JP3199644B2 - Method for producing aromatic polycarbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic polycarbonate.

[0002]

2. Description of the Related Art In recent years, aromatic polycarbonates have been widely used in many fields as engineering plastics having excellent heat resistance, impact resistance and transparency. Various studies have hitherto been made on the method for producing the aromatic polycarbonate, and among them, an aromatic dihydroxy compound, for example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) and phosgene. Has been industrialized.

However, in this interfacial polycondensation method, toxic phosgene must be used, and the apparatus is corroded by by-produced hydrogen chloride and sodium chloride and a chlorine-containing compound such as methylene chloride used in large quantities as a solvent. In addition, there were problems such as difficulty in separating impurities such as sodium chloride and residual methylene chloride which adversely affect the physical properties of the polymer.

On the other hand, as a method for producing an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate, for example, a transesterification of bisphenol A and diphenyl carbonate in a molten state is carried out, and an ester is polymerized while extracting by-product phenol. Exchange methods have been known for some time. Unlike the interfacial polycondensation method, the transesterification method has the advantage of not using a solvent.On the other hand, as the polymerization proceeds, the viscosity of the polymer increases, making it difficult to efficiently remove by-products such as phenol from the system. And there is an essential problem that it is difficult to increase the degree of polymerization.

Conventionally, various types of polymerizers have been known as a polymerizer for producing an aromatic polycarbonate by a transesterification method. A method using a vertical stirring tank type polymerization vessel equipped with a stirrer is generally widely known. However, although the vertical stirring tank type polymerization vessel has the advantage of high volumetric efficiency and simplicity, polymerization can proceed efficiently on a small scale, but on an industrial scale, as described above, as the polymerization progresses. There is a problem that it is difficult to efficiently extract by-product phenol to the outside of the system, and the polymerization rate becomes extremely low.

That is, in a large-scale vertical stirred tank type polymerization vessel, the ratio of the liquid volume to the evaporation area is generally larger than that in the case of a small-scale polymerization vessel, and the so-called liquid depth is large. In this case, even if the degree of vacuum is increased in order to increase the degree of polymerization, the lower part of the agitation tank is polymerized at a substantially high pressure due to the liquid depth, and phenol and the like are efficiently removed. It becomes difficult.

In order to solve this problem, various devices have been devised for extracting phenol and the like from a polymer in a high viscosity state. For example, in Japanese Patent Publication No. 50-19600, a method using a screw type polymerizer having a vent portion, in Japanese Patent Publication No. 52-36159, a method using an interlocking twin-screw extruder, and in Japanese Patent Publication No. 53-5718, a thin film evaporation method is used. A method using a type reactor, for example, a screw evaporator or a centrifugal thin film evaporator is described.
No. 53923 specifically discloses a method using a combination of a centrifugal thin film evaporator and a horizontal stirring polymerization tank.

Among these polymerization vessels, horizontal polymerization vessels such as a screw type evaporator and a horizontal stirring tank are intended to efficiently extract phenol and the like by increasing the surface renewability as much as possible mainly by rotational stirring. Things. For example,
No. 0-19600 states that "a relatively large and constantly renewing phase boundary is created between the liquid reaction mixture and the gas or vapor space, whereby the vaporizable reaction product which separates from the liquid reactant. Will be removed very quickly. "
It is suggested that phenol and the like can be effectively extracted by the effect of renewing the surface of the gas-liquid interface. In Japanese Patent Publication No. 52-36159, the surface renewal effect J is determined by the number of rotations of the screw, the screw surface area of the reaction section, the total number of pitches of the screw in the reaction section, the raw material supply amount, and the total effective volume per pitch of the screw in the reaction section. It is defined as a function, and the importance of its value being within a predetermined range is pointed out.

[0009] However, these polymerization reactors require rotational stirring power such as a screw or a stirring shaft in order to enhance the surface renewability. However, the viscosity of an aromatic polycarbonate becomes extremely high particularly as the molecular weight becomes higher. Therefore, very large power is required. In addition, when the viscosity is high, no matter how much power is used, the polymer receives a large share, so that the molecular chain is broken, and as a result, the molecular weight rise rate is slow, and it is necessary to produce a high molecular weight aromatic polycarbonate. Can not. Further, the polymer quality was seriously affected, for example, the polymer was colored due to receiving a large share. Further, when the method is carried out on an industrial scale, the size of the apparatus is limited due to the limitation of the strength and power of the stirring shaft, and there is a problem that the production amount of the aromatic polycarbonate cannot be easily increased.

