WO2015159958A1

WO2015159958A1 - Method for producing polycarbonate resin

Info

Publication number: WO2015159958A1
Application number: PCT/JP2015/061746
Authority: WO
Inventors: 幸子長尾; 菅　浩一; 亜起山田
Original assignee: 出光興産株式会社
Priority date: 2014-04-17
Filing date: 2015-04-16
Publication date: 2015-10-22
Also published as: TW201542619A

Abstract

A method for producing a polycarbonate resin by reacting a polycarbonate oligomer having a weight average molecular weight of less than 5000 with an aqueous alkali solution containing a bivalent phenol, said method being characterized by comprising: introducing the polycarbonate oligomer, 3-pentadecylphenol produced from a natural material and having a purity of 97.5% by mass or more and a caustic alkali to an inlet port for a first reaction zone to cause the reaction of the polycarbonate oligomer with 3-pentadecylphenol in the first reaction zone, thereby producing a reaction solution containing a polycarbonate oligomer in which some of terminal groups are 3-pentadecylphenoxy groups; and then introducing the reaction solution produced in the first reaction zone, an aqueous alkali solution containing a bivalent phenol and a caustic alkali to an inlet port for a second reaction zone, wherein the whole volume of the caustic alkali to be introduced to the second reaction zone is introduced through the inlet port for the second reaction zone, and the reaction of these components is performed in the second reaction zone.

Description

Method for producing polycarbonate resin

The present invention relates to a method for producing a polycarbonate resin. Specifically, the present invention relates to a method for producing a polycarbonate resin having a pentadecylphenoxy group at a terminal group by an interfacial polymerization method.

Polycarbonate resins have excellent characteristics such as transparency, heat resistance, and mechanical properties, and are used in a wide range of applications such as OA / home appliance casings, members in the electrical / electronic field, and optical materials such as lenses. In recent years, it has become necessary to further improve fluidity in response to demands for thinner and larger molded products and improved molding cycles.
As a method of improving the fluidity of a molding material using a polycarbonate resin, a method of using a plasticizer or a resin having excellent fluidity such as a styrene resin such as ABS, HIPS, AS is used. ing. However, although these methods can improve the fluidity of the polycarbonate resin, there is a problem that the excellent impact resistance inherent in the polycarbonate resin is lowered.

As a method for producing a polycarbonate resin, a polymerization method using an interfacial polymerization method or a transesterification method is known. In these polymerization methods, a terminal terminator (molecular weight regulator) is used to regulate the molecular weight of the resulting polycarbonate resin.
In order to avoid the above problems, it is known to improve the fluidity by changing the structure of the polycarbonate resin itself by using a long-chain alkylphenol as a terminal stopper as a terminal stopper.

As a method for producing a polycarbonate resin using the above long-chain alkylphenol as a terminal stopper, Patent Document 1 and Patent Document 2 describe a production method by an interfacial polymerization method using 3-pentadecylphenol. However, the production methods described in Patent Documents 1 and 2 only describe a laboratory batch production method in which a raw material is charged into a flask and reacted while adding phosgene to the raw material liquid.

JP 2005-524923 A JP 2003-41011 A

When continuously producing a polycarbonate resin by the interfacial polymerization method using the above-mentioned 3-pentadecylphenol as a terminal terminator, if 3-pentadecylphenol is used in the polycondensation step, the reaction temperature becomes high. The resulting polycarbonate resin has a high terminal hydroxyl group fraction, which may adversely affect the YI value of the molded product.
In addition, it is necessary to use caustic alkali in order to accelerate the polycondensation reaction in the polycondensation step. However, when caustic alkali is dividedly added in the polycondensation step or added in the middle of the polycondensation step, the polycondensation step When the reaction solution (emulsion solution) obtained from the above is separated into an aqueous phase and an organic phase containing a polycarbonate resin, there is a problem in that the separation performance deteriorates and the production efficiency is not good.

The object of the present invention is to devise the addition position of 3-pentadecylphenol and caustic alkali in the reaction step when producing a polycarbonate resin by interfacial polymerization using 3-pentadecylphenol as a terminal stopper. It is an object of the present invention to provide a method for producing a polycarbonate resin, in which the obtained polycarbonate resin molded article has a good YI value and is excellent in productivity.

As a result of diligent study, the present inventors have found that the position of addition of 3-pentadecylphenol and caustic alkali in the continuous production of polycarbonate resin by interfacial polymerization using 3-pentadecylphenol as a terminal terminator. When the position is set to an appropriate position, the YI value of the obtained polycarbonate resin molded article is improved, and a method for producing a polycarbonate resin excellent in productivity has been found and the present invention has been completed.
That is, the present invention relates to the following [1] to [13].

