JP7435115B2 - Method for producing bisphenol and method for producing polycarbonate resin - Google Patents

Description

The present invention relates to a method for producing bisphenol from an aromatic alcohol and a ketone or aldehyde. More specifically, it relates to a method for producing bisphenol, which includes a step of distilling and recovering aromatic hydrocarbons used as a solvent in the reaction and purification to produce bisphenol, and using the recovered solvent to wash a solid substance containing bisphenol. be. The present invention also relates to a method for producing a polycarbonate resin using bisphenol obtained by the above-mentioned method for producing bisphenol.

Bisphenol is useful as a raw material for polymeric materials such as polycarbonate resins, epoxy resins, and aromatic polyester resins. As typical bisphenols, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, and the like are known (Patent Document 1). Furthermore, a method for producing bisphenol using sulfuric acid instead of hydrogen chloride gas, which is highly corrosive and requires special equipment, is known (Patent Document 2).

JP2008-214248A JP2019-99581A

Bisphenol is used in a wide range of applications as a raw material for various resins such as polycarbonate resin, and its applications are expected to expand in the future. Therefore, there is a need to more efficiently produce high quality bisphenol. In Patent Document 2, the selectivity of aromatic alcohols is improved by preventing side reactions of aromatic alcohols.

The present inventors recovered a recovered solvent by distillation from the crystallization filtrate discharged when producing bisphenol by the method described in Patent Document 2, and attempted to produce bisphenol using this recovered solvent. It has been found that the quality (polymerization activity) of the obtained bisphenol may deteriorate. Therefore, it has been found that the method of Patent Document 2 has room for improvement in order to more efficiently produce bisphenol.

Under such circumstances, there has been a need for a method for producing bisphenol that produces bisphenol of good quality using a recovered solvent obtained by distilling and recovering the organic solvent used in the production of bisphenol.
The present invention was made in view of these circumstances, and aims to recycle the organic solvent used in a method for producing bisphenol from an aromatic alcohol and a ketone or aldehyde, and to produce bisphenol of good quality. The purpose is to provide a method that can be used.
Another object of the present invention is to provide a method for producing polycarbonate resin using the above bisphenol.

As a result of intensive studies to solve the above problems, the present inventors added a basic compound to the crystallization filtrate, distilled it to recover a recovered solvent, and used this recovered solvent to recover bisphenol. The inventors have discovered that it is possible to produce bisphenol of good quality even when the recovered solvent is reused, leading to the present invention.

That is, the present invention relates to the following inventions.
<1> A method for producing bisphenol, comprising the following steps (A1) to (A4).
Step (A1): In the presence of an acid catalyst, an aromatic alcohol is reacted with a ketone or an aldehyde to produce bisphenol. Step (A2): The bisphenol obtained in the step (A1) reacts with an aromatic hydrocarbon. Solid-liquid separation of the slurry solution (S) dispersed in the solvent containing the bisphenol to obtain the solid content (C) containing the bisphenol and the solution (e) containing the aromatic hydrocarbon Step (A3): the aromatic hydrocarbon Distilling the distillation raw material (D), which is a mixture of a solution (E) containing at least a part of the hydrocarbon-containing solution (e) and a basic compound, to recover an aromatic hydrocarbon recovery solvent (R). Step (A4): A step of washing the bisphenol-containing solid content (C) using a washing solvent containing the recovery solvent (R) to obtain bisphenol <2> The step (A2) and the step (A3) has a step (y1) between
In the step (A1), a reaction is carried out in a reaction liquid (L1) containing an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, and a ketone or aldehyde, and the bisphenol produced is precipitated, and the bisphenol is dispersed. A step of obtaining a slurry reaction product liquid (S1),
The step (A2) is a step in which the slurry reaction product liquid (S1) is subjected to solid-liquid separation to obtain the solid content (C1) containing the bisphenol and the solution (e1-1) containing the aromatic hydrocarbon. can be,
In the step (y), the solution (e1-1) containing the aromatic hydrocarbon or the mixed solution (e1-2) of the solution (e1-1) and a basic aqueous solution is mixed with the aqueous phase (yW) and the A step of separating the organic phase (yO) containing aromatic hydrocarbons and removing the aqueous phase (yW) to obtain the organic phase (yO),
The method for producing bisphenol according to <1> above, wherein the solution (E) used in the step (A3) is the organic phase (yO).
<3> Having a step (x1) and a step (x2) between the step (A1) and the step (A2),
In the step (A1), a reaction is carried out in a reaction liquid (L1) containing an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, and a ketone or aldehyde, and the bisphenol produced is precipitated, and the bisphenol is dispersed. A step of obtaining a slurry reaction product liquid (S1),
The step (x1) is a step of removing the aqueous phase (xW) from the slurry reaction product liquid (S1) to obtain an organic phase (xO) containing an aromatic hydrocarbon in which bisphenol is dissolved,
The step (x2) is a step of cooling the organic phase (xO) and precipitating bisphenol to obtain a slurry solution (S2) in which bisphenol is dispersed,
The method for producing bisphenol according to <1> above, wherein the slurry solution (S) used in the step (A2) is the slurry solution (S2).
<4> The above <1> to <3>, wherein the basic compound is any one or more basic compounds selected from the group consisting of sodium hydrogen carbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide. Any method for producing bisphenol.
<5> The method for producing bisphenol according to any one of <1> to <4>, wherein the acid catalyst is sulfuric acid.
<6> The method for producing bisphenol according to any one of <1> to <5>, wherein the aromatic hydrocarbon is toluene.
<7> The above <1> to <6>, wherein the bisphenol is 2,2-bis(4-hydroxy-3-methylphenyl)propane or 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane. The method for producing bisphenol according to any one of the above.
<8> A method for producing a polycarbonate resin using bisphenol produced by the method for producing bisphenol according to any one of <1> to <7>.

According to the method for producing bisphenol of the present invention, high-quality bisphenol can be produced by reusing the recovered organic solvent while improving the recovery rate of the used organic solvent.
Moreover, polycarbonate resin can be manufactured using the obtained bisphenol.

1 is a flowchart showing the method for producing bisphenol of the present invention. 1 is a flowchart showing the method for producing bisphenol of the present invention. It is a flowchart which shows the manufacturing method (I) of bisphenol. It is a flowchart which shows the manufacturing method (II) of bisphenol. It is a flowchart which shows the manufacturing method (III) of bisphenol.

The embodiments of the present invention will be described in detail below, but the explanation of the constituent elements described below is an example of the embodiment of the present invention, and the present invention will not exceed the gist thereof. It is not limited to. Note that when the expression "~" is used in this specification, it is used as an expression that includes numerical values or physical property values before and after it.

[Method for producing bisphenol]
The present invention provides a method for producing bisphenol, which includes the following steps (A1) to (A4). (Hereinafter, it may be referred to as "the method for producing bisphenol of the present invention.").

Step (A1): In the presence of an acid catalyst, an aromatic alcohol is reacted with a ketone or an aldehyde to produce bisphenol. Step (A2): The bisphenol obtained in the step (A1) reacts with an aromatic hydrocarbon. Solid-liquid separation of a slurry solution (S) dispersed in a solvent containing the bisphenol-containing solid content (C) and the aromatic hydrocarbon-containing solution (e) Step (A3): Distilling the distillation raw material (D), which is a mixture of a solution (E) containing at least a part of the solution (e) containing aromatic hydrocarbons and a basic compound, to recover an aromatic hydrocarbon recovery solvent (R). Step (A4): Washing the bisphenol-containing solid content (C) using a washing solvent containing the recovery solvent (R) to obtain bisphenol.

In the method for producing bisphenol of the present invention, aromatic hydrocarbons used in reaction and purification are reused as part of the aromatic hydrocarbons used for washing bisphenol.
Since bisphenol is difficult to dissolve in aromatic hydrocarbons, using aromatic hydrocarbons for cleaning bisphenol has the advantage of reducing loss of bisphenol.
In addition, in step (A3), after mixing the solution (E) containing aromatic hydrocarbons and a basic compound, the aromatic hydrocarbons are distilled and recovered, so that polymerization inhibitors are contained in the recovered solvent (R). Contamination is suppressed, and even if bisphenol is washed using the aromatic hydrocarbon recovery solvent (R) in step (A4), a decrease in the polymerization activity of the obtained bisphenol is suppressed. The recovery rate of the recovery solvent (R) is also improved.

FIG. 1 is a flowchart showing the method for producing bisphenol of the present invention. Hereinafter, each step of the method for producing bisphenol of the present invention will be explained separately.

<Step (A1)>
Step (A1) is a step of reacting an aromatic alcohol with a ketone or aldehyde in the presence of an acid catalyst to produce bisphenol.

(aromatic alcohol)
The aromatic alcohol used in the method for producing bisphenol of the present invention is usually a compound represented by the following general formula (1).

Examples of the substituents for R ¹ to R ⁴ include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an amino group, and the like. Note that the alkyl group, alkoxy group, aryl group, etc. may be substituted or unsubstituted. The number of carbon atoms in the alkyl group or alkoxy group is 1 or more, and the upper limit thereof is preferably 12 or less, more preferably 8 or less, and still more preferably 6 or less. The number of carbon atoms in the aryl group is 6 or more, and the upper limit thereof is preferably 12 or less, more preferably 8 or less.

For example, the substituents for R ¹ to R ⁴ include hydrogen atom, fluoro group, chloro group, bromo group, iodo group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i- Butyl group, t-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n- Dodecyl group, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, t-butoxy group, n-pentyloxy group, i-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group group, cycloheptyl group, cyclooctyl group, cyclododecyl group, benzyl group, phenyl group, tolyl group, 2,6-dimethylphenyl group and the like.

