JP2003306544A - Method for producing aromatic polycarbonate oligomer and method for producing polycarbonate resin by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aromatic polycarbonate resin which reduces the investment and the electrical energy in a refrigerator to be used for cooling and improves productivity in a method for producing an aromatic polycarbonate oligomer by the interfacial polymerization method and in the method for producing an aromatic polycarbonate resin by using the aromatic polycarbonate oligomer. <P>SOLUTION: The method for producing the aromatic polycarbonate oligomer comprises removing the heat of reaction by utilizing the latent heat of vaporization of an organic solvent to be used, cooling the evaporated organic solvent by a condenser, and simultaneously carrying out the reaction in a closed system in reacting an alkali aqueous solution of a bisphenol compound with phosgene in the presence of the organic solvent in a reactor in the method for producing the aromatic polycarbonate resin by the interfacial polymerization method, and the method for producing an aromatic polycarbonate resin uses the aromatic polycarbonate oligomer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an aromatic polycarbonate oligomer and a method for producing an aromatic polycarbonate resin using the same. More specifically, in producing an aromatic polycarbonate resin by the interfacial polymerization method, an aromatic scent that cools the reaction liquid by utilizing the latent heat of vaporization of the organic solvent in order to remove the enormous heat of reaction during the reaction between the bisphenol compound and phosgene. The present invention relates to a method for producing a group polycarbonate oligomer and a method for producing an aromatic polycarbonate resin using the same.

[0002]

2. Description of the Related Art A method for producing an aromatic polycarbonate resin by an interfacial polymerization method is to stir a mixture of an alkaline aqueous solution of bisphenol and methylene chloride,
When phosgene is blown into this in a gaseous form, a low-molecular-weight polycarbonate having a chloroformate end group is first produced in the solvent, but the reaction between the alkali salt of bisphenol and phosgene is fast and is an exothermic reaction. A large amount of cooling water was required to control the reaction temperature. Further, in terms of decomposition of phosgene and hue of the obtained aromatic polycarbonate resin, it was necessary to keep the reaction temperature at a low temperature of about 20 ° C.

An alkaline aqueous solution of bisphenol and an organic solvent for a polycarbonate oligomer are introduced into a tubular reactor to form a multiphase flow, and phosgene is cocurrently reacted with this, and the heat of reaction generated at that time is temporarily generated from the organic solvent. Japanese Patent Publication No. 46-21460 discloses a continuous method for producing a polycarbonate oligomer which is removed by heat of vaporization.
However, in this method, the reaction is a cocurrent reaction in a tubular reactor and no stirring is performed. In addition, the tubular reactor is a double tube, and cooling water is passed through the jacket, but the heat of reaction generated is temporarily removed by the heat of vaporization of the organic solvent, and most of the heat of reaction is Is removed by cooling water in the jacket. Furthermore, the method requires gas-liquid separation of the reaction product, which makes the operation and the apparatus complicated.

Therefore, in JP-A-58-108225, in a method for producing a polycarbonate oligomer by reacting an alkaline aqueous solution of a dioxy compound with phosgene in the presence of an organic solvent, the reaction is carried out at 2 to 20 ° C. A method of attaching a cooling jacket to the reaction tube in order to maintain the temperature range has been proposed, but in order to perform cooling efficiently, it is necessary to reduce the tube diameter, and then the reaction of fog droplets with gas in the reaction tube. There is a dilemma that it becomes difficult to proceed smoothly. Also, this method also requires a refrigerant of 0 ° C. or lower in order to maintain a low temperature.

On the other hand, as a method for removing the heat of reaction generated during the reaction, a method of bringing the initial reaction product into contact with a large amount of the reaction product maintained at a constant temperature is disclosed in Japanese Examined Patent Publication No. 54-4.
No. 0280 is proposed. However, with this method, it is difficult to control the initial stage of the phosgenation reaction, and it is difficult to avoid decomposition of phosgene and chloroformate.

Further, a method of keeping an alkaline aqueous solution of bisphenol at 0 ° C. or lower and reacting the cold aqueous solution with phosgene to effectively absorb reaction heat is disclosed in JP-A-55-5.
It is proposed in Japanese Patent No. 2321. However, in this method, the reaction temperature can be kept low, but at such a low temperature, when methylene chloride most often used as an organic solvent comes into contact with an aqueous solution, a hydrate is formed and the reaction system becomes sherbet-like, Various inconveniences occurred and it was unsuitable for practical use.

