JP3475980B2 - Continuous production method of optical polycarbonate resin - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous process for producing an optical polycarbonate resin containing a small amount of low molecular weight substances. Polycarbonate resin is used as a raw material for optical discs and compact discs for reading signals by reflecting or transmitting laser light. By using the optical polycarbonate resin having a small amount of low molecular weight product obtained in the present invention, it is possible to reduce the stain of the stamper generated at the time of disk molding and suppress the occurrence of white spots in the molded product under a high humidity and high temperature environment. Therefore, the optical polycarbonate resin according to the present invention is particularly useful as a raw material for optical discs and compact discs.

[0002]

2. Description of the Related Art Generally, a polycarbonate resin is used as a substrate material for optical information disks, a molding material for optical parts such as lenses and fibers by taking advantage of its characteristics such as transparency, heat resistance and dimensional stability. Particularly, as the optical information recording material, high-purity polycarbonate is required from the viewpoints of durability of the recording film, durability of the polycarbonate substrate itself, and prevention of stamper contamination during substrate production. The inventors of the present invention have little dirt on the stamper when molding the disc,
As a result of diligent study to obtain a polycarbonate resin that has few white spots in the substrate when the molded product is exposed to high humidity and high temperature, as a result of contamination of the stamper and white spots under high humidity and high temperature, the interface A low molecular weight substance remains in the polycarbonate resin produced by the polymerization method, and the volatile matter of this low molecular weight substance causes stains on the stamper during the molding of the optical disc substrate, which significantly increases the productivity for maintenance. It was found that there is a problem that it may fall off or the transferability of pits may deteriorate. Furthermore, this low molecular weight compound is an oligomer produced by reacting a raw material monomer: endcapping agent at a ratio of 1: 1 or a monomer oligomer produced by reacting at a ratio of 1: 2, an endcapping agent. It has been found that the dimer and the like are the most problematic among them, and the one having a high content in the polymer is a monomer oligomer.

Here, the interfacial polymerization method for obtaining a polycarbonate resin is a mixture of a methylene chloride solution of a polycarbonate oligomer obtained by phosgenation of an aqueous caustic alkali solution of a dihydric phenol, a caustic alkali and a terminal terminator (molecular weight modifier). This is a method of promoting a polymerization reaction by adding a catalyst to the solution. In such an interfacial polymerization method, unreacted dihydric phenol or a chloroformate of dihydric phenol remains in the aqueous phase after the phosgene reaction, and as described above, during the polymerization reaction, It is considered that the unreacted dihydric phenol and the like react with the terminal terminator to form a monomer oligomer. Therefore, it is difficult to avoid formation of a monomer oligomer in the conventional interfacial polymerization method, and it has been known that the content of the monomer oligomer is usually 1% by weight or more in the polymer.

Japanese Patent Publication No. 6-23243 discloses a method for reducing low molecular weight substances produced during the polymerization reaction.
It describes a method of regulating the timing of charging raw materials and the caustic concentration during the polymerization reaction. However, with this method, the reduction rate of low molecular weight substances is not yet sufficient. Further, in JP-A-6-336522, when the molecular weight of the polycarbonate oligomer, the content of the bishaloformate compound of the aromatic dihydroxy compound, and the like reach desired values, a molecular weight regulator is added to
There is a description of how to reduce the content of low molecular weight oligomers. However, it is difficult to constantly monitor the molecular weight of the polycarbonate oligomer and the content of the bishaloformate compound of the aromatic dihydroxy compound. Further, in JP-A-3-109420, a tubular reactor is used at the time of phosgenation reaction, and a molecular weight regulator is added in the tubular reactor or at the outlet of the tubular reactor. Methods for reducing the production of oligomeric oligomers are described. However, even with this method, the reduction rate of the above-mentioned monomer oligomer is not sufficient.

Further, as a method similar to the present invention, Japanese Patent Laid-Open Nos. 50-22089 and 6-100685 describe a method of using a tubular reactor during the polymerization reaction. , No description of low molecular weight substances is found.