Since R ² and R ³ are sterically bulky, it is difficult for the condensation reaction to proceed, so it is preferable that R 2 and R 3 are hydrogen atoms. Further, R ¹ to R ⁴ are each independently preferably a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or an amino group, and more preferably a hydrogen atom or an alkyl group. Examples include compounds in which R ¹ and R ⁴ are each independently a hydrogen atom or an alkyl group, and R ² and R ³ are hydrogen atoms.

Specifically, the compounds represented by the above general formula (1) include phenol, methylphenol (cresol), dimethylphenol (xylenol), ethylphenol, propylphenol, butylphenol, methoxyphenol, ethoxyphenol, propoxyphenol, Examples include butoxyphenol, aminophenol, benzylphenyl, phenylphenol, and the like.

Among these, one selected from the group consisting of phenol, methylphenol and dimethylphenol is preferred, methylphenol or dimethylphenol is more preferred, and methylphenol is even more preferred.

(ketone or aldehyde)
The ketone or aldehyde used in the method for producing bisphenol of the present invention is usually a compound represented by the following general formula (2).

Examples of substituents for R ⁵ and R ⁶ include a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and the like. Note that the alkyl group, alkoxy group, aryl group, etc. may be substituted or unsubstituted. The number of carbon atoms in the alkyl group or alkoxy group is 1 or more, and the upper limit thereof is preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the aryl group is 6 or more, and the upper limit thereof is preferably 12 or less, more preferably 8 or less.

For example, as substituents for R ⁵ and R ⁶ , hydrogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group , i-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, methoxy group , ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, t-butoxy group, n-pentyloxy group, i-pentyloxy group, n-hexyloxy group, n-heptyl Oxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group group, cyclooctyl group, cyclododecyl group, benzyl group, phenyl group, tolyl group, 2,6-dimethylphenyl group, and the like.

R ⁵ and R ⁶ may be bonded or cross-linked to each other between the two groups. R ⁵ and R ⁶ may be bonded together with adjacent carbon atoms to form a cycloalkylidene group.
For example, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, 3,3,5-trimethylcyclohexylidene, cycloheptylidene, cyclooctylidene, cyclononylidene, cyclodecylidene, cycloundecylidene, cyclo Examples include dodecylidene, fluorenylidene, xantonylidene, and thioxantonylidene.

Preferably, R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group, an aryl group, or a cycloalkylidene group formed by bonding R ⁵ and R ⁶ together with adjacent carbon atoms. . Examples include compounds in which R ⁵ and R ⁶ are each independently an alkyl group or a cycloalkylidene group formed by bonding R ⁵ and R ⁶ together with adjacent carbon atoms.

Specifically, the compounds represented by the general formula (2) include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentanaldehyde, hexanaldehyde, heptaldehyde, octanaldehyde, nonanaldehyde, decanaldehyde, undecanaldehyde, and dodecanaldehyde. Aldehydes such as acetone, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone, undecanone, dodecanone and other ketones; benzaldehyde, phenylmethyl ketone, phenylethyl ketone, phenylpropyl ketone, cresyl methyl ketone, cresyl Aryl alkyl ketones such as ethyl ketone, cresyl propyl ketone, xylyl methyl ketone, xyl ethyl ketone, xylyl propyl ketone; cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclononanone , cyclic alkane ketones such as cyclodecanone, cycloundecanone, and cyclododecanone; heterocyclic ketones such as fluorenone, xanthone, and thioxanthone.

When the amount of ketone or aldehyde is large relative to the aromatic alcohol as a raw material, the amount of ketone or aldehyde tends to increase, and when it is small, the aromatic alcohol is unreacted and is lost. For these reasons, the lower limit of the molar ratio of aromatic alcohol to ketone or aldehyde ((number of moles of aromatic alcohol/number of moles of ketone) or (number of moles of aromatic alcohol/number of moles of aldehyde)) is preferably It is 1.5 or more, more preferably 1.6 or more, even more preferably 1.7 or more. Further, the upper limit thereof is preferably 15 or less, more preferably 10 or less, still more preferably 8 or less.

(acid catalyst)
The acid catalyst in the method for producing bisphenol of the present invention includes sulfuric acid, hydrochloric acid, hydrogen chloride gas, hydrochloric acid, aromatic sulfonic acids such as p-toluenesulfonic acid, aliphatic sulfonic acids such as methanesulfonic acid, and strong acids such as phosphoric acid. can be used.

If the molar ratio of the acid catalyst to the raw material ketone or aldehyde ((number of moles of acid catalyst/number of moles of ketone) or (number of moles of acid catalyst/number of moles of aldehyde)) is small, it will change as the condensation reaction progresses. The acid catalyst is diluted by the water produced as a by-product, and the reaction takes time. Furthermore, if the amount is too high, the ketone or aldehyde may increase in quantity. For these reasons, the molar ratio of the acid catalyst to the raw material ketone or aldehyde is preferably 0.01 or more, more preferably 0.05 or more, and still more preferably 0.1 or more. Further, the upper limit thereof is preferably 10 or less, more preferably 8 or less, still more preferably 5 or less.

Among these, the acid catalyst is preferably one or more selected from the group consisting of sulfuric acid, hydrogen chloride gas, hydrochloric acid, aromatic sulfonic acid, and aliphatic sulfonic acid. In the condensation reaction between aromatic alcohols and ketones or aldehydes, phosphoric acid has low reactivity and is difficult to precipitate bisphenol, making it difficult to conduct the condensation reaction in a slurry state, resulting in a decrease in the yield and quality of bisphenol. It tends to be easy. More preferably, it is one or more selected from the group consisting of sulfuric acid, hydrogen chloride gas, and hydrochloric acid, and still more preferably sulfuric acid and/or hydrogen chloride gas. Sulfuric acid is particularly preferable as the acid catalyst from the viewpoints of excellent reaction efficiency, non-volatility of the catalyst, and less burden on equipment.

Sulfuric acid is an acidic liquid with the chemical formula H ₂ SO ₄ . Generally, sulfuric acid is used as an aqueous sulfuric acid solution diluted with water, and depending on its concentration, it is called concentrated sulfuric acid or diluted sulfuric acid. For example, dilute sulfuric acid is an aqueous sulfuric acid solution having a mass concentration of less than 50% by mass.

If the concentration of sulfuric acid used (the concentration of H ₂ SO ₄ in the sulfuric acid aqueous solution (H ₂ SO ₄ + H ₂ O)) is low, the amount of water will increase, making it difficult for the bisphenol production reaction to proceed, making it difficult to produce bisphenol. This increases the reaction time and makes it difficult to efficiently produce bisphenol. Therefore, the concentration of sulfuric acid used is preferably 70% by mass or more, more preferably 75% by mass or more, and still more preferably 80% by mass or more. Further, the upper limit of the concentration of sulfuric acid used is usually 99.5% by mass or less or 99% by mass or less.

(thiol promoter)
In the reaction of condensing an aromatic alcohol with a ketone or aldehyde, a thiol cocatalyst can be used as a cocatalyst. Examples of the thiol promoter include mercaptocarboxylic acids such as mercaptoacetic acid, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and 4-mercaptobutyric acid, methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, and pentyl mercaptan. Mercaptan, hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan (decane thiol), undecyl mercaptan (undecane thiol), dodecyl mercaptan (dodecane thiol), tridecyl mercaptan, tetradecyl mercaptan, pentadecyl mercaptan, Examples include mercaptophenol.

The molar ratio of thiol cocatalyst to ketone or aldehyde ((moles of thiol cocatalyst/moles of ketone) or (moles of thiol cocatalyst/moles of aldehyde)) is lower due to the use of thiol cocatalyst. The effect of improving bisphenol selectivity cannot be obtained, and if the amount is too high, it may mix with bisphenol and deteriorate the quality. For these reasons, the lower limit of the molar ratio of the thiol promoter to the ketone or aldehyde is preferably 0.001 or more, more preferably 0.005 or more, and still more preferably 0.01 or more. Further, the upper limit thereof is preferably 1 or less, more preferably 0.5 or less, still more preferably 0.1 or less.

(organic solvent)
The reaction to produce bisphenol can be carried out in the presence of an organic solvent. Examples of organic solvents include aromatic hydrocarbons, aliphatic alcohols, and aliphatic hydrocarbons. These solvents may contain one or more types. For example, a mixed solvent of an aromatic hydrocarbon and an aliphatic alcohol may be used.

Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, and mesitylene.

Examples of aliphatic hydrocarbons include hexane, heptane, octane, nonane, decane, undecane, and dodecane.

Examples of the aliphatic alcohol include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, n-pentanol, i-pentanol, n-hexanol, n-heptanol, Examples include monohydric alkyl alcohols such as n-octanol, n-nonanol, n-decanol, n-undecanol, and n-dodecanol; and polyhydric alcohols such as ethylene glycol, diethylene glycol, and triethylene glycol.
From the viewpoint of reaction efficiency, etc., the aliphatic alcohol is preferably a monovalent alkyl alcohol having 1 to 12 carbon atoms, more preferably a monovalent alkyl alcohol having 1 to 8 carbon atoms.

Note that a large amount of aromatic alcohol as a raw material may be used in place of the organic solvent. In this case, unreacted aromatic alcohol is lost, but the loss can be reduced by recovering and refining it by distillation or the like and reusing it.