As a method for removing such heat of reaction, a continuous production method of a polymer linear polycarbonate in which a cooled high molecular weight reaction mixture is re-supplied is proposed in JP-A-47-14297. Since phosgene is diluted with other inert gas and charged, the reaction product must be separated into gas and liquid, and since amine is present and the system is easily in an emulsified state, decomposition of phosgene and chloroformic acid ester does not occur. Rather, there was a problem of growing.

The removal of the heat of reaction generated in the phosgenation reaction (polycarbonate oligomer formation reaction) of an aromatic polycarbonate resin has hitherto been carried out in the interfacial reaction because of the problems of decomposition of phosgene, blowout of phosgene, and volatilization of the reaction solvent. The reaction temperature was around 20 ° C. Therefore, in order to remove the heat of reaction, a method of flowing a refrigerant through a jacket or an internal coil or a method of externally circulating the reaction solution and cooling with a heat exchanger is adopted. However, in the case of these methods, since a refrigerant of 0 ° C. or lower is required as the refrigerant,
A refrigerator was required to manufacture the refrigerant, and the load of electric energy was very large.

[0009]

The object of the present invention is to solve the above-mentioned problems in the prior art and to reduce the capital investment and electric energy of the refrigerator used for cooling in the production of polycarbonate resin. A method for producing an aromatic polycarbonate oligomer having improved productivity and a method for producing an aromatic polycarbonate resin using the same are provided.

[0010]

Means for Solving the Problems The inventors of the present invention have variously studied a method of utilizing latent heat of vaporization of an organic solvent to remove heat of reaction in the production of an aromatic polycarbonate oligomer. When methylene chloride is used, the reaction temperature is around 40 ° C, and the cooling water around 20 ° C cooled in the cooling tower can be used as the refrigerant, but it is extremely difficult to completely condense the organic solvent in the condenser. Needed a large condenser. Therefore, it was found that if the waste gas discharged from the condenser is returned to the reactor, the organic solvent and blown-out phosgene can be recovered without making the condenser so large,
The present invention has been completed. That is, in the present invention, the reaction system is closed until the end of blowing phosgene to produce an aromatic polycarbonate oligomer, and then the boiling point of the organic solvent is 5 ° C.
After the reaction liquid is cooled to the above low temperature, an alkaline aqueous solution and a polycondensation catalyst are added to carry out polycondensation to a desired molecular weight.

Further, in the present invention, in order to prevent phosgene from entering the reactor through the condenser through the waste gas return pipe, a check valve and / or a gas circulation pump is provided in the waste gas return pipe. It is characterized by

Further, in the present invention, it has been found that when phosgene is blown in, the pH of the aqueous phase is controlled to be 10 to 12 so that the decomposition of phosgene by alkali can be suppressed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION That is, the present invention relates to (a) a phosgene gas blowing pipe, a reflux condenser for an organic solvent, and a pipe for returning waste gas disposed above the condenser to a reactor (however, the condenser is used). Can be omitted if the upper part of the above is sealed.), The alkaline aqueous solution of the bisphenol compound and the liquid organic solvent are put into a tank reactor equipped with a stirrer and a cooling jacket, and (b) the liquid is stirred. After the mixture is formed, (c) phosgene is blown into the liquid mixture through a phosgene gas blowing tube while stirring to react the bisphenol compound with phosgene, and (d) utilizing latent heat of vaporization of the liquid organic solvent. , The heat of reaction generated by the reaction is removed by cooling, (e) the evaporated organic solvent is condensed by the reflux condenser and returned to the reactor, and contains uncondensed organic solvent vapor. Gas, back to the reactor through a pipe returning to the reactor, whereby (f), to obtain a reaction liquid comprising an aromatic polycarbonate oligomer, and (g)
Provided is a method for producing an aromatic polycarbonate oligomer, which comprises cooling a reaction liquid containing the aromatic polycarbonate oligomer by passing water through a cooling jacket.
Further, the present invention, the reaction solution containing the aromatic polycarbonate oligomer obtained by the above-mentioned production method, in the tank reactor or the reflux condenser for organic solvent, a tank reactor equipped with a stirrer and a cooling jacket , Further liquid organic solvent, alkaline aqueous solution, molecular weight modifier and polymerization catalyst are added and stirred, and while passing water through the reflux condenser for organic solvent and the cooling jacket, the polycondensation reaction is continued and the aroma is obtained by the interfacial polymerization method. Provided is a method for producing an aromatic polycarbonate resin to obtain a group polycarbonate resin.

