JPH073004A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To efficiently produce a polycarbonate excellent in qualities such as hydrolysis resistance. CONSTITUTION:A method for producing a polycarbonate by subjecting (A) a dihydroxy compound and (B) a carbonic acid diester to a transesterification reaction is characterized by using (C) a mixture of an active hydrogen-containing nitrogen heterocyclic compound with a metal compound as a catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polycarbonate. More specifically, the present invention relates to a method for efficiently producing a polycarbonate which can significantly improve the reaction rate without impairing hydrolysis resistance and has an excellent color tone.

[0002]

2. Description of the Related Art Generally, as a method for producing a polycarbonate (hereinafter referred to as PC), a method in which an aromatic dihydroxy compound such as bisphenol A is directly reacted with phosgene (interfacial method) Alternatively, there is known a method (melting method) in which an aromatic dihydroxy compound such as bisphenol A and a carbonic acid diester such as diphenyl carbonate are subjected to a transesterification reaction in a molten state. In the method of manufacturing PC, the interfacial method must use toxic phosgene,
There are various problems such as corrosion of production equipment by chlorine-containing compounds such as hydrogen chloride and sodium chloride produced as by-products, and difficulty in separating impurities such as sodium hydroxide mixed in the resin that adversely affect the physical properties of the polymer. .

On the other hand, the melting method has an advantage that PC can be manufactured at a lower cost than the interfacial method, but since it is usually reacted at a high temperature of 280 to 310 ° C. for a long time, It has a big drawback that it cannot escape from the coloring problem of the resin. In addition, since a basic catalyst is often used, there is a problem that the resulting PC has poor hydrolysis resistance. In such a melting method, various improved techniques have been proposed in order to reduce this coloring. For example, JP-B-61-39972 and JP-A-63-2.
No. 23036 discloses a method of using a specific catalyst. Further, JP-A-61-151236 and JP-A-62-158719 disclose methods of adding an antioxidant in the latter stage of the reaction. In JP-A-61-62522 and the like, a twin-screw vent type kneading extruder is disclosed in the latter half of the reaction, and in JP-A-2-1539.
No. 25, etc. disclose a process-improving technique such as using a horizontal stirring polymerization tank. Furthermore, JP-A-2
Japanese Patent Laid-Open No. 175722 discloses a method of keeping the content of hydrolyzable chlorine in a monomer below a certain level.
Further, in order to improve the hydrolysis resistance of the obtained PC,
It has been conventionally known to neutralize with a volatile acid such as dimethylsulfate, and recently, a technique of neutralizing an excess acid with an epoxy by neutralizing with an acid such as p-toluenesulfonic acid. (Japanese Patent Laid-Open No. 4-175368) is known. However, the problem of quality has not been completely solved yet, and the fact is that a satisfactory PC has not yet been obtained.

[0004]

Therefore, the present inventors have
In view of the above situation, the inventors have earnestly conducted research to develop a method for producing a polycarbonate that is excellent in hydrolysis resistance, can improve a reaction rate, and can efficiently produce a high-quality PC. As a result, they have found that the above problem can be solved by using a mixture of a specific active hydrogen-containing nitrogen-containing heterocyclic compound and a metal compound as a catalyst in the method for producing PC by transesterification. The present invention has been completed based on such findings. That is, the present invention uses a mixture of an active hydrogen-containing nitrogen-containing heterocyclic compound and a metal compound as a (C) catalyst in producing a polycarbonate from a (A) dihydroxy compound and a (B) carbonic acid diester by a transesterification method. The present invention provides a method for producing a polycarbonate.

