JPH05294875A - Production of bisphenol compounds - Google Patents

Abstract

PURPOSE:To improve the yield, reaction rate, selectivity, etc., of the bisphenol compound by modifying an acidic cation exchange resin charged into a reactor and used for the reaction with a nitrogen-containing sulfur compound so as to give an uniform modification degree over the whole packed bed. CONSTITUTION:A method for producing the bisphenol compound such as bisphenol A by charging raw materials containing a carbonyl compound such as acetone and a phenol compound into a reactor filled in with an acidic cation exchange resin and reacting the raw materials with each other comprises once intermitting the reaction, charging a solution into the reactor for modifying the acidic cation exchange resin with a nitrogen-containing sulfur compound, and then restarting the reaction. The solution is produced by dissolving the nitrogen-containing sulfur compound in the mixed solvent of the phenol and/or the carbonyl compound with an organic compound having a specific dielectric constant of 1.8-5.0. The method enables to readily improve the performance of the acidic cation exchange resin, to improve the yield, selectivity, etc., of the bisphenol compound, and further to reduce or eliminate a mercaptan to be added to the raw materials.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing bisphenols such as bisphenol A. More specifically, it relates to a method for producing bisphenols by modifying a catalyst used for producing bisphenols.

[0002]

BACKGROUND OF THE INVENTION Bisphenols such as bisphenol
Leu A, that is, 2,2-bis (4-hydroxyphenyl) propane, is obtained by reacting acetone with an excess amount of phenol in the presence of an acidic catalyst. As acidic catalysts, in addition to strong acids such as hydrochloric acid, solid acid catalysts such as acidic cation exchange resins are used.In particular, acidic cation exchange resins have not only problems such as equipment corrosion but also Since the reaction yield is excellent, it is widely used. When an acidic cation exchange resin is used as a catalyst, it is common to use a promoter in order to improve the reaction rate, selectivity, etc. Usually, mercaptans are used as a raw material in a mixture. However, since mercaptans have problems such as odor, a method of modifying with a nitrogen-containing sulfur compound having a mercapto group-bonding group with an acidic cation exchange resin such as mercaptoamine is known instead of adding it. (JP-A-56-46831, JP-A-52-19189)
JP-A-57-35533, JP-A-53-1468
No. 0).

Such modification of the acidic cation exchange resin is usually carried out before filling the reactor, but in some cases it may be necessary to be carried out after the start of the reaction.
It is necessary to modify the acidic cation exchange resin only for a part of the acid groups of the acidic cation exchange resin. However, since the filled acidic cation exchange resin cannot be stirred, the solution of the nitrogen-containing sulfur compound cannot be stirred. There is a problem that only the layer on the upstream side of the flowing stream is modified and the downstream side is not modified. Moreover, the modified upstream layer has a problem that the modification rate is too high.

As a method for uniformly modifying the acidic cation exchange resin packed in the reactor, Japanese Patent Laid-Open No. 53-1468.
Japanese Patent Laid-Open No. 0 proposes to make a uniform modification in advance and then homogenize it by flowing an acidic aqueous solution for a sufficient time. However, this method is not only time consuming, it requires a fairly high flow rate and there are some problems such as equipment corrosion due to the use of acid.

[0005]

SUMMARY OF THE INVENTION In the present invention, the acidic cation exchange resin packed in a reactor and used in the reaction is modified with a nitrogen-containing sulfur compound so as to have a uniform modification rate throughout the packed bed. , The yield of bisphenols, the reaction rate, the selectivity, etc. are improved.

[0006]

According to the present invention, a raw material containing a carbonyl compound and a phenol compound is charged into a reactor filled with an acidic cation exchange resin and reacted to produce a bisphenol compound. In the method described above, the reaction is once suspended, and a solution obtained by dissolving a nitrogen-containing sulfur compound in a mixed solvent of a phenol compound and / or a carbonyl compound and an organic compound having a relative dielectric constant of 1.8 to 5.0 is prepared. A method for producing bisphenols, which comprises charging an acidic cation exchange resin with a nitrogen-containing sulfur compound in a reactor and then restarting the reaction.

Bisphenols include bisphenols.
Examples of the carbonyl compound include aldehydes and ketones, and examples of the phenols include phenol, cresol, and xylen which do not have a substituent at the para position with respect to the hydroxyl group. There are such as Le. Preferably,
The present invention can be applied to the production of bisphenol A using acetone and phenol as raw materials.

The acidic cation exchange resin used as a catalyst is preferably a sulfonic acid type resin, and as a base resin, a styrene-divinylbenzene copolymer system, a perfluorocarbon type resin is used.
There are fluorethylene copolymer system, phenol-formaldehyde polymer system, etc., but styrene-divinylbenzene copolymer system is common. The acidic cation exchange resin used in the present invention is not limited to this, and any strongly acidic cation exchange resin can be used. And, in this, a part of the acid group may be modified with a nitrogen-containing sulfur compound. The acidic cation exchange resin is loaded into the reactor to form a fixed bed.

