JP2009196929A - Method for producing bisphenols - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing bisphenols in the presence of a modified IER (Ion Exchange Resin) catalyst, by which the bisphenols can stably be produced for a long period in a state preventing the deterioration of the catalyst without needing a high cost. <P>SOLUTION: Provided is the method for producing the bisphenols, comprising reacting phenol with a 1-6C compound A having a carbonyl group in the presence of a strongly acidic cation exchange resin, characterized in that the concentration of an alcohol contained in the above compound A is 300 to 1,000 ppm; the concentration of water contained in reaction raw materials obtained by mixing the phenol with the compound A is ≤0.2 wt.%; 10 to 20% of the acid sites of the strongly acidic cation exchange resin is modified with a sulfur-containing compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing bisphenols.

  Bisphenols, especially bisphenol A [2,2-bis (4-hydroxyphenyl) propane], is useful as a raw material for polycarbonate resins and epoxy resins, and in recent years, its demand has greatly increased. Bisphenol A is obtained by condensing phenol and acetone in the presence of an acid catalyst. Bisphenols are compounds having two phenol structures in the molecule, obtained by condensing phenols and carbonyl compounds.

  The production of bisphenols has been conventionally performed by a method using a homogeneous acid such as hydrogen chloride as a catalyst, but in recent years, with the enlargement of the plant, a strongly acidic cation exchange resin with a low equipment cost is used as a catalyst. A method using a thiol compound as a co-catalyst (hereinafter also referred to as “IER (Ion Exchanging Resin) catalyst method”) has become the mainstream (see, for example, Patent Documents 1 and 2).

  In the IER catalyst method, a thiol compound as a co-catalyst is added to a reaction raw material (a mixture of phenol and acetone) and supplied (co-catalyst addition method), and the thiol compound is added to a strongly acidic cation exchange resin catalyst There is a method (hereinafter referred to as a denaturing IER method) that is used after being immobilized (hereinafter referred to as denaturing) by ion exchange or the like.

  In the cocatalyst addition method, alkylthiols, mercaptopropionic acid and the like are suitably used as the cocatalyst. On the other hand, in the modified IER method, a sulfonic acid type ion exchange resin is usually used as a strongly acidic cation exchange resin, and aminoalkyl thiols and pyridine thiols are suitably used as co-catalysts.

  In the cocatalyst addition method, the thiol compound flows out of the strongly acidic cation exchange resin together with the reaction solution, and is mixed in a subsequent step such as a step of separating the unreacted raw material and the product. The mixed thiol compound is usually removed from the reaction solution by distillation or the like, but cannot be completely separated, and the product may contain the thiol compound. It is known that when a thiol compound is mixed in product bisphenols, its quality, particularly hue, is deteriorated.

  On the other hand, such a situation does not occur in the modified IER method. For this reason, especially when it is desired to obtain high-quality bisphenols, a modified IER method is often used for the production of bisphenols. However, the use of a strongly acidic IER catalyst modified with a thiol compound, that is, a modified IER catalyst, reduces the risk of contamination with the thiol compound in the product, but the modified IER method adds a promoter to the reaction solution during the reaction. Since it cannot be performed, it is susceptible to the deterioration of the promoter. If the cocatalyst deteriorates, the activity of the modified IER catalyst also decreases, that is, the modified IER catalyst also deteriorates. When the modified IER catalyst deteriorates, naturally, the modified IER catalyst must be replaced, which increases costs.

  The thiol compound as a cocatalyst deteriorates due to alteration of the thiol group due to oxygen, alcohols, organic impurities generated by the reaction, and the like. For example, in acetone used for the production of bisphenol A (both have a boiling point that is difficult to completely remove by purification by distillation), a trace amount of methanol is mixed. It is necessary to keep it below a certain value.

