JPH11269114A - Production of bisphenol compounds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a bisphenol compound from a phenol compound and a carbonyl compound, capable of improving the life of a catalyst and further capable of improving selectivity. SOLUTION: This method for producing a bisphenol compound comprises condensing a phenol compound with a carbonyl compound in the presence of an acid catalyst such as a cation exchange resin and a mercaptan compound. Therein, the mercaptan compound is preliminarily treated with an acid. The mercaptan compound is especially preferably treated with a solid acid such as an ion exchange resin, activated clay or zeolite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing bisphenols, and more particularly, to the production of bisphenols from phenols and carbonyl compounds, which can improve the catalyst life and selectivity. And a process for producing bisphenols.

[0002]

2. Description of the Related Art Bisphenols are known to be important compounds as raw materials for polymers.
2,2- which is a typical compound among bisphenols
Bis (4-hydroxyphenyl) propane (bisphenol A) is used as a raw material for engineering plastics such as polycarbonate resin and polyarylate resin, or epoxy resin, and in recent years, its demand has been increasing more and more. The bisphenols are usually produced by condensing excess phenols with a carbonyl compound in the presence of a cocatalyst such as an acid catalyst and a sulfur compound. As the acid catalyst used in this reaction, inorganic mineral acids such as sulfuric acid and hydrogen chloride have been used in the past, but cation exchange resins have recently attracted attention (British Patent Nos. 842209 and 849).
No. 565, No. 883391) and have been used industrially.

On the other hand, sulfur compounds used as cocatalysts include methyl mercaptan, ethyl mercaptan,
Alkyl mercaptans having or not having a substituent such as thioglycolic acid are known to be effective (US Pat. Nos. 2,359,242 and 277).
No. 5620). These mercaptans have the effect of increasing the reaction rate and increasing the selectivity. For example, in the case of bisphenol A, 2- (2-hydroxyphenyl) -2- (4
- hydroxyphenyl) propane (o, p ^'- form) is produced, other trisphenol, polyphenol is produced. In particular, when used as a raw material such as a polycarbonate resin or a polyarylate resin, the content of these by-products is small, and high purity bisphenol A without coloring is used.
Is required. For this reason, while increasing the reaction speed,
Mercaptans are used as co-catalysts in order to suppress the generation of the by-products and increase the selectivity.

On the other hand, it is known that when a phenol is reacted with a carbonyl compound using a cation exchange resin as a catalyst and a mercaptan as a cocatalyst, a cyclic dimer is by-produced, and In order to suppress the by-product of the cyclic dimer, a method of adding mercaptans in a stepwise manner has been disclosed (JP-A-2-17144). By the way, when bisphenol A is produced industrially, a raw material mixture containing phenol, acetone and a cocatalyst mercaptan is usually continuously supplied to a reaction tower filled with a cation exchange resin from the viewpoint of production efficiency. To produce bisphenol A. However, in such a reaction mode, there is a problem that the use of mercaptans deteriorates the cation exchange resin of the catalyst and shortens the catalyst life. In the method of adding mercaptans in a stepwise manner, this reduction in catalyst life cannot be suppressed. Prolonging the catalyst life is extremely important in industrial production.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for producing a bisphenol by condensing a phenol and a carbonyl compound in the presence of an acid catalyst and mercaptans in such a situation. While suppressing the selectivity of the target bisphenols, for example, when using a cation exchange resin as an acid catalyst,
It is an object of the present invention to provide a method for producing bisphenols, which can suppress catalyst deterioration and extend catalyst life.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have noticed that impurities contained in mercaptans degrade the acid catalyst and shorten its life. Then, the mercaptans are previously treated with an acid to remove impurities, and then subjected to a reaction,
It has been found that the catalyst life can be extended by suppressing the deterioration of the acid catalyst, and the selectivity of the target bisphenol can be improved. The present invention has been completed based on such findings. That is, the present invention is characterized in that, in the presence of an acid catalyst and mercaptans, a phenol and a carbonyl compound are condensed to produce bisphenols, and as the mercaptans, those previously treated with an acid are used. The present invention provides a method for producing bisphenols.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing bisphenols of the present invention, the phenol used as a raw material may be a monovalent aromatic hydroxy compound which is condensed with a carbonyl compound described below to form a bisphenol. There is no particular limitation, and it may be appropriately selected according to the desired bisphenols. Examples of such phenols include:
Phenol; o-cresol; m-cresol; o-chlorophenol; m-chlorophenol; o-ethylphenol; m-ethylphenol; 2,5-xylenol; 3,5-xylenol;
2,5-di-tert-butylphenol; 2,6-di-tert-butylphenol
Butylphenol; o-phenylphenol and the like. On the other hand, the carbonyl compound is not particularly limited as long as it is capable of condensing with the phenols to form bisphenols, and may be appropriately selected according to the desired bisphenols. Examples of the carbonyl compound include acetone; ethyl methyl ketone; isobutyl methyl ketone; acetophenone; 1,3-dichloroacetone; hexafluoroacetone; cyclohexanone.

