JP7087848B2 - 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 an aldehyde or a ketone, and a method for producing a polycarbonate resin using the obtained bisphenol.
The bisphenol produced by the method of the present invention contains resin raw materials such as polycarbonate resin, epoxy resin, and aromatic polyester resin, and addition of a curing agent, a color developer, a fading inhibitor, and other bactericidal agents and antibacterial and antifungal agents. It is useful as an agent.

Bisphenol is useful as a raw material for polymer materials such as polycarbonate resin, epoxy resin, and aromatic polyester resin. As typical bisphenols, for example, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane and the like are known (Patent Document 1). Further, the production of tetramethylbisphenol F having an aqueous phase electrical conductivity of 10 μS / cm or less at 25 ° C. when a solution of tetramethylbisphenol F dissolved in 20 times the weight of toluene is extracted with 1 time the amount of pure water. The method is known (Patent Document 2).

Japanese Unexamined Patent Publication No. 62-138443 Japanese Unexamined Patent Publication No. 2002-187682

In the production of polycarbonate resin, a very small amount of catalyst is used for the raw material bisphenol. Therefore, since the trace amount of acid component and basic component contained in the raw material bisphenol affects the polymerization reaction for producing the polycarbonate resin, it is possible to control the amount of the trace amount of acid component and basic component contained in the raw material bisphenol. is important. Further, since the color tone of the raw material bisphenol affects the color tone of the obtained polycarbonate resin, it is necessary to control the color tone of the bisphenol.

The present inventors produced 2,2-bis (4-hydroxy-3-methylphenyl) propane by the method described in Patent Document 1 and Patent Document 2, and obtained 2,2-bis (4-hydroxy-). When a polycarbonate resin was produced by a melt polymerization reaction using 3-methylphenyl) propane, there were problems that the melt polymerization reaction took longer than expected and that the target molecular weight could not be achieved. there were. Further, regarding the color tone of the obtained bisphenol, the melt color difference (the number of Hazen colors) was high, and the color tone of the polycarbonate resin obtained by using this was also inferior (high pellet YI).

As described above, in the conventional method, it is not easy to obtain bisphenol which can efficiently carry out the polymerization reaction as a raw material for producing a polycarbonate resin and can produce a polycarbonate resin having a good color tone itself and having a good color tone. , The improvement was required.

The present invention relates to a method for producing bisphenol, which has a good color tone, can efficiently proceed with a polymerization reaction as a raw material for a polycarbonate resin, and can produce a polycarbonate resin having a good color tone, and a polycarbonate resin using the bisphenol. It is an object to provide a manufacturing method of.

As a result of diligent studies to solve the above problems, the present inventors have conducted intensive studies to purify bisphenol produced by using an acid catalyst and a thiol co-catalyst in a washing step and a crystallization step, and as a result, the pH of the aqueous phase used for washing. By controlling the electrical conductivity, it is possible to produce bisphenol with a good melt color difference. By using the bisphenol produced by this method, the polymerization time is short and the pellet YI can be produced in an efficient polymerization reaction. They have found that a low polycarbonate resin can be produced, and have completed the present invention.

That is, the gist of the present invention lies in the following [1] to [4].

[1] In the presence of an acid catalyst and thiol, a reaction step of condensing a ketone or aldehyde with an aromatic alcohol to obtain bisphenol, a washing step of washing the obtained bisphenol, and a crystallization step of precipitating bisphenol. In the method for producing bisphenol having the above, in the washing step, after mixing the organic phase (O1) containing bisphenol and desalted water, the phase is separated into the organic phase (O2) containing bisphenol and the aqueous phase (W1). Then, the first step of removing the aqueous phase (W1) to obtain the organic phase (O2) containing the bisphenol, the organic phase (O2) containing the bisphenol obtained in the first step, and the desalted water After mixing, the phase is separated into an organic phase (O3) containing bisphenol and an aqueous phase (W2), and the aqueous phase (W2) is removed to obtain an organic phase (O3) containing the bisphenol. The aqueous phase (W1) has a pH of 8.5 or more, the electric conductivity of the aqueous phase (W2) is 10 μS / cm or less, and the organic phase (O3) has undergone the washing step. ) Is subjected to the crystallization step, a method for producing bisphenol.

[2] The method for producing bisphenol according to [1], wherein the acid catalyst is sulfuric acid or hydrogen chloride.

[3] The method for producing bisphenol according to [1] or [2], wherein the bisphenol is 2,2-bis (4-hydroxy-3-methylphenyl) propane.

[4] A method for producing a polycarbonate resin using bisphenol produced by the method for producing bisphenol according to any one of [1] to [3].

By the method for producing bisphenol of the present invention, it is possible to obtain bisphenol having a good melt color difference, and by using the obtained bisphenol, a polycarbonate resin having a good color tone can be obtained by a short polymerization time and an efficient polymerization reaction. Can be manufactured.

Hereinafter, embodiments of the present invention will be described in detail, but the description of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is described below as long as the gist of the present invention is not exceeded. Not limited to.
In addition, when the expression "-" is used in this specification, it shall be used as an expression including numerical values or physical property values before and after the expression.

[Manufacturing method of bisphenol]
First, an embodiment of the method for producing bisphenol of the present invention will be described in detail.
In the method for producing bisphenol of the present invention, bisphenol is produced by condensing an aromatic alcohol with a ketone or aldehyde using an acid catalyst such as sulfuric acid and thiol as a co-catalyst (reaction accelerator) (reaction step). In purifying the produced bisphenol in a washing step and a crystallization step, it is characterized in that the pH and electrical conductivity of the aqueous phase of the washing water in the washing step are controlled.

[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).

In the general formula (1), examples of R ¹ to R ⁴ include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, and an aryl group, respectively. The alkyl group, alkoxy group, aryl group and the like may be substituted or unsubstituted. Examples of R ¹ to R ⁴ include hydrogen atom, fluoro group, chloro group, bromo group, iodine group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group and 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 can be mentioned.

Of these, R ² and R ³ are preferably hydrogen atoms because the condensation reaction does not easily proceed if they are sterically bulky. Further, it is more preferable that R ¹ to R ⁴ are independently hydrogen atoms or alkyl groups, respectively, R ¹ and R ⁴ are independently hydrogen atoms or alkyl groups, and R ² and R ³ are hydrogen atoms. Is even more preferable.

Specific examples of the compound represented by the general formula (1) include phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol, methoxyphenol, ethoxyphenol, propoxyphenol, butoxyphenol, benzylphenol, and phenylphenol. Can be mentioned.

Among them, any one selected from the group consisting of phenol, cresol, and xylenol is preferable, cresol or xylenol is more preferable, and cresol is further preferable.

[Ketone or aldehyde]
The ketone or aldehyde used in the production method of the present invention is usually a compound represented by the following general formula (2).

In the general formula (2), examples of R ⁵ and R ⁶ include a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and the like, respectively. The alkyl group, alkoxy group, aryl group and the like may be substituted or unsubstituted. For example, 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-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, Examples thereof include a benzyl group, a phenyl group, a trill group and a 2,6-dimethylphenyl group.

R ⁵ and R ⁶ may be bonded or crosslinked with each other between the two groups, or R ⁵ and R ⁶ may be bonded together with an adjacent carbon atom to contain a heteroatom. An alkylidene group may be formed. The cycloalkylidene group is a divalent group obtained by removing two hydrogen atoms from one carbon atom of cycloalkane.

Examples of the cycloalkylidene group formed by bonding R5 and ^R6 together with adjacent carbon atoms include cyclopropyridene, cyclobutylidene, cyclopentylidene, cyclohexylidene, 3,3,5 ^- trimethyl. Cyclohexylidene, cycloheptylidene, cyclooctylidene, cyclononilidene, cyclodecylidene, cycloundecylidene, cyclododecylidene, fluorenilidene, xantonilidene, thioxanthonilidene and the like can be mentioned.