In the present invention, there are various dihydroxy compounds used as the component (A). For example, selected from aromatic dihydroxy compounds, aliphatic dihydroxy compounds, bisesters of aromatic dihydroxy compounds, bisesters of aliphatic dihydroxy compounds, carbonates of aromatic dihydroxy compounds, and carbonates of aliphatic dihydroxy compounds. At least one compound. The aromatic dihydroxy compound used as one of the components (A) has the general formula (I)

[0006]

[Chemical 1]

[Wherein R is a halogen atom (for example, chlorine, bromine, fluorine, iodine) or an alkyl group having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, n-butyl group, Isobutyl group, amyl group, isoamyl group, hexyl group, etc.) and when this R is plural,
They may be the same or different,
m is an integer of 0-4. Z is a single bond, an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms (for example, methylene group, ethylene group, propylene group, butylene group, penterylene group, hexylene group, ethylidene group, isopropylidene group). Ridene group, etc.), C5-15
Cycloalkylene group or cycloalkylidene group having 5 to 15 carbon atoms (for example, cyclopentylene group, cyclohexylene group, cyclopentylidene group, cyclohexylidene group, etc.), or -S-, -SO-, -SO ₂ -, -O
-, -CO- bond or general formula (II) or (II ')

[0008]

[Chemical 2]

The bond represented by ] The aromatic dihydroxy compound represented by these is mentioned. Examples of such aromatic dihydroxy compounds include bis (4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A ); 2,2-
Bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) octane; 2,2-bis (4-hydroxyphenyl) phenylmethane; 2,2-
Bis (4-hydroxy-1-methylphenyl) propane; 1,1-bis (4-hydroxy-t-butylphenyl) propane; 2,2-bis (4-hydroxy-3-bromophenyl) propane; 2,2 -Bis (4-hydroxy-3,5-dimethylphenyl) propane; 2,2-bis (4-hydroxy-3-chlorophenyl) propane;
2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane; 2,2-bis (4-hydroxy-3,2
Bis (hydroxyaryl) alkanes such as 5-dibromophenyl) propane; 1,1-bis (4-hydroxyphenyl) cyclopentane; 1,1-bis (4-hydroxyphenyl) cyclohexane; 1,1-bis (4 −
Bis (hydroxyaryl) cycloalkanes such as hydroxyphenyl) -3,5,5-trimethylcyclohexane; 4,4-dihydroxydiphenyl ether;
Dihydroxy aryl ethers such as 4,4′-dihydroxy-3,3′-dimethylphenyl ether;
4'-dihydroxydiphenyl sulfide; 4,4'-
Dihydroxydiaryl sulfides such as dihydroxy-3,3′-dimethyldiphenyl sulfide; 4,
4'-dihydroxydiphenyl sulfoxide; 4,4 '
-Dihydroxyaryl sulfoxides such as dihydroxy-3,3'-dimethyldiphenyl sulfoxide;
4,4'-dihydroxydiphenyl sulfone; 4,4 '
-Dihydroxydiaryl sulfones such as dihydroxy-3,3'-dimethyldiphenyl sulfone, dihydroxybenzene, halogen- and alkyl-substituted dihydroxybenzenes, for example 1,4-dihydroxy-2,5-dichlorobenzene; 1,4-dihydroxy-3- Methylbenzene etc. are mentioned.

There are various kinds of aliphatic dihydroxy compounds as the component (A). For example, butane-1,4-diol; 2,2-dimethylpropane-
1,3-diol; hexane-1,6-diol; diethylene glycol; triethylene glycol; tetraethylene glycol; octaethylene glycol; dipropylene glycol; N, N-methyldiethanolamine; cyclohexane-1,3-diol; cyclohexane -1,4-diol; 1,4-dimethylolcyclohexane; p-xylylene glycol; 2,2-bis-
Ethoxylated or propoxylated products of (4-hydroxycyclohexyl) -propane and dihydric alcohols or phenols such as bis-oxyethyl-bisphenol A; bis-oxyethyl-tetrachlorobisphenol A or bis-oxyethyl-tetrachlorohydroquinone. To be

Examples of the bisester of an aromatic dihydroxy compound, the bisester of an aliphatic dihydroxy compound, the carbonate of an aromatic dihydroxy compound, or the carbonate of an aliphatic dihydroxy compound used as the component (A) include The bisesters of the above compounds have the general formula (III)

[0012]

[Chemical 3]