In the method of the present invention, it is particularly preferable to use phenol as the phenol and acetone as the carbonyl compound. By using these raw materials, bisphenol A which is an industrially important compound can be obtained. . The use ratio of the phenols and the carbonyl compound is not particularly limited, but the amount of the unreacted carbonyl compound is desirably as small as possible from the viewpoint of easiness of purification and economical efficiency of the produced bisphenols. It is advantageous to use phenols in excess of stoichiometric amounts. Depending on the type of raw material, usually, per mole of carbonyl compound,
3 to 30 moles, preferably 5 to 20 moles of phenols are used. In addition, in the production of the bisphenols, the reaction solvent is, except that the reaction solution is reacted at a low temperature such that the viscosity of the reaction solution is too high or the operation is difficult due to solidification
Generally not required.

In the present invention, an acid catalyst and a co-catalyst, mercaptans, are used in the condensation reaction between the phenols and the carbonyl compound. As the acid catalyst,
Any one of known acid catalysts conventionally used in the production of bisphenols can be selected and used, but from the viewpoint that the effects of the present invention are effectively exerted and the production efficiency is good. Cation exchange resins are preferred. Among these cation exchange resins, a sulfonic acid type cation exchange resin is particularly preferable from the viewpoint of catalytic activity and the like. The sulfonic acid type cation exchange resin is not particularly limited as long as it is a strongly acidic cation exchange resin having a sulfonic acid group. Examples thereof include a sulfonated styrene-divinylbenzene copolymer, a sulfonated crosslinked styrene polymer, and phenol formaldehyde-sulfone. Acid resin and benzene formaldehyde-sulfonic acid resin. These may be used alone or in combination of two or more.

On the other hand, mercaptans as co-catalysts include:
Alkyl mercaptans, carboxyl groups, amino groups,
Alkyl mercaptans having at least one substituent such as a hydroxyl group, for example, mercaptocarboxylic acid, aminoalkanethiol, mercaptoalcohol and the like can be used. Examples of such mercaptans include alkyl mercaptans such as methyl mercaptan, ethyl mercaptan, n-butyl mercaptan, and n-octyl mercaptan; thiocarboxylic acids such as thioglycolic acid and β-mercaptopropionic acid; and 2-aminoethanethiol. And a mercapto alcohol such as mercaptoethanol. Of these, alkyl mercaptans are particularly preferred in view of the effect as a cocatalyst. Further, these mercaptans may be used alone or in combination of two or more.

In the present invention, it is necessary to treat the mercaptans with an acid in advance before removing the mercaptans to remove impurities contained therein. The acid used in this treatment is not particularly limited, but is preferably treated with a solid acid from the viewpoints of effect and treatment efficiency. Preferred examples of the solid acid include ion exchange resins, activated clay, natural and synthetic zeolites, and the like, and cation exchange resins are particularly preferable in terms of effect. Examples of the cation exchange resin include the same ones as exemplified in the description of the acid catalyst. As a treatment method, any of a batch method and a continuous method may be used, but from the viewpoint of treatment efficiency, it is advantageous to continuously supply mercaptans to a treatment tower filled with solid acid to remove impurities. It is. In this case, as the processing conditions, LHSV (liquid hourly space velocity) is preferably 0.01～100Hr ^-1, more preferably selected in the range of 0.5～5Hr ^-1, The processing temperature is preferably Is -20 to 80 ° C, more preferably 0 to 5
It is selected in the range of 0 ° C. The processing pressure is not particularly limited, but generally, the processing is performed at normal pressure.

