WO2008065776A1

WO2008065776A1 - Process for industrial production of high-quality aromatic polycarbonate

Info

Publication number: WO2008065776A1
Application number: PCT/JP2007/064431
Authority: WO
Inventors: Shinsuke Fukuoka; Hironori Miyaji; Hiroshi Hachiya
Original assignee: Asahi Kasei Chemicals Corporation
Priority date: 2006-11-27
Filing date: 2007-07-23
Publication date: 2008-06-05
Also published as: JP5320071B2; JPWO2008065776A1; TW200829621A

Abstract

The invention aims at providing a specific process by which a high-quality and high-performance aromatic polycarbonate which is little discolored and is excellent in mechanical properties can be stably produced from a cyclic carbonate and an aromatic dihydroxyl compound industrially on a large scale (e.g., in an amount of at least one ton per hour) over a long period (e.g., over a period of 1000 hours or longer, preferably 3000 hours or longer, still preferably 5000 hours or longer). The aim can be attained by a process for the production of an aromatic polycarbonate from a cyclic carbonate and an aromatic dihydroxyl compound which comprises the step (I) of preparing a dialkyl carbonate and a diol by using a reaction-distillation column having specific structure, the step (II) of preparing a diaryl carbonate by using two reaction-distillation columns having specific structure, the step (III) of purifying the diaryl carbonate to obtain a high-purity diaryl carbonate, the step (IV) of converting a molten prepolymer prepared from an aromatic dihydroxyl compound and the high-purity diaryl carbonate into an aromatic polycarbonate by using a guide-contact flowing down type polymerizer having specific structure, and the step (V) recycling an aromatic monohydroxyl compound formed as by-product to the step (II).

Description

Specification

Industrial production of high-quality aromatic polycarbonate.

Technical field

[0001] The present invention relates to an industrial process for producing an aromatic polycarbonate. More specifically, the present invention industrially and stably produces a high-quality, high-performance aromatic polycarbonate that is free of coloring and has excellent mechanical properties from a cyclic carbonate and an aromatic dihydroxy compound in a large amount for a long period of time. Regarding the method.

Background art

Aromatic polycarbonate is widely used in many fields as engineering plastics having excellent heat resistance, impact resistance and transparency. Various researches have been conducted on the production method of this aromatic polycarbonate, and among them, aromatic dihydroxy compounds such as 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) are included. The interfacial polycondensation process between phosgene and phosgene has been industrialized. However, in this interfacial polycondensation method, toxic phosgene must be used, methylene chloride, which is harmful to health and the environment, must be used in a large amount of more than 10 times per polycarbonate as a polymerization solvent, The equipment is corroded by by-product hydrogen chloride, sodium chloride, and chlorine-containing compounds such as methylene chloride, and it is difficult to separate residual chlorine impurities such as sodium chloride and methylene chloride, which adversely affect the physical properties of the polymer. There are many issues such as the need to treat a large amount of process wastewater containing methylene chloride and unreacted bisphenol A.

[0003] On the other hand, as a method for producing an aromatic polycarbonate from an aromatic dihydroxy compound and diaryl carbonate, for example, bisphenol A and diphenyl carbonate are transesterified in a molten state, and by-product phenol is obtained. Melting methods that polymerize while being extracted have been known for a long time. This transesterification reaction is an equilibrium reaction, and the force, but its equilibrium constant is small, so that the polymerization does not proceed unless phenol is efficiently extracted from the surface of the melt. Unlike the interfacial polycondensation method, the melting method has the advantage of not using a solvent. On the other hand, when the polymerization proceeds to some extent, the viscosity of the polymer rises rapidly, resulting in by-product phenol. There is an essential problem based on the aromatic polycarbonate itself that it is difficult to efficiently remove the catalyst from the system and the degree of polymerization cannot be substantially increased. In other words, in the case of aromatic polycarbonate, unlike the case of melt polycondensation of other condensation polymers such as polyamide and polyester, even if the low molecular weight state, for example, the degree of polymerization (n) is about 15-20, Its melt viscosity becomes extremely high, and surface renewal becomes very difficult with normal stirring. Further, phenol is not extracted from the polymer surface substantially, and a polymer having a degree of polymerization necessary for a product (n = 35 to 65) cannot be produced. This is well known in the art.

[0004] Various polymerizers are known as a polymerizer for producing an aromatic polycarbonate by a melting method. A method using a vertical stirring tank type polymerizer equipped with a stirrer is generally well known. However, the vertical stirred tank type polymerizer has the advantage of high volumetric efficiency and small size on a small scale, and can proceed with polymerization efficiently, but on an industrial scale, as described above. As the polymerization proceeds, it is difficult to efficiently extract phenol as a by-product out of the system, and the polymerization rate is extremely low. Furthermore, a large-scale vertical stirred tank type polymerization apparatus usually has a larger liquid volume ratio to the evaporation area than a small scale, and the so-called liquid depth is large. For this reason, even if the degree of vacuum is increased in order to increase the degree of polymerization, the lower part of the stirring tank has a liquid depth, so that the polymerization is performed at a higher pressure corresponding to the liquid depth than the upper space part. Therefore, it becomes difficult to efficiently extract phenol and the like. Therefore, a large-scale vertical stirring tank type polymerization apparatus cannot be used only when producing a prepolymer. In order to achieve the required degree of polymerization, a polymerizer for further proceeding the polycondensation reaction from this prepolymer is essential.

[0005] In order to solve this problem, various contrivances have been made to efficiently extract phenol and the like from a polymer having a high viscosity state. Most of these devices are related to improvements in mechanical stirring. For example, a method using a screw-type polymerizer having a vent (see Patent Document 1), a method using a combined twin-screw extruder ( Patent Document 2)), and a method using a thin film evaporation reactor such as a screw evaporator or a centrifugal thin film evaporator (see Patent Document 3) is described. Horizontal biaxial stirring polymerization A method of using a combination of vessels (see Patent Document 4) is specifically disclosed. All of these methods are based on the mechanical agitation, and have their own limitations, and have not yet solved this problem. In other words, since there is a limit to the mechanical agitation itself that can cope with the ultra-high melt viscosity, various problems relating to the ultra-high melt viscosity of the aromatic polycarbonate remain unsolvable. These methods can be solved by raising the temperature and lowering the melt viscosity as much as possible!

[0006] That is, it is the power of these methods to perform polymerization while renewing the surface of the molten prepolymer with mechanical stirring under a high temperature and high vacuum near 300 ° C. Even at this temperature, the melt viscosity is still very high. For this reason, the degree of surface renewal cannot be increased. Therefore, the degree of polymerization of polycarbonate that can be produced by these methods is limited, and it is difficult to produce high molecular weight grade products. Furthermore, since these methods react at a high temperature close to 300 ° C, the resulting polymer is likely to be colored or deteriorated in physical properties, and in addition, the polymer may be leaked due to leakage of air or foreign matter from the vacuum seal of the stirrer. There are still many problems to be solved in order to stably produce high-quality polycarbonate for a long period of time, such as coloration and deterioration of physical properties.

[0007] The inventors of the present invention have used a guide contact flow type polymerization apparatus in which the molten polymer is polymerized while dropping by its own weight along a guide such as a wire without mechanical stirring. We found out that these problems could be solved completely by developing, and filed earlier. (For example, see Patent Documents 5 to 12). However, these methods include disclosure of specific methods related to industrial production methods that can produce 1 ton or more of aromatic polycarbonate per hour. There was no suggestion.

[0008] Furthermore, in order to produce an aromatic polycarbonate by an ester exchange reaction on an industrial scale, it is necessary to obtain a large amount of high-purity diaryl carbonate on an industrial scale. Aromatic dihydroxy compounds, such as high-purity bisphenol A, are manufactured in large quantities industrially and are easy to obtain.To obtain high-purity diaryl carbonate in large quantities on an industrial scale, Impossible. It is therefore necessary to produce this.

[0009] As a method for producing diaryl carbonate, an aromatic monohydroxy compound and phosgene are used. Reaction methods have been known for a long time, and various studies have been made recently. However, in this method, in addition to the problem of using phosgene, the diaryl carbonate produced by this method contains chlorine-based impurities that are difficult to separate, and cannot be used as a raw material for aromatic polycarbonate as it is. This is because this chlorine-based impurity significantly inhibits the polymerization reaction of the transesterification aromatic polycarbonate carried out in the presence of a very small amount of a basic catalyst. Can't progress. Therefore, in order to use as a raw material for transesterification aromatic polycarbonate, sufficient washing with dilute alkaline aqueous solution and warm water, oil-water separation, and distillation, etc., are required. · There are many problems in implementing this method on an industrial scale that is economically reasonable, such as a decrease in yield due to hydrolysis loss and distillation loss in the purification process.

[0010] On the other hand, a method for producing an aromatic carbonate by a transesterification reaction between a dialkyl carbonate and an aromatic monohydroxy compound is also known. However, these ester exchange reactions are all equilibrium reactions, and the reaction rate is slow in addition to the fact that the equilibrium is extremely biased toward the original system. It was very difficult to industrially produce large quantities of aromatic carbonates.

[0011] Several proposals have been made to improve this, most of which relates to the development of catalysts to increase reaction rates. Many metal compounds have been proposed as catalysts for this type of transesterification reaction. However, the catalyst development alone cannot solve the problem of unsatisfactory IJ equilibrium. There are challenges.

[0012] On the other hand, attempts have been made to improve the yield of aromatic carbonates by devising the reaction system to shift the equilibrium to the production system as much as possible. For example, in the reaction of dimethyl carbonate and phenol, by-product methanol is distilled off together with the azeotropic agent by azeotropic distillation (see Patent Document 13), and by-product methanol is adsorbed by molecular sieves. And a method of removing it (see Patent Document 14). In addition, the apparatus equipped with a distillation tower at the top of the reactor performs distillation separation of unreacted raw materials that simultaneously evaporate while separating alcohols by-produced from the reaction from the reaction mixture. A method has also been proposed (see Patent Document 15).

However, these reaction systems are basically a batch system force and a switching system.

This is because the improvement of the reaction rate due to the development of the catalyst has a limit for these transesterification reactions, and the reaction rate is slow, so that the batch method was considered preferable to the continuous method. Among these, a continuous stirred tank reactor (CSTR) system with a distillation column at the top of the reactor has also been proposed as a continuous system! There is a problem that the gas-liquid interface is small relative to the liquid volume, so the reaction rate cannot be increased! Therefore, it is difficult to achieve the objective of stably producing a large amount of aromatic carbonate continuously by these methods for a long period of time, and there are still many in order to achieve economically reasonable industrial implementation. Issues to be solved remain.

[0014] The inventors of the present invention continuously supply dialkyl carbonate and aromatic hydroxy compound to a multistage distillation column, continuously react in the column in the presence of a catalyst, and contain a by-product alcohol. The boiling point component is continuously extracted by distillation, and the component containing the generated alkylaryl carbonate is extracted from the lower part of the column (see Patent Document 16). The alkylaryl carbonate is continuously supplied to the multistage distillation column. The reaction is continuously carried out in the column in the presence of a catalyst, and low-boiling components including dialkyl carbonate as a by-product are continuously extracted by distillation, and the generated components including diaryl carbonate are extracted from the bottom of the column. Reactive distillation (see Patent Document 17), these reactions are carried out using two continuous multistage distillation towers, and by-product dialkyl carbonate is effectively used. Reactive distillation method (see Patent Document 18), which continuously produces diaryl carbonate while being recycled, continuously supplies dialkyl carbonate and aromatic hydroxy compound to the multistage distillation column, and flows down in the column. The liquid to be discharged is extracted from a side outlet provided in the middle stage and / or the lowermost stage of the distillation tower, introduced into a reactor provided outside the distillation tower and reacted, and then from the stage having the outlet. These esters, such as reactive distillation (see Patent Document 19), in which the reaction is carried out in both the reactor and the distillation column by being introduced into the circulation inlet provided in the upper stage. We have developed a reactive distillation method in which the exchange reaction is carried out in a continuous multistage distillation column at the same time and the distillation separation, and we disclosed for the first time in the world that the reactive distillation method is useful for these transesterification reactions. [0015] These reactive distillation methods proposed by the present inventors are the first to make it possible to produce aromatic carbonates efficiently and continuously, and then based on these disclosures, There has been proposed a method for producing diaryl force-bonate from dialkyl carbonate using two continuous multi-stage distillation columns (see Patent Documents 20 to 26).

[0016] Further, the applicant of the present invention has disclosed a high boiling point substance containing a catalyst component as an active substance as a method for stably producing a high-purity aromatic carbonate for a long time without requiring a large amount of catalyst in a reactive distillation system. (See Patent Document 27), and the polyvalent aromatic hydroxy compound in the reaction system is kept at a mass ratio of 2.0 or less with respect to the catalyst metal. (See Patent Document 28). Furthermore, the present inventors use 70 to 99% by mass of phenol by-produced in the polymerization step as a raw material to produce diphenyl carbonate by a reactive distillation method and use this as a polymerization raw material for aromatic polycarbonate. Was also proposed (see Patent Document 29).

[0017] However, all the prior literatures proposing the production of aromatic carbonates by these reactive distillation methods include specific examples that enable mass production on an industrial scale (for example, 1 ton per hour). There is no disclosure of methods or devices, nor is there any description suggesting them. For example, the height (H and H: cm) and diameter (D and D) of two reactive distillation columns disclosed to produce mainly diphenyl carbonate (DPC) from dimethyl carbonate and phenol.

1 2 1 and D: cm), the number of plates (n and n) and the amount of reaction raw material introduced (Q and Q: kg / hr)

2 1 2 1 2

Table 1 shows the descriptions.

[0018] [Table 1]

Hi Di Π1 Qi H ₂ D ₂ Π2 Q ₂

600 25 20 66 600 25 20 23 18

350 2.8 ― 0.2 305 5 ~ 10 15+ 0.6 21

Filling

500 5 50 0.6 400 8 50 0.6 22

100 4-1.4 200 4-0.8 23

300 5 40 1.5-5 25 0.7 24

1200 20 40 86 600 25 20 31 27

28

600 one 20 66 600 one 20 22 29 That is, the largest of the two continuous multistage distillation columns used for carrying out this reaction by the reactive distillation method is the one disclosed by the present applicant in Patent Documents 27 and 28. Thus, the maximum value of each condition in the continuous multistage distillation column disclosed for this reaction is H = 1200 cm, H = 600 cm, D = 20 cm, D = 25 cm, n = n = 50 (under this condition

1 2 1 2 1 2

Patent Document 22), Q = 86 kg / hr, Q = 31 kg / hr, and diphenyl carbon

1 2

The production rate of the cart was only about 6.7 kg / hr, which was not strong on an industrial scale.

[0020] The dialkyl carbonate used in the step (II) of the present invention needs to be produced on an industrial scale and further does not contain a halogen. The only method in which dialkyl carbonate is industrially produced in large quantities as a raw material for aromatic polycarbonate is the oxidative carbonylation method in which methanol is reacted with carbon monoxide and oxygen to produce dimethyl carbonate and water. Is due to. However, this oxidative carbonylation method (see Patent Document 30) requires a reaction in a slurry state using a large amount of CuCl-HCl as a catalyst, and the reaction system and separation / purification system are extremely corrosive. The problem is. Moreover, since carbon monoxide is easily oxidized to carbon dioxide by this method, the problem is that the selectivity based on carbon monoxide is as low as about 80%.

[0021] On the other hand, several proposals have been made on the process power for producing dialkyl carbonates and diols from the reaction of cyclic carbonates and aliphatic monohydric alcohols. This reaction is a preferred method because dialkyl carbonate can be produced without using halogen. Four methods have been proposed for this reaction. These four reaction methods are used in the most typical reaction example, a method for producing dimethyl carbonate and ethylene glycol from ethylene carbonate and methanol. These are (1) a complete batch reaction method. (2) Batch reaction method using a reaction kettle with a distillation column at the top, (3) Liquid flow reaction method using a tubular reactor, (4) Reaction distillation method disclosed by the present inventors for the first time (Patent Literature) 3; see! -39.). However, each of these methods has the following problems.

That is, in the cases of (1) and (3), since the upper limit of the reaction rate of the cyclic carbonate is determined by the charged composition and temperature, the reaction cannot be completed completely and the reaction rate is low. In the case of (2), in order to increase the reaction rate of the cyclic carbonate, The carbonate must be distilled off using a very large amount of an aliphatic monohydric alcohol, requiring a long reaction time. In the case of (4), the reaction can proceed at a higher reaction rate than in (1), (2), and (3). However, the method (4) that has been proposed so far is a method for producing a small amount of dialkyl carbonate and diol or a short-term production method, and is stable for a long time on an industrial scale. It was not about manufacturing. That is, the object is to stably produce dialkyl carbonate in a large amount continuously (for example, 2 tons or more per hour) for a long period of time (for example, 1000 hours or more, preferably 3000 hours or more, more preferably 5000 hours or more). It was not something to achieve.

[0023] For example, the height (H: cm), diameter (D) of the reactive distillation column in the examples disclosed for producing dimethyl carbonate (DMC) and ethylene glycol (EG) from ethylene carbonate and methanol. Table 2 shows the maximum values for (cm), number of plates (n), dimethyl carbonate production P (kg / hr), and continuous production time T (hr).

[0024] [Table 2]

(Note 1) Older show distillation column.

(Note 2) There is no description specifying the distillation column.

(Note 3) The description specifying the distillation column is only the number of plates.

(Note 4) There is no description of production volume.

(Note 5) There is no description of long-term stable production.

[0025] It should be noted that Patent Document 38 (paragraph 0060) states that "this embodiment is preferable as shown in FIG. 1 above". The process flow is the same as that of the embodiment, and the purpose is to operate a commercial scale apparatus for producing dimethyl carbonate and ethylene glycol by transesterification by a catalytic conversion reaction of ethylene carbonate and methanol. It should be noted that the numerical values described below in this embodiment are sufficiently applicable to the operation of an actual apparatus. As an example, it is described that 3 750 kg / hr of dimethyl carbonate was specifically produced. Since this scale described in the examples corresponds to an annual output of 30,000 tons or more, at the time of filing of Patent Document 38 (April 9, 2002), the world's largest large-scale commercial plant was operated by this method. It has been implemented. However, there is no such fact at all. Further, in the example of Patent Document 38, the production amount of dimethyl carbonate is the same as the theoretically calculated value, the yield of ethylene glycol is about 85.6%, and the selectivity is about 88. It is 4% and it is difficult to say that high yield and high selectivity are achieved. The low selectivity indicates that this method has a fatal defect as an industrial production method. (Note that Patent Document 38 was deemed to be dismissed by an unexamined request on July 26, 2005.) [0026] The reactive distillation method uses a composition change caused by a reaction in a distillation column and a composition caused by distillation. It is often difficult to continue stable operation over a long period of time because of the large number of fluctuation factors such as changes in temperature and pressure changes in the tower, especially when dealing with large quantities. Increase. It is necessary to devise a reactive distillation device in order to continue high-volume production of dialkyl carbonates and diols by reactive distillation while maintaining high yield and high selectivity for a long period of time. . However, the description of long-term continuous stable production in the reactive distillation method proposed so far was only 400 hours of Patent Document 31.

Patent Document 1: Japanese Patent Publication No. 50-19600 (British Patent No. 1007302)

Patent Document 2: Japanese Patent Publication No. 52-36159

Patent Document 3: Japanese Patent Publication No. 53-5718 (US Pat. No. 3,888,826) Patent Document 4: Japanese Patent Laid-Open No. 2-153923

Patent Document 5: JP-A-8-225641

Patent Document 6: JP-A-8-225643

Patent Document 7: JP-A-8-325373 Patent Document 8: WO 97-22650

Patent Document 9: Japanese Patent Laid-Open No. 10-81741

Patent Document 10: JP-A-10-298279

Patent Document l l: WO 99/36457

Patent Document 12: WO 99/64492

Patent Document 13: JP-A-54-48732 (West German Patent Publication No. 736063, US Pat. No. 4,252,737)

Patent Document 14: Japanese Patent Laid-Open No. 58-185536 (US Pat. No. 410464) Patent Document 15: Japanese Patent Laid-Open No. 56-123948 (US Pat. No. 4,182,726) Patent Document 16: Japanese Patent Laid-Open No. 3- No.291257

Patent Document 17: Japanese Patent Laid-Open No. 4 9358

Patent Document 18: Japanese Patent Application Laid-Open No. 4-211038 (WO 91/09832 Publication, European Patent 046 1274, US Patent 5210268)

Patent Document 19: JP-A-4 235951

Patent Document 20: Japanese Patent Laid-Open No. 6-157424 (European Patent 0582931 Specification, US Patent ϋ5334742 ^ | · „»)

Patent Document 21: Japanese Patent Laid-Open No. 6-184058 (European Patent 0582930, US Patent 5344954)

Patent Document 22: JP-A-9 40616

Patent Document 23: JP-A-9 59225

Patent Document 24: JP-A-9 176094

Patent document 25: WO 00/18720 (US Pat. No. 6093842)

Patent Document 26: JP 2001-64235 A

Patent Document 27: WO 97/11049 (European Patent No. 0855384, US Patent No. 5 872275 Uzuki Itoda)

Patent Document 28: Japanese Patent Laid-Open No. 11 92429 (European Patent No. 1016648, US Patent H6262210 ^ "„ »)

Patent Document 29: JP-A-9 255772 (European Patent 0892001 Specification, US Patent) ϋ5747609 ^ | · „»)

Patent Document 30: WO 03/016257

Patent Document 31: Japanese Patent Laid-Open No. 4 198141

Patent Document 32: JP-A-9 194435

Patent Document 33: WO99 / 64382 (European Patent No. 1086940, US Patent H6346638 ^ "„ »)

Patent Document 34: WO00 / 51954 (European Patent No. 1174406, US Patent H6479689 ^ "„ »)

Patent Document 35: Japanese Patent Laid-Open No. 5-213830 (European Patent No. 0530615, US Patent No. 5231212)

Patent Document 36: Japanese Patent Laid-Open No. 6-9507 (European Patent No. 0569812, US Patent No. 5359118)

Patent Document 37: Japanese Patent Laid-Open No. 2003-119168 (WO03 / 006418)

Patent Document 38: Japanese Patent Laid-Open No. 2003-300936

Patent Document 39: Japanese Patent Laid-Open No. 2003-342209

Disclosure of the invention

Problems to be solved by the invention

[0028] The problem to be solved by the present invention is that a large amount of high-quality, high-performance aromatic polycarbonate having no mechanical coloring and excellent mechanical properties from a cyclic carbonate and an aromatic dihydroxy compound (for example, a large amount (for example, It is to provide a specific method capable of stable production over a long period (for example, 1000 hours or more, preferably 3000 hours or more, more preferably 5000 hours or more) over 1 ton per hour.

Means for solving the problem

[0029] The inventors of the present invention have arrived at the present invention as a result of repeated studies to find out a specific method capable of achieving the above-mentioned problems.

[0030] That is, in the first aspect of the present invention,

1. An industrial production method for continuously producing high-quality aromatic polycarbonate from a cyclic carbonate and an aromatic dihydroxy compound, (I) Cyclic carbonate and aliphatic monohydric alcohol are continuously fed into a continuous multistage distillation column T in which a catalyst exists, and reaction and distillation are simultaneously performed in the column to produce dialkyl power.