Specific examples of the compound represented by the general formula (2) include formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, pentylaldehyde, hexylaldehyde, heptylaldehyde, octylaldehyde, nonylaldehyde, decylaldehyde, and undecylaldehyde. Aldehydes such as dodecylaldehyde, acetone, butanone, pentanon, hexanone, heptanone, octanon, nonanone, decanone, undecanone, dodecanone and other ketones, benzaldehyde, phenylmethylketone, phenylethylketone, phenylpropylketone, cresylmethylketone, Arylalkylketones such as cresylethylketone, cresylpropylketone, xylylmethylketone, xylylethylketone, xylylpropylketone, cyclopropanol, cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, Cyclic alkhanketones such as cyclononanone, cyclodecanone, cycloundecanone, and cyclododecanone can be mentioned. Of these, acetone is preferable.

When the molar ratio of aromatic alcohol to ketone or aldehyde used for condensation ((number of moles of aromatic alcohol / number of moles of ketone) or (number of moles of aromatic alcohol / number of moles with aldehyde)) is low, the number of ketones or aldehydes is low. Since a large amount of the self-condensation reaction product of the above is by-produced, 1.0 or more is preferable, 1.2 or more is more preferable, and 1.5 or more is further preferable. Further, when the molar ratio is high, it takes time to recover the unreacted aromatic alcohol, so that it is preferably 20 or less, more preferably 15 or less, still more preferably 10 or less.

[Acid catalyst]
Examples of the acid catalyst used in the production method of the present invention include aromatic sulfonic acids such as sulfuric acid, hydrochloric acid, hydrogen chloride gas, phosphoric acid and p-toluene sulfonic acid, and aliphatic sulfonic acids such as methane sulfonic acid.

If the molar ratio of the acid catalyst to the ketone or aldehyde used for condensation ((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, as the condensation reaction progresses. The acid catalyst is diluted by the by-produced water and the reaction takes time. In addition, in the case of a large amount, the increase in the amount of ketone or aldehyde may proceed. From these facts, the molar ratio of the acid catalyst to the ketone or aldehyde used for condensation is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.1 or more. The upper limit thereof is preferably 10 or less, more preferably 8 or less, and further preferably 5 or less.

The acid catalyst is preferably any one selected from the group consisting of sulfuric acid, hydrochloric acid, and hydrogen chloride gas, and more preferably sulfuric acid and / or hydrogen chloride gas. In particular, sulfuric acid is preferable as the acid catalyst from the viewpoints of excellent reaction efficiency, no volatility of the catalyst, and less burden on equipment.

Sulfuric acid is an acidic liquid represented by the chemical formula H ₂ SO ₄ . Generally, sulfuric acid is used as an aqueous solution of sulfuric acid 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 sulfuric acid aqueous solution) is low, the amount of water increases, so that the reaction for producing bisphenol becomes difficult to proceed, the reaction time for producing bisphenol becomes long, and bisphenol can be produced efficiently. May be difficult. Therefore, the concentration of sulfuric acid used is preferably 70% by mass or more, more preferably 75% by mass or more, and further preferably 80% by mass or more. 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]
In the present invention, a thiol is used as a co-catalyst in the reaction of condensing a ketone or aldehyde with an aromatic alcohol.
By using thiol as a co-catalyst, for example, in the production of 2,2-bis (4-hydroxy-3-methylphenyl) propane, the production of 24 bodies is suppressed, the selectivity of 44 bodies is increased, and the polycarbonate resin is manufactured. The effect of increasing the polymerization activity at the time and improving the color tone of the obtained polycarbonate resin can be obtained. Although the details of the reason why the effect of improving the polymerization activity during the production of the polycarbonate resin and the effect of improving the color tone of the obtained polycarbonate resin are exhibited are not clear, the use of thiol is an inhibitor of the polymerization reaction for producing the polycarbonate resin. It is presumed that this is due to the fact that it is possible to suppress the production and the production of color-deteriorating substances.

Examples of the thiol used as a co-catalyst include mercaptocarboxylic acids such as mercaptoacetic acid, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid and 4-mercaptobutyric acid, and methyl mercaptan, ethyl mercaptan, propyl mercaptan and butyl. Mercaptan, Pentyl mercaptan, Hexyl mercaptan, Heptil mercaptan, Octyl mercaptan, Nonyl mercaptan, Decyl mercaptan (decantyl), Undecyl mercaptan (undecanthir), Dodecyl mercaptan (dodecanthyl), Tridecyl mercaptan, Tetradecyl mercaptan, Tetradecyl mercaptan Examples thereof include alkyl thiols such as decyl mercaptan and aryl thiols such as mercaptophenol.

If the molar ratio of the thiol cocatalyst to the ketone or aldehyde used for condensation ((number of moles of thiol cocatalyst / number of moles of ketone) or (number of moles of thiol cocatalyst / number of moles of aldehyde)) is small, the thiol cocatalyst is used. The effect of improving the reaction selectivity of bisphenol by using it cannot be obtained, and if it is too much, it may be mixed with bisphenol and the quality may be deteriorated. From these facts, the lower limit of the molar ratio of the thiol co-catalyst to the ketone and the aldehyde is preferably 0.001 or more, more preferably 0.005 or more, still more preferably 0.01 or more. The upper limit thereof is preferably 1 or less, more preferably 0.5 or less, still more preferably 0.1 or less.

The thiol cocatalyst is preferably premixed with a ketone or aldehyde before being subjected to the reaction. As a method of mixing a thiol with a ketone or an aldehyde, a ketone or an aldehyde may be mixed with the thiol, or a thiol may be mixed with the ketone or the aldehyde. Further, as a method of mixing a mixed solution of thiol and a ketone or aldehyde and an acid catalyst, an acid catalyst may be mixed with a mixed solution of thiol and a ketone or aldehyde, and the acid catalyst is mixed with thiol and a ketone or aldehyde. A mixed solution may be mixed, but it is preferable to mix a mixed solution of thiol and a ketone or aldehyde with an acid catalyst. Further, it is more preferable to supply the acid catalyst and the aromatic alcohol to the reaction vessel, and then supply the mixed solution of the thiol to the ketone or aldehyde to the reaction vessel for mixing.

[Organic solvent]
In the method for producing bisphenol of the present invention, an organic solvent is usually used to dissolve or disperse the produced bisphenol.
The organic solvent is not particularly limited as long as it does not inhibit the reaction of producing bisphenol, and examples thereof include aromatic hydrocarbons, aliphatic alcohols, and aliphatic hydrocarbons (here, aromatic alcohol as a substrate and production). Bisphenol, which is a substance, is excluded from organic solvents.) These solvents may be used alone or in combination of two or more.

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

The aliphatic alcohol is an alkyl alcohol in which an alkyl group and a hydroxyl group are bonded. The fatty alcohol may be a monohydric fatty alcohol in which an alkyl group and one hydroxyl group are bonded, or may be a polyhydric fatty alcohol in which an alkyl group and two or more hydroxyl groups are bonded. Further, the alkyl group may be linear or branched, may be unsubstituted, or a part of the carbon atom of the alkyl group may be substituted with an oxygen atom.

As the number of carbon atoms increases, the lipophilicity of the aliphatic alcohol increases, it becomes difficult to mix with sulfuric acid, and it becomes difficult to generate monoalkyl sulfate, which will be described later. Therefore, the number of carbon atoms is preferably 12 or less, preferably 8 or less. More preferred.

Further, the aliphatic alcohol is preferably an alcohol in which an alkyl group and one hydroxyl group are bonded, and more preferably an alcohol in which an alkyl group having 1 to 8 carbon atoms and one hydroxyl group are bonded. An alcohol in which an alkyl group having 1 to 5 carbon atoms and one hydroxyl group are bonded is more preferable.