[Wherein R ¹ represents a residue obtained by removing two hydroxyl groups from the above aliphatic dihydroxy compound, and R ² represents an alkyl group having 1 to 6 carbon atoms or 4 to 4 carbon atoms.
A cycloalkyl group having 7 is shown. ] The compound represented by the general formula (IV)

[0014]

[Chemical 4]

[In the formula, Ar ¹ represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound, and R ² has the same meaning as described above. ] The compound represented by the general formula (V)

[0016]

[Chemical 5]

[In the formula, Ar ² represents an aryl group, and R ¹ is the same as above. ] Or a compound represented by the general formula (V
I)

[0018]

[Chemical 6]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] The compound represented by these is mentioned. Further, the carbonates of the above compounds have the general formula (VII)

[0020]

[Chemical 7]

[In the formula, R ¹ and R ² are the same as defined above. ] The compound represented by the general formula (VIII)

[0022]

[Chemical 8]

[In the formula, R ² and Ar ¹ are the same as defined above. ] The compound represented by the general formula (IX)

[0024]

[Chemical 9]

[In the formula, R ¹ and Ar ² are the same as defined above. ] The compound or general formula (X) represented by

[0026]

[Chemical 10]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] The compound represented by these is mentioned. In the present invention, as the dihydroxy compound as the component (A), the above compounds are appropriately selected and used. Among these, it is preferable to use bisphenol A which is an aromatic dihydroxy compound. When bisphenol A is used, an adduct of bisphenol A and phenol or a mixture of the adduct and phenol can be used. By using the adduct in this way, bisphenol A having high purity can be obtained, which is effective.

On the other hand, in the present invention, there are various carbonic acid diesters used as the component (B). For example, it is at least one compound selected from diaryl carbonate compounds, dialkyl carbonate compounds or alkylaryl carbonate compounds. The diaryl carbonate compound used as one of the components (B) has the general formula (XI)

[0029]

[Chemical 11]

[In the formula, Ar ² is the same as described above. ] The compound or general formula (X) represented by

[0031]

[Chemical 12]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] It is a compound represented by these. The dialkyl carbonate compound has the general formula (XII)

[0033]

[Chemical 13]

[In the formula, R ² is the same as above. ] Or a compound represented by the general formula (VIII)

[0035]

[Chemical 14]

[In the formula, R ² and Ar ¹ are the same as defined above. ] It is a compound represented by these. The alkyl aryl carbonate compound has the general formula (XIII)

[0037]

[Chemical 15]

[In the formula, R ² and Ar ² are the same as defined above. ] Or a compound represented by the general formula (XIV)

[0039]

[Chemical 16]

[In the formula, R ² , Ar ¹ and Ar ² are the same as defined above. ] It is a compound represented by these. Here, examples of the carbonic acid diaryl compound include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, and bisphenol A bisphenyl carbonate.
Examples of the dialkyl carbonate compound include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, bisphenol A bismethyl carbonate and the like. Examples of the alkyl aryl carbonate compound include methylphenyl carbonate, ethylphenyl carbonate, butylphenyl carbonate, cyclohexylphenyl carbonate, bisphenol A methylphenyl carbonate and the like. Among these, diphenyl carbonate is particularly preferable. In the present invention,
As the carbonic acid diester as the component (B), the above compounds are appropriately selected and used, but among these, diphenyl carbonate is preferably used.

The production method of the present invention is to obtain a polycarbonate by a transesterification reaction using the components (A) and (B). In order to produce a polycarbonate by this transesterification reaction, in addition to the above-mentioned components (A) and (B), if necessary, the following terminal terminator can be used. Specific examples of such an end terminating agent include on-butylphenol; mn-
Butylphenol; pn-butylphenol; o-isobutylphenol; m-isobutylphenol; p-
Isobutylphenol; ot-butylphenol; m
-T-butylphenol; pt-butylphenol;
nn-pentylphenol; mn-pentylphenol; pn-pentylphenol; nn-hexylphenol; mn-hexylphenol; pn-hexylphenol; o-cyclohexylphenol; m
-Cyclohexylphenol; p-cyclohexylphenol; o-phenylphenol; m-phenylphenol; p-phenylphenol; nn-nonylphenol; mn-nonylphenol; pn-nonylphenol; o-cumylphenol; m- Cumylphenol; p-cumylphenol; o-naphthylphenol;
m-naphthylphenol; p-naphthylphenol;
2,6-di-t-butylphenol; 2,5-di-t-
Butylphenol; 2,4-di-t-butylphenol; 3,5-di-t-butylphenol; Formula