0

Dialkyl carbonate and diols are obtained by a reactive distillation system in which a low-boiling reaction mixture containing bonates is continuously withdrawn in the form of gas from the top of the column and a high-boiling reaction mixture containing diols is continuously withdrawn in the form of liquid from the bottom of the column. Step (I) for continuously producing

(II) The dialkyl carbonate and the aromatic monohydroxy compound are used as raw materials, and this raw material is continuously fed into a first continuous multistage distillation column in which a catalyst exists, and the reaction and distillation are simultaneously performed in the first column. The first column low-boiling point reaction mixture containing the resulting alcohols is continuously withdrawn from the upper portion of the first column in the form of a gas, and the first column high-boiling point reaction mixture containing the generated alkylaryl carbonates is removed from the first column. The liquid is continuously withdrawn from the bottom of the first column, and the high-boiling point reaction mixture of the first column is continuously fed into the second continuous multi-stage distillation column in which the catalyst exists, and the reaction and distillation are simultaneously performed in the second column. The second tower low-boiling point reaction mixture containing dialkyl carbonates to be produced is continuously withdrawn in the form of a gas from the upper part of the second tower, and the second tower high-boiling point reaction mixture containing diaryl carbonates to be produced is removed from the second tower. Liquid and continuous from the bottom On the other hand, continuously supplying diaryl carbonate by continuously feeding the second column low boiling point reaction mixture containing dialkyl carbonates into the first continuous multi-stage distillation column, (II),

(III) purification step (III) for purifying the diaryl carbonate to obtain high purity diaryl carbonate;

(IV) The aromatic dihydroxy compound and the high-purity diaryl carbonate are reacted to produce an aromatic polycarbonate molten polymer, and the molten polymer is allowed to flow along the surface of the guide. A step (IV) of producing an aromatic polycarbonate using a guide contact flow type polymerization reactor for polymerizing a prepolymer; and

(V) Aromatic monohydroxy compound recycling step (V) in which the aromatic monohydroxy compound by-produced in step (IV) is circulated to the diaryl carbonate production step (II);

Including

(a) The continuous multi-stage distillation column has a cylindrical body having a T force S, a length L (cm), and an inner diameter D (cm),

0 0 0

It has an internal structure with n stages inside, and is at or near the top of the tower A gas outlet with an inner diameter d (cm) at the top of the tower, inside the bottom of the tower or near the bottom of the tower

01

Liquid outlet with diameter d (cm), below the gas outlet, at the top of the tower and / or

02

Has one or more first inlets in the middle part and one or more second inlets above the liquid outlet and in the middle part and / or lower part of the column. , D, L / D

0 0 0

, N, D / d, D / d ί satisfy formulas (1) to (6),

0 01 0 02

2100 <L ≤ 8000 (1)

0

180 <D ≤ 2000 (2)

0

4 <L / Ε) ≤ 40 (3)

0 0

10 <η ≤ 120 (4)

0

3 <D / ά ≤ 20 Equation (5)

0 01

5 <D / ά ≤ 30 (6)

(b) The first continuous multi-stage distillation column has a cylindrical body having a length L (cm) and an inner diameter D (cm), and has an internal structure having an internal number n of stages. At the top of the tower or near the top of the tower is a gas outlet with an inner diameter d (cm), at the bottom of the tower or near the bottom of the tower.

11

A liquid outlet with an inner diameter d (cm), below the gas outlet and above the tower and / or

12

Or one or more third inlets in the middle part and one or more fourth inlets above the liquid outlet and in the middle part and / or lower part of the tower, , D, L / D, n, D / d, D / d force, respectively satisfying the formulas (7) to (; 12),

1500 <L <8000 (7)

1

100 <D <2000 (8)

1

2 <L / '≤ 40 (9)

1 1

20 <n <120 Formula (10)

1

5 <D, Zd ≤ 30 (11)

1 11

3 <D, Zd ≤ 20 (12)

1 12

(c) The second continuous multi-stage distillation column has a cylindrical body having a length L (cm) and an inner diameter D (cm).

twenty two

It has an internal structure with n stages inside, and the top of the tower or near it

2

A gas outlet with an inner diameter d (cm) at the top of the tower, at the bottom of the tower or near the bottom of the tower

twenty one

A liquid outlet with an inner diameter d (cm), below the gas outlet and above the tower and / or Or one or more fifth inlets in the middle, and one or more sixth inlets above the liquid outlet and in the middle and / or lower part of the column, , D, L /

2 2 2

D, n, D / d, D / d force satisfy the equations (13) to (18),

2 2 2 21 2 22

1500 ≤ L ≤ 8000 formula (13)

2

100 ≤ D ≤ 2000 (14)

2

2 ≤ L / D ≤ 40 Equation (15)

twenty two

10 ≤ n ≤ 80 Equation (16)

2

2 ≤ D / d ≤ 15 Equation (17)

2 21

5 ≤ D / d ≤ 30 Equation (18)

2 22

(d) the guide contact flow type polymerizer,

(1) Molten prepolymer receiving port, perforated plate, a molten prepolymer feed zone for feeding the molten prepolymer to the guide of the polymerization reaction zone through the perforated plate, the perforated plate, the side casing, and the tapered bottom casing A polymerization reaction zone provided with a plurality of guides extending downward from the perforated plate in the enclosed space, a vacuum vent port provided in the polymerization reaction zone, and an aromatic polymer provided at the bottom of the tapered bottom casing A power-bonate discharge port, and an aromatic polycarbonate discharge pump connected to the discharge port,

(2) The internal cross sectional area A (m ² ) in the horizontal plane of the side casing of the polymerization reaction zone satisfies the formula (19),

0. 7 ≤ A ≤ 300 Equation (19)

(3) The ratio of the A (m ² ) and the internal cross-sectional area B (m ² ) in the horizontal plane of the aromatic polycarbonate outlet satisfies the formula (20),

20 ≤ A / B ≤ 1000 formula (20)

(4) The tapered bottom casing constituting the bottom of the polymerization reaction zone is connected to the upper side casing at an angle C degree inside, and the angle C degree satisfies the formula (21). To do,

120 ≤ C ≤ 165 Equation (21)

(5) The length h of the guide (cmWS, which satisfies equation (22), 150 ≤ h ≤ 5000 (22)

(6) The total external surface area S (m ² ) of the entire guide satisfies the formula (23).

2 ≤ S ≤ 50000 Equation (23)

An industrial process for producing high-quality aromatic polycarbonate, characterized by

2. The method according to item 1 above, wherein the aromatic polycarbonate produced is 1 ton or more per hour,

3. The d and d of the continuous multistage distillation column T used in step (I) satisfy the formula (24)

0 01 02

The method according to item 1 or 2, wherein

1 ≤ d / d ≤ 5 Equation (24)

01 02

4.L, D, L / D, n, D / d, D / d of the continuous multistage distillation column T are

0 0 0 0 0 0 0 01 0 02

2300≤L ≤6000, 200≤D ≤1000, 5≤L / Ό ≤30, 30≤η ≤100,

0 0 0 0 0

4≤D / ά ≤15, 7≤D / ά ≤25

0 01 0 02

, The method described in one of the above,

5.L, D, L / D, n, D / d, D / d of the continuous multistage distillation column

0 0 0 0 0 0 0 01 0 02

2500≤L ≤5000, 210≤D ≤800, 7≤L / Ό ≤20, 40≤η ≤90, 5

0 0 0 0 0

Any of items 1 to 4 above, wherein ≤Ό / ά ≤13, 9≤D / ά ≤20

0 01 0 02

The method according to any one of the above,

6.Continuous multistage distillation column Repulsion Has internal and tray and / or packing

0

The method according to any one of 1 to 5 above, which is a distillation column

7. The continuous multistage distillation column Τ is a tray type distillation column having a tray as the internal

0

The method according to item 6 above, characterized in that:

8. The continuous multistage distillation column The perforated plate tray having a perforated plate portion and a downcomer portion

0

8. The method according to item 6 or 7, wherein the method is a ray.

9. The perforated plate tray of the continuous multi-stage distillation column is 100-1 per lm ^{2 of the} perforated plate portion.

0

The method according to item 8 above, which has 000 holes,

10. Cross-sectional area per hole of the perforated plate tray of the continuous multi-stage distillation column T is 0.5-5cm

0

^2. The method according to item 8 or 9, wherein 1 1. Opening ratio of the perforated plate tray of the continuous multistage distillation column τ (total with respect to the area of the perforated plate portion)

0

11. The method according to any one of items 8 to 10 above, wherein the ratio of the hole cross-sectional area is 1.5 to 15%;

12. The first continuous multistage distillation column used in step (II) and the first continuous multistage distillation column d and

11 wherein d satisfies equation (25), and d and d satisfy equation (26)

12 21 22

The method according to any one of 1 to 1;

1 ≤ d / d ≤ 5 Equation (25)

12 11

1 ≤ d / d ≤ 6 Equation (26)

21 22

13. L, D, L / D, n, D / d of the first continuous multistage distillation column used in step (II)

, D / ά force S, 2000≤L ≤6000, 150≤D ≤1000, 3≤L / Ό ≤3 0, 30≤η ≤100, 8≤D / ά ≤25, 5≤D / ά ≤18 And

1 1 11 1 12

L, D, L / D, n, D / d, D / d of the second continuous multistage distillation column are 2 respectively.

2 2 2 2 2 2 21 2 22

000≤L ≤6000, 150≤D ≤1000, 3≤L / D ≤30, 15≤n ≤60, 2.5

2 2 2 2 2

≤D / d ≤12, 7≤D / d ≤25

2 21 2 22

Or the method according to claim 1.

14.L, D, L / D, n, D / d, D / d of the first continuous multi-stage distillation column are

1 1 1 1 1 1 11 1 12

2500≤L≤5000, 200≤D≤800, 5≤L / D≤15, 40≤n≤90, 10≤D / d≤25, 7≤D / d≤15, and L of 2 continuous multi-stage distillation column,

1 11 1 12 2

D, L / Ό, n, D / d, D / d are 2500≤L≤5000, 200≤D, respectively

2 2 2 2 2 21 2 22 2 2

≤800, 5≤L / D ≤15, 20≤n ≤50, 3≤D / d ≤10, 9≤D / d ≤2

2 2 2 2 21 2 22

The method according to any one of items 1 to 13 above, characterized in that it is 0,

15. Any one of items 1 to 14 above, wherein the first continuous multistage distillation column and the second continuous multistage distillation column are distillation columns each having a tray and / or a packing as the internal. The method according to the paragraph,

16. The first continuous multistage distillation column is a tray-type distillation column having a tray as the internal, and the second continuous multistage distillation column is a distillation column having both a packing and a tray as the internal. 15. The method according to item 15 above, wherein

17. Each of the trays of the first continuous multistage distillation column and the second continuous multistage distillation column is 17. The method according to item 15 or 16 above, wherein the tray is a perforated plate tray having a perforated plate portion and a downcomer portion.

18. Before the first continuous multi-stage distillation column and the second continuous multi-stage distillation column, the perforated plate tray has 100 to 1000 holes per area lm ² of the multi-hole plate portion. The method according to paragraph 17,

19. The cross-sectional area per hole of the perforated plate tray of the first continuous multistage distillation column and the second continuous multistage distillation column is 0.5 to ⁵ cm ² , Method,

20. The method according to item 15 or 16 above, wherein the second continuous multi-stage distillation column is a distillation column having a packing at the upper part and a tray at the lower part as the internal,

21. The method according to any one of items 15 to 20 above, wherein the packing of the internal of the second continuous multistage distillation column is one or two or more ordered packings,

22. The ordered packing of the second continuous multi-stage distillation column is at least one selected from melapack, gempack, technopack, flexipack, sulza packing, good roll packing, and glitch grid force. 22. The method according to item 21 above,

23. The method according to any one of claims 1 to 22, wherein the diaryl carbonate purification step (III) is distillation,

24. In the guided contact flow type polymerization reactor used in step (IV), the side casing of the polymerization reaction zone is a cylindrical shape having an inner diameter D (cm) and a length L (cm), and is connected to the lower part thereof. The bottom casing has a tapered shape, and the lowermost discharge port of the tapered bottom casing has a cylindrical shape with an inner diameter d (cm), and D, L, and d are the formulas (27), (28) , (29) and (30) are satisfied,

100 ≤ D ≤ 1800 Formula (27)

5 ≤ D / d ≤ 50 Equation (28)

0.5 ≤ L / D ≤ 30 (29)

h-20 ≤ L ≤ h + 300 (30)

The method according to any one of the preceding items;

25. The h of the guide satisfies the formula (31). 400 <h ≤ 2500 formula (31)

The method according to any one of the preceding items, characterized in that;

26. One of the guides is a cylindrical shape having an outer diameter r (cm) or a pipe shape in which a molten prepolymer is prevented from entering inside, and r satisfies the formula (32).

0. 1 ≤ r ≤ 1 (32)

The method according to any one of the preceding paragraphs, characterized in that

27. The method according to any one of claims 1 to 26, wherein in step (IV), polymerization is carried out by connecting two or more guide contact flow type polymerization reactors.

28. The two or more guide contact flow type polymerizers according to claim 27 are two polymerizers of a guide contact flow type first polymerizer and a guide contact flow type second polymerizer, the degree of polymerization in this order. The total external surface area SI (m ² ) of the entire guide of the first polymerization vessel and the external total surface area S2 (m ² ) of the entire guide of the second polymerization vessel satisfy the formula (33). To

1 ≤ S1 / S2 ≤ 20 Equation (33)

28. The method according to item 27 above,

I will provide a.

[0031] In the second aspect of the present invention,

29. A high-quality aromatic polycarbonate produced by 1 ton or more per hour by any one of the methods 1 to 28 above,

30. When the content power of alkali metal and / or alkaline earth metal compound is converted to these metal elements, it is 0.;! To 0. Olppm, and the halogen content is less than lppb. 29. The high-quality aromatic polycarbonate according to item 29,

31. An aromatic polycarbonate partially branched from the main chain through a hetero bond such as an ester bond or an ether bond, and the content of the hetero bond is 0. 05-0. High-quality aromatic polycarbonate according to item 29 or 30, characterized by being 5 mol%,

I will provide a.

The invention's effect

[0032] By carrying out the method of the present invention, a cyclic carbonate and an aromatic dihydroxy compound are combined. It has been found that high-quality, high-performance aromatic polycarbonates with no coloring and excellent mechanical properties can be produced on an industrial scale of 1 ton or more per hour at a high polymerization rate. It has also been found that high-quality aromatic polycarbonates can be stably produced over a long period of time with little variation in molecular weight, such as 2000 hours or more, preferably 3 000 hours or more, more preferably 5000 hours or more. Therefore, the present invention is an extremely effective method as an industrial production method for high-quality aromatic polycarbonate.

BEST MODE FOR CARRYING OUT THE INVENTION

[0033] The present invention will be specifically described below.

In the present invention, first, step (I) for continuously producing dialkyl carbonate and diol on an industrial scale from cyclic carbonate and aliphatic monohydric alcohol is performed. The reaction in step (I) is a reversible transesterification reaction represented by the following formula.

[0034] [Chemical 1]

R ¹ R2Q OR ² R1

+ 2R20H ゝ + _H0 , ヽ_0H II

»0

0

[0035] (wherein R ¹ represents a divalent group — (CH 2) − (k is an integer of 2 to 6),

2k

The element may be substituted by an alkyl group having 1 to 10 carbon atoms or a carbaryl group. R ² represents a monovalent aliphatic group having 1 to 12 carbon atoms, and one or more hydrogen atoms thereof may be substituted with an alkyl group having 1 to 10 carbon atoms or a aryl group. )

[0036] Examples of such cyclic carbonates include alkylene carbonates such as ethylene carbonate and propylene power carbonate, 1,3-dioxacyclohexan 2-one, 1,3-dioxacyclohepter 2- On and the like are preferably used, ethylene carbonate and propylene carbonate are more preferably used from the viewpoint of easy availability, and ethylene carbonate is particularly preferably used.

[0037] As the aliphatic monohydric alcohols, those having a boiling point lower than that of the generated diols are used. Therefore, although it may vary depending on the type of cyclic carbonate used, for example, methanol, ethanol, propanol (each isomer), aryl alcohol, butano (Each isomer), 3-butene 1 ol, amyl alcohol (each isomer), hexyl alcohol (each isomer), heptyl alcohol (each isomer), octyl alcohol (each isomer), nonyl Alcohol (each isomer), decyl alcohol (each isomer), undecyl alcohol (each isomer), dodecyl alcohol (each isomer), cyclopentanol, cyclohexanol, cycloheptanonore, cyclootanonore, methinore Cyclopentano monore (each isomer), ethylcyclopentanol (each isomer), methylcyclohexanol (each isomer), ethylcyclohexanol (each isomer), dimethylcyclohexanol (each isomer) , Jetylcyclohexanol (each isomer), Phenylcyclohexanol (each isomer), Benzyl Examples include alcohol, phenethyl alcohol (each isomer), and phenylpropanol (each isomer). Further, in these aliphatic monohydric alcohols, halogen, lower alkoxy group, cyan group, alkoxycarbonyl group, It may be substituted with a substituent such as aryloxycarbonyl group, acyloxy group, nitro group.

[0038] Among such aliphatic monohydric alcohols, alcohols having 1 to 6 carbon atoms are preferably used, and more preferably methanol, ethanol, propanol (each heterogeneous substance), butanol ( Each isomer) is an alcohol having 1 to 4 carbon atoms. When ethylene carbonate or propylene carbonate is used as the cyclic carbonate, methanol and ethanol are preferable, and methanol is particularly preferable.

[0039] In carrying out the reactive distillation in step (I), any method may be used for allowing the catalyst to be present in the reactive distillation column. In the case of a homogeneous catalyst, the catalyst can be present in the liquid phase in the reactive distillation column by continuously supplying the catalyst into the reactive distillation column, or it does not dissolve in the reaction solution under the reaction conditions. In the case of such a heterogeneous catalyst, a catalyst can be present in the reaction system by disposing a solid catalyst in the reactive distillation column, or a method using these in combination.

[0040] When the homogeneous catalyst is continuously supplied into the reactive distillation column, it may be supplied simultaneously with the cyclic carbonate and / or the aliphatic monohydric alcohol, or supplied at a position different from the raw material. May be. Since the reaction actually proceeds in the distillation column is a region under the catalyst supply position force, it is preferable to supply the catalyst to a region between the top of the column and the raw material supply position. The stage where the catalyst exists must be at least 5 stages, preferably 7 More than 10 stages, more preferably more than 10 stages.

[0041] When a heterogeneous solid catalyst is used, the number of stages in which the catalyst exists needs to be 5 or more, preferably 7 or more, and more preferably 10 or more. . A solid catalyst that also has an effect as a packing for a distillation column can be used.

[0042] Examples of the catalyst used in the step (I) include:

Alkali metals and alkaline earth metals such as lithium, sodium, potassium, norevidium, cesium, magnesium, canoleum, strontium, barium;

Basic compounds such as alkali metal and alkaline earth metal hydrides, hydroxides, alkoxides, aryl-oxides, amidates, etc .;

Basic compounds such as alkali metal and alkaline earth metal carbonates, bicarbonates, organic acid salts;

Tertiary amines such as trichinoleamine, tribubutenoleamine, trihexenoleamine, benzyljetylamine;

N-alkylpyrrolone, N-alkylindanol, oxazole, N-alkylimidazole, N-alkylpyrazole, oxadiazole, pyridine, alkylpyridine, quinoline, alkylquinoline, isoquinoline, alkylisoquinoline, atalidine, alkylacridine, phenanthorin, Nitrogen-containing heteroaromatic compounds such as alkylphenantorin, pyrimidine, alkylpyrimidine, pyrazine, alkylvilazine, triazine, alkyltriazine;

Cyclic amidines such as diazabicycloundecene (DBU) and diazabicyclononene (DBN);

Thallium compounds such as thallium oxide, thallium halide, thallium hydroxide, thallium carbonate, thallium nitrate, thallium sulfate, organic acid salts of thallium;

Such as tributyl methoxytin, tributyl ethoxy tin, dibutyl dimethoxy tin, jetyl methoxy tin, dibutyl methoxy tin, dibutyl phenoxy tin, diphenyl methoxy tin, dibutyl tin acetate, tributyl tin chloride, tin 2-ethylhexanoate, etc. Tin compounds;

Dimethoxy nitro diethoxy nitro ethylene bismuth, dibutoxy dumbbell, etc. dumbbell compounds; Aluminum compounds such as aluminum trimethoxide, aluminum triisopropoxide, aluminum tributoxide;

Tetramethoxytitanium, tetraethoxytitanium, tetrabutoxytitanium, dichlorodimethoxytan compounds;

Phosphorus compounds such as trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tributylmethylphosphonium halide, trioctylbutylphosphonium halide, triphenylmethylphosphonium halide;

Zirconium compounds such as zirconium halide, zirconium acetyl cetate, zirconium alkoxide, zirconium acetate;

Lead and compounds containing lead, for example, lead oxides such as PbO, PbO, PbO; PbS

2 3 4

, Pb S, PbS and other lead sulfides; Pb (〇H), Pb O (OH), Pb [PbO (OH)], P

2 3 2 2 3 2 2 2 2 2 Lead hydroxides such as b〇 (〇H); Na PbO, K PbO, NaHPbO, KHPbO, etc.

2 2 2 2 2 2 2 2 Nymaliates; Na PbO, Na H PbO, K PbO, K [Pb (OH)], K PbO, Ca

2 3 2 2 4 2 3 2 6 4 4

Lead salts such as PbO and CaPbO; Mouth carbonates such as PbC〇, 2PbCO -Pb (OH)

2 4 3 3 3 2

And its basic salts: Pb (〇CH), (CH 2 O) Pb (OPh), Pb (OPh), etc.

3 2 3 2

Coxileads, aryloxyleads; Pb (〇C〇CH), Pb (〇C〇CH), Pb (〇C〇C)

3 2 3 4

H) -PbO-Lead salts of organic acids such as 3H O and their carbonates and basic salts; Bu Pb, P

3 2 2 4 h Pb, Bu PbCl, Ph PbBr, Ph Pb (or Ph Pb), Bu PbOH, Ph PbO, etc.

4 3 3 3 6 2 3 2

Organic lead compounds (Bu represents butyl group, Ph represents phenyl group); Lead alloys such as Pb—Na, Pb—Ca, Pb—Ba, Pb—Sn, Pb—Sb;

And lead minerals such as howenite and senyanite, and hydrates of these lead compounds.

These compounds can be used as homogeneous catalysts when they are dissolved in reaction raw materials, reaction mixtures, reaction byproducts, etc., and can be used as solid catalysts when they are not dissolved. Furthermore, it is also preferable to use a mixture obtained by dissolving these compounds in advance with reaction raw materials, reaction mixtures, reaction by-products or the like, or using a mixture obtained by reaction as a homogeneous catalyst. Is the method. [0044] Further, an anion exchange resin having a tertiary amino group, an ion exchange resin having an amide group, an ion exchange resin having at least one exchange group of a sulfonic acid group, a carboxylic acid group, and a phosphoric acid group, Ion exchangers such as solid strongly basic anion exchangers with quaternary ammonium groups as exchange groups; silica, silica-alumina, silica-magnesia, aluminosilicates, gallium silicates, various zeolites, various metal-exchanged zeolites, Solid inorganic compounds such as ammonium exchanged zeolites are used as catalysts.

[0045] As the solid catalyst, a solid strong basic anion exchanger having a quaternary ammonium group as an exchange group is particularly preferably used. Examples of such a solid catalyst include a quaternary ammonium group as an exchange group. Strong basic anion exchange resin, cellulose strong basic anion exchanger having a quaternary ammonium group as an exchange group, inorganic carrier-supported strong basic anion exchange having a quaternary ammonium group as an exchange group, etc. Are listed. As the strongly basic anion exchange resin having a quaternary ammonium group as an exchange group, for example, a styrenic strongly basic anion exchange resin is preferably used. A styrene-based strong base anion exchange resin is a strong base anion exchange resin having a quaternary ammonium (type I or type II) as an exchange group based on a copolymer of styrene and dibutenebenzene. For example, it is schematically shown by the following formula.