On the other hand, as for the centrifugal thin film evaporator, Japanese Patent Application Laid-Open No. 2-153923 discloses that when a centrifugal thin film evaporator is used as a polycondensation reactor in the final stage of the transesterification reaction, a unit treatment of the reaction mixture is performed. Since the evaporating surface area per unit volume can be increased, the residence time of the reaction mixture in the centrifugal thin film evaporator can be shortened, but some of the generated polymer adheres to the rotating shaft, blades, internal bearings, etc. It has been pointed out that there is a problem in that the blackened decomposition product is mixed into the polymer due to the heat history. In order to avoid this problem, the publication discloses a method of using a centrifugal thin film evaporator at an intermediate stage, not at the final stage of the transesterification reaction. However,
Since the centrifugal thin film evaporator forms a thin film only on the inner wall of the evaporator, the volumetric efficiency as a polymerization vessel is extremely small,
If a sufficient reaction time is to be obtained, the reactor becomes too large, which has another problem that it is not industrially preferable.

As a means for solving such a problem, the present inventors disclosed in Japanese Patent Application Laid-Open No. Hei 7-292,097 a method of polymerizing while free falling from a perforated plate. It was revealed that it can be produced at a high polymerization rate. In addition, in the comparative example of this publication, a method of performing polymerization while dropping along a wire is also shown. However, in order to further improve productivity, it is necessary to generate foreign matter with a polymerization vessel as small as possible. There is a need for a process for producing more aromatic polycarbonates.

[0012]

When an aromatic polycarbonate is produced by a transesterification method which does not have a problem of separation of impurities and residual methylene chloride, a vertical stirred tank type polymerizer, a horizontal type polymerizer, and a centrifugal thin film type polymerizer are used. In the conventional polymerization method using phenol, etc., the poor extraction efficiency of phenol, the magnitude of stirring power, the breaking of molecular chains due to shear and the decrease in the rate of increase in molecular weight, the coloring of polymers, and the long heat history There were various problems such as mixing of the decomposed product into the polymer and low volumetric efficiency. The object of the present invention is to eliminate these problems and to color more aromatic polycarbonate in a polymerization vessel as small as possible,
An object of the present invention is to provide a highly productive industrially preferable method which can be produced without generating foreign matter.

[0013]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have found that the purpose can be achieved by performing polymerization using a specific polymerization vessel. The invention has been completed. That is, the present invention relates to (1) the production of an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate using a polymerizer that is polymerized while being dropped along an interior product, and the total surface area S ( m ² ), the ratio S / V of the respective numerical values of the polymerization vessel internal volume V (m ³ ) is in the range of 0.1 to 300, and the numerical value of the clearance L (m) between the interior surface and the polymerization reactor inner wall surface is The production of an aromatic polycarbonate, characterized by using a polymerization vessel satisfying the following formula (I) with respect to the number average molecular weight Mn of the aromatic polycarbonate to be produced: L ≧ 5 × 10 ⁻⁶ Mn (I) (2) The aromatic polycarbonate according to the above (1), wherein the interior product is an interior product vertically connected from the upper portion of the polymerization reactor to the lower portion of the polymerization device, and a plurality of the interior components are used in the polymerization device. Method for producing a sulfonate, there is provided a.

Conventionally, when an aromatic polycarbonate is to be produced by efficiently extracting phenol or the like, attempts have been made to increase the surface renewability by rotary stirring as in the above-mentioned horizontal polymerization vessel. However, surprisingly, it has also been clarified that if polymerization is carried out using a polymerization vessel that satisfies the conditions of the present invention, rotational stirring is not necessarily required, and high-quality aromatic polycarbonate can be produced at a high polymerization rate. This is also a major feature of the present invention.