On the other hand, as a method for removing low molecular weight substances from the produced polymer, JP-A-63-278929, JP-A-64-6020 and JP-A-4-3062 are known.
No. 27, etc. describe a method of extracting a low molecular weight substance from a polycarbonate powder with acetone. However, once the apparatus is large to extract the low molecular weight substance from the polycarbonate powder generated by granulation, and the process of removing the dissolved low molecular weight substance from the used acetone is complicated, resulting in cost increase. In addition, since the extraction ratio of low molecular weight substances when performing acetone extraction differs depending on the difference in the specific surface area of the powder, it has a drawback that the average molecular weight of the obtained powder varies. Not a method.

[0007]

Therefore, in the above-mentioned interfacial polymerization method, a new method of suppressing the formation of low molecular weight substances during the polymerization reaction is not a method of removing the low molecular weight substances in the produced polymer. Development was needed.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found a method for suppressing the formation of low molecular weight compounds during the polymerization reaction in the above-mentioned interfacial polymerization method. That is,
In the present invention, phosgene is reacted with a mixed solution of a caustic aqueous solution of a dihydric phenol and an organic solvent while maintaining an oil-in-water dispersion type suspension to form a reaction solution of a polycarbonate oligomer. After inversion of the solution into a water-in-oil dispersion type emulsion and adding a polymerization catalyst to the emulsion, 10
After passing through the orifice hole at a speed of 0 cm / s or more,
It is a continuous process for producing an optical polycarbonate, characterized in that the polymerization reaction is completed by repeating the step of aging for 5 to 600 seconds once or more. Furthermore, as a preferred embodiment, in the above method, the terminal stopper is added to the emulsion prior to the addition of the polymerization catalyst.

The present inventors presume that the method of the present invention can improve the rate of polymerization reaction, so that the amount of catalyst can be reduced and, in turn, the production of low molecular weight compounds due to side reactions can be suppressed. According to the present invention, the obtained polycarbonate resin has a content of the monomer oligomer reduced to 0.2% by weight or less, and thus is useful as an optical material requiring high quality. In addition, heat resistance is adversely affected,
It was also found that the residual amount of terminal chloroformate groups in the polymer was also reduced.

The present invention will be described in detail below. The polycarbonate resin referred to in the present invention is obtained by reacting phosgene with an interfacial polymerization method, containing a dihydric phenol compound as a main component. Aromatic homo or copolycarbonate resins using bisphenols, further branched ones, ones having a long-chain alkyl group introduced at the end, and the like, have a viscosity average molecular weight of 130
Those in the range of 00 to 100,000 are applicable. Furthermore, as a terminal terminating agent or a comonomer, a polycarbonate resin having a double bond produced by reacting a compound having a carbon-carbon double bond is produced, and a polycarbonate resin having a graph reaction of styrene or the like, or a phenol to polystyrene or the like. Any of a hydroxyl group and a polycarbonate resin obtained by graft-polymerizing other reactive monomers can be applied. Among these, examples of the aromatic polycarbonate resin include a polycarbonate containing bisphenol A as a main raw material, and a polycarbonate copolymer obtained by using it in combination with, for example, bisphenol Z or tetrabromobisphenol A (TBA). Of these, branched products and products modified with long-chain alkyl at the end are preferable.

Preferred bisphenol compounds used in the method for producing the polycarbonate resin of the present invention are specifically bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether and bis (4-hydroxyphenyl). ) Sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1-bis (4-hydroxyphenyl)
Ethane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A; BPA), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane 2 (TBA), 2-bis (4- Hydroxyphenyl)
Butane, 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z; BPZ), 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4- Hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-
Hydroxy-3-chlorophenyl) propane, 2,2-
Bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, α, ω-bis [3- (O
Examples include -hydroxyphenyl) propyl] polydimethylsiloxane (PDS) and biphenol. You may use these in combination of 2 or more types. Among them, those selected from bisphenol A, bisphenol Z, TBA and PDS are preferable.