Specific fatty 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 glucol, triethylene glycol and the like can be mentioned. One of the preferred aliphatic alcohols is methanol.

Examples of the aliphatic hydrocarbons include linear hydrocarbons having 5 to 18 carbon atoms such as n-pentane, n-hexane, n-heptane, and n-octane, and branched chain hydrocarbons having 5 to 18 carbon atoms such as isooctane. , Cyclohexane, cyclooctane, methylcyclohexane and other cyclic hydrocarbons having 5 to 18 carbon atoms.

If the mass ratio of the organic solvent to the ketone or aldehyde used for condensation ((mass of ketone / mass of organic solvent) or (mass of aldehyde / mass of organic solvent)) is too large, the ketone or aldehyde and the aromatic alcohol Is difficult to react and it takes a long time to react. If the amount is too small, the increase in the amount of ketones or aldehydes may be promoted, or the bisphenol produced may solidify. From these facts, the mass ratio of the organic solvent to the ketone or aldehyde at the time of charging is preferably 0.5 or more, more preferably 1 or more. The upper limit thereof is preferably 100 or less, more preferably 50 or less.

It is more difficult for bisphenol to decompose when the generated bisphenol is dispersed without being completely dissolved in an organic solvent. Further, it is preferable to use a solvent having a low solubility of bisphenol because the loss in recovering bisphenol from the reaction solution (for example, the loss in the filtrate at the time of crystallization) can be reduced after the reaction is completed. Examples of the solvent having a low solubility of bisphenol include aromatic hydrocarbons. Therefore, the organic solvent preferably contains an aromatic hydrocarbon as a main component, preferably contains 55% by mass or more of the aromatic hydrocarbon in the organic solvent, more preferably 70% by mass or more, and more preferably 80% by mass. It is more preferable to contain% or more.

When the acid catalyst contains sulfuric acid, the organic solvent contains an aliphatic alcohol, so that the sulfuric acid reacts with the aliphatic alcohol to produce monoalkyl sulfate, and this monoalkyl sulfate can also obtain catalytic action. The effect is obtained. Therefore, when the acid catalyst contains sulfuric acid, the organic solvent is preferably an organic solvent containing an aliphatic alcohol. Further, as the fatty alcohol has a large number of carbon atoms, the lipophilicity increases, it becomes difficult to mix with sulfuric acid, and it becomes difficult to generate monoalkyl sulfate. Therefore, an alkyl alcohol having 8 or less carbon atoms is preferable.
In this way, by reacting sulfuric acid with an aliphatic alcohol to generate monoalkyl sulfate, the acid strength of the acid catalyst can be controlled, and condensation (enlargement) and coloring of the raw material ketone or aldehyde can be suppressed. .. Therefore, it becomes possible to easily and efficiently produce bisphenol in which the formation of by-products is suppressed and the coloring is reduced.

When sulfuric acid is reacted with an aliphatic alcohol to generate monoalkyl sulfate and its catalytic action is also used, if the molar ratio of the aliphatic alcohol to sulfuric acid (the number of moles of the aliphatic alcohol / the number of moles of the sulfuric acid) is small, the raw material is Condensation (enhancement) and coloring of the ketone or aldehyde of the above becomes remarkable. On the other hand, if it is too high, the sulfuric acid concentration will decrease and the reaction will be slowed down. From these facts, the lower limit of the molar ratio of the aliphatic alcohol to sulfuric acid is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.1 or more. The upper limit thereof is preferably 10 or less, more preferably 5 or less, and further preferably 3 or less.

From the above, the organic solvent can contain, for example, aromatic hydrocarbons and fatty alcohols, and the organic solvent contains 1 to 95% by mass of aromatic hydrocarbons and 0.1 to 10 fatty alcohols. It may contain% by mass.

[Condensation reaction between ketones or aldehydes and aromatic alcohols]
In the method for producing bisphenol of the present invention, bisphenol represented by the following general formula (4) is produced by condensation of a ketone or aldehyde with an aromatic alcohol according to the reaction formula (3) shown below.

（式中、Ｒ^１～Ｒ^６は、一般式（１）及び（２）におけるものと同義である。）

(In the formula, R ¹ to R ⁶ are synonymous with those in the general formulas (1) and (2).)

（式中、Ｒ^１～Ｒ^６は、一般式（１）及び（２）におけるものと同義である。）

(In the formula, R ¹ to R ⁶ are synonymous with those in the general formulas (1) and (2).)

Specific examples of the bisphenol represented by the general formula (4) include 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, and 2, 2-bis (4-hydroxy-3,5-dimethylphenyl) 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-hydroxy) Phenyl) heptane, 2,2-bis (4-hydroxy-3-methylphenyl) heptane, 4,4-bis (4-hydroxyphenyl) heptane, 4,4-bis (4-hydroxy-3-methylphenyl) heptane However, it is not limited to these.

Among these, the method for producing bisphenol of the present invention is used for producing 2,2-bis (4-hydroxy-3-methylphenyl) propane or 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane. It is suitable, and particularly suitable for the production of 2,2-bis (4-hydroxy-3-methylphenyl) propane (bisphenol C).

The method for preparing the reaction solution is not particularly limited, and a method of supplying an acid catalyst to a mixed solution of a mixture of an aromatic alcohol, an organic solvent, a ketone or an aldehyde, or a method of mixing an acid catalyst, an aromatic alcohol and an organic solvent. Examples thereof include a method of supplying a ketone or an aldehyde to the mixed solution.

In order to suppress the increase in the amount of ketone or aldehyde due to self-condensation, it is preferable to mix a solution containing an aromatic alcohol, an acid catalyst and an organic solvent with a solution containing a ketone or aldehyde. In this case, the solution containing the ketone or aldehyde may contain the ketone or aldehyde alone, or may contain a thiol or an organic solvent. Solutions containing ketones or aldehydes preferably contain thiols.

In the method for producing bisphenol of the present invention, the reaction for producing bisphenol is a condensation reaction between a ketone or an aldehyde and an aromatic alcohol. When the reaction temperature of the condensation reaction is high, the amount of ketone or aldehyde tends to increase, and when the temperature is low, the time required for the reaction becomes long. From these facts, the lower limit of the reaction temperature is preferably −30 ° C. or higher, more preferably −20 ° C. or higher, still more preferably −15 ° C. or higher. The upper limit of the reaction temperature is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, still more preferably 70 ° C. or lower.

In the method for producing bisphenol of the present invention, the reaction time of the condensation reaction is appropriately adjusted according to the reaction conditions such as the type of bisphenol to be produced and the reaction temperature. When the reaction time is long, the produced bisphenol is decomposed, so that it is preferably 30 hours or less, more preferably 25 hours or less, still more preferably 20 hours or less. The lower limit of the reaction time is usually 0.5 hours or more, and may be 1 hour or more.
The reaction time also includes the mixing time of the ketone or aldehyde and the aromatic alcohol. For example, when a mixed solution of an aromatic alcohol and an acid catalyst is supplied with a ketone or aldehyde over 1 hour and then reacted for 1 hour, the reaction time is 2 hours.
Further, the reaction can be stopped by adding water or a base in an amount equal to or more than that of the acid catalyst used to reduce the acid catalyst concentration.

[Refining process]
In the method for producing bisphenol of the present invention, the bisphenol obtained by the condensation reaction is washed in the washing step and then precipitated and purified in the crystallization step.
That is, after the condensation reaction, the organic phase containing bisphenol obtained from the reaction solution is washed with desalinated water, and the washed organic phase is cooled and crystallized. Wash multiple times as follows. Crystallization may also be performed a plurality of times.
When a large amount of aromatic alcohol is used in the condensation reaction, excess aromatic alcohol may be distilled off before crystallization and then crystallization may occur.
Usually, prior to the purification step according to the present invention, the bisphenol obtained by the reaction is crudely purified by performing the crude purification step described later, and the crude bisphenol is subjected to the purification step according to the present invention.