[1] In a method for producing a polycarbonate resin by reacting a polycarbonate oligomer having a weight average molecular weight of less than 5000 and an alkaline aqueous solution of dihydric phenol, the polycarbonate oligomer is obtained from the natural product at the inlet to the first reaction zone. A 3-pentadecylphenol having a purity of 97.5% by mass or more and caustic are introduced, and the polycarbonate oligomer and 3-pentadecylphenol are reacted in the first reaction zone. -A reaction liquid containing a polycarbonate oligomer which is a pentadecylphenoxy group is generated, and then the reaction liquid obtained from the first reaction zone, an aqueous alkali solution of dihydric phenol and caustic alkali are introduced into the inlet to the second reaction zone. And caustic to be introduced into the second reaction zone. Alkaline method for manufacturing a polycarbonate resin, characterized in that the reaction is carried out by introducing the total amount from the inlet of the second reaction zone in a second reaction zone.
[2] The polycarbonate according to [1], wherein the reaction is carried out by introducing at least one selected from pt-butylphenol, p-cumylphenol and phenol as a terminal stopper in the second reaction zone. Manufacturing method of resin.
[3] The above [2], wherein the molar ratio of 3-pentadecylphenol introduced into the first reaction zone and the terminal terminator introduced into the second reaction zone is 1: 9 to 9: 1. Of producing a polycarbonate resin.
[4] The method for producing a polycarbonate resin according to the above [1], wherein the reaction is performed in the second reaction zone without introducing a terminal terminator into the second reaction zone.
[5] The method for producing a polycarbonate resin according to any one of [1] to [4] above, wherein 3-pentadecylphenol is introduced into the first reaction zone as a solution dissolved in methylene chloride.
[6] The method for producing a polycarbonate resin according to any one of the above [1] to [5], wherein the temperature of the second reaction zone is 20 to 36 ° C.
[7] The polycarbonate resin according to any one of [1] to [6] above, wherein 5 to 50 mol% of all terminal groups of the polycarbonate oligomer obtained from the first reaction zone are 3-pentadecylphenoxy groups Manufacturing method.
[8] The production of the polycarbonate resin according to any one of [1] to [7] above, wherein 50 to 95 mol% of all terminal groups of the polycarbonate oligomer obtained from the first reaction zone are chloroformate groups. Method.
[9] The method for producing a polycarbonate resin according to any one of [1] to [8] above, wherein the obtained polycarbonate resin has a viscosity average molecular weight of 8,000 to 20,000.
[10] The method for producing a polycarbonate resin according to any one of the above [1] to [9], wherein the polycarbonate oligomer having a weight average molecular weight of less than 5000 is obtained using bisphenol A.
[11] The method for producing a polycarbonate resin according to any one of the above [1] to [10], wherein the dihydric phenol is bisphenol A.
[12] The method for producing a polycarbonate resin according to any one of the above [1] to [11], wherein pentadecylphenol introduced into the first reaction zone is reacted at 95% or more in the first reaction zone.
[13] The method for producing a polycarbonate resin according to any one of the above [1] to [12], wherein a line mixer is used in the first reaction zone and / or the second reaction zone.

According to the present invention, the YI value of the obtained polycarbonate resin molded product becomes good, the color tone can be improved, and the production efficiency of the polycarbonate resin can be increased.

1 is a schematic diagram showing a reaction process used in Example 1. FIG. Schematic which shows the reaction process used in the comparative example 2. FIG. Schematic which shows the reaction process used in the comparative example 3. FIG.

The method for producing a polycarbonate resin of the present invention is a method for producing a polycarbonate resin by reacting a polycarbonate oligomer having a weight average molecular weight of less than 5,000 with an alkaline aqueous solution of a dihydric phenol. Introducing 3-pentadecylphenol having a purity of 97.5% by mass or more obtained from an oligomer or a natural product and caustic, and reacting the polycarbonate oligomer with 3-pentadecylphenol in the first reaction zone, A reaction liquid containing a polycarbonate oligomer in which a part of the end groups is a 3-pentadecylphenoxy group is generated, and then the reaction liquid obtained from the first reaction zone, an aqueous alkali solution of dihydric phenol and caustic alkali are added to the second reaction zone. To the introduction to In which the reaction is carried out in the second reaction zone.
Hereafter, the manufacturing method of the polycarbonate resin of this invention is demonstrated in detail. In the present specification, it is possible to arbitrarily adopt provisions that are preferable, and it can be said that a combination of preferable ones is more preferable.

[Polycarbonate oligomer having a weight average molecular weight of less than 5000]
Although there is no restriction | limiting in particular about the manufacturing method of the polycarbonate oligomer whose weight average molecular weight used for the manufacturing method of the polycarbonate resin of this invention is less than 5000, For example, the method shown next can be used preferably.
First, prepare an alkaline aqueous solution of dihydric phenol, mix this alkaline aqueous solution of dihydric phenol with an organic solvent such as methylene chloride, and stir phosgene in the presence of the alkaline aqueous solution of dihydric phenol and organic solvent while stirring. By reacting, a polycarbonate oligomer is obtained.

As the dihydric phenol, it is preferable to use a dihydric phenol represented by the following general formula (1).

In the general formula (1), R ¹ and R ² each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, a fluorenediyl group, a carbon An arylalkylene group having 7 to 15 carbon atoms, an arylalkylidene group having 7 to 15 carbon atoms, —S—, —SO—, —SO ₂ —, —O— or —CO—; a and b each independently represent an integer of 0 to 4.

The dihydric phenol represented by the general formula (1) is not particularly limited, but 2,2-bis (4-hydroxyphenyl) propane [common name: bisphenol A] is preferable.
Examples of dihydric phenols other than bisphenol A include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2 -Bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4- Hydroxyphenyl) naphthylmethane, 1,1-bis (4-hydroxy-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-) 3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl) Bis (hydroxyaryl) alkanes such as propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 1, 1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,5,5-trimethylcyclohexane, 2,2- Bis (hydroxyaryl) cycloalkanes such as bis (4-hydroxyphenyl) norbornane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3, Dihydroxy aryl ethers such as 3′-dimethylphenyl ether, 4,4′-dihy Roxydiphenyl sulfide, dihydroxydiaryl sulfides such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide Dihydroxydiaryl sulfoxides such as 4,4′-dihydroxydiphenylsulfone, dihydroxydiarylsulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone, and dihydroxydiphenyls such as 4,4′-dihydroxydiphenyl Dihydroxydiarylfluorenes such as 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 1,3-bis (4-hydroxyphenyl) ada Dihydroxydiaryladamantanes such as tantalum, 2,2-bis (4-hydroxyphenyl) adamantane, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4 ′-[1,3- Phenylenebis (1-methylethylidene)] bisphenol, 10,10-bis (4-hydroxyphenyl) -9-anthrone, 1,5-bis (4-hydroxyphenylthio) -2,3-dioxapentane, etc. It is done.
These dihydric phenols may be used alone or in admixture of two or more.

Furthermore, the dihydric phenol not contained in the dihydric phenol represented by the general formula (1) is represented by the general formula (1), and the dihydric phenol containing the structural unit represented by the following formula (2) is represented by the general formula (1). Can be used in combination with the dihydric phenol. By setting it as the copolymer which has such a structural unit, the flame retardance of polycarbonate resin can be improved. Examples of the dihydric phenol containing a structural unit represented by the following general formula (2) include a polyorganosiloxane compound represented by the following general formula (2-1).