Examples of the terminal terminator (or molecular weight modifier) used in the present invention include compounds having a monovalent phenolic hydroxyl group.
In addition to t-butylphenol, tribromophenol, etc.,
Examples thereof include long-chain alkylphenols, aliphatic carboxylic acid chlorides, aliphatic carboxylic acids, aromatic carboxylic acids, aromatic acid chlorides, hydroxybenzoic acid alkyl esters and alkyl ether phenols. It may also be used as a terminal terminator having a reactive double bond, and examples of such a case include acrylic acid, vinyl acetic acid, 2-pentenoic acid, 3-pentenoic acid, 5-hexenoic acid, 9-undecenoic acid and the like. Unsaturated carboxylic acids; acid chlorides or chloroformates such as acrylic acid chloride, sorbic acid chloride, allyl alcohol chloroformate, isopropenylphenol chloroformate or hydroxystyrene chloroformate; isopropenylphenol, hydroxystyrene, hydroxy Examples thereof include phenols having an unsaturated group such as phenylmaleimide, hydroxybenzoic acid allyl ester, and hydroxybenzoic acid methylallyl ester. Of these, phenol and pt-butylphenol are preferable.

The amount of the terminator used is 2 as described above.
Usually, 1 to 25 relative to 1 mol of the phenolic compound.
It is used in the range of mol%, preferably 1.5 to 10 mol%. The terminal stopper can be added in the state of an organic solvent solution or an aqueous solution of caustic alkali, but if left in the state of an alkaline aqueous solution, it will turn red and affect the hue of the polycarbonate molded product. It is preferable to add it, and usually it is added as a 10 to 30% by weight solution.

The organic solvent used in the present invention includes dichloromethane, 1,2-dichloroethane, 1,1,2,2.
-Chlorinated hydrocarbons such as tetrachloroethane, chloroform, 1,1,1-trichloroethane, carbon tetrachloride, monochlorobenzene and dichlorobenzene; aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene;
An ether compound such as diethyl ether may be used, and two or more kinds of these organic solvents may be mixed and used. In addition, if desired, solvents other than the above, such as ethers, ketones, esters, and nitriles, which have an affinity for water may be used within the limit that the mixed solvent system is not completely compatible with water.

Further, the branching agent is used in an amount of 0.01 to 3 mol%, particularly 0.1 to 3% based on the above-mentioned dihydric phenol compound.
A branched polycarbonate can be used in combination within the range of 1.0 mol%. As a branching agent, phloroglucin, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3,4,6-dimethyl-2,
4,6-Tri (4-hydroxyphenyl) heptene-
2,1,3,5-tri (2-hydroxyphenyl) benzole, 1,1,1-tri (4-hydroxyphenyl)
Ethane, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, α, α ^' , α ^" -tri (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, etc. Exemplified polyhydroxy compounds, and 3,3-bis (4-hydroxyphenyl) oxindole (= isatin bisphenol), 5-chloroisatin bisphenol, 5,7-dichloroisatin bisphenol, 5-bromoisatin bisphenol Are exemplified.

In the present invention, a mixed solution of a caustic aqueous solution of a dihydric phenol and an organic solvent is made into an oil-in-water dispersion type suspension state by stirring means such as a stirring tank equipped with a stirrer, a tubular reactor and a static mixer. The polycarbonate oligomer is produced by reacting with phosgene while maintaining. The molar ratio of dihydric phenol and phosgene is usually in the range of 1: 1.02 to 1.35. If a water-in-oil dispersion type emulsion is formed during the phosgenation reaction, the decomposition rate of phosgene increases and side reactions are promoted, which is not preferable, so an oil-in-water dispersion suspension is formed during the phosgenation reaction. I will let you. As a means for forming an oil-in-water dispersion type suspension, a method of continuing stirring from the initial stage of phosgene introduction to the end of the phosgenation reaction is generally used. The polycarbonate oligomer thus obtained has a molecular weight of 2000 to 450 in terms of viscosity average molecular weight.
The range is 0. In the caustic aqueous solution at the end of the phosgenation reaction, unreacted dihydric phenol is 0.2-2.
0 w / v% remains.

Upon completion of the phosgenation reaction, additional caustic alkali and organic solvent are added to the mixed solution containing the polycarbonate oligomer, if necessary. At this time, if the reaction liquid is phase-inverted into a water-in-oil dispersion type emulsion, poor dispersion of the additional raw material occurs, which is not preferable, so when adding these additional raw materials, continue stirring or the like. Thus, it is necessary for the reaction solution to maintain an oil-in-water dispersion type suspension.