As the bisphenol compound used in the present invention, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) is particularly preferable. Other bisphenols include, for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4 -Hydroxyphenyl) pentane, 2,2-
Bis (4-hydroxyphenyl) hexane, 2,2-bis (4-
Hydroxyphenyl) 4-methylpentane, 1,1-bis (4-
Hydroxyphenyl) 1-phenylethane, 1,1-bis (4-
Hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-
Examples thereof include hydroxyphenyl) hexafluoropropane and 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane.

Particularly, as the raw material used in the present invention, a bisphenol compound having a molten Hazen color number of 50 or less after 4 hours of melting is preferable. For example, by using a bisphenol A having a melt Hazen color number of 50 or less, more preferably 30 or less,
Even if the reaction is carried out at 0 ° C., the obtained aromatic polycarbonate resin has the same color tone as that produced at the conventional reaction temperature.

The above bisphenol compound is used by dissolving it in an alkaline aqueous solution. As the alkali, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferably used. The concentration is adjusted to control the pH of the alkaline aqueous solution of the reaction to 10 to 12,
5-10% by weight is preferred.

When blowing phosgene, the pH of the aqueous phase
Is controlled to be 10 to 12, preferably 10 to 11, and the molar ratio of the bisphenol compound to the alkali is preferably 1: 1.9 to 1: 3.2, and more preferably 1: 2.0 to 1 : 2.5 is preferable. When preparing these solutions, it is necessary to keep the temperature at 20 ° C. or higher, but if the temperature is too high, the bisphenol compound will be oxidized, so it is necessary not to raise the temperature more than necessary. It is essential to completely dissolve the bisphenol compound in order to control the pH of the aqueous phase to 10-12. For the purpose of preventing the oxidation of the bisphenol compound, it is preferable to dissolve the bisphenol compound in the alkaline aqueous solution in a nitrogen atmosphere or to add a small amount of a reducing agent such as hydrosulfite.
During the formation reaction of the polycarbonate oligomer, p
Since H is controlled by the production of sodium chloride and sodium carbonate, it is essential to adjust the pH before blowing phosgene to 11-12.

Since the gas phase portion of the reactor, the condenser of the organic solvent, the check valve and the waste gas pipe are likely to come into contact with phosgene gas, it is preferable to use a material having excellent corrosion resistance. It is preferable in terms of the hue of the obtained aromatic polycarbonate resin.

Ni is used as a material having excellent corrosion resistance.
Stainless steel containing 1% by weight or more and 16% by weight or more of Cr, nickel alloy containing 50% by weight or more of Ni,
Mention may be made of titanium alloys, Teflon, glass and ceramics. Specifically, SUS31
7, SUS317L, SUS309S, SUS310
At least one selected from S, Monel alloy, Inconel alloy, Hastelloy alloy, Chromet alloy, Titanium, Titanium alloy, Zirconium, Zirconium alloy, Teflon (registered trademark), glass and ceramic can be mentioned.

Further, as the organic solvent used, methylene chloride is preferable in terms of boiling point, latent heat of vaporization and the resulting aromatic polycarbonate resin being well dissolved. The methylene chloride is recovered and reused, but the amount of carbon tetrachloride in the methylene chloride is 50 ppm or less, preferably 20 ppm or less. The organic solvent is used in an amount of 0.1 to 1 liter per mol of bisphenol.

