JP3326530B2 - Catalyst and method for isomerization of bisphenols - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for catalytically converting an isomer of a bisphenol other than the desired bisphenol to the desired bisphenol, which is by-produced in the production of the bisphenol. Regarding the isomerization method of by-product bisphenols using a catalyst, more specifically, a carbonyl compound and a phenol,
In the presence of an acidic ion-exchange resin or an acidic catalyst such as hydrochloric acid, by-products of bisphenols produced during the production of bisphenols, to smoothly and efficiently target isomers of bisphenols other than the intended bisphenols The present invention relates to a method for improving the yield of a target bisphenol by catalytically converting to bisphenol, and a catalyst therefor.

[0002]

BACKGROUND OF THE INVENTION Among bisphenols, para-bisphenol A, that is, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as p, p'-BPA) is particularly preferred. Is a substance useful as a raw material for polycarbonate resins and epoxy resins, and in recent years, its use and demand have greatly increased. p, p'-BPA is produced, for example, by condensing a carbonyl compound such as acetone with a phenol represented by phenol in the presence of an acidic ion exchange resin or an acidic catalyst such as hydrochloric acid or sulfuric acid. At that time, the desired p, p'-BPA
And 2- (2-hydroxyphenyl) -2- (4-hydroxyphenyl) propane (hereinafter referred to as o, p'-BPA
), Trisphenol, IPP dimer, chromans, unidentified tar-like substances, and the like are produced as a large amount to significantly reduce the yield of the target p, p'-BPA. In order to improve the yield of the desired p, p'-BPA, by-products that can be relatively easily converted to the desired p, p'-BPA such as o, p'-BPA and trisphenol are used. It is necessary to isomerize to the desired p, p'-BPA in the presence of an acidic catalyst as in the main reaction in the synthesis of bisphenol.

As a catalyst for this isomerization reaction, an unmodified sulfonic acid type strongly acidic ion exchange resin and, for example,
It is known to use acidic ion exchange resins partially modified with lower aminothiols such as aminoethanethiol. However, in this case, the rate of the isomerization reaction is low, and there is a disadvantage that the conversion to the target p, p'-BPA is low.

JP-A-57-114540 discloses an isomerization method using a sulfonic acid type cation exchange resin modified with a mercaptoalkylpyridinium salt. Japanese Patent Application Laid-Open No. 1-135736 discloses an isomerization method using a cation exchange resin modified with an alkyl mercaptoamine having two mercapto groups in one molecule.
However, all have the drawback that the modifier is a substance that is hardly available and is expensive. In order to put these isomerization reactions into practical use, they are easily available,
It is necessary to promote the reaction smoothly and efficiently using an inexpensive denaturing agent. An object of the present invention is to provide an isomerization method for efficiently and smoothly converting an undesired by-product to a desired bisphenol.

[0005]

[Means for Solving the Problems and Action] The present inventors have conducted intensive studies on a process for isomerizing isomers of bisphenols by-produced and a catalyst therefor, and as a result, they are relatively easily available. By using, as a catalyst, a strongly acidic ion exchange resin partially modified with inexpensive mercapto-thiazolines, the isomerization reaction can proceed surprisingly, smoothly and efficiently, and the by-products can be formed. And the degree of coloring is kept low, and the desired p,
The inventors have found that the yield of p'-BPA can be greatly improved, and based on this finding, have reached the present invention. That is, the first invention is a bisphenol isomerization catalyst characterized by being a strongly acidic ion exchange resin in which an acidic functional group is partially modified in advance with a mercapto-thiazoline represented by the formula ( 1 ). Further, the second invention uses , as a catalyst, isomers of bisphenols other than the target bisphenols which are by-produced in the production of bisphenols by condensing a carbonyl compound with phenols. In the isomerization method of converting the isomer of the bisphenol into the desired bisphenol by contacting the first invention with the first invention,
And a bisphenol isomerization catalyst .

