JP7172308B2 - Method for producing bisphenol and method for producing polycarbonate resin - Google Patents

Description

The present invention relates to a method for producing bisphenol, in which bisphenol is obtained from an aromatic alcohol and a ketone or aldehyde in the presence of sulfuric acid. Moreover, it is related with the manufacturing method of polycarbonate resin using the obtained bisphenol.
The bisphenol produced by the method for producing bisphenol of the present invention includes resin raw materials such as polycarbonate resin, epoxy resin, and aromatic polyester resin, curing agents, color developers, anti-fading agents, and other bactericidal agents and antibacterial and antifungal agents. It is useful as an additive such as

Bisphenol is useful as a raw material for polymeric materials such as polycarbonate resins, epoxy resins, and aromatic polyester resins. As representative bisphenols, for example, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane and the like are known.

Bisphenol is also used as a raw material for optical materials such as optical polycarbonate resin in some fields. In recent years, further improvement in the quality of bisphenol as a raw material is required in order to obtain a polycarbonate with a more excellent color tone. For example, in order to produce a polycarbonate resin or the like by melt polymerization, bisphenol as a raw material is required to have an excellent color tone even in a molten state.

Such bisphenols are generally produced by condensing an aromatic alcohol with a ketone or aldehyde in the presence of an acid catalyst.
For example, Patent Document 1 describes a method for overcoming the problems of using chlorine gas or sulfuric acid alone as an acidic catalyst and for producing bisphenol safely and efficiently by mixing a phenol derivative, acetone, and hydrochloric acid. A production method is disclosed in which 2,2-bis(4-hydroxyphenyl)propane or a derivative thereof is obtained by reacting while dropping sulfuric acid.
In addition, Patent Document 2 discloses that a first mixture containing an acidic catalyst is mixed with a second mixture containing a specific phenol compound and a specific ketone compound or an aldehyde and a compound in order to suppress the generation of by-products. A method for producing a bisphenol compound is disclosed in which an organic solvent is added to at least one of the mixtures, and the second mixture is added to the first mixture for condensation reaction.

JP 2014-40376 A JP 2008-214248 A

However, in the method described in Patent Document 1, since hydrochloric acid is used as an acid catalyst, the problem of corrosion of equipment etc. is alleviated compared to the case where hydrochloric acid is used alone, but there is still a problem of corrosion. , further improvement was required.
Further, when the present inventors produced 2,2-bis(4-hydroxy-3-methylphenyl)propane by the method described in Patent Document 1, the resulting 2,2-bis(4-hydroxy-3 -methylphenyl)propane has a high Hazen color number in the molten state, and a polycarbonate resin was produced by a melt polymerization reaction using the 2,2-bis(4-hydroxy-3-methylphenyl)propane. The reaction did not proceed as expected.

Also, in the method described in Patent Document 2, hydrochloric acid is used as an acidic catalyst, and there is a problem of corrosion of equipment and the like. Furthermore, the obtained bisphenol is also not sufficient as a raw material for producing polycarbonate resins and the like by melt polymerization, and there is room for improvement.

An object of the present invention is to provide a method for producing bisphenol in which the formation of by-products is suppressed by the use of a sulfuric acid catalyst and the color tone of the bisphenol in the molten state is good.
It is another object of the present invention to provide a method for producing a polycarbonate resin that allows the melt polymerization reaction to proceed using the bisphenol to produce a polycarbonate resin with a good color tone.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the following inventions meet the above objects, and have completed the present invention.
[1] A method for producing bisphenol, wherein bisphenol is obtained by reacting the aromatic alcohol, the ketone or the aldehyde in a reaction solution containing the aromatic alcohol, the ketone or the aldehyde, and sulfuric acid, wherein sulfuric acid, A method for producing bisphenol, comprising a reaction liquid preparation step of supplying a second mixed liquid containing a ketone or aldehyde and an aromatic alcohol to a first mixed liquid containing an aromatic alcohol to prepare a reaction liquid.
[2] The mass ratio of the aromatic alcohol contained in the first liquid mixture to the sum of the aromatic alcohols contained in the first liquid mixture and the aromatic alcohol contained in the second liquid mixture is 0.5. The method for producing bisphenol according to [1], which is 20 or more and 0.90 or less.
[3] The method for producing bisphenol according to [1] or [2], wherein the first mixed solution further contains an organic solvent.
[4] The method for producing bisphenol according to [3], wherein the organic solvent contains an aromatic hydrocarbon and an aliphatic alcohol.
[5] wherein the aromatic alcohol is ortho-cresol, the ketone or aldehyde is acetone, and the bisphenol is 2,2-bis(4-hydroxy-3-methylphenyl)propane [1] to [4] The method for producing bisphenol according to any one of .
[6] A method for producing a polycarbonate resin, comprising producing a polycarbonate using bisphenol produced by the method for producing bisphenol according to any one of [1] to [5].

According to the present invention, the production of by-products is suppressed, and bisphenol having a good color tone in the molten state can be produced. Moreover, using the obtained bisphenol, the melt polymerization reaction proceeds easily, and a polycarbonate resin with a good color tone can be produced.

The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention does not exceed the gist thereof. is not limited to
In addition, when the expression "~" is used in this specification, it is used as an expression including numerical values or physical property values before and after it.

In a method for producing bisphenol, the aromatic alcohol and the ketone or aldehyde are reacted in a reaction solution containing an aromatic alcohol, a ketone or an aldehyde, and sulfuric acid to obtain a bisphenol, wherein sulfuric acid and the aromatic alcohol A method for producing bisphenol having a reaction liquid preparation step of supplying a second mixed liquid containing a ketone or aldehyde and an aromatic alcohol to a first mixed liquid containing and preparing a reaction liquid (hereinafter referred to as "this (referred to as "the method for producing bisphenol of the invention").

The present inventors have found that when sulfuric acid is used as a catalyst, the quality of the bisphenol obtained is affected by the mixing order of the raw materials when preparing the reaction solution. In particular, when the production scale is large, it takes a long time to prepare the reaction solution and complete the bisphenol production reaction, so the quality of the bisphenol obtained is greatly affected by the mixing order of the raw materials when preparing the reaction solution. I got some insight.
As a result of investigating the cause of this, it was found that the color tone of the bisphenol in a molten state deteriorates due to the generation of coloring components due to contact between sulfuric acid and aromatic alcohol. In addition, the inventors have found that the aromatic alcohol sulfonic acid, which is a by-product of the contact between sulfuric acid and aromatic alcohol, remains in the bisphenol product and becomes an activity-reducing component in the melt polymerization reaction.
Furthermore, they have found that if the amount of the aromatic alcohol relative to the ketone or aldehyde is small at the initial stage of the reaction, self-condensation of the ketones or aldehydes occurs, resulting in an increase in by-products derived from dimers of the ketones or aldehydes.
Among them, by-products derived from aromatic alcohol sulfonic acids and dimers of ketones or aldehydes represent a loss of raw materials for bisphenol, so it is important to control the amount of these produced. In particular, the inventors have found that it is important to suppress the production of by-products derived from dimers of ketones or aldehydes, since they are considered to have a correlation with the color tone of bisphenol. The present invention is based on these findings.