Hereinafter, the present invention will be described in detail. In the present invention, the aromatic dihydroxy compound is a compound represented by the following formula. HO-Ar-OH (wherein, Ar represents a divalent aromatic group) The divalent aromatic group Ar is preferably, for example, one represented by the following formula. -Ar ¹ -Y-Ar ^2- (wherein, Ar ¹ and Ar ² each independently represent a divalent carbocyclic or heterocyclic aromatic group having 5 to 70 carbon atoms, and Y represents carbon Represents a divalent alkane group having the number of 1 to 30.) In the divalent aromatic groups Ar ¹ and Ar ² , at least one hydrogen atom has another substituent which does not adversely influence the reaction, for example, halogen. Even those substituted by atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, phenyl groups, phenoxy groups, vinyl groups, cyano groups, ester groups, amide groups, nitro groups, etc. good.

Preferred specific examples of the heterocyclic aromatic group include an aromatic group having one or more ring-forming nitrogen, oxygen or sulfur atoms. The divalent aromatic groups Ar ¹ and Ar ² represent groups such as substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, and substituted or unsubstituted pyridylene. The substituent here is as described above. The divalent alkane group Y is, for example, an organic group represented by the following formula 1.

[0017]

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(Wherein R ¹ , R ² , R ³ , and R ⁴ each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms,
10 alkoxy groups, a cycloalkyl group having 5 to 10 ring carbon atoms, a carbocyclic aromatic group having 5 to 10 ring carbon atoms,
Represents a carbocyclic aralkyl group having 6 to 10 carbon atoms. k is 3
And R ⁵ and R ⁶ are independently selected for each X and independently of one another, hydrogen or C 1
And X represents an alkyl group, and X represents carbon. Also,
In R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ , other substituents such as a halogen atom and an alkyl having 1 to 10 carbon atoms are used as long as one or more hydrogen atoms do not adversely affect the reaction. It may be substituted by a group, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, a nitro group, or the like. Examples of such a divalent aromatic group Ar include those represented by the following formula (2).

[0019]

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(Wherein R ⁷ and R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyclo group having 5 to 10 ring carbon atoms) An alkyl group or a phenyl group, m and n
Is an integer of 1 to 4, and when m is 2 to 4, each R ⁷ may be the same or different, and n is 2 to 4
In this case, each R ⁸ may be the same or different. Further, the divalent aromatic group Ar may be represented by the following formula. —Ar ¹ —Z—Ar ² — (wherein, Ar ¹ and Ar ² are as described above, and Z is a single bond or —O—, —CO—, —S—, —SO 2 —, —SO—,
_{-COO -, - CON (R 1} ) - represents a divalent group, such as. Here, R ¹ is as described above. Examples of such a divalent aromatic group Ar include those represented by the following formula (3).

[0021]

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(In the formula, R ⁷ , R ⁸ , m and n are as described above.) The aromatic dihydroxy compound used in the present invention may be a single kind or two or more kinds. A typical example of the aromatic dihydroxy compound is bisphenol A. The diaryl carbonate used in the present invention is represented by the following chemical formula 4.

[0023]

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(Wherein, 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. ³ , in Ar ⁴ , one or more hydrogen atoms has another substituent that does not adversely affect the reaction;
For example, a halogen atom, an alkyl group having 1 to 10 carbon atoms,
It may be substituted by an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, a nitro group, or the like. A
r 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 described above. Preferred Ar ³
Examples of Ar ⁴ and Ar ⁴ include, for example,

[0026]

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A typical example of a diaryl carbonate is represented by the following formula (6).

[0028]

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(Wherein R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,
An alkoxy group having 10; a cycloalkyl group having 5 to 10 ring carbon atoms; or a phenyl group;
When p is 2 or more, each R ⁹ may be different, and when q is 2 or more,
Each R ¹⁰ may be different. Among these diphenyl carbonates, unsubstituted diphenyl carbonate, ditolyl carbonate, di-t
Symmetric diaryl carbonates, such as lower alkyl-substituted diphenyl carbonates such as -butylphenyl carbonate, are preferred, with diphenyl carbonate being the simplest diaryl carbonate being particularly preferred.

These diaryl carbonates may be used alone or in combination of two or more. The use ratio (charge ratio) of the aromatic dihydroxy compound and the diaryl carbonate varies depending on the type of the aromatic dihydroxy compound and the diaryl carbonate used, the polymerization temperature and other polymerization conditions, but the diaryl carbonate is used in 1 mol of the aromatic dihydroxy compound. On the other hand, usually 0.9 to 2.5 mol, preferably 0.95 to
2.0 moles, more preferably 0.98 to 1.5 moles. The number average molecular weight of the aromatic polycarbonate obtained by the method of the present invention is usually 500 to 10,000.
0, preferably in the range of 2000 to 30,000.