[0042]

[Chemical 17]

2,5-dicumylphenol represented by:
3,5-dicumylphenol; as a chroman derivative,
For example, the expression

[0044]

[Chemical 18]

Examples thereof include monohydric phenols. Of these phenols, although not particularly limited in the present invention, p-tert-butylphenol; p-cumylphenol; p-phenylphenol and the like are preferable. Also, the formula

[0046]

[Chemical 19]

Examples thereof include compounds represented by Furthermore, in the present invention, phloroglucin; trimellitic acid; 1,1,1-tris (4-hydroxyphenyl) ethane; 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl], if necessary. -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene; α,
α ′, α ″ -tris (4-hydroxyphenyl) -1,
3,5-triisopropylbenzene; isatin bis (o
-Cresol) or the like can be used as a branching agent.

In the production method of the present invention, a polycarbonate is produced by a transesterification reaction using the above-mentioned component (A), component (B) and other components such as a terminal terminator or a branching agent. A major feature of the reaction is the use of a mixture of an active hydrogen-containing nitrogen-containing heterocyclic compound and a metal compound as the (C) catalyst. Here, there are various active hydrogen-containing nitrogen-containing heterocyclic compounds used as one of the catalysts of the component (C). For example, substitution of a hydroxyl group, an amino group, a mercapto group, a formyl group or the like as the active hydrogen is possible. Examples thereof include compounds having a group such as pyridines, quinolines, quinoxalines, cinnolines, pyrazines, pyrimidines, triazines and pyridazines. Here, examples of the pyridines include 2-hydroxypyridine, 4-hydroxypyridine, 2-aminopyridine, 4-aminopyridine,
Examples thereof include 2-mercaptopyridine, 4-mercaptopyridine and the like, as well as substitution products in which various substituents are introduced. Examples of the quinolines include 2-hydroxyquinoline, 4-hydroxyquinoline, 5-hydroxyquinoline, 7-hydroxyquinoline, 1-hydroxyisoquinoline, 3-hydroxyisoquinoline, 6-hydroxyisoquinoline, 8-hydroxyisoquinoline,
2-aminoquinoline, 4-aminoquinoline, 5-aminoquinoline, 7-aminoquinoline, 1-aminoisoquinoline, 3-aminoisoquinoline, 6-aminoisoquinoline, 8-aminoisoquinoline, 2-mercaptoquinoline, 4-mercaptoquinoline, Examples thereof include 5-mercaptoquinoline, 7-mercaptoquinoline, 1-mercaptoisoquinoline, 3-mercaptoisoquinoline, 6-mercaptoisoquinoline, 8-mercaptoisoquinoline and the like, and substituents into which various substituents are introduced. And as said quinoxaline, for example, 2-hydroxyquinoxaline, 5-hydroxyquinoxaline, 6-
Hydroxyquinoxaline, 2-aminoquinoxaline, 5
-Aminoquinoxaline, 6-aminoquinoxaline, 2-
Examples thereof include mercaptoquinoxaline, 5-mercaptoquinoxaline, 6-mercaptoquinoxaline and the like, as well as substitution products in which various substituents are introduced.