  Regarding the methanol concentration in acetone in the production of bisphenol A, a method for suppressing the methanol concentration in acetone to 10000 ppm or less has already been disclosed (Patent Document 3). Patent Document 4 discloses a method for producing bisphenol by first purifying monophenol and carbonyl compounds as raw materials, and suppressing substances that act as alkylating agents such as methanol to 0.1% or less. Has been.

  Methanol in acetone is usually removed by distillation. However, since the boiling points of both are close, it is usually very difficult to completely separate them. From the standpoint of suppressing catalyst deterioration, a lower methanol concentration is desirable, but a large-scale distillation facility is required for high purification. Therefore, it is necessary to set an optimal value as the methanol concentration in acetone in consideration of the balance between the cost required for purification and the advantage of suppressing catalyst deterioration.

Further, in the production of bisphenol A, a method of changing the methanol concentration in acetone according to the concentration of water in the reaction raw material (Patent Document 5) and a catalyst modification rate (ratio of modifying the acid point of IER) are determined by acetone. There is also known a method (Patent Document 6) for changing the concentration according to the concentration of methanol therein. Since the concentration of water in the reaction raw material and the modification rate of the catalyst mainly affect the activity of the modified IER catalyst, it is necessary to set the optimum value in consideration of the economics of the entire process together with the methanol concentration. .
JP 2004-10666 A Japanese Patent Laid-Open No. 10-218814 Japanese Patent Laid-Open No. 06-09889 Japanese Patent Laid-Open No. 06-025047 JP-A-10-175898 JP 2002-255880 A

  An object of the present invention is to provide a method for producing bisphenols stably for a long period of time in a method for producing bisphenols using a modified IER catalyst, without inhibiting catalyst deterioration without incurring a large cost.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the compound having 1 to 6 carbon atoms having one carbonyl group, more specifically, the alcohol concentration contained in acetone or the like, the water in the reaction raw material, It has been found that the above problems can be solved by setting optimum values for the concentration and the catalyst modification rate, and the present invention has been completed.

  That is, the present invention is a process for producing bisphenols in which phenol and a compound A having 1 to 6 carbon atoms having one carbonyl group are reacted in the presence of a strongly acidic cation exchange resin, The concentration of the alcohol contained in the reaction mixture is 300 to 1000 ppm, the concentration of water contained in the reaction raw material in which the phenol and the compound A are mixed is 0.2 wt% or less, and the acid of the strongly acidic cation exchange resin A method for producing bisphenols, characterized in that 10 to 20% of the points are modified with a sulfur-containing compound.

  The sulfur-containing compound used in the present invention is selected from the group consisting of a compound represented by the following general formula (a), a compound represented by the following general formula (b), and a compound represented by the following general formula (c). It is preferably at least one selected.

In the above formula (a), R ₁ ~R ₃ each independently represent a hydrogen atom, an alkyl group or an aryl group having a carbon number of 6 to 12 of carbon atoms 1 to 10, n is an integer from 1 to 10 And A represents a nitrogen atom or a phosphorus atom.

In the above formula (b), R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group or an aryl group having 6 to 12 carbon atoms of 1 to 10 carbon atoms, n represents an integer of 1 to 10 And A represents a nitrogen atom or a phosphorus atom.

In said formula (c), m represents the integer of 1-20.
The strongly acidic cation exchange resin is preferably a sulfonic acid type ion exchange resin.

  According to the present invention, deterioration of the modified IER catalyst can be suppressed without incurring a large cost, and bisphenols can be produced stably at a low cost and with a sufficient conversion rate for a long period of time.

Hereinafter, the contents of the present invention will be described in detail.
[Strongly acidic cation exchange resin]
In the method for producing bisphenols of the present invention, a strongly acidic cation exchange resin is used as a catalyst. Here, “strongly acidic” refers to having an exchange group that dissociates in water and exhibits strong acidity, like mineral acids such as hydrochloric acid and sulfuric acid.

  As the strongly acidic cation exchange resin (strongly acidic IER) used in the present invention, a styrene-divinylbenzene copolymer into which a sulfone group is introduced (sulfonic acid type strongly acidic IER) is preferably used.