Phosgene is usually 100 to 120 mol, preferably 105, relative to 100 mol of bisphenol A.
Used in the range of up to 115 moles. The phosgene used in the present invention has a carbon tetrachloride content of 100 p in the phosgene from the viewpoint of the color tone of the resulting aromatic polycarbonate resin.
It is preferably pm or less, more preferably 50 ppm or less. Carbon tetrachloride in phosgene is not preferred because it accumulates in methylene chloride as a solvent. The blowing time of phosgene is usually 10 to 120 minutes, preferably 15 to 60 minutes. However, since the present invention utilizes the latent heat of vaporization of the organic solvent using the removal of the heat of reaction, it is necessary to adjust the blowing rate of phosgene depending on the capacity of the condenser of the organic solvent used. Considering the organic solvent used, the reaction temperature is preferably 30 to 50 ° C.

The present invention reduces the utility without affecting the hydrolysis of phosgene or the hue of the resulting aromatic polycarbonate resin by utilizing the latent heat of vaporization of the solvent to remove the heat of reaction by blowing phosgene. The purpose is, as the reaction solvent to be used,
Dichloromethane is preferred. The reactor is provided with a condenser for condensing the solvent. However, since the waste gas of the condenser may contain a solvent such as dichloromethane, the waste gas is used in the present invention. The method of returning to is applied. That is, after the completion of blowing phosgene, the reaction mixture is cooled to a temperature lower than the boiling point of the organic solvent by 5 ° C. or more,
A method of carrying out the reaction in a closed system is applied. Further, by returning the waste gas to the reactor through the check valve and / or the gas circulation pump, there is an effect of preventing backflow of the waste gas of phosgene from the return pipe. Further, it is also a preferable embodiment that the waste gas return pipe is connected to a phosgene blowing pipe via a gas circulation pump.

The check valve for preventing phosgene backflow and / or the gas circulation pump installed in the pipe for returning the waste gas from the outlet of the condenser to the reactor has a simple structure and keeps the pressure in the reaction system constant. A check valve is preferable because it is easy, but a fan-type gas circulation pump can also be used. When using a gas circulation pump, it is preferable to attach pressure sensors to the inlet and outlet of the gas circulation pump and control so that the pressure difference is 5 to 500 mmAq. However, it is also possible to use a check valve together instead of controlling.

In the present invention, after the completion of blowing phosgene, when the reaction mixture is cooled to a temperature lower than the boiling point of the organic solvent used by 5 ° C. or more, an alkaline aqueous solution, a molecular weight modifier and a polymerization catalyst are added. Then, the polycondensation reaction is continued until the desired molecular weight is reached.

Examples of the molecular weight modifier include monohydric phenols such as phenol, pt-butylphenol, 2,4,6-tribromophenol, and long-chain alkylphenol, as well as aliphatic carboxylic acid chloride and aliphatic Examples thereof include carboxylic acid, hydroxybenzoic acid alkyl ester, and alkyl ether phenol. Alternatively, two or more kinds of these compounds may be used in combination. The addition amount of the molecular weight modifier is 0.01 to 0.1 mol with respect to 1 mol of the charged dihydric phenol. The molecular weight modifier may be supplied in a molten state or may be dissolved in the solvent used for the reaction and supplied.

According to the present invention, the temperature of the condenser surface (heat exchanger) for liquefying the solvent evaporated during the reaction and the temperature of the brine for cooling are preferably those having a heat capacity enough to absorb heat energy. Yes, the temperature of the brine is preferably 5 ° C. to 15 ° C. lower than the boiling point of the solvent, and the higher the temperature of the brine, the larger the heat transfer surface of the heat exchanger becomes, which requires the installation of a large heat exchanger. Absent.

After addition of the molecular weight regulator, 20 to 20
The polymerization is completed using the polymerization catalyst with stirring for 120 minutes. Examples of the polymerization catalyst for the interfacial polymerization method used in the present invention include tertiary amines such as triethylamine, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, nitrogen-containing heterocyclic compounds and salts thereof, imino ethers and A salt or a compound having an amide group is used. Of these, tertiary amines such as triethylamine are preferred. The addition amount of the polymerization catalyst is 0.1 to 10 mmol with respect to 1 mol of the charged dihydric phenol.

The alkali aqueous solution to be added together with the molecular weight regulator is generally 0.2 to 1.0 mol, preferably 0.3, as an alkali, based on 1 mol of the charged dihydric phenol.
~ 0.8 mol.