In the present invention, the terminal terminating agent may be added immediately after the completion of the phosgenation reaction, but it is preferable to add the necessary amount of the terminal terminating agent to the emulsion prior to the addition of the polymerization catalyst described below. The reduction rate is high, which is particularly preferable.

In the present invention, the thus obtained oil-in-water dispersion type reaction solution is phase-inverted into a water-in-oil dispersion type emulsion. By inverting the phase in the water-in-oil dispersion type emulsion, it is possible to widen the contact area of the water phase / organic phase, accelerate the polymerization reaction rate, and suppress the amount of the catalyst used. As a method of inverting the oil-in-water dispersion type reaction solution into a water-in-oil type emulsion, a simple stirring blade (paddle, propeller, turbine,
It is also possible to complete the polymerization reaction by increasing the rotation speed by using a chi-type wing). Further, as a device for obtaining a high degree of stirring state, there are a homogenizer, a high-speed stirrer such as a homomixer, a colloid mill, an orifice mixer, a flow jet mixer, an ultrasonic emulsifier, etc. It is particularly effective because it can obtain a different emulsion.

In the method of the present invention, a small amount of the emulsion is charged as a seed emulsion at the beginning of the operation, and the oil-in-water dispersion type reaction solution is continuously added to the seed emulsion while continuing stirring. It is preferable to use a method in which the phase is sequentially converted into a water-in-oil dispersion type emulsion by adding it to.

As a method of confirming the formation of the oil-in-water dispersion type solution and the water-in-oil dispersion type emulsion, a capacitance type or conductivity type monitor is used.

In the present invention, after adding the polymerization catalyst to the emulsion obtained by the above method, the mixed solution of the emulsion and the polymerization catalyst is added at 100 cm / s by using a device such as a press-fitting pump.
After passing through the orifice hole at the above speed, 5-60
The polymerization reaction is completed by repeating the step of aging for 0 seconds once or more. By this method, the polymerization reaction rate can be significantly improved.

Here, the passage speed of the orifice is 100
If it is less than cm / s, sufficient agitation and mixing are not carried out, resulting in poor catalyst dispersion and poor polymerization reaction. The flow velocity can be increased by narrowing the orifice diameter, but if the flow velocity exceeds the above range, the pressure loss at the orifice becomes too large, the power of the press-fitting pump becomes excessive, and the entire device must be pressure resistant. Therefore, the range of 100 to 2500 cm / s is usually preferable. After passing through the orifice, the emulsion is aged for 5 to 600 seconds for the purpose of promoting the polymerization reaction. The aging method is to allow the emulsion to stand or to pass through a pipe to increase the residence time. The effect is not improved even if the aging time is too long. Therefore, it is particularly preferable to perform the aging in the range of 10 to 300 seconds.

The number of repetitions of the step is related to the flow velocity of the liquid passing through the orifice. When the flow velocity is 2000 cm / s or more, the number of repetitions is 1 to 3 and the flow velocity is 1200.
In the case of ~ 2000 cm / s, the flow velocity is 8 about 2 to 5 times.
When the flow rate is less than 800 cm / s, it is preferable to perform the operation in the range of 3 to 10 times, and when the flow rate is less than 800 cm / s, the range of 5 to 30 times.

As the polymerization catalyst, a catalyst usually used in the interfacial polymerization reaction of polycarbonate can be used, but generally, a tertiary amine or a quaternary ammonium salt is selected. The catalyst is preferably dissolved in an organic solvent or water and added, and the concentration of the solution is adjusted to 0.2 to 15 v / v% before use.
If the concentration is lower than this range, the composition of the emulsion changes significantly, and the amount of low-molecular weight products increases, which is not preferable. On the other hand, if the concentration is higher than this range, poor dispersion in the reaction solution may occur, which is not preferable.

As a method of confirming that the molecular weight of the polymer at the completion of the polymerization reaction is within the target range, the fact that the viscosity average molecular weight and the viscosity of the emulsion have a positive correlation is used to prepare each composition. By grasping this relationship in advance for each and continuously measuring the viscosity of the emulsion,
A method of knowing the viscosity average molecular weight of the polycarbonate is preferable.