One of the characteristics of the method for producing bisphenol of the present invention is that a second mixed liquid containing a ketone or aldehyde and an aromatic alcohol is supplied to a first mixed liquid containing sulfuric acid and an aromatic alcohol to react. It is to prepare the liquid.
More specifically, in the method for producing bisphenol of the present invention, the aromatic alcohol (hereinafter referred to as "aromatic alcohol (T)") used for the reaction with the ketone or aldehyde is added to the aromatic alcohol contained in the first mixed liquid. The reaction liquid is divided into an aromatic alcohol (hereinafter referred to as "aromatic alcohol (A)") and an aromatic alcohol contained in the second mixed liquid (hereinafter referred to as "aromatic alcohol (B)"). to prepare. The amount of aromatic alcohol (A) is the amount of aromatic alcohol (T) minus the amount of aromatic alcohol (B). The aromatic alcohol (T) contained in the prepared reaction solution, the aromatic alcohol (A) contained in the first mixed solution, and the aromatic alcohol (B) contained in the second mixed solution are of the same type. is an aromatic alcohol.

In this way, the aromatic alcohol used in the method for producing bisphenol of the present invention is divided into the first mixed liquid and the second mixed liquid, and the amount of the aromatic alcohol in the first mixed liquid is reduced. Since the amount of aromatic alcohol that comes into contact with sulfuric acid is reduced during the preparation of mixed solution 1, it is possible to suppress the by-production of aromatic alcohol sulfonic acid due to the reaction between sulfuric acid and aromatic alcohol.

In addition, since the presence of sulfuric acid, an aromatic alcohol, and a ketone or aldehyde in the same system causes a bisphenol production reaction, preparation of a reaction solution containing an aromatic alcohol, a ketone or aldehyde, and sulfuric acid Bisphenol formation reactions occur even in stages. In the method for producing bisphenol of the present invention, the aromatic alcohol and the ketone or aldehyde are not separately supplied, but are supplied as a second mixed liquid containing the aromatic alcohol and the ketone or aldehyde, whereby the bisphenol production reaction is initiated by feeding the second mixed liquid to the first mixed liquid. It is possible to suppress the contact between sulfuric acid and the aromatic alcohol at the initial stage of the reaction (the stage at which the supply of the second mixed solution is started), and suppress the generation of the by-product aromatic alcohol sulfonic acid. be able to.

Furthermore, by having the first liquid mixture contain the aromatic alcohol, when the supply of the second liquid mixture initiates the reaction between the aromatic alcohol and the ketone or aldehyde, the aromatic alcohol relative to the ketone or aldehyde can be increased. Therefore, it is possible to suppress the production of by-products derived from dimers of ketones or aldehydes.

Further, in order to supply the second mixed liquid containing the ketone or aldehyde and the aromatic alcohol to the first mixed liquid containing the sulfuric acid and the aromatic alcohol, the first mixed liquid is added to the second mixed liquid. The reaction can be carried out in a state where the concentration of ketone or aldehyde is low compared to the case of supplying .

In order to further suppress the production of aromatic alcohol sulfonic acid due to the reaction between sulfuric acid and aromatic alcohol in the first mixed liquid, the first mixed liquid preferably further contains an organic solvent.

In the method for producing bisphenol of the present invention, the second mixed liquid is supplied to the first mixed liquid to prepare a reaction liquid containing an aromatic alcohol, a ketone or aldehyde, and sulfuric acid, and then , reacting aromatic alcohols with ketones or aldehydes to produce bisphenols. In the production reaction of bisphenol, a ketone or aldehyde and an aromatic alcohol are usually condensed according to the reaction formula (1) shown below to produce a bisphenol represented by the following general formula (2).

In reaction formula (1) and general formula (2), R ¹ to R ⁴ each independently include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, and the like. Alkyl groups, alkoxy groups, aryl groups and the like may be substituted or unsubstituted. For example, 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, cycloheptyl group, cyclooctyl group , cyclododecyl group, benzyl group, phenyl group, tolyl group, 2,6-dimethylphenyl group and the like.

Of these, R ² and R ³ are preferably hydrogen atoms because the condensation reaction is difficult to proceed if they are sterically bulky. More preferably, R ¹ to R ⁴ are each independently hydrogen atoms or alkyl groups, R ¹ and R ⁴ are each independently hydrogen atoms or alkyl groups, and R ² and R ³ are hydrogen atoms. is more preferable.

R ⁵ and R ⁶ each independently include a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and the like. Alkyl groups, alkoxy groups, aryl groups and the like may be substituted or unsubstituted. For example, proton, 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-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, cycloheptyl 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 linked or bridged with each other between the two groups, and R ⁵ and R ⁶ may be linked together with adjacent carbon atoms to form a cycloalkylidene group. The cycloalkylidene group is a divalent group obtained by removing two hydrogen atoms from one carbon atom of cycloalkane.
The cycloalkylidene group formed by combining R ⁵ and R ⁶ together with adjacent carbon atoms includes, for example, cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, 3,3,5-trimethyl Cyclohexylidene, cycloheptylidene, cyclooctylidene, cyclononylidene, cyclodecylidene, cycloundecylidene, cyclododecylidene, fluorenylidene, xanthonylidene, thioxantonylidene and the like.

Specific examples of the compound represented by the general formula (2) include 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)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-3-methylphenyl) Examples include, but are not limited to, heptane, 4,4-bis(4-hydroxyphenyl)heptane, 4,4-bis(4-hydroxy-3-methylphenyl)heptane, and the like.

Among these, the method for producing bisphenol of the present invention is a method for producing 2,2-bis(4-hydroxy-3-methylphenyl)propane or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane. It is preferable to
In addition, since the effect of suppressing by-products and improving color tone is high, the method for producing 2,2-bis(4-hydroxy-3-methylphenyl)propane is more preferable. More specifically, the aromatic alcohol is ortho-cresol, the ketone or aldehyde is acetone, and the bisphenol is 2,2-bis(4-hydroxy-3-methylphenyl)propane. preferable.

[Aromatic alcohol]
The aromatic alcohol (aromatic alcohol (T)) used in the method for producing bisphenol of the present invention is divided into the aromatic alcohol (A) and the aromatic alcohol (B) when preparing the reaction solution. , is usually a compound represented by the following general formula (3).

（式中、Ｒ¹～Ｒ⁴は、一般式（２）におけるものと同義である。）

(In the formula, R ¹ to R ⁴ have the same definitions as in general formula (2).)

Of these, R ² and R ³ are preferably hydrogen atoms because the condensation reaction is difficult to proceed if they are sterically bulky.

More preferably, R ¹ to R ⁴ are each independently hydrogen atoms or alkyl groups, R ¹ and R ⁴ are each independently hydrogen atoms or alkyl groups, and R ² and R ³ are hydrogen atoms is more preferred.

Specific examples of the compound represented by the general formula (3) include phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol, methoxyphenol, ethoxyphenol, propoxyphenol, butoxyphenol, aminophenol, benzylphenyl, phenylphenol and the like.