When using an organic solvent, if the mass ratio of the organic solvent to the starting material ketone or aldehyde ((mass of organic solvent/mass of ketone) or (mass of organic solvent/mass of aldehyde)) is too large, the ketone or aldehyde and aromatic alcohols are difficult to react with, and the reaction takes a long time. If the amount is too small, the generated bisphenol may cause poor mixing, or the amount of ketone or aldehyde may be increased. For these reasons, the mass ratio of the organic solvent to the ketone or aldehyde is preferably 0.5 or more, more preferably 1 or more. Further, the upper limit may be adjusted depending on the type of organic solvent within a range in which bisphenol precipitation occurs, and may be 100 or less, 50 or less, or 30 or less.
In addition, as described later, the organic solvent may be supplied in divided portions, and when supplied in divided portions, the total amount of organic solvent used for preparing the reaction solution with respect to the ketone or aldehyde must be within the above range. It is preferable that there be.

The generated bisphenol is easily precipitated, and the loss when recovering bisphenol from the reaction solution after the reaction is completed (for example, loss to the filtrate during crystallization) can be reduced. Preferably, a solvent is used.

The organic solvent used in the production of bisphenol can be recovered and purified by distillation or the like and then reused. When reusing an organic solvent, an organic solvent with a low boiling point is preferred, specifically preferably 200°C or lower, more preferably 170°C or lower.

As described above, the method for producing bisphenol of the present invention reuses aromatic hydrocarbons used in reaction and purification as part of the aromatic hydrocarbons used for washing bisphenol. When aromatic hydrocarbons are not used as extraction solvents or washing solvents during purification, it is essential to use aromatic hydrocarbons during the reaction.

When aromatic hydrocarbons are used as extraction solvents or cleaning solvents during purification, it is not essential to use aromatic hydrocarbons during the reaction, but it is better to use aromatic hydrocarbons as an organic solvent during the reaction, which allows for reuse. This is preferable because the amount of aromatic hydrocarbons increases. Aromatic hydrocarbons have low solubility in bisphenol at room temperature, and bisphenol produced tends to precipitate, resulting in loss when recovering bisphenol from the reaction solution after completion of the reaction (for example, loss to the filtrate during crystallization). It is also preferable because it can reduce the

Therefore, the reaction between the aromatic alcohol and the ketone or aldehyde is preferably carried out in the presence of an organic solvent containing an aromatic hydrocarbon as a main component. Specifically, the organic solvent used in the reaction preferably contains aromatic hydrocarbons in an amount of 55% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more.
Among aromatic hydrocarbons, those with a boiling point of 200°C or lower are preferred, and those with a boiling point of 170°C or lower are more preferred. From the viewpoint of bisphenol solubility and boiling point, toluene is particularly preferred.

In the condensation reaction between an aromatic alcohol and a ketone or aldehyde, there is no particular restriction on the order in which various raw materials are mixed. It is preferable to do so. The solution containing the ketone or aldehyde can be supplied in bulk or in parts, but since the reaction that produces bisphenol is an exothermic reaction, it may be added dropwise little by little. A method of dividing and supplying, such as supplying, is preferable.

The solution containing an aromatic alcohol and an acid catalyst may consist of an aromatic alcohol and an acid catalyst, or may contain other components. For example, it may be a solution containing an aromatic alcohol, an acid catalyst, and an organic solvent.

Further, the solution containing a ketone or an aldehyde may consist of a ketone or an aldehyde, or may contain other components. For example, when using a thiol co-catalyst, it is preferable to mix the thiol co-catalyst with the ketone or aldehyde in advance and then use it for the reaction. As for the method of mixing the thiol co-catalyst and the ketone or aldehyde, the ketone or aldehyde may be supplied to the thiol co-catalyst, or the thiol co-catalyst may be supplied to the ketone or aldehyde. Further, the solution containing the ketone or aldehyde may also contain an organic solvent.

Further, when an organic solvent is used, the organic solvent may be mixed separately into a solution containing an aromatic alcohol and an acid catalyst and a solution containing a ketone or aldehyde.

If the reaction temperature is too low, the condensation reaction will be difficult to proceed, so it is preferably -30°C or higher, more preferably -20°C or higher, -15°C or higher, -5°C or higher, and 0°C or higher in this order. In addition, if the reaction temperature is too high, the self-condensation reaction of acetone or ketone, which is a side reaction, will proceed, and when a thiol, which is a co-catalyst, is used, the oxidative decomposition of thiol will tend to proceed, so it is preferably 50°C. or less, more preferably 45°C or less, still more preferably 40°C or less.

In the method for producing bisphenol of the present invention, the reaction time of the condensation reaction is appropriately adjusted depending on the reaction conditions such as the type of bisphenol to be produced, the reaction temperature, and the production scale, but is usually 500 hours or less, and 400 hours or less. It may be less than 350 hours or less than 350 hours. If the heating time is too long, the bisphenol produced will decompose, so the heating time is preferably within 30 hours, more preferably within 25 hours, and even more preferably within 20 hours. Further, the lower limit of the reaction time is usually 0.5 hours or more, preferably 1 hour or more, and more preferably 1.5 hours or more.

Note that the condensation reaction occurs when the aromatic alcohol comes into contact with the ketone or aldehyde under an acid catalyst, so the starting point of the reaction time is the point at which the contact between the aromatic alcohol and the ketone or aldehyde begins under the acid catalyst. (the point at which the condensation reaction starts). For example, when a ketone or aldehyde is supplied to a mixed solution of an aromatic alcohol and an acid catalyst over a period of 1 hour and then reacted for 1 hour, the reaction time is 2 hours.

Further, the reaction can be stopped by reducing the concentration of the acid catalyst, for example, by adding water or a base in an amount equivalent to or more than the acid catalyst used.

(bisphenol)
The bisphenol produced by the bisphenol production method of the present invention is usually a compound represented by the following general formula (3).

In general formula (3), R ¹ to R ⁴ have the same meanings as R ¹ to R ⁴ in general formula (1) above, and R ⁵ and R ⁶ represent R ⁵ in general formula (2) above, It has the same meaning as in R ⁶ .

Specifically, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethyl phenyl)propane, 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 3,3-bis(4-hydroxyphenyl)pentane , 3,3-bis(4-hydroxy-3-methylphenyl)pentane, 2,2-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxy-3-methylphenyl)pentane, 3, 3-bis(4-hydroxyphenyl)heptane, 3,3-bis(4-hydroxy-3-methylphenyl)heptane, 2,2-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxy Examples include, but are not limited to, -3-methylphenyl)heptane, 4,4-bis(4-hydroxyphenyl)heptane, 4,4-bis(4-hydroxy-3-methylphenyl)heptane, etc. isn't it.

Among these, preferred bisphenols produced by the bisphenol production method of the present invention are 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5- 2,2-bis(4-hydroxy-3-methylphenyl)propane, and 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, more preferably 2,2-bis(4-hydroxy-3-methylphenyl)propane. -methylphenyl)propane or 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane.

<Step (A2)>
In step (A2), the slurry solution (S) in which bisphenol obtained in step (A1) is dispersed in a solvent containing aromatic hydrocarbons is subjected to solid-liquid separation, and the solid content (C) containing bisphenol and the aromatic carbonization are separated. This is a step of obtaining a solution (e) containing hydrogen.

The slurry solution (S) is a slurry-like solution in which the bisphenol obtained in step (A1) is dispersed in a solvent containing an aromatic hydrocarbon. For example, as the slurry solution (S), although it depends on the reaction conditions, the slurry reaction product liquid obtained in step (A1) (for example, the slurry reaction product liquid (S1) in FIGS. 3 and 4) can be mentioned. . In addition, since the reaction product liquid after step (A1) contains water produced by the acid catalyst and condensation reaction, removal of the aqueous phase and crystallization are performed between step (A1) and step (A2). , a slurry solution (S) may be prepared (for example, slurry solution (S2) in FIG. 5).

As mentioned above, the slurry solution (S) is one in which the bisphenol (solid bisphenol) obtained in step (A1) is dispersed in a solvent (liquid component) containing an aromatic hydrocarbon, and the resulting solution (e ) (liquid component) contains aromatic hydrocarbons.
Moreover, the obtained solid content (C) contains bisphenol. Note that the obtained solid content (C) may include a part of the liquid component, but the liquid content is usually 50% by mass or less.

Examples of solid-liquid separation methods include filtration, centrifugation, and decantation.

<Step (A3)>
Step (A3) is distilling the distillation raw material (D), which is a mixture of a basic compound and a solution (E) containing at least a part of the solution (e) containing aromatic hydrocarbons, to recover aromatic hydrocarbons. This is a step of recovering the solvent (R).

(Preparation of distillation raw material (D))
The distillation raw material (D) to be distilled is a mixture of a solution (E) containing at least a part of the solution (e) containing aromatic hydrocarbons and a basic compound.
By performing distillation after mixing the solution (E) and the basic compound, it is possible to suppress the polymerization-inhibiting component contained in the solution (E) from being mixed into the aromatic hydrocarbon recovery solvent (R).

Solution (E) contains at least a part of solution (e), which is the liquid component separated in step (A2), and contains aromatic hydrocarbons. Solution (e) may be used as solution (E) as it is (for example, solution (e2) in Figure 5), or if solution (e) is a two-phase system of water and an organic solvent, it may be used as an organic solution with the aqueous phase removed. A phase (for example, the organic phase (yO1) in FIG. 3 or the organic phase (yO2) in FIG. 4) may be a solution (E).
Further, as shown in FIG. 2, the solution (E) may be the solution (e) plus the waste liquid discharged in step (A4).

The basic compound used may generally be a basic compound, such as inorganic salts such as sodium hydrogen carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, pyrrolidine, pyridine, diazabicycloundecene, etc. , N-methyl-2-pyrrolidone, 1,8-bis(dimethylamino)naphthalene, and other nitrogen-containing organic compounds.
From the viewpoint of easy availability and low cost, it is particularly preferable to use at least one selected from the group consisting of sodium hydrogen carbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide.