The aromatic polycarbonate resin obtained in the present invention has a viscosity average molecular weight (Mv) of 10,000 to 5
10,000, preferably 13,000 to 40,0
00.

In the production method of the present invention, both a continuous method and a batch method are applied, but the batch method is preferable. When the polycarbonate resin of the present invention is used in a batch process, a conventional stirrer, a phosgene supply pipe, a condenser (heat exchanger) for organic solvents, and a waste gas to a reactor through a check valve in the upper part of the condenser. A jacketed reaction kettle with return piping is used. The stirring device is not particularly limited and may be a paddle type turbine blade, a max blend type, a full zone type, a reciprocating reversing type, or the like, but a reversing type stirring device is preferable.

[0031]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

[Measurement of Residual Melt Hue of Bisphenol A] A test tube containing 10 g of bisphenol A was set in an aluminum block bath maintained at 175 ° C., and the molten Hazen hue was measured 4 hours after melting. Was compared with the APHA standard solution to obtain a numerical value.

[Measurement of Viscosity Average Molecular Weight and Molecular Weight Distribution] The viscosity average molecular weight (Mv) is measured by a Waters GPC device (column: Waters Ultra Styler Gel 1).
0 ⁵ +10 ⁴ +10 ³ + 500Å) was used and polystyrene was used as a standard polymer, and then the relationship between the elution time and the molecular weight of the polycarbonate was determined by the universal calibration method to obtain a calibration curve. The elution curve of the polycarbonate was measured under the same conditions as in the case of the calibration curve, and each average molecular weight (viscosity average molecular weight) was determined from the elution time (molecular weight) and the peak area (proportional to the number of molecules) of the elution time. The molecular weight distribution was determined by calculating the weight average molecular weight (Mw) / number average molecular weight (Mn) obtained in the above analysis.

[Measurement of Content of Low-Molecular Weight Material] The content of the low-molecular weight material is determined by LC device manufactured by Waters (column: Sho
The measurement was performed using K803 × 2 manufactured by dex. For the elution curve (peak area) of the sample polycarbonate,
The content of the molecular weight smaller than the trimer was determined from the ratio of the peak area of the low molecular weight (less than trimer) to the elution curve (peak area) of the sample polycarbonate obtained by the above method.

[Measurement of CL Group Amount at Resin End] The amount of the chloroformate group at the resin end is measured by using a spectrophotometer in a colorimetric method using 4- (4′-nitrobenzyl) pyridine. The basis weight was measured.

[Measurement of the amount of OH groups at the resin end] The amount of phenolic hydroxyl groups at the resin end is determined by colorimetrically measuring the reddish brown color produced by reaction with titanium tetrachloride using a spectrophotometer to determine the amount of OH groups at the resin end. Was measured.

[Measurement of YI of molded product] The hue was pelletized by an extruder, and then a molded product having a thickness of 3 mm was molded by a molding machine having a mold clamping force of 50 tons manufactured by Japan Steel Works, and YI was measured by a color difference meter. It was measured.

[Measurement of Phosgene Decomposition Rate] For the phosgene decomposition rate, the phosgene decomposition rate was obtained by analyzing the amount of sodium carbonate and the amount of sodium chloride in the aqueous phase in which the polymerization was completed.

[Measurement of Weight-Average Molecular Weight of Aromatic Polycarbonate Oligomer] GPC apparatus manufactured by Waters (column: Ultrastyra Gel 10 ⁵ manufactured by Waters)
+10 ⁴ +10 ³ + 500Å) was used and polystyrene was used as a standard polymer, and then the relationship between the elution time and the molecular weight of the polycarbonate was determined by the universal calibration method to obtain a calibration curve. The elution curve of the polycarbonate oligomer was measured under the same conditions as in the case of the calibration curve, and the weight average molecular weight (Mw) was determined by calculation from the elution time (molecular weight) and the peak area of the elution time (proportional to the number of molecules). .

[Loss rate of methylene chloride] The ratio of methylene chloride recovered from the condenser and the adsorption tower in the waste gas line cooled to −20 ° C. with respect to the methylene chloride used in the reaction.

