JPH10212257A - Production of bisphenol a - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing bisphenol A by which the deterioration in catalyst activities is hardly caused even in the coexistence of an alcohol when reacting acetone with phenol in the presence of a strongly acidic ion exchange resin catalyst partially modified with a sulfur-containing amine compound. SOLUTION: Water in an amount of 0.05-0.5wt.% is contained in a raw material mixture and the water concentration in the raw material mixture is continuously or intermittently reduced within the above range with time in a method for reacting the raw material mixture comprising acetone and phenol in the presence of a strongly acidic ion exchange resin catalyst partially modified with a sulfur-containing amine compound and producing bisphenol A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing bisphenol A.

[0002]

2. Description of the Related Art In producing bisphenol A by reacting acetone with an excess of phenol, it is widely used to use a strongly acidic ion-exchange resin partially modified with a sulfur-containing amine compound as a catalyst. . When reacting acetone and phenol using such a catalyst, if alcohol is mixed into the acetone used,
This alcohol reacts with the sulfur-containing compound which acts as a catalyst promoter, thereby reducing its action as a promoter and deteriorating the catalytic activity. Such deterioration of the catalyst activity causes regeneration of the catalyst or replacement of the catalyst with a new catalyst, and causes a significant reduction in the economics of the process.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a method for reacting acetone and phenol in the presence of a strongly acidic ion-exchange resin catalyst partially modified with a sulfur-containing amine compound, even when an alcohol is present. It is an object of the present invention to provide a method that is less likely to cause degradation of the activity of the steel.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in a method for producing bisphenol A by reacting a raw material mixture comprising acetone and phenol in the presence of a strongly acidic ion exchange resin catalyst partially modified with a sulfur-containing amine compound, A method for producing bisphenol A, comprising adding 0.05 to 0.5% by weight of water to a mixture and continuously or intermittently reducing the water concentration in the raw material mixture over time within the above range. A method is provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Bisphenol A used in the present invention
The production catalyst is composed of a strongly acidic ion exchange resin partially modified with a catalytic promoter composed of a sulfur-containing amine compound. In this case, examples of the strongly acidic ion exchange resin include a sulfonic acid type cation exchange resin. Such a sulfonic acid type cation exchange resin is conventionally well-known, and a gel type or a porous type can be used, but a gel type is preferably used. The degree of crosslinking is from 2 to 16%, preferably from 2 to
It is better to set it in the range of 6%. The average particle size is usually 0.2 to 2 mm, preferably 0.4 to 1.5.
mm. Such an unmodified sulfonic acid type cation exchange resin is already commercially available, and, for example, Amberlite and Amberlyst manufactured by Rohm and Haas Co., Ltd., Dayaion manufactured by Mitsubishi Kasei, and the like can be preferably used.

The sulfur-containing compound used as the catalyst promoter is also a well-known compound, for example, mercaptoalkylpyridines such as 3-mercaptomethylpyridine, 3-mercaptoethylpyridine and 4-mercaptoethylpyridine; 2-mercaptoethylamine , 3-mercaptobutylamine, 3-n-propylamino-1-propylmercaptan, and other mercaptoalkylamines (or aminoalkylmercaptans); thiazolidine, 2,2-dimethylthiazolidine, cycloalkylthiazolidine, 2-methyl-2-phenylthiazolidine Thiazolidines such as 1,3-methylthiazolidine; 1,4
And aminothiophenol such as aminothiophenol. Particularly preferred are 2-mercaptoethylamine and 2,2-dimethylthiazolidine. The above-mentioned sulfur-containing amine compound can be an addition salt of an acidic substance such as hydrochloric acid or a quaternary ammonium salt.

The modification of the strongly acidic ion exchange resin can be carried out by reacting the resin with a sulfur-containing compound in water or an organic solvent. As the organic solvent, phenol or acetone can be used, but it is preferably performed in water. As the reaction temperature, room temperature or heating is employed, and the reaction time is not particularly long, and a few minutes is sufficient. It is preferable to stir the reaction mixture to make the reaction uniform. This reaction is preferably carried out so that a part of the sulfone groups contained in the unmodified resin, usually 3 to 30%, preferably 5 to 15%, is converted to a modified group.

In order to carry out the method of the present invention, a raw material mixture comprising acetone and phenol is continuously supplied to a reactor filled with the partially modified strongly acidic ion exchange resin catalyst. While the packed bed is circulated, the reaction between acetone and phenol is carried out during that, and the obtained reaction product containing bisphenol A is continuously withdrawn from the reactor. The reaction temperature is a temperature higher than the melting point of phenol, usually 40 to 100C, preferably 55 to 85. The reaction pressure is from 1 to 1.5 atm, preferably from normal pressure to slight pressure. The reaction time is 15 to 200 minutes, preferably 50 to 120 minutes. The amount of phenol used is 8 to 20 mol, preferably 10 to 1 mol, per mol of acetone.
6 moles.