[0046] [Chemical 2]

[0047] In the formula, X represents an anion, and usually X is F_, Cl_, Br_, 厂, HCO_, CO

3 3

, CH CO-, HCO-, IO-, BrO-, CIO-

3 2 2 3 3 3

Two on are used, preferably Cl_, Br_, HCO _, the least selected from among CO ² _

3 3

Also one kind of anion is used. In addition, as the structure of the resin matrix, gel type, macroreticular type (MR type) V, the ability to use misalignment, high resistance to organic solvents, and MR type are particularly preferred from the viewpoint.

[0048] Examples of the strong cellulose basic anion exchanger having a quaternary ammonium group as an exchange group include, for example, OCH CH NR obtained by trialkylaminoethylation of a part or all of —OH groups of cellulose. Examples thereof include cellulose having an exchange group of X.

2 2 3

However, R represents an alkyl group, and methyl, ethyl, propyl, butyl, etc. are usually used, and methyl and ethyl are preferably used. X represents an anion as described above.

[0049] An inorganic carrier-supported strong basic cation exchange having a quaternary ammonium group as an exchange group is a quaternary ammonium group by modifying part or all of the surface hydroxyl group OH of the inorganic carrier. 〇 (CH) This means that NR X is introduced. However, R and X are

2 n 3

As described above. n is usually an integer of 1 to 6, preferably n = 2. As the inorganic carrier, silica, alumina, silica alumina, titania, zeolite, and the like can be used, preferably silica, alumina, silica alumina, and particularly preferably silica. As a method for modifying the surface hydroxyl group of the inorganic carrier, any method can be used.

[0050] Commercially available solid strongly basic ayuone exchangers having a quaternary ammonium group as an exchange group can also be used. In that case, it can be used as a transesterification catalyst after ion exchange with a desired anion species in advance as a pretreatment.

[0051] Further, from a macroreticular and gel-type organic polymer to which a heterocyclic group containing at least one nitrogen atom is bonded, or from an inorganic carrier to which a heterocyclic group containing at least one nitrogen atom is bonded. The solid catalyst is preferably used as a transesterification catalyst. Furthermore, solid catalysts in which some or all of these nitrogen-containing heterocyclic groups are quaternized are also used. In addition, solid catalysts such as ion exchangers function as packing materials. Achieving power S

[0052] The amount of the catalyst used in step (I) varies depending on the type of catalyst used, but when a homogeneous catalyst that is dissolved in the reaction solution under the reaction conditions is continuously supplied, a percentage of the total mass of the cyclic carbonate and an aliphatic monohydric alcohol as a raw material to Table Wa, usually 0.000;! ~ 50 weight ^_0/0, preferably from 0.005 to 20 mass ^_0/0, more preferably 0 01 ~; Used at 10% by mass. When a solid catalyst is used in the distillation column, it is 0.0;! To 75% by volume, preferably 0.05 to 60% by volume with respect to the empty volume of the distillation column. More preferably, 0.;! ~ 60% by volume of catalyst is preferably used.

[0053] In step (I), the continuous multistage distillation column T, which is a reactive distillation column, is added to the cyclic carbon as a raw material.

0

With regard to the method for continuously supplying the nate and the aliphatic monohydric alcohol, there is no particular limitation that they are catalysts in the region of at least 5 or more, preferably 7 or more, more preferably 10 or more of the distillation column. Any supply method can be used as long as it can be brought into contact with the substrate. In other words, the cyclic carbonate and the aliphatic monohydric alcohol can be continuously supplied from the necessary number of inlets to the stage satisfying the above conditions of the continuous multistage distillation column. Further, the cyclic carbonate and the aliphatic monohydric alcohol may be introduced into the same stage of the distillation column, or may be introduced into different stages.

[0054] The cyclic carbonate and aliphatic monohydric alcohol as raw materials are continuously supplied to the continuous multistage distillation column T as a liquid, a gas, or a mixture of a liquid and a gas. In this way

0

In addition to supplying the raw material to the distillation column, it is also preferable to supply a gaseous raw material from the lower portion of the distillation column intermittently or continuously. In addition, cyclic carbonate is continuously supplied to the distillation column in a liquid or gas-liquid mixed state to the upper stage from the stage where the catalyst exists, and the aliphatic monohydric alcohol is gaseous and / or lower to the lower part of the distillation tower. Alternatively, a continuous supply method in a liquid state is also a preferable method. In this case, it goes without saying that an aliphatic monohydric alcohol is contained in the cyclic carbonate.

[0055] In step (I), the feedstock may contain dialkyl carbonate and / or diol as the product. The content of the dialkyl carbonate is usually 0 to 40% by mass, preferably 0 to 30% by mass, and more preferably represented by the mass% of dialkyl carbonate in the aliphatic monohydric alcohol / dialkyl carbonate mixture. Preferably, it is 0 to 20% by mass, and the diol is represented by mass% in the cyclic carbonate / diol mixture, and is usually 0 to; 10% by mass, preferably 0 to 7% by mass, and more preferably 0 to 5%. % By mass.

[0056] When the reaction of step (I) is carried out industrially, in addition to the cyclic carbonate and / or aliphatic monohydric alcohol newly introduced into the reaction system, it is recovered in this step or / and other processes. It is preferable that the material mainly composed of cyclic carbonate and / or aliphatic monohydric alcohol can be used as these raw materials. The present invention makes this possible and is an excellent feature of the present invention. The other process includes, for example, a process (II) for producing diaryl carbonate from a dialkyl carbonate and an aromatic monohydroxy compound. In this process (II), an aliphatic monohydric alcohol is by-produced. Is collected. This recovered by-product aliphatic monohydric alcohol usually contains dialkyl carbonates, aromatic monohydroxy compounds, alkylaryl ethers, etc., and even small amounts of alkylaryl carbonates, diaryl carbonates, etc. May occur. The by-product aliphatic monohydric alcohol can be used as it is as the raw material for step (I), or after the content of substances having a boiling point higher than that of the aliphatic monohydric alcohol is reduced by distillation or the like (I ).

[0057] Further, preferable cyclic carbonates used in the step (I) are those produced by reaction of alkylene oxide such as ethylene oxide, propylene oxide and styrene oxide with carbon dioxide, One round carbon dioxide containing a small amount of the above compound can be used as a raw material for the step (I).

[0058] In step (I), the amount ratio between the cyclic carbonate and the aliphatic monohydric alcohol supplied to the reactive distillation column varies depending on the type and amount of the transesterification catalyst and the reaction conditions, but is usually supplied. The aliphatic monohydric alcohols can be supplied in a molar ratio of 0.01 to 1000 times with respect to the cyclic carbonate. In order to increase the reaction rate of the cyclic carbonate, it is preferable to supply an excess of aliphatic monohydric alcohols in an amount of 2 times or more. When 1S is used in a very large excess, it is necessary to enlarge the apparatus. In this sense, the molar ratio of the aliphatic monohydric alcohol to the cyclic carbonate is preferably 2 to 20, more preferably 3 to 15, and even more preferably 5 to 12; Unreacted annular carbon If a large amount of acid remains, it reacts with the product diols to produce by-products such as dimers and trimers. Is preferably reduced as much as possible. In the method of the present invention, even when the molar ratio is 10 or less, the reaction rate of the cyclic carbonate can be 97% or more, preferably 98% or more, and more preferably 99% or more. This is also one of the features of the present invention.

[0059] In step (I), preferably a force that continuously produces about 0.4 tons or more of dialkyl carbonate per hour. The amount is usually 0.44 tons / hr, preferably 0.42 tons / hr, more preferably 0.4 tons / hr, relative to the amount of aromatic polycarbonate to be produced (P tons / hr). is there . In a more preferred case, it can be less than 0 · 39 P ton / hr.

[0060] The continuous multistage distillation column T used in step (I) is a length (cm) and an inner diameter D (cm).

Has a cylindrical body of 0 0 0, and has an internal structure with an internal number n of stages,

0

At the top of the tower or near the top of the tower is a gas outlet with an inner diameter d (cm), the bottom of the tower or

01

A liquid outlet with an inner diameter d (cm) at the lower part of the tower close to this, and below the gas outlet,

02

One or more first inlets in the upper part and / or middle part of the tower, and one or more second inlets in the middle part and / or lower part of the tower above the liquid outlet. L, D, L / D, n, D / d, D / d forces satisfy the formulas (;!) To (6) respectively.

0 0 0 0 0 0 01 0 02

It is necessary to be.

2100 <L <8000 (1)

0

180 <D <2000 (2)

0

4 <L /) ≤ 40 (3)

0 0

10 <n <120 (4)

0

3 <D, Zd ≤ 20 (5)

0 01

5 <D, Zd ≤ 30 (6)

The term “top of the tower or near the top of the tower” used in the present invention means a portion of about 0.25 L downward from the top of the tower, and the term “bottom of the tower or near the bottom of the tower”

0

Means the portion up to about 0.25 L from the bottom of the tower. (First and second continuous multistage

0

In the distillation column, it is 0 · 25L and 0 · 25L respectively. ) [0062] A continuous multi-stage distillation column T that simultaneously satisfies the formulas (1), (2), (3), (4), (5) and (6) is used.

0 from the cyclic carbonate and the aliphatic monohydric alcohol, the dialkyl strength-bonate is preferably 0.4 ton or more and / or the diol is preferably 0.26 ton or more per hour. Since it was found that it can be stably produced for a long period of time, such as 1000 hours or more, preferably 3000 hours or more, and more preferably 5000 hours or more, on an industrial scale, with a high reaction rate and high selectivity. is there. The reason why it is possible to produce dialkyl carbonates and diols on an industrial scale having such excellent effects by carrying out the step (I) is not clear! ) To (6) are presumed to be due to the combined effect. The preferred range of each factor is shown below.

[0063] If L (cm) is less than 2100, the reaction rate decreases and the target production volume can be achieved.

0

In addition, L must be 8000 or less in order to reduce equipment costs while ensuring a reaction rate that can achieve the target production volume. The more preferable range of L (cm) is 2300≤L≤

0 0 0

6000, more preferably 2500≤L≤5000.

0

If D (cm) is smaller than 180, the target production volume cannot be achieved and the target production volume

0

In order to reduce equipment costs while achieving the above, D must be 2000 or less. Yo

0

The preferred range of D (cm) is 200≤D ≤1000, more preferably 210≤D

0 0

≤800.

0

[0064] When L / repulsive force is less than or greater than 40, stable operation becomes difficult, especially greater than 40

0 0

Since the pressure difference between the top and bottom of the tower becomes too large, long-term stable operation becomes difficult, and the temperature at the bottom of the tower must be increased, which leads to side reactions and lowers selectivity. . The more preferred range of L / Ό is 5≤L / Ό ≤30

0 0 0 0

More preferably, 7≤L / Ό≤20.

0 0

[0065] If n is less than 10, the reaction rate decreases and the target production volume cannot be achieved.

0

In order to reduce the equipment cost while ensuring the reaction rate that can achieve the desired production volume, n is not less than 120.

0 Must be down. Furthermore, if the n force is greater than 20, the pressure difference between the top and bottom of the tower

0

As the temperature becomes too large, the temperature at the bottom of the tower must be increased as well as long-term stable operation becomes difficult, and side reactions are likely to occur, leading to a decrease in selectivity. Yo The preferred range of n is 30≤n≤100, more preferably 40≤n≤90.

0 0 0 d * o

[0066] If the D / ά force is less than ¾, not only will the equipment cost be high, but a large amount of gas components may be removed from the system.

0 01

Therefore, stable operation becomes difficult, and if it is greater than 20, the amount of gas components extracted becomes relatively small, which leads to a decrease in reaction rate as well as difficulty in stable operation. The more preferred range of D / d is 4≤D / d≤15, and more preferably 5≤D / d

0 01 0 01 0 01

≤13.

[0067] If D / ά power ^ is smaller, not only will the equipment cost increase, but the amount of liquid drained will be relatively large.

0 02

Therefore, stable operation becomes difficult, and if it is larger than 30, the flow velocity at the liquid outlet and the piping increases rapidly, and erosion is likely to occur, resulting in corrosion of the device. More preferred D / d

The range of 0 02 is 7≤D / d≤25, more preferably 9≤D / d≤20.

0 02 0 02

[0068] Further, the d and d of the continuous multistage distillation column T used in the step (I) satisfy the formula (24).

0 01 02

When this is the case, it is more preferable.

1 ≤ d / d ≤ 5 Equation (24)

01 02

[0069] The long-term stable operation in the process (I) is based on operating conditions where there is no flooding, piping clogging or erosion for 1000 hours or more, preferably 3000 hours or more, more preferably 5000 hours or more! This means that a certain amount of dialkyl carbonate and diol can be produced while maintaining a high reaction rate, high selectivity, and high productivity.

[0070] In the step (I), the selectivity of the dialkyl carbonate and the diol is relative to the reacted cyclic carbonate, and in the present invention, the selectivity is usually 95% or more, preferably 97%. As described above, a high selectivity of 99% or more can be achieved. The reaction rate in the step (I) usually represents the reaction rate of the cyclic carbonate. In the present invention, the reaction rate of the cyclic carbonate is 95% or more, preferably 97% or more, more preferably 99% or more, and further It is preferably 99.5 or more, and even more preferably 99.9% or more. One of the excellent features of step (I) is that a high reaction rate can be achieved while maintaining a high selectivity.

[0071] The continuous multi-stage distillation column T used in step (I) is used as an internal tray and / or Is preferably a distillation column with packing. The term “internal” as used in the present invention means a portion where the gas-liquid contact is actually performed in the distillation column. As such a tray, for example, a foam tray, a perforated plate tray, a valve tray, a counter-flow tray, a super flack tray, a max flack tray, etc. are preferred fillings such as Raschig rings, less rings, pole rings, Berle saddles. Irregular packing such as Interlocks saddle, Dixon packing, McMahon packing, Helipac, etc. and regular packing such as Melapack, Gempack, Technoback, Flexipack, Snow Leather Packing, Goodronor Packing, Glitch Grid etc. Les. A multi-stage distillation column having both a tray part and a part filled with packing can also be used. Further, the term “internal plate number n” in the present invention means the number of trays in the case of trays, and the theoretical plate number in the case of packing.

Yes

Therefore, in the case of a multi-stage distillation column having both a tray part and a packed part, the number of stages n is the sum of the number of trays and the number of theoretical stages.

[0072] In the step (I) of reacting the cyclic carbonate and the aliphatic monohydric alcohol, the continuous continuous multi-stage distillation column and / or the packing comprising a tray and / or a packing having a predetermined number of internal plates High reaction rate using any of the tower-type continuous multistage distillation columns

• High selectivity • The ability to achieve high productivity, the internal distillation column-type distillation column was found to be more preferable. Furthermore, it has been found that a perforated plate tray having a perforated plate portion and a downcomer portion is particularly excellent in terms of function and equipment cost. It was also found that the perforated plate tray preferably has 100 to 1000 holes per area lm ² of the perforated plate portion. More preferably, the number of holes is 120 to 900 per lm ² , and more preferably 150 to 800. It has also been found that the cross-sectional area per hole of the perforated plate tray is preferably 0.5 to ⁵ cm ² . The cross-sectional area per hole is more preferably 0.7 to ⁴ cm ² , and further preferably 0.9 to ³ cm ² . Further, the perforated plate tray has 100 to 1000 holes per lm ² area of the perforated plate portion, and has a cross-sectional area of 0.5 to ⁵ cm ² per hole. In particular, it has been found to be particularly preferred.

[0073] Further, it has been found that the aperture ratio of the perforated plate tray is preferably 1.5 to 15%. It was. More preferably, the aperture ratio is 1.7 to 13%, and more preferably 1.9 to 11%. Here, the aperture ratio of the perforated plate tray represents the ratio of the cross-sectional area of all the holes existing in the perforated plate to the area of the perforated plate portion (total hole cross-sectional area). In each perforated plate tray, the force S may be different in the area of the perforated plate portion and / or the total hole cross-sectional area, and in this case also, the aperture ratio of each multi-holed plate tray is preferably in the above range. The number of holes in the perforated plate portion may be the same in all perforated plates, or may be different. By adding the above conditions to the continuous multi-stage distillation column T, the problem in step (I) can be made easier.

0

It was found that this was achieved.

[0074] When the step (I) is carried out, the cyclic carbonate as a raw material and the aliphatic monohydric alcohol are continuously fed into a continuous multistage distillation column in which a catalyst exists, and the reaction and distillation are carried out in the column. At the same time, the low-boiling reaction mixture containing dialkyl carbonate to be produced is continuously withdrawn in the form of gas from the top of the tower, and the high boiling point reaction mixture containing diols is continuously withdrawn in the form of liquid from the bottom of the tower. Diols are produced continuously.

[0075] Further, in step (I), in order to continuously supply the raw material cyclic carbonate and aliphatic monohydric alcohol into the continuous multistage distillation column T, the gas outlet at the top of the distillation column is more than

0

It may be supplied in liquid and / or gaseous form as a raw material mixture or separately from one or several inlets installed in the lower part but at the upper part or the middle part of the tower. The raw material containing a large amount thereof is supplied in the form of an introduction loca in the upper part or middle part of the distillation column, and the aliphatic monohydric alcohol or the raw material containing a large amount of the raw material is provided above the liquid outlet at the lower part of the distillation column. It is also preferable to supply it in the form of gas from the inlet installed in the middle or lower part.

[0076] The reaction time of the transesterification performed in the step (I) is the reaction time in the continuous multistage distillation column T.

0 It is thought that this corresponds to the average residence time of the reaction liquid, but this varies depending on the internal shape and number of stages of the distillation column, the amount of feed, the type and amount of the catalyst, the reaction conditions, etc. 20 hours, preferably 0.5 to 15 hours, more preferably;! To 10 hours.

[0077] The reaction temperature in the step (I) varies depending on the type of raw material compound used and the type and amount of the catalyst, and is usually 30 to 300 ° C. Increasing the reaction temperature to increase the reaction rate However, when the reaction temperature is high, side reactions are liable to occur. Preferred reaction temperatures range from 40 to 250 ° C, more preferably from 50 to 200 ° C, even more preferably from 60 to; In the present invention, the reaction distillation can be carried out at a column bottom temperature of 150 ° C. or lower, preferably 130 ° C. or lower, more preferably 110 ° C. or lower, and even more preferably 100 ° C. or lower. . Achieving high reaction rate, high selectivity, and high productivity even at such a low temperature / bottom temperature is one of the excellent features of process (I). The reaction pressure may vary depending on the type and composition of the raw material compound used, the reaction temperature, etc., and may be any of reduced pressure, normal pressure, and increased pressure, usually 1 Pa to 2 X 10 ⁷ Pa, preferably 10 ³ Pa. To 10 ⁷ Pa, more preferably 10 ^{4 to} 5 × 10 ⁶ .

[0078] The reflux ratio of the continuous multistage distillation column T in step (I) is usually from 0 to 10;

0

Is from 0.0;! To 5, more preferably from 0.05 to 3.

[0079] The material constituting the continuous multistage distillation column T used in step (I) is mainly carbon steel, stainless steel.

0

Stainless steel is preferred from the viewpoint of the quality of the metal material such as stainless steel and the quality of the dialkyl carbonate to be produced.

[0080] In the present invention, subsequently, step (II) for continuously producing diaryl carbonate on an industrial scale from the dialkyl carbonate produced in step (I) and the aromatic monohydroxy compound is performed. The dialkyl carbonate used in the step (II) is represented by the following formula described in the following formula.

R'OCOOR ²

Here, R ² is as described above.

Examples of such dialkyl carbonates having R ² include dimethyl carbonate, jetyl carbonate, dipropyl carbonate (each isomer), diaryl carbonate, dibutyr carbonate (each isomer), dibutyl carbonate (each Isomer), dipentyl carbonate (each isomer), dihexyl carbonate (each isomer), diheptyl carbonate (each isomer), dioctyl carbonate (each isomer), dinonyl carbonate (each Isomers), didecyl carbonate (each isomer), dicyclopentyl carbonate, dicyclohexenole carbonate, dicycloheptinole carbonate, dibenzino carbonate, diphenetino carbonate (each different organism), di (Fuenore propinore) carbonate (each Isomers), di (phenylbutyl) carbonate (each isomer) di (black benzyl) carbonate (each isomer), di (methoxybenzyl) carbonate (each isomer), di (methoxymethyl) carbonate, di ( Methoxyethyl) carbonate (each isomer), di (chloroethyl) carbonate (each isomer), di (cyanoethyl) carbonate (each isomer) and the like.

[0081] Of these, R ² is preferably a dialkyl carbonate composed of an alkyl group containing 4 or less carbon atoms that does not contain halogen, and dimethyl carbonate is particularly preferred. Among the preferred dialkyl carbonates, more preferred are dialkyl carbonates prepared in a substantially halogen-free state, for example, alkylene carbonate and halogen substantially free of halogen. Alcohol power not included in the product.

[0082] The aromatic monohydroxy compound used in the step (II) is represented by the following general formula, and any compound may be used as long as the hydroxyl group is directly bonded to the aromatic group. It may be.

Ar ³ OH

Here, Ar ³ represents an aromatic group having 5 to 30 carbon atoms. Examples of such aromatic monohydroxy compounds having Ar ³ include phenol, talesol (each isomer), xylenol (each isomer), trimethylphenol (each isomer), tetramethylphenol (each isomer), Ethylphenol (each isomer), propylphenol (each isomer), butylphenol (each isomer), jetylphenol (each isomer), methylethylphenol (each isomer), methylpropylphenol (each) Isomers), dipropylphenol (each isomer), methylbutinophenol (each isomer), pentylphenol (each isomer), hexylphenol (each isomer), cyclohexylphenol (each isomer), etc. Alkylphenols; methoxyphenol (each isomer), ethoxyphenol (each isomer), etc. Various alkoxyphenols; arylpropylphenols such as phenylpropylphenol (each isomer); naphthol (each isomer) and various substituted naphthols; hydroxypyridine (each isomer), hydroxycoumarin (each isomer) ), And heteroaromatic monohydroxy compounds such as hydroxyquinoline (each isomer).

[0083] These aromatic monohydroxy compounds are used as a mixture of one or more. That power S. Among these aromatic monohydroxy compounds, those preferably used in the present invention are aromatic monohydroxy compounds in which Ar ³ is an aromatic group having 6 to 10 carbon atoms, particularly preferably phenol. is there. Of these aromatic monohydroxy compounds, those that are preferably used in the present invention are those that do not substantially contain halogen.

Therefore, the diaryl carbonate as used in the present invention is generally represented by the following formula.

[0085] [Chemical 3]

0

II

Ar ^ -OCO-Ar ⁴

[In the formula, Ar ³ and Ar ⁴ each represent a monovalent aromatic group.]

Ar ³ and Ar ^{4 each} represent a monovalent carbocyclic or heterocyclic aromatic group. In Ar ³ and Ar ⁴ , one or more hydrogen atoms are other groups that do not adversely affect the reaction. Substituents such as halogen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, phenyl groups, phenoxy groups, bur groups, cyan groups, ester groups, amide groups, nitro groups, etc. It may be what was done. Ar ³ and Ar ⁴ may be the same or different. Representative examples of the monovalent aromatic groups Ar ³ and Ar ⁴ include a phenyl group, a naphthyl group, a biphenyl group, and a pyridyl group. These may be substituted with one or more substituents as described above.

Preferred examples of Ar ³ and Ar ⁴ include those represented by the following formulas, respectively.

[0088] [Chemical 4]

[0089] A particularly preferred diaryl carbonate is a substituted or unsubstituted diphenyl carbonate represented by the following formula.