Example 1 A stirrer, a phosgene gas blowing pipe, a condenser for organic solvent (Hasterloy C heat exchanger), and a pipe for returning waste gas to the reactor via a check valve were attached to the upper part of the condenser. In a jacketed 3,000 L glass-lined reaction kettle,
950 liters of 8.8% (W / V) sodium hydroxide, 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 45 and 600 g of hydrosulfite were added and stirred. did. The pH of the mixture at this time was 11.0. Add 300 liters of methylene chloride to this and stir with phosgene 9
9 kg was blown in over 30 minutes. Six minutes after blowing phosgene, when the temperature of the reaction mixture reached 30 ° C., the closed system was opened and 100 ml of the reaction mixture was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase is 10.5.
Met. Thereafter, while stirring, 8.1 kg of pt-butylphenol, 30 liters of methylene chloride, and 200 liters of 8.8% (W / V) sodium hydroxide were added, and the mixture was continuously stirred for 6 minutes. Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the condenser and the jacket were flushed with 20 ° C. cooling water.

The polymerization solution is separated into an aqueous phase and an organic phase, the organic phase is neutralized with phosphoric acid, and the washing solution is repeatedly washed with pure water until the electric conductivity of the washing solution becomes 1 μm / S, and then a microfiltration filter. The organic phase was filtered at. The purified resin liquid was added to warm water, wet pulverized with a disintegrator, and then the solidified product was recovered and dried in a 140 ° C. dryer for 6 hours.

The polymer of the aromatic polycarbonate resin was measured for viscosity average molecular weight (Mv) using a GPC analyzer.
The molecular weight distribution (Mw / Mn) was determined. Low molecular weight content was determined by LC analysis. In addition, the amount of resin terminal Cl groups and the amount of resin terminal OH groups were determined by a colorimetric method. The results are shown in Table 2. The powder obtained in the above experiment was pelletized by an extruder at a resin temperature of 270 ° C. The obtained pellets were molded with a molding machine at a resin temperature of 310 ° C. and a mold temperature of 11
After performing a 5-shot injection molding of a molding plate having a thickness of 3 mm at 0 ° C., YI was measured by a color difference meter. The results are shown in Table 2.

Example 2 A stirrer, a phosgene gas blowing pipe, a condenser for organic solvent (Hasteloy C heat exchanger), and a pipe for returning waste gas to the reactor via a check valve were attached to the upper part of the condenser. In a jacketed 3,000 L glass-lined reaction kettle,
950 liters of 8.8% (W / V) sodium hydroxide, 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 30 and 600 g of hydrosulfite were added and stirred. did. The pH of the mixture at this time was 11.0. Add 300 liters of methylene chloride to this and stir with phosgene 9
9 kg was blown in over 30 minutes. Six minutes after blowing phosgene, when the temperature of the reaction mixture reached 30 ° C., the closed system was opened and 100 ml of the reaction mixture was sampled. Table 1 shows the measurement results of the weight average molecular weight, the low molecular weight content and the phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reaction box and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer. Indicated. The pH of the reaction liquid aqueous phase is 10.6.
Met. Thereafter, while stirring, 8.1 kg of pt-butylphenol, 30 liters of methylene chloride, and 200 liters of 8.8% (W / V) sodium hydroxide were added, and the mixture was continuously stirred for 6 minutes. Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the condenser and the jacket were flushed with 20 ° C. cooling water. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Example 3 Waste gas was reacted through a stirrer, a phosgene gas blowing tube, a condenser for organic solvent (Hasterloy C heat exchanger) and a gas circulation pump (maximum pressure difference: 100 mmAq) above the condenser. With jacket that comes with piping to return to the vessel 3,
8,000% (W / V) in a 000L glass-lined reaction kettle
950 liters of sodium hydroxide, 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 30 and 600 g of hydrosulfite were added and stirred. The pH of the mixture at this time is 1
It was 1.0. To this, 300 liters of methylene chloride was added, and 99 kg of phosgene was blown thereinto over 30 minutes while stirring. Six minutes after blowing phosgene, when the temperature of the reaction mixture reached 30 ° C., the closed system was opened and 100 ml of the reaction mixture was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase was 10.4. Then, while stirring, pt-butylphenol was added to 8.1.
kg, methylene chloride 30 liters, and 8.8%
200 liters of (W / V) sodium hydroxide was added, followed by stirring for 6 minutes. Then methylene chloride 270
L and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour to polymerize. In this reaction, the condenser and the jacket were flushed with 20 ° C. cooling water. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Example 4 A stirrer, a phosgene gas blowing tube, a condenser for organic solvent (Hasteloy C heat exchanger), and a pipe for returning waste gas to the reactor via a check valve were attached to the upper part of the condenser. In a jacketed 3,000 L glass-lined reaction kettle,
950 liters of 8.8% (W / V) sodium hydroxide, 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a melting Hazen color number of 25 and 600 g of hydrosulfite were added and stirred. did. The pH of the mixture at this time was 11.0. Add 300 liters of methylene chloride to this and stir 99 while stirring.
Blow in over 30 minutes. After blowing phosgene,
After 6 minutes, when the temperature of the reaction mixture reached 30 ° C,
The closed system was opened and 100 ml of the reaction solution was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase was 10.5. Then, while stirring, p melted at 110 ° C
8.1 kg of -t-butylphenol, 30 liters of methylene chloride, and 200 liters of 8.8% (W / V) sodium hydroxide were added, and the mixture was continuously stirred for 6 minutes.
Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the condenser and jacket were
C. cooling water was run through. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1 An experiment was carried out in the same manner as in Example 1 except that the upper part of the condenser was connected to a waste gas line and the phosgenation reaction was carried out in an open system at the time of blowing phosgene. The pH of the mixture at the time of charging was 11.0, and the pH of the reaction solution aqueous phase after the completion of blowing phosgene was 10.7. The results are shown in Tables 1 and 2.