<Washing process>
In the cleaning step according to the present invention, the organic phase (O1) containing bisphenol obtained from the reaction step, preferably bisphenol undergoing the crude purification step described later, and desalted water are mixed, and then the organic phase containing bisphenol (O2) is mixed. ) And the aqueous phase (W1), the aqueous phase (W1) is removed, and the organic phase (O2) containing bisphenol is obtained in the first step (first water washing step) and the first step. After mixing the organic phase (O2) containing bisphenol and desalted water, the organic phase (O3) containing bisphenol and the aqueous phase (W2) are phase-separated to remove the aqueous phase (W2), and the bisphenol is removed. The second step (second water washing step) for obtaining the contained organic phase (O3) is performed at least, and the first step is performed so that the pH of the aqueous phase (W1) is 8.5 or more, and the aqueous phase (W2) is obtained. The second step is performed so that the electric conductivity of the above is 10 μS / cm.
Here, the demineralized water is water that has undergone ion exchange treatment, pure water, or the like, and has an electrical conductivity of 2 μS / cm or less.

The pH measurement conditions of the aqueous phase (W1) in the first step are as follows.
Usually, after washing the organic phase containing bisphenol in the washing step, the temperature is lowered in the crystallization step to precipitate bisphenol. Therefore, the temperature at the time of washing is room temperature (20 to 30 ° C.) or higher. Since the pH changes depending on the temperature, the measured temperature is preferably room temperature (20 to 30 ° C.), for example 25 ° C. Further, the pH may be measured at the time of mixing oil and water in the washing tank, or may be measured for the aqueous phase obtained by statically separating after mixing the oil and water in the washing tank, and the water extracted from the washing tank after washing may be measured. Although the phase may be measured, it is preferable to measure the pH of the aqueous phase extracted from the washing tank after washing and static separation from the viewpoint of easily lowering the measurement temperature.

When the pH of the aqueous phase is lower than 7, the washing can be performed with a basic substance such as sodium hydroxide or sodium hydrogen carbonate, and the washing can be performed again with water. The organic phase obtained after washing with a basic substance is washed again with water so that the pH of the water phase becomes 8.5 or higher. Here, if the basicity of the aqueous phase (W1) is weak (low pH), the cleaning effect is low and the effect of the present invention cannot be obtained. Therefore, the pH is 8.5 or higher, preferably 9 or higher. On the other hand, if the aqueous phase (W1) is strongly basic (high pH), bisphenol becomes a bisphenol salt and the amount of loss in washing with water increases. Therefore, the upper limit of the pH of the aqueous phase (W1) is usually 14 or less. It is preferably 13 or less, and more preferably 12 or less.

The measurement of the electric conductivity of the aqueous phase (W2) in the second step is as follows.
Since the electrical conductivity changes depending on the measurement temperature, the measurement temperature is preferably room temperature (20 to 30 ° C.), for example, 25 ° C., as in the case of pH measurement. Further, the electric conductivity may be measured at the time of mixing oil and water in the washing tank, or may be measured for the aqueous phase obtained by statically separating after mixing the oil and water in the washing tank, and may be taken out from the washing tank after washing. The aqueous phase may be measured, but from the viewpoint of easily lowering the measurement temperature, it is preferable to measure the electrical conductivity of the aqueous phase extracted from the washing tank after washing and static separation.
Cleaning is performed so that the electric conductivity of the aqueous phase (W2) in the second step is 10 μS / cm or less, but the electric conductivity of the aqueous phase (W2) in the second step is preferably 9 μS / cm or less. More preferably, it is 8 μS / cm or less.

In the method for producing bisphenol of the present invention, in the washing step, the organic phase containing bisphenol is first washed with water so that the pH of the obtained aqueous phase becomes basic with a pH of 8.5 or more, and then washing with water is repeated as necessary. When the electric conductivity of the obtained aqueous phase is 10 μS / cm or less, it is preferable to perform the crystallization step.

Generated by washing with demineralized water so that the pH of the aqueous phase (W1) in the first water washing step becomes equal to or higher than the above lower limit and the electrical conductivity of the aqueous phase (W2) in the second washing step becomes equal to or lower than the above upper limit. Polycarbonate resin that has good hue by highly removing impurities such as by-products, residual catalyst, and residual thiol in bisphenol, and has high polymerization reaction efficiency and excellent hue when used as a raw material bisphenol for polycarbonate resin. Can be obtained from bisphenols that can be produced. In particular, in the condensation reaction using thiol as a co-catalyst, acidic thionium is produced from the thiol, which is contained in bisphenol and inhibits the polymerization reaction during the production of the polycarbonate resin. By performing a cleaning step in which the pH and the electrical conductivity of the aqueous phase (W2) are controlled, thionium can be efficiently removed and polymerization inhibition by thionium can be prevented.

The organic phase (O1) to be used in this washing step is preferably dissolved or dispersed in an organic solvent so that the bisphenol concentration is 5 to 70% by mass, particularly about 10 to 60% by mass. If the bisphenol concentration of the organic phase (O1) is at least the above lower limit, the recovery efficiency of bisphenol is not impaired, and if it is at least the above upper limit, the cleaning efficiency can be increased. Here, as the organic solvent used, the same one as the reaction solvent used for the condensation reaction can be used, and toluene is preferable.

Further, the amount of demineralized water used in one washing operation should be 0.001 to 100 times by mass, particularly 0.01 to 10 times by mass, as compared with the organic phase to be washed with water, in order to improve the washing efficiency and work efficiency. Preferred from the viewpoint.

The temperature in the washing step is preferably 90 to 50 ° C., particularly 85 to 55 ° C. so that bisphenol can be efficiently precipitated by cooling in the crystallization step described later without evaporating the solvent. .. The cleaning time (time for adding desalinated water to the organic phase and mixing) is usually about 1 to 120 minutes.

<Crystalization process>
The organic phase (O3) obtained in the above-mentioned washing step is mainly composed of bisphenol and an organic solvent, and high-purity purified bisphenol can be precipitated by cooling in the crystallization step.

The cooling temperature in this crystallization step is 10 to 120 ° C. lower than the temperature of the organic phase (O3) obtained from the washing step, and is preferably 40 to -20 ° C., particularly preferably about 30 to -10 ° C. By cooling the washed organic phase (O3) to such a temperature, bisphenol can be efficiently precipitated.

The bisphenol precipitated in the crystallization step can be recovered by solid-liquid separation by filtration, centrifugation, decantation or the like.

Although the crystallization step of dissolving the recovered bisphenol in an organic solvent again and precipitating it may be performed a plurality of times, in the present invention, the bisphenol can be highly purified in the above-mentioned washing step, so that it is a normal crystal. In many cases, the crystallization step may be a single crystallization operation.

The bisphenol precipitated in the crystallization step and recovered by solid-liquid separation may be subjected to desolvation treatment by heating, reduced pressure, air drying or the like, if necessary, to obtain bisphenol substantially free of solvent.
Further, in order to improve the handleability, the powder properties may be controlled by pulverizing or classifying.

[Rough purification process]
Prior to the above purification step, in the method for producing bisphenol of the present invention, an acid catalyst removing step of removing the acid catalyst by neutralizing the reaction solution containing the bisphenol produced by the condensation reaction with an alkali, and removing the acid catalyst. After that, a concentration step of concentrating the bisphenol, an organic phase adjusting step of adding an organic catalyst to the concentrated bisphenol to prepare an organic phase (O1) to be used for washing may be performed. As the organic solvent used here, the same solvent as the reaction solvent used for the condensation reaction can be used, and the bisphenol concentration of the organic phase (O1) used in the washing step is about 5 to 70% by mass, particularly about 10 to 60% by mass. Is preferable. If the bisphenol concentration of the organic phase (O1) is at least the above lower limit, the recovery efficiency of bisphenol is not impaired, and if it is at least the above upper limit, the cleaning efficiency can be increased.