In general, sulfonic acid type strongly acidic IER is Levacit (registered trademark) (LANXESS), Dowex (registered trademark) (Zadau Chemical Company), Amberlite (registered trademark) (Rohm and Haas).・ Sold under the trade name of Japan Co., Ltd. or Diaion (registered trademark) (Mitsubishi Chemical Corporation).

  There are two types of sulfonic acid type strongly acidic IERs, one having a fine network structure (gel type) and one having a huge network structure (macroporous type), both of which can be used in the present invention.

  The mole fraction of divinylbenzene relative to styrene is called the degree of crosslinking, and the gel type is generally 2-8% and the macroporous type is generally 8-20%. The macroporous type has a high degree of crosslinking, and the pores of the sulfonic acid type strongly acidic IER are clogged by organic impurities generated by the synthesis reaction of bisphenols, and the performance as a catalyst thereof is likely to deteriorate. A gel type having a crosslinking degree of 2 to 4% is preferably used as the sex IER.

[Sulfur-containing compounds]
The sulfur-containing compound used in the present invention is a promoter, and the activity and selectivity of the catalyst can be improved by modifying the strongly acidic IER with the sulfur-containing compound.

  Examples of the sulfur-containing compound include a compound having a thiol group. The sulfur-containing compound is represented by the following general formula (a), the following general formula (b), and the following general formula (c). It is preferable that it is at least 1 sort (s) chosen from the group which consists of a compound.

In formula (a), R _{1 to} R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and n represents an integer of 1 to 10. , A represents a nitrogen atom or a phosphorus atom.

In formula (b), R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and n represents an integer of 1 to 10 , A represents a nitrogen atom or a phosphorus atom.

In formula (c), m represents an integer of 1-20.
Preferable examples of the compound represented by the general formula (a) include N, N, N-trimethylmercaptopropylammonium, N, N, N-trimethylmercaptoethylammonium, 3-mercaptopropyltriphenylphosphonium and 4-mercapto. Butyltriphenylphosphonium,
Preferable examples of the compound represented by the general formula (b) include 2-mercaptoethylamine (cysteamine), 3-mercaptopropylamine and N, N-dimethyl-3-mercaptopropylamine.
Preferable examples of the compound represented by the general formula (c) include 3-mercaptomethylpyridine, 3- (2-mercaptoethyl) pyridine and 4- (2-mercaptoethyl) pyridine.

  The ratio of modifying the strongly acidic IER with the sulfur-containing compound is 10 to 20%, preferably 15 to 20% of the acid point of the strongly acidic IER. If the modification rate is too small, the effect as a promoter cannot be sufficiently obtained. In addition, when the cocatalyst is deactivated due to deterioration, there is a problem that it is easily affected. On the other hand, if the modification rate is too high, most of the acid sites of the strongly acidic IER that is the main catalyst will be crushed, and the catalytic activity will be lowered.

  The method for partially modifying the strongly acidic cation exchange resin with the sulfur-containing compound is not particularly limited, and a known method can be employed. For example, by reacting a strongly acidic cation exchange resin and a sulfur-containing compound in a suitable solvent so as to have a predetermined modification amount (modification rate), a strongly acidic cation modified by 10 to 20% of the acid point is obtained. An ion exchange resin can be obtained. The amount of the catalytic acid point is determined by stirring the modified strong acidic cation exchange resin in an aqueous sodium chloride solution, etc., and removing the proton group from the unmodified acid point by ion exchange. After removing by filtration, the amount of protons in the aqueous solution is titrated with an aqueous sodium hydroxide solution and measured. For the unmodified catalyst and the modified catalyst, the modification rate can be confirmed by measuring the amount of acid sites.

