixture containing silica as a main component, sawdust, asbestos, paper pulp, activated carbon, talc and the like can be added to the mixture as a filter aid.

The amount of the filter aid to be added can be appropriately determined according to the amount of the mixture within a range not to impair the object of the present invention.

The mixture is filtered through the filter medium with or without the addition of the filter aid.

The filtration may be performed at normal pressure, or may be performed under pressure or suction.

The filtrate (referred to as filtrate I) and the cake (referred to as cake I) are separated by a filtration operation.

 The obtained filtrate I is subjected to a second filtration operation.

Second filtration operation The types of filter media used in the second filtration operation are as follows.
The same as in the filtration operation.

However, since the second filtration operation is intended to remove solid components finer than the solid components removed by the first filtration operation, it is preferable to select a filter medium having an effective diameter of 0.5 to 2 μm. .

If the effective diameter is less than 0.5 μm, the filtration operation takes a long time and is not efficient, and if the effective diameter exceeds 2 μm, the second
There is no point in performing multiple filtration operations.

In order to make the filtration operation efficient, the filter aid used in the first filtration operation may be used.

The filtration may be performed at normal pressure, or may be performed under pressure or suction.

The filtrate (referred to as filtrate II) and the cake (referred to as cake II) are separated by a filtration operation.

 The obtained filtrate II is subjected to a third filtration operation.

Third Filtration Operation The types of filter media used in the third filtration operation are as follows.
The same as in the filtration operation.

However, since the third filtration operation is intended to remove solid components finer than the solid components removed by the second filtration operation, it is necessary to select a filter medium having an effective diameter of 0.05 to 0.5 μm. preferable.

If the effective diameter is smaller than 0.05 μm, the filtration operation takes a long time to be inefficient, and if the effective diameter exceeds 0.5 μm, the third filtration operation is meaningless.

In order to make the filtration operation efficient, the filter aid used in the first filtration operation may be used.

The filtration may be performed at normal pressure, or may be performed under pressure or suction.

The filtrate (referred to as filtrate III) and the cake (referred to as cake III) are separated by a filtration operation.

The obtained filtrate III is subjected to a fourth filtration operation.

Four or more filtration operations In the present invention, the target product alkylphenols can be recovered at a recovery rate of 98% or more by three filtration operations.

However, if the intended product is to be recovered at a higher recovery rate, it is necessary to perform the filtration operation four or more times.

In that case, the type of the filter medium and the type of the filter aid are the same as those used in the first filtration operation. However, it is necessary to select an effective diameter of the filter medium in accordance with the number of filtration stages.

-Isolation of the target product- The final filtrate obtained by the two or more filtration operations, 3
If the filtration operation is repeated twice, the filtrate III is subjected to a usual purification operation to isolate the target alkylphenol.

As the purification operation, distillation operations such as normal pressure distillation, reduced pressure distillation, and rectification are generally used, but other known purification operations can also be employed.

-Recovery of catalyst- On the other hand, it is preferable to collect the cakes obtained by the above-mentioned respective filtration operations into one and subject them to recovery of the catalyst.

That is, for example, the catalyst can be easily recovered simply by washing the cake with phenols as a reaction raw material, and the recovered catalyst can be reused while maintaining the original activity.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example 1) 160 g of phenol and 1.5 g of metal Al were charged into an autoclave having an internal volume of 1,000 ml, reacted at 150 ° C for 30 minutes to prepare aluminum triphenoxide, cooled to 110 ° C, and then press-fitted with 210 g of isobutylene. And reacted for 2 hours. The reaction pressure was at its own pressure. The composition of the reaction product after completion of the reaction was as shown in Table 1.