In the general formula (2) or the general formula (2-1), R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom. An alkoxy group having 6 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms; Z represents a phenol residue having a trimethylene group, which is derived from a phenol compound having an allyl group. n represents 30 to 1000.
The polyorganosiloxane represented by the general formula (2-1) is obtained by modifying the terminal of a polyorganosiloxane having a hydrogen end with a phenol compound having an allyl group such as 2-allylphenol and eugenol. . The polyorganosiloxane modified with a phenol compound having an allyl group at the end can be synthesized by the method described in Japanese Patent No. 2662310.
As the polyorganosiloxane, dimethylsiloxane is preferred.

Furthermore, with respect to the dihydric phenol represented by the general formula (1) and the dihydric phenol containing the structural unit represented by the formula (2), a branching agent is used in the main chain of the polycarbonate resin. It can also have a branched structure. The amount of the branching agent added is preferably 0.01 to 3 mol%, more preferably 0.1 to 1.0 mol%, based on the dihydric phenol.
Examples of the branching agent include 1,1,1-tris (4-hydroxyphenyl) ethane, 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl ] Ethylidene] bisphenol, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl]- Examples include compounds having three or more functional groups such as 4- [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, phloroglucin, trimetic acid, and isatin bis (o-cresol).

Further, as the alkaline aqueous solution, an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide can be preferably used, and usually one having a concentration of 1 to 15% by mass is preferably used. The content of the dihydric phenol in the alkaline aqueous solution is usually selected in the range of 0.5 to 20% by mass. Further, the amount of the organic solvent used is desirably selected so that the volume ratio of the organic phase to the aqueous phase is 5/1 to 1/7, preferably 2/1 to 1/4. The reaction temperature is usually selected in the range of 0 to 70 ° C, preferably 5 to 40 ° C. The chloroformate end group concentration in the obtained polycarbonate oligomer is usually 0.6 to 0.9 mol / L, and a polycarbonate oligomer having a weight average molecular weight of less than 5,000 can be obtained.
In the polycarbonate oligomer production process, a monohydric phenol other than 3-pentadecylphenol, for example, a compound such as pt-butylphenol, p-cumylphenol, or phenol, is used as a terminal terminator (molecular weight regulator) as necessary. It may be used, and some of the chloroformate end groups may be terminated with these compounds. Further, as a terminal stopper, a part of 3-pentadecylphenol used in the first reaction zone may be divided and used.
As a reactor, it can manufacture by a continuous type or a batch type using a tank reactor. Moreover, it is also a preferable manufacturing method to manufacture continuously using a tubular reactor.
The reaction solution obtained by the method described above is obtained as an emulsion state of an organic phase containing a polycarbonate oligomer having a weight average molecular weight of less than 5000 and an aqueous phase containing impurities such as sodium chloride. The organic phase containing the polycarbonate oligomer is separated into the organic phase containing the polycarbonate oligomer and the aqueous phase by standing separation or the like, and the separated organic phase containing the polycarbonate oligomer is used in the first reaction zone. The lower limit of the weight average molecular weight of a polycarbonate oligomer having a weight average molecular weight of less than 5000 is usually about 500.

[First reaction zone]
The first reaction zone defined in the present invention refers to a part of the polycarbonate oligomer end group having a weight average molecular weight of less than 5000, and 3-pentadecylphenol having a purity of 97.5% by mass or more obtained from a natural product. The objective is to produce a polycarbonate oligomer having a 3-pentadecylphenoxy group, and no polycondensation reaction is carried out in this first reaction zone.

<Raw materials used in the first reaction zone>
(I) Polycarbonate oligomer having a weight average molecular weight of less than 5000 As described above, a polycarbonate oligomer having a weight average molecular weight of less than 5000 is used as an organic phase containing a polycarbonate oligomer having a weight average molecular weight of less than 5000. As the organic solvent for the organic phase, methylene chloride is preferably used.
(Ii) 3-pentadecylphenol having a purity of 97.5% by mass or more obtained from natural products 3-pentadecylphenol (hereinafter sometimes referred to as PDP) is generally derived from natural products such as cashew nut shell oil. It is obtained by subjecting a composition containing cardanol as a main component obtained from the vegetable oil of the above through a distillation and extraction process to a hydrogenation reaction treatment. The purity of commercially available 3-pentadecylphenol is usually 90% by mass or more and less than 97.5% by mass. The purity of 3-pentadecylphenol used in the present invention must be 97.5% by mass or more. Use of less than 97.5% by mass is not preferable because the YI value of the obtained polycarbonate resin molded product increases and the transparency decreases. 3-pentadecylphenol having a purity of 97.5% by mass or more can be obtained by purifying the low-purity 3-pentadecylphenol by distillation or crystallization. The highly purified 3-pentadecylphenol is in a fine needle crystal state. As for the size, the length is 200 to 300 μm, the diameter (major axis) is about 50 μm, and the bulk density has a very small value of about 0.16 g / cm ³ . When such fine powdery 3-pentadecylphenol is used, it is difficult to handle, so fine powder of 3-pentadecylphenol having a low bulk density is pressed and granulated at 30 to 48 ° C., It is preferable to use one having a bulk density of about 0.3 to 0.7 g / cm ³ . The size of the granulated product is not particularly limited, but the maximum diameter or length is preferably 0.5 to 10 mm, more preferably 0.5 to 5 mm. The shape of the granulated product is not particularly limited, but may be a cylindrical shape, a rectangular parallelepiped shape, a cubic shape, an elliptical shape, a spherical shape, a flake shape, or the like.

Since 3-pentadecylphenol is difficult to dissolve in an alkaline aqueous solution, it is preferable to use it dissolved in an organic solvent, preferably methylene chloride, when introduced into the first reaction zone. If a 3-pentadecylphenol organic solvent solution having a specific concentration is prepared in advance, the amount of introduction per unit time is constant when continuously introduced into the first reaction zone. The continuous production at is preferred. The concentration of 3-pentadecylphenol in the solution is usually preferably in the range of 5 to 35% by mass.