Thus, by treating the mercaptans with an acid and removing impurities contained therein,
The deterioration of the cation exchange resin of the acid catalyst can be suppressed, the catalyst life can be improved, and the selectivity of the target bisphenol can be improved. The amount of the mercaptan treated in this manner varies depending on the type of the raw material, the reaction conditions and the like, but is generally 0.05 to 30 mol%, preferably 0 to 30 mol%, based on the carbonyl compound of the raw material. It is in the range of 0.1 to 20 mol%. The condensation reaction between the phenol and the carbonyl compound in the present invention may be either batchwise or continuous. However, from the viewpoint of production efficiency, the phenol and the carbonyl compound are added to a reaction column filled with a cation exchange resin as an acid catalyst. And a raw material mixture containing the acid-treated mercaptans and the above-mentioned acid-treated mercaptans. At this time, one or more reaction towers may be arranged in series. However, industrially, two or more reaction towers filled with a cation exchange resin are arranged in series and a fixed bed is used. It is particularly advantageous to employ a multi-stage continuous reaction system.

The reaction conditions in the fixed bed continuous reaction system are appropriately selected according to the type of bisphenol to be produced. Hereinafter, the case of producing bisphenol A will be described. First, the acetone / phenol molar ratio is
It is usually selected in the range of 1/30 to 1/3, preferably 1/15 to 1/5. If the molar ratio is smaller than 1/30, the reaction rate may be too slow. If the molar ratio is larger than 1/3, the generation of impurities increases, and bisphenol A
Tends to decrease. On the other hand, the mercaptans / acetone molar ratio is usually 0.1 / 100 to 20/10.
0, preferably in the range of 1/10 to 10/100. When the molar ratio is smaller than 0.1 / 100, the effect of improving the reaction rate and the selectivity of bisphenol A may not be sufficiently exhibited. When the molar ratio is larger than 20/100, the effect is not improved much for the amount. unacceptable. The reaction temperature is usually 40 to 150 ° C, preferably 60 to 11 ° C.
It is selected in the range of 0 ° C. If the temperature is lower than 40 ° C., the reaction rate is low, and the viscosity of the reaction solution is extremely high, which may cause solidification. ), The cation exchange resin of the catalyst may be decomposed or deteriorated. Furthermore, the LHSV of the raw material mixture
Is usually 0.2 to 30 Hr ^-1 , preferably 0.5 to 10 Hr
Selected in the range of ^-1 .

[0014] In this manner, the reaction mixture coming out of the reaction tower is subjected to a post-treatment by a known method, and bisphenol A is taken out. Next, an example of this post-treatment will be described. First, concentration is performed prior to crystallization. The concentration conditions are not particularly limited, but are usually at a temperature of 130 to 1
The concentration is performed at 70 ° C. and a pressure of 100 to 400 torr. If the temperature is lower than 130 ° C., a high vacuum is required,
If the temperature exceeds 170 ° C., impurities may increase or coloring may occur. The concentration of bisphenol A in the concentrated residue is 25%.
Advantageously it is in the range of ４０40% by weight. If this concentration is less than 25% by weight, the recovery of bisphenol A is low,
If it exceeds 40% by weight, it becomes difficult to transfer the slurry after crystallization. Crystallization of an adduct of bisphenol A and phenol from the concentrated residue is usually performed by vacuum cooling crystallization in which cooling is performed using the latent heat of evaporation of water under reduced pressure. In this vacuum cooling crystallization method, about 3 to 20% by weight of water is added to the concentrated residue, and the temperature is usually 40 to 70 ° C. and the pressure is 20 to 1%.
The crystallization process is performed under the condition of 00 torr. If the amount of water added is less than 3% by weight, the heat removal ability is not sufficient,
If the content is more than 20% by weight, the dissolution loss of bisphenol A increases, which is not preferable. If the crystallization temperature is lower than 40 ° C., the viscosity of the crystallization liquid may increase or solidify.
If the temperature exceeds ℃, the dissolution loss of bisphenol A increases, which is not preferable.