Further, as the cinnolines, for example, 4-hydroxycinnoline, 5-hydroxycinnoline, 8-hydroxycinnoline, 4-aminocinnoline, 5-aminocinnoline, 8-aminocinnoline, 4
-Mercaptocinnoline, 5-mercaptocinnoline,
Examples thereof include 8-mercaptocinnoline and the like, and substitution products in which various substituents are introduced. Examples of the pyrazines include 2-hydroxypyrazine, 2-aminopyrazine, 2-mercaptopyrazine, and the like, as well as substitution products in which various substituents are introduced. Examples of the pyrimidines include 2-hydroxypyrimidine, 4
-Hydroxypyrimidine, 2-aminopyrimidine, 4-
Examples include aminopyrimidine, 2-mercaptopyrimidine, 4-mercaptopyrimidine and the like, as well as substitution products in which various substituents are introduced. Examples of the triazines include 2-hydroxytriazine, 2-aminotriazine, 2-mercaptotriazine and the like, and substituents in which various substituents are introduced. Examples of the pyridazines include 3-hydroxypyridazine, 4-hydroxypyridazine, 3-aminopyridazine, 4-aminopyridazine, 3-mercaptopyridazine, 4-mercaptopyridazine, and substitutions in which various substituents are introduced. The body.

On the other hand, there are various metal compounds used as one of the catalysts of the component (C). Specifically, a simple substance of alkali metal or alkaline earth metal, oxide, hydroxide, amide compound, alcoholate, phenolate, or basic metal oxide such as ZnO, PbO, Sb ₂ O ₃ , organic titanium compound , Soluble manganese compounds, Ca, Mg, Zn, Pb, Sn, Mn, Ti,
Cd, Co acetate or nitrogen-containing basic compound and boron compound, nitrogen-containing basic compound and alkali (earth) metal compound, nitrogen-containing basic compound and alkali (earth) metal compound and boron compound, etc. Examples include catalysts. Among these, metal compounds preferably used include, for example, manganese acetate [Mn (AcO) ₂ ], calcium acetate [Ca (AcO) ₂ ], zinc acetate [Zn (AcO) ₂ ],
Examples thereof include cobalt acetate [Co (AcO) ₂ ], magnesium acetate [Mg (AcO) ₂ ], and cobalt acetylacetonate [Co (acac) ₂ ].

In the present invention, in the transesterification reaction of the dihydroxy compound of the component (A) and the carbonic acid diester of the component (B), the active hydrogen-containing nitrogen-containing heterocyclic compound of the component (C) and the metal compound are used as catalysts. The mixture is 1 to 1 with respect to the dihydroxy compound of the component (A).
It is used in a proportion of 0 ^-6 mol / mol, preferably 10 ^-1 to 10 ^-5 mol / mol. The mixture of the component (C) is 10
^If it is less than ^-6 mol / mol, the effect is not exhibited. Moreover, it leads to cost increase exceeding 1 mol / mol, and it is not necessary to use beyond this. And, the active hydrogen-containing nitrogen-containing heterocyclic compound and the metal compound are usually 0.1:
It is used in a mixing ratio of 1 to 1,000: 1, preferably 1: 1 to 100: 1.

In the production method of the present invention, specifically, the reaction proceeds according to a known transesterification method. The procedure and conditions of the production method of the present invention will be specifically described below. First,
As the component (A), the aromatic dihydroxy compound, the aliphatic dihydroxy compound, the bisester of the aromatic dihydroxy compound, the bisester of the aliphatic dihydroxy compound, the carbonate of the aromatic dihydroxy compound or the carbonate of the aliphatic dihydroxy compound. And the carbonic acid diester which is the above-mentioned diaryl carbonate compound, dialkyl carbonate compound or carbonic acid alkylaryl compound as the component (B) is such that the carbonic acid diester is 1 to 1.5 times the mole of the dihydroxy compound. Transesterification occurs in a ratio. Depending on the situation, the amount of the carbonic acid diester is preferably 1.02 to 1.20 times the molar amount of the dihydroxy compound, which is slightly excessive.

In the above-mentioned transesterification reaction, the amount of the terminal terminator consisting of the above-mentioned monohydric phenol is
With respect to 1 mol of the dihydroxy compound which is the component (A),
When the amount is in the range of 0.05 mol% to 10 mol%, the hydroxyl group terminal of the obtained polycarbonate is sealed, so that a polycarbonate having sufficiently excellent heat resistance and water resistance can be obtained. The total amount of such a terminal terminator composed of the monohydric phenol may be added to the reaction system in advance. Further, it may be added in part to the reaction system in advance and the rest may be added as the reaction progresses. Further, in some cases, the whole amount may be added to the reaction system after the transesterification reaction of the dihydroxy compound (A) and the carbonic acid diester (B) partially proceeds.