  As described in [Background Art], the cause of deterioration of the cocatalyst includes organic impurities generated by the synthesis reaction of oxygen, alcohols, and bisphenols. Oxidizing agents such as oxygen are considered to disulfide the thiol group of the promoter and lose its activity. In addition, alkylating agents such as alcohols are thought to lose their activity by alkylating thiol groups. It is considered that the organic impurities generated by the synthesis reaction also bind to the thiol group by some reaction and lose its activity.

[Compound A having 1 to 6 carbon atoms having one carbonyl group]
Examples of the compound A having 1 to 6 carbon atoms which reacts with phenol in the present invention (hereinafter also simply referred to as compound A) include ketones having 1 to 6 carbon atoms and aldehydes having 1 to 6 carbon atoms. . Specific examples of the ketone include acetone, methyl ethyl ketone, and methyl isobutyl ketone, and specific examples of the aldehyde include formalin and acetaldehyde. Among these, preferred is acetone, and when compound A is acetone, bisphenol A can be produced by the production method of the present invention.

  The alcohol concentration in the compound A is 300 to 1000 ppm, preferably 300 to 800 ppm, based on the entire compound A containing alcohol. If the alcohol concentration is too high, the catalyst will be deteriorated faster, the frequency of catalyst replacement will increase, and the economics of the process will be significantly impaired. The alcohol concentration in Compound A can be adjusted to the above range by purifying with a distillation column having about 20 to 40 theoretical plates, for example.

From the viewpoint of catalyst deterioration, the alcohol concentration should be lower, but the boiling point of the alcohols in the compound A is usually close to the boiling point of the compound A, and it is difficult to separate the compound A and the alcohols. Therefore, in order to make the alcohol concentration very low, specifically 300 ppm or less, for example, in the case of the most general distillation purification, distillation is carried out in a state almost close to the total reflux by a distillation column having several tens of theoretical plates. Is not practical from the viewpoint of cost. Alcohol concentration of 300 to 1000 ppm can be achieved with equipment having a theoretical number of 20 to 40 distillation columns, although it depends on the alcohol concentration in the raw material. And if alcohol concentration of such a range is achieved, catalyst deterioration can fully be prevented and strong acidic IER can be used for a long period of time.

[Concentration of water in reaction raw material]
The concentration of water in the reaction raw material of the present invention is 0.2 wt% or less. The reaction raw material is a mixed solution of phenol and compound A. Usually, the raw material phenol and compound A contain about 0.1 wt% of water, and the phenol and compound A recovered in the process also contain water. Water is mixed into phenol and compound A.

  Water in the reaction raw material reduces the acid strength of a strongly acidic IER (hereinafter also referred to as a modified strongly acidic IER) modified with a sulfur-containing compound, and lowers its catalytic activity. When the concentration of water in the reaction raw material is 0.2 wt% or less, there is almost no effect on the conversion rate and selectivity to bisphenols, but when it exceeds 0.2 wt%, the conversion rate decreases.

  The concentration of water in the reaction raw material can be adjusted to 0.2 wt% or less by appropriately selecting purification conditions when recovering and reusing unreacted phenol and compound A mainly from the process.

[Method for producing bisphenols]
In the present invention, phenol and compound A are reacted with a specific modified strongly acidic IER.
The ratio of phenol and compound A used in the present invention is not particularly limited, but is usually 0.1 to 100, preferably 0.5 to 50, more preferably 3 to "phenol" / "compound A" (molar ratio). A range of 30.

  Although reaction temperature is not specifically limited, Usually, 0-200 degreeC, Preferably it is 30-150 degreeC, More preferably, it is the range of 40-90 degreeC. If the reaction temperature is too low, the reaction rate may decrease, and if the reaction temperature is too high, undesirable side reactions and the like may proceed, resulting in an increase in by-products and a decrease in reaction selectivity.

The reaction pressure is not particularly limited, but is usually atmospheric pressure to 0.6 MPaG, preferably 0.2 to 0.5 MPaG.
The reaction can be carried out in any of batch, semi-batch and continuous flow methods. The reaction can be carried out in any form of a liquid phase, a gas phase, and a gas-liquid mixed phase, but it is preferably carried out in a liquid phase from the viewpoint of reaction efficiency.