These basic compounds may be used alone or in combination. Further, these basic compounds may be dissolved in water and supplied as an aqueous solution, or may be supplied as a solid.

The basic compound may be added in an equal amount to the polymerization activity inhibiting component contained in the solution (E). However, since it is difficult to accurately know the content of the polymerization activity-inhibiting component, it may be adjusted to an excess amount, and the mass ratio of the basic compound to the solution (E) is preferably 1 mass ppb or more. 2 mass ppb or more is more preferable, and 3 mass ppb or more is particularly preferable. The mass ratio of the basic compound to the solution (E) may be 0.1 ppm or more, 1 ppm or more, 0.01 mass% or more, or 0.05 mass% or more. If the amount of the basic compound added is too large, the recovery rate of the recovery solvent (R) will decrease, and the basic compound added in excess will cause economic loss, so the mass of the basic compound relative to the solution (E) The ratio can be 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, etc.

The mixing temperature of the solution (E) and the basic compound is preferably 0°C or higher, more preferably 5°C or higher, in order for the basic compound to efficiently react with and neutralize the acidic component that serves as a polymerization-inhibiting component. More preferably, the temperature is 10°C or higher. Further, in order to efficiently evaporate the recovered solvent (R), the temperature is preferably 250°C or lower, more preferably 240°C or lower, and even more preferably 230°C or lower.
The mixing time of the solution (E) and the basic compound is preferably 0.1 hour or more, more preferably 0.2 hour or more, in order for the basic compound to efficiently react with the polymerization activity inhibiting component and neutralize it. , more preferably 0.3 hours or more. Further, in order to recover the recovered solvent (R) economically, the time is preferably 200 hours or less, more preferably 190 hours or less, and even more preferably 180 hours or less.

(distillation)
In the method for producing bisphenol of the present invention, the aromatic hydrocarbon used as the organic solvent during the reaction or the extraction solvent during purification can be recovered by a conventional method. For example, the distillation raw material (D) is placed in a distillation apparatus, heated, and ketones or aldehydes with low boiling points and water are fractionated to obtain a highly pure aromatic hydrocarbon recovery solvent (R). Further, the distillation operation may be carried out under reduced pressure.
Although the temperature and reduced pressure conditions during distillation depend on the type of aromatic hydrocarbon, for example, distillation can be carried out at 70 to 120° C. and under reduced pressure of 200 to 800 hpa.
The distillation recovery rate (mass of distillate/mass of solution (E) x 100 (%)) is preferably 50% by mass or more, more preferably 60% by mass or more, 70% by mass or more, and 75% by mass in that order. Further, the upper limit can be set to 95% by mass or less, 90% by mass or less, 85% by mass or less, etc., taking into consideration the purity of the aromatic hydrocarbon recovery solvent (R).

(Aromatic hydrocarbon recovery solvent (R))
If the purity of the recovery solvent (R) for aromatic hydrocarbons is low (mass of aromatic hydrocarbons/mass of recovery solvent (R) x 100 (%)), when reused as a cleaning solvent, the resulting bisphenol will be Since quality is deteriorated, the content is preferably 80% by mass or more, more preferably 85% by mass or more, particularly preferably 90% by mass or more.

<Step (A4)>
Step (A4) is a step of washing the solid content (C) containing bisphenol using a washing solvent containing the recovery solvent (R) to obtain bisphenol.

Specifically, the solid content (C) containing bisphenol is added to a washing solvent and then filtered or centrifuged, or the solid content (C) containing bisphenol is suspended in a washing solvent and then filtered, centrifuged or decanted. Examples include methods of

The cleaning solvent may be any solvent as long as it contains the recovery solvent (R), and the recovery solvent (R) may be used as the cleaning solvent. In addition, the cleaning solvent may contain other than the recovery solvent (R), but it is preferable that the main component is aromatic hydrocarbons (80% by mass or more, 85% by mass or more, 90% by mass or more). A mixture of the solvent (R) and an unused aromatic hydrocarbon may be used as the cleaning solvent. The solid content (C) can be washed multiple times, and may be washed multiple times with the same cleaning solvent or multiple times with different cleaning solvents.

In order to improve the cleaning effect, the amount of cleaning solvent used relative to the solid content (C) containing bisphenol (mass of cleaning solvent/mass of solid content (C) containing bisphenol) is preferably 0.01 or more, and 0.01 or more. More preferably 1 or more. Furthermore, if the amount of cleaning solvent used exceeds a certain amount, the cleaning effect tends to be saturated, resulting in inefficiency. Therefore, the amount of the cleaning solvent used relative to the solid content (C) containing bisphenol is preferably 20 or less, more preferably 10 or less.

The method for producing bisphenol of the present invention may include steps other than steps (A1) to (A4). For example, it may include a step of drying the bisphenol obtained in step (A4). The drying method may be reduced pressure drying or drying at normal pressure. The drying temperature can be determined as appropriate, and for example, drying can be performed at 50 to 120° C. for 2 to 15 hours.

Moreover, as mentioned above, between the step (A1) and the step (A2), there may be a step of preparing the slurry solution (S), and between the step (A2) and the step (A3), The method may include a step of preparing a solution (E). For example, when solution (e) is a two-phase system of water and an organic solvent, solution (e1-1) or a mixed solution (e1-2) of solution (e1-1) and a basic aqueous solution is added to the aqueous phase (e1-2). yW) and an organic phase (yO) containing an aromatic hydrocarbon, and the step (y) of removing the aqueous phase (yW) to obtain the organic phase (yO) may be included.

Furthermore, the obtained bisphenol can be further purified by simple means such as crystallization or column chromatography.

<Applications of bisphenol>
Bisphenol obtained by the bisphenol production method of the present invention can be used as polyether resin, polyester resin, polyarylate, etc., which is used for various purposes such as optical materials, recording materials, insulating materials, transparent materials, electronic materials, adhesive materials, and heat-resistant materials. Components and curing agents for various thermoplastic resins such as resins, polycarbonate resins, polyurethane resins, and acrylic resins, and various thermosetting resins such as epoxy resins, unsaturated polyester resins, phenol resins, polybenzoxazine resins, and cyanate resins. , additives or their precursors. It is also useful as an additive for color developers, anti-fading agents, bactericides, antibacterial and antifungal agents, etc. for heat-sensitive recording materials.

Among these, it is preferable to use it as a raw material (monomer) for thermoplastic resins and thermosetting resins because it can impart good mechanical properties, and among them, it is more preferable to use it as a raw material for polycarbonate resins and epoxy resins. It is also preferable to use it as a color developer, and it is particularly preferable to use it in combination with a leuco dye and a color change temperature regulator.

Next, an example of the method for producing bisphenol of the present invention will be specifically explained based on the drawings. 3 to 5 are diagrams showing an example of the method for producing bisphenol of the present invention.

<Method for producing bisphenol (I)>
The method for producing bisphenol (I) shown in FIG. This is a method for producing bisphenol having the following.

In the step (A1-1), a reaction is carried out in a reaction liquid (L1) containing an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, and a ketone or aldehyde, the bisphenol produced is precipitated, and the bisphenol is dispersed. This is a step of obtaining a slurry reaction product liquid (S1), and is one of the embodiments of step (A1).
Step (A2-1) is a step of performing solid-liquid separation of the slurry reaction product liquid (S1) to obtain a solid content (C1) containing bisphenol and a solution (e1-1) containing aromatic hydrocarbons, This is one aspect of step (A2).
Step (y1) is a step in which the solution (e1-1) is separated into an aqueous phase (yW1) and an organic phase (yO1), the aqueous phase (yW1) is removed, and the organic phase (yO1) is obtained. This is one of the aspects of (y).
Step (A3-1a) is a step of distilling a distillation raw material (D1a) in which an organic phase (yO1) and a basic compound are mixed to recover an aromatic hydrocarbon recovery solvent (R1a); This is one of the embodiments of (A3).
Step (A4-1a) is a step of washing the solid content (C1) containing bisphenol using a washing solvent containing the recovery solvent (R1a) to obtain bisphenol, and is one of the embodiments of step (A4). .

The method for producing bisphenol (I) is an example having a step (step (y)) of preparing a solution (E) containing an aromatic hydrocarbon between step (A2) and step (A3).
In the method (I) for producing bisphenol, the slurry reaction product liquid (S1) obtained in step (A1-1) is used as it is as the slurry solution (S) in step (A2), and the solution (E ), the organic phase (yO1) obtained in step (y1) is used.

The slurry reaction product liquid (S1) obtained in step (A1-1) contains an acid catalyst and water produced by the condensation reaction, and the slurry reaction product liquid (S1) is converted into a solid liquid in step (A2-1). The solution (e1-1) obtained by separation contains an acid catalyst and water in addition to aromatic hydrocarbons. In the method for producing bisphenol (I), in step (y1), the aqueous phase (yW1) is removed from the solution (e1-1), and then in step (A3-1a), aromatic hydrocarbons are distilled. to recover.
Generally, the solution (e1-1) to be solid-liquid separated in step (A2-1) is allowed to stand still, so that the aqueous phase (yW1) and the organic phase (yO1) are separated, with the aqueous phase (yW1) as the lower phase. Separate into two parts. Therefore, the aqueous phase (yW1) can be extracted from the bottom of the reaction vessel.

The methods of step (A1-1), step (A2-1), step (A3-1a) and step (A4-1a) include step (A1), step (A2), step (A3) and step (A4), respectively. ).

In addition, as described in the above step (A1), the reaction solution (L1) in step (A1-1) contains an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, a thiol cocatalyst, and a ketone or aldehyde. , organic solvents other than aromatic hydrocarbons such as aliphatic alcohols.