Among them, one selected from the group consisting of phenol, cresol, and xylenol is preferable, cresol or xylenol is more preferable, and cresol is even more preferable. Cresols include ortho-cresol or meta-cresol, with ortho-cresol being preferred.

[Ketones and aldehydes]
The ketone and aldehyde used in the production method of the present invention are usually compounds represented by the following general formula (4).

（式中、Ｒ⁵及びＲ⁶は、一般式（２）におけるものと同義である。）

(Wherein, R ⁵ and R ⁶ have the same definitions as in general formula (2).)

Specific examples of the compound represented by the general formula (4) include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentanaldehyde, hexanaldehyde, heptanaldehyde, octanaldehyde, nonanaldehyde, decanealdehyde, undecanealdehyde, and dodecane. Aldehydes such as aldehydes, ketones such as acetone, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone, undecanone, dodecanone, benzaldehyde, phenylmethylketone, phenylethylketone, phenylpropylketone, cresylmethylketone, cresylmethylketone Arylalkyl ketones such as dilethylketone, cresylpropylketone, xylylmethylketone, xylylethylketone, xylylpropylketone, cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclononanone , cyclodecanone, cycloundecanone, cyclododecanone, and other cyclic alkane ketones. Among them, acetone is preferred.

<Reaction solution preparation step>
The method for producing bisphenol of the present invention has a reaction solution preparation step. The reaction liquid preparation step is a step of supplying a second liquid mixture containing a ketone or aldehyde and an aromatic alcohol to a first liquid mixture containing sulfuric acid and an aromatic alcohol to prepare a reaction liquid. .

As described above, the aromatic alcohol (T) used in the method for producing bisphenol of the present invention is the aromatic alcohol (A) contained in the first mixed liquid and the aromatic alcohol (B ) and used by dividing into two.
The total amount of aromatic alcohol (A) and aromatic alcohol (B) (i.e., aromatic alcohol (T)) depends on the amount of ketone or aldehyde contained in the second mixture and the presence or absence of an organic solvent. It is determined. The molar ratio of the aromatic alcohol (T) to the ketone or aldehyde contained in the second mixture ((number of moles of aromatic alcohol (T) / number of moles of ketone contained in the second mixture) or (aromatic When the number of moles of alcohol (T)/the number of moles of aldehyde contained in the second liquid mixture)) is small, ketones or aldehydes tend to increase. For this reason, the molar ratio of the aromatic alcohol (T) to the ketone or aldehyde contained in the second mixture is preferably 1.5 or more, more preferably 1.6 or more, and still more preferably 1.7 or more. be.

Also, when aromatic alcohol is used as a substitute for the organic solvent, a large amount of aromatic alcohol can be used relative to the ketone or aldehyde, but in this case, much of the aromatic alcohol remains unreacted. Unreacted aromatic alcohol can be recovered and purified by distillation or the like and reused, but if there is too much unreacted aromatic alcohol, operations such as distillation become more complicated. Accordingly, the molar ratio of the aromatic alcohol (T) to the ketone or aldehyde contained in the second mixture is preferably 15 or less, more preferably 10 or less, and even more preferably 8 or less.

Furthermore, the ratio of dividing the aromatic alcohol (T) into the aromatic alcohol (A) and the aromatic alcohol (B) is appropriately determined according to the amounts of sulfuric acid and the organic solvent.
In order to further suppress the formation of by-products derived from self-condensation products of ketones or aldehydes and to obtain bisphenol with better color tone in the molten state, aromatic alcohol (A) and aromatic alcohol (B) The mass ratio of the aromatic alcohol (A) to the total (aromatic alcohol (T)) (mass of aromatic alcohol (A)/mass of aromatic alcohol (T)) is preferably 0.20 or more, and 0.25 The above is more preferable. Further, in order to further suppress the by-production of aromatic alcohol sulfonic acid and the like and to obtain a bisphenol having a better color tone in the molten state, the aromatic alcohol with respect to the total of the aromatic alcohol (A) and the aromatic alcohol (B) The mass ratio of (A) is preferably 0.90 or less, more preferably 0.80 or less.

[First mixed solution]
The first mixed liquid contains sulfuric acid and aromatic alcohol (A). When the molar ratio of sulfuric acid to the aromatic alcohol (A) (the number of moles of sulfuric acid/the number of moles of the aromatic alcohol (A)) is small, the reaction time becomes long. Further, when the amount is large, a side reaction between sulfuric acid and aromatic alcohol sulfonic acid tends to occur during preparation of the reaction solution, and aromatic alcohol sulfonic acid and the like are likely to be produced. For these reasons, the molar ratio of sulfuric acid to aromatic alcohol (A) is preferably 0.5 or more, more preferably 0.7 or more, and still more preferably 1.0 or more. Moreover, the upper limit is preferably 50 or less, more preferably 25 or less. Moreover, the upper limit may be 10 or less or 5 or less.

(sulfuric acid)
Sulfuric acid is an acidic liquid represented by the chemical _{formula H2SO4} . Sulfuric acid is generally used as an aqueous sulfuric acid solution diluted with water, and is called concentrated sulfuric acid or dilute sulfuric acid depending on its concentration. For example, dilute sulfuric acid is an aqueous sulfuric acid solution having a mass concentration of less than 90% by mass.
If the concentration of sulfuric acid used (concentration of H ₂ SO ₄ in the aqueous sulfuric acid solution) is high, the self-condensation reaction of ketones or aldehydes tends to proceed, which may lead to deterioration of the color tone of bisphenol and reduction in reaction selectivity of bisphenol. In addition, if the concentration of sulfuric acid used is low, the amount of water increases, making it difficult for the reaction to produce bisphenol to proceed, and the reaction time to produce bisphenol becomes longer, making it difficult to produce bisphenol efficiently. be. Therefore, the concentration of sulfuric acid used is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. Also, the concentration of sulfuric acid used can be 99.5% by mass or less or 99% by mass or less.
The concentration of sulfuric acid is the concentration of the sulfuric acid aqueous solution used when preparing the reaction solution, and is the concentration at the time of preparation.

The first mixed solution may consist of sulfuric acid and aromatic alcohol (A), or may contain components other than sulfuric acid and aromatic alcohol (A). Examples of components other than sulfuric acid and aromatic alcohol (A) include organic solvents and co-catalysts such as thiols. In order to further suppress the generation of aromatic alcohol sulfonic acid due to the reaction of sulfuric acid with the aromatic alcohol in the first mixed liquid, the first mixed liquid preferably further contains an organic solvent.

(organic solvent)
The organic solvent is not particularly limited as long as it does not inhibit the production reaction of bisphenol, and examples thereof include aromatic hydrocarbons, aliphatic alcohols, and aliphatic hydrocarbons. may be used in combination. When the organic solvent is recovered, purified and reused after completion of the reaction, a solvent with a low boiling point is preferred.

Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, and mesitylene. These solvents may be used alone or in combination of two or more. After being used for the production of bisphenol, aromatic hydrocarbons can be recovered and purified by distillation or the like and reused. When reusing aromatic hydrocarbons, those having a low boiling point are preferred.