  Various methods such as a fixed bed, a fluidized bed, a suspension bed, and a shelf fixed bed can be employed as the catalyst (modified strongly acidic IER) filling method. From the viewpoint of reaction efficiency, it is desirable to use a fixed bed reactor for the reaction.

The catalyst is usually charged into the reactor in a water-swollen state. And before starting manufacture of bisphenols, phenol is distribute | circulated to a reactor and the water in a catalyst is substituted with phenol.
Phenol and compound A are supplied to the reactor as a reaction raw material in the form of a mixed solution, and flow through the catalyst, thereby producing bisphenols. As described in [Background Art], bisphenols are compounds obtained by condensing phenols and carbonyl compounds and having two phenol structures in the molecule, and are preferably produced by the production method of the present invention. The bisphenol is bisphenol A.

When a fixed bed type reactor is used, the supply ratio of the reaction raw material to the catalyst (LHSV; the ratio of the reaction raw material volume supplied per unit time to the unit volume of the water swelling modified strong acidic IER) is usually 0.1 to 2.0 h ^-1, preferably in the order of 0.3~1.0h ^-1. When LHSV is 0.1 h ⁻¹ or less, the reaction time becomes longer than necessary, and the selectivity of the desired bisphenols may decrease. On the other hand, if it is 2.0 h ⁻¹ or more, a sufficient conversion rate may not be obtained, which is not practical.

  The production method of the bisphenols of the present invention is carried out under the conditions described above, and the three parameters of the alcohol concentration in Compound A, the water concentration in the reaction raw material, and the modification rate of the strongly acidic cation exchange resin by the sulfur-containing compound are determined. By optimizing, bisphenols can be produced stably for a long period of time at a low cost and with a sufficient conversion rate.

  Specifically, a conversion rate of usually 60% or more, preferably 70% or more can be achieved with a single catalyst for a long period of usually 6000 hours or more, preferably 8000 hours or more. In industrial production of bisphenols, a conversion rate of 60% or more is generally required. However, the method for producing bisphenols of the present invention satisfies this requirement, and the use period of the catalyst (strongly acidic IER) is long.

  Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[Example 1]
To a reactor with an external jacket (made by SUS) having an inner diameter of 15 mm and a height of 600 mm, a sulfonic acid type ion exchange resin (K1221, manufactured by LANXESS) modified with 19% of acid points with 4-mercaptobutyltriphenylphosphonium. 15 ml of water swollen was filled.

Next, the reactor was kept warm at 70 ° C. with a jacket, and phenol was passed through the reactor at LHSV = 0.6 h ⁻¹ for 10 h to replace the water in the sulfonic acid type ion exchange resin (catalyst) with phenol.

Next, a reaction liquid mixture of phenol and acetone is put into a reactor in which the catalyst is continuously charged under the conditions of phenol / acetone molar ratio = 10, LHSV = 0.6 h ⁻¹ , reaction temperature 70 ° C. Then, phenol and acetone were reacted to obtain bisphenol A. The water concentration in the reaction raw material was adjusted to 0.15 wt%. The methanol concentration in acetone was adjusted to 500 ppm by adding methanol to the reagent acetone. Water concentration is determined by Karl Fischer titration moisture measurement, and methanol concentration in acetone is determined by gas chromatography (
Column: TC Science, Inc. TC-WAX).

The concentration of water contained in the reaction raw material was 0.15 wt%, and the methanol concentration in acetone was 500 ppm.
The composition at the outlet of the reactor is liquid chromatography (column: manufactured by GL Sciences Inc.)
As a result of analysis by Inertsil ODS-3, eluent: acetonitrile, the conversion rate of raw material acetone was 95% and the selectivity of bisphenol A was 93.0%. When this reaction was continued for 3000 hours, the acetone conversion after 3000 hours was 85%, and the selectivity for bisphenol A was 92.7%.