In the present invention, an aromatic polycarbonate is produced by using a polymerizer that performs polymerization while dropping along an interior material. In the present invention, the term "interior" refers to an object in which a polymer can fall along the surface of the interior. For example, a support for fixing an interior material to a polymerization vessel is regarded as an interior material if the polymer can fall along the support surface, and is not regarded as an interior material if the polymer cannot fall along the support surface. . Among the interior items,
In particular, an interior component vertically connected from the upper portion to the lower portion of the polymerization vessel is preferable. In this case, the connection means that the interior material may be in direct contact with the upper and lower portions of the polymerization reactor, or may be simply connected between the upper space of the polymerization reactor and the lower space of the polymerization reactor, and may be in direct contact with the polymerization reactor. You don't have to. Examples of such an interior material include a wire, a tube, a chain, a wire rope, a spring, and a flat plate that are vertically connected from the upper part to the lower part of the polymerization vessel. It is preferable that a plurality of such interior parts are installed in the polymerization vessel. It is also a preferable method to provide a perforated plate for supplying the polymer to the upper part of the polymerization vessel so as to drop the polymer along the interior material, and connect each hole of the perforated plate to the interior material. Other interior materials include a filler type.
Such interiors include, for example, Raschig rings, lessing rings, pole rings, Berl saddles, interlock saddles, Dixon packings, McMahon packings, heli packs, sulzer packings, Mela packs and the like.

In the present invention, the total surface area of the interior material is
It is the total area of the part where the polymer can fall along the surface, the total surface area S (m ² ) of the interior material,
It is necessary that the ratio S / V of each numerical value of (m ³ ) is in the range of 0.1 to 300. When the value of S / V is smaller than 0.1, the polymerization capacity per unit polymerization vessel capacity is decreased, and as a result, a large polymerization vessel is required, which is not preferable.
When the value of S / V is larger than 300, the amount of foreign substances in the aromatic polycarbonate to be produced increases. S /
V is preferably in the range of 0.2 to 200, more preferably 0.3 to 120.

In the present invention, the value of the clearance L (m) between the interior material and the inner wall surface of the polymerization vessel is determined by the following formula (I) with respect to the number average molecular weight Mn of the aromatic polycarbonate to be produced: L ≧ 5 × 10 ⁻⁶ It is necessary to use a polymerization vessel satisfying the relationship of Mn (I). Here, the inner wall surface of the polymerization vessel means the inner wall surface of the side surface of the polymerization vessel, and is, for example, a portion illustrated as the inner wall surface 2 of the polymerization vessel in FIGS. 3 (a) and 3 (b). The clearance between the interior 3 and the inner wall surface of the polymerization vessel 2 indicates the shortest distance 4 between the surface of the interior article and the inner wall surface of the polymerization vessel at the position closest to the interior wall surface of the polymerization vessel. When the value of the clearance L (m) does not satisfy the condition of the formula (I), it is impossible to produce an aromatic polycarbonate with few foreign substances.

When producing an aromatic polycarbonate according to the present invention, one polymerizer satisfying the conditions of the present invention may be used alone, or two or more polymerizers may be used in combination. It is also possible to produce an aromatic polycarbonate by combining a polymerization vessel satisfying the conditions of the present invention with another polymerization vessel. For example, a method of producing a prepolymer by polymerizing an aromatic dihydroxy compound and a diaryl carbonate in the initial stage of polymerization using a vertical stirring tank, and polymerizing the prepolymer using a polymerization vessel satisfying the conditions of the present invention. This is one of preferred embodiments of the present invention.