Further, step (A2-1) may be a step of solid-liquid separation of a slurry-like diluted liquid obtained by diluting the slurry reaction product liquid (S1) with a diluent solvent (water, organic solvent, etc.).

<Method for producing bisphenol (II)>
The manufacturing method (II) for bisphenol shown in FIG. This is a method for producing bisphenol having the following.

Step (A1-1) and step (A2-1) are the same as the method for producing bisphenol (I).
Step (y2) is to separate the mixed solution (e1-2) of the solution (e1-1) and a basic aqueous solution into an aqueous phase (yW2) and an organic phase (yO2), and remove the aqueous phase (yW2). This is a step of obtaining an organic phase (yO2), and is one of the embodiments of step (y).
Step (A3-1b) is a step of distilling a distillation raw material (D1b) in which an organic phase (yO2) and a basic compound are mixed to recover an aromatic hydrocarbon recovery solvent (R1b). This is one of the embodiments of (A3).
Step (A4-1b) is a step of washing the solid content (C1) containing bisphenol using a washing solvent containing the recovery solvent (R1b) to obtain bisphenol, and is one of the embodiments of step (A4). .

The method for producing bisphenol (II) differs from the method for producing bisphenol (I) in that it includes step (y2) instead of step (y1).
In the bisphenol production method (II), the slurry reaction product liquid (S1) obtained in step (A1-1) is used as it is as the slurry solution (S) in step (A2), and the solution (E ), the organic phase (yO2) obtained in step (y2) is used.

As described above, the solution (e1-1) contains an acid catalyst and water in addition to aromatic hydrocarbons. In step (y2), the aqueous phase (yW2) is removed from the mixed solution (e1-2) of the solution (e1-1) and a basic aqueous solution to obtain an organic phase (yO2).
By allowing the solution (e1-2) to stand still, the aqueous phase (yW2) separates as a lower phase and can be extracted from the bottom of the reaction tank.
Examples of the basic aqueous solution to be mixed with the solution (e1-1) include an aqueous sodium hydrogen carbonate solution, an aqueous sodium carbonate solution, and an aqueous sodium hydroxide solution. When an excess basic aqueous solution is mixed with the solution (e1-1), a large amount of salt remains in the resulting organic phase (yO2), and the recovery rate of the recovered solvent (R1b) recovered by distillation in step (A3-1b) decreases. Therefore, it is preferable to mix the basic aqueous solution so that the pH of the aqueous phase (yW2) is approximately 7 to 12.

Note that the organic phase (yO2) may be further washed with water, etc., and then mixed with a basic compound to be used as a distillation raw material (D1b).
For example, an aqueous phase (yW2a) having a pH of 9 to 12 is removed from a solution (e1-2), which is a mixture of the solution (e1-1) and a basic aqueous solution, to obtain an organic phase (yO2a). Next, the organic phase (yO2a) is washed with water until the pH of the aqueous phase to be removed becomes 6.5 to 7.5, or until the electrical conductivity of the aqueous phase to be removed becomes 100 μS/cm or less. do. The organic phase (yO2a) after washing with water may be used in step (A3-1b).
Here, the pH of the aqueous phase can be measured at 25° C. using a pH meter “pH METER ES-73” manufactured by Horiba, Ltd. or the like. Further, the electrical conductivity of the aqueous phase can be measured at 25° C. using an electrical conductivity meter “COND METER D-71” manufactured by Horiba, Ltd.

The methods of step (A1-1), step (A2-1), step (A3-1b) and step (A4-1b) include step (A1), step (A2), step (A3) and step (A4), respectively. ).

In the bisphenol production methods (I) and (II), the reaction liquid (L1) in step (A1-1) is an example in which an organic solvent containing an aromatic hydrocarbon is used, but the slurry reaction product liquid ( When S1) is diluted with an aromatic hydrocarbon and subjected to solid-liquid separation, the reaction liquid (L1) does not need to contain aromatic hydrocarbons.
Furthermore, in order to obtain bisphenol with higher purity, it is preferable to perform crystallization and washing (suspension washing, etc.) after step (A4-1a) and step (A4-1b). The recovery solvent (R1a) in step (A3-1a) and the recovery solvent (R1b) in step (A3-1b) can also be used for this post-crystallization washing.

<Method for producing bisphenol (III)>
The method for producing bisphenol (III) shown in FIG. (A4-2) A method for producing bisphenol having (A4-2).

Step (A1-1) is the same as the bisphenol production method (I).
Step (x1) is a step of removing the aqueous phase (xW1) from the slurry reaction product liquid (S1) to obtain an organic phase (xO1) containing aromatic hydrocarbons in which bisphenol is dissolved.
Step (x2) is a step of cooling the organic phase (xO1) and precipitating bisphenol to obtain a slurry solution (S2) in which bisphenol is dispersed.
Step (A2-2) is a step of separating the slurry solution (S2) into solid and liquid to obtain a solid content (C2) containing bisphenol and a solution (e2) containing aromatic hydrocarbons, and step (A2) This is one of the aspects of
Step (A3-2) is a step of distilling the distillation raw material (D2), which is a mixture of the solution (e2) and a basic compound, to recover the aromatic hydrocarbon recovery solvent (R2), This is one of the aspects of A3).
Step (A4-2) is a step of washing the solid content (C2) containing bisphenol using a washing solvent containing the recovery solvent (R2) to obtain bisphenol, and is one of the embodiments of step (A4). .

The method for producing bisphenol (III) is an example having a step (x1), which is a step of preparing a slurry solution (S), and a step (x2) between the step (A1) and the step (A2).
By performing step (x1) and step (x2), highly pure bisphenol can be easily obtained.
In the method for producing bisphenol (III), the slurry solution (S2) obtained in step (x2) is used as the slurry solution (S) in step (A2). Further, the solution (e2) obtained in step (A2-2) is used as it is as solution (E) in step (A3).

(Step (x1))
Step (x1) can be a step of dissolving bisphenol in an organic solvent by heating, adding a good solvent, etc., and then removing the aqueous phase (xW1) to obtain the organic phase (xO1). Alternatively, after removing the aqueous phase (xW1), bisphenol may be dissolved in an organic solvent by heating, addition of a good solvent, etc. to obtain an organic phase (xO1).

Examples of methods for obtaining the organic phase (xO1) containing aromatic hydrocarbons in which bisphenol is dissolved include the following methods (i) to (iv).

・Method (i)
The slurry reaction product liquid (S1) obtained in step (A1-1) and a basic aqueous solution are heated and mixed to dissolve bisphenol. Next, after separating into an aqueous phase (xW1) and an organic phase (xO1), the aqueous phase (xW1) is removed to obtain an organic phase (xO1).

・Method (ii)
The slurry reaction product liquid (S1) obtained in step (A1-1), a basic aqueous solution, and an extraction solvent are heated and mixed to dissolve bisphenol. Next, after separating into an aqueous phase (xW1) and an organic phase (xO1), the aqueous phase (xW1) is removed to obtain an organic phase (xO1).

・Method (iii)
The slurry reaction product liquid (S1) obtained in step (A1-1) is separated into an aqueous phase (xW1) and a slurry-like organic phase (sO1) containing an aromatic hydrocarbon in which bisphenol is dispersed. (xW1) is removed. Next, the organic phase (sO1) is heated to dissolve bisphenol to obtain an organic phase (xO1) containing aromatic hydrocarbons in which bisphenol is dissolved.

・Method (iv)
A slurry-like diluted solution obtained by diluting the slurry reaction product liquid (S1) obtained in step (A1-1) with a diluting solvent is mixed with an aqueous phase (xW1) and a slurry-like organic solution containing an aromatic hydrocarbon in which bisphenol is dispersed. phase (sO1) and remove the aqueous phase (xW1). Next, the organic phase (sO1) is heated to dissolve bisphenol to obtain an organic phase (xO1) containing aromatic hydrocarbons in which bisphenol is dissolved.

Examples of the basic aqueous solution used in method (i) and method (ii) include aqueous sodium hydrogen carbonate solution, aqueous sodium carbonate solution, and aqueous sodium hydroxide solution.
The extraction solvent used in method (ii) includes organic solvents such as aromatic hydrocarbons.
Examples of the diluting solvent used in method (iv) include water such as ion-exchanged water, demineralized water, and distilled water, acidic to neutral aqueous solutions such as saline, and organic solvents such as aromatic hydrocarbons.
Here, the reaction solution (L1) in step (A1-1) is an example in which aromatic hydrocarbon water is used, but when aromatic hydrocarbons are used as the extraction solvent or dilution solvent in step (x1), The reaction solution (L1) in step (A1-1) may not contain aromatic hydrocarbons.

The heating temperature for dissolving bisphenol in methods (i) to (iv) is not particularly limited as long as it is a temperature at which bisphenol is dissolved, and it depends on the presence or absence of an organic solvent in the slurry organic phase, the type of organic solvent, etc. It will be determined as appropriate. Specifically, the temperature can be set to 50°C or higher or 60°C or higher. Further, if the heating temperature is too high, bisphenol will be easily decomposed, so it is preferably 100°C or lower or 90°C or lower.

The obtained organic phase (xO1) may be used in step (x2) after further washing with water or a basic aqueous solution. For example, the obtained organic phase (xO1) is washed with water or saline, and if necessary, neutralized and washed with aqueous sodium bicarbonate, etc., or the organic phase (xO1) is washed with aqueous sodium bicarbonate, etc. It can be washed with water or saline solution depending on the situation. The organic phase (xO1) is preferably washed repeatedly with water or a basic aqueous solution until the pH of the aqueous phase to be removed becomes 7 or higher.