[Example 2]
In Example 1, except that sulfonic acid type ion exchange resin (K1221, manufactured by LANXESS) modified with 19% of acid point with 4- (2-mercaptoethyl) pyridine was used as a catalyst. The same operation was performed. The acetone conversion at the beginning of the reaction was 91%, the selectivity for bisphenol A was 92.7%, the acetone conversion after 3000 hours was 79%, and the selectivity for bisphenol A was 92.6%.

[Example 3]
In Example 1, the same operation as in Example 1 except that a sulfonic acid type ion exchange resin (K1221, manufactured by LANXESS) modified with 19% of acid point with 3-mercaptopropyltrimethylammonium was used as a catalyst. Went. The acetone conversion at the beginning of the reaction was 90%, the selectivity for bisphenol A was 92.6%, the acetone conversion after 3000 hours was 80%, and the selectivity for bisphenol A was 92.5%.

[Comparative Example 1]
In Example 1, the same operation was performed except that water was added to the reaction raw material and the water concentration in the raw material was changed to 0.3 wt%. The acetone conversion at the beginning of the reaction was 85%, the selectivity for bisphenol A was 92.9%, the acetone conversion after 3000 hours was 70%, and the selectivity for bisphenol A was 92.5%.

[Comparative Example 2]
In Example 1, the same operation was performed except that the methanol concentration in acetone was 1500 ppm. The acetone conversion at the beginning of the reaction was 95% and the selectivity for bisphenol A was 92.9%, which was the same as in Example 1. However, after 3000 hours, the acetone conversion decreased to 55%. The selectivity for bisphenol A after 3000 hours was 92.0%.

[Comparative Example 3]
In Example 1, the same operation was carried out except that a sulfonic acid type ion exchange resin (K1221, manufactured by LANXESS Co., Ltd.) in which 7% of the acid point was modified with 4-mercaptobutyltriphenylphosphonium was used as a catalyst. The acetone conversion at the beginning of the reaction was 85%, the selectivity for bisphenol A was 92.0%, the acetone conversion after 3000 hours was 70%, and the selectivity for bisphenol A was 91.5%.

[Comparative Example 4]
In Example 1, the same operation was performed except that a sulfonic acid type ion exchange resin (K1221, manufactured by LANXESS Co., Ltd.) in which 30% of acid points were modified with 4-mercaptobutyltriphenylphosphonium was used as a catalyst. The acetone conversion at the beginning of the reaction was 85%, the selectivity for bisphenol A was 92.1%, the acetone conversion after 3000 hours was 75%, and the selectivity for bisphenol A was 91.8%.

Claims (3)

A method for producing bisphenols, comprising reacting phenol with a C1-C6 compound A having one carbonyl group in the presence of a strongly acidic cation exchange resin,
The concentration of the alcohol contained in the compound A is 300 to 1000 ppm,
The concentration of water contained in the reaction raw material in which the phenol and the compound A are mixed is 0.2 wt% or less,
A method for producing bisphenols, wherein 10 to 20% of the acid sites of the strongly acidic cation exchange resin are modified with a sulfur-containing compound. The sulfur-containing compound is at least one selected from the group consisting of a compound represented by the following general formula (a), a compound represented by the following general formula (b), and a compound represented by the following general formula (c). The method for producing bisphenols according to claim 1, wherein:

Wherein (a), R ₁ ~R ₃ each independently represent a hydrogen atom, an alkyl group or an aryl group having a carbon number of 6 to 12 of carbon atoms 1 to 10, n is an integer from 1 to 10 And A represents a nitrogen atom or a phosphorus atom. ]

[In Formula (b), R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and n represents an integer of 1 to 10 And A represents a nitrogen atom or a phosphorus atom. ]

[In the formula (c), m represents an integer of 1 to 20. ].   The method for producing bisphenols according to claim 1 or 2, wherein the strongly acidic cation exchange resin is a sulfonic acid type ion exchange resin.