[0006] [Wherein, R ^{1 to} R ⁵ are each independently a hydrogen atom, a hydroxyl group,
Amino group, nitro group, carbonyl group, carboxyl group,
It represents an acetyl group, a sulfone group, an alkyl group, a cycloalkyl group, an allyl group or a mercapto group. However, R ¹ ~
At least one among R ⁵ is mercapto group. ]

The bisphenols intended in the present invention are not particularly limited, but usually, for example, carbonyl compounds such as acetone, methyl ethyl ketone, acetophenone and chloroacetone, and phenol, o-cresol, m-cresol, for example. And phenols such as o-chlorophenol, o-phenylphenol, o-tert.-butylphenol and 2,4-xylenol, for example, in the presence of an acidic ion exchange resin and an acidic catalyst such as hydrochloric acid and sulfuric acid. Although it is obtained by a condensation reaction according to the method, bisphenol A obtained from phenol and acetone is practically preferable.

In the present invention, the acidic functional group of the strongly acidic ion exchange resin is used as an isomerization catalyst by partially modifying the acidic functional group (hereinafter, “modification” means modification of the acidic functional group). The exchange resin may be a so-called strongly acidic ion exchange resin, and is not particularly limited. The degree of acidity of the ion-exchange resin, which is determined by the amount of the acidic functional group of the ion-exchange resin and the degree of dissociation, is expressed as the logarithm of the reciprocal of the dissociation constant (Ka), that is, pKa, as is usually performed. The pKa can be measured, for example, by a conventional method using a caustic soda aqueous solution of known concentration. The degree of acidity before denaturation of the strongly acidic ion exchange resin used in the present invention is usually less than about 3 as pKa, preferably about 1. Representative examples of the strongly acidic ion exchange resin used in the present invention include a sulfonic acid type strongly acidic ion exchange resin having styrene-divinylbenzene, crosslinked styrene, phenol-formaldehyde, or benzene-aldehyde resin as a resin matrix. Can be mentioned. Further, as the strongly acidic ion exchange resin, any of a giant net (MR type) resin and a micro net (Gel type) resin can be used. Above all, a sulfonic acid type styrene-divinylbenzene cation exchange resin is preferably used. As a preferred representative example of a sulfonic acid type styrene-divinylbenzene-based cation exchange resin, K122
1 ( a product of Bayer AG: Gel type), MSC-1 ( a product of Dow Chemical Company: MR type) and Amberlyst 31 ( a product of Rohm and Haas company: Gel type) . Cash on these cation-exchange resins listed as a table example, substantially, has the cation exchange ability of 3.0~6.0meq / g, in general, because they are commercially available as Na-type, in the present invention In order to use it as a catalyst, it is necessary to convert it into the H form in advance with an acid such as hydrochloric acid.

[0009] In the present invention, modifiers for modifying the strongly acidic ion-exchange resin is represented by the formula (1) Melka
Put-thiazolines .

[0010] [Wherein, R ^{1 to} R ⁵ are each independently a hydrogen atom, a hydroxyl group,
Amino group, nitro group, carbonyl group, carboxyl group,
It represents an acetyl group, a sulfone group, an alkyl group, a cycloalkyl group, an allyl group or a mercapto group. However, R ¹ ~
At least one among R ⁵ is mercapto group. ]

Of these, 2-mercapto-thiazoline is most preferred because it is relatively inexpensive and relatively easy to obtain in large quantities.

In the present invention, the modification rate of the strongly acidic ion exchange resin is practically 70% or less, preferably less than 30% with respect to acidic functional groups such as sulfonic acid groups in the strongly acidic ion exchange resin. It is particularly preferably from 10% to less than 30%, most preferably from 10 to 25%. If the modification rate is too low, the strongly acidic ion exchange resin is hardly modified, and when such a strongly acidic ion exchange resin is used, the isomerization reaction does not proceed smoothly. On the other hand, even when the modification rate is 30% or more, the isomerization reaction rate, that is, the recovery rate and the yield of the target bisphenols such as p, p'-BPA, increase in proportion to the increased modification rate. And no substantial difference from the case where the modification rate is less than 30%. Further, when the modification ratio exceeds 70%, the isomerization reaction is rather reduced.

In the modification of the strongly acidic ion exchange resin, the denaturing agent, mercapto-thiazoline, quantitatively ion-bonds to the acidic functional group of the strongly acidic ion exchange resin. The amount required for denaturation can be easily determined by calculation from both the resin amount of the strongly acidic ion exchange resin to be denatured and the amount of the acidic functional group—that is, pKa.