For example, after washing with a basic aqueous solution so that the pH of the aqueous phase to be removed is 9 or higher, water or saline solution etc. are washed so that the pH of the aqueous phase to be removed is 6.5 to 7.5. It is preferable to further perform water washing using. Washing with a basic aqueous solution so that the aqueous phase to be removed becomes basic makes it difficult for polymerization inhibitors to be mixed into bisphenol, and also increases the recovery rate of the recovered solvent (R2) in step (A3-2). can be further improved. On the other hand, if the aqueous phase is strongly basic (high pH), bisphenol in the organic phase becomes bisphenol salt and moves to the aqueous phase, increasing the loss of bisphenol in the organic phase. is preferable, and 12 or less is more preferable.

(Step (x2))
Step (x2) is a step of cooling the organic phase (xO1) and precipitating bisphenol to obtain a slurry solution (S2) in which bisphenol is dispersed.
The cooling method is not particularly limited, but water cooling, air cooling, etc. can be used. In order to easily precipitate crystals and increase the purity of the precipitated crystals, seed crystals may be added. Seed crystals can be added at the start of cooling or during cooling. When using a large amount of aromatic alcohol, it can be carried out after removing excess aromatic alcohol by distillation before step (x2).

The cooling start temperature can be selected from the same temperature range as the heating temperature in step (x1). By cooling from the cooling start temperature to the cooling temperature, bisphenol is precipitated.

The cooling temperature is not particularly limited as long as it can be selected within a range where bisphenol precipitation occurs, but if the cooling temperature is too high, crystals will not precipitate sufficiently, so it is preferably 30°C or lower, more preferably 20°C or lower. Further, the cooling temperature can be appropriately selected from −30° C. or higher. For example, the temperature may be -20°C or higher, -15°C or higher, -5°C or higher, or 0°C or higher. Although it depends on the composition of the organic phase (xO1), if the cooling temperature is too low, the organic phase (xO1) tends to solidify, so it is preferably 5° C. or higher.

The cooling rate is usually about 0.1 to 1.5°C/min. If the cooling rate is too slow, it will take a long time for bisphenol to precipitate, and if the cooling rate is too fast, it will tend to crystallize while containing impurities. Preferably, the precipitation time is 1 to 10 hours.

In step (A3-2), the aromatic hydrocarbon-containing solution (e2) obtained by solid-liquid separation of the slurry solution (S2) is used as it is. The mass ratio of the basic compound to the solution (e2) can be arbitrarily selected from the range of 1 ppb to 20 mass %, but is preferably 0.01 mass % or more, more preferably 0.05 mass % or more. Further, it is preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less.

[Production method of polycarbonate resin]
A method for producing a polycarbonate resin using bisphenol obtained by the method for producing bisphenol of the present invention (hereinafter, sometimes referred to as "bisphenol of the present invention") as a raw material will be described. The polycarbonate resin obtained by the method for producing polycarbonate resin of the present invention is obtained by transesterifying the bisphenol of the present invention and a carbonic acid diester such as diphenyl carbonate in the presence of an alkali metal compound and/or an alkaline earth metal compound. It can be produced by a reaction method or the like. The above transesterification reaction can be carried out by appropriately selecting a known method, but an example using the bisphenol and diphenyl carbonate of the present invention as raw materials will be described below.

In the above method for producing a polycarbonate resin, it is preferable to use diphenyl carbonate in an excess amount relative to the bisphenol of the present invention. The amount of diphenyl carbonate used relative to the bisphenol is preferably large because the produced polycarbonate resin has few terminal hydroxyl groups and the polymer has excellent thermal stability. It is preferable that the amount is small in terms of ease of manufacturing the polycarbonate resin. For these reasons, the amount of diphenyl carbonate used per mol of bisphenol is usually 1.001 mol or more, preferably 1.002 mol or more, and usually 1.3 mol or less, preferably 1.2 mol or less. It is.

As for the raw material supply method, the bisphenol and diphenyl carbonate of the present invention can be supplied in solid form, but it is preferable to melt one or both of them and supply them in a liquid state.

When producing polycarbonate resin by transesterifying diphenyl carbonate and bisphenol, a transesterification catalyst is usually used. In the above method for producing polycarbonate resin, it is preferable to use an alkali metal compound and/or an alkaline earth metal compound as the transesterification catalyst. These may be used alone or in combination of two or more in any combination and ratio. Practically speaking, it is desirable to use an alkali metal compound.

The amount of catalyst used per mole of bisphenol or diphenyl carbonate is usually 0.05 μmol or more, preferably 0.08 μmol or more, more preferably 0.10 μmol or more, and usually 100 μmol or less, preferably It is 50 μmol or less, more preferably 20 μmol or less.

By using the amount of the catalyst within the above range, it is easy to obtain the polymerization activity necessary to produce a polycarbonate resin with a desired molecular weight, the polymer color is excellent, and excessive branching of the polymer does not proceed. Easy to obtain polycarbonate resin with excellent fluidity during molding.

In order to produce a polycarbonate resin by the above method, it is preferable to continuously supply both of the above raw materials to a raw material mixing tank, and to continuously supply the resulting mixture and transesterification catalyst to a polymerization tank.
In the production of polycarbonate resin by the transesterification method, both raw materials supplied to a raw material mixing tank are usually uniformly stirred and then supplied to a polymerization tank where a catalyst is added to produce a polymer.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

[Raw materials and reagents]
Reagents from Wako Pure Chemical Industries, Ltd. were used for orthocresol, acetone, toluene, sulfuric acid, dodecanethiol, methanol, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, cesium carbonate, and biphenyl. Diphenyl carbonate was manufactured by Mitsubishi Chemical Corporation.

[evaluation]
<Phenol production rate>
The production rate of phenol by the reaction between bisphenol C and diphenyl carbonate was measured by high performance liquid chromatography (hereinafter referred to as LC) under the following procedure and conditions.
・Analyzer: Shimadzu LC-2010A
Imtakt ScherzoSM-C18 3μm 250mm x 3.0mm ID
・Method: Isocratic method ・Analysis temperature: 40℃
・Eluent composition:
Solution A Ammonium acetate: Acetic acid: Dechlorinated water = 3.000 g: 1 mL: 1 L Solution B Solution Ammonium acetate: Acetic acid: Acetonitrile = 1.500 g: 1 mL: 900 mL Solution A: Solution B = 10:90 (volume ratio) )
・Analysis time: 20 minutes ・Flow rate 0.34 ml/min ・Detection wavelength was 254 nm.

The phenol production rate (initial polymerization activity) was calculated using the following formula.
Phenol production rate (initial polymerization activity) = LC area of phenol ÷ (LC area of phenol + LC area of diphenyl carbonate + LC area of bisphenol C) x 100 (%)
Note that the LC area refers to the area of a peak detected by high performance chromatography.

The greater the amount of components that inhibit the reaction of bisphenol C with diphenyl carbonate, the lower the phenol production rate, and the fewer the components that inhibit the reaction, the higher the phenol production rate. The calculated phenol production rate was evaluated based on the following criteria.
◎: Phenol production rate is 12.0 area% or more ○: Phenol production rate is 5.0 to 12.0 area%
△: Phenol production rate is 2.0 to 5.0 area%
×: Phenol production rate is 2.0 area% or less

<Evaluation of polymerization activity of bisphenol>
A polycarbonate resin was produced using the obtained bisphenol C, and the time from when the temperature was raised to 280°C until the end of polymerization (post-polymerization time) was evaluated as the polymerization activity of bisphenol. The polymerization activity of bisphenol was evaluated based on the following criteria.
○: 140 minutes or more and 200 minutes or less △: Less than 140 minutes or more than 200 minutes ×: Polymerization reaction does not proceed with the predetermined amount of polymerization catalyst

<Distillation recovery rate>
The distillation recovery rate of aromatic hydrocarbons in step (A3) was calculated using the following formula.
Distillation recovery rate (%) = Distilled amount [g] / Charge amount (mass of crystallization filtrate) [g] x 100 (%)

<Recycling rate>
The recyclable recovery rate of aromatic hydrocarbons in step (A3) was evaluated as the recycling rate as follows.
Polymerization activity evaluation 〇 or △: Recovery rate = Recycling rate Polymerization activity evaluation ×: Not recyclable = Recycling rate 0%

[Example 1]
(1-1) Production of bisphenol C <Step (A1)>
Put 280.0 g of toluene, 15.0 g of methanol, and 230.4 g of ortho-cresol under a nitrogen atmosphere into a separable flask equipped with a thermometer, dropping funnel, jacket, and squid-type stirring blade, and maintain the internal temperature below 10°C. While stirring, 95.0 g of 98% by mass sulfuric acid was added to prepare a mixed solution A. Next, 61.0 g of acetone (substance amount: 1.05 mol), 5.4 g of dodecanethiol, and 50.0 g of toluene were put into the dropping funnel to prepare a mixed solution B. While the mixed solution A was maintained at 10° C. or lower, the mixed solution B in the dropping funnel was added dropwise to the mixed solution A over 45 minutes while stirring. While the mixed liquid B was being dropped into the mixed liquid A, the produced bisphenol precipitated and became a slurry. Furthermore, the reaction solution was stirred for an additional 1 hour while maintaining the temperature at 10° C. to obtain a slurry-forming reaction solution.