[0090] [Chemical 5]

[0091] (wherein R ⁹ and R ^{1 ()} are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 10 to 10 carbon atoms, or a ring having 5 to 5 carbon atoms. 10 represents a cycloalkyl group or a phenyl group, p and q are integers of 1 to 5, and when p is 2 or more, each R ⁹ may be different, or q is 2 In the above case, each R ^{1 ()} may be different.

[0092] Among these diaryl carbonates, symmetrical diaryl carbonates such as unsubstituted diphenyl carbonate and lower alkyl-substituted diphenyl carbonates such as ditolyl carbonate and di-butyl phenyl carbonate are preferable. Particularly preferred is diphenyl carbonate having the simplest structure. These diallyl carbonates may be used alone or in combination of two or more! /, With respect to an aromatic monohydroxy compound of dialkyl carbonate used as a raw material in step (II). The amount ratio is preferably a molar ratio of 0. Outside this range, The amount of unreacted raw material that remains is increased with respect to the desired production amount of diaryl carbonate, which is not efficient, and a large amount of energy is required to recover them. In this sense, the molar ratio is preferably 0.5 to 5 forces, more preferably 0.8 to 3, and still more preferably!

[0094] In the present invention, a force that continuously produces 1 ton or more of aromatic polycarbonate per hour. For that purpose, a high-purity diaryl force of about 0.85 ton or more per hour is continuously applied. It needs to be manufactured. Therefore, in Step (II), the minimum amount of aromatic monohydroxy compound continuously supplied is usually 15 P ton / hr with respect to the amount of aromatic polycarbonate to be produced (P ton / hr). And preferably 13 P ton / hr, more preferably 10 P ton / hr. If more preferable, it can be less than 8P ton / hr

Yes

[0095] It should be noted that the dialkyl carbonate and aromatic monohydroxy compound used as raw materials in the step (II) each have high purity! /, Even if it is! /, And le, which contains other compounds. For example, it may contain a compound or reaction byproduct produced in the first continuous multistage distillation column or / and the second continuous multistage distillation column. When industrially implemented, these raw materials were recovered from the first continuous multistage distillation column and / or the second continuous multistage distillation column in addition to the dialkyl carbonate and aromatic monohydroxy compound newly introduced into the reaction system. It is preferable to use also. In the method of the present invention, the top component, which is a low boiling point reaction mixture in the second continuous multistage distillation column, is supplied to the first continuous multistage distillation column. In this case, the second column low boiling point reaction mixture may be supplied as it is to the first continuous multistage distillation column! /, Or after a part of the components are separated! / ,.

Accordingly, in the present invention that is industrially implemented, the raw materials supplied to the first continuous multistage distillation column include alcohols, alkylaryl carbonate, dialyl carbonate, alkylaryl ether, and the like. Further, the product is preferably used even if it contains a small amount of high-boiling by-products such as a fleece transfer product of alkylaryl carbonate or diallyl carbonate and its derivatives. In the present invention, for example, dimethyl carbonate as a dialkyl carbonate and phenol as an aromatic monohydroxy compound are used as raw materials. When producing diphenyl carbonate, it is preferable that the raw material contains methyl alcohol as a reaction product, methyl phenyl carbonate and diphenyl carbonate. Further, anisole is salicylic acid as a reaction byproduct. It may contain a small amount of phenyl, methyl salicylate and high-boiling by-products derived from these.

[0097] Furthermore, most of the aromatic monohydroxy compound used in step (II) is composed of the aromatic monohydroxy compound by-produced in step (IV) of the present invention. This by-product aromatic monohydroxy compound needs to be recycled to step (II) by step (V).

[0098] The diaryl carbonate produced in the step (II) is produced by the transesterification reaction between the dialkyl carbonate and the aromatic monohydroxy compound. This transesterification reaction involves one or two alkoxy compounds of the dialkyl carbonate. A group is exchanged with the aryloxy group of an aromatic monohydroxy compound to remove alcohols, and a disproportionation reaction that is a transesterification reaction between two molecules of the generated alkylaryl carbonate. The reaction to be converted is included. In the first continuous multi-stage distillation column of step (II), mainly alkylaryl carbonate is obtained, and in the second continuous multi-stage distillation column, this alkylaryl power is mainly obtained by the disproportionation reaction of the carbonate. And dialkyl carbonate. Since the diaryl carbonate obtained in the step (II) does not contain any halogen, it is important as a raw material for industrially producing the aromatic polycarbonate of the present invention. This is because if the amount of halogen present in the polymerization raw material is less than, for example, 1 ppm, the polymerization reaction is inhibited, the stable production of aromatic polycarbonate is inhibited, and the strength is also generated. This is because the physical properties of the aromatic polycarbonate are deteriorated and coloring is caused.

[0099] The catalyst used in the first continuous multistage distillation column and / or the second continuous multistage distillation column in step (II) is selected from the following compounds, for example.

<Lead compounds> Lead oxides such as PbO, PbO and PbO; Lead sulfides such as PbS and Pb S; Pb (

2 3 4 2

Lead hydroxides such as OH) and Pb 2 O (OH); Nymaleates such as Na PbO, K PbO, NaHPbO and KHPbO; Na PbO, Na H PbO, K PbO, K [Pb (OH)], K PbO,

2 3 2 2 4 2 3 2 6 4 4

Lead salts such as Ca PbO and CaPbO; Lead carbonates such as PbCO and 2PbCO 2 -Pb (OH) And its basic salts; Pb (OCOCH), Pb (OCOCH), Pb (OCOCH) -PbO-3H

3 2 3 4 3 2

Lead salts of organic acids such as O and their carbonates and basic salts; Bu Pb, Ph Pb, Bu PbCl, P

2 4 4 3 h Organic lead compounds such as PbBr, Ph Pb (or Ph Pb), Bu PbOH, Ph PbO (Butt

3 3 6 2 3 3

Butyl group, Ph represents a phenyl group. ); Pb (OCH), (CH 2 O) Pb (OPh), Pb (OPh

3 2 3

) Alkoxyleads such as Pb—Na, Pb—Ca, Pb—Ba, Pb—Sn, Pb—Sb, etc .; Lead minerals such as howenite, senyanite, and these Hydrates of lead compounds;

<Copper group metal compounds> CuCl, CuCl, CuBr, CuBr, Cul, Cul, Cu (OAc), Cu (acac), copper oleate, Bu Cu, (CH 2 O) Cu, AgNO, AgBr, silver picrate, A

2 2 3 2 3

Salts and complexes of copper group metals such as gC H CIO, [AuC≡C-C (CH)] n, and [Cu (C H) C1]

6 6 4 3 3 7 8 4

(Acac represents a acetylacetone chelate ligand);

<Alkali metal complexes> Alkali metal complexes such as Li (acac) and LiN (C H);

4 9 2

<Zinc complex> Zinc complex such as Zn (acac);

Cadmium complexes> Cd (acac) and other cadmium complexes;

<Compounds of iron group metals> Fe (C H) (CO), Fe (CO), Fe (C H) (CO), Co (Me

10 8 5 5 4 6 3 Citylene) (PEt Ph), CoC F (CO), Ni-π—C H N〇, Huekousen, etc.

2 2 2 5 5 7 5 5

A complex of the genus;

<Zirconium complex> Zr complexes such as Zr (acac) and zirconocene;

Four

<Lewis acid compounds> A1X, TiX, TiX, VOX, VX, ZnX, FeX, SnX (here

3 3 4 3 5 2 3 4, X is halogen, acetoxy group, an alkoxy group or an aryloxy group. ) And the like, a transition metal compound that generates Lewis acid and Lewis acid;

<Organic tin compounds> (CH) SnOCOCH, (C H) SnOCOC H, Bu SnOCO

3 3 3 2 5 3 6 5 3

CH, Ph SnOCOCH, Bu Sn (OCOCH), Bu Sn (OCOC H), Ph SnOC

3 3 3 2 3 2 2 11 23 2 3

H, (C H) SnOPh, Bu Sn (OCH), Bu Sn (OC H), Bu Sn (OPh), Ph Sn

3 2 5 3 2 3 2 2 2 5 2 2 2 2

(OCH), (C H) SnOH, Ph SnOH, Bu SnO, (C H) SnO, Bu SnCl, Bu

3 2 2 5 3 3 2 8 17 2 2 2

Organotin compounds such as SnO (OH);

A metal-containing compound such as is used as a catalyst. These catalysts may be solid catalysts fixed in a multistage distillation column! /, Or may be soluble catalysts that dissolve in the reaction system! /. Of course, organic compounds in which these catalyst components are present in the reaction system, for example, aliphatic alcohols, aromatic monohydroxy compounds, alkylaryl carbonates, diaryl carbonates, dialkyl carbonates, etc. It may have been reacted, or may have been heat-treated with raw materials or products prior to the reaction.

[0101] When the step (II) is carried out with a soluble catalyst that dissolves in the reaction system, these catalysts must be under the reaction conditions! / And have high solubility in the reaction solution! /. I like it! Preferred catalysts in this sense include, for example, PbO, Pb (OH), Pb (OPh); TiCl, Ti (OMe), (M

2 2 4 4 eO) Ti (OPh), (MeO) Ti (OPh), (MeO) Ti (OPh), Ti (OPh); SnCl, Sn (

3 2 2 3 4 4

OPh), Bu SnO, Bu Sn (OPh); FeCl, Fe (OH), Fe (OPh), etc., or these

4 2 2 2 3 3 3 Examples include those treated with phenol or reaction solution. The catalyst used in the first continuous multistage distillation column and the catalyst used in the second continuous multistage distillation column may be the same or different.

[0102] The first continuous multi-stage distillation column used in step (II) is a cylindrical body having a length L (cm) and an inner diameter D cm), and an internal having n stages inside. A gas outlet with an inner diameter d (cm) at the top of the tower or near the top of the tower, the bottom of the tower or

11

Is a liquid outlet with an inner diameter d (cm) at the lower part of the tower close to it, below the gas outlet.

12

One or more third inlets in the upper and / or middle part of the tower, and one or more fourth inlets in the middle and / or lower part of the tower above the liquid outlet. L, D, L / D, n, D / d, D / d force, respectively (7) to (; 13)

12

It is necessary to be satisfied.

1500 <L <8000 (7)

1

100 <D <2000 (8)

1

2 <L, ≤ 40 (9)

1 1

20 <n <120 Formula (10)

1

5 <D, / d ≤ 30 (1 1)

Formula (12)

[0103] The second continuous multistage distillation column used in step (II) is a length (cm), an inner diameter D

(cm) cylindrical body and internal structure with n steps inside.

: 2 A gas outlet with an inner diameter d (cm) at the top of the tower or near the top of the tower, the bottom of the tower

twenty one

Or a liquid outlet with an inner diameter d (cm) at the bottom of the tower close to it, below the gas outlet

twenty two

One or more fifth inlets at the top and / or middle of the tower, and one or more sixth inlets above the liquid outlet and at the middle and / or bottom of the tower L, D, L / D, n, D / d, D / d force respectively (13) to (1

2 2 2 2 2 2 21 2 22

It is necessary to satisfy 8).

1500 <L <8000 formula (13)

2

100 <D <2000 (14)

2

2 <L / '≤ 40 (15)

twenty two

10 <n <80 Formula (16)

2

2 <D, Zd ≤ 15 (17)

2 21

5 <D, Zd ≤ 30 (18)

[0104] By using the first continuous multi-stage distillation column and the second continuous multi-stage distillation column satisfying all of the formulas (7) to (; 18) at the same time, dialkyl carbonate and aromatic monohydroxy compound can be used. Carbonate on an industrial scale of about 0.85 tons per hour, preferably 1 ton or more, with high selectivity and high productivity, for example 2000 hours or more, preferably 3000 hours or more, more preferably 5000 hours or more It was found that it could be manufactured stably for a long time. The reason why it is possible to produce an aromatic carbonate on an industrial scale having such excellent effects by carrying out the method of the present invention is not clear, but the formulas (7) to (; It is presumed that this is due to the combined effect brought about when the conditions in 18) are combined. The preferred range of each factor constituting the continuous multistage distillation column used in step (II) is shown below.

[0105] If L (cm) and L (cm) are less than 1500 respectively, the reaction rate will decrease and the purpose will be

1 2

In order to reduce the equipment cost while securing the reaction rate that can achieve the target production volume, L and L must be 8000 or less respectively.

1 2

More preferred L (cm) and L (cm) ranges are 2000≤L ≤6000 and

1 2 1

2000≤L≤6000, more preferably 2500≤L≤5000 and 2500

twenty one

≤L≤5000. [0106] If D (cm) and D (cm) are each less than 100, the target production volume can be achieved.

I 2

To reduce equipment costs while achieving the desired output, use D and D

1 2 Each must be 2000 or less.

[0107] The more preferred ranges of D (cm) and D (cm) are 150≤D ≤ 1000 and

1 2 1

t 150≤D ≤1000, more preferably 200≤D ≤800 and 2 respectively

twenty one

00≤D ≤ 800.

2

[0108] In the first continuous multistage distillation column and the second continuous multistage distillation column, D and D

1 2 As long as it is in the above range, the inner diameter may be the same from the upper part to the lower part of the tower, or the inner diameters may be partially different. For example, in these continuous multistage distillation columns, the inner diameter of the upper part of the column may be smaller or larger than the inner diameter of the lower part of the tower.

[0109] Stable operation when L / D and L / D are less than 2 or greater than 40, respectively

I I 2 2

In particular, if the ratio is greater than 40, the pressure difference between the top and bottom of the column becomes too large, and long-term stable operation becomes difficult. This leads to a decrease in selectivity. The more preferred L / Ό and L / Ό ranges are 3≤L / D≤30 and 3≤L / D≤30, respectively.

2 2 1 1 2 2

Preferably, 5≤L / Ό≤15 and 5≤L / Ό≤15.

1 1 2 2

[0110] If the n force is less than ¾0, the reaction rate decreases, so the target production amount in the first continuous multistage distillation column cannot be achieved, and the equipment cost is reduced while ensuring the reaction rate that can achieve the target production amount. In order to lower it, n must be 120 or less. Furthermore, if the n force is greater than 20, the pressure difference between the top and bottom of the column becomes too large, and the long-term stable operation of the first continuous multistage distillation column becomes difficult, and the temperature at the bottom of the column must be increased. Side reactions are likely to occur, leading to a decrease in selectivity. A more preferable range of n is 30≤n≤100, and more preferably 40≤n≤90.

[0111] In addition, since the reaction rate decreases when n force S is less than 10, it is the target in the second continuous multistage distillation column.

2

In order to reduce equipment costs while securing a reaction rate that can achieve the desired production volume, n must be 80 or less. If n is greater than 80

twenty two

Since the pressure difference between the top and bottom of the column becomes too large, the long-term stable operation of the second continuous multistage distillation column becomes difficult, and the temperature at the bottom of the column must be increased. The response tends to occur and the selectivity is lowered. The more preferable range of n is 15≤n≤6

twenty two

0, more preferably 20≤n≤50.

2

[0112] If the D / ά power ^ is smaller, not only the equipment cost of the first continuous multi-stage distillation column is increased, but also a large amount

1 11

Since gas components are likely to go out of the system, stable operation of the first continuous multistage distillation column becomes difficult.

If it is greater than 30, the amount of extracted gas components will be relatively small, resulting in a decrease in reaction rate as well as difficulty in stable operation. The more preferable range of D / ά is 8≤D

≤25, and more preferably 10≤D / ά ≤20. Also from D / ά power ¾

11 1 11 2 21 If it is small, not only will the equipment cost of the second continuous multi-stage distillation column increase, but also a large amount of gas components will easily come out of the system, making stable operation of the second continuous multi-stage distillation column difficult. If the value is larger than that, the amount of extracted gas components becomes relatively small, and the reaction rate is lowered as well as the stable operation becomes difficult. A more preferable range of D / d is 5≤D / d≤12,

2 21 2 21

More preferably, 3≤D / d≤10.

2 21

[0113] If the D / d force is less than ¾, not only will the equipment cost of the first continuous multistage distillation column increase, but also the liquid will be extracted.

1 12

As a result, the amount of water used in the first continuous multi-stage distillation column becomes difficult, and the flow rate is higher than 20 and the flow rate at the liquid discharge port and piping is rapidly increased and erosion is likely to occur. This causes corrosion of the device. A more preferable range of D / ά is 5≤D / ά≤18, and

1 12 1 12

Preferably, 7≤D / d≤15. If the D / d force is less than ¾, the second continuous

1 12 2 22

Not only will the equipment cost of the column distillation column increase, but the amount of liquid extraction will be relatively large, making it difficult to operate the second continuous multi-stage distillation column stably. Becomes rapidly faster and more prone to erosion, leading to equipment corrosion. More preferred D

The range of 2 is 7≤D / d≤25, more preferably 9≤D / d≤20

There are 2 22 2 22

Furthermore, in step (II), the d and the d satisfy the formula (25), and the d and the d satisfy the formula (26).

When 11 12 21 22 was satisfied, it was more preferable.

l≤d / d ≤5 Equation (25)

12 11

l≤d / ά ≤6 Formula (26)

21 22

[0115] The long-term stable operation in the step (II) means 1000 hours or more, preferably 3000 hours or more, more preferably 5000 hours or more, such as flooding, piping clogging or erosion. This means that the operation can be continued in a steady state based on the driving conditions, and a predetermined amount of diaryl carbonate is produced while maintaining a high selectivity.

[0116] The step (II) is characterized by stably producing a gear reel carbonate at a high selectivity for a long period of time with a high productivity of preferably 1 ton or more per hour. Is to produce a gear reel of 2 tons or more per hour, more preferably 3 tons or more per hour. In step (II), L, D, L / D, n, D / d, D / d force S of the first continuous multistage distillation column are 2000≤L≤6000, 150≤D≤1000,

1 1 1 11 1 12 1 1

3≤L / Ό ≤30, 30≤η ≤100, 8≤D / ά ≤25, 5≤D / ά ≤18

1 1 1 1 11 1 12 Therefore, L, D, L / D, n, D / d, D / d of the second continuous multistage distillation column are

2 2 2 2 2 2 21 2 22

2000≤L ≤6000, 150≤D ≤1000, 3≤L / D ≤30, 15≤n ≤60, 2.

2 2 2 2 2

If 5≤D / d≤12, 7≤D / d≤25, more than 2 tons per hour, preferably

2 21 2 22

It is characterized by producing a dial reel carbonate of 2.5 tons or more, more preferably 3 tons or more per hour.

[0117] Furthermore, in step (II), L, D, L / D, n, D / d, D / άS of the first continuous multistage distillation column, 2500≤L≤5000, 200≤D≤800, respectively. , 5≤L / D ≤15,

12 1 1 1 1

40≤n ≤90, 10≤D / d ≤25, 7≤D / d ≤ 15, and second continuous multi-stage steam

1 1 11 1 12

L, D, L / Ό, n, D / d, D / d of the tower are 2500≤L≤5000,

2 2 2 2 2 2 21 2 22 2

200≤D ≤800, 5≤L / Ό ≤10. 20≤η ≤50, 3≤D / ά ≤10, 9≤

2 2 2 2 2 21

If D / d ≤ 20, 3 tons or more per hour, preferably 3.5 tons or more per hour

2 22

More preferably, it is characterized by producing diallyl carbonate of 4 tons or more per hour.

[0118] The selectivity of diaryl carbonate in step (II) refers to the reacted aromatic monohydroxy compound, and in step (II), the selectivity is usually 95% or higher, which is favorable. A high selectivity of preferably 97% or more, more preferably 98% or more can be achieved. Preferably, the first continuous multistage distillation column and the second continuous multistage distillation column used in step (II) are distillation columns having trays and / or packings as internal. In the present invention, the term “rear internal” refers to a portion where the distillation column is actually brought into contact with gas and liquid. As such a tray, those described in the section of step (I) are preferable. In addition, " The number of internal stages n ”is as described above.

[0119] In the first continuous multi-stage distillation column of step (II), a reaction for mainly producing an alkylaryl carbonate from a dialkyl carbonate and an aromatic monohydroxy compound is carried out, but this reaction has an extremely small equilibrium constant. Since the reaction force is slow, it has been found that the first continuous multistage distillation column used for the reaction distillation is preferably an internal column type distillation column. Further, in the second continuous multi-stage distillation column, the reaction force S, in which the reaction for disproportionating the alkylaryl carbonate is mainly performed, and this reaction also has a small equilibrium constant, and the reaction rate is slow. However, as a second continuous multistage distillation column used for reactive distillation, it has been found that an internal distillation column having both a packing and a tray is more preferable. It was also found that the second continuous multistage distillation column is preferably one with a packing at the top and a tray at the bottom. It has also been found that the packing of the second continuous multistage distillation column is particularly preferred among the ordered packings that are preferred for ordered packings.

[0120] Furthermore, the tray installed in each of the first continuous multistage distillation column and the second continuous multistage distillation column has a perforated plate tray having a perforated plate portion and a downcomer portion. It was found to be excellent. It was also found that the perforated plate tray had 100 to 1000 holes per area lm ² of the perforated plate part! /, A force S preferred! /. More preferred! / The number of pores is 120-900 per lm ^{2 of the} area, more preferably 150-800

Yes

[0121] It has also been found that the cross-sectional area per hole of the perforated plate tray is preferably 0.5 to ⁵ cm2. The cross-sectional area per hole is more preferably 0.7 to ⁴ cm ² , and even more preferably 0.9 to ³ cm ² . Further, the perforated plate tray has 100 to 1000 holes per area lm ² of the perforated plate portion, and the cross-sectional area per hole is 0.5 to ⁵ cm ^2. In particular, it has been found to be particularly preferred. It has been found that the object of the present invention can be achieved more easily by adding the above-mentioned conditions to a continuous multistage distillation column.

[0122] When carrying out the step (II), the raw material dialkyl carbonate and the aromatic monohydroxy compound are continuously fed into the first continuous multistage distillation column in which the catalyst is present, and the reaction is carried out in the first column. 1st column low boiling point reaction mixture containing alcohols The product is continuously withdrawn in the form of gas from the upper part of the first column, and the first tower high-boiling point reaction mixture containing the generated alkylaryl carbonates is continuously withdrawn in liquid form from the lower part of the first column, The first column high boiling point reaction mixture is continuously fed into the second continuous multistage distillation column in which the catalyst is present, and the reaction and distillation are simultaneously performed in the second column. A low boiling point reaction mixture is continuously withdrawn in the form of gas from the upper part of the second tower, and a second tower high boiling point reaction mixture containing the generated diaryl carbonate is continuously withdrawn in liquid form from the lower part of the second tower, On the other hand, diaryl carbonate is continuously produced by continuously feeding the second column low boiling point reaction mixture containing dialkyl carbonates into the first continuous multistage distillation column.

[0123] This raw material contains reaction by-products such as alcohols, alkylaryl carbonates, diaryl carbonates, alkylaryl ethers, and high-boiling compounds as reaction products! /, Even! /, Les, as described above. Considering the equipment and cost for separation and purification in other steps, in the case of the present invention which is actually carried out industrially, it is preferable to contain a small amount of these compounds.

[0124] In step (II), in order to continuously supply the raw material dialkyl carbonate and aromatic monohydroxy compound into the first continuous multi-stage distillation column, from the gas outlet at the top of the first distillation column However, it may be supplied in liquid and / or gaseous form from one or several inlets installed in the upper or middle part of the tower, or a raw material rich in aromatic monohydroxy compounds. An inlet that is supplied in liquid form from an inlet at the upper part of the first distillation column and is provided at a lower part of the column at a position higher than the liquid outlet at the lower part of the first distillation column. It is also a preferable method to supply in gaseous form.