Aliphatic alcohols are alkyl alcohols in which an alkyl group and a hydroxyl group are attached. In the present invention, the aliphatic alcohol may be a monohydric alcohol in which an alkyl group and one hydroxyl group are bonded, or a polyhydric alcohol in which an alkyl group and two or more hydroxyl groups are bonded. In addition, the alkyl group may be linear or branched, unsubstituted, or part of the carbon atoms of the alkyl group may be substituted with oxygen atoms.

As the number of carbon atoms increases, the aliphatic alcohol increases in lipophilicity and becomes difficult to mix with sulfuric acid. Therefore, the number of carbon atoms is preferably 12 or less, more preferably 8 or less.

Further, the aliphatic alcohol is preferably a monohydric alcohol in which an alkyl group and one hydroxyl group are bonded, and is a monohydric alcohol in which an alkyl group having 1 to 12 carbon atoms and one hydroxyl group are bonded. is more preferable, and an alcohol in which an alkyl group having 1 to 8 carbon atoms and one hydroxyl group are bonded is even more preferable.

Specific aliphatic alcohols include, for example, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, n-pentanol, i-pentanol, n-hexanol, n -heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, ethylene glycol, diethylene glycol, triethylene glycol and the like.

In particular, by using an organic solvent containing an aliphatic alcohol as the organic solvent in the first mixed liquid, the acid strength of sulfuric acid can be controlled, the condensation (multimerization) of ketones or aldehydes can be further suppressed, and coloration can be further suppressed, it is preferable to use an organic solvent containing an aliphatic alcohol.

When using an organic solvent containing an aliphatic alcohol as the organic solvent, it is preferable to control the amount of the aliphatic alcohol according to the amount of sulfuric acid. By controlling the amount of the aliphatic alcohol, the acidity of sulfuric acid can be controlled, and the generation of side reactions, coloration, and the like can be further suppressed. When the molar ratio of aliphatic alcohol to sulfuric acid (H ₂ SO ₄ ) (moles of aliphatic alcohol/moles of sulfuric acid) is small, the amount of unreacted sulfuric acid increases, leading to condensation (polymerization) of the starting ketone or aldehyde. And coloring may become remarkable. Also, even if the molar ratio of the aliphatic alcohol to the sulfuric acid (H ₂ SO ₄ ) is high, the concentration of sulfuric acid decreases and the reaction slows down, requiring a long time for the reaction. For these reasons, the lower limit of the molar ratio of aliphatic alcohol to sulfuric acid is preferably 0.01 or more, more preferably 0.05 or more, and still more preferably 0.1 or more. Moreover, the upper limit is preferably 10 or less, more preferably 5 or less, and still more preferably 3 or less.

The generated bisphenol is less likely to decompose if it is dispersed in the organic solvent without being completely dissolved. In addition, it is preferable to use a solvent having a low solubility of bisphenol, since loss during recovery of bisphenol from the reaction solution after completion of the reaction (for example, loss to the filtrate during crystallization) can be reduced. Solvents in which bisphenol has low solubility include, for example, aromatic hydrocarbons. For this reason, the organic solvent preferably contains an aromatic hydrocarbon as a main component, and preferably contains 55% by mass or more of the aromatic hydrocarbon in the organic solvent, more preferably 70% by mass or more, and 80% by mass. % or more is more preferable. One of the preferred aromatic hydrocarbons is toluene because bisphenol is difficult to dissolve and has a low boiling point.

Organic solvents that are more preferable as the organic solvent in the first liquid mixture include aromatic hydrocarbons and aliphatic alcohols because they can control the acidity of sulfuric acid and facilitate dispersion of bisphenol. For example, the organic solvent in the first liquid mixture may contain 90 to 99.9% by mass of aromatic hydrocarbons and 0.1 to 10% by mass of aliphatic alcohols.

A method for preparing the first mixed solution is not particularly limited, and sulfuric acid may be supplied to the aromatic alcohol (A), or sulfuric acid may be supplied to the aromatic alcohol (A). In order to suppress sulfonation of the aromatic alcohol (A), it is preferable to supply sulfuric acid to the aromatic alcohol (A). Moreover, when the first mixed solution contains components other than sulfuric acid and the aromatic alcohol (A), the components can be mixed in advance with the sulfuric acid or the aromatic alcohol (A).

[Second mixed solution]
The second liquid mixture contains aromatic alcohol (B) and ketone or aldehyde. The amount of the aromatic alcohol (B) used is the amount obtained by subtracting the amount used as the aromatic alcohol (A) from the amount of the aromatic alcohol (T) used in the reaction. Ketones or aldehydes are as described above.

The second liquid mixture may consist of the aromatic alcohol (B) and the ketone or aldehyde, or may contain components other than the aromatic alcohol (B) and the ketone or aldehyde. Examples of components other than the aromatic alcohol (B) and the ketone or aldehyde include organic solvents and co-catalysts such as thiols.

The second liquid mixture preferably contains a thiol as a co-catalyst. Thiols to be used include, for example, mercaptocarboxylic acids such as mercaptoacetic acid, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and 4-mercaptobutyric acid, methylmercaptan, ethylmercaptan, propylmercaptan, butylmercaptan, and pentylmercaptan. , hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, undecyl and dodecyl mercaptan.

In the second mixture, if the molar ratio of thiol to ketone or aldehyde ((moles of thiol/moles of ketone) or (moles of thiol/moles of aldehyde)) is low, the reaction selection of bisphenol It is difficult to obtain the effect of improving the sexuality. The reaction selectivity of bisphenol is an index of the ease with which the target bisphenol is produced in the bisphenol production reaction. Moreover, when it is large, it mixes with bisphenol and deteriorates the quality. For these reasons, the molar ratio of thiol to ketone or aldehyde is preferably 0.001 or more, more preferably 0.005 or more, still more preferably 0.01 or more, and preferably 1 or less, more preferably 0 0.5 or less, more preferably 0.1 or less.

Like the first mixed liquid, the second mixed liquid preferably contains an organic solvent. The organic solvent contained in the second mixed liquid is not particularly limited as long as it does not inhibit the reaction for producing bisphenol, similarly to the organic solvent contained in the first mixed liquid. Group hydrocarbons and the like can be used. These solvents may be used alone or in combination of two or more. Moreover, it may be the same as or different from the organic solvent contained in the first mixed liquid. Aromatic hydrocarbons are preferable as the organic solvent contained in the second liquid mixture.

The method for preparing the second liquid mixture is not particularly limited, and the aromatic alcohol (B) may be supplied with the ketone or aldehyde, or the ketone or aldehyde may be supplied with the aromatic alcohol (B). Moreover, when the second liquid mixture contains a component other than the aromatic alcohol (B) and the ketone or aldehyde, the component can be premixed with the aromatic alcohol (B), ketone or aldehyde.

If the second mixture contains a thiol as a cocatalyst, it is preferably premixed with the ketone or aldehyde before mixing with the aromatic alcohol. A method of mixing a thiol with a ketone or aldehyde may supply the thiol with the ketone or aldehyde, or may supply the ketone or aldehyde with the thiol.