Specific examples of the polymerization vessel that can be used in the present invention will be described with reference to the drawings. However, the polymerization vessels that can be used in the present invention are not limited to these specific examples. FIG. 1 (a) is a cross-sectional view of a polymerization vessel 1 having a plurality of flat plates 7 and polymerizing while dropping a polymer 8 along the flat plates, and FIG. 1 (b) is viewed from above. FIG. The prepolymer introduced from the raw material supply port 5 is dispersed by the dispersing plate 6 into a plurality of flat plates 7 serving as the interior. From the polymer 8 falling along the flat plate 7,
An aromatic monohydroxy compound or the like evaporates from the evaporation surface 9. The inside of the polymerization vessel is controlled under reduced pressure, and the aromatic monohydroxy compound and the like, and the inert gas supplied from the gas supply port 10 as necessary, are supplied to the vent port 11.
Is more exhausted. The polymer having a higher degree of polymerization while falling is discharged from the outlet 12. The total surface area S (m ² ) of the plurality of flat plates 7 as interior parts and the capacity V of the polymerization vessel
The ratio S / V of each numerical value of (m ³ ) is in the range of 0.1 to 300, and the numerical value of the clearance L (m) between the surface of the flat plate 7 and the inner wall surface 2 of the polymerization vessel is the aromatic polycarbonate to be discharged. Satisfy the relationship of the formula (I) with respect to the number average molecular weight Mn. The discharged polymer can be supplied again to the raw material supply port 5 to further increase the molecular weight. The polymerization can be performed in a batch mode or a continuous mode. In the case of a batch method, the discharged polymer is repeatedly supplied to the raw material supply port 5.
It is also possible to carry out the polymerization while feeding the mixture. As a continuous method, a method in which a polymer is continuously supplied to the raw material supply port 5 and a polymer having a higher degree of polymerization is continuously extracted from the discharge port 12, or the discharged polymer is repeatedly supplied to the raw material supply port 5. At the same time, a new prepolymer is continuously supplied to the raw material supply port 5, a part of the discharged polymer is continuously extracted, and the remaining polymer is supplied again from the raw material supply port 5. The polymerization vessel is heated by a jacket or a heater and kept warm.

FIG. 2A shows a state in which a plurality of wires 13 are provided.
FIG. 2 is a cross-sectional view of a polymerization vessel 1 of a type in which polymerization is performed while dropping a polymer 8 along the wire;
(B) is a sectional view seen from above. The prepolymer introduced from the raw material supply port 5 is dispersed by the dispersing plate 6 to the plurality of wires 13 as the interior. From the polymer 8 that falls along the wire 13, the aromatic monohydroxy compound or the like evaporates from the evaporation surface 9. The inside of the polymerization vessel is controlled under reduced pressure, such as an aromatic monohydroxy compound,
An inert gas or the like supplied from the gas supply port 10 as necessary is discharged from the vent port 11. The polymer having a higher degree of polymerization while falling is discharged from the outlet 12. The ratio S / V of each numerical value of the total surface area S (m ² ) of the plurality of wires as the interior parts and the capacity V (m ³ ) of the polymerization vessel is 0.1.
And the numerical value of the clearance L (m) between the wire surface and the inner wall surface of the polymerization vessel satisfies the relationship of the formula (I) with respect to the number average molecular weight Mn of the discharged aromatic polycarbonate. . The discharged polymer can be supplied again to the raw material supply port 5 to further increase the molecular weight. The polymerization can be performed in a batch mode or a continuous mode. In the case of performing a batch method, it is also possible to polymerize while repeatedly supplying the discharged polymer to the raw material supply port 5. As a continuous method, a method of continuously supplying a polymer to the raw material supply port 5 and continuously extracting a polymer having a higher degree of polymerization from the discharge port 12, or a method of repeatedly supplying the discharged polymer to the raw material supply port 5. At the same time, a new prepolymer is continuously supplied to the raw material supply port 5, a part of the discharged polymer is continuously extracted, and the remaining polymer is supplied again from the raw material supply port 5. In addition,
The polymerization vessel is heated by a jacket or heater, etc.
And it is kept warm.

In the present invention, when an aromatic dihydroxy compound is reacted with a diaryl carbonate to produce an aromatic polycarbonate, the reaction temperature is usually 5
The temperature is selected in the range of 0 to 350 ° C, preferably 100 to 290 ° C. As the reaction proceeds, an aromatic monohydroxy compound is produced, and by removing this compound out of the reaction system, the reaction rate can be increased. Therefore, by introducing an inert gas such as nitrogen, argon, helium, carbon dioxide or a lower hydrocarbon gas which does not adversely affect the reaction, the generated aromatic monohydroxy compound is removed together with these gases. A method and a method of performing the reaction under reduced pressure are preferably used. Preferred reaction pressure is the type and molecular weight of the aromatic polycarbonate to be produced,
Although it varies depending on the polymerization temperature and the like, for example, when producing an aromatic polycarbonate from bisphenol A and diphenyl carbonate, in the range where the number average molecular weight is 1000 or less, the range of 50 mmHg to normal pressure is preferable, and the number average molecular weight is 1000 to 2000. In the range, 3 mmHg to 5
The range of 0 mmHg is preferable, and the number average molecular weight is 2,000.
In the above range, the pressure is preferably 20 mmHg or less, and 10 mHg or less.
mHg or less is more preferable, and especially 2 mmHg or less is preferable.