(Iii) Caustic alkali In order to carry out the reaction between the polycarbonate oligomer and 3-pentadecylphenol in the first reaction zone, it is necessary to keep the inside of the reaction system alkaline (caustic alkali concentration 0.05 to 0.7 N). . As the caustic used, sodium hydroxide or potassium hydroxide is preferable. Caustic is preferably introduced as an aqueous solution.
(Iv) Other raw materials In order to promote the reaction in the first reaction zone, a known catalyst used during the interfacial polymerization of the polycarbonate resin can be used. As the catalyst, a phase transfer catalyst such as a tertiary amine or a salt thereof, a quaternary ammonium salt, or a quaternary phosphonium salt can be preferably used. Examples of the tertiary amine include triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, dimethylaniline and the like, and examples of the tertiary amine salt include hydrochlorides and bromates of these tertiary amines. Etc. Examples of the quaternary ammonium salt include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, and tetrabutylammonium bromide. Examples thereof include butylphosphonium chloride and tetrabutylphosphonium bromide. These catalysts may be used alone or in combination of two or more. Among the catalysts, tertiary amines are preferable, and triethylamine is particularly preferable. These catalysts can be introduced as they are in a liquid state or dissolved in an organic solvent or water. Moreover, a solid state thing can be dissolved and introduce | transduced in an organic solvent or water.

<Reactor and reaction conditions used in the first reaction zone>
A line mixer, a static mixer, an orifice mixer, a stirring tank, etc. can be used as a reactor used in the first reaction zone, and the reaction can be carried out continuously or batchwise. These reactors may be arbitrarily combined and used as a plurality of reactors. Further, it is preferable to use a line mixer in these reactors because the reaction can be continuously carried out and the reaction can be advanced efficiently.
When a polycarbonate oligomer having a chloroformate group at the end group as a polycarbonate oligomer having a weight average molecular weight of less than 5000 is used in the first reaction zone, sodium hydroxide as a caustic alkali, and triethylamine (TEA) as a catalyst for the reaction accelerator, The preferred molar ratio of the polycarbonate oligomer having a weight average molecular weight of less than 5000, 3-pentadecylphenol (PDP), caustic alkali (NaOH), and catalyst (TEA: triethylamine) is the molar concentration of chloroformate groups in the polycarbonate oligomer ( With respect to (CF value), it is preferable that PDP / CF = 0.01 to 0.2, TEA / CF = 0.001 to 0.006, and NaOH / CF = 0.1 to 0.3. The reaction temperature is usually controlled at 10 to 30 ° C., preferably 10 to 20 ° C. The reaction pressure is usually normal pressure. Under these reaction conditions, 95% or more of 3-pentadecylphenol (PDP) reacts in the first reaction zone, and usually 50 to 95 mol%, preferably 50 to 80 mol% of all end groups are chloroformate. A polycarbonate oligomer remaining as a group can be obtained. The proportion of 3-pentadecylphenoxy groups in all terminal groups of the polycarbonate oligomer is usually set in the range of 5 to 50 mol%, preferably 20 to 50 mol%.

[Second reaction zone]
In the second reaction zone defined in the present invention, a reaction solution containing a polycarbonate oligomer having a 3-pentadecylphenoxy group at the terminal obtained from the first reaction zone, an alkali aqueous solution of dihydric phenol and caustic alkali are introduced, The reaction is performed in the second reaction zone. In the reaction in the second reaction zone, the polycarbonate oligomer and the dihydric phenol are polycondensed, and a polycarbonate resin (hereinafter referred to as PDP-PC) having 3-pentadecylphenoxy groups in at least a part of the resulting end groups. Is the target viscosity average molecular weight. Hereinafter, this second reaction zone will be described.

<Raw materials used in the second reaction zone>
(I) Reaction liquid containing a polycarbonate oligomer having a 3-pentadecylphenoxy group at the terminal The reaction liquid containing a polycarbonate oligomer having a 3-pentadecylphenoxy group at the terminal obtained from the first reaction zone described above is used. Is done.
(Ii) Alkaline aqueous solution of dihydric phenol The alkaline aqueous solution of dihydric phenol used in the second reaction zone is subjected to a polycondensation reaction with a polycarbonate oligomer having a 3-pentadecylphenoxy group at the terminal obtained from the first reaction zone. Used to increase the molecular weight.
As a dihydric phenol used, when manufacturing a polycarbonate oligomer, the dihydric phenol represented by the said General formula (1) or the dihydric phenol represented by the said General formula (1), and the said formula ( It is preferable to use together with the dihydric phenol containing the structural unit represented by 2), and bisphenol A can be mentioned as a particularly preferred dihydric phenol represented by the general formula (1).
Further, as the alkaline aqueous solution, an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide used for producing the polycarbonate oligomer can be preferably used, and caustic alkali such as sodium hydroxide or potassium hydroxide in the alkaline aqueous solution can be used. Similarly, the concentration of 1 to 15% by mass is preferably used. Similarly, the content of the dihydric phenol in the alkaline aqueous solution is selected in the range of 0.5 to 20% by mass.

(Iii) Caustic alkali In the second reaction zone, the molecular weight can be increased by reacting an alkaline aqueous solution of dihydric phenol with a polycarbonate oligomer having a 3-pentadecylphenoxy group (interfacial polycondensation reaction). In this reaction, the divalent phenol becomes an alkali metal salt in an aqueous alkali solution of dihydric phenol, and the polycarbonate oligomer chlorophore having a 3-pentadecylphenoxy group dissolved in the divalent phenol alkali metal salt and an organic solvent. The mate group is polycondensed by a desalting reaction at the interface between the organic phase and the aqueous phase to increase the molecular weight. Since this interfacial polycondensation reaction proceeds under alkalinity, it is necessary to react by adding caustic alkali such as sodium hydroxide or potassium hydroxide in order to accelerate the reaction.