<Step (x1)>
To the obtained slurry reaction product liquid, 120 g of 25% sodium hydroxide solution was added and stirred, the temperature was raised to 75° C., the bisphenol was dissolved, and the mixture was allowed to stand still to separate oil and water. After oil and water separation, the aqueous phase was removed from the bottom of the separable flask.
A 3% by weight sodium hydrogen carbonate solution was added to the obtained organic phase, and the mixture was stirred at 80°C to separate oil and water (pH of the aqueous phase was 9.2). After oil and water separation, the aqueous phase was removed from the bottom of the separable flask. 100 g of demineralized water was added to this organic phase and stirred at 80°C to separate oil and water. After oil and water separation, the aqueous phase was removed from the bottom of the separable flask. This operation was repeated three times to obtain 620 g of an organic phase in which bisphenol C was dissolved (pH of the final aqueous phase was 7.1).

<Step (x2)>
The organic phase in which bisphenol C was dissolved was gradually cooled from 80°C to 5°C to precipitate bisphenol C crystals to obtain a slurry solution.

<Step (A2)>
The resulting slurry solution containing bisphenol C crystals was subjected to solid-liquid separation using a centrifuge to obtain a bisphenol C cake and a crystallization filtrate.

The operations of step (A1), step (x1), step (x2), and step (A2) were repeated, and the obtained crystallization filtrate was mixed and used in step (A3). In addition, a bisphenol C cake was mixed in the same manner and used in step (A4).

<Step (A3)>
500.3 g of the crystallized filtrate obtained in step (A2) was added to a 1 L distillation flask equipped with a thermometer, a distillation tube with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, and sodium hydrogen carbonate. 1.0 g of (NaHCO ₃ ) was added and stirred for 90 minutes while maintaining the temperature at 40°C. Thereafter, the temperature was raised to 80°C, and while maintaining the temperature at 80°C and reducing the pressure to 647 hPa using a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 6.0% (distilled amount 29.9 g/charged amount 500.3 g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 77. It was evaporated to 4% (distilled amount: 387.2 g/charged amount: 500.3 g x 100) to obtain toluene recovery solvent 1.
The amount of sodium hydrogen carbonate added to the crystallization filtrate was 0.200% by mass (1.0g/500.3g×100).

<Step (A4)>
100 g of toluene recovery solvent 1 obtained in step (A3) was supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing was performed while loosening the bisphenol C cake, and a centrifuge was used. Solid-liquid separation was performed. This operation was repeated two more times to obtain a fine cake of bisphenol C.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 115 g of white bisphenol C.

(1-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (1-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 16.2 area % of phenol had been produced.

(1-3) Polymerization evaluation of bisphenol C 100.00 g (0.39 mol) of bisphenol C obtained in (1-1) was placed in a 150 mL glass reaction tank equipped with a stirrer and a distillation tube. , 86.49 g (0.4 mol) of diphenyl carbonate, and 479 μL of a 400 mass ppm cesium carbonate aqueous solution were added. The pressure of the glass reaction tank was reduced to about 100 Pa, and then the pressure was returned to atmospheric pressure with nitrogen, which was repeated three times to replace the inside of the reaction tank with nitrogen. Thereafter, the reaction tank was immersed in a 200°C oil bath to melt the contents.

The rotation speed of the stirrer was set to 100 times per minute, and the pressure in the reaction tank was reduced to absolute pressure over a period of 40 minutes while distilling off the phenol that was produced by the oligomerization reaction of bisphenol C and diphenyl carbonate in the reaction tank. The pressure was reduced from 101.3 kPa to 13.3 kPa. Subsequently, the pressure inside the reaction tank was maintained at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off the phenol. Thereafter, the external temperature of the reaction tank was raised to 250° C., and the pressure inside the reaction tank was reduced from 13.3 kPa to 399 Pa in absolute pressure over 40 minutes, and the distilled phenol was removed from the system.

Thereafter, the external temperature of the reaction tank was raised to 280° C., the absolute pressure of the reaction tank was reduced to 30 Pa, and a polycondensation reaction was carried out. The polycondensation reaction was terminated when the stirrer in the reaction tank reached a predetermined stirring power.
The time from when the temperature was raised to 280°C to when the polymerization was completed (second stage polymerization time) was 170 minutes.

[Example 2]
(2-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2) and step (A2) were performed to obtain a bisphenol C cake and crystallization filtrate. .

<Step (A3)>
504.3 g of the crystallized filtrate obtained in step (A2) was added to a 1 L distillation flask equipped with a thermometer, a distillation tube with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, and sodium hydrogen carbonate. Add 1.0 g of (NaHCO ₃ ), heat to 80° C. with stirring, and hold for 30 minutes. Thereafter, while reducing the pressure to 647 hPa with a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 7.1% (distillation amount 35.7g/charged amount 504.3g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 73. It was evaporated to 8% (distilled amount: 372.3 g/charged amount: 504.3 g x 100) to obtain toluene recovery solvent 2.
The amount of sodium hydrogen carbonate added to the crystallization filtrate was 0.198% by mass (1.0g/504.3g×100).

<Step (A4)>
100 g of toluene recovery solvent 2 obtained in step (A3) is supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing is performed while loosening the cake, and solid-liquid separation is performed using a centrifuge. I did it. This operation was repeated two more times to obtain a fine cake of bisphenol C.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 117 g of white bisphenol C.

(2-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (2-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 14.7 area % of phenol had been produced.

(2-3) Evaluation of polymerization activity of bisphenol C Using the bisphenol C obtained in (2-1), a polymerization reaction was carried out in the same manner as in Example 1. The time from when the temperature was raised to 280°C to when the polymerization was completed (second stage polymerization time) was 172 minutes.

[Example 3]
(3-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2), and step (A2) were performed to obtain a bisphenol C cake and crystallization filtrate. .

<Step (A3)>
508.0 g of the crystallized filtrate obtained in step (A2) was added to a 1 L distillation flask equipped with a thermometer, a distillation tube with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, and sodium hydrogen carbonate. Add 0.5 g of (NaHCO ₃ ), heat to 80° C. with stirring, and hold for 30 minutes. Thereafter, while reducing the pressure to 647 hPa with a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 12.0% (distillation amount 61.2g/prepared amount 508.0g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 80. It was evaporated to 0% (distilled amount: 406.6 g/charged amount: 508.0 g x 100) to obtain toluene recovery solvent 3.
The amount of sodium hydrogen carbonate added to the crystallization filtrate was 0.098% by mass (0.5g/508.0g×100).

<Step (A4)>
100 g of toluene recovery solvent 3 obtained in step (A3) is supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing is performed while loosening the cake, and solid-liquid separation is performed using a centrifuge. I did it. This operation was repeated two more times to obtain a fine cake of bisphenol C.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 116 g of white bisphenol C.

(3-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (3-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 16.2 area % of phenol had been produced.

(3-3) Evaluation of polymerization activity of bisphenol C Using the bisphenol C obtained in (3-1), a polymerization reaction was carried out in the same manner as in Example 1. The time from when the temperature was raised to 280°C to when the polymerization was completed (second stage polymerization time) was 164 minutes.

[Example 4]
(4-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2), and step (A2) were performed to obtain a cake of bisphenol C and a crystallized filtrate. .

<Step (A3)>
In a 1 L distillation flask equipped with a thermometer, a distillation tube with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, 503.4 g of the distillation raw material obtained in step (A2) and sodium bicarbonate (NaHCO) were placed. Add 0.2g of ₃ ), heat to 80°C while stirring, and hold for 30 minutes. Thereafter, the recovered solvent was distilled off by simple distillation while reducing the pressure to 647 hPa with a vacuum pump. The distillation rate up to 11.6% (distillation amount 58.4g/prepared amount 503.4g x 100) was discarded as the first distillation, and the distillation rate was increased to 71% while gradually increasing the temperature of the oil bath to 110°C. The solvent was evaporated to 8% (distilled amount: 361.2 g/charged amount: 503.4 g x 100) to obtain recovered solvent 4. The amount of sodium hydrogen carbonate added to the distillation raw material was 0.040% by mass (0.2g/503.4g×100).

<Step (A4)>
100 g of toluene recovery solvent 4 obtained in step (A3) was supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing was performed while loosening the bisphenol C cake, and a centrifuge was used. Solid-liquid separation was performed. This operation was repeated two more times to obtain a fine cake of bisphenol C.
Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 115 g of white bisphenol C.

(4-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (4-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 16.0 area % of phenol had been produced.

(4-3) Evaluation of polymerization activity of bisphenol A polymerization reaction was carried out in the same manner as in Example 1 using bisphenol C obtained in (4-1). The time from when the temperature was raised to 280°C to when the polymerization was completed (second stage polymerization time) was 159 minutes.

[Example 5]
(5-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2), and step (A2) were performed to obtain a bisphenol C cake and crystallization filtrate. .

<Step (A3)>
501.8 g of the crystallized filtrate obtained in step (A2), 25% by mass, was placed in a 1 L distillation flask equipped with a thermometer, a distillation tube equipped with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath. Add 8.4 g of sodium hydroxide (NaOH) aqueous solution, heat to 80° C. with stirring, and hold for 30 minutes. Thereafter, while reducing the pressure to 647 hPa with a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 11.6% (distilled amount 58.0 g/charged amount 501.8 g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 76. It was evaporated to 4% (distilled amount: 383.4 g/charged amount: 501.8 g x 100) to obtain toluene recovery solvent 5.
The amount of sodium hydroxide added to the crystallization filtrate was 0.418% by mass (8.4g x 0.25/501.8g x 100).

<Step (A4)>
100 g of toluene recovery solvent 5 obtained in step (A3) is supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing is performed while loosening the cake, and solid-liquid separation is performed using a centrifuge. I did it. This operation was repeated two more times to obtain a fine cake.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 115 g of white bisphenol C.

(5-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (5-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 13.2 area % of phenol had been produced.

(5-3) Evaluation of polymerization activity of bisphenol C A polymerization reaction was carried out in the same manner as in Example 1 using the bisphenol C obtained in (5-1). The time from the time the temperature was raised to 280°C to the end of the polymerization (second stage polymerization time) was 163 minutes.