[Use of bisphenol]
The bisphenol obtained by the method for producing bisphenol of the present invention (hereinafter, may be referred to as "bisphenol of the present invention") includes optical materials, recording materials, insulating materials, transparent materials, electronic materials, adhesive materials, heat-resistant materials and the like. Various thermoplastic resins such as polyether resin, polyester resin, polyarylate resin, polycarbonate resin, polyurethane resin, acrylic resin used for various purposes, epoxy resin, unsaturated polyester resin, phenol resin, polybenzoxazine resin, It can be used as a constituent component of various thermosetting resins such as cyanate resin, a curing agent, an additive, or a precursor thereof. It is also useful as an additive such as a color developer such as a heat-sensitive recording material, a fading inhibitor, a bactericidal agent, and an antibacterial and antifungal agent.

Of these, it is preferable to use it as a raw material (monomer) for a thermoplastic resin or a thermosetting resin because it can impart good mechanical properties, and it is more preferable to use it as a raw material for a polycarbonate resin or an epoxy resin. It is also preferable to use it as a color developer, and it is more preferable to use it in combination with a leuco dye and a color change temperature adjusting agent.

[Manufacturing method of polycarbonate resin]
Next, a method for producing a polycarbonate resin using the bisphenol of the present invention as a raw material will be described.

The method for producing a polycarbonate resin using bisphenol of the present invention as a raw material is a transesterification reaction of the bisphenol of the present invention and a carbonic acid diester such as diphenyl carbonate, for example, in the presence of an alkali metal compound and / or an alkaline earth metal compound. It is a method of manufacturing by a method of making it. The transesterification reaction can be carried out by appropriately selecting a known method, and an example of a method for producing a polycarbonate resin using bisphenol and diphenyl carbonate as raw materials of the present invention will be described below.

In the above method for producing a polycarbonate resin, it is preferable to use diphenyl carbonate in an excess amount with respect to the bisphenol of the present invention. The amount of diphenyl carbonate used for bisphenol is preferably large in that the produced polycarbonate resin has few terminal hydroxyl groups and is excellent in thermal stability of the polymer, and the transesterification reaction rate is high, and the polycarbonate having a desired molecular weight is used. It is preferable that the amount is small in terms of easy production of the resin. From these facts, the amount of diphenyl carbonate used per 1 mol of bisphenol is usually 1.001 mol or more, preferably 1.002 mol or more. Further, it is usually 1.3 mol or less, preferably 1.2 mol or less.

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

When producing a polycarbonate resin by transesterification reaction of diphenyl carbonate and bisphenol, a transesterification catalyst is usually used. In the above method for producing a 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, it is desirable to use an alkali metal compound.

The amount of transesterification catalyst used for 1 mol of bisphenol or diphenyl carbonate is usually 0.05 μmol or more, preferably 0.08 μmol or more, and more preferably 0.10 μmol or more. Further, it is usually 100 μmol or less, preferably 50 μmol or less, and more preferably 20 μmol or less.

When the amount of the transesterification catalyst used is within the above range, it is easy to obtain the polymerization activity required for producing a polycarbonate resin having a desired molecular weight, the hue is excellent, and excessive polymer branching does not proceed. , It is easy to obtain a polycarbonate resin having excellent fluidity during molding.

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

In the production of the polycarbonate resin using the bisphenol of the present invention, the polymerization reaction temperature is preferably 80 to 400 ° C, particularly preferably 150 to 350 ° C. The polymerization time is appropriately adjusted depending on the ratio of raw materials, the desired molecular weight of the polycarbonate resin, etc., but if the polymerization time is long, quality deterioration such as deterioration of color tone becomes apparent, so it may be 10 hours or less. It is preferably 8 hours or less, and more preferably 8 hours or less. The lower limit of the polymerization time is usually 0.1 hours or more, or 0.3 hours or more.

Since the bisphenol of the present invention has excellent polymerization activity, it is possible to efficiently produce a polycarbonate resin having a large molecular weight. Further, since the bisphenol of the present invention has a good hue, it is possible to produce a polycarbonate resin having excellent transparency. For example, a polycarbonate resin having a viscosity average molecular weight (Mv) of 10,000 to 100,000 and having a pellet YI of 20 or less and excellent transparency can be produced in a short time.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

[Raw materials and reagents]
In the following examples and comparative examples, orthocresol, toluene, sodium hydroxide, sulfuric acid, dodecanethiol, methanol, acetone, sodium hydrogencarbonate, ethyl mercaptan, and cesium carbonate are reagents manufactured by Fuji Film Wako Pure Chemical Industries, Ltd. used.
As diphenyl carbonate, a product manufactured by Mitsubishi Chemical Corporation was used.
As the hydrogen chloride gas, a product of Sumitomo Seika Chemical Co., Ltd. was used.

[Analysis / Measurement]
<Quantitative analysis of cresol and bisphenol C>
Quantitative analysis of cresol and bisphenol C was performed by high performance liquid chromatography under the following procedure and conditions.
Equipment: LC-2010A manufactured by Shimadzu Corporation
Imtaket ScherzoSM-C18 3μm 150mm x 4.6mm ID
Analysis temperature: 40 ° C
Eluent composition:
Solution A Ammonium acetate: Acetic acid: Dechlorinated water = 3.000 g: 1 mL: 1 mL solution Solution B Ammonium acetate: Acetic acid: Acetonitrile = 1.500 g: 1 mL: 900 mL solution Low-pressure gradient method:
When the analysis time is 0 minutes, liquid A: liquid B = 60:40 (volume ratio, the same applies hereinafter).
During the analysis time of 0 to 25 minutes, the eluent composition was gradually changed to solution A: solution B = 90:10.
Analysis time 25 to 30 minutes is maintained at solution A: solution B = 90:10 Flow rate 0.8 mL / min Detection wavelength: 280 nm

<Measurement of pH>
The pH was measured using a pH meter pH METER ES-73 manufactured by HORIBA, Ltd. for an aqueous phase at 25 ° C. taken out from the flask.

<Electrical conductivity>
The measurement of the electric conductivity was carried out using an electric conductivity meter COND METER D-71 manufactured by HORIBA, Ltd. for an aqueous phase at 25 ° C. taken out from the flask.

<Melted color difference of bisphenol C>
For the melt color difference of bisphenol C, put 20 g of bisphenol C in a test tube P-24 (24 mmφ x 200 mm) manufactured by Nichiden Rika Glass Co., Ltd., melt it at 190 ° C. for 30 minutes, and use SE6000 manufactured by Nippon Denshoku Kogyo Co., Ltd. to obtain the Hazen color. The number was measured. The number of Hazen colors is preferably 50 or less.

<Viscosity average molecular weight (Mv)>
The viscosity average molecular weight (Mv) of the polycarbonate resin is determined by dissolving the polycarbonate resin in methylene chloride (concentration 6.0 g / L), measuring the specific viscosity (ηsp) at 20 ° C. using a Uberode viscosity tube, and using the following formula. The viscosity average molecular weight (Mv) was calculated.
ηsp / C = [η] (1 + 0.28ηsp)
[Η] = 1.23 × 10 ^-4 Mv ^0.8

<Pellet YI>
The pellet YI (transparency of the polycarbonate resin) was evaluated by measuring the YI value (yellowness index value) in the reflected light of the polycarbonate resin pellet in accordance with ASTM D1925. A spectrocolorimeter CM-5 manufactured by Konica Minolta Co., Ltd. was used as an apparatus, and a measurement diameter of 30 mm and SCE were selected as measurement conditions.
The calibration glass CM-A212 for petri dish measurement was fitted into the measuring section, and the zero calibration box CM-A124 was placed over the measurement unit to perform zero calibration, and then white calibration was performed using the built-in white calibration plate. Next, measurement was performed using the white calibration plate CM-A210, where L * was 99.40 ± 0.05, a * was 0.03 ± 0.01, b * was -0.43 ± 0.01, and YI. Was confirmed to be −0.58 ± 0.01.
YI measured the pellets in a cylindrical glass container having an inner diameter of 30 mm and a height of 50 mm, packed to a depth of about 40 mm. The operation of taking out the pellets from the glass container and then performing the measurement again was repeated twice, and the average value of the measured values of a total of three times was used. The pellet YI is preferably 20 or less.