The caustic alkali introduced from the inlet of the second reaction zone preferably has a concentration of 10 to 50% by mass, and the caustic alkali concentration in the aqueous phase of the reaction solution is 0.05 to 0.7 N (N) It is preferable to supply so that it becomes. The reaction rate is increased by the high concentration of caustic alkali supplied in this way, and as a result, the reaction time is shortened. In addition, a polycarbonate resin (PDP-PC) having a high blocking ratio with monohydric phenols at the polymer terminals (reducing the residual amount of hydroxyl terminal groups) and a small amount of low molecular weight can be obtained.
The caustic introduced from the inlet to the second reaction zone is the total amount of caustic used from the inlet to the second reaction zone (when using multiple reactors, the inlet of the first reactor to be used). It is necessary to introduce. When a part of caustic alkali is divided from the middle of the second reaction zone and used, when separating the resulting reaction liquid (emulsion solution containing PDP-PC) into an aqueous phase and an organic phase containing PDP-PC, When the separated organic phase is separated into an aqueous phase and an organic phase in a washing step such as alkali washing, acid washing, and water washing, it is not preferable because the separation performance deteriorates and the productivity deteriorates.

(Iv) Other raw materials From the outlet of the second reaction zone, a reaction liquid containing a polycarbonate resin after the polycondensation reaction is taken out. In addition, it can react without introduce | transducing a terminal terminator into this 2nd reaction zone. Moreover, in order to adjust the molecular weight of the polycarbonate resin after completion | finish of reaction of a 2nd reaction zone, you may add a terminal stopper (molecular weight regulator) to a 2nd reaction zone. As the terminal stopper, a known terminal stopper other than 3-pentadecylphenol can be used, and at least one terminal stopper selected from pt-butylphenol, p-cumylphenol and phenol is used. It is preferable to use it. When the end stopper is added to the second reaction zone, the molar ratio of 3-pentadecylphenol introduced into the first reaction zone to the end stopper introduced into the second reaction zone is 1: 9 to 9: 1. It is preferable to be within the range.
Moreover, in order to accelerate | stimulate a polycondensation reaction, the same catalyst used at the time of interfacial polymerization of the polycarbonate resin demonstrated in the 1st reaction zone can be used, The preferable aspect is also the same.

<Reactor and reaction conditions used in the second reaction zone>
In the second reaction zone, depending on the capacity of the reactor used, the reaction can be completed with the use of only one reactor, but if necessary, a subsequent second reactor, Can be combined with a plurality of reactors such as a third reactor to form a second reaction zone. As a reactor used in the second reaction zone, a stirring tank, a multi-stage tower type stirring tank, a non-stirring tank, a static mixer, a line mixer, an orifice mixer, a pipe, etc. can be used, and the reaction is efficiently performed. Therefore, it is preferable to use a line mixer. A plurality of these reactors may be used in any combination.

The polycarbonate resin of the present invention can be produced either continuously or batchwise. When manufacturing in a batch system, first, in the reactor used as the first reaction zone, a polycarbonate oligomer having a weight average molecular weight of less than 5000, 3-pentadecylphenol, a catalyst (TEA, etc.), caustic alkali is used. The oligomer is reacted with pentadecylphenol to produce a polycarbonate oligomer having a 3-pentadecylphenoxy group in a part of the terminal groups of the polycarbonate oligomer. Next, caustic and dihydric phenol are added to the same reactor, and the conditions of the second reaction zone (specifically, caustic concentration 0.05 to 0.7 N) may be set. That is, the reaction conditions may be adjusted using the same reactor, and the conditions for both of the first reaction zone and the second reaction zone may be set sequentially.
The temperature in the second reaction zone is preferably 20 to 35 ° C. In particular, if the temperature in the second reaction zone exceeds 35 ° C., the terminal hydroxyl group fraction of the molded product increases and the YI value of the molded product may increase.

[Process after reaction]
(I) Separation step The mixed solution after the reaction obtained from the second reaction zone is in an emulsion state, and it is necessary to separate this emulsion into an organic phase containing polycarbonate and an aqueous phase. For this purpose, an inert organic solvent such as methylene chloride is added to the mixed solution after the reaction and diluted appropriately, and then separated into an aqueous phase and an organic phase containing a polycarbonate resin by standing or centrifuging.
(Ii) Washing Step The organic phase containing the polycarbonate resin thus separated is washed with an alkaline aqueous solution, an acidic aqueous solution, pure water, or the like in order to remove impurities such as residual monomers, catalysts, and alkaline substances. . The washing mixture is separated into an organic phase containing a purified polycarbonate resin and an aqueous phase using a centrifuge or a stationary separation tank.
(Iii) Concentration step The organic phase containing the purified polycarbonate resin that has been subjected to the washing treatment is efficiently concentrated in a kneader, a powder bed granulator, a hot water granulator, etc. Preferably, it is concentrated to 10 to 45% by mass.
(Iv) Powder / granulation / drying step The organic phase containing the purified polycarbonate resin obtained in the concentration step is a known powder / granulation method such as a kneader, powder bed granulator, hot water granulator, etc. Powdered and granulated. Since the obtained powder / granulated product contains 1 to 8% by mass of the organic solvent such as methylene chloride used, the residual organic solvent is further reduced to 1000 ppm or less by drying by heating, drying under reduced pressure, or the like. Is desirable.

By the production method of the present invention, a polycarbonate resin (PDP-PC) having excellent transparency and a yellow index (YI value) of 1.1 or less is obtained. The polycarbonate resin obtained by the production method of the present invention may have a viscosity average molecular weight of 8,000 to 20,000.
The PDP-PC obtained by the production method of the present invention has a 3-pentadecylphenoxy group as a terminal group, and thus has excellent fluidity, and has a low YI value, so that it has excellent color tone and transparency. It can be suitably used for a liquid crystal member. Further, the production method of the present invention provides a method for producing a polycarbonate resin (PDP-PC) with high production efficiency because the separation is excellent when separating the reaction liquid after polymerization into an organic phase and an aqueous phase. be able to.