Next, 600 g of a solvent was added to the reaction product, and the obtained mixture was pressurized (filter pressure: 4 k) using filter paper [filter paper No. 2 for chemical analysis, manufactured by Advantech Toyo Co., Ltd., effective diameter 5.0 μm].
g / cm ² ), the first filtration operation was performed to obtain a filtrate I. This filtrate I was subjected to a second filtration operation under pressure (filtration pressure: 4 kg / cm ² ) using filter paper [filter paper No. 5c for chemical analysis, manufactured by Advantech Toyo Co., Ltd., effective diameter 1.0 μm]. This gave filtrate II. The filtrate II is suctioned using a membrane filter [Advantech Toyo Co., Ltd., membrane filter A020, effective diameter 0.2 μm] (filtration pressure;
A third filtration operation was performed under 20 mmHg) to obtain a filtrate III.

After the solvent was distilled off from the filtrate III, the filtrate
By heating for an hour, an organic phase was obtained. Each component in the organic phase can be separated by precision distillation.

Table 1 shows the content of each component in the organic phase. Table 1 also shows the component compositions of the filtrates I and II. The component composition in each of the filtrates I and II was analyzed by gas chromatography.

-Remarks- As shown in Table 1, the composition in the organic phase did not change even after three filtration operations, and the recovery of each component of the alkylphenol was almost 100%. Also, the Al content in the filtrate was below the detection limit. Further, no modification of the organic phase due to the heat treatment was observed.

As shown in Table 2, the filtration operation was performed very smoothly, and the filtration efficiency was improved.

(Example 2) Instead of using toluene as a solvent, cyclohexane was used.
Except that 600 g was used, the procedure was the same as in the above example.

 The results are shown in Table 3.

-Remarks- As shown in Table 3, the organic phase was not denatured by the filtration operation, and each component was able to achieve a recovery of about 100%. Also, the Al content in the filtrate was below the detection limit. Further, no modification of the organic phase due to the heat treatment was observed.

As shown in Table 4, the filtration operation was performed very smoothly, and the filtration efficiency was improved.

(Comparative Example 1) [Sulfuric acid hydrolysis treatment] An autoclave having an internal volume of 1,000 ml was charged with 160 g of phenol and 1.5 g of metal Al, reacted at 150 ° C for 30 minutes to prepare aluminum triphenoxide, and then cooled to 110 ° C. Then, isobutylene (210 g) was pressurized and reacted for 2 hours. The reaction pressure was at its own pressure. The composition of the reaction product after completion of the reaction was as shown in Table 5.

280 cc of sulfuric acid (7.5% by weight) was added to the reaction product, and 40
When the mixture was stirred for 10 minutes while being heated to ° C., two phases were separated into an organic phase and an aqueous phase. This was separated and the organic phase was washed with an aqueous solution of sodium carbonate (5% by weight) to make it neutral. Table 5 shows the content of each component in the organic phase and the aqueous phase.

-Remarks- As shown in Table 5, in this sulfuric acid hydrolysis treatment, denaturation of the organic phase is observed. In particular, the target product 2,6-DTB
2,4-DTBP difficult to distill due to small boiling point difference from P
Is more remarkable than the other components.

Therefore, the modification to 2,4-DTBP results in a decrease in the yield of the target product.

Comparative Example 2 600 cc of toluene was added to the reaction product obtained in the above Example, and one-stage filtration was performed using filter paper having an effective diameter shown in Table 6.

 The results are shown in Table 6.

[Effect of the Invention] In the method for producing alkylphenols of the present invention, since the reaction product and the solvent are mixed and then subjected to a multi-stage filtration treatment, secondary processes such as rearrangement and disproportionation of the target alkylphenols are performed. This has the advantage that the desired product can be obtained in high yield without causing a reaction and easily separating the organic phase and the aqueous phase.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C07C 37/88 C07C 37/88 // C07B 61/00 300 C07B 61/00 300

Claims (1)

(57) [Claims] 1. A process for producing an alkylphenol, which comprises reacting a phenol with an olefin in the presence of aluminum triphenoxide, wherein a solvent is added to the obtained reaction product, followed by multi-stage filtration. Manufacturing method.