[Example 1]
(1) Preparation of the 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 230 g (2.13 mol) of orthocresol were placed in a nitrogen atmosphere. The temperature was set to 10 ° C. or lower. Then, 95 g of 98 mass% sulfuric acid was slowly added over 0.3 hours with stirring, and then cooled to 5 ° C. or lower.

(2) Preparation of Second Mixture Solution 50 g of toluene, 65 g of acetone (1.12 mol), and 5.4 g of dodecanethiol were mixed in a 500 mL Erlenmeyer flask to prepare a second mixed solution (drop solution).

(3) Preparation of reaction solution After the internal temperature of the first mixed solution is set to 5 ° C. or lower, the second mixed solution is prepared using the dropping funnel for 1 hour so that the internal temperature does not exceed 10 ° C. The reaction solution was prepared.

(4) Reaction The prepared reaction solution was stirred at an internal temperature of 10 ° C. for 2.5 hours.

(5) After completion of the crude purification reaction, 190 g of a 25 mass% sodium hydroxide aqueous solution was supplied and the temperature was raised to 80 ° C. After reaching 80 ° C., the mixture was allowed to stand and the aqueous phase of the lower layer was extracted. 400 g of desalinated water was added to the obtained first organic phase, mixed for 30 minutes and allowed to stand to remove the aqueous phase. 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained second organic phase, mixed for 30 minutes and allowed to stand, and the lower layer was extracted. Further, 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained third organic phase, mixed for 30 minutes and allowed to stand, and the lower layer was extracted. The obtained fourth organic phase was extracted and its mass was measured and found to be 666 g.

When a part of the fourth organic phase was taken out and the composition of the fourth organic phase was confirmed by high-speed liquid chromatography, the content of orthocresol was 5.8% by mass (5.8% by mass x the mass of the organic phase 666 g ÷ ortho). Molecular weight of cresol 108 g / mol ÷ Substance amount of ortho-cresol charged 2.1 mol = 16.8 mol%), bisphenol C 31.4% by mass (31.4% by mass × mass of organic phase 666 g × 2 ÷ bisphenol The molecular weight of C was 256 g / mol ÷ the substance amount of the charged orthocresol was 2.1 mol = 76.7 mol%).

(6) Purification The obtained 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 wet cake.

The total amount of 211 g of the crude bisphenol C and 373 g of toluene were placed in a full-jacket type 1 liter separable flask equipped with a thermometer and a stirrer, and the temperature was raised to 80 ° C. After confirming that the solution was uniform, a fifth organic phase (organic phase (O1)) was obtained. 200 g of demineralized water was added to the obtained fifth organic phase (O1), mixed for 30 minutes and allowed to stand, and the lower aqueous phase (first aqueous phase (W1)) was removed. The pH of the first aqueous phase (W1) was 9.7. 200 g of demineralized water was added to the sixth organic phase (organic phase (O2)) obtained by removing the first aqueous phase (W1), mixed for 30 minutes, and then allowed to stand, and the lower aqueous phase (first) was allowed to stand. 2) was removed. 200 g of desalinated water was added to the seventh organic phase obtained by removing the lower layer, mixed for 30 minutes, and then allowed to stand to remove the lower aqueous phase (third aqueous phase (W2)). The electrical conductivity of the third aqueous phase (W2) was 1.7 μS / cm.

The eighth organic phase (O3) obtained by removing the third aqueous phase (W2) was cooled from 80 ° C. to 10 ° C. to precipitate bisphenol C. Then, filtration was performed using a centrifuge (3000 rpm for 10 minutes) to obtain wet purified bisphenol C. Using an evaporator equipped with an oil bath, a light boiling point was distilled off at an oil bath temperature of 100 ° C. under reduced pressure to obtain 193 g of white bisphenol C.

The melt color difference of the obtained bisphenol C: Hazen color number APHA was 21.

(6) Polymerization In a glass reaction tank with an internal volume of 150 mL equipped with a stirrer and a distillate, 100.00 g (0.39 mol) of bisphenol C, 86.49 g (0.4 mol) of diphenyl carbonate and 400 mass ppm. 479 μL of the cesium carbonate aqueous solution of the above was added. The operation of reducing the pressure of the glass reaction vessel to about 100 Pa and then restoring the pressure to atmospheric pressure with nitrogen was repeated three times to replace the inside of the reaction vessel with nitrogen. Then, the reaction vessel was immersed in an oil bath at 200 ° C. to melt the contents.

The rotation speed of the stirrer is set to 100 times per minute, and the pressure in the reaction vessel is increased by absolute pressure over 40 minutes while distilling off the phenol produced by 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 transesterification reaction was carried out for 80 minutes while maintaining the pressure in the reaction vessel at 13.3 kPa and further distilling off phenol. Then, the temperature outside the reaction vessel was raised to 250 ° C., and the pressure inside the reaction vessel was reduced from 13.3 kPa to 399 Pa in absolute pressure over 40 minutes to remove the distilled phenol from the system.

Then, the temperature outside the reaction vessel was raised to 280 ° C., the absolute pressure of the reaction vessel was reduced to 30 Pa, and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the stirrer in the reaction tank became a predetermined stirring power. The time from the temperature rise to 280 ° C. to the end of the polymerization (post-stage polymerization time) was 170 minutes.

Next, the reaction vessel was repressurized to 101.3 kPa with nitrogen at an absolute pressure, and then the pressure was increased to 0.2 MPa with a gauge pressure, and the polycarbonate resin was extracted from the bottom of the reaction vessel in a strand shape to obtain a strand-shaped polycarbonate resin. ..
Then, the strands were pelletized using a rotary cutter to obtain a pellet-shaped polycarbonate resin.
The viscosity average molecular weight (Mv) of the polycarbonate was 24,800 and the pellet YI was 7.4.

[Comparative Example 1]
In Example 1, the same procedure as in Examples 1 (1) to (4) was carried out except that the supply of 5.4 g of dodecane thiol was omitted.

(5) Crude Purification After the reaction yield, 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 and the aqueous phase of the lower layer was extracted. 400 g of desalinated water was added to the obtained first organic phase, mixed for 30 minutes and allowed to stand to remove the aqueous phase. 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained second organic phase, mixed for 30 minutes and allowed to stand, and the lower layer was extracted. Further, 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained third organic phase, mixed for 30 minutes and allowed to stand, and the lower layer was extracted. The obtained fourth organic phase was extracted and its mass was measured and found to be 659 g.

When a part of the fourth organic phase was taken out and the composition of the fourth organic phase was confirmed by high-speed liquid chromatography, the orthocresol was 10.2% by mass (10.2% by mass × the mass of the organic phase 659 g ÷ ortho). Molecular weight of cresol 108 g / mol ÷ Substance amount of ortho-cresol charged 2.1 mol = 29.6 mol%), bisphenol C 21.3% by mass (21.3% by mass × mass of organic phase 659 g × 2 ÷ bisphenol The molecular weight of C was 256 g / mol ÷ the substance amount of the charged orthocresol was 2.1 mol = 52.2 mol%).