The method of carrying out the reaction under reduced pressure and while introducing the above-mentioned inert gas is also preferably used. The transesterification can be carried out without adding a catalyst,
In order to increase the polymerization rate, the reaction is carried out in the presence of a catalyst, if necessary. The polymerization catalyst is not particularly limited as long as it is used in this field, but hydroxides of alkali metals or alkaline earth metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide are used. Kind;
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 Alkali metal or alkaline earth metal hydrogen compounds such as calcium iodide; alkali metal or alkaline earth metal alkoxides such as lithium methoxide, sodium ethoxide, calcium methoxide; lithium phenoxide, sodium phenoxide, magnesium phenoxide, LiO -Ar-
Alyloxides of alkali metals or alkaline earth metals such as OLi and NaO-Ar-ONa (Ar is an aryl group); Organic acid salts of alkali metals or alkaline earth metals such as lithium acetate, calcium acetate and sodium benzoate; Oxidation Zinc compounds such as zinc, zinc acetate and zinc phenoxide; boron oxide, boric acid, sodium borate, trimethyl borate, tributyl borate, triphenyl borate, (R ¹ R ² R ³ R ⁴ ) NB (R ¹ R ² R ³ R ⁴ ) represented by ammonium borates, (R ¹ R ² R ³ R ⁴ ) PB
Boron compounds such as phosphonium borates represented by (R ¹ R ² R ³ R ⁴ ) (R ¹ , R ² , R ³ and R ⁴ are as described in the above formula 1); silicon oxide; Silicon compounds such as sodium silicate, tetraalkylsilicon, tetraarylsilicon, diphenyl-ethyl-ethoxysilicon; germanium oxide, germanium tetrachloride,
Germanium compounds such as germanium ethoxide and germanium phenoxide; tin compounds combined with alkoxy or aryloxy groups such as tin oxide, dialkyltin oxide, dialkyltin carboxylate, tin acetate and ethyltin tributoxide, and organotin compounds Tin compounds; lead compounds such as lead oxide, lead acetate, lead carbonate, basic carbonate, alkoxide or aryloxide of lead and organic lead; quaternary ammonium salts, quaternary phosphonium salts, quaternary arsonium salts Onium compounds such as; antimony oxide, antimony compounds such as antimony acetate; manganese acetate, manganese carbonate,
Manganese compounds such as manganese borate; titanium compounds such as titanium oxide, titanium alkoxide or aryloxide; zirconium acetate, zirconium oxide, zirconium alkoxide or aryloxide;
Examples of the catalyst include zirconium compounds such as zirconium acetylacetone.

When using catalysts, these catalysts may be used alone or in combination of two or more. The amount of these catalysts to be used is generally selected in the range of 10 ^-8 to 1% by weight, preferably 10 ^-7 to 10 ^-1 % by weight, based on the aromatic dihydroxy compound as the raw material. The material of the polymerization vessel for achieving the method of the present invention is not particularly limited, and is usually selected from stainless steel, nickel, glass lining and the like.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to examples. Note that the molecular weight is a number average molecular weight (hereinafter, referred to as M) measured by gel permeation chromatography (GPC).
Abbreviated as n. ). The color was measured by a CIELAB method at a test piece thickness of 3.2 mm, and the yellowness was indicated by a b ^* value. The amount of minute foreign matter in the range of 0.5 μm to 20 μm is
The measurement was performed using a foreign substance measuring device manufactured by Hiac Royco. The polymerization capacity of the polymerization vessel is defined as Q (ton / hr), the amount of increase in the number average molecular weight in the polymerization vessel is Mn ^* , and the internal volume of the polymerization vessel is V (m ³ ). , Q × Mn ^* × V.