[0125] In step (II), the first high-boiling point reaction mixture containing alkylaryl carbonates continuously extracted from the lower part of the first continuous multistage distillation column is continuously supplied to the second continuous multistage distillation column. Although the supply position is lower than the gas outlet at the top of the second distillation column, it is liquid and / or from one or several inlets installed at the top or middle of the column. It is preferable to supply in gaseous form. In the case of using a distillation tower having a packed portion in the upper portion and a tray portion in the lower portion, which is a preferred embodiment of the present invention, at least one of the inlets is installed between the packed portion and the tray portion. Is preferred. Also, If the packing is composed of two or more regular packings, it is also a preferable method to install introduction ports at intervals that constitute these multiple packings.

[0126] Further, in step (II), after condensing the gas components extracted from the top of the first continuous multistage distillation column and the second continuous multistage distillation column, respectively, a part of them is returned to the upper part of each distillation column. Implementing is also a preferred method. In this case, the reflux ratio of the first continuous multistage distillation column is from 0 to 10; the reflux ratio of the second continuous multistage distillation column is from 0.01 to 10; preferably from 0.08 to 5, Preferably, it is in the range of 0.1 to 2. In the first continuous multistage distillation column, a reflux operation is not performed, and a reflux ratio of 0 is also preferred! /.

[0127] In step (II), any method may be used in which the catalyst is present in the first continuous multistage distillation column. However, when the catalyst is in a solid state insoluble in the reaction solution, It is preferable to fix in the tower by a method of installing in a stage in a single continuous multi-stage distillation column or a method of installing in a packed form. Further, in the case of a catalyst that dissolves in the raw material or the reaction solution, it is preferable to supply the catalyst in the position force distillation column above the middle part of the first distillation column. In this case, the catalyst solution dissolved in the raw material or the reaction solution may be introduced together with the raw material, or the catalyst solution may be introduced from an inlet different from the raw material. The amount of catalyst used in the first continuous multi-stage distillation column of the present invention varies depending on the type of catalyst used, the type of raw material and its ratio, reaction temperature, reaction pressure, and other reaction conditions. expressed as a percentage of the total mass, usually 0.000;! ~ 30 mass ^_0/0, preferably <is 0. 0005～; 10 mass ^_0/0, more preferably <is 0. 0 0;! ~ 1 mass Used in%.

[0128] In Step (II), any method may be used for allowing the catalyst to be present in the second continuous multistage distillation column. However, when the catalyst is in a solid state insoluble in the reaction solution, The second continuous multi-stage distillation column is preferably fixed in the column by a method of being installed in a stage or a method of being installed in a packed form. In addition, in the case of a catalyst that dissolves in the raw material or the reaction solution, it is preferable to supply the catalyst in the position force distillation column above the middle part of the second distillation column. In this case, the catalyst solution dissolved in the raw material or the reaction liquid may be introduced together with the raw material, or the catalyst liquid may be introduced from an inlet different from the raw material. The amount of catalyst used in the second continuous multi-stage distillation column of the present invention varies depending on the type of catalyst used, the type of raw material and its ratio, the reaction temperature and the reaction pressure, but the total amount of raw materials. Ratio to mass Expressed in normal 0.000;! ~ 30 mass ^_0/0, preferably <is 0. 0005～; 10 mass ^_0/0, more preferably <is 0. 00; as used to 1 mass%! .

[0129] In step (II), the catalyst used in the first continuous multistage distillation column and the catalyst used in the second continuous multistage distillation column may be the same type or different types. Preferably, it is preferable to use the same type of catalyst. Further preferred are catalysts of the same type that can be dissolved in both reaction solutions. In this case, the catalyst is usually dissolved in the high boiling point reaction mixture of the first continuous multi-stage distillation column, and is extracted from the lower part of the first distillation column together with the alkylaryl carbonate, etc., and is directly used in the second continuous multi-stage distillation column. This is a preferred embodiment. If necessary, a new catalyst can be added to the second continuous multi-stage distillation column.

[0130] The reaction time of the transesterification reaction performed in step (II) is considered to correspond to the average residence time of the respective reaction liquids in the first continuous multistage distillation column and the second continuous multistage distillation column. This differs depending on the internal shape and number of stages of each distillation column, the amount of raw material supply, the type and amount of the catalyst, the reaction conditions, etc., but in each of the first continuous multistage distillation column and the second continuous multistage distillation column. Is usually from 0.01 to 10 hours, preferably from 0.05 to 5 hours, more preferably from 0.;! To 3 hours.

[0131] The reaction temperature of the first continuous multistage distillation column varies depending on the type of raw material compound and the type and amount of the catalyst used, but is usually in the range of 100 to 350 ° C. In order to increase the reaction rate, it is preferable to increase the reaction temperature. However, if the reaction temperature is high, side reactions are liable to occur. For example, by-products such as alkylaryl ethers are increased. In this sense, the preferable reaction temperature in the first continuous multistage distillation column is in the range of 130 to 280 ° C, more preferably 150 to 260 ° C, and still more preferably 180 to 250 ° C.

[0132] The reaction temperature of the second continuous multistage distillation column varies depending on the type of raw material compound and the type and amount of the catalyst used, but is usually in the range of 100 to 350 ° C. In order to increase the reaction rate, it is preferable to increase the reaction temperature. However, if the reaction temperature is high, side reactions are likely to occur. For example, alkyl aryl ethers and alkyl aryl carbonates that are raw materials and products are used. This is not preferable because by-products such as the product of fries rearrangement of diols and carbonates and their derivatives increase. In this sense, the preferred reaction in the second continuous multistage distillation column. Response temperature is 130-280. C, more preferably 150-260. C, more preferably in the range of 180-250 ° C.

[0133] The reaction pressure of the first continuous multistage distillation column varies depending on the type and composition of the raw material compound used, the reaction temperature, and the like. In the first continuous multistage distillation column, the reaction pressure is any of reduced pressure, normal pressure, and increased pressure. Usually, the column top pressure is 0.;! ~ 2 X 10 ⁷ Pa, preferably 10 ⁵ ~; 10 ⁷ Pa, more preferably 2 X 10 ^{5 to} 5 X 10 ⁶ .

[0134] The reaction pressure of the second continuous multi-stage distillation column is different from the force S, the reduced pressure, the normal pressure, and the increased pressure depending on the type and composition of the raw material compound used, the reaction temperature, etc. It is carried out in the range of 0.1 to 2 × 10 ⁷ Pa, preferably 10 ³ to; 10 ⁶ Pa, more preferably 5 × 10 ³ to 10 ⁵ .

[0135] Two or more distillation towers may be used as the first continuous multi-stage distillation tower in the step (II). In this case, two or more distillation columns can be connected in series, connected in parallel, or combined in series and parallel. In addition, two or more distillation towers can be used as the second continuous multistage distillation tower in the step (II). In this case, it is possible to connect two or more distillation columns in series, connect them in parallel, or connect a combination of series and parallel.

[0136] The materials constituting the first continuous multistage distillation column and the second continuous multistage distillation column used in step (II) are mainly metallic materials such as carbon steel, stainless steel, etc. Quality of aromatic carbonate produced From the above aspect, stainless steel is preferred.

[0137] The high boiling point reaction mixture in the second column extracted continuously in liquid form from the bottom of the second continuous multistage distillation column in step (II) is a force mainly composed of diaryl carbonate. It contains alkyl reel carbonate, a small amount of unreacted raw material, a small amount of high-boiling by-products, etc., and when a homogeneous catalyst is used, this catalyst component is also included. Therefore, it is necessary to carry out a purification step (III) for obtaining high-purity diaryl carbonate from the second tower high boiling point reaction mixture. Step (III) may be any method as long as it can obtain high-purity diaryl carbonate from the second tower high boiling point reaction mixture. For example, methods such as distillation and / or recrystallization. Among these, it has been found that in the present invention, it is particularly preferable to perform the step (III) by a distillation method. [0138] Furthermore, in the present invention, step (III) is performed using two distillation towers (a high-boiling substance separation tower, a diaryl carbonate purification tower having a side cut outlet), and the high-boiling substance separation tower. In addition, a column top component mainly composed of unreacted alkylaryl carbonate, a small amount of unreacted raw material and diaryl carbonate, and a column bottom component mainly composed of a small amount of high-boiling by-products and / or a catalyst component. And the top component of the high-boiling-point material separation tower is continuously supplied to the dialyl carbonate purification tower. In the dial reel carbonate purification tower, It has been found that a distillation separation method in which a high-purity diaryl carbonate is obtained as a side-cut component, which is continuously separated into three components, ie, a component and a bottom component, is more preferable.

[0139] Note that the whole or part of the bottom component of the high-boiling-point material separation tower is recycled to the first continuous multistage distillation tower and / or the second continuous multistage distillation tower as the catalyst component in step (II). It is preferable to use it. In addition, since a small amount of diaryl carbonate is usually contained in the tower top component of the diaryl carbonate purification tower, this tower top component is left as it is or a low boiling point component contained in the tower top component is separated. After separation in the distillation column, all or part of the bottom component of the distillation column is returned to the high boiling point separation column and / or the diaryl carbonate purification column to be recovered as high purity diaryl carbonate. Both are preferable methods.

[0140] In the step (III), high-purity diaryl carbonate of usually 99.9% or more, preferably 99.99% or more is obtained. The content of high-boiling by-products is usually 10 ppm or less, preferably 50 ppm or less, and more preferably 10 ppm or less. In addition, since the present invention normally uses a raw material and a catalyst that do not contain halogen, the halogen content of the obtained high-purity diaryl carbonate is 0.1 ppm or less, preferably 10 ppm or less, and more preferably Is less than lppb.

[0141] Subsequently, step (IV) is performed. That is, an aromatic dihydroxy compound is reacted with the high-purity diaryl carbonate to produce a molten prepolymer of an aromatic polycarbonate, and the molten prepolymer is allowed to flow along the surface of the guide, and the molten prepolymer is melted during the flow. This is a process for producing an aromatic polycarbonate using a guide contact flow type polymerization apparatus for polymerizing a prepolymer. [0142] In step (IV), the aromatic dihydroxy compound used is a compound represented by the following general formula.

HO -Ar- OH

(In the formula, Ar represents a divalent aromatic group).

[0143] The divalent aromatic group Ar is preferably represented by the following general formula, for example.

-Ar '-Y-Ar ^2-

(In the formula, Ar ¹ and Ar ² each independently represent a divalent carbocyclic or heterocyclic aromatic group having 5 to 70 carbon atoms, and Y represents a divalent carbocyclic or heterocyclic aromatic group having 1 to 30 carbon atoms. O represents an alkane group)

[0144] In the divalent aromatic group A 1 or Ar ² , one or more hydrogen atoms are not substituted with other substituents that do not adversely influence the reaction, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms, It may be substituted by an aralkoxy group, phenyl group, phenoxy group, vinylol group, cyanol group, ester group, amide group, nitro group or the like having 10 to 10 carbon atoms. Preferable specific examples of the heterocyclic aromatic group include aromatic groups having one or more ring-forming nitrogen atoms, oxygen atoms or sulfur atoms.

Ar ² represents, for example, a group such as substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted pyridylene. The substituents here are as described above.

The divalent alkane group Y is, for example, an organic group represented by the following formula.

[0145] [Chemical 6]

-

[0146] (where

R ⁴ each independently represents hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 10 carbon atoms, a 5- to 10-carbon ring structure; a cycloalkyl group having 10 to 10-carbon atoms. A carbocyclic aromatic group, a C6-C10 carbocyclic aralkyl group; k represents an integer of 3 to 11, R ⁵ and R ⁶ are individually selected for each X, and stand for each other to represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and X represents carbon . R ⁴ , In R ⁵ and R ⁶ , other substituents such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms and an alkyl group having 10 to 10 carbon atoms as long as one or more hydrogen atoms do not adversely influence the reaction. It may be substituted with a silyl group, a phenyl group, a phenoxy group, a bur group, a cyan group, an ester group, an amide group, a nitro group, or the like. )

[0147] Such a divalent aromatic group Ar includes, for example, those represented by the following formulae:

[0148] [Chemical 7]

) _m CH ₃ (R ⁸ ) _n

^

(Wherein R ⁷ and R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 10 carbon atoms; A group having 1 to 10 carbon atoms, an alkoxy group having 10 to 10 carbon atoms, a cycloalkyl group or a phenyl group having 5 to 10 carbon atoms, and m and n are integers of !! to 4 and m is 24 Each R ⁷ may be the same or different! /, And when n is 24, R ⁸ may be the same or different. )

[0149] Furthermore, the divalent aromatic group Ar may be represented by the following formula.

— Ar ¹ — Z— Ar ² —

(In the formula, Ar ¹ and Ar ² are as described above, and Z represents a single bond or a divalent group such as —O— —CO— —S— —SO 2 SO COO CON (R ¹ ) —, where R ¹ is before

2

As described above. )

[0150] Examples of such a divalent aromatic group Ar include those represented by the following formulae:

[0151] [Chemical 8]

s ^

(Wherein R ⁷ , R ⁸ , m and n are as described above.)

Furthermore, specific examples of the divalent aromatic group Ar include substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted pyridylene, and the like.

[0152] The aromatic dihydroxy compound used in the present invention may be a single type or two or more types. A typical example of the aromatic dihydroxy compound is bisphenol A. In the present invention, a trivalent aromatic trihydroxy compound for introducing a branched structure may be used in combination as long as the object of the present invention is not impaired.

[0153] The aromatic dihydroxy compound and high-purity diaryl carbonate in step (IV) The usage ratio (preparation ratio) varies depending on the type of aromatic dihydroxy compound and diaryl carbonate used, the polymerization temperature, and other polymerization conditions, but diaryl carbonate is usually used for 1 mol of aromatic dihydroxy compound. It is used in an amount of 0.9 to 2.5 mol, preferably 0.95 to 2.0 monole, more preferably 0.98 to 1.5 monole.

[0154] In the step (IV), a molten state prepolymer (hereinafter referred to as a molten prepolymer) produced from an aromatic dihydroxy compound and diaryl carbonate is produced from an aromatic dihydroxy compound and diaryl carbonate. It means a melt in the middle of polymerization having a degree of polymerization lower than that of an aromatic polycarbonate having a desired degree of polymerization, and may of course be an oligomer. Such a melted prepolymer used in step (IV) may be obtained by any known method. For example, a molten mixture of a predetermined amount of an aromatic dihydroxy compound and diaryl carbonate is usually used in a temperature range of about 120 ° C. to about 280 ° C. using one or more vertical stirring tanks. It can be produced by removing aromatic monohydroxy compounds by-produced by the reaction while stirring under pressure and / or reduced pressure. A method of continuously producing a melted polymer having a required degree of polymerization by sequentially increasing the degree of polymerization using two or more vertical stirring tanks connected in series is particularly preferable.

[0155] In step (IV), this molten prepolymer is continuously supplied to a guide contact flow type polymerization apparatus to continuously produce an aromatic polycarbonate having a desired degree of polymerization. This guide contact flow type polymerizer is a polymerizer in which a polymer is melted and flowed along a guide, and can produce an aromatic polycarbonate of 1 ton or more per hour.

[0156] The guide contact flow type polymerization reactor is

(1) Molten prepolymer receiving port, perforated plate, polymerized through the perforated plate, the molten prepolymer is supplied to the guide of the reaction zone, surrounded by the perforated plate, the side casing, and the tapered bottom casing. A polymerization reaction zone provided with a plurality of guides extending downward from the perforated plate in the open space, a vacuum vent port provided in the polymerization reaction zone, and an aromatic polycarbonate exhaust provided at the bottom of the tapered bottom casing. An aromatic polycarbonate discharge pump connected to the outlet and the outlet Having

0. 7≤A≤300 Formula (19)

(3) The ratio of the A (m ² ) to the internal cross-sectional area B (m ² ) in the horizontal plane of the aromatic polycarbonate outlet satisfies the formula (20),

20≤A / B≤1000 formula (20)

(4) The tapered bottom case of the polymerization reaction zone is connected to the upper side casing at an angle C degree inside the upper side casing, and the angle C degree satisfies the formula (21). And

120≤C≤165 Formula (21)

(5) The length h (cm) of the guide satisfies the formula (22),

150≤h≤5000 formula (22)

2≤S≤50000 Formula (23)

It is necessary.

[0157] In order to produce high-quality 'high-performance aromatic polycarbonates on an industrial scale with production of 1 ton or more per hour and stable production over a long period without variations in molecular weight, various conditions are satisfied. Therefore, the present invention has been made to find these conditions. In the present invention, “there is no variation in molecular weight” means a variation in number average molecular weight of 200 or less. In the present invention, an aromatic polycarbonate having a number average molecular weight variation of preferably 150 or less, more preferably 100 or less, can be produced stably for a long time.

More specifically, as shown in the conceptual diagram (FIG. 5), the internal cross-sectional area A (m ² ) force S in the horizontal plane (a—a ′ plane) of the side casing 10 in the polymerization reaction zone 5 It is necessary to satisfy the equation (19).

[0159] If A is less than 0.7 m ² , the target production volume cannot be achieved, and in order to achieve this production volume while reducing the equipment cost, A must be 300 m ² or less. It is. [0160] In addition, the ratio of the between A (m ^2), the internal cross-sectional area in the horizontal plane of the aromatic polycarbonate discharge port 7 (b-b 'surface) B (m ²⁾ is, satisfies equation (20) Is also necessary.

[0161] In order to discharge these melts having a high melt viscosity without degrading the quality of the produced aromatic polycarbonate or the aromatic polycarbonate prepolymer having a high degree of polymerization, A / B is expressed by the formula (20) Must be satisfied.

[0162] Further, a tapered bottom casing 11 constituting the bottom of the polymerization reaction zone 5 is provided at an angle C degrees with respect to the upper side casing 10 at an angle C degrees. It is also necessary to satisfy (21).

[0163] In order to reduce the equipment cost, C should be as close to 90 degrees as possible. Force Guide 4 Aromatic polycarbonate falling from the lower end of the guide 4 or aromatic polycarbonate pre-bottle with an increased degree of polymerization In order to move these melts with high melt viscosity to the outlet 7 without degrading the quality of the limer, C must satisfy equation (21).

[0164] Further, it is necessary that the length h (cm) of the guide satisfies the formula (22). When h is shorter than 150 cm, the degree of polymerization of the melted polymer can be increased, but the degree is not sufficient, and the variation in the degree of polymerization becomes about 200 or more in number average molecular weight, which is not preferable. If the h force is longer than S5000cm, the difference in the melt viscosity of the melted prepolymer between the upper and lower parts of the guide becomes too large, so the variation in the degree of polymerization is about 300 or more (in some cases, about 500 or more). This is not preferable because the physical properties of the resulting aromatic polycarbonate vary with increasing size. In the present invention, the large variation in the degree of polymerization means, for example, a variation in which there is a difference of about 200 or more, expressed in terms of number average molecular weight.

[0165] Furthermore, the total external surface area S (m ² ) of the guide 4 needs to satisfy the formula (23).

If S is less than 2m ² , the target production volume cannot be achieved, and in order to achieve this production volume while reducing equipment costs and to eliminate variations in physical properties, S should be 50000m ² or less. is required.

[0166] Surprisingly, there is no coloring and mechanical properties can be improved by using a guide contact flow type polymerization reactor that simultaneously satisfies the equations (19), (20), (21), (22) and (23). Excellent high quality-high High performance aromatic polycarbonate with a production capacity of 1 ton or more per hour can be stably produced without fluctuations in molecular weight for a long period of several hundred hours or more, for example, 5,000 hours or more. Was found. If these conditions are not satisfied at the same time, the target production volume cannot be obtained, the molecular weight variation is expressed in terms of number average molecular weight, and there is a variation with a difference of about 200 or more. Inconveniences such as inability to color for 1,000 hours and faint coloring.

[0167] In Step (IV), it is not clear why it is possible to produce an aromatic polycarbonate having such excellent effects on an industrial scale, but in addition to the above reasons, This is presumed to be due to the combined effects that appear when conditions are combined. For example, by using a high surface area guide that satisfies formulas (22) and (23), the molten prepolymer can be polymerized at a relatively low temperature, and a large amount of high-quality aromatic polycarbonate having the desired molecular weight can be produced. The taper-shaped bottom casing that satisfies formula (21) can reduce the time it takes for this large quantity of high quality product aromatic polycarbonate falling from the guide to reach the outlet, As a result, it is presumed that the thermal history of the produced aromatic polycarbonate can be reduced.

[0168] It should be noted that such manufacturing technology on an industrial scale can only be established for a long time using large-scale manufacturing equipment. Manufacturing equipment costs at that time are an important factor to consider. There is nothing to wait for. Another effect of the present invention is that the polymerization reactor used in step (IV) is a guide contact flow type polymerization reactor satisfying the equations (19), (20), (21), (22) and (23). Therefore, the facility cost can be reduced as an industrial production facility.

[0169] The range required for the size, angle, and the like in the guide contact flow type polymerization reactor used in step (IV) is as described above, and more preferable ranges are as follows. A more preferable range of the internal cross-sectional area A (m ² ) in the horizontal plane of the side casing of the polymerization reaction zone is 0.8≤A≤250, more preferably 1≤A≤200.

[0170] Further, the A (m ² ) and the internal cross-sectional area B in the horizontal plane of the aromatic polycarbonate outlet

A more preferable range of the ratio to (m ² ) is 25≤A / B≤900, and more preferably 30≤A / B≤800. [0171] Further, the more preferable range of the angle C degrees formed inside the tapered bottom casing constituting the bottom of the polymerization reaction zone with respect to the upper side casing is 125 ≤ C ≤ 160, and more preferably Is 135≤C≤165. In addition, when increasing the polymerization degree sequentially using multiple guided contact flow type polymerization reactors, if the corresponding angles are Cl, C2, C3, ..., C1≤C2≤C3 ≤ ... is preferable

Yes

[0172] Further, the required length h (cm) of the guide depends on factors such as the degree of polymerization of the raw material prepolymer, the polymerization temperature and pressure, the degree of polymerization of the aromatic polycarbonate or prepolymer to be produced in the polymerization vessel, and the production amount. More preferred range of forces depending on the difference is 200≤h≤3000, more preferably 250≤h≤2500. It is particularly preferable when h satisfies the formula (31).

400 <h≤2500 Formula (31)

[0173] The total external surface area S (m ² ) of the entire guide required also varies depending on the same factors as above. The more preferable range is 4≤S≤40000, more preferably 10≤S ≤ 30000. 15≤S≤ 20000 °, the preferred range. The external total surface area of the entire guide referred to in the present invention means the entire surface area of the guide that flows down in contact with the molten polymer. For example, in the case of a guide such as a pipe, it means the outer surface area. The surface area of the inner surface of the pipe that does not allow the prepolymer to flow down is not included.

[0174] In the guide contact flow type polymerization reactor used in the step (IV), the shape of the internal cross section in the horizontal plane of the side casing of the polymerization reaction zone may be any shape such as a polygon, an ellipse, and a circle. . Since the polymerization reaction zone is usually operated under reduced pressure, it may be of any type as long as it can withstand it, but preferably it is circular or has a shape close to it. Therefore, the side casing of the polymerization reaction zone of the present invention is preferably cylindrical. In this case, it is preferable that a tapered bottom casing is connected to the lower part of the cylindrical side casing, and a cylindrical aromatic polycarbonate discharge port is provided at the lowermost part of the bottom casing. When the inner diameter of the cylindrical portion of the side casing is D (cm), the length is L (cm), and the inner diameter of the discharge port is d (cm), D, L, and d are expressed by the formula (27) (28), (29) and (30) are preferably satisfied. 100≤D≤1800 formula (27)

5≤D / d≤50 formula (28)

0. 5≤L / D ≤30 (29)

h-20 ≤ L ≤ h + 300 formula (30)

[0175] In the guide contact flow type polymerization reactor, a more preferable range of D (cm) is 150≤D≤1500, and more preferably 200≤D≤1200. Further, a more preferable range of D / d is 6≤D / d≤45, and more preferably 7≤D / d≤40. Further, a more preferable range of L / D is 0.6≤L / D≤25, and more preferably 0.7≤L / D≤20. Further, a more preferable range of L (cm) is h—10≤L≤h + 250, and more preferably h≤L≤h + 200. If D, d, L, and h do not satisfy these relationships at the same time, it is difficult to achieve the object of the present invention.