[Example 6]
(6-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2), and step (A2) were performed to obtain a bisphenol C cake and crystallization filtrate. .

<Step (A3)>
501.0 g of the crystallized filtrate obtained in step (A2), 25% by mass, was placed in a 1 L distillation flask equipped with a thermometer, a distillation tube equipped with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath. Add 3.6 g of potassium hydroxide (KOH) aqueous solution, heat to 80° C. with stirring, and hold for 30 minutes. Thereafter, while reducing the pressure to 647 hPa with a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 12.2% (distillation amount 61.0g/prepared amount 501.0g x 100) was discarded as the first distillation, and the distillation rate was increased to 76.0% while gradually increasing the temperature of the oil bath to 110°C. It was evaporated to 9% (distilled amount: 385.4 g/charged amount: 501.0 g x 100) to obtain toluene recovery solvent 6.
The amount of potassium hydroxide added to the crystallization filtrate was 0.180% by mass (3.6g x 0.25/501.0g x 100).

<Step (A4)>
100 g of toluene recovery solvent 5 obtained in step (A3) was supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing was performed while loosening the bisphenol C cake, and a centrifuge was used. Solid-liquid separation was performed. This operation was repeated two more times to obtain a fine cake of bisphenol C.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 116 g of white bisphenol C.

(6-2) Initial activity evaluation of bisphenol C 4.7 g of bisphenol C obtained in (6-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm were placed in a PTFE test tube, and heated with an aluminum block heater. It was heated at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 20.1 area % of phenol was produced.

(6-3) Evaluation of polymerization activity of bisphenol C Using bisphenol C obtained in (6-1), a polymerization reaction was carried out in the same manner as in Example 1. The time from when the temperature was raised to 280°C to when the polymerization was completed (second stage polymerization time) was 158 minutes.

[Comparative example 1]
(Ratio 1-1) Production of bisphenol C In the same manner as in Example 1, step (A1), step (x1), step (x2) and step (A2) were performed to obtain a cake of bisphenol C and a crystallized filtrate. Ta.

<Solvent recovery step (corresponding to step (A3))>
Put 501.3 g of the crystallization filtrate obtained in step (A2) into a 1 L distillation flask equipped with a thermometer, a distillation tube equipped with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, and stir. While heating the mixture to 80° C. and reducing the pressure to 647 hPa using a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 4.4% (distillation amount 22.3g/prepared amount 501.3g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 77. It was evaporated to 6% (distilled amount: 388.9 g/charged amount: 501.3 g x 100) to obtain toluene recovery solvent 7.

<Bisphenol C purification process (corresponding to step (A4))>
100 g of toluene recovery solvent 7 obtained in the solvent recovery step was supplied to 150 g of the bisphenol C cake obtained in step (A2), suspension washing was performed while loosening the bisphenol C cake, and solidification was performed using a centrifuge. Liquid separation was performed. This operation was repeated two more times to obtain a fine cake of bisphenol C.

Using an evaporator equipped with an oil bath, light boiling components were distilled off under reduced pressure at an oil bath temperature of 100° C. to obtain 115 g of white bisphenol C.

(Ratio 1-2) Initial activity evaluation of bisphenol C Put 4.7 g of bisphenol C obtained in (Ratio 1-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm into a PTFE test tube, and put it into an aluminum block. It was heated with a heater at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 0.3 area % of phenol had been produced.

(Ratio 1-3) Evaluation of polymerization activity of bisphenol C Using the purified bisphenol C obtained in (Ratio 1-1), a polymerization reaction was carried out in the same manner as in Example 1, but the predetermined amount of polymerization catalyst (400 mass ppm) was used. (479 μL of cesium carbonate aqueous solution), the polymerization reaction did not proceed.

[Reference example]
(Reference 1-1)
120 g of white bisphenol C was obtained in the same manner as in Comparative Example 1, except that instead of the solvent recovery step in Comparative Example 1, a solvent recovery step was performed as follows.

<Solvent recovery process>
Put 687.4 g of the crystallization filtrate obtained in step (A2) into a 1 L distillation flask equipped with a thermometer, a distillation tube equipped with Sulzer laboratory packing, a Liebig condenser, a stirring blade, and an oil bath, and stir. While heating the mixture to 80° C. and reducing the pressure to 647 hPa using a vacuum pump, the toluene recovery solvent was distilled off by simple distillation. The distillation rate up to 4.2% (distillation amount 28.9g/prepared amount 687.4g x 100) was discarded as the first distillation, and the temperature of the oil bath was gradually raised to 110°C until the distillation rate was 45. It was evaporated to 1% (distilled amount: 310.0 g/charged amount: 687.4 g x 100) to obtain toluene recovery solvent 9.

(Reference 1-2) Initial activity evaluation of bisphenol C Put 4.7 g of bisphenol C obtained in (Reference 1-1), 4.5 g of diphenyl carbonate, and 20 μL of a cesium carbonate aqueous solution adjusted to 453 ppm into a PTFE test tube, and put it into an aluminum block. It was heated with a heater at 190°C for 1 hour.
A portion of the obtained melt was taken out and the phenol production rate due to reaction with diphenyl carbonate was confirmed by high performance liquid chromatography, and it was found that 10.6 area % of phenol had been produced.

(Reference 1-3) Evaluation of polymerization activity of bisphenol C The time from raising the temperature to 280°C to completing the polymerization (second stage polymerization time) was 202 minutes.

In Examples 1 to 6 and Comparative Example 1, the type of basic compound used, the mass ratio of the basic compound expressed as basic compound/crystallization filtrate, and the distillation raw material expressed as distillate/charge amount Table 1 shows the recovery rate of phenol, the production rate of phenol by the reaction of purified bisphenol C with diphenyl carbonate, and the polymerization activity of purified bisphenol C.

From the results in Table 1, by distilling and recovering the recovered solvent in the presence of basic compounds, it is possible to suppress the contamination of activity inhibitors into the recovered solvent, and as a result, even if the recovered solvent is used, the polymerization activity is excellent. It can be seen that quality product bisphenol C can be obtained.

Bisphenol produced by the bisphenol method of the present invention can be used as raw materials for resins such as polycarbonate resin, epoxy resin, and aromatic polyester resin, as well as curing agents, color developers, antifading agents, and other bactericidal agents and antibacterial and antifungal agents. It is useful as an additive.

Claims (7)

A method for producing bisphenol, comprising the following steps (A1) to (A4).
Step (A1): In the presence of an acid catalyst, an aromatic alcohol is reacted with a ketone or an aldehyde to produce bisphenol. Step (A2): The bisphenol obtained in the step (A1) reacts with an aromatic hydrocarbon. Solid-liquid separation of the slurry solution (S) dispersed in the solvent containing the bisphenol to obtain the solid content (C) containing the bisphenol and the solution (e) containing the aromatic hydrocarbon Step (A3): the aromatic hydrocarbon A solution (E) containing at least a portion of the solution (e) containing a hydrocarbon, and any one or more basic compounds selected from the group consisting of sodium hydrogen carbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide. Step (A4) of distilling the distillation raw material (D) mixed with the above to recover the aromatic hydrocarbon recovery solvent (R): using a cleaning solvent containing the recovery solvent (R), Step of washing solid content (C) to obtain bisphenol having a step (y) between the step (A2) and the step (A3),
In the step (A1), a reaction is carried out in a reaction liquid (L1) containing an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, and a ketone or aldehyde, and the bisphenol produced is precipitated, and the bisphenol is dispersed. A step of obtaining a slurry reaction product liquid (S1),
The step (A2) is a step in which the slurry reaction product liquid (S1) is subjected to solid-liquid separation to obtain the solid content (C1) containing the bisphenol and the solution (e1-1) containing the aromatic hydrocarbon. can be,
In the step (y), the solution (e1-1) containing the aromatic hydrocarbon or the mixed solution (e1-2) of the solution (e1-1) and a basic aqueous solution is mixed with the aqueous phase (yW) and the A step of separating the organic phase (yO) containing aromatic hydrocarbons and removing the aqueous phase (yW) to obtain the organic phase (yO),
The method for producing bisphenol according to claim 1, wherein the solution (E) used in the step (A3) is the organic phase (yO). having a step (x1) and a step (x2) between the step (A1) and the step (A2),
In the step (A1), a reaction is carried out in a reaction liquid (L1) containing an acid catalyst, an aromatic hydrocarbon, an aromatic alcohol, and a ketone or aldehyde, and the bisphenol produced is precipitated, and the bisphenol is dispersed. A step of obtaining a slurry reaction product liquid (S1),
The step (x1) is a step of removing the aqueous phase (xW) from the slurry reaction product liquid (S1) to obtain an organic phase (xO) containing an aromatic hydrocarbon in which bisphenol is dissolved,
The step (x2) is a step of cooling the organic phase (xO) and precipitating bisphenol to obtain a slurry solution (S2) in which bisphenol is dispersed,
The method for producing bisphenol according to claim 1, wherein the slurry solution (S) used in the step (A2) is the slurry solution (S2). The method for producing bisphenol according to any one of claims 1 to 3 , wherein the acid catalyst is sulfuric acid. The method for producing bisphenol according to any one of claims 1 to 4 , wherein the aromatic hydrocarbon is toluene. 6. The bisphenol according to any one of claims 1 to 5 , wherein the bisphenol is 2,2-bis(4-hydroxy-3-methylphenyl)propane or 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane. The method for producing bisphenol described above. A method for producing a polycarbonate resin using bisphenol produced by the method for producing bisphenol according to any one of claims 1 to 6 .