After the polymerization reaction is completed, the solvent solution is separated from the obtained polycarbonate polymerized resin liquid, and the catalyst is removed, neutralized, washed with water, concentrated, etc., and further subjected to a centrifugal separation method or microfiltration. , To obtain a purified polycarbonate resin solution. As a method for obtaining a solid substance from the polycarbonate resin solution, a known method can be used. For example, a method in which an organic solvent solution of polycarbonate is mixed with a poor solvent as needed and then added dropwise to warm water under stirring, or an organic solvent solution of polycarbonate is put into a kneader with a heating jacket, and granulated and dried. And the like are used.

[0028]

The present invention will be described in more detail with reference to the following examples, but the invention is not limited thereto as long as the scope of the present invention is not exceeded.

(1) Content of low molecular weight oligomer in polymer: 100 mg of polymer was dissolved in 20 ml of chloroform, and GPC (Column: Shode) manufactured by Waters Co.
x K803L x 2, detector: 490UV detector, 2
54 nm, AUFS 1.0), sample amount 100
The measurement was carried out at a flow rate of 1.0 μl / min and the solvent flow rate was 1.0 ml / min, and the content (wt%) of the monomer / oligomer in the polymer was determined from the peak area around the retention time of 19.25 minutes.

(2) Hue evaluation method: Each polymer was injection molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd .:
Neomat 350/120), resin temperature 320 ℃, mold temperature 80 ℃, holding pressure 1000kg / cm ² , 50mm × 60
mm, 3 mm thick molded pieces are continuously molded, and the molded pieces are color-measured with a color difference meter manufactured by Nippon Denshoku Co., Ltd., and the YI value (index indicating yellowness; the smaller the number, the better) I asked.

(3) Chlorine concentration derived from terminal chloroformate group: The polymer was dissolved in a dichloromethane solvent at a concentration of 0.05 to 5 g / L according to the remaining amount of the chloroformate group, and 4- (nitrobenzyl ) Pyridine 0.8 g / L
Is added so that the concentration becomes, and color is developed. The absorbance of the obtained colored solution at 440 nm was measured to be 0.2 to 20.
Using a factor obtained from the absorbance of a mol / L phenyl chloroformate standard solution, the concentration was converted into the chloroformate concentration, and further converted into the chlorine concentration.

Example 1 In a stirring tank having an internal volume of 50 L and equipped with an agitator-type stirrer (manufactured by Shimazaki Seisakusho Co., Ltd., triangular two-blades, inversion number 135 cpm), bisphenol A 63 kg / h, 8.8 w / w% water was added. An aqueous solution of sodium oxide (340 L / h) and hydrosulfite (HD) (270 g / h) were continuously fed, and the overflowing mixed liquid and methylene chloride 140 L / h.
Is continuously supplied to a phosgenation tank having an internal volume of 50 L in which an agitator-type stirrer is installed, and phosgene of 31 kg /
Phosgenation was carried out by feeding at h. During the phosgenation, the reaction solution maintained an oil-in-water dispersion type suspension.
In the reaction solution overflowing from the phosgenation tank, as a terminal stopper, a methylene chloride solution of pt-butylphenol (13.3 w / w%) 17.3 kg / h, methylene chloride 75 L / h, 8.8 w / A w% aqueous sodium hydroxide solution (50 L / h) was continuously added, and stirring was performed while maintaining the oil-in-water dispersion suspension in a stirring tank (internal volume: 50 L) equipped with a propeller impeller agitator.