Next, the thus-crystallized adduct of bisphenol A and phenol is separated by a known method, and is usually washed with phenol. Next, the washed adduct was replaced with bisphenol A.
In this case, the temperature is usually selected in the range of 130 to 200 ° C, preferably 150 to 180 ° C, while the pressure is generally selected in the range of 20 to 150 torr. Bisphenol A obtained by this decomposition treatment is substantially completely removed from the residual phenol therein by a method such as steam stripping, so that high-quality bisphenol A can be obtained.

[0016]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 In a cylindrical container having an inner diameter of 10 mm and a length of 500 mm, a cation exchange resin [sulfonated styrene-divinylbenzene copolymer, manufactured by Bayer, trade name: Levatit K1]
221] 10 ml was charged, and n-butyl mercaptan was continuously supplied at a flow rate of 10 ml / hr at room temperature to remove impurities with an acid catalyst. Next, a cylindrical container having an inner diameter of 10 mm and a length of 1500 mm was filled with 50 ml of a cation exchange resin [sulfonated styrene-divinylbenzene copolymer, manufactured by Bayer, trade name: Levatit K1221]. Acetone and n after the above treatment
-Butyl mercaptan at 300 g / hr, 1
Continuously flow at 8.5 / hr and 1 g / hr, 80
The reaction was performed at ℃.

At the start of the reaction, the acetone conversion is 75%,
The selectivity for p, p'-bisphenol A was 96.0%. 168 hours after the start of oil passage, the acetone conversion rate was 7
The selectivity for 3% and p, p'-bisphenol A was 96.1%. Comparative Example 1 The procedure of Example 1 was repeated, except that n-butyl mercaptan, which had not been subjected to the treatment for removing impurities with an acid catalyst, was used. The conversion of acetone at the start of the reaction was 75%. , P, p'-Bisphenol A selectivity was 94.5%. 168 hours after the start of oil passage, the selectivity did not decrease, but the acetone conversion decreased to 60%. Comparative Example 2 A cylindrical container having an inner diameter of 10 mm and a length of 1500 mm was filled with 60 ml of the same cation exchange resin as in Example 1, and was not subjected to a phenol, acetone, and impurity removal treatment using an acid catalyst. -Butyl mercaptan at 300 g / hr, 18.5 / hr and 1 g / hr, respectively.
The reaction was carried out at 80 ° C. by continuously flowing at a flow rate of hr. At the start of the reaction, the conversion of acetone was 78%, and the selectivity for p, p'-bisphenol A was 94.3%. Oil passing started 168
After time, there was no decrease in selectivity, but the acetone conversion had dropped to 65%.

[0018]

According to the method of the present invention, when a phenol and a carbonyl compound are condensed to produce a bisphenol, the formation of by-products can be suppressed and the selectivity of the target bisphenol can be improved. In particular, when a cation exchange resin is used as an acid catalyst, the deterioration of the catalyst is suppressed,
The catalyst life can be extended.

Claims (5)

[Claims] 1. A method for producing a bisphenol by condensing a phenol and a carbonyl compound in the presence of an acid catalyst and a mercaptan,
A process for producing bisphenols, which comprises using a product previously treated with an acid. 2. The method according to claim 1, wherein the acid catalyst is a cation exchange resin. 3. The process for producing bisphenols according to claim 1, wherein the mercaptans are treated with a solid acid. 4. The process according to claim 3, wherein the solid acid is an ion exchange resin, activated clay or zeolite. 5. The method according to claim 1, wherein the mercaptan is an alkyl mercaptan.