The modification of the strongly acidic ion exchange resin in the present invention may be carried out by contacting the strongly acidic ion exchange resin with a modifier. When the denaturing agent used is insoluble in water, usually, the strongly acidic ion exchange resin to be denatured is air-dried or heated and then immersed in phenol for 50 to 1 hour.
This is carried out by maintaining the temperature at 00 ° C. to sufficiently swell, adding a predetermined amount of a denaturing agent thereto, and stirring for about 0.1 to 5 hours. In this way, the denaturation reaction can be completed in a short time, but a ripening period may be required to spread the denaturation evenly in the strongly acidic ion exchange resin. Also,
If the denaturant used is water-soluble, without drying the strongly acidic ion exchange resin, while immersing the strongly acidic ion exchange resin in the water-containing state in water, adding the denaturant to this , And denaturation is carried out in the same manner as described above except that the temperature is maintained at 50 to 80 ° C.

The isomerization in the present invention may be carried out by contacting an isomer other than the desired bisphenol with a modified strongly acidic ion exchange resin as a catalyst, and the synthesis reaction of the bisphenol containing the isomer may be carried out. The product solution or the isomer separated from the synthesis reaction product solution may be mixed with a denaturing agent, but the former is preferred. The isomerization reaction in the present invention is usually carried out in an inert gas atmosphere at normal pressure to 5 kg / cm ² G
Under pressure of about 40 to 120 ° C., preferably 6 ° C.
It is performed in a temperature range of about 0 to 100 ° C. If the reaction temperature in the isomerization reaction is too low, the activity of the catalyst will not be sufficiently exhibited, and the reaction rate will decrease, requiring a long reaction time.
On the other hand, if the reaction temperature is too high, the reaction rate becomes sufficiently high, but the amount of by-products increases, and o, p'-BPA
/ P, p'-BPA ratio increases. However,
It does not prevent the reaction conditions from being out of the range. The amount of the catalyst used depends on the type of bisphenols, the type of catalyst, the degree of modification, and the reaction conditions such as the reaction pressure and the reaction temperature, and cannot be specified, but is based on the weight of the isomer of the bisphenols to be isomerized. On the other hand, usually 0.
It is about 5 to 10 times.

The time required for the isomerization can be appropriately selected depending on the type and amount of the strongly acidic ion exchange resin, the type of the modifier, the degree of the modification, and the reaction conditions such as the reaction pressure and the reaction temperature. In the case of 0.1 to 0.1
In the case of a continuous reaction using a fixed bed, the space velocity (SV) is about 0.1 to 20 / hr.

In addition, at the time of isomerization, if a small amount of water is present in the reaction system, the amount of impurities generated can be reduced. On the other hand, the water content is 2
When the content is more than 10% by weight, the reaction rate of the isomerization reaction decreases,
Long reaction times are required. Therefore, the water content in the isomerization reaction solution is usually about 0.1 to 1% by weight, preferably about 0.1% by weight.
It is preferable to maintain it at about 1 to 0.7% by weight. In order to maintain the water content in the isomerization reaction liquid within this range, usually, the corresponding water is added to the isomerization reaction liquid.
By performing such operations, the isomerization reaction can proceed very efficiently.

[0018]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless the gist is changed.

Example 1 In a 500 ml round-bottomed flask, a sufficiently dried H-type sulfonic acid type styrene-divinylbenzene-based cation exchange resin (K1221 manufactured by Bayer AG: ion exchange capacity 5.2 meq / g,
Mix 30 g of pKa 1.0) with 150 g of phenol,
After swelling while stirring for 3 hours in a water bath at 2 ° C., 2-mercapto-thiazoline (manufactured by Junsei Chemical: MW 119.2)
1.9 g of 1) was added, and 2 more
The denaturation reaction solution was obtained by continuing the time denaturation. From the denaturation reaction product, 30 g of a strongly acidic ion exchange resin modified by removing phenol by filtration was obtained. The acidic functional groups of the thus modified strongly acidic ion exchange resin were quantified by titration using an aqueous sodium hydroxide solution, and it was confirmed that the modification rate was 10%. The whole amount of the denatured strongly acidic ion exchange resin was placed in a 300 ml round bottom flask, 120 g of an isomerization reaction solution having the composition shown in Table 1 was charged, and the solution was sufficiently stirred at 80 ° C. under normal pressure. And reacted. After 6 hours from the start of the reaction, the stirring was stopped, the resin component was removed from the obtained reaction product by filtration, and the amounts of o, p'-BPA and p, p'-BPA in the filtrate were measured. The results shown in Table 1 were obtained.