[supply]
The supply time for supplying the second mixed liquid to the first mixed liquid is appropriately determined according to the amount, concentration, etc. of the aromatic alcohol, ketone, or aldehyde. Since the bisphenol production reaction occurs even when the second mixed liquid is supplied to the first mixed liquid, if the supply time for supplying the second mixed liquid to the first mixed liquid is too short, the reaction temperature can not be controlled, by-products tend to increase. Moreover, if the supply time for supplying the second mixed liquid to the first mixed liquid is too long, the reaction time also becomes long, and the production efficiency tends to decrease. Therefore, the lower limit of the supply time is preferably 0.3 hours or longer, more preferably 0.5 hours or longer. Moreover, the upper limit is preferably 5 hours or less. Alternatively, the time may be set to 3 hours or less or 1 hour or less.

Further, if the temperature (supply temperature) at which the second mixed liquid is supplied to the first mixed liquid is too low, the reaction liquid tends to solidify, and the bisphenol production reaction may be difficult to proceed. Also, if the temperature is too high, the generated bisphenol tends to decompose. For these reasons, the lower limit of the supply temperature is preferably −20° C. or higher, more preferably −10° C. or higher. Moreover, the upper limit thereof is preferably 40° C. or lower, more preferably 30° C. or lower.

An example of the method for preparing the reaction solution in the method for producing bisphenol of the present invention is described below.
1st step: A reactor is fed with an aromatic hydrocarbon and an aliphatic alcohol.
2nd step: The aromatic alcohol (A) is supplied to the reactor supplied with the aromatic hydrocarbon and the aliphatic alcohol.
Third step: Sulfuric acid is supplied to the reactor supplied with the aromatic hydrocarbon, the aliphatic alcohol and the aromatic alcohol (A) to prepare a first mixed solution.
Fourth step: A ketone or aldehyde, an aromatic hydrocarbon, a promoter thiol, and an aromatic alcohol (B) are fed into another vessel to prepare a second mixed liquid.
Fifth step: supplying the second mixed liquid to the reactor containing the first mixed liquid.

<Reaction step>
In the method for producing bisphenol of the present invention, after the reaction liquid is prepared in the reaction liquid preparation step, the reaction liquid is further stirred to proceed with the bisphenol production reaction.

When the reaction temperature is high, ketones or aldehydes are multimerized, and when it is low, the reaction takes a long time. Accordingly, the reaction temperature can be -30°C or higher, -20°C or higher, or -15°C or higher. It is preferably 0° C. or higher, more preferably 5° C. or higher, and still more preferably 10° C. or higher. Moreover, the upper limit thereof is preferably 100° C. or lower, more preferably 80° C. or lower, and still more preferably 70° C. or lower.

In the present invention, the reaction time is preferably 30 hours or less, more preferably 25 hours or less, still more preferably 20 hours or less, because the bisphenol produced is decomposed if the reaction time is long. Moreover, the lower limit can be 0.3 hours or more or 0.5 hours or more.
The reaction can be terminated by adding water in an amount equal to or greater than the amount of sulfuric acid used to lower the concentration of sulfuric acid.

<Purification process>
In the method for producing bisphenol of the present invention, the bisphenol obtained by the condensation reaction can be purified by a conventional method. For example, it can be purified by simple means such as crystallization and column chromatography. Specifically, after the condensation reaction, the organic phase obtained by liquid separation of the reaction solution is washed with water or saline, and if necessary, neutralized and washed with sodium bicarbonate water or the like. The washed organic phase is then cooled and crystallized. When a large amount of aromatic alcohol is used, crystallization can be carried out after distilling off excess aromatic alcohol by distillation before the crystallization. In addition, crystallization can be performed multiple times.

<Uses of bisphenol>
Bisphenol produced by the method for producing bisphenol of the present invention (hereinafter sometimes referred to as "the bisphenol of the present invention") can be used as optical materials, recording materials, insulating materials, transparent materials, electronic materials, adhesive materials, and heat-resistant materials. Various thermoplastic resins such as polyether resins, polyester resins, polyarylate resins, polycarbonate resins, polyurethane resins, acrylic resins, epoxy resins, unsaturated polyester resins, phenolic resins, and polybenzoxazine resins. , cyanate resin, etc., as a constituent component of various thermosetting resins, a curing agent, an additive, or a precursor thereof. It is also useful as an additive such as a color developer for heat-sensitive recording materials, an anti-fading agent, a bactericide, and an antibacterial and antifungal agent.

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

[Method for producing polycarbonate resin]
The method for producing a polycarbonate resin using the bisphenol of the present invention as a raw material comprises transesterifying the bisphenol of the present invention and a carbonic acid diester such as diphenyl carbonate in the presence of, for example, an alkali metal compound and/or an alkaline earth metal compound. It can be a manufacturing method of manufacturing by a method of causing. The transesterification reaction can be carried out by appropriately selecting a known method, and 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 an excess amount of diphenyl carbonate relative to the bisphenol of the present invention. The amount of diphenyl carbonate used relative to the bisphenol is preferably large in terms of the produced polycarbonate resin having few terminal hydroxyl groups and excellent thermal stability of the polymer. From the viewpoint of easy production of the polycarbonate resin, it is preferable that the amount is small. For these reasons, the amount of diphenyl carbonate used per 1 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. is.

As a 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.

A catalyst is usually used when producing a polycarbonate resin by the transesterification reaction between diphenyl carbonate and bisphenol. In the method for producing a polycarbonate resin described above, 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 two or more of them may be used in any combination and ratio. Practically, it is desirable to use an alkali metal compound.

The amount of catalyst used per 1 mol 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.

When the amount of the catalyst used is within the above range, it is easy to obtain the polymerization activity necessary for producing a polycarbonate resin having a desired molecular weight, and the polymer hue is excellent, and excessive branching of the polymer does not proceed, It is easy to obtain a 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 the above raw materials to a raw material mixing tank, and continuously supply the resulting mixture and a transesterification catalyst to a polymerization tank.
In the production of a polycarbonate resin by the transesterification method, both raw materials supplied to a raw material mixing tank are generally stirred uniformly and then fed to a polymerization tank in which a catalyst is added to produce a polymer.

The bisphenol of the present invention has a low content of components that inhibit the melt polymerization reaction and has a good color tone even in a molten state, so that a polycarbonate resin with a good color tone can be produced.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited by the following examples as long as the gist thereof is not exceeded.

[Raw materials and reagents]
Orthocresol, toluene, sodium hydroxide, sulfuric acid, dodecanethiol, methanol, acetone, sodium hydrogencarbonate, and cesium carbonate were reagents manufactured by Wako Pure Chemical Industries, Ltd.
A product manufactured by Mitsubishi Chemical Corporation was used as diphenyl carbonate.