[0176] In process (IV), a high-quality, high-performance aromatic polycarbonate with high polymerization rate, no coloration, and excellent mechanical properties is produced stably on an industrial scale with no molecular weight variation over a long period of time. The exact reason for this is not clear, but the following are possible. In other words, in the guide contact flow polymerization method in step (IV), the molten precursor polymer is guided from the receiving port 1 to the guide 4 via the supply zone 3 and the perforated plate 2, and along the guide. The degree of polymerization increases while flowing down. In this case, the molten prepolymers are effectively agitated and renewed while flowing down along the guide, and phenol and the like are extracted effectively, so that the polymerization proceeds at a high speed. As the polymerization progresses, the melt viscosity increases, so that the adhesive strength to the guide increases, and the amount of the melt sticking to the guide increases as it goes to the bottom of the guide. This means that the residence time of the molten prepolymer on the guide, that is, the polymerization reaction time is increased. In addition, the melted polymer that flows down under its own weight while being supported by the guide has a very large surface area per mass, and its surface is renewed efficiently. The high molecular weight in the latter half of the polymerization, which was possible, can be easily achieved. This is one of the excellent features of the polymerization vessel used in step (IV).

[0177] In the second half of the polymerization below the middle part of the guide, the amount of the melt sticking to the guide increases S, and since there is only an adhesive holding force commensurate with the melt viscosity, the same height of the multiple guides In, the same amount of melt force with almost the same melt viscosity is supported by each guide. On the other hand, since the melt is continuously supplied from the top to the guide, the melt having a high degree of polymerization having substantially the same melt viscosity continuously falls from the lower end of the guide to the taper-shaped bottom casing. Will go. In other words, at the bottom of the tapered bottom casing, aromatic polycarbonate having almost the same degree of polymerization produced while flowing down the guide accumulates, and it is possible to continuously produce aromatic polycarbonate with no variation in molecular weight. become. This is one of the other excellent features of the polymerizer of the present invention. Aromatic polycarbonate accumulated at the bottom of the tapered bottom casing is continuously withdrawn by the discharge pump 8 through the discharge port 7, and is normally pelletized continuously through an extruder. In this case, additives such as stabilizers and weathering agents can be added by an extruder.

[0178] The perforated plate constituting the guided contact flow type polymerization reactor used in step (IV) is usually selected from a flat plate, a corrugated plate, a plate with a thick central portion, etc. A shape force such as circular, oval, triangular or polygonal is selected. The holes of the perforated plate are usually selected from shapes such as a circle, an ellipse, a triangle, a slit, a polygon, and a star. The cross-sectional area of the hole is usually from 0.01 to 100 cm ² , preferably from 0.05 to 10 cm ² , particularly preferably from 0.;! To 5 cm ² . The distance between the holes is usually 1 to 500 mm, preferably 25 to 100 mm, based on the distance between the centers of the holes. The hole in the perforated plate may be a hole penetrating the perforated plate or may be a case where a tube is attached to the perforated plate. Further, it may be tapered.

[0179] Further, the guide constituting the guide contact flow type polymerization reactor used in the step (IV) has a very high ratio of the length in the vertical direction to the average length of the outer periphery of the horizontal cross section. It represents a large material. The ratio is usually in the range of 10-; 1,000,000, preferably 50-; 100,000. The shape of the cross section in the horizontal direction is usually selected from shapes such as a circle, an ellipse, a triangle, a quadrangle, a polygon, and a star. The shape of the cross section may be the same or different in the length direction. The guide may be hollow.

[0180] The guide has no wire or thin rod, and the melted prepolymer does not enter inside. A single one such as a thin pipe-like one may be used, or a plurality of such may be combined by a method such as twisting. Further, a net-like one or a punching plate-like one may be used. The surface of the guide may be smooth or uneven, or may have a projection or the like partially. A preferable guide is a cylindrical shape such as a wire shape or a thin rod shape, a net shape such as the above-mentioned thin pipe shape, or a punching plate shape.

[0181] The guide itself may have a heat source such as an electric heater or a heat source inside the guide. 持た A guide that does not have a heat source has no concern about thermal denaturation of the prepolymer or aromatic polycarbonate on its surface. , So especially preferred.

[0182] In the guided contact flow type polymerizer of the present invention that enables production of high-quality aromatic polycarbonate on an industrial scale (production amount, long-term stable production, etc.), it is particularly preferable to use a plurality of wires. / Or rod-shaped or the above-mentioned narrow! /, A guide of the type of pipe that connects the guides at appropriate intervals above and below using a horizontal support material from the top to the bottom of the pipe-shaped guide. is there. For example, a plurality of wire-like or thin rod-like or wire-like nets fixed at appropriate intervals above and below, for example, lcm to 200 cm, using a horizontal support material from the top to the bottom of the thin pipe-shaped guide. A guide, a three-dimensional guide in which a plurality of wire mesh guides are arranged at the front and back, and they are joined at a suitable distance above and below using a lateral support material, for example, a distance of lc m to 200 cm, or a plurality of wires A jungle-gym standing body that is fixed at appropriate intervals above and below, for example, 1 cm to 200 cm, using horizontal support materials on the front and back, left and right of the rod-shaped or thin pipe-shaped guide. Guide. The support material in the horizontal direction not only helps to keep the distance between the guides approximately the same, but also helps to strengthen the guides that are flat or curved as a whole or three-dimensional guides. These supporting materials may be the same material as the guide, or may be different.

[0183] In a guide contact flow type polymerization reactor, when one guide is a cylindrical shape having an outer diameter r (cm) or a pipe shape in which a molten prepolymer is not allowed to enter, r is represented by the formula (3 2 ) Satisfied! /, Preferable to!

0. l≤r≤l Equation (32) [0184] This guide advances the polymerization reaction while flowing the molten prepolymer, but also has a function of holding the molten prepolymer for a certain period of time. This holding time is related to the polymerization reaction time, and as described above, the holding time and the holding amount increase as the melt viscosity increases as the polymerization proceeds. The amount that the guide retains the melted prepolymer varies depending on the external surface area of the guide, that is, in the case of a cylindrical shape or a pipe shape, even if the melt viscosity is the same.

[0185] In addition to the weight of the guide itself, the guide installed in the polymerization vessel of the present invention needs to be strong enough to hold and support the weight of the molten prepolymer. In this sense, the thickness of the guide is important. In the case of a columnar shape or a pipe shape, it is preferable that the formula (32) is satisfied. If r is less than 0.1, it will be difficult to perform stable operation for a long time in terms of strength. When r is larger than 1, the guide itself becomes very heavy, and the melted prepolymer has only the inconvenience, for example, the thickness of the perforated plate has to be very thick in order to hold them in the polymerizer. There are inconveniences such as an increase in the portion where the amount of retention increases too much and the variation in molecular weight increases. In this sense, the more preferred range of r is 0.15≤r≤0.8, and even more preferred is 0.2≤r≤0.6.

[0186] A preferable material for such a guide is selected from metals such as stainless steel, carbon steel, hastelloy, nickel, titanium, chromium, aluminum and other alloys, and a polymer material having high heat resistance. Particularly preferred is stainless steel. The surface of the guide may be subjected to various treatments such as plating, lining, passivation treatment, acid washing, and phenol washing as necessary.

[0187] The positional relationship between the guide and the perforated plate and the positional relationship between the guide and the hole in the perforated plate are not particularly limited as long as the molten polymer pre-guide flow is possible! /, . The guide and the perforated plate may or may not be in contact with each other. The guide is preferably installed in correspondence with the holes of the perforated plate, but is not limited thereto. This is because the molten pre-bolimer falling from the perforated plate may be designed to come into contact with the guide at an appropriate position. As a preferable specific example of installing the guide in correspondence with the hole of the perforated plate, (1) The upper end of the guide is fixed to the upper inner wall surface of the polymerization vessel, etc. (2) A method in which the upper end of the guide is fixed to the peripheral edge of the upper end of the hole in the perforated plate and the guide is provided in a state in which the guide passes through the hole in the perforated plate. And (3) a method of fixing the upper end of the guide to the lower surface of the perforated plate.

[0188] As a method of flowing down the molten prepolymer through the perforated plate along the guide, a method of flowing down with a liquid head or its own weight, or by pressurizing with a pump or the like, the perforated plate force is also reduced. A method such as extrusion is exemplified. It is preferable to supply a predetermined amount of the raw molten polymer to the polymerizer supply zone under pressure using a supply pump, and the molten polymer delivered to the guide through the perforated plate flows down along the guide under its own weight. It is a method. The molten prepolymer is usually continuously supplied to the guide contact flow type polymerization reactor while being heated to a predetermined polymerization temperature. Therefore, it is preferable that a jacket or the like is usually provided on the outer wall surface of the guide contact flow type polymerization reactor, and it is preferable to heat the jacket to a predetermined temperature through a heating medium or the like. Accordingly, it is preferable to heat / preheat the molten prepolymer, the prepolymer supply zone and the perforated plate, and heat the polymerization reaction zone, the side casing, and the tapered bottom casing.

[0189] In the step (IV), the temperature of the reaction for producing an aromatic polycarbonate by polymerizing a molten polymer obtained from an aromatic dihydroxy compound and diaryl carbonate in a guide contact flow type polymerization reactor is usually It is in the range of 80-350 ° C. However, in the polymerization apparatus of the present invention, since efficient surface renewal with internal stirring is performed, the polymerization reaction can proceed at a relatively low temperature. Therefore, the preferred reaction temperature is 100 to 290 ° C, and more preferred is 150 to 270 ° C. In conventional reactors for horizontal biaxial stirring type ultra-high viscosity polymers, it was necessary to stir for a long time under a high vacuum of 133 Pa or less, usually at a high temperature of 300 ° C or higher. In addition, yellowing due to air leakage from the stirring shaft seal and contamination with foreign matter were not avoided. Since the polymerizer of the present invention does not have mechanical stirring, there is no seal portion of the stirrer, so that leakage of air or the like is very small. Moreover, it is a feature of the present invention that the polymerization can proceed sufficiently at a temperature as low as about 20 to 50 ° C. as compared with a conventional reactor for a horizontal biaxial stirring type ultrahigh viscosity polymer. This also means that the present invention produces a high-quality aromatic polycarbonate with no coloring or deterioration of physical properties. It is a big cause that can be.

[0190] In addition, it is impossible to produce an aromatic polycarbonate having a medium viscosity grade or higher even with a conventional horizontal biaxially stirred ultrahigh viscosity polymer reactor because of its ultrahigh viscosity. In the guide contact flow type polymerization apparatus of the present invention, high viscosity grade aromatic polycarbonate can be easily produced. In other words, the guide contact flow type mixer of the present invention can produce all grades of aromatic polycarbonate from a disk grade having a relatively low molecular weight to a high viscosity grade. This is also a major feature of the present invention.

[0191] In step (IV), an aromatic monohydroxy compound is produced as the polymerization reaction proceeds, and the reaction rate can be increased by removing this from the reaction system. Therefore, an inert gas that does not adversely influence the reaction, such as nitrogen, argon, helium, carbon dioxide, or lower hydrocarbon gas, is introduced into the polymerization reactor, and the aromatic monohydroxy compounds that are produced are introduced into these gases. For example, a method in which the reaction is carried out together with the solvent and a method in which the reaction is carried out under reduced pressure are preferably used. Alternatively, a method in which these are used in combination is also a force that can be preferably used. In these cases, it is not necessary to introduce a large amount of inert gas into the polymerization vessel, and the inside may be maintained in an inert gas atmosphere.

[0192] It is also a preferred method to absorb the inert gas and polymerize the inert gas-absorbing molten prepolymer in the next step / before the molten prepolymer is supplied to the guide contact flow type polymerization reactor. .

[0193] The preferable reaction pressure in the polymerization vessel in the step (IV) varies depending on the type of aromatic polycarbonate to be produced, the molecular weight, the polymerization temperature, etc. For example, from a molten polymer from bisphenol A and diphenyl carbonate to an aromatic In the case of producing polycarbonate, when the number average molecular weight is 5,000 or less, 400 to 3, OOOPa range force S is preferable, and when the number average molecular weight is 5,000 to 10,000, the range is 50 to 500 Pa. preferable. When the number average molecular weight is 10,000 or more, 300 Pa or less is preferable, and a range force of 20 to 250 Pa is preferably used.

[0194] In carrying out step (IV), it is possible to produce an aromatic polycarbonate having the desired degree of polymerization with only one guided contact flow type polymerizer, but it is possible to produce a solution as a raw material. Depending on the degree of polymerization of the melted prepolymer and the amount of aromatic polycarbonate produced, it is preferable to connect two or more guide contact flow type polymerizers and increase the degree of polymerization in order. In this case, each polymerizer is a preferred method because guides and reaction conditions suitable for the degree of polymerization of the prepolymer or aromatic polycarbonate to be produced can be adopted separately. For example, use a guide contact flow type first polymerization device, a guide contact flow type second polymerization device, a guide contact flow type third polymerization device, and a guide contact flow type fourth polymerization device. In the case of the increasing method, if the external total surface area of the entire guide of each polymerizer is Sl, S2, S3, S4— ', the force S can be obtained as S1≥S2≥S3≥S4≥'—. Further, the polymerization temperature may be the same in each polymerization vessel, or may be raised in order. The polymerization pressure can also be lowered in each polymerization vessel in turn.

[0195] In this sense, for example, when the polymerization degree is increased in this order using two polymerizers, a guide contact flow type first polymerization vessel and a guide contact flow type second polymerization vessel, the first It is preferable to use a guide in which the external total surface area SI (m ² ) of the entire guide of the polymerization vessel and the external total surface area S2 (m ² ) of the overall guide of the second polymerization vessel satisfy the formula (33). .

1≤S1 / S2≤20 Formula (33)

[0196] If S1 / S2 is less than 1, there will be inconveniences such as large variations in molecular weight, making stable production difficult for a long period of time, and difficulty in obtaining a predetermined production amount. S 1 / S2 is more than 20 If it is large, the flow rate of the molten polymer that flows down the guide in the second polymerization vessel increases, and as a result, the residence time of the molten polymer is reduced and the aromatic polycarbonate having the required molecular weight can be obtained. Inconvenience occurs. In this sense, it is a more preferable range (or 1.5≤S 1 / S2≤15.

[0197] In step (IV), 1 ton or more of aromatic polycarbonate is produced per hour, but since the aromatic monohydroxy compound by-produced by the polymerization reaction is discharged out of the system, More than 1 ton of molten prepolymer polymerizer needs to be fed. Therefore, the amount of melted polymer to be supplied varies depending on the degree of polymerization and the degree of polymerization of the aromatic polycarbonate to be produced, but it is usually 10-500 kg / per 1 ton / hr of aromatic polycarbonate production. hr more, 1. 01 ~; 1.5 in the range of 5 tons / hr is there.

The reaction for producing an aromatic polycarbonate from an aromatic dihydroxy compound and diaryl carbonate in step (IV) can be carried out without adding a catalyst. In order to increase the polymerization rate, in the presence of a catalyst, if necessary. Done. The catalyst is not particularly limited as long as it is used in this field, but alkali metal and alkaline earth metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide are used. ; Alkali metal salts, alkaline earth metal salts, quaternary ammonium salts of hydrides of boron and aluminum such as lithium aluminum hydride, sodium borohydride, tetramethylammonium borohydride; lithium hydride, sodium hydride, hydrogen Hydrogenation of alkali metals and alkaline earth metals such as russia; alkali metals and alkaline earth metal alkoxides such as lithium methoxide, sodium ethoxide and calcium methoxide; lithium phenoxide, sodium phenoxide Cid, magnesium phenoxy Alkali metal and alkaline earth metal alkoxides such as LiO—Ar—OLi and NaO—Ar—ONa (Ar is aryl); Alkali metals and alkaline earth such as lithium acetate, calcium acetate and sodium benzoate Organic acid salts of metals, zinc compounds such as zinc oxide, zinc acetate, zinc phenoxide; boron oxide, boric acid, sodium borate, trimethyl borate, tributyl borate, triphenolate borate, (R ^ E ^ RR ^ NB O ^ I ^ RR ⁴ ) or (I ^ I ^ RR ⁴ ) PB (R'R'R'R ⁴ ) Ammonium borates or phosphoneumborates

R ⁴ is as described in the above formula. Boron compounds such as) oxides; sodium oxides, sodium silicates, tetraalkyl cages, tetraaryl cages, diphenylethyl ethoxy ketones; germanium oxides, tetrachlorides Genolenium compounds such as genoremanium, genoremanium ethoxide, genoremanium phenoxide; alkoxy groups such as tin oxide, dialkyltin oxide, dialkyltin carboxylate, tin acetate, ethyltin tributoxide Or tin compounds bonded to aryloxy groups, tin compounds such as organic tin compounds; lead oxides such as lead oxide, lead acetate, lead carbonate, basic carbonates, lead and organic lead alkoxides, Compound: Onium compound such as quaternary ammonium salt, quaternary phosphonium salt, quaternary arsonium salt, etc. Antimony compounds such as antimony oxide and antimony acetate; Manganese compounds such as manganese acetate, manganese carbonate, and manganese borate; titanium compounds such as titanium oxide, alkoxide of titanium, and aryl-toxide; zirconium acetate, zirconium oxide, alkoxide or aryloxide of zirconium, Catalysts such as zirconium compounds such as zirconium acetylacetone can be mentioned.

Yes

[0199] When a catalyst is used, these catalysts may be used alone or in combination of two or more. The amount of these catalysts, the aromatic dihydroxy compound of the raw materials, usually 10_ ^{1 ()} to 1 wt%, preferably from 10_ ⁹ ~; ^ mass. /. , Rather more preferably is 10 ⁸ ~; selected at 10- ^2% by weight range. In the case of the melt transesterification method, the polymerization catalyst used is the force remaining in the aromatic polycarbonate of the product. These polymerization catalysts usually have an adverse effect on the physical properties of the polymer. Therefore, it is preferable to reduce the amount of catalyst used as much as possible. In the method of the present invention, since the polymerization can be performed efficiently, the amount of the catalyst used can be reduced. This is another feature of the present invention that enables the production of high-quality aromatic polycarbonate.

[0200] There are no particular restrictions on the material of the guide contact flow type polymerizer and piping used in step (IV). Usually stainless steel, carbon steel, hastelloy, nickel, titanium, chromium, and other alloys Metals such as manufactured products and medium heat resistant polymer materials are selected. In addition, the surface of these materials may be subjected to various treatments such as plating, lining, passivation treatment, pickling, and phenol washing as necessary. Particularly preferred are stainless steel, nickel, glass lining and the like.

[0201] A large amount of aromatic monohydroxy compound by-produced by the reaction is usually continuously extracted in the form of a gas during the production of the prepolymer in step (IV) and the polymerization in the guide contact flow type polymerization reactor. It is condensed into a liquid and recovered. In the present invention, it is necessary to perform the aromatic monohydroxy compound recycling step (V) in which the aromatic monohydroxy compound by-produced in step (IV) is circulated to the diaryl carbonate production step (II). . In the industrial production method, it is important to recover the entire amount of aromatic monohydroxy compounds by-produced with as little loss as possible and to circulate and reuse them. The by-product aromatic monohydroxy compound by-produced and recovered in step (IV) of the present invention usually contains diaryl carbonate. Although it is partially contained, it can be recycled and reused in the diaryl carbonate production process (II) as it is because of its high purity. In addition, when a small amount of aromatic dihydroxy compound or a small amount of oligomer is mixed in the recovered aromatic monohydroxy compound, further distillation is performed to remove these high-boiling substances, It is preferable to circulate and reuse in the carbonate production process (II).

The aromatic polycarbonate produced by carrying out the system of the present invention has a repeating unit represented by the following chemical formula 9.

[0202]

[0203] (In the formula, Ar is the same as described above.)

Particularly preferred is an aromatic polycarbonate containing 85 mol% or more of a repeating unit represented by the following chemical formula 10 among all repeating units.

[0204] [Chemical 10]

[0205] Further, the terminal group of the aromatic polycarbonate produced by carrying out the method of the present invention is usually composed of a hydroxy group or an aryl carbonate group represented by the following formula.

[0206] [Chemical 11]

0 C 0 A r ⁵

(In the formula, Ar ⁵ is the same as Ar ³ and Ar ⁴ described above.) The ratio of hydroxy group to aryl carbonate group is not particularly limited, but is usually in the range of 95: 5 to 5:95, preferably in the range of 90:10 to 10:90, and more preferably in the range of 80:20 to The range is 20:80. Particularly preferred is an aromatic polycarbonate in which the proportion of the phenyl carbonate group in the terminal group is 60 mol% or more.

[0208] The aromatic polycarbonate produced by carrying out the method of the present invention may be partially branched with respect to the main chain via a hetero bond such as an ester bond or an ether bond. The amount of the heterologous binding to carbonate bonds is usually 0.005 to 2 mol%, good Mashiku is 0. 01 ;! Monore ^_0/0, a, more preferred, 0.05 -0. 5 Monore is ^_0/0. This amount of dissimilar bonds improves flow characteristics during melt molding without deteriorating other polymer properties, making it suitable for precision molding and molding with relatively low temperature and excellent performance. Can be manufactured. The molding cycle can be shortened, contributing to energy saving during molding.

[0209] The aromatic polycarbonate produced by carrying out the method of the present invention contains almost no impurities, but an alkali metal and / or alkaline earth metal is used as the metal element. An aromatic polycarbonate containing! ~ Lppm can be produced. Preferably (this content power is 0.005-0.5 ppm, more preferably (0.01-0.1 ppm). Such a metal element is 1 ppm or less, preferably 0.5 ppm or less, more preferably In the case of 0. lp pm, since the physical properties of the product aromatic polycarbonate are not adversely affected, the aromatic polycarbonate produced in the present invention is of high quality.

[0210] Among the aromatic polycarbonates produced by carrying out the method of the present invention, particularly preferred are those produced by using a halogen-free aromatic dihydroxy compound and diaryl carbonate, The halogen content is usually less than lOppb. According to the method of the present invention, those having a halogen content of 5 ppb or less can be produced, and more preferably, aromatic polycarbonates having a halogen content of 1 ppb or less can be produced, resulting in a very high quality product. It will be.

[0211] It is clear from the examples that the method of the present invention can stably produce an aromatic polycarbonate having no variation in molecular weight for a long time because a specific polymerization vessel is used. Example

[0212] Hereinafter, the present invention will be described more specifically by way of examples. The present invention is not limited to the following examples.

'Number average molecular weight (Mn): Measured by gel permeation chromatography (GPC) method using tetrahydrofuran as a carrier solvent, and calculated using the converted molecular weight calibration curve of the following formula obtained using standard monodisperse polystyrene. Average molecular weight (Mn) was determined.

M = 0. 3591M ⁰³⁸⁸

PC PS

(Where M is the molecular weight of the aromatic polycarbonate and M is the molecular weight of polystyrene.