The reaction liquid overflowing from the stirring tank was sent to an emulsion tank (internal volume: 50 L, equipped with an agitator-type stirrer) which was filled with methylene chloride at the start of the operation, to give a water-in-oil dispersion type emulsion. The phase has changed. After that, the water-in-oil dispersion type emulsified state was maintained in the emulsion tank. To the emulsion overflowing from the emulsion tank, 0.4 L / methylene chloride solution of triethylamine (10 v / v%) was used as a polymerization catalyst.
After adding in h, using a plunger pump to a polymerization apparatus, which has 15 orifices with a hole diameter of 14 mm at the inlet and 15 pipes with a diameter of 5 cm and a length of 100 cm are connected in series,
Feed rate of 640 L / h (Flow velocity at orifice hole 1
It was pressed in at a pressure of 15 cm / s and a residence time in each pipe of 11 seconds). The polymerized resin liquid overflowing from the polymerization equipment consists of an alkaline aqueous phase and an organic phase in which the polycarbonate resin is dissolved.
The phases were separated. The upper liquid was removed, the methylene chloride phase was neutralized with phosphoric acid, and then washed with pure water to obtain a purified resin liquid of polycarbonate. Put the resulting purified resin solution in the evaporation dish,
After drying at 140 ° C. for 4 hours, a dry solid was obtained. As a result of GPC measurement of the solid matter, the viscosity average molecular weight was 15600, and the content of the monomer oligomer in the polymer was 0.1.
7 wt%, chlorine concentration derived from terminal chloroformate group is 0.063 ppm, hue YI value of continuous plate is 0.9
It was 3.

Example 2 In Example 1, as a polymerization apparatus, a hole diameter of 14 m was provided at the inlet.
m with orifice, diameter 20 cm x length 330 cm
Polymerization device with 15 pipes connected in series (flow velocity of orifice hole is 115 cm / s, residence time in each pipe is 58).
Example 1 was repeated except that 3 seconds) was used. As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 15550, the content of the monomer oligomer in the polymer was 0.16 wt%, and the chlorine concentration derived from the terminal chloroformate group was 0.045 ppm, continuous. The hue YI value of the plate was 0.90.

Example 3 In Example 1, as a polymerization apparatus, a hole diameter of 3.2 was provided at the inlet.
Diameter 16 cm x length 300 with orifice holes of mm
cm was used in the same manner as in Example 1 except that a polymerization device in which two pipes were connected in series (flow rate at the orifice hole portion was 2210 cm / s, residence time in each pipe was 340 seconds),
I repeated. As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 15,300, the content of the monomer oligomer in the polymer was 0.15 wt%, and the chlorine concentration derived from the terminal chloroformate group was 0.048 ppm, continuous. The hue YI value of the plate was 0.88.

Example 4 In Example 1, as a polymerization apparatus, a hole diameter was 5 mm at the inlet.
10cm diameter x 300cm length
3 pipes (flow velocity at the orifice hole is 905 cm /
s, residence time in each pipe 133 seconds), and hole diameter 10
Diameter 10 cm x length 300 cm with mm orifice
There are 13 pipes (the flow velocity at the orifice hole is 226 cm /
s, residence time in each pipe was 133 seconds), a total of 16 units were connected in series, and the same procedure as in Example 1 was repeated except that a polymerization apparatus was used. As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 15,600, the content of the monomer oligomer in the polymer was 0.14 wt%, the chlorine concentration derived from the terminal chloroformate group was 0.052 ppm, and continuous. The hue YI value of the plate was 0.89.

Comparative Example 1 63 kg / h of bisphenol A and 8.0 w / w% of water was placed in a stirring tank having an internal volume of 50 L, in which an agitator-type stirrer (manufactured by Shimazaki Seisakusho Co., Ltd., triangular 2-blade, inversion number 135 cpm) was installed. An aqueous solution of sodium oxide (340 L / h) and hydrosulfite (HD) (270 g / h) were continuously fed, and the overflowing mixed liquid and methylene chloride 140 L / h.
Is continuously supplied to a phosgenation tank having an internal volume of 50 L in which an agitator-type stirrer is installed, and phosgene of 31 kg /
Phosgenation was carried out by continuously feeding at h. When the stirring was temporarily stopped during the phosgenation, the mixture was allowed to stand for 5 minutes for separation and then stirred again, the reaction liquid in the phosgenation tank was phase-inverted into a water-in-oil dispersion type emulsion. I was holding.