(6) Purification The obtained 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 wet cake.

The total amount of 152 g of the crude bisphenol C and 373 g of toluene were placed in a full-jacket type 1 liter separable flask equipped with a thermometer and a stirrer, and the temperature was raised to 80 ° C. After confirming that the solution was uniform, a fifth organic phase (organic phase (O1)) was obtained. 200 g of demineralized water was added to the obtained fifth organic phase (O1), mixed for 30 minutes and allowed to stand, and the lower aqueous phase (first aqueous phase (W1)) was removed. The pH of the first aqueous phase (W1) was 9.7. 200 g of demineralized water was added to the sixth organic phase (organic phase (O2)) obtained by removing the first aqueous phase (W1), mixed for 30 minutes and allowed to stand, and the lower aqueous phase (second) was allowed to stand. Water phase) was removed. 200 g of desalinated water was added to the seventh organic phase obtained by removing the lower layer, mixed for 30 minutes and allowed to stand, and the lower aqueous phase (third aqueous phase (W2)) was removed. The electrical conductivity of the third aqueous phase (W2) was 3.7 μS / cm.

The eighth organic phase (O3) obtained by removing the third aqueous phase (W2) was cooled from 80 ° C to 10 ° C. Then, filtration was performed using a centrifuge (3000 rpm for 10 minutes) to obtain wet purified bisphenol C. Using an evaporator equipped with an oil bath, a light boiling point was distilled off at an oil bath temperature of 100 ° C. under reduced pressure to obtain 127 g of white bisphenol C.

The melt color difference of the obtained bisphenol C: Hazen color number APHA was 134.

(6) Polymerization In a glass reaction tank with an internal volume of 150 mL equipped with a stirrer and a distillate, 100.00 g (0.39 mol) of bisphenol C, 86.49 g (0.4 mol) of diphenyl carbonate and 400 mass ppm. 479 μL of the cesium carbonate aqueous solution of the above was added. The operation of reducing the pressure of the glass reaction vessel to about 100 Pa and then restoring the pressure to atmospheric pressure with nitrogen was repeated three times to replace the inside of the reaction vessel with nitrogen. Then, the reaction vessel was immersed in an oil bath at 200 ° C. to melt the contents.

The rotation speed of the stirrer is set to 100 times per minute, and the pressure in the reaction vessel is increased by absolute pressure over 40 minutes while distilling off the phenol produced by 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 transesterification reaction was carried out for 80 minutes while maintaining the pressure in the reaction vessel at 13.3 kPa and further distilling off phenol. Then, the temperature outside the reaction vessel was raised to 250 ° C., and the pressure inside the reaction vessel was reduced from 13.3 kPa to 399 Pa in absolute pressure over 40 minutes to remove the distilled phenol from the system.

Then, the temperature outside the reaction vessel was raised to 280 ° C., the absolute pressure of the reaction vessel was reduced to 30 Pa, and the polycondensation reaction was carried out. When the stirrer in the reaction tank became a predetermined stirring power, the polycondensation reaction was attempted to be terminated, but the time from the temperature rise to 280 ° C. to the completion of the polymerization (post-stage polymerization time) was I gave up because the stirring power did not reach the specified level even after 240 minutes. Next, the reaction vessel was repressurized to 101.3 kPa with nitrogen at an absolute pressure, and then the pressure was increased to 0.2 MPa with a gauge pressure, and polycarbonate was extracted from the bottom of the reaction vessel in a strand shape to obtain a strand-shaped polycarbonate resin. The obtained polycarbonate resin had an amber color.

Regarding Example 1 and Comparative Example 1, the presence or absence of thiol in the reaction for producing bisphenol, the electrical conductivity of the third aqueous phase (W2), the amount of bisphenol C obtained, the reachability of a predetermined stirring power, and so on. The melt color difference of the obtained bisphenol C and the color tone of the method for producing the polycarbonate resin are summarized in Table 1 below.

From this result, when thiol was not added to the condensation reaction for producing bisphenol, the amount of bisphenol C obtained was small, the color tone (melted color difference) deteriorated, and the electrical conductivity of the third aqueous phase (W2) was improved. It can be seen that even if the temperature is lowered to 10 μS / cm or less, the predetermined stirring power cannot be reached due to the polymerization reaction of the polycarbonate resin (polymerization activity is low), and the color tone of the obtained polycarbonate resin also deteriorates.
On the other hand, when thiol is used, the amount of bisphenol C obtained is large, the color tone (melted color difference) is also improved, and the electric conductivity of the third aqueous phase (W2) is lowered to 10 μS / cm or less. It can be seen that the stirring power can reach a predetermined torque, and a polycarbonate resin having a target molecular weight and a good color tone can be obtained.
From these results, by supplying thiol to the condensation reaction system for producing bisphenol, in the condensation reaction for producing bisphenol, the formation of an inhibitor to the polymerization reaction for producing a polycarbonate resin is suppressed, and the formation of a color-deteriorating product is produced. It is presumed that it can be suppressed.

[Example 2]
In Example 1, 200 g of demineralized water supplied to the organic phases 5 to 7 was changed to 100 g, respectively, but the same procedure as in Example 1 was carried out.
As a result, the pH of the first aqueous phase (W1) was 10.1. The electrical conductivity of the third aqueous phase (W2) was 6.2 μS / cm.
Further, the melt color difference of the obtained bisphenol C: Hazen color number APHA was 25.
The viscosity average molecular weight (Mv) of the obtained polycarbonate resin was 24700, and the pellet YI was 10.6.

[Comparative Example 2]
In Example 1, the same procedure as in Example 1 was carried out except that (5) two washings of 120 g of 1.5% by mass sodium hydrogen carbonate solution in crude purification were omitted.
As a result, the pH of the first aqueous phase (W1) was 3.4. The electrical conductivity of the third aqueous phase (W2) was 5.2 μS / cm.
Further, the melt color difference of the obtained bisphenol C: Hazen color number APHA was 65.
The viscosity average molecular weight (Mv) of the obtained polycarbonate was 23,700, and the pellet YI was 33.2.

For Examples 1 and 2 and Comparative Example 2, the pH of the first aqueous phase (W1), the electric conductivity of the third aqueous phase (W2), the melt color difference of the obtained bisphenol C, and the obtained polycarbonate resin. The viscosity average molecular weight (Mv) and pellet YI are summarized in Table 2 below.

From Table 2, when the pH of the first aqueous phase (W1) is 8.5 or more (basic) and the electrical conductivity of the third aqueous phase (W2) is 10 μS / cm or less, the bisphenol C is melted. It can be seen that the color difference is good, the viscosity average molecular weight (Mv) of the polycarbonate resin obtained in the same polymerization time is high, the polymerization time is short (polymerization activity is good), and the pellet YI is also low.
In Comparative Example 2, even if thiol is used, it is presumed that the pH of the first aqueous phase (W1) is low (acidic), so that the thiol becomes thionium (acidic substance) and the polymerization is inhibited.

[Comparative Example 3]
In Example 1, 200 g of demineralized water was added to the obtained seventh organic phase, mixed for 30 minutes and allowed to stand, and the operation of removing the lower aqueous phase (third aqueous phase) was omitted. It was carried out in the same manner as in Example 1 except that it was cooled from 80 ° C. to 10 ° C. using the organic phase of. As a result, the pH of the first aqueous phase (W1) was 9.5. The electrical conductivity of the second aqueous phase (W2) was 22.1 μS / cm. Further, the melt color difference of the obtained bisphenol C: Hazen color number APHA was 30.
Further, the obtained bisphenol C was used to carry out a polymerization reaction in the same manner as in Example 1, but the polymerization did not proceed and a polycarbonate resin could not be obtained.
From this result, even if the pH of the first aqueous phase (W1) is as basic as 9.5, when the electric conductivity of the second aqueous phase (W2) is 22.1 μS / cm, it can be used as a raw material for producing a polycarbonate resin. It can be seen that the polymerization activity cannot be obtained.