The polycarbonate resin (PDP-PC) obtained by the method for producing a polycarbonate resin of the present invention can be mixed with a polycarbonate resin other than PDP-PC at an arbitrary ratio to obtain a polycarbonate resin composition.
The polycarbonate resin is not particularly limited, and various known polycarbonate resins other than PDP-PC can be used.
The polycarbonate resin (PDP-PC) or the polycarbonate resin (PDP-PC) composition includes an antioxidant, an ultraviolet absorber, a flame retardant, a release agent, an inorganic filler (glass fiber, talc, Titanium oxide, mica, etc.), colorants, light diffusing agents and the like can be used according to the properties required for the intended use. The polycarbonate resin or the polycarbonate resin composition can be formed into a molded body by various molding methods such as injection molding, injection compression molding, extrusion molding, and blow molding.

The molded article formed by molding the polycarbonate resin (PDP-PC) or the polycarbonate resin (PDP-PC) composition is preferably a liquid crystal display device used for a mobile phone, a liquid crystal television, a personal computer, an electronic dictionary, an electronic book, etc. It can be set as the member for liquid crystal equipment. Since the polycarbonate resin obtained by the present invention is excellent in fluidity, it is desirable to form it by injection molding, particularly when manufacturing a thin molded body, and it is a resin for a light guide plate or a light diffusion plate of a liquid crystal display device. Can be suitably used.

Hereinafter, the present invention will be described in more detail with reference to examples. Note that the present invention is not limited to these examples. In addition, the measurement evaluation in an Example and a comparative example was performed by the method shown below.

<Method for measuring purity of 3-pentadecylphenol>
The purity of 3-pentadecylphenol was “Agilent 1200” manufactured by Agilent Technologies, Inc., “L-column ODS” (4.6 mm ID × 150 mm, particle size 3 μm) in the column, and acetonitrile / formic acid buffer in the mobile phase. = 95/5 (vol / vol).

<Measurement of viscosity average molecular weight (Mv)>
The viscosity average molecular weight (Mv) of the polycarbonate resin is obtained by measuring the viscosity of the methylene chloride solution at 20 ° C. using an Ubbelohde viscometer, obtaining the intrinsic viscosity [η] from this, and calculating by the following formula. .
[Η] = 1.23 × 10 ⁻⁵ Mv ^0.83

<Measurement of end group composition amount>
¹ H-NMR was measured using “JNM-LA500” manufactured by JEOL Ltd., and the terminal group composition amount of the polycarbonate resin was calculated.

<Measurement of flow value (Q value)>
Melting out from a nozzle with a diameter of 1 mm and a length of 10 mm in accordance with JISK7210 using a polycarbonate flow pellet used in the measurement of the YI value under a pressure of 280 ° C. and 15.7 MPa. The amount of resin (× 10 ⁻² mL / sec) was measured.

<Measurement of YI value>
Adegas tub PEP36 [bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol phosphite made by ADEKA Corporation] was added to the obtained polycarbonate resin flakes, and 40 mmφ uniaxial with a vent was added. The mixture was melt-kneaded and extruded by an extruder at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm to obtain pellets. Using the obtained pellets, a molded product having a thickness of 3 mm was molded, and measured with a spectrocolorimeter Σ90 manufactured by Nippon Denshoku Industries Co., Ltd., with a measurement area of 30φ and a C2 light source transmission method.

<Measurement of bulk density>
The bulk density was measured based on JISK7365.

Production Example 1 <Production of high-purity 3-pentadecylphenol>
A column having an inner diameter of 30 mm and a capacity of 500 mL is packed with McMahon packing (Mc. MAHON Packing, standard size: 6 mm) to form a rectifying column, which is attached to a 2 L flask equipped with an internal temperature measuring device, and a reflux ratio ( A device for adjusting the reflux amount / distillation amount), a device for measuring the tower top temperature, and a depressurization degree adjusting device were attached. 100.96 g of 3-pentadecylphenol solid (manufactured by Tokyo Chemical Industry Co., Ltd., purity 92.10% by mass) was supplied to the flask, and after replacing with nitrogen, heating and decompression were started. The degree of vacuum was set to 2 mmHg, reflux / distillation = 1, and the fraction having a tower top temperature of 205-210 ° C. was fractionated. At this time, the flask temperature was 230 to 245 ° C. The amount collected was 825.71 g (82% by mass of the charge), and the purity of 3-pentadecylphenol was 93.61% by mass.
Next, the obtained crude 3-pentadecylphenol was melted in a 60 ° C. hot water bath and weighed 70 g in a standard bottle, and 420 g of n-hexane was added and dissolved. The mixture was allowed to stand at room temperature for 12 hours, and the precipitated solid was filtered under reduced pressure, and then dried under reduced pressure at room temperature for 8 hours to obtain purified 3-pentadecylphenol as a fine powder. The purity of the purified 3-pentadecylphenol was 97.75% by mass, and the bulk density of the 3-pentadecylphenol fine powder was 0.16 g / cm ³ . 3-Pentadecylphenol fine powder with a purity of 97.75% by mass is put into a roller compactor, and after applying a load of 0.2 tons per 1 cm roll width, it is pulverized to obtain a granulated product having a maximum diameter of 3 mm. It was. The powder temperature after granulation was 23.4 ° C. The bulk density of this granulated product was 0.46 g / cm ³ .

Example 1
Manufactured using sodium hydroxide aqueous solution of bisphenol A as a polycarbonate oligomer, phosgene, methylene chloride and pt-butylphenol (PTBP), concentration 318 g / L, chloroformate group concentration 0.75 mol / L, weight average molecular weight (Mw) = 3,100, the functional group ratio of all terminal groups determined by NMR is pt-butylphenoxy group (terminal group derived from PTBP): OH: chloroformate group (CF) = 3.3: 7 7: 89.0 polycarbonate oligomer in methylene chloride (PCO) was used as the starting material.
The weight average molecular weight (Mw) was measured using GPC [column: TOSOH TSK-GEL MULTIPIORE HXL-M (2) + Shodex KF801 (1)], temperature 40 ° C., flow rate 1. It was measured as a standard polystyrene equivalent molecular weight (weight average molecular weight: Mw) at 0 ml / min, detector: RI].