Comparative Example 2 3,0 with jacket equipped with stirrer and gas blowing tube
In a 00 L glass-lined reaction kettle, 950 liters of 8.8% (W / V) sodium hydroxide are melted, and 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 70. And 600 g of hydrosulfite were added and stirred. The pH of the mixture at this time is 1
It was 1.0. To this, 300 liters of methylene chloride was added, and 99 kg of phosgene was blown thereinto over 30 minutes while maintaining the solution temperature at 20 ° C while stirring. Six minutes after blowing phosgene, the closed system was opened, and the reaction solution 1
00 ml was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase was 10.6. Then, while stirring, 8.1 kg of pt-butylphenol, 30 liters of methylene chloride, and 200 liters of sodium hydroxide of 8.8% (W / V) were added, and the temperature of the reaction mixture was 20 to
It was subsequently stirred at 24 ° C. for 6 minutes. Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the temperature of the refrigerant passed through the jacket is -25 ° C. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 3 3,0 with jacket equipped with stirrer and gas blowing tube
In a 00 L glass-lined reaction kettle, 950 liters of 8.8% (W / V) sodium hydroxide are melted, and 4 hours after melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 30. And 600 g of hydrosulfite were added and stirred. The pH of the mixture at this time is 1
It was 1.0. To this, 300 liters of methylene chloride was added, and 99 kg of phosgene was blown thereinto over 30 minutes while maintaining the solution temperature at 20 ° C while stirring. Six minutes after blowing phosgene, the closed system was opened, and the reaction solution 1
00 ml was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase was 10.5. Then, while stirring, 8.1 kg of pt-butylphenol, 30 liters of methylene chloride, and 200 liters of sodium hydroxide at 8.8% (W / V) were added, and the temperature of the reaction mixture was 20 to
It was subsequently stirred at 24 ° C. for 6 minutes. Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the temperature of the refrigerant passed through the jacket is -25 ° C. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Example 5 A stirrer, a phosgene gas blowing pipe, a condenser for organic solvent (Hasterloy C heat exchanger), and a pipe for returning waste gas to the reactor via a check valve were attached to the upper part of the condenser. In a jacketed 3,000 L glass-lined reaction kettle,
1020 liters of 8.8% (W / V) sodium hydroxide,
Four hours after the melting, 210 kg of 2,2-bis (4-hydroxyphenyl) propane having a molten Hazen color number of 45 and 600 g of hydrosulfite were added and stirred. The pH of the mixture at this time was 12.0. To this, 300 liters of methylene chloride was added, and 99 kg of phosgene was blown thereinto over 30 minutes while stirring. Six minutes after blowing phosgene, when the temperature of the reaction mixture reached 30 ° C., the closed system was opened and 100 ml of the reaction mixture was sampled. The results of measurement of the weight average molecular weight, low molecular weight content and phosgene decomposition rate of the polycarbonate oligomer in this reaction solution, the pressure in the reactor and the amount of electricity required for cooling to produce 1 kg of the polycarbonate oligomer are shown in Table 1. It was shown to. The pH of the reaction liquid aqueous phase is 11.6.
Met. Thereafter, while stirring, 8.1 kg of pt-butylphenol, 30 liters of methylene chloride, and 150 liters of sodium hydroxide of 8.8% (W / V) were added, and the mixture was continuously stirred for 6 minutes. Then, 270 liters of methylene chloride and 1.29 mol of triethylamine were added, and the mixture was stirred for about 1 hour for polymerization. In this reaction, the condenser and the jacket were flushed with 20 ° C. cooling water. The subsequent treatment, analysis and evaluation method were carried out in the same manner as in Example 1, and the results are shown in Table 1.