[analysis]
(Quantitative analysis of bisphenol C, etc.)
Quantitative analysis of ortho-cresol, bisphenol C, {2-(4-hydroxy-3-methylphenyl)-2-methylpropyl}methylketone (hereinafter referred to as MOPC) was performed by high performance liquid chromatography under the following procedures and conditions. gone.
・ Apparatus: LC-2010A manufactured by Shimadzu Corporation, Imtakt Scherzo SM-C18 3 μm 150 mm × 4.6 mm ID
・Low pressure gradient method ・Analysis temperature: 40°C
・ Eluent composition A solution A ammonium acetate: acetic acid: demineralized water = 3.000 g: 1 mL: 1 L solution B solution Ammonium acetate: acetic acid: acetonitrile = 1.500 g: 1 mL: 900 mL solution ・ At analysis time 0 minutes, A solution: Liquid B = 60:40 (volume ratio, the same shall apply hereinafter.)
Analysis time 0 to 25 minutes gradually change the eluent composition to A solution: B solution = 90: 10,
Analysis time 25 to 30 minutes is maintained at A solution: B solution = 90: 10,
Analysis was performed at a flow rate of 0.8 mL/min and a detection wavelength of 280 nm.

The quantification of ortho-cresol and MOPC was carried out by the absolute calibration method by creating a calibration curve using ortho-cresol. Bisphenol C was quantified by an absolute calibration method by preparing a calibration curve using bisphenol C.

(Melting color difference of bisphenol C (Hazen color number))
The melting color difference of bisphenol C was measured by placing 20 g of bisphenol C in a test tube of Nichiden Rika Glass P-24 24 mmφ x 200 mm, melting at 190 ° C. for 30 minutes, and measuring the Hazen color number using SE6000 manufactured by Nippon Denshoku Industries Co., Ltd. .

(Viscosity average molecular weight (Mv) of polycarbonate resin)
The viscosity-average molecular weight (Mv) of the polycarbonate resin is obtained by dissolving the polycarbonate resin in methylene chloride (concentration: 6.0 g/L), measuring the specific viscosity (ηsp) at 20°C using an Ubbelohde viscosity tube, and calculating the following formula: A viscosity average molecular weight (Mv) was calculated.
ηsp/C=[η](1+0.28ηsp)
[η]=1.23×10 ⁻⁴ Mv ^0.83

(Terminal hydroxyl group concentration of polycarbonate resin)
The terminal hydroxyl group concentration (OH concentration) of the polycarbonate resin was measured by colorimetric determination according to the titanium tetrachloride/acetic acid method (see Makromol. Chem. 88, 215 (1965)).

(Polycarbonate resin pellet YI)
The polycarbonate resin pellet YI (transparency of polycarbonate resin) was evaluated by measuring the YI value (yellowness index value) of the polycarbonate resin pellet in reflected light according to ASTM D1925.
Apparatus; Spectrophotometer CM-5 manufactured by Konica Minolta
Measurement conditions; measurement diameter 30 mm, SCE was selected.
Calibration: A calibration glass CM-A212 for petri dish measurement was fitted into the measurement part, and a zero calibration box CM-A124 was placed over it to perform zero calibration, followed by white calibration using the built-in white calibration plate. Next, measurement was performed using a white calibration plate CM-A210, L * was 99.40 ± 0.05, a * was 0.03 ± 0.01, b * was -0.43 ± 0.01, YI was -0.58±0.01.
Measurement: Pellets were measured by filling a cylindrical glass container with an inner diameter of 30 mm and a height of 50 mm to a depth of about 40 mm. The operation of taking out the pellets from the glass container and measuring again was repeated twice, and the average value of the measured values of a total of three times was used.

[Example 1]
230 g of ortho-cresol was divided into 60 g and 170 g, and reaction liquids were prepared using 60 g of ortho-cresol in the first mixed liquid (bed liquid) and 170 g of ortho-cresol in the second mixed liquid. The ratio of ortho-cresol in the first mixed liquid to the total ortho-cresol (bedding ratio: the above-mentioned relative to the sum of the aromatic alcohol contained in the first mixed liquid and the aromatic alcohol contained in the second mixed liquid The mass ratio of the aromatic alcohol contained in the mixed liquid of No. 1×100) was 60 g÷230 g×100=26%.

(1) Preparation of first mixed solution In a separable flask equipped with a thermometer, a dropping funnel, a jacket and an anchor-type stirring blade, 320 g of toluene, 12 g of methanol, and 60 g (0.56 mol) of ortho-cresol were added under a nitrogen atmosphere. The internal temperature was adjusted to 10°C or less. After that, 95 g of 98% by weight sulfuric acid was added with stirring over 0.3 hours, and the mixture was allowed to stand at room temperature for 22 hours to prepare a first mixed solution (bedding solution).

(2) Preparation of second mixed solution In a 500 mL Erlenmeyer flask, 50 g of toluene, 170 g (1.6 mol) of orthocresol, 61 g (1.1 mol) of acetone, and 5.4 g of dodecanethiol were mixed to prepare a second mixture. A mixed liquid (dropping liquid) was prepared.

(3) Preparation of reaction liquid After the internal temperature of the first mixed liquid is 5 ° C. or lower, the second mixed liquid is added using the dropping funnel so that the internal temperature does not exceed 10 ° C. over 1 hour to prepare a reaction solution.

(4) Reaction The internal temperature was adjusted to 10°C, and the prepared reaction solution was stirred for 2.5 hours.

(5) Purification (washing with water and alkali washing)
After completion of the reaction, 190 g of a 25% sodium hydroxide aqueous solution was supplied and the temperature was raised to 80°C. After reaching 80° C., the mixture was allowed to stand still, and the lower aqueous phase was extracted. 400 g of demineralized water was added to the obtained first organic phase, mixed for 30 minutes, left to stand, and the aqueous phase was removed. 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained second organic phase, and after confirming that the pH of the lower aqueous phase was 9 or higher, the lower aqueous phase was extracted. 120 g of a 1.5% by mass sodium hydrogencarbonate solution was further added to the obtained third organic phase, and after stirring, the mixture was allowed to stand, and the aqueous phase was extracted. The obtained fourth organic phase was extracted and its mass was measured to be 666 g.

A portion of the fourth organic phase was taken out, and the composition of the fourth organic phase was confirmed by high-performance liquid chromatography. 4% by mass was produced.

(6) Purification (crystallization)
The resulting fourth organic phase was cooled from 80°C to 20°C and maintained at 20°C to precipitate bisphenol C. Then, after cooling to 10°C and reaching 10°C, solid-liquid separation was performed using a centrifuge to obtain a first bisphenol C as a wet cake.
The whole amount of the first bisphenol C and 373 g of toluene were placed in a full-jacket 1 L separable flask equipped with a thermometer and a stirrer, and the temperature was raised to 80°C. After confirming that a uniform fifth organic phase was formed, the fifth organic phase was thoroughly washed with 600 g of desalted water three times, and the aqueous phase was removed. The resulting sixth organic phase was cooled from 80°C to 10°C. After that, filtration was performed using a centrifuge (3000 rpm for 10 minutes) to obtain wet second bisphenol C. Using an evaporator equipped with an oil bath, 163 g of a white third bisphenol C was obtained by distilling off the low-boiling components under reduced pressure at an oil bath temperature of 100°C.

The 190° C. melting color difference of the third bisphenol C obtained was Hazen color number APHA16.