This polycarbonate oligomer 20 liters / hr, a solution of 1.7 methylene chloride of 97.75% by mass of 3-pentadecylphenol (PDP) obtained in Preparation Example 1 was dissolved in methylene chloride and contained 1.7% of methylene chloride. Liter / hr (PDP / CF = 0.057), 0.04 liter / hr of 4% by weight aqueous solution of triethylamine and 1.0 liter / hr of 10% by weight sodium hydroxide aqueous solution (NaOH / CF = 0.2) At a flow rate, as a first reactor, a T.D. with an internal volume of 0.3 liter having turbine blades with a diameter of 43 mm and a diameter of 48 mm. Supply to K pipeline homomixer 2SL type (manufactured by Tokushu Kika Kogyo Co., Ltd.) [Line mixer used as the first reaction zone], react under rotation of 3000 rpm, part of the chloroformate group of polycarbonate oligomer end group Was reacted with 3-pentadecylphenol to obtain a polycarbonate oligomer reaction solution in which a part of the end groups were 3-pentadecylphenoxy groups.
The ratio of 3-pentadecylphenoxy group to all terminal groups of the polycarbonate oligomer contained in the polycarbonate oligomer reaction solution was 32 mol%, and the ratio of chloroformate group was 57 mol%. The proportion of end groups was measured by ¹ H-NMR. Further, the unreacted 3-pentadecylphenol contained in the polycarbonate oligomer reaction solution was measured by ¹ H-NMR and found to be 0.1%, and 99.7% of the supplied pentadecylphenol reacted. I confirmed. The temperature at the first reaction zone outlet (point a) was 20 ° C. The polycarbonate oligomer exiting the first reaction zone was cooled by a heat exchanger, and the temperature (point b) at the heat exchanger outlet was 15 ° C.

Subsequently, as a second reactor, a throughzer mixer (manufactured by Sumitomo Heavy Industries, Ltd.) having an inner diameter of 9.2 mm, a length of 230 mm and incorporating 14 elements [used as the first reactor in the second reaction zone] In the line mixer], the reaction solution from the outlet of the first reactor, an aqueous solution (BPA-Na) in which bisphenol A was dissolved in a 5.6 mass% sodium hydroxide aqueous solution to a concentration of 13.5 mass%. 5 liter / hr (NaOH / OH equivalent ratio = 1.03), 0.35 liter / hr (PTBP / PTBP / methylene chloride solution in which pt-butylphenol (PTBP) was dissolved as a molecular weight regulator to a concentration of 24% by mass. CF = 0.055) and 25% by mass aqueous sodium hydroxide solution 0.64 l / hr (NaOH / CF = 1.3) were introduced. The CF value at this time indicates the chloroformate group concentration of the polycarbonate oligomer used in the first reaction zone. The temperature at the outlet of the second reactor (point c) was 33 ° C.
As a third reactor for completing the reaction, it was supplied to a 50 liter jacketed, three-stage tower-type stirring tank with a paddle blade [used as the second reactor in the second reaction zone] and subjected to polycondensation. went. A 15 ° C. cooling water was passed through the jacket, and the outlet temperature of the polymerization solution was set to 35 ° C. A process diagram from the first reaction zone to the second reaction zone is shown in FIG.

This polymerization solution was allowed to stand, and was separated into an organic phase containing a polycarbonate resin and an aqueous phase containing excess bisphenol A and NaOH. When the water content in the organic phase 60 minutes after standing was measured with a Karl Fischer moisture meter, it was 2000 ppm by mass. The organic phase is washed with alkali, acid, and water (washing with pure water is repeated until the electric conductivity in the aqueous phase after washing is 0.05 μS / m or less.) Obtained as a phase.
The methylene chloride solution of the polycarbonate resin obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 100 ° C. under reduced pressure to obtain polycarbonate resin flakes. The viscosity average molecular weight of this polycarbonate resin flake was 11,500, the content of 3-pentadecylphenol derived from 3-pentadecylphenoxy group was 3% by mass, and the unreacted 3-pentadecylphenol in the flake was 9 ppm. It was. Moreover, the hydroxyl group terminal fraction with respect to all the terminal groups was 1.9 mol%. The flakes dried granulated with an extruder to pellets was measured the flow value of the pellet (Q value) was 123 × 10 -2 ^{mL /} sec. Further, a plate was formed using this pellet, and the yellow index (YI value) was measured and found to be 1.0. The obtained results are shown in Table 1.

Example 2
In Example 1, except that the methylene chloride solution of pt-butylphenol having a concentration of 24% by mass introduced into the second reaction zone was changed to 0.25 liter / hr (PTBP / CF = 0.039). 1 to obtain a polycarbonate resin. The results are shown in Table 1.

Example 3
In Example 1, a methylene chloride solution of 3-pentadecylphenol having a concentration of 12% by mass introduced into the first reaction zone was adjusted to 0.57 liter / hr (PDP / CF = 0.199) and introduced into the second reaction zone. A polycarbonate resin was obtained in the same manner as in Example 1 except that the methylene chloride solution of pt-butylphenol having a concentration of 24% by mass was changed to 0.59 l / hr (PTBP / CF = 0.093). The results are shown in Table 1.

Example 4
In Example 1, the methylene chloride solution of 3-pentadecylphenol having a concentration of 12% by mass introduced into the first reaction zone was adjusted to 3.34 liter / hr (PDP / CF = 0.112), and p-type was added to the second reaction zone. A polycarbonate resin was obtained in the same manner as in Example 1 except that -t-butylphenol was not introduced. The results are shown in Table 1.

Example 5
In Example 1, the first reaction zone was the same as in Example 1 except that a 20-liter stirred tank with a Faudler blade having a diameter of 260 mm was used as the first reactor and the operation was performed at a rotational speed of 290 rpm. The reaction was performed. Cooling was performed by passing cooling water at 15 ° C. through the jacket. In the second reaction zone, the same line mixer as that used in the first reactor of Example 1 [used as the first reactor in the second reaction zone] was used for polymerization at a rotational speed of 4000 rpm. Completed the reaction in a 30 liter vertical pot without a stirrer [used as the second reactor in the second reaction zone]. The results are shown in Table 1.