[Example 3]
(1) Preparation of mixed solution In a separable flask equipped with a hydrogen chloride blowing tube, a thermometer, a jacket and an anchor-type stirring blade, 620 g (5.7 mol) of orthocresol and 55 g (0.9 mol) of acetone under a nitrogen atmosphere. ) And 25 g of ethyl mercaptan were added, and the internal temperature was set to 30 ° C. to prepare a mixed solution.

(2) Reaction The mixed solution was bubbled with hydrogen chloride gas and reacted for 12 hours to obtain a reaction solution.

(3) Distillation of unreacted orthocresol The reaction solution was transferred to a 2 L flask and heated under reduced pressure to distill off unreacted orthocresol from the reaction solution to obtain a residue.

(4) Crude Purification 400 g of toluene was added to the obtained residue, and the mixture was transferred to a separable flask equipped with a thermometer, a jacket and an anchor-type stirring blade. The internal temperature was raised to 80 ° C., 400 g of desalinated water was added to the obtained first organic phase, mixed for 30 minutes and allowed 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, mixed for 30 minutes and allowed to stand, and the lower layer was extracted. Further, 120 g of a 1.5% by mass sodium hydrogen carbonate solution was added to the obtained third organic phase, mixed for 30 minutes and allowed to stand, and the lower layer was extracted.

(6) Purification The obtained 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 wet cake.

The total amount of 156 g of the crude bisphenol C and 373 g of toluene were placed in a full-jacket type 1 liter separable flask equipped with a thermometer and a stirrer, and the temperature was raised to 80 ° C. After confirming that the solution was uniform, a fifth organic phase (organic phase (O1)) was obtained. 200 g of demineralized water was added to the obtained fifth organic phase (O1), mixed for 30 minutes and allowed to stand, and the lower aqueous phase (first aqueous phase (W1)) was removed. The pH of the first aqueous phase (W1) was 9.1. 200 g of desalted water was added to the sixth organic phase (O2) obtained by removing the first aqueous phase (W1), mixed for 30 minutes and allowed to stand, and the lower aqueous phase (second aqueous phase) was allowed to stand. Was removed. To the obtained seventh organic phase (organic phase (O3)), 200 g of desalinated water was added, mixed for 30 minutes and allowed to stand, and the lower aqueous phase (third aqueous phase (W2)) was removed. The electrical conductivity of the third aqueous phase (W2) was 0.8 μS / cm.

The eighth organic phase (O3) obtained by removing the third aqueous phase (W2) was cooled from 80 ° C to 10 ° C. Then, filtration was performed using a centrifuge (3000 rpm for 10 minutes) to obtain wet purified bisphenol C. Using an evaporator equipped with an oil bath, a light boiling point was distilled off at an oil bath temperature of 100 ° C. under reduced pressure to obtain 126 g of white bisphenol C.

(6) Polymerization In a glass reaction tank with an internal volume of 150 mL equipped with a stirrer and a distillate, 100.00 g (0.39 mol) of bisphenol C, 86.49 g (0.4 mol) of diphenyl carbonate and 400 mass ppm. 479 μL of the cesium carbonate aqueous solution of the above was added. The operation of reducing the pressure of the glass reaction vessel to about 100 Pa and then restoring the pressure to atmospheric pressure with nitrogen was repeated three times to replace the inside of the reaction vessel with nitrogen. Then, the reaction vessel was immersed in an oil bath at 200 ° C. to melt the contents.

The rotation speed of the stirrer is set to 100 times per minute, and the pressure in the reaction vessel is increased by absolute pressure over 40 minutes while distilling off the phenol produced by 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 transesterification reaction was carried out for 80 minutes while maintaining the pressure in the reaction vessel at 13.3 kPa and further distilling off phenol. Then, the temperature outside the reaction vessel was raised to 250 ° C., and the pressure inside the reaction vessel was reduced from 13.3 kPa to 399 Pa in absolute pressure over 40 minutes to remove the distilled phenol from the system.

Then, the temperature outside the reaction vessel was raised to 280 ° C., the absolute pressure of the reaction vessel was reduced to 30 Pa, and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the stirrer in the reaction tank became a predetermined stirring power. The time from the temperature rise to 280 ° C. to the end of the polymerization (post-stage polymerization time) was 165 minutes.

Next, the reaction vessel was repressurized to 101.3 kPa with nitrogen at an absolute pressure, and then the pressure was increased to 0.2 MPa with a gauge pressure, and the polycarbonate resin was extracted from the bottom of the reaction vessel in a strand shape to obtain a strand-shaped polycarbonate resin. ..
Then, the strands were pelletized using a rotary cutter to obtain a pellet-shaped polycarbonate resin.
The viscosity average molecular weight (Mv) of the polycarbonate was 25,800 and the pellet YI was 6.3.

[Comparative Example 4]
In Example 3, the same procedure as in Example 3 was carried out except that (5) two rough purifications of 120 g of a 1.5% by mass sodium hydrogen carbonate solution were omitted.
As a result, the pH of the first aqueous phase (W1) was 4.5. The electrical conductivity of the third aqueous phase (W2) was 15.7 μS / cm.
Further, the obtained bisphenol C was used to carry out a polymerization reaction in the same manner as in Example 3, but the polymerization did not proceed and a polycarbonate resin could not be obtained.

For Examples 1, 3 and Comparative Example 4, the catalyst for producing bisphenol C, the pH of the first aqueous phase (W1), the electrical conductivity of the third aqueous phase (W2), and the viscosity average of the obtained polycarbonate resin. The molecular weight (Mv) and pellet YI are summarized in Table 3 below.

From Table 3, even when hydrogen chloride is used as a catalyst for the condensation reaction for producing bisphenol, the pH of the first aqueous phase (W1) is 8.5 or more (basic), and the third aqueous phase (W2). It can be seen that when the electrical conductivity of) is 10 μS / cm or less, the polymerization time for producing the polycarbonate resin is short (the polymerization activity is good), and the pellet YI is also small.

Claims (4)

Bisphenol having a reaction step of condensing a ketone or aldehyde with an aromatic alcohol in the presence of an acid catalyst and thiol to obtain bisphenol, a washing step of washing the obtained bisphenol, and a crystallization step of precipitating bisphenol. In the manufacturing method of
In the washing step, after mixing the organic phase (O1) containing bisphenol and desalinated water, the organic phase (O2) containing bisphenol and the aqueous phase (W1) are phase-separated, and the aqueous phase (W1) is separated. In the first step of removing the above to obtain the organic phase (O2) containing the bisphenol,
After mixing the bisphenol-containing organic phase (O2) obtained in the first step with desalinated water, the phase is separated into the bisphenol-containing organic phase (O3) and the aqueous phase (W2), and the aqueous phase is separated. It has a second step of washing with water to remove (W2) and obtain the organic phase (O3) containing the bisphenol.
The pH of the aqueous phase (W1) is 8.5 or higher, and the pH is 8.5 or higher.
The second step is a step of repeating the washing with water as necessary so that the electric conductivity of the aqueous phase (W2) is 10 μS / cm or less.
A method for producing bisphenol, which comprises subjecting the organic phase (O3) that has undergone the washing step to the crystallization step. The method for producing bisphenol according to claim 1, wherein the acid catalyst is sulfuric acid or hydrogen chloride. The method for producing bisphenol according to claim 1 or 2, wherein the bisphenol is 2,2-bis (4-hydroxy-3-methylphenyl) propane. A method for producing a polycarbonate resin using the bisphenol produced by the method for producing bisphenol according to any one of claims 1 to 3.