[Example 2]
229 g of ortho-cresol was divided into two parts, and 114.5 g of ortho-cresol in the first mixed solution and 114.5 g of ortho-cresol in the second mixed solution were used to prepare reaction solutions. The purification of (5) (washing with water and alkali washing) was carried out in the same manner as in 1 to obtain 666 g of the fourth organic phase.

The ratio of ortho-cresol in the first mixture (bedding solution) to the total ortho-cresol (bedding solution ratio) was 114.5 g/229 g×100=50%.

A portion of the fourth organic phase was taken out, and the composition of the fourth organic phase was confirmed by high-performance liquid chromatography. 0% by mass was produced.

Furthermore, using the fourth organic phase, (6) Purification (crystallization) of Example 1 was carried out in the same manner as above to obtain 141 g of white third bisphenol C. The 190° C. melting color difference of the obtained third bisphenol C was Hazen color number APHA13.

[Example 3]
Example 1 except that 230 g of ortho-cresol was divided into 174 g and 56 g, and 174 g of ortho-cresol in the first mixed liquid and 56 g of ortho-cresol in the second mixed liquid were used to prepare the reaction liquid. (5) purification (washing with water and alkali washing) was carried out in the same manner as above to obtain 666 g of a fourth organic phase.

The ratio of ortho-cresol in the first mixture (bedding solution) to the total ortho-cresol (bedding solution ratio) was 174 g/230 g×100=76%.

A portion of the fourth organic phase was taken out, and the composition of the fourth organic phase was confirmed by high-performance liquid chromatography. 8% by mass was produced.

Furthermore, using the fourth organic phase, (6) Purification (crystallization) of Example 1 was carried out in the same manner as above to obtain 140 g of white third bisphenol C. The obtained third bisphenol C had a 190° C. melting color difference of Hazen color number APHA10.

[Comparative Example 1]
(5) in the same manner as in Example 1, except that the total amount of 230 g of ortho-cresol was used as ortho-cresol in the second mixture, and the amount of ortho-cresol in the first mixture was 0 g to prepare the reaction mixture. (washing with water and alkali washing) were carried out to obtain 666 g of a fourth organic phase.

The ratio of ortho-cresol in the first mixed solution (bedding solution) to the total ortho-cresol (bedding solution ratio) was 0/230 g x 100 = 0%.

A portion of the fourth organic phase was taken out, and the composition of the fourth organic phase was confirmed by high performance liquid chromatography. 0% by mass was produced.

Furthermore, using the fourth organic phase, (6) Purification (crystallization) of Example 1 was carried out in the same manner as above to obtain 166 g of white third bisphenol C. The obtained third bisphenol C had a 190° C. melting color difference of Hazen color number APHA20.

[Evaluation of MOPC content in the fourth organic phase]
One possible cause of the coloring of bisphenol C is a by-product derived from trimer of acetone. In order to generate a by-product derived from acetone trimer, it is necessary to go through acetone dimer, and the larger the amount of MOPC (by-product derived from acetone dimer), the more It is thought that the by-products of Therefore, the amount of MOPC contained in bisphenol C is considered to be an index of color tone. Therefore, for Examples 1 to 3 and Comparative Example 1, the amount of {2-(4-hydroxy-3-methylphenyl)-2-methylpropyl}methylketone (MOPC amount) in the fourth organic phase was Evaluation was made using ortho-cresol as a reference. Note that {2-(4-hydroxy-3-methylphenyl)-2-methylpropyl}methylketone is a compound represented by the following general formula (5).

The amount of MOPC in the fourth organic phase is the number of moles of MOPC in the fourth organic phase (mass% of MOPC in the fourth organic phase calculated by high performance liquid chromatography × mass of the fourth organic phase 666 [ g]/molecular weight of MOPC (206 [g/mol]) was divided by the number of moles of charged ortho-cresol.
As a result, the amount of MOPC in the fourth organic phase of Example 1 was 0.67 mol% (0.44 mass% x 666 [g]/206 [g/mol]/2.1 [mol] = 0 .67 mol %).
The amount of MOPC in the fourth organic phase of Example 2 was 0.46 mol% (0.30 mass% x 666 [g]/206 [g/mol]/2.1 [mol] = 0.46 mol %)Met.
The amount of MOPC in the fourth organic phase of Example 3 was 0.40 mol% (0.26 mass% xx 666 [g]/206 [g/mol]/2.1 [mol] = 0.40 mol %).
The amount of MOPC in the fourth organic phase of Comparative Example 1 was 1.37 mol% (0.89 mass% x 666 [g]/206 [g/mol]/2.1 [mol] = 1.37 mol %)Met.

Table 1 summarizes the bed liquid ratio, the amount of MOPC in the fourth organic phase, and the Hazen color number of Examples 1 to 3 and Comparative Example 1.
As a result of Table 1, when the total amount of ortho-cresol is mixed with acetone without dividing the ortho-cresol and supplied as a second mixed solution to the first mixed solution containing sulfuric acid, the amount of MOPC in the fourth organic phase is increase. Further, from Table 1, the larger the amount of MOPC in the fourth organic phase, the higher the Hazen color number of bisphenol C, and the amount of MOPC in the fourth organic phase is 1 mol% or less based on the charged ortho-cresol ( 5 mol % or less based on the charged acetone), the Hazen color number tended to decrease.

[Comparative Example 2]
(5) in the same manner as in Example 1 except that the total amount of 230 g of ortho-cresol was used as the ortho-cresol in the first mixture, and the amount of ortho-cresol in the second mixture was 0 g to prepare the reaction mixture. (washing with water and alkali washing) were carried out to obtain 666 g of a fourth organic phase.

The ratio of ortho-cresol in the first mixture (bedding solution) to the total ortho-cresol (bedding solution ratio) was 230 g/230 g×100=100%.

A portion of the fourth organic phase was taken out, and the composition of the fourth organic phase was confirmed by high-performance liquid chromatography. % was generated.

Furthermore, using the fourth organic phase, (6) Purification (crystallization) of Example 1 was carried out in the same manner to obtain 118 g of white third bisphenol C. The 190° C. melting color difference of the third bisphenol C obtained was Hazen color number APHA72.

[Evaluation of unknown components in the fourth organic phase]
For Example 1 and Comparative Example 2, the amount of unknown components in the fourth organic phase was evaluated based on the charged ortho-cresol. The amount of unknown components in the fourth organic phase is from 100 mol% to the amount of ortho-cresol in the fourth organic phase, the amount of bisphenol C in the fourth organic phase, and the amount of MOPC in the fourth organic phase. calculated by subtracting the total.
The amount of ortho-cresol in the fourth organic phase is the number of moles of ortho-cresol (mass% of ortho-cresol in the fourth organic phase calculated by high-performance liquid chromatography × mass of the fourth organic phase 666 [g] /Molecular weight of ortho-cresol 108 [g/mol]) was divided by the number of moles of charged ortho-cresol.
Further, the amount of bisphenol C in the fourth organic phase is obtained by doubling the number of moles of bisphenol C ((mass% of bisphenol C in the fourth organic phase calculated by high performance liquid chromatography × fourth organic phase mass 666 [g]/molecular weight of bisphenol C 256 [g/mol])×2) was divided by the number of moles of charged ortho-cresol.