[0051]

[Table 1]

[Table 2]

[0052]

Industrial Applicability The method for producing an aromatic polycarbonate oligomer of the present invention makes it possible to utilize the latent heat of vaporization of a solvent as a method for removing the heat of reaction without losing the organic solvent used. , Manufacturing cost, running cost and productivity are greatly improved. Further, by applying the production method, a method for producing an aromatic polycarbonate resin is provided without affecting the hydrolysis of phosgene and the hue of the polycarbonate resin.

Continued front page    (72) Inventor Toshiaki Asao             35, Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture             Kashima Factory F term (reference) 4J029 AA09 AB05 AC01 AD01 AD03                       BB12A BB12C BB13A BB13B                       BD09A BG08X BG08Y HA01                       HC01 JC031 KA01 KE11

Claims (12)

[Claims] 1. In the production of a polycarbonate resin by an interfacial polymerization method, when the alkaline aqueous solution of a bisphenol compound and phosgene are reacted in the presence of an organic solvent in a reactor, the latent heat of vaporization of the organic solvent used is utilized. A method for producing an aromatic polycarbonate oligomer, characterized in that the heat of reaction is removed, the evaporated organic solvent is cooled in a condenser, and the reaction is carried out in a closed system. 2. The method for producing an aromatic polycarbonate oligomer according to claim 1, wherein waste gas is returned from the condenser to the reactor through a pipe. 3. The method for producing an aromatic polycarbonate oligomer according to claim 1, wherein a check valve and / or a gas circulation pump is provided in a pipe for returning the waste gas to the reactor, the pipe being provided at an upper portion of the condenser. 4. The method for producing an aromatic polycarbonate oligomer according to claim 1, wherein the organic solvent used is methylene chloride. 5. The bisphenol compound is 2,2-bis (4-hydroxyphenyl) propane.
A method for producing the aromatic polycarbonate oligomer described. 6. When the phosgene is blown in, the p of the aqueous phase is
The method for producing an aromatic polycarbonate oligomer according to claim 1, wherein H is controlled so as to be 10 to 12. 7. The reaction temperature is 30 to 50 ° C.
A method for producing the aromatic polycarbonate oligomer described. 8. The amount of carbon tetrachloride in phosgene is 100.
It is below ppm, The manufacturing method of the aromatic polycarbonate oligomer of Claim 1. 9. The aromatic polycarbonate according to claim 1, wherein the gas phase portion of the reactor, the condenser of the organic solvent, the check valve, the inside of the gas circulation pump and the waste gas pipe are made of a material having excellent corrosion resistance. Method for producing oligomer. 10. An aromatic polycarbonate resin for polycondensing a reaction solution containing the aromatic polycarbonate oligomer obtained in claim 1 to a desired molecular weight by further adding an organic solvent, an alkaline aqueous solution and a polycondensation catalyst. Production method. 11. The method for producing an aromatic polycarbonate resin according to claim 10, wherein the polymerization catalyst is triethylamine. 12. The method for producing an aromatic polycarbonate resin according to claim 10, wherein the organic solvent is methylene chloride.