In carrying out the transesterification reaction in the present invention, the reaction temperature is not particularly limited, but usually 100 ° C to
It is in the range of 330 ° C, preferably 180 ° C to 300
℃, more preferably gradually as the reaction progresses 18
A good method is to raise the temperature from 0 ° C to 300 ° C. If the transesterification reaction is lower than 100 ° C., the progress of the reaction is slow, and if it exceeds 330 ° C., thermal degradation of the polymer occurs, which is not preferable. The reaction pressure is set according to the vapor pressure of the monomer used and the reaction temperature. This is not limited as long as it is set so that the reaction is efficiently performed. Usually, in the initial stage of the reaction, 1 to 5
The atmospheric pressure or pressure up to 0 atm (760 to 38,000 torr) is kept, and in the latter stage of the reaction, the pressure is reduced,
In most cases, the final value is preferably 0.01 to 100 torr. Further, the reaction time may be such that it reaches the target molecular weight, and is usually about 0.2 to 10 hours.

The above reaction is carried out in the absence of an inert solvent, but if necessary, 1 to
It may also be carried out in the presence of 150% by weight of an inert solvent. Here, examples of the inert solvent include aromatic compounds such as diphenyl ether, halogenated diphenyl ether, benzophenone, polyphenyl ether, dichlorobenzene, and methylnaphthalene, carbon dioxide, gases such as dinitrogen monoxide and nitrogen, and chlorofluorohydrocarbons. Examples thereof include alkanes such as ethane and propane, cyclohexane, cycloalkanes such as tricyclo (5,2,10) -decane, cyclooctane and cyclodecane, and alkenes such as ethene and propene.

In the present invention, an antioxidant can be used if necessary. Specific examples include phosphorus-based antioxidants such as tris (nonylphenyl) phosphite, trisphenylphosphite, 2-ethylhexyldiphenylphosphite, trimethylphosphite, triethylphosphite, tricresylphosphite, and triarylphosphite. There is.

In the present invention, as the reaction proceeds, phenols corresponding to the carbonic acid diester used,
Alcohols or their esters and inert solvent are desorbed from the reactor. These desorbed substances can be separated, purified and recycled for use, and it is preferable to have a facility for removing them. And, the present invention can be carried out batchwise or continuously, and any equipment can be used. In the case of continuous production, it is preferable to use at least two reactors and set the above reaction conditions. The material of the reactor used in the present invention contains the metal as described above, and the structure thereof is not particularly limited, but may have a normal stirring function. However, since the viscosity increases in the latter stage of the reaction, it is preferable to have a high-viscosity stirring function. Further, the shape of the reactor is not limited to a tank type, and may be an extruder type reactor or the like.

The PC thus obtained may be granulated as it is, or may be molded by using an extruder or the like. Further, the PC obtained by the present invention can be used by blending well-known additives such as a plasticizer, a pigment, a lubricant, a release agent, a stabilizer and an inorganic filler.
Further, the obtained PC can be blended with polymers such as polyolefin, polystyrene, polyester, polysulfonate, polyamide and polyphenylene oxide. In particular, it is effective when used in combination with polyphenylene ether, polyether nitrile, terminal-modified polysiloxane compound, modified polypropylene, modified polystyrene or the like having an OH group, COOH group, NH ₂ group or the like at the end.

[0059]

The present invention will be further described in detail with reference to Examples and Comparative Examples. The present invention is not limited to the examples below. Examples 1 to 6 and Comparative Examples 1 to 4 Bisphenol A (0.3 g, 0.0013 mol) and diphenyl carbonate (0.56 g, 0.0026 mol) were placed in an ampoule, and the active hydrogen-containing nitrogen-containing heterocyclic compound was used as a catalyst. After adding the metal compound according to Table 1, a stirrer chip was put and the tube was sealed under a nitrogen environment. The ampoule tube was placed in an oil path kept at 150 ° C. and reacted for 1 hour. After completion of the reaction, the produced phenol was quantified by gas chromatography to obtain the reaction rate. The results are shown in Table 1. The catalyst Mn (AcO) ₂ was added as an aqueous solution.