PC PS

The )

• Color: Using an injection molding machine, aromatic polycarbonate was continuously molded with a cylinder temperature of 290 ° C and a mold temperature of 90 ° C, 50mm long x 50mm wide x 3.2mm thick. The color tone of the obtained specimen was measured by the CIELAB method (Commission Internationale de l'Eclairage 1976 Lab Diagram), and the yellowness was indicated by b * value.

• Tensile elongation: An injection molding machine was used, and an aromatic polycarbonate was injection molded at a cylinder temperature of 290 ° C and a mold temperature of 90 ° C. The tensile elongation (%) of the obtained specimen having a thickness of 3.2 mm was measured according to ASTM D638.

• The amount of heterogeneous bonds was measured by the method described in W097 / 32916, alkali metal / alkaline earth metal was measured by ICP method, and halogen was measured by ion chromatography method.

Yes

[0213] [Example 1]

(1) Process for continuously producing dimethyl carbonate and ethylene dalycol (I) <Continuous multistage distillation column T>

0

L = 3300cm, D = 300cm, L / Ό = 1 1, η = 60, D / ά as shown in Figure 1

0 0 0 0 0 0 0

A continuous multistage distillation column with = 7.5, D / ά = 12 was used. In this embodiment,

1 0 02

As the internal plate, a perforated plate tray having a cross-sectional area per hole in the perforated plate portion = about 1.3 cm ² and the number of holes = about 180 to 320 holes / m ² was used.

Liquid ethylene carbonate 3. 27 tons / hr is installed at the 55th level from the bottom (inlet ( It was continuously introduced into the distillation column T from 3—a). Gaseous methanol (dimethyl carbonate

0

Over preparative containing 8.96 mass ^_0/0) 3.238 t / hr and a liquid methanol (containing dimethyl carbonate 6.66 wt%) 7.489 t / hr was placed on 31 stage from the bottom It was continuously introduced into the distillation column T from the inlets (3-b and 3-c). Of raw materials introduced into the distillation column T

0 0

The monore ratio was methanol / ethylene carbonate = 8.36.

The catalyst is ◯ ^ 1 (48% by weight aqueous solution) 2. Add 4.8 tons of ethylene glycol to 5 tons, heat to about 130 ° C, gradually reduce the pressure, and heat-treat at about 1300 Pa for about 3 hours, and uniform The solution was used. This catalyst solution was continuously introduced into the distillation column T from the inlet (3-e) provided at the 54th stage from the bottom (K concentration: 0.1 with respect to the supplied ethylene carbonate).

0

mass%). Reactive distillation was carried out continuously under the conditions that the temperature at the bottom of the column was 98 ° C., the pressure at the top of the column was about 1.118 × 10 ⁵ Pa, and the reflux ratio was 0.42.

[0214] Stable steady operation was achieved after 24 hours. The low boiling point reaction mixture withdrawn in the form of gas from the top 1 of the column was cooled with a heat exchanger to be liquid. The dimethyl carbonate in the liquid low boiling point reaction mixture continuously withdrawn from the distillation column at 10.678 tons / hr was 4.129 // hr and methanol was 6. 549 // hr. In the liquid continuously extracted at 3.382 卜 / hr, ethylene glycol is 2. 356 tons / hr and methanol is 1.014 tons / hr, unreacted ethylene. The carbonate was 4 kg / hr. Excluding dimethyl carbonate contained in the raw material, the actual production amount of dimethyl carbonate per hour was 3.340 tons, and excluding ethylene glycol contained in the catalyst solution, the actual production amount of ethylene glycol per hour was 2. It was 301 tons. The reaction rate of ethylene carbonate was 99.88%, the selectivity of dimethyl carbonate was 99.99% or more, and the selectivity of ethylene glycol was 99.99% or more.

[0215] Under these conditions, long-term continuous operation was performed. After 500 hours, 2000 hours, 4000 hours, 5000 hours, 6000 hours, the actual production amount per hour is dimethyl carbonate power 3.340 、, 3.340 、, 3.340 、, 3. 340 tons, 3. 340 tons, m chilling force Nore force 2. 301 tons, 2. 301 tons, 2. 301 tons, 2. 301 tons, 2. 301 tons, the reaction rate of ethylene carbonate 99.90%, 99.89%, 99.89%, 99.88%, 99.88%, and the selectivity of dimethyl carbonate is 99.99% or more, 99.99% or more, 99.99% Less than 99.99% or more, 99.99% or more, ethylene glycol selectivity is 99.99% or more, 99.99% or more, 99.99% or more, 99.99% or more, 99.99% That was all.

[0216] (2) Step of continuously producing diphenyl carbonate (II)

As shown in FIG. 2, a continuous multistage distillation column having L = 3300 cm, D = 500 cm, L / Ό = 6.6, η = 80, D / d = 17, D / d = 9 was used. In this embodiment,

11 1 12

As the internal plate, a perforated plate tray having a cross-sectional area per hole = about 1.5 cm ² and the number of holes = about 250 holes / m ² was used.

L = 3100cm, D = 500cm, L / Ό = 6.2, η = 30, D / as shown in Figure 3

A continuous multi-stage distillation column with 2 2 2 2 2 2 d = 3.85 and D / d = 11.1 was used. This example

21 2 22

With the, as internal, upper portion placed Mellapak 2 group (the total number of theoretical plates 11 stages), the cross-sectional area = about 1. 3 cm ² per one hole at the bottom, the number of holes of approximately 250 / m ² A perforated plate tray was used.

[0217] <Reactive distillation>

Diphenyl carbonate was produced by reactive distillation using an apparatus in which the first continuous multistage distillation column 101 and the second continuous multistage distillation column 201 were connected as shown in FIG.

Raw material 1 consisting of phenol / dimethyl carbonate = 1.9 (weight ratio) was continuously introduced in liquid form from the upper inlet 11 of the first continuous multistage distillation column 101 at a flow rate of 50 ton / hr. On the other hand, the raw material 2 consisting of dimethyl carbonate / phenol = 3.6 (weight ratio) was continuously introduced in a gaseous state from the lower inlet 12 of the first continuous multi-stage distillation column 101 at a flow rate of 50 tons / hr. The molar ratio of the raw materials introduced into the first continuous multistage distillation column 101 was dimethyl carbonate / phenol = 1.35. This raw material was substantially free of halogen (outside the limit of detection by ion chromatography, lppb or less). The catalyst is Pb (OPh)

2 It was introduced from the upper inlet 11 of the first continuous multi-stage distillation column 101 so that the reaction solution was about lOOppm. In the first continuous multistage distillation column 101, the temperature at the bottom of the column was 225 ° C, and the reactive distillation was performed continuously under the conditions of the pressure at the top of the column S7 X 10 ⁵ Pa. The first tower low boiling point reaction mixture containing methyl alcohol, dimethyl carbonate, phenol, etc. is added to the top of the first tower 13 The gas was continuously extracted in a gaseous state, passed through the heat exchanger 14, and extracted from the extraction port 16 at a flow rate of 34 tons / hr. On the other hand, the first tower high boiling point reaction mixture containing methyl phenyl carbonate, dimethyl carbonate, phenol, diphenyl carbonate, catalyst and the like was continuously extracted in liquid form from the bottom 17 of the first tower.

[0218] After 24 hours, a steady steady state was reached, and the raw material installed between the melapack and perforated plate tray of the second continuous multistage distillation column 201 was introduced as it was, with the high-boiling point reaction mixture in the first column introduced. It was continuously supplied from the port 21 at a flow rate of 66 tons / hr. The liquid supplied to the second continuous multistage distillation column 201 contained 18.2% by mass of methyl phenyl carbonate and 0.8% by mass of diphenyl carbonate. In the second continuous multistage distillation column 201, the reaction distillation was continuously performed under the conditions that the temperature at the bottom of the column was 210 ° C, the pressure at the top of the column was 3 × 10 ⁴ Pa, and the reflux ratio was 0.3. After 24 hours, stable steady operation was achieved. The second tower low boiling point reaction mixture containing 35% by mass of dimethyl carbonate and 56% by mass of phenol was continuously withdrawn from the top 23 of the second column, and the flow rate at the outlet 26 was 55.6 tons / hr. The second tower high boiling point reaction mixture containing 38.4% by weight of methyl phenyl carbonate and 55.6% by weight of diphenyl carbonate was continuously withdrawn from the bottom 27 of the second tower. The second column low boiling point reaction mixture was continuously supplied from the inlet 11 to the first continuous multistage distillation column 101. At this time, the amount of dimethyl carbonate and phenol to be newly supplied is adjusted so as to maintain the composition and amount of raw material 1 and raw material 2 in consideration of the composition and amount of the second tower low boiling point reaction mixture. Arranged. Diphenyl carbonate production was found to be 5.74 tons per hour. The selectivity for diphenyl carbonate was 98% with respect to the reacted phenol.

Yes

[0219] A long-term continuous operation was performed under these conditions. After 500 hours, 2000 hours, 4000 hours, 5000 hours, and 6000 hours, the production of diphenyl carbonate (excluding diphenyl carbonate contained in the raw material) is 5 · 74 tons per hour, 5 75 tons, 5.74 tons, 5.74 tons, 5.75 tons, and the selection rates were 98%, 98%, 98%, 98%, 98%, and were very stable. In addition, the produced aromatic carbonate was substantially free of halogen! / And not (lppb or less).

[0220] (3) Step of obtaining high-purity diphenyl carbonate (III) The second high boiling point reaction mixture extracted from the bottom of the second continuous multistage distillation column is continuously fed to a high boiling point material separation column (length 1700 cm, inner diameter 340 cm, 30 stages). Distillation was continuously performed at a temperature of 206 ° C, a pressure at the top of the column of 3800 Pa, and a reflux ratio of 0.6. The top component extracted continuously from the top of the high-boiling-point material separation tower is directly used as a diaryl carbonate purification tower having a side cut outlet (length: 2200 cm, inner diameter: 280 cm, the upper part from the inlet is 12 stages, 18 stages between the inlet and the side cut installed at the bottom, and 5 stages below the side cut. In the diaryl carbonate purification tower, distillation was continuously performed at a temperature of 213 ° C. at the bottom of the tower, a pressure of 5000 Pa at the top of the tower, and a reflux ratio of 1.5. The purity of diphenyl carbonate continuously extracted from the side cut outlet was 99.999% or more and the halogen content was 1ppb or less. The high purity diphenyl carbonate thus obtained was once stored in a molten state in a storage tank.

(4) Process for producing high-quality aromatic polycarbonate (IV)

Aromatic polycarbonate was produced using a guide contact flow type polymerizer as shown in Fig. 6. The material of this polymerization vessel is all stainless steel. This polymerization vessel has a cylindrical casing and a cone part, and L = l, 000 cm, h = 900 cm, D = 500 cm, d = 40 cm, C = 155 degrees, S = 250 m ² . The molten polymer supplied from the supply port 1 is uniformly distributed to each guide 4 by the perforated plate 2. An inert gas supply port 9 is provided at the lower part of the polymerization vessel, and a vacuum vent port 6 is provided at the upper part. The outside of the reactor is a jacket that is heated by a heating medium!

A molten polymer polybolymer (number average molecular weight Mn is 4,000) of aromatic polycarbonate maintained at 260 ° C produced from bisphenol A and the high-purity diphenyl carbonate (molar ratio of bisphenol A to 1.05). Then, it was continuously supplied from the supply port 1 to the supply zone 3 by the supply pump. The molten polymer that was continuously supplied to the polymerization reaction zone 5 through the perforated plate 2 in the polymerization vessel was allowed to flow along the guide 4 while the polymerization reaction proceeded. The polymerization reaction zone is maintained at 80 Pa through the vacuum vent 6. The produced aromatic polycarbonate that has entered the bottom 11 of the polymerization vessel from the bottom of the guide 4 is discharged from the discharge port 7 at a flow rate of 5.5 tons / hr by the discharge pump 8 so that the amount at the bottom becomes constant. Continuously I left.

[0222] The number average molecular weight Mn of the aromatic polycarbonate extracted from the extraction port 50 after 50 hours from the start of operation was 10,500, indicating a good color (b * value 3.2). . The tensile elongation was 98%. 60 hours, 100 hours, 500 hours, 1,000 hours, 2,000 hours, 3,000 hours, 4,000 hours, 5,000 hours and 5,000 hours after the start of operation The Mn values of the extracted aromatic polycarbonates are 10, 500, 10, 550, 10, 500, 10, 550, 10, 500, 10, 500, 10, 550, and 10, 500, respectively. there were.

The aromatic polycarbonate produced in this way has an alkali metal and / or alkaline earth metal compound content of 0.04-0.05ppm in terms of these metal elements and a chlorine content. Was less than lppb. The content of heterogeneous bonds was 0.12 to 0.15 monole%.

[0223] (5) Recycling process of phenol (V)

A phenol solution containing approximately 10% diphenyl carbonate and a small amount of bisphenol A recovered as a by-product in step (IV) and continuously in a phenol purification tower (length 1500 cm, internal diameter 2 70 cm, 9 stages) Supplied to Distillation was continuously carried out at a column bottom temperature of 185 ° C., a column top pressure of 2000 Pa and a reflux ratio of 0.9. The phenol recovered from the top of the column was once stored in a tank and then recycled to step (II). The diphenyl carbonate recovered from the side cut portion was supplied to the high boiling point substance separation column in step (III) and recovered as high purity diphenyl carbonate.

[Example 2]

(1) Step of continuously producing dimethyl carbonate and ethylene dalycol (I) Using the same continuous multi-stage distillation column as in Example 1, reactive distillation was performed under the following conditions.

Liquid ethylene carbonate 2.61 tons / hr was continuously introduced into the distillation column at the inlet (3-a) force installed at the 55th stage from the bottom. Gaseous methanol (dimethyl carbonate 2.41 wt ^_0/0 containing) 4.233 t / hr and liquid methanol (dimethyl carbonate containing 1.46 wt%) 4.227 t / hr is 31 stages from the bottom It was continuously introduced into the distillation column from the inlets (3-b and 3-c) installed in the eyes. The molar ratio of the raw materials introduced into the distillation tower is Methanol / ethylene carbonate = 8.73. The catalyst was continuously fed to the distillation column in the same manner as in Example 1. Reactive distillation was continuously carried out under the conditions that the temperature at the bottom of the column was 93 ° C, the pressure at the top of the column was about 1.04 6 X 10 ⁵ Pa, and the reflux ratio was 0.48.

[0225] After 24 hours, stable steady operation was achieved. The low boiling point reaction mixture withdrawn in the form of gas from the top 1 of the column was cooled with a heat exchanger to be liquid. The dimethyl carbonate in the liquid low boiling point reaction mixture continuously withdrawn from the distillation column at 8.17 tons / hr was 2.84 tons / hr, and methanol was 5.33 tons / hr. In the liquid continuously extracted at 937 tons / hr, ethylene glycol is 1.865 tons / hr, methanol is 1 · 062 tons / hr, unreacted ethylene carbonate. 0 · 2kg / hr. Excluding dimethyl carbonate contained in the raw material, the actual production amount of dimethyl carbonate per hour was 2.669 tons, and excluding ethylene glycol contained in the catalyst solution, the actual production amount of ethylene glycol per hour was 1. It was 839 tons. The reaction rate of ethylene carbonate was 99.99%, the selectivity of dimethyl carbonate was 99.99% or more, and the selectivity of ethylene glycol was 99.99% or more.

[0226] A long-term continuous operation was performed under these conditions. After 1000 hours, 2000 hours, 3000 hours, and 5000 hours, the actual production per hour is 2.669 tons, 2.669 tons, 2.669 tons, 2.669 tons for dimethyl carbonate. And ethylene! ; Corole power 1. 839 tons, 1. 839 tons, 1. 839 tons, 1. 839 tons, the reaction rate of ethylene carbonate is 99.99%, 99.99%, 99.99%, in 99.99 ^_0/0, the selectivity of dimethylol Honoré carbonate (or 99.99% or more, 99.99% or more, 99.99% or more, with 99.99% or more, selection択率ethylene glycol 99 - 99% or more, 99.99% or more, 99.99% or more, 99.99% or more.

[0227] (2) Step of continuously producing diphenyl carbonate (II)

Using the same apparatus as in Example 1, reactive distillation was performed under the following conditions.

Raw material 1 consisting of phenol / dimethyl carbonate = 1.1 (weight ratio) was continuously introduced in liquid form at a flow rate of 40 tons / hr from the upper inlet 11 of the first continuous multi-stage distillation column 101. On the other hand, the raw material 2 consisting of dimethyl carbonate / phenol = 3.9 (weight ratio) was continuously introduced in a gaseous state from the lower inlet 12 of the first continuous multi-stage distillation column 101 at a flow rate of 43 ton / hr. The molar ratio of the raw materials introduced into the first continuous multistage distillation column 101 is dimethyl carbonate / Enol = 1.87. This raw material was substantially free of halogen (outside the limit of detection by ion chromatography, lppb or less). The catalyst is Pb (OPh)

2 It was introduced from the upper inlet 11 of the first continuous multi-stage distillation column 101 so that the reaction solution was about 250 ppm. In the first continuous multi-stage distillation column 101, the temperature at the bottom of the column was 235 ° C, and the reactive distillation was continuously carried out under the pressure of S9 X 10 ⁵ Pa at the top of the column. The first tower low boiling point reaction mixture containing methyl alcohol, dimethyl carbonate, phenol, etc. is continuously withdrawn from the top 13 of the first tower in the form of gas, passed through the heat exchanger 14, and from the outlet 16 to 43 tons / hr. It was extracted at a flow rate of. On the other hand, the first tower high boiling point reaction mixture containing methyl phenyl carbonate, dimethyl carbonate, phenol, diphenyl carbonate, catalyst and the like was continuously extracted in liquid form from the bottom 17 of the first tower.

After 24 hours, a stable steady state was reached, so that the high-boiling reaction mixture in the first column was passed through the raw material inlet 21 installed between the melapack and the perforated plate tray in the second continuous multistage distillation column 201 as it was. , Continuously fed at a flow rate of 40 tons / hr. The liquid supplied to the second continuous multistage distillation column 201 contained 20.7% by mass of methyl phenyl carbonate and 1.0% by mass of diphenyl carbonate. In the second continuous multi-stage distillation column 201, reactive distillation was continuously performed under the conditions that the temperature at the bottom of the column was 205 ° C, the pressure at the top of the column was 2 × 10 ⁴ Pa, and the reflux ratio was 0.5. After 24 hours, stable steady operation was achieved. The second tower low boiling point reaction mixture is continuously withdrawn from the second tower top 23, and the second tower bottom 27 contains 36.2% by weight methylphenyl carbonate and 60.8% by weight diphenyl carbonate. Two towers high boiling point reaction mixture was continuously withdrawn. The second column low boiling point reaction mixture was continuously supplied to the first continuous multistage distillation column 101 from the inlet 11. At this time, the amount of dimethyl carbonate and phenol to be newly supplied should be such that the composition and amount of raw material 1 and raw material 2 are maintained in consideration of the composition and amount of the second tower low boiling point reaction mixture. It was adjusted. Production of diphenyl carbonate was found to be 4.03 tonnes per hour. The selectivity for diphenyl carbonate was 97% with respect to the reacted phenol.

Long-term continuous operation was performed under these conditions. After 500 hours, 1000 hours, and 2000 hours, the production per hour for Diphenolino Carbonate was 4.03, 4.03, and 4.04, compared to the reacted phenol. Selectivity is 97%, 97%, 97%, very stable Was. Also, the produced aromatic carbonate was substantially free of halogen (l ppb or less).

[0229] (3) Step of obtaining high-purity diphenyl carbonate (III)

This was carried out in the same manner as in Example 1.

[0230] (4) Process for producing high-quality aromatic polycarbonate (IV)

In the same polymerization vessel as in Example 1, an aromatic polycarbonate melt prepolymer (number average molecular weight Mn is 3,5) produced from bisphenol A and high-purity diphenyl carbonate (molar ratio of bisphenol A to 1 · 05). 500) Continuously supplied from supply port 1 to supply zone 3 by 1S supply pump. An aromatic polycarbonate was produced by polymerization in the same manner as in Example 1 except that the pressure in the polymerization reaction zone was maintained at l OOPa. Start of operation Taihyo, La, 50 days after temple, 100 days after temple, 500 days after temple, 1,000 days after temple, 2,000 days after temple, 3, 00 hours later, 4, After 000 hours and after 5,000 hours, the Mn of the aromatic poly-bonate discharged from the outlet 19 is 7,600, 7,600, 7,650 7,600, 7,650, 7,65 0, respectively. 7, 600, 7, 600 and stable.

The aromatic polycarbonate produced in this manner has an alkali metal and / or alkaline earth metal compound content of 0.03 force, et al. The content was lppb or less. Further, the content of heterogeneous bonds was 0.08 to 0.1 monole%.

[0231] (5) Recycling process of phenol (V)

This was carried out in the same manner as in Example 1.

[0232] [Example 3]

(1) Process for continuous production of dimethyl carbonate and ethylene dalycol (I) L = 3300cm, D = 300cm, L / Ό = 1 1, η = 60, D / ά as shown in Fig. 1

0 0 0 0 0 0 0

1 0 02

As the internal plate, a perforated plate tray having a cross-sectional area per hole of the perforated plate portion = about 1.3 cm ² and the number of holes = about 220 to 340 / m ² was used.

Liquid ethylene carbonate 3.773 tons / hr was continuously introduced into the distillation column from the inlet (3-a) installed at the 55th stage from the bottom. Gaseous methanol (dimethyl carbonate 8 - 97 mass DOO ^_0/0 included) 3 - 736 t / hr and liquid methanol (dimethyl carbonate 6.65 containing mass%) 8.641 t / hr force S, placed at the 31 st stage from the bottom It was continuously introduced into the distillation column from the inlet (3-b and 3-c). The molar ratio of the raw materials introduced into the distillation column was methanol / ethylene carbonate = 8.73. The catalyst was continuously fed to the distillation column in the same manner as in Example 1. Reactive distillation was continuously carried out under the conditions that the temperature at the bottom of the column was 98 ° C., the pressure at the top of the column was about 1.118 × 10 ⁵ Pa, and the reflux ratio was 0.42.

[0233] Stable steady operation was achieved after 24 hours. The low boiling point reaction mixture withdrawn in the form of gas from the top of the column was cooled to a liquid by a heat exchanger. The dimethyl carbonate in the liquid low-boiling-point reaction mixture continuously withdrawn from the distillation column at 12.32 ton / hr was 4. 764 ton / hr, and the methanol was 7.556 ton / hr. In the liquid continuously withdrawn at 902 tons / hr, ethylene glycol is 2.718 tons / hr, methanol is 1 · 17 tons / hr, unreacted ethylene carbonate It was 4.6kg / hr. Excluding dimethyl carbonate contained in the raw material, the actual production amount of dimethyl carbonate per hour was 3,854 tons, and excluding ethylene glycol contained in the catalyst solution, the actual production amount of ethylene glycol per hour was 2. It was 655 tons. The reaction rate of ethylene carbonate was 99.88%, the selectivity of dimethyl carbonate was 99.99% or more, and the selectivity of ethylene glycol was 99.99% or more.

[0234] A long-term continuous operation was performed under these conditions. After 1000 hours, 2000 hours, 3000 hours, and 5000 hours, the actual production volume per hour is 3.854 tons, 3.854 tons, 3.854 tons, and 3.854 tons for dimethyl carbonate. The ethylene glycol power is 2.655, 2.655, 2.655, 2.655 and the reaction rate of ethylene carbonate is 99.9%, 99. 99%, 99.99% and 99.99 ^_0/0, the selectivity of dimethylol Honoré carbonate (or 99.99% or more, 99.99% or more, with 99.99% or more, 99.99% or more, ethylene Glycol selection rates were 99 · 99% or higher, 99.99% or higher, 99.99% or higher, 99.99% or higher.