In the water-in-oil type reaction solution overflowing from the phosgenation tank, a methylene chloride solution of pt-butylphenol (13.3 w / w%) was added as a terminal stopper.
7.3 kg / h, methylene chloride 75 L / h, 8.
When 8 W / w% aqueous sodium hydroxide solution (50 L / h) was continuously added and stirred in an emulsion tank (internal volume: 50 L) equipped with a propeller impeller agitator, a water-in-oil dispersion type emulsified state was exhibited. . After that, the liquid in the emulsification tank maintained the water-in-oil dispersion type emulsified state. A methylene chloride solution of triethylamine (10 v / v%) was added as a polymerization catalyst at 0.4 L / h to the emulsion overflowing from the emulsion tank, and then an orifice hole having a diameter of 14 mm was provided at the inlet. 5
cm × 100 cm length of 15 pipes connected in series to the polymerization apparatus using a plunger pump at 640 L /
Feed rate of h (Flow velocity of orifice hole is 115 cm /
s, residence time in each pipe was 11 seconds). The polymerized resin liquid overflowing from the polymerizer was not separated into two phases, an aqueous phase and an organic phase. The polymerized resin solution was neutralized with phosphoric acid and washed with pure water to obtain a purified resin solution of polycarbonate. The obtained purified resin solution was placed in an evaporation dish and dried at 140 ° C. for 4 hours to obtain a dry solid. As a result of GPC measurement of the solid matter, the viscosity average molecular weight was 12,400, the content of the monomer oligomer in the polymer was 8.22 wt%, the chlorine concentration derived from the terminal chloroformate group was 12.5 ppm, and the hue of the continuous plate was measured. The YI value was 2.88.

Comparative Example 2 The procedure of Example 1 was repeated except that after completion of the phosgenation reaction, the water-in-oil-dispersed emulsion was not phase-inverted, but was directly injected into the polymerization apparatus. It was As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 8800.
And the content of monomeric oligomer in the polymer is 1
2.5 wt%, the chlorine concentration derived from the terminal chloroformate group was 100 ppm or more (not measurable), and the hue YI value of the continuous plate was 3.7.

Comparative Example 3 In Example 1, as a polymerization device, a hole diameter of 16 m was provided at the inlet.
m orifice hole, diameter 5 cm x length 100 cm
Was repeated in the same manner as in Example 1 except that a polymerization device (flow rate of orifice hole portion was 88 cm / s, residence time in each pipe was 11 seconds) in which 15 pipes were connected in series was used. As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 1
It was 4600, the content of the monomer oligomer in the polymer was 1.05 wt%, the chlorine concentration derived from the terminal chloroformate group was 2.2 ppm, and the hue YI value of the continuous plate was 1.9.

Example 5 In Example 1, except that the supply place of the methylene chloride solution of pt-butylphenol as the terminal stopper was changed to the emulsion overflowing from the emulsion tank of Example 1. Repeated as in Example 1. As a result of GPC measurement of the obtained solid, the viscosity average molecular weight was 15300.
And the content of the monomer oligomer in the polymer is 0.
09 wt%, chlorine concentration derived from terminal chloroformate group is 0.057 ppm, hue YI value of continuous plate is 0.9
It was 1.

[0042]

According to the production method of the present invention, it is possible to suppress the formation of a monomer oligomer during a polymerization reaction, which was difficult in the conventional production method of a polycarbonate resin by an interfacial polymerization method. Further, the residual amount of the terminal chloroformate group in the polymer, which adversely affects the heat resistance, can be reduced, so that it is particularly useful as a raw material for optical discs and compact discs that require high quality under high temperature and high humidity. It is possible to provide a continuous method for producing an optical polycarbonate resin.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-100686 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 64/00-64/42

Claims (2)

(57) [Claims] 1. A phosgene is reacted with a mixed solution of a caustic aqueous solution of a dihydric phenol and an organic solvent while maintaining an oil-in-water dispersion type suspension to form a reaction solution of a polycarbonate oligomer. One step of inverting the reaction solution into a water-in-oil dispersion type emulsion, adding a polymerization catalyst to the emulsion, passing through the orifice holes at a speed of 100 cm / s or more, and then aging for 5 to 600 seconds once. A continuous process for producing an optical polycarbonate, characterized by completing the polymerization reaction by repeating the above. 2. The method according to claim 1, wherein the terminal stopper is added to the emulsion prior to the addition of the polymerization catalyst.