[0041]

Example 1 A reaction was carried out using a cylindrical polymerization vessel having a plurality of flat plates as shown in FIG. This polymerization vessel had an inner diameter of 0.3 m, a volume capacity of the polymerization vessel of 0.59 m ³ , and a thickness of 2 mm, a width of 0.03 m and a height of 8 as an interior product.
8 SUS316L flat plates, the total surface area of the interior is 4.1 m ² , and the value of S / V is 7.0. The clearance between the flat plate closest to the inner wall surface of the polymerization vessel and the inner wall surface of the polymerization vessel is 0.068 m. The polymer supplied to the polymerization vessel is uniformly distributed on both sides of each flat plate by the dispersion plate. The outside of the polymerization vessel is a jacket and is heated with a heating medium.

In this polymerization vessel, bisphenol A and diphenyl carbonate (molar ratio of bisphenol A to 1.0)
The prepolymer of the aromatic polycarbonate of Mn6000 produced from 6) is continuously supplied at a flow rate of 0.02 ton / hr, and the aromatic polycarbonate is continuously supplied from the outlet at 255 ° C. and a pressure of 0.4 Torr. Polymerization was carried out while extracting. After 50 hours, the aromatic polycarbonate discharged from the discharge port had a Mn of 11,000, and was a transparent polymer having no color (b ^* value of 3.4). The numerical value of the clearance L (m) satisfies the condition of the formula (I). The amount of minute foreign matter in the range of 0.5 μm to 20 μm was as small as 980 particles / g. The polymerization capacity of the polymerization vessel was 171 (ton / m ³ · hr).

[0043]

Examples 2 to 6 Prepolymers of aromatic polycarbonates of different Mn, prepared from bisphenol A and diphenyl carbonate, were prepared in various polymerization reactors having flat plates as interior materials in the same manner as in Example 1 under various polymerization conditions. The polymerization was carried out. The results are summarized in Tables 1 and 2.

[0044]

Comparative Example 1 Example 1 except that the clearance between the flat plate closest to the inner wall surface of the polymerization vessel and the inner wall surface of the polymerization vessel was 0.05 m.
The polymerization was carried out in exactly the same manner as described above. The results are shown in Tables 1 and 2.

[0045]

Comparative Example 2 Polymerization was carried out in exactly the same manner as in Example 5 except that the number of flat plates was 800. The results are shown in Tables 1 and 2.

[0046]

Comparative Example 3 A horizontal stirring tank having an inner volume of 0.6 m ³ and a length of 3 m having two stirring shafts having a rotation diameter of 0.25 m was prepared in Example 3.
The same aromatic polycarbonate prepolymer as in Example 1 was continuously supplied to carry out polymerization at a stirring rotation speed of 10 rpm. The supply amount of the prepolymer, the polymerization temperature, and the polymerization pressure were exactly the same as in Example 3. After 50 hours, the Mn of the aromatic polycarbonate discharged from the polymerization vessel was 5,100, and the polymerization capacity of the polymerization vessel was 47 (ton / m ³ · hr). Coloring was observed in the obtained aromatic polycarbonate (b ^* value 3.8). 0.5μm to 20μ
The amount of minute foreign matter in the range of m was 3,980 particles / g.

[0047]

Example 7 A reaction was carried out using a cylindrical polymerization vessel having a plurality of wires as shown in FIG. This polymerization vessel has an inner diameter of 0.3 m, a volume capacity of the polymerization vessel of 0.59 m ³ , and is made of SUS3 having a thickness of 1 mm and a length of 8 m as an interior material.
It has 150 16L wires, the surface area of the interior is 3.8 m ² , and the numerical value of S / V is 6.4. The clearance between the wire closest to the inner wall surface of the polymerization reactor and the inner wall surface of the polymerization reactor is 0.035 m. The polymer supplied to the polymerization vessel is evenly distributed to each wire by the dispersion plate. The outside of the polymerization vessel is a jacket and is heated with a heating medium.

In this polymerization vessel, bisphenol A and diphenyl carbonate (molar ratio of bisphenol A to 1.0 were used).
The prepolymer of the aromatic polycarbonate of Mn2100 produced from 7) was continuously supplied at a flow rate of 0.025 ton / hr, and the aromatic polycarbonate was continuously supplied from the outlet at 245 ° C. and a pressure of 0.5 Torr. Polymerization was carried out while extracting. The aromatic polycarbonate discharged from the outlet after 50 hours is Mn5000,
It was a clear polymer without color (b ^* value 3.3).
The numerical value of the clearance L (m) satisfies the condition of Expression (1). The amount of minute foreign matters in the range of 0.5 μm to 20 μm was as small as 850 / g. The polymerization capacity of the polymerization vessel is 1
24 (ton / m ³ · hr).