Comparative Example 1
In Example 1, instead of 3-pentadecylphenol having a purity of 97.75% by mass, a 3-pentadecylphenol solid product having a purity of 92.10% by mass (manufactured by Tokyo Chemical Industry Co., Ltd.) was used. 1, a polycarbonate resin was obtained. The results are shown in Table 1.

Comparative Example 2
In Example 1, the first reactor as the first reaction zone was stopped, and a methylene chloride solution of 3-pentadecylphenol having a concentration of 12% by mass introduced into the first reaction zone, a 4% by mass aqueous solution of triethylamine, 10% by mass. The same procedure as in Example 1 was carried out except that all the aqueous sodium hydroxide solution was introduced into the inlet of the second reaction zone (process diagram is shown in FIG. 2). The results are shown in Table 1.

Comparative Example 3
In Example 1, 25 mass% sodium hydroxide aqueous solution introduced into the second reaction zone was added at 0.25 liter / hr (Na / CF = 0.5) at the inlet of the second reactor (inlet of the second reaction zone). ) And a polycondensation reaction was carried out in the same manner as in Example 1 except that split introduction was carried out at 0.39 liter / hr (Na / CF = 0.8) at the outlet of the second reactor ( The process diagram is shown in FIG. When the obtained polymerization liquid is allowed to stand to separate into an organic phase containing a polycarbonate resin and an aqueous phase containing excess bisphenol A and NaOH, the organic phase and the aqueous phase are completely separated even after 60 minutes from standing. Not separated.

As is apparent from Table 1, in the method for producing the polycarbonate resin of the present invention of Examples 1 to 5, the separation property for separating the reaction liquid obtained after the polycondensation reaction into an organic phase and an aqueous phase is good. It is shown that the water concentration in the inside is also stable. Moreover, it turns out that the YI value which shape | molded the obtained polycarbonate resin and measured the molded article is also favorable. On the other hand, Comparative Example 1 uses 3-pentadecylphenol having a low purity, but the YI value is higher than that of the Example, indicating that the transparency is lowered. . In Comparative Example 2, the first reaction zone was not used, but the temperature in the second reaction zone was increased, the hydroxyl group terminal fraction of the obtained polycarbonate resin was increased, and the YI value of the molded product was You can see that it is getting higher. And the comparative example 3 is an example which divided and added the caustic used for a 2nd reaction zone. In Comparative Example 3, it was shown that the molded product could not be evaluated because the polymerization solution obtained after the reaction could not be separated.

The method for producing a polycarbonate resin of the present invention has good oil-water separation properties of the reaction solution after the reaction, can increase production efficiency, and can lower the YI value of the molded product. A polycarbonate resin excellent in color tone can be obtained.

Claims

In a method for producing a polycarbonate resin by reacting a polycarbonate oligomer having a weight average molecular weight of less than 5,000 with an alkaline aqueous solution of a dihydric phenol, the purity obtained from the polycarbonate oligomer or natural product is 97 at the inlet to the first reaction zone. Introducing 5% by mass or more of 3-pentadecylphenol and caustic alkali, the polycarbonate oligomer and 3-pentadecylphenol are reacted in the first reaction zone, and a part of the end group of the polycarbonate oligomer is 3-pentadecyl. Producing a reaction liquid containing a polycarbonate oligomer that is a phenoxy group, then introducing the reaction liquid obtained from the first reaction zone, an alkali aqueous solution of dihydric phenol and caustic alkali into the inlet to the second reaction zone; and Caustic fluid introduced into the second reaction zone Kali method for producing a polycarbonate resin characterized in that the reaction is carried out by introducing the total amount from the inlet of the second reaction zone in a second reaction zone.
The method for producing a polycarbonate resin according to claim 1, wherein the reaction is carried out by introducing at least one selected from pt-butylphenol, p-cumylphenol and phenol as a terminal stopper in the second reaction zone. .
The polycarbonate resin according to claim 2, wherein a molar ratio of 3-pentadecylphenol introduced into the first reaction zone and a terminal stopper introduced into the second reaction zone is 1: 9 to 9: 1. Production method.
The method for producing a polycarbonate resin according to claim 1, wherein the reaction is carried out in the second reaction zone without introducing a terminal stopper into the second reaction zone.
5. The method for producing a polycarbonate resin according to claim 1, wherein 3-pentadecylphenol is introduced into the first reaction zone as a solution dissolved in methylene chloride.
The method for producing a polycarbonate resin according to any one of claims 1 to 5, wherein the temperature of the second reaction zone is 20 to 36 ° C.
The method for producing a polycarbonate resin according to any one of claims 1 to 6, wherein 5 to 50 mol% of all terminal groups of the polycarbonate oligomer obtained from the first reaction zone are 3-pentadecylphenoxy groups.
The method for producing a polycarbonate resin according to any one of claims 1 to 7, wherein 50 to 95 mol% of all terminal groups of the polycarbonate oligomer obtained from the first reaction zone are chloroformate groups.
The method for producing a polycarbonate resin according to any one of claims 1 to 8, wherein the obtained polycarbonate resin has a viscosity average molecular weight of 8,000 to 20,000.
10. The method for producing a polycarbonate resin according to claim 1, wherein the polycarbonate oligomer having a weight average molecular weight of less than 5000 is obtained using bisphenol A.
The method for producing a polycarbonate resin according to any one of claims 1 to 10, wherein the dihydric phenol is bisphenol A.
The method for producing a polycarbonate resin according to any one of claims 1 to 11, wherein pentadecylphenol introduced into the first reaction zone is reacted at 95% or more in the first reaction zone.
The method for producing a polycarbonate resin according to any one of claims 1 to 12, wherein a line mixer is used in the first reaction zone and / or the second reaction zone.