[0235] (2) Step of continuously producing diphenyl carbonate (II)

Reactive distillation was performed under the following conditions using the same apparatus as in Example 1 except that the cross-sectional area per hole of the perforated plate tray in the second continuous multistage distillation column 201 was about 1.8 cm ² . Raw material 1 consisting of phenol / dimethyl carbonate = 1.7 (weight ratio) in the first continuous multistage Liquid was continuously introduced at a flow rate of 86 tons / hr from the upper inlet 11 of the distillation column 101. On the other hand, raw material 2 composed of dimethyl carbonate / phenol = 3.5 (weight ratio) was continuously introduced in a gaseous state from the lower inlet 12 of the first continuous multi-stage distillation column 101 at a flow rate of 90 tons / hr. The molar ratio of the raw materials introduced into the first continuous multistage distillation column 101 was dimethyl carbonate / phenol = 1.44. This raw material was substantially free of halogen (outside the limit of detection by ion chromatography, lppb or less). The catalyst is Pb (OPh)

2 It was introduced from the upper inlet 11 of the first continuous multi-stage distillation column 101 so that the reaction solution was about 150 ppm. In the first continuous multistage distillation column 101, the temperature at the bottom of the column was 220 ° C., and the reactive distillation was continuously carried out under the conditions of the pressure at the top of the column of S8 × 10 ⁵ Pa. The first tower low boiling point reaction mixture containing methyl alcohol, dimethyl carbonate, phenol, etc. is continuously withdrawn in the form of a gas from the top 13 of the first tower, passed through the heat exchanger 14, and from the outlet 16 to 82 tons / hr. It was extracted at a flow rate of. On the other hand, the first tower high boiling point reaction mixture containing methyl phenyl carbonate, dimethyl carbonate, phenol, diphenyl carbonate, catalyst and the like was continuously extracted in liquid form from the bottom 17 of the first tower.

After 24 hours, a stable steady state was reached, so that the high-boiling reaction mixture in the first column was passed through the raw material inlet 21 installed between the melapack and the perforated plate tray in the second continuous multistage distillation column 201 as it was. , Continuously supplied at a flow rate of 94 tons / hr. The liquid supplied to the second continuous multistage distillation column 201 contained 16.0% by mass of methylphenyl carbonate and 0.5% by mass of diphenyl carbonate. In the second continuous multi-stage distillation column 201, the reaction distillation is continuously performed under the conditions that the temperature at the bottom of the column is 215 ° C, the pressure at the top of the column is 2.5 X 10 ⁴ Pa, and the reflux ratio is 0.4. It was broken. After 24 hours, stable steady operation was achieved. The second tower low boiling point reaction mixture is continuously withdrawn from the second tower top 23, and the second tower bottom 27 contains 35.5% by weight of methyl phenyl carbonate and 59.5% by weight of diphenyl carbonate. Second column The high boiling point reaction mixture was continuously withdrawn. The second column low boiling point reaction mixture was continuously supplied to the first continuous multistage distillation column 101 from the inlet 11. At this time, the amount of dimethyl carbonate and phenol to be newly supplied should be such that the composition and amount of raw material 1 and raw material 2 are maintained in consideration of the composition and amount of the second tower low boiling point reaction mixture. It was adjusted. Diphenyl carbonate production was found to be 7.28 tons per hour. Reacted eno The selectivity for diphenyl carbonate was 98%.

Long-term continuous operation was performed under these conditions. After 500 hours, 1000 hours, and 2000 hours, the production volume of diphenyl carbonate was 7.28, 7.29, and 7.29, compared to the reacted phenol. The selectivity was 98%, 98% and 98%, and was very stable. In addition, the produced aromatic carbonate contained substantially no halogen (lppb or less).

[0237] (3) Step of obtaining high-purity diphenyl carbonate (III)

This was carried out in the same manner as in Example 1.

[0238] (4) Process for producing high-quality aromatic polycarbonate (IV)

Aromatic polycarbonate was produced using a polymerization apparatus in which two guided contact flow type polymerization reactors as shown in Fig. 6 were arranged in series. The material of these polymerization vessels is all stainless steel. Guide contact flow type first polymerizer has cylindrical casing and cone part, L = 950cm, h = 850cm, D = 400cm, d = 20cm, C = 150 degree, S = 750m ² . The second polymerization vessel is the same as that used in Example 1.

[0239] An aromatic polycarbonate melt polymer (number average molecular weight Mn is 2,500) made from bisphenol A and high-purity diphenyl carbonate (molar ratio of bisphenol A to 1.06) is supplied by a feed pump. 1 Continuously fed to feed zone 3 from feed port 1 of the polymerization vessel. The molten prepolymer, which was continuously supplied to the polymerization reaction zone through the perforated plate 2 in the first polymerization vessel, proceeded with the polymerization reaction while flowing down along the guide 4. The polymerization reaction zone of the first polymerization vessel is maintained at a pressure of 800 Pa through the vacuum vent 6. An aromatic polycarbonate molten prepolymer (number average molecular weight Mn is 5,500) having increased degree of polymerization that has entered the bottom 11 of the polymerization vessel from the bottom of the guide 4 so that the amount at the bottom is constant. Then, it was continuously extracted from the discharge port 7 at a constant flow rate by the discharge pump 8. This molten prepolymer was continuously fed to feed zone 3 from feed port 1 of the second polymerization vessel by a feed pump. The molten prepolymer, which was continuously supplied to the polymerization reaction zone through the perforated plate 2 in the second polymerization vessel, proceeded with the polymerization reaction while flowing down along the guide 4. The polymerization reaction zone of the second polymerization vessel is maintained at a pressure of 50 Pa through the vacuum vent 6. Aroma produced from the bottom of the guide 4 into the bottom 11 of the second polymerization vessel The group polycarbonate was continuously extracted from the discharge port 7 at a flow rate of 6 tons / hr by the discharge pump 8 so that the amount at the bottom was constant.

[0240] The number average molecular weight Mn of the aromatic polycarbonate extracted from the outlet 12 of the second polymerization vessel 50 hours after the start of operation was 11,500, indicating a good color (b * value 3.2). ) Met. The tensile elongation was 99%. 60 hours, 100 hours, 500 hours, 1,000 hours, 2,000 hours, 3,000 hours, 4,000 hours, 5,000 hours and 5,000 hours after the start of operation Mn of the extracted aromatic polycarbonate is 11, 500, 11, 550, 11, 500, 11, 550, 11, 500, 11, 500, 11, 550, 11, 500 and stable Met.

The aromatic polycarbonate produced in this manner has an alkali metal and / or alkaline earth metal compound content of 0.03 force, et al. The content was lppb or less. The content of heterogeneous bonds was 0.11 to 0.16 monole%.

[0241] (5) Recycling process of aromatic monohydroxy compounds (V)

This was carried out in the same manner as in Example 1.

Industrial applicability

[0242] According to the present invention, a high-quality, high-performance aromatic polycarbonate that is not colored and has excellent mechanical properties from a cyclic carbonate and an aromatic dihydroxy compound is 1 ton or more per hour at a high polymerization rate. Can be manufactured on an industrial scale. In addition, a high-quality aromatic polycarbonate can be stably produced for a long period of time with little variation in molecular weight, for example, 2000 hours or longer, preferably 3000 hours or longer, more preferably 5000 hours or longer. Therefore, the present invention is a method having an extremely excellent effect as an industrial production method of high-quality aromatic polycarbonate.

Brief Description of Drawings

[0243] FIG. 1 is a schematic view of a continuous reaction distillation column preferable for carrying out the present invention. Inside the torso

0

Is provided with an internal plate tray.

FIG. 2 is a schematic view of a first continuous reaction distillation column preferable for carrying out the present invention. An internal is installed inside the torso. 3] It is a schematic view of a second continuous reaction distillation column preferable for carrying out the present invention. Inside the barrel is an internal packing consisting of regular packing at the top and a perforated plate tray at the bottom.

FIG. 4 is a schematic view of an apparatus in which a first continuous reactive distillation column and a second continuous reactive distillation column are connected, which is preferable for carrying out the present invention.

FIG. 5 is a schematic view of a preferred guide contact flow type polymerization apparatus for carrying out the present invention. 6] is a schematic view of a guide contact flow type polymerizer having a cylindrical side casing and a tapered bottom casing which are preferable for carrying out the present invention.

Explanation of symbols

(Figure 1)

1: Gas outlet, 2: Liquid outlet, 3—a to 3—e: Inlet, 4—a to 4—b: Inlet, 5: End plate, 6: Internal, 7: Body part, 10 : Continuous multistage distillation column, L: trunk length (cm),

0

0: Body inner diameter (111), (1: Inner diameter of gas outlet (cm), d: Inner diameter of liquid outlet (cm)

0 01 02

(Figure 2, Figure 3 and Figure 4)

1: Gas outlet, 2: Liquid outlet, 3: Inlet, 4: Inlet, 5: End plate, L, L: Body length

1 2 Depth (cm), D, D: Monthly inner diameter (cm), d, d: Gas outlet inner diameter (cm), d, d: Drain

1 1 11 21 12 22 Outlet inner diameter (cm), 101: First continuous multistage distillation column, 201: Second continuous multistage distillation column, 11, 12, 21: Inlet, 13, 23: Top gas outlet 14, 24, 18, 28: Heat exchanger, 17, 27: Tower bottom outlet, 16, 26: Tower top outlet, 31: Second bottom multistage distillation tower bottom outlet

(Fig. 5 and Fig. 6)

1: Melt prepolymer receiving port, 2: Perforated plate, 3: Melt prepolymer feed zone, 4: Guide, 5: Polymerization reaction zone, 6: Vacuum vent port, 7: Aromatic polycarbonate discharge port, 8: Aromatic polycarbonate discharge pump 9: Inert gas supply port used as required 10: Side casing of polymerization reaction zone 11: Tapered bottom casing of polymerization reaction zone 12: Extraction port of aromatic polycarbonate

Claims

An industrial production method for continuously producing a high-quality aromatic polycarbonate from a cyclic carbonate and an aromatic dihydroxy compound, wherein (I) a continuous multistage in which a catalyst is present between the cyclic carbonate and an aliphatic monohydric alcohol. Continuously supplying into the distillation column T, reaction and distillation are simultaneously carried out in the column, and the low-boiling point reaction mixture containing the dialkyl strength 0-bonate formed is continuously withdrawn in the form of gas from the top of the column, A step (I) of continuously producing a dialkyl carbonate and a diol by a reactive distillation system in which a high boiling point reaction mixture containing liquid is continuously extracted from the bottom of the column in a liquid state; and (II) the dialkyl carbonate and aromatic monohydroxy Compound is used as a raw material, and this raw material is continuously fed into the first continuous multi-stage distillation column in which the catalyst exists, and the reaction and distillation are simultaneously performed in the first column to produce The first column low-boiling point reaction mixture containing alcohols is continuously withdrawn from the upper portion of the first column in the form of gas, and the first column high-boiling point reaction mixture containing the generated alkylaryl carbonates is removed from the lower portion of the first column. The liquid is continuously extracted in a liquid state, and the first tower high boiling point reaction mixture is continuously fed into the second continuous multistage distillation tower in which the catalyst is present, and the reaction and distillation are simultaneously performed in the second tower to produce. Second column low-boiling point reaction mixture containing dialkyl carbonates is continuously withdrawn in the form of gas from the upper part of the second column, and the second tower high-boiling point reaction mixture containing diaryl carbonates is liquidized from the lower part of the second column. On the other hand, the second column low boiling point reaction mixture containing dialkyl carbonates is continuously fed into the first continuous multistage distillation column to continuously produce diaryl carbonate ( II) and (III) purification step (III) for purifying the diaryl carbonate to obtain high purity diaryl carbonate; and (IV) reacting the aromatic dihydroxy compound with the high purity diaryl carbonate. An aromatic polycarbonate is produced by using a guide contact flow type polymerizer in which a molten polymer precursor of the aromatic polycarbonate is produced, the molten polymer is flowed down along the surface of the guide, and the molten polymer is polymerized during the flow. Step (IV), and (V) recycling step (V) of the aromatic monohydroxy compound in which the aromatic monohydroxy compound by-produced in step (IV) is recycled to the diaryl carbonate production step (II), (A) The continuous multi-stage distillation column has a cylindrical body having a T force S, a length L (cm), and an inner diameter D (cm), and has an internal with 0 0 0 inside n Structure and tower A gas outlet with an inner diameter d (cm) at the top or near the top of the 0 tower, a liquid outlet with an inner diameter of 01 (d) at the bottom or near the bottom of the tower, and below the gas outlet. And / or 02 has one or more first inlets in the middle and one or more second inlets in the middle and / or lower part of the tower above the liquid outlet. L, D, L / D 0 0 0 0, n, D / d, D / d ί satisfying formulas (1) to (6), and 0 01 0 02 2100 <L ≤ 8000 formula (1) 0 180 <D ≤ 2000 formula (2) 0 4 <L / Ε) ≤ 40 formula (3) 0 0 10 <η ≤ 120 formula (4) 0 3 <D / ά ≤ 20 formula ( 5) 0 01 5 <D / ά ≤ 30 (6) (b) The first continuous multi-stage distillation column has a cylindrical body having a length L (cm) and an inner diameter D (cm), and has an internal The gas outlet has an internal diameter d (cm) at the top of the tower or near the top of the tower. One or more third inlets at the bottom of the tower or near the bottom of the tower, with a liquid outlet of 11 inner diameter d (cm), below the gas outlet and above the tower and / or in the middle Having one or more fourth inlets above the liquid outlet and in the middle and / or lower part of the column, and L, D, L / D, n, D / d, D / d force, which satisfies Eqs. (7) to (; 12) respectively, 1500 <L <8000 formula (7) 1 100 <D <2000 formula (8) 1 2 <L / '≤ 40 formula ( 9) 1 1 20 <n <120 (10) 1 5 <D, Zd ≤ 30 (11) 1 11 3 <D, Zd ≤ 20 (12) 1 12 (c) The second continuous multi-stage distillation column Has a cylindrical body with a length L (cm) and an inner diameter D (cm), and has an internal structure with an internal number n, and the top of the tower or the top of the tower close to it A gas outlet with an inner diameter d (cm), a liquid outlet with an inner diameter d (cm) at the bottom of the tower or near the bottom of the tower, One or more fifth inlets below the gas outlet and at the top and / or middle of the tower and one above the liquid outlet and one at the middle and / or bottom of the tower It has the above sixth inlet, L, D, L / 22 2D, n, D / d, D / d force respectively satisfy the formulas (13) to (18), 2 2 2 21 2 22 1500 ≤ L ≤ 8000 Equation (13) 2 100 ≤ D ≤ 2000 Equation (14) 2 2 ≤ L / Ό ≤ 40 Equation (15) 2 2 10 ≤ n ≤ 80 Equation (16) 2 2 ≤ D / d ≤ 15 Equation (17) 2 21 5 ≤ D / d ≤ 30 Equation (18) 2 22 (d)

(1) A molten prepolymer feed port, a perforated plate, a molten prepolymer feed zone for feeding the melted prepolymer to the guide of the polymerization reaction zone through the perforated plate, the perforated plate, a side casing, and a tapered bottom casing. A polymerization reaction zone provided with a plurality of guides extending downward from the perforated plate in the enclosed space, a vacuum vent port provided in the polymerization reaction zone, and an aromatic provided at the bottom of the tapered bottom casing A polycarbonate discharge port, and an aromatic polycarbonate discharge pump connected to the discharge port,

0. 7 ≤ A ≤ 300 Equation (19)

20 ≤ A / B ≤ 1000 formula (20)

(4) A tapered bottom casing constituting the bottom of the polymerization reaction zone is connected to the upper side casing at an angle C degree inside thereof, and the angle C degree Satisfies the formula (21),

120 ≤ C ≤ 165 Equation (21)

(5) The length h of the guide (cmWS, which satisfies equation (22),

150 ≤ h ≤ 5000 (22)

2 ≤ S ≤ 50000 Equation (23)

An industrial process for producing high-quality aromatic polycarbonate, characterized in that

[2] The method according to claim 1, wherein the produced aromatic polycarbonate is 1 ton or more per hour.

[3] The d and the d of the continuous multistage distillation column T used in the step (I) satisfy the formula (24).

0 01 02

The method according to claim 1, wherein:

1 ≤ d / d ≤ 5 Equation (24)

01 02

[4] L, D, L / D, n, D / d, D / d of the continuous multistage distillation column T are 2 respectively.

0 0 0 0 0 0 0 01 0 02

300≤L ≤6000, 200≤D ≤1000, 5≤L / Ό ≤30, 30≤η ≤100, 4

0 0 0 0 0

≤Ό / ά ≤15, 7≤D / ά ≤25, any one of claims 1-3

0 01 0 02

The method according to claim 1.

[5] L, D, L / D, n, D / d, D / d of the continuous multistage distillation column 2 are 2

0 0 0 0 0 0 0 01 0 02

500≤L ≤5000, 210≤D ≤800, 7≤L / Ό ≤20, 40≤η ≤90, 5≤D

0 0 0 0 0 C

Any one of claims 1 to 4, wherein / ά ≤13, 9≤D / ά ≤20

01 0 02

The method according to any one of the above.

[6] the continuous multistage distillation column τ force with tray and / or packing as the internal

0

The method according to any one of claims 1 to 5, wherein the method is a distillation column.

Yes

[7] The continuous multistage distillation column Τ is a plate type distillation column having a tray as the internal

0

The method according to claim 6.

[8] Perforated plate tray in which the tray of the continuous multistage distillation column has a perforated plate portion and a downcomer portion

0

The method according to claim 6 or 7, wherein:

[9] The perforated plate tray of the continuous multi-stage distillation column is 100 to 100 per lm ^{2 of the} perforated plate portion; 9. A method according to claim 8, characterized in that it has zero holes.

[10] The cross-sectional area per hole of the perforated plate tray of the continuous multistage distillation column T is 0.5 to ⁵ cm ^2.

0

10. A method according to claim 8 or 9, characterized in that

[11] Opening ratio of the perforated plate tray of the continuous multi-stage distillation column T (total holes relative to the area of the perforated plate portion)

0

11. The method according to claim 8, wherein the ratio of the cross-sectional area is 1.5 to 15%.

[12] The first continuous multi-stage distillation column used in step (II), the first continuous multi-stage distillation column d and the d

11 1 satisfies expression (25), and d and d satisfy expression (26),

2 21 22

; The method according to any one of! To 11.

1 ≤ d / d ≤ 5 Equation (25)

12 11

1 ≤ d / d ≤ 6 Equation (26)

21 22

[13] L, D, L / D, n, D / d, D / άS of the first continuous multistage distillation column used in step (II), 2000≤L≤6000, 150≤D≤1000 , 3≤L / D≤30,

12 1 1 1 1

30≤n≤100, 8≤D / d≤25, 5≤D / d≤18, and

1 1 11 1 12

2 2 2 2 2 2 21 2 22

000≤L≤6000, 150≤D ≤1000, 3≤L / D ≤30, 15≤n≤60, 2.5

2 2 2 2 2

≤D / d ≤12, 7≤D / d ≤25, any one of claims 1-12

2 21 2 22

The method according to any one of the above.

[14] L, D, L / D, n, D / d, D / d of the first continuous multistage distillation column are 2 respectively.

1 1 1 1 1 1 11 1 12

500≤L≤5000, 200≤D≤800, 5≤L / D≤15, 40≤n≤90, 10≤D / d≤25, 7≤D / d≤15, and

1 11 1 12

2 2 2 2 2 2 21 2 22

500≤L≤5000, 200≤D ≤800, 5≤L / D ≤15, 20≤n≤50, 3≤D

2 2 2 2 2 2

/ d ≤10, 9≤D / d ≤20, any one of claims 1-13

21 2 22

The method according to item.

15. The method according to any one of claims 1 to 14, wherein the first continuous multistage distillation column and the second continuous multistage distillation column are distillation columns each having a tray and / or a packing as the internal. The method according to claim 1.

[16] The first continuous multi-stage distillation column is a tray-type distillation column having a tray as the internal, and the second continuous multi-stage distillation column has both a packing and a tray as the internal. The method according to claim 15, which is a distillation column.

[17] The perforated plate tray of each of the first continuous multistage distillation column and the second continuous multistage distillation column is a perforated plate tray having a perforated plate portion and a downcomer portion.

6. The method according to 6.

[18] according to the porous plate tray of the first continuous multi-stage distillation column and said second continuous multi-stage distillation column is characterized in that having an area lm ² 100 to 1000 holes of the porous plate Item 17. The method according to item 7.

[19] The cross-sectional area per hole of the perforated plate tray of the first continuous multistage distillation column and the second continuous multistage distillation column is 0.5 to ⁵ cm2, or 18. The method according to 18.

20. The method according to claim 15 or 16, wherein the second continuous multi-stage distillation column is a distillation column having a packing as an upper part and a tray as a lower part as the internal.

[21] The packing according to any one of claims 15 to 20, wherein the packing of the internal of the second continuous multistage distillation column is one or two or more regular packings. Method.

[22] The regular packing of the second continuous multistage distillation column is at least one selected from a mela pack, a gem pack, a techno bag, a flexi pack, a sulza packing, a good roll packing, and a glitch grid. The method of claim 21.

[23] The method according to any one of [1] to [22], wherein the diaryl carbonate purification step (III) is distillation.

[24] In the guided contact flow type polymerization reactor used in step (IV), the side casing of the polymerization reaction zone has a cylindrical shape with an inner diameter D (cm) and a length L (cm). The bottom casing connected to the lower part is tapered, and the lowermost discharge port of the tapered bottom casing is cylindrical with an inner diameter d (cm), and D, L, d are expressed by the formula (27 ), (28), (29) and (30) are satisfied,

100 ≤ D ≤ 1800 Formula (27)

5 ≤ D / d ≤ 50 Equation (28)

0.5 ≤ L / D ≤ 30 (29) h-20 ≤ L ≤ h + 300 (30)

24. The method according to any one of claims 1 to 23, wherein:

[25] The h of the guide satisfies equation (31).

400 <h ≤ 2500 formula (31)

25. The method according to any one of claims 1 to 24, wherein:

[26] One of the guides is a cylindrical shape having an outer diameter r (cm) or a pipe shape in which a molten prepolymer is prevented from entering, and r satisfies the formula (32).

0. 1 ≤ r ≤ 1 (32)

26. The method according to any one of claims 1 to 25, wherein:

[27] The method according to any one of [1] to [26], wherein in the step (IV), the polymerization is carried out by connecting two or more guide contact flow type polymerization reactors.

[28] The two or more guide contact flow type polymerizers according to claim 27 are two polymerizers, a guide contact flow type first polymerizer and a guide contact flow type second polymerizer, in this order. In the method of increasing the degree of polymerization, the total external surface area SI (m ² ) of the entire guide of the first polymerization apparatus and the external total surface area S2 (m ² ) of the entire guide of the second polymerization apparatus are expressed by the equation (33). )

1 ≤ S1 / S2 ≤ 20 Equation (33)

28. The method of claim 27, wherein:

[29] A high-quality aromatic polycarbonate produced by 1 ton or more per hour by the method according to any one of claims 1 to 28.

[30] The content power of the alkali metal and / or alkaline earth metal compound is converted to these metal elements and is 0.;! To 0. Olppm, and the halogen content is lppb or less. 30. A high-quality aromatic polycarbonate according to claim 29.

[31] An aromatic polycarbonate partially branched from the main chain via a hetero bond such as an ester bond or an ether bond, and the content of the hetero bond is 0 with respect to the carbonate bond. The high-quality aromatic polycarbonate according to claim 29 or 30, characterized in that the content is 05-0. 5 mol%.