In Example 1, the amount of ortho-cresol in the fourth organic phase was 21.7 mol % (7.4 mass % x 666 [g]/108 [g/mol]/2.1 [mol] = 21.7 mol%). 7 mol%), and the amount of bisphenol C in the fourth organic phase is 67.9 mol% (27.4 mass% x 666 [g] / 256 [g / mol] / 2.1 [mol] x 2=67.9 mol %) and the amount of MOPC in the fourth organic phase was 0.67 mol %.
As a result, the amount of unknown components in the fourth organic phase of Example 3 is 9.7 mol% (100 mol% - 21.7 mol% - 67.9 mol% - 0.67 mol% = 9.7 mol %).

In Example 2, the amount of ortho-cresol in the fourth organic phase was 21.1 mol% (7.2 mass% x 666 [g]/108 [g/mol]/2.1 [mol] = 21.1 mol%). 1 mol%), and the amount of bisphenol C in the fourth organic phase is 59.5 mol% (24.0% by mass x 666 [g] / 256 [g / mol] / 2.1 [mol] x 2=59.5 mol %) and the amount of MOPC in the fourth organic phase was 0.46 mol %.
As a result, the amount of unknown components in the fourth organic phase of Example 3 is 18.9 mol% (100 mol% - 21.1 mol% - 59.5 mol% - 0.46 mol% = 18.9 mol %).

In Example 3, the amount of ortho-cresol in the fourth organic phase was 20.6 mol% (7.0 mass% x 666 [g]/108 [g/mol]/2.1 [mol] = 20.6 mol%). 6 mol%), and the amount of bisphenol C in the fourth organic phase is 59.0 mol% (23.8 mass% x 666 [g] / 256 [g / mol] / 2.1 [mol] x 2=59.0 mol %) and the amount of MOPC in the fourth organic phase was 0.40 mol %.
As a result, the amount of unknown components in the fourth organic phase of Example 3 was 20.0 mol% (100 mol% - 20.6 mol% - 59.0 mol% - 0.40 mol% = 20.0 mol% mol %).

In Comparative Example 2, the amount of ortho-cresol in the fourth organic phase was 16.2 mol% (5.5 mass% x 666 [g]/108 [g/mol]/2.1 [mol] = 16.2 mol%). 2 mol%), and the amount of bisphenol C in the fourth organic phase is 50.8 mol% (20.5 mass% x 666 [g] / 256 [g / mol] / 2.1 [mol] x 2 = 50.8 mol%), and the amount of MOPC in the fourth organic phase is 0.37 mol% (0.24 mass% × × 666 [g]/206 [g/mol]/2.1 [mol] = 0.37 mol%).
As a result, the amount of unknown components in the fourth organic phase of Comparative Example 2 was 32.6 mol% (100 mol% - 16.2 mol% - 50.8 mol% - 0.37 mol% = 32.63 mol %).

Table 2 summarizes the bed liquid ratio, the amount of unknown components in the fourth organic phase, and the Hazen color number of Examples 1 to 3 and Comparative Example 2.
As a result of Table 2, it can be seen that the amount of unknown components increases when the total amount of ortho-cresol is mixed with sulfuric acid to prepare a first mixed solution without dividing ortho-cresol, and then a mixed solution containing acetone is supplied. . Moreover, it turns out that the amount of unknown components increases, so that a bed liquid rate is high. This unknown component is presumed to be cresol sulfonic acid or the like produced by reaction between sulfuric acid and ortho-cresol.

[Example 4]
100.00 g (0.39 mol) of the third bisphenol C obtained in Example 1, 86.49 g (0.4 mol) of diphenyl carbonate and ) and 479 μL of a 400 mass ppm cesium carbonate aqueous solution were added. The reaction vessel made of glass was evacuated to about 100 Pa, and then the operation of restoring the pressure to atmospheric pressure with nitrogen was repeated three times to replace the inside of the reaction vessel with nitrogen. After that, the reactor was immersed in an oil bath at 200° C. to dissolve the contents.

The rotation speed of the stirrer was set to 100 times per minute, and the pressure in the reaction vessel was increased to absolute pressure over 40 minutes while distilling off the phenol by-product of the oligomerization reaction of bisphenol C and diphenyl carbonate in the reaction vessel. The pressure was reduced from 101.3 kPa to 13.3 kPa.

Subsequently, the pressure in the reactor was maintained at 13.3 kPa, and transesterification was carried out for 80 minutes while further distilling off phenol.

Thereafter, the external temperature of the reaction vessel was raised to 250° C., and the internal pressure of the reaction vessel was reduced from 13.3 kPa to 399 Pa in absolute pressure over 40 minutes to remove distilled phenol out of the system.

Thereafter, the external temperature of the reaction vessel was raised to 280° C., the absolute pressure of the reaction vessel was reduced to 30 Pa, and a polycondensation reaction was carried out. The polycondensation reaction was terminated when the agitator in the reaction tank reached a predetermined stirring power.

Next, the pressure in the reactor was restored to 101.3 kPa in terms of absolute pressure with nitrogen, and then increased to 0.2 MPa in terms of gauge pressure.

After that, the strand was pelletized using a rotary cutter to obtain a polycarbonate resin in the form of pellets.

The polycarbonate had a viscosity average molecular weight (Mv) of 24,900 and a terminal hydroxyl group (OH) concentration of 829 mass ppm. The pellet YI was 12.3.

The method for producing bisphenol of the present invention can produce bisphenol with good color tone. Such bisphenols are useful as raw materials for optical materials such as polycarbonate resins, epoxy resins and aromatic polyester resins.

Claims (6)

In a method for producing bisphenol, the aromatic alcohol and the ketone or aldehyde are reacted in a reaction solution containing an aromatic alcohol, a ketone or aldehyde, and sulfuric acid to obtain bisphenol,
dividing the aromatic alcohol used for the reaction, and supplying a second mixed liquid containing a ketone or aldehyde and the aromatic alcohol to a first mixed liquid containing sulfuric acid and the aromatic alcohol; A reaction liquid preparation step of preparing a reaction liquid;
a reaction step of advancing a bisphenol production reaction after the reaction solution preparation step , and
A method for producing bisphenol, wherein the reaction time in the reaction step is 0.3 hours or longer . The mass ratio of the aromatic alcohol contained in the first mixed liquid to the sum of the aromatic alcohol contained in the first mixed liquid and the aromatic alcohol contained in the second mixed liquid is 0.20 or more and 0 0.90 or less, the method for producing bisphenol according to claim 1. The method for producing bisphenol according to claim 1 or 2, wherein the first mixed solution further contains an organic solvent. 4. The method for producing bisphenol according to claim 3, wherein the organic solvent is an organic solvent containing an aromatic hydrocarbon and an aliphatic alcohol as components . the aromatic alcohol is ortho-cresol,
the ketone or aldehyde is acetone,
The method for producing bisphenol according to any one of claims 1 to 4, wherein the bisphenol is 2,2-bis(4-hydroxy-3-methylphenyl)propane. A method for producing a polycarbonate resin, comprising producing a polycarbonate using bisphenol produced by the method for producing bisphenol according to any one of claims 1 to 5.