The above raw materials are flowed into this reactor to continuously carry out the reaction. During this reaction, mercaptans may be mixed in the raw material. When the nitrogen-containing sulfur compound needs to be modified by carrying out such a reaction, the modification of the present invention is carried out. In addition, when the modification is required, the modification is performed before the filling, but the modification rate is lowered due to the modification, the modification is not performed initially, but it is determined that the modification is desirable. . In such a case, the reaction is temporarily stopped and the modification is carried out by the following method.

The nitrogen-containing sulfur compound used for modification is a compound having a group capable of binding to an acidic cation exchange resin and a mercapto group, such as mercaptoamine or its precursor as described above. Specifically, alkyl mercaptoamines such as thioethanolamine and propylmercaptoamine, aminothiocarboxylic acids or esters thereof such as cysteine, cyclic mercaptoamines such as aminothiophenol, pyridine alkanethiols, etc. Can be mentioned. As the precursor, there is a thiazolidine compound that produces mercaptoamines. When this nitrogen-containing sulfur compound comes into contact with an acidic cation exchange resin, it rapidly undergoes an ion exchange reaction and bonds. The modification in the present invention means this, and the modification rate is represented by an ion exchange rate, and it is generally said that 10 to 40% of acid groups such as sulfonic acid groups should be ion-exchanged.

When the above-mentioned nitrogen-containing sulfur compound is made into a solution such as an aqueous solution, and this solution is flowed through a packed bed of acidic cation exchange resin, modification proceeds from the upstream side, and even if the upstream side proceeds 100%,
The downstream reaction is often almost 0%. In the present invention, in order to make this uniform, a solution containing a nitrogen-containing sulfur compound dissolved in a specific solvent is passed through the packed bed. As the solvent, one or both of a carbonyl compound such as acetone as the above-mentioned raw material and phenols are mixed with an organic compound having a relative dielectric constant of 1.8 to 5.0. Relative permittivity is 1.8-
Examples of the organic compound of 5.0 include aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane and methylcyclohexane. These organic compounds may be used alone or as a mixture, but those which are compatible with the nitrogen-containing sulfur compound and the carbonyl compound or the phenols are preferable. Further, the compounding amount in the solvent is 5 to 30.
% Is appropriate. The concentration of the nitrogen-containing sulfur compound in the solution is
About 1 to 15 wt% is suitable. The amount of the solution used is preferably such that the amount of the nitrogen-containing sulfur compound is a calculated amount sufficient to bring the acidic cation exchange resin to a predetermined modification rate.

The acid cation exchange resin can be modified by pouring the solution of the nitrogen-containing sulfur compound into a reactor filled with the resin so that the whole solution is immersed. In this case, the solution may be circulated while flowing,
The valve at the reactor outlet may be closed to collect the solution.
The temperature is room temperature to 100 ° C., and the contact time is about 1 to 50 hours. After the modification is completed, the reaction is restarted after washing and the like.

[0013]

It is considered that the presence of an organic compound having a relatively low relative dielectric constant in the solution slows down the ion exchange rate and allows uniform modification.

[0014]

【Example】

Example 1 A sulfonic acid type acidic cation exchange resin 90 washed with phenol on a metal column having an inner diameter of 20 mm and a length of 300 mm.
ml was filled. While maintaining the inside of the column at 60 ° C., the concentration of 2-mercaptoethylamine from the upper part of the column is 6.8 wt.
% Phenol / toluene = 90/10 (wt ratio) solution was poured at LHSV = 1, and after confirming that the inside of the column was filled with this solution, the valve at the bottom of the column was closed and left for 30 hours. . Then, the inside of the column was washed with phenol. 10 ml from the top of the column, 10 m from the bottom
The acid cation exchange resin (1) was taken out and the modification ratio with 2-mercaptoethylamine was measured. As a result, 21% of the sulfonic acid groups in the upper part and 18% of the sulfonic acid groups in the lower part were measured.
% Was ion-exchanged and was almost uniformly modified. On the other hand, when a solution using only phenol as a solvent was used, 95% of the sulfonic acid groups were ion-exchanged in the upper part and 0.5% of the sulfonic acid groups were ion-exchanged in the lower part, resulting in non-uniform modification. It had been.

[0015]

According to the production method of the present invention, the performance of the acidic cation exchange resin can be easily improved, and the yield and selectivity of bisphenols can be improved. Further, the mercaptans added to the raw material can be reduced or eliminated.

Claims (1)

[Claims] 1. A method for producing a bisphenol by charging a raw material containing a carbonyl compound and a phenol into a reactor filled with an acidic cation exchange resin, and reacting the raw material, to suspend the reaction. Then, a solution prepared by dissolving a nitrogen-containing sulfur compound in a mixed solvent of a phenol compound and / or a carbonyl compound and an organic compound having a relative dielectric constant of 1.8 to 5.0 is charged into the reactor and acidified. A method for producing bisphenols, which comprises modifying a cation exchange resin with the nitrogen-containing sulfur compound and then restarting the reaction.