[0049]

Examples 8 to 11 Prepolymers of aromatic polycarbonates of different Mn, prepared from bisphenol A and diphenyl carbonate, were prepared under various polymerization conditions by using various polymerization reactors each having a wire as the interior as in Example 7. The polymerization was carried out. The results are summarized in Tables 3 and 4.

[0050]

Comparative Example 4 Example 9 except that the number of wires was six.
The polymerization was carried out in exactly the same manner as described above. The results are shown in Tables 3 and 4.

[0051]

Example 12 Example 10 was repeated except that bisphenol A was replaced with a prepolymer of Mn4900 aromatic polycarbonate prepared from 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane. The reaction was performed under exactly the same conditions as described above. After 50 hours, the aromatic polycarbonate discharged from the outlet was Mn1
0200, indicating that the polymer was a transparent polymer having no color (b ^* value: 3.4). The numerical value of the clearance L (m) satisfies the condition of Expression (1). 0.5 μm to 20 μm
The amount of the minute foreign matter in the range was as small as 1250 / g. The polymerization capacity of the polymerization vessel is 64 (ton / m ³ · hr)
Met.

[0052]

Examples 13 to 16 Instead of bisphenol A, a prepolymer of Mn6000 aromatic polycarbonate produced using a mixture of bisphenol A and various aromatic dihydroxy compounds other than bisphenol A is used as the aromatic dihydroxy compound. Except for Example 1
Polymerization was carried out under exactly the same conditions as described above. However, the ratio of bisphenol A to the aromatic dihydroxy compound other than bisphenol A was 1: 1 in molar ratio, and the total amount was equivalent to the bisphenol A of Example 1 in equimolar. Table 5 summarizes the results.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

[Table 5]

[0058]

EFFECTS OF THE INVENTION Poor extraction efficiency of phenol, high power of stirring, breakage of molecular chains due to shear, reduction of the rate of increase in molecular weight, coloration of polymer, mixing of decomposition products into polymer after long heat history No problems such as low volumetric efficiency, more high-quality aromatic polycarbonate in a polymerization vessel as small as possible, without coloring or generating foreign matter, at a high polymerization rate, and industrially preferable It can be manufactured by the method.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view as viewed from the front, and FIG. 1B is a cross-sectional view as viewed from above, schematically showing an example of a polymerization vessel for achieving the method of the present invention.

FIGS. 2A and 2B are a schematic cross-sectional view as viewed from the front and a cross-sectional view as viewed from above, schematically illustrating an example of a polymerization vessel for achieving the method of the present invention.

FIGS. 3A and 3B are explanatory diagrams of a polymerization reactor as viewed from the front and (b) illustrating a polymerization reactor as viewed from above, for explaining the inner wall and clearance L (m) of the polymerization reactor as defined in the present invention. .

[Explanation of symbols]

 1. 1. Polymerizer main body 2. Polymerizer inner wall Interior items 4. Clearance L (m) 5. Raw material supply port 6. Dispersion plate 7. Flat plate 8. Polymer 9. Evaporation surface 10. Gas supply port 11. Vent port 12. Outlet 13. Wire

Claims (2)

(57) [Claims] 1. An aromatic dihydroxy compound and a diaryl
While dropping along the interior from the carbonate,
Manufacture aromatic polycarbonate using a polymerizer
In doing so, the total surface area S (m^Two), Polymerization vessel
Content V (m ^Three) Is between 0.1 and 300.
Between the interior surface and the inner wall of the polymerization vessel.
Aromatic polycarbonate produced by the numerical value of Alance L (m)
The following formula (I) with respect to the number average molecular weight Mn of the salt: L ≧ 5 × 10^-6Using a polymerization reactor satisfying the relationship of Mn (I).
A method for producing an aromatic polycarbonate. 2. The method according to claim 1, wherein the interior is an interior which is vertically connected from the upper part of the polymerization vessel to the lower part of the polymerization vessel, and wherein a plurality of the interior parts are used. A method for producing an aromatic polycarbonate.