In the present invention, 0.05 to 0.5 wt% of water in the raw material mixture coexists in the reaction system, and the amount of the water is as high as 0.5 wt% at the stage immediately after the start of the reaction. It is preferable that water having the same concentration is used. The amount of this water is
A method is preferred in which the reaction is continued and the continuous crotch is reduced intermittently as the activity decreases. If the amount of water coexisting in the reaction system is more than the above range, the catalytic activity is conversely reduced. On the other hand, if the amount is too small, the reaction between the alcohol and the sulfur-containing compound cannot be effectively prevented. The alcohol present in acetone is mainly methanol, but a small amount of isopropyl alcohol may be present in some cases. As described above, the reaction of the alcohol with the sulfur-containing compound as a promoter (mainly the dehydration of the mercapto group (SH) and the alcohol) is carried out by allowing water to exist in the reaction system at an appropriate concentration corresponding to the activity of the catalyst. Reaction), and a decrease in the activity of the catalyst can be prevented. Water can be added to the reaction system by pre-existing water in the raw material acetone or raw material phenol.In addition, a water supply pipe must be attached to the reactor and the water be supplied through this water supply pipe. Can be.

In the present invention, an operation is carried out to reduce the concentration of water contained in the raw material mixture continuously or intermittently over time in the above concentration range. This operation of lowering the water concentration does not need to be performed over the entire reaction operation time, and can be performed only for a fixed time from the start of the reaction operation. In order to preferably perform the water concentration lowering operation, first, the water concentration in the raw material mixture is set to its upper limit value or near its upper limit value, and the water concentration is gradually or continuously decreased intermittently with time.

As described above, by performing the operation of decreasing the water concentration in the raw material mixture over time, the water concentration can be adjusted in accordance with the level of decrease in the activity of the bisphenol A production catalyst. In addition, it is possible to effectively suppress the deterioration of the activity of the bisphenol A production catalyst while always maintaining the activity of the catalyst.

[0012]

Next, the present invention will be described in more detail with reference to examples.

Example 1 A cylindrical container having an inner diameter of 120 mm and a height of 1.5 m was provided with a perforated plate (perforated plate: about 0.1 mm) at the top and bottom, and a space between the perforated plates. Was used as a reactor. As a catalyst in this case, a sulfonic acid type cation exchange resin (average particle size: 0.5 mm, 10% of sulfonic acid groups of trade name “Amberlite IR-118-H” was reacted with 2-mercaptoethylamine. From the top of the reactor, 10 mL of methanol was added.
A reaction mixture comprising 4.7 wt% of acetone containing 00 wt ppm and 95.3 wt% of phenol was introduced, and a reaction product containing bisphenol A was extracted from the bottom of the reactor. In this case, the reaction temperature was 70 ° C., and the contact time between the catalyst and the mixed solution was 70 minutes. In this case, water was added to the reaction mixture to a concentration of 0.5 wt%. afterwards,
Each time the catalytic activity decreases by 1%, the water concentration is reduced to 0.1 wt.
An operation of decreasing by% was performed. As a result, an acetone conversion of 88% was obtained in the initial stage of the reaction, and at the 3000th hour (water concentration: 0.1 wt%), the acetone conversion of 88% was maintained.

Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that water was not added. As a result, 92%
Was obtained, but after 3000 hours,
The acetone conversion dropped to 85%.

Comparative Example 2 An experiment was conducted in the same manner as in Example 1 except that the water concentration was maintained at 0.5 wt% without performing the operation of lowering the water concentration. As a result, an acetone conversion of 88% was obtained at the beginning of the reaction, but after 3000 hours, the acetone conversion was reduced to 84%.

[0016]

According to the present invention, since the concentration of water contained in the raw material mixture is reduced with time, it is possible to effectively suppress the decrease in the catalytic activity for producing bisphenol A. Bisphenol A can be produced in high yield.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Sachio Asaoka 2-1-1, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Chiyoda Kako Construction Co., Ltd. Chiyoda Chemical Works, Ltd. (72) Inventor Keiji Maehara 2-1-1, Tsurumi Chuo, Tsurumi-ku, Yokohama

Claims (1)

[Claims] 1. A process for producing bisphenol A by reacting a raw material mixture comprising acetone and phenol in the presence of a strongly acidic ion exchange resin catalyst partially modified with a sulfur-containing amine compound, comprising the steps of: 0.
A method for producing bisphenol A, characterized by containing 0.5 to 0.5% by weight of water and decreasing the water concentration in the raw material mixture continuously or intermittently over time within the above range.