[0060]

[Table 1]

Examples 7 to 13 The procedure of Example 1 was repeated, except that the active hydrogen-containing nitrogen-containing heterocyclic compound and the metal compound were added as catalysts according to Table 2. The reaction rate is shown in Table 2.

[0062]

[Table 2]

Examples 14 to 18 and Comparative Examples 5 to 8 Bisphenol A (BPA) 2 was added to a nickel steel autoclave (with a stirrer) having an internal volume of 1,400 ml.
28 g (1.00 mol) and diphenyl carbonate 225
After charging g (1.05 mol) and adding a nitrogen-containing heterocyclic compound containing active hydrogen and a metal compound as a catalyst according to Table 3, nitrogen substitution was carried out 5 times. 180 ° C for the mixture
The bisphenol A and the diphenyl carbonate were melted by heating up to. Next, the temperature was set to 220 ° C., stirring was started at the same time, and a small amount of nitrogen was passed through, and at the same time, the produced phenol started to be distilled off. The reaction was held at 220 ° C for 1 hour. Then, the temperature was raised to 240 ° C., the degree of vacuum was gradually raised to 10 mmHg, and the reaction was performed for 1 hour. Further, the temperature was 270 ° C., the degree of vacuum was 1 mmHg, and the reaction was carried out for 1 hour to obtain a viscous and transparent condensate. The viscous and transparent condensate obtained was dissolved in methylene chloride, and the viscosity average molecular weight was measured. Further, the obtained viscous and transparent condensate was crushed and pelletized at 220 to 270 ° C. using an extruder. The obtained pellets were press-molded, and the YI and hydrolysis resistance of the press plate (thickness 3 mm) were measured. The measurement results are shown in Table 3.

[0064]

[Table 3]

[0065]

[Table 4]

The viscosity average molecular weight and hydrolysis resistance were measured as follows. 1) Viscosity average molecular weight (Mv) The viscosity of a methylene chloride solution at 20 ° C was measured with an Ubbelohde type viscosity tube, and the intrinsic viscosity [η] was calculated from this, and then calculated by the following formula. [Η] = 1.23 × 10 ⁻⁵ × Mv ^0.83 2) Hydrolysis resistance The press plate (thickness 3 mm) was visually observed for 48 hours after being exposed to 121 ° C. steam for 48 hours.

[0067]

As described above, according to the present invention, in the transesterification reaction of (A) dihydroxy compound and (B) carbonic acid diester, (C) a mixture of a nitrogen-containing heterocyclic compound containing active hydrogen and a metal compound as a catalyst. By using, it is possible to significantly improve the reaction rate without impairing the hydrolysis resistance, and it is possible to produce a polycarbonate of excellent quality. Therefore, the present invention can be effectively and widely used as a method for industrially producing a polycarbonate by a transesterification method.

Claims (5)

[Claims] 1. A method for producing a polycarbonate from a (A) dihydroxy compound and a (B) carbonic acid diester by a transesterification method, wherein a mixture of an active hydrogen-containing nitrogen-containing heterocyclic compound and a metal compound is used as the (C) catalyst. A method for producing a polycarbonate, comprising: 2. A nitrogen-containing heterocyclic compound containing active hydrogen,
The method for producing a polycarbonate according to claim 1, which is a pyridine or a quinoline containing active hydrogen. 3. The metal compound is Mn, Ti, Ca, Z.
The method for producing a polycarbonate according to claim 1, which is a compound of a metal selected from n, Co and Mg. 4. The method for producing a polycarbonate according to claim 1, wherein the metal compound is a metal salt of acetic acid. 5. The method for producing a polycarbonate according to claim 1, wherein the metal compound is a manganese compound.