Example 2 The amount of 2-mercapto-thiazoline used was changed from 1.9 g to 4.
8g, and the modification rate of the strongly acidic ion exchange resin was about 25
%, And the results shown in Table 1 were obtained.

Example 3 The amount of 2-mercapto-thiazoline used was changed from 1.9 g to 9.
5 g, and the modification rate of the strongly acidic ion exchange resin was about 50
%, And the results shown in Table 1 were obtained.

Example 4 The amount of 2-mercapto-thiazoline used was changed from 1.9 g to 1
Changed to 3.3 g, and modified the strongly acidic ion exchange resin
Table 1 was obtained in the same manner as in Example 1 except that the value was 0%.
Were obtained.

Comparative Example 1 Instead of 1.9 g of 2-mercapto-thiazoline, 1.2 g of 2-amino-ethanethiol (manufactured by Junsei Chemical Co., Ltd., MW 77.11)
Approximately 10% denaturation rate of strongly acidic ion exchange resin using
The procedure was performed in the same manner as in Example 1 except that the results shown in Table 1 were obtained.

Comparative Example 2 Except for using a strongly acidic ion exchange resin that was not denatured,
The procedure was performed in the same manner as in Example 1, and the results shown in Table 1 were obtained.

[0025]

[Table 1]

When these examples are compared with comparative examples, in the isomerization method of the present invention using a strongly acidic ion exchange resin modified with a mercapto-thiazoline as a modifier as a catalyst, the mercapto as a modifier is used. -Isomerization compared to isomerization using a strongly acidic ion exchange resin modified with a substance other than thiazolines as a catalyst and isomerization using a strongly acidic ion exchange resin not modified as a catalyst. It can be seen that the conversion is proceeding smoothly and efficiently.

[0027]

EFFECT OF THE INVENTION By using the isomerization catalyst of the present invention, isomers other than the target bisphenols which are by-produced when bisphenols are produced by condensing a carbonyl compound with phenols can be efficiently produced. In addition, it can be smoothly isomerized and converted into the desired bisphenol, thereby improving the yield of the desired bisphenol.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 21/00-37/36 C07C 39/00

Claims (6)

(57) [Claims] 1. A bisphenol isomerization catalyst characterized by being a strongly acidic ion exchange resin in which an acidic functional group is partially modified in advance with a mercapto-thiazoline represented by the formula (1). [Wherein, R ^{1 to} R ⁵ are each independently a hydrogen atom, a hydroxyl group,
Amino group, nitro group, carbonyl group, carboxyl group,
It represents an acetyl group, a sulfone group, an alkyl group, a cycloalkyl group, an allyl group or a mercapto group. However, R ¹ ~
At least one among R ⁵ is mercapto group. ] 2. The bisphenol isomerization catalyst according to claim 1, wherein the strongly acidic ion exchange resin is a sulfonic acid type cation exchange resin. 3. A process according to claim 1 or 2, wherein the isomerization catalyst of bisphenol modification ratio of the acid functional group is 70% or less. 4. Mercapto - thiazolines is 2-mercapto - thiazoline a is claims 1 to 3 according to any one of the isomerization catalyst of bisphenols. 5. An isomer of a bisphenol other than a target bisphenol which is by-produced when a bisphenol is produced by condensing a carbonyl compound and a phenol with a catalyst to convert the isomer of the bisphenol In the isomerization method of converting the desired bisphenols,
The bis catalyst according to any one of claims 1 to 4, which is used as the catalyst.
A method for isomerizing bisphenols, comprising using a phenol isomerization catalyst . 6. The method for isomerizing bisphenols according to claim 5 , wherein the